91
Fans & Pumps Fans & Pumps ADNAN JOUNI ADNAN JOUNI RCREEE Energy Audit in Building Tunis, 1st – 5th June 2010 1
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Fans amp PumpsFans amp PumpsADNAN JOUNIADNAN JOUNI
RCREEE Energy Audit in Building
Tunis 1st ndash 5th June 2010
1
1 1 General Introduction General Introduction 2 Fans amp Blowers2 Fans amp Blowers3 Pumps amp Pumping systems3 Pumps amp Pumping systems
Contents
2
General IntroductionGeneral Introduction
Pumps and fans are probably the devices the most frequently used in our life
Both are necessary to move material and energy
3
General IntroductionGeneral Introduction
In building sector their usage is essential to secure comfort and welfare
Energy saving concerns 2 levels
bull The device itself
bull The removed energy or material
4
5
Fans amp BlowersFans amp Blowers
Equipment Specific Ratio Pressure rise (mmWg)
Fans up to 111 1136
Blowers 111to 120 1136 ndash2066
Comparison
6
Introduction
Types of fans and blowers
Energy audit of Fans
ContentsContents
7
IntroductionIntroductionWhat are Fan systemsWhat are Fan systems
Any device that produces a current of air by the movement of broad surfaces can be called a fan
Fans are similar in many respects to pumps
Both are turbo machines that transfer energy to a flowing fluid
It is easy to distinguish between fans and pumps pumps handle liquids fans handle gasses
Broadly speaking the function of a fan is to propel displace or move air or gas
IntroductionIntroduction
Fan components
System resistance
Fan curve
Operating point
Fan laws
8
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
1 1 General Introduction General Introduction 2 Fans amp Blowers2 Fans amp Blowers3 Pumps amp Pumping systems3 Pumps amp Pumping systems
Contents
2
General IntroductionGeneral Introduction
Pumps and fans are probably the devices the most frequently used in our life
Both are necessary to move material and energy
3
General IntroductionGeneral Introduction
In building sector their usage is essential to secure comfort and welfare
Energy saving concerns 2 levels
bull The device itself
bull The removed energy or material
4
5
Fans amp BlowersFans amp Blowers
Equipment Specific Ratio Pressure rise (mmWg)
Fans up to 111 1136
Blowers 111to 120 1136 ndash2066
Comparison
6
Introduction
Types of fans and blowers
Energy audit of Fans
ContentsContents
7
IntroductionIntroductionWhat are Fan systemsWhat are Fan systems
Any device that produces a current of air by the movement of broad surfaces can be called a fan
Fans are similar in many respects to pumps
Both are turbo machines that transfer energy to a flowing fluid
It is easy to distinguish between fans and pumps pumps handle liquids fans handle gasses
Broadly speaking the function of a fan is to propel displace or move air or gas
IntroductionIntroduction
Fan components
System resistance
Fan curve
Operating point
Fan laws
8
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
General IntroductionGeneral Introduction
Pumps and fans are probably the devices the most frequently used in our life
Both are necessary to move material and energy
3
General IntroductionGeneral Introduction
In building sector their usage is essential to secure comfort and welfare
Energy saving concerns 2 levels
bull The device itself
bull The removed energy or material
4
5
Fans amp BlowersFans amp Blowers
Equipment Specific Ratio Pressure rise (mmWg)
Fans up to 111 1136
Blowers 111to 120 1136 ndash2066
Comparison
6
Introduction
Types of fans and blowers
Energy audit of Fans
ContentsContents
7
IntroductionIntroductionWhat are Fan systemsWhat are Fan systems
Any device that produces a current of air by the movement of broad surfaces can be called a fan
Fans are similar in many respects to pumps
Both are turbo machines that transfer energy to a flowing fluid
It is easy to distinguish between fans and pumps pumps handle liquids fans handle gasses
Broadly speaking the function of a fan is to propel displace or move air or gas
IntroductionIntroduction
Fan components
System resistance
Fan curve
Operating point
Fan laws
8
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
General IntroductionGeneral Introduction
In building sector their usage is essential to secure comfort and welfare
Energy saving concerns 2 levels
bull The device itself
bull The removed energy or material
4
5
Fans amp BlowersFans amp Blowers
Equipment Specific Ratio Pressure rise (mmWg)
Fans up to 111 1136
Blowers 111to 120 1136 ndash2066
Comparison
6
Introduction
Types of fans and blowers
Energy audit of Fans
ContentsContents
7
IntroductionIntroductionWhat are Fan systemsWhat are Fan systems
Any device that produces a current of air by the movement of broad surfaces can be called a fan
Fans are similar in many respects to pumps
Both are turbo machines that transfer energy to a flowing fluid
It is easy to distinguish between fans and pumps pumps handle liquids fans handle gasses
Broadly speaking the function of a fan is to propel displace or move air or gas
IntroductionIntroduction
Fan components
System resistance
Fan curve
Operating point
Fan laws
8
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
5
Fans amp BlowersFans amp Blowers
Equipment Specific Ratio Pressure rise (mmWg)
Fans up to 111 1136
Blowers 111to 120 1136 ndash2066
Comparison
6
Introduction
Types of fans and blowers
Energy audit of Fans
ContentsContents
7
IntroductionIntroductionWhat are Fan systemsWhat are Fan systems
Any device that produces a current of air by the movement of broad surfaces can be called a fan
Fans are similar in many respects to pumps
Both are turbo machines that transfer energy to a flowing fluid
It is easy to distinguish between fans and pumps pumps handle liquids fans handle gasses
Broadly speaking the function of a fan is to propel displace or move air or gas
IntroductionIntroduction
Fan components
System resistance
Fan curve
Operating point
Fan laws
8
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
6
Introduction
Types of fans and blowers
Energy audit of Fans
ContentsContents
7
IntroductionIntroductionWhat are Fan systemsWhat are Fan systems
Any device that produces a current of air by the movement of broad surfaces can be called a fan
Fans are similar in many respects to pumps
Both are turbo machines that transfer energy to a flowing fluid
It is easy to distinguish between fans and pumps pumps handle liquids fans handle gasses
Broadly speaking the function of a fan is to propel displace or move air or gas
IntroductionIntroduction
Fan components
System resistance
Fan curve
Operating point
Fan laws
8
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
7
IntroductionIntroductionWhat are Fan systemsWhat are Fan systems
Any device that produces a current of air by the movement of broad surfaces can be called a fan
Fans are similar in many respects to pumps
Both are turbo machines that transfer energy to a flowing fluid
It is easy to distinguish between fans and pumps pumps handle liquids fans handle gasses
Broadly speaking the function of a fan is to propel displace or move air or gas
IntroductionIntroduction
Fan components
System resistance
Fan curve
Operating point
Fan laws
8
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
IntroductionIntroduction
Fan components
System resistance
Fan curve
Operating point
Fan laws
8
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
9
IntroductionIntroduction
Fan Network Components
Outlet Diffusers
Baffles
Heat Exchanger
Turning Vanes (typically used on short radius elbows)
Variable Frequency Drive
Inlet Vanes
Filter
Belt Drive
Motor Controller
Centrifugal Fan
Motor
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
10
IntroductionIntroductionSystem Resistance
bull Sum of static pressure losses in systembull Increases with square of flow rate
calculated
Actual withsystemresistance
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
11
IntroductionIntroduction Fan Curves
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
12
IntroductionIntroduction
Operating PointFan curve and system curve intersection
Flow Q1 at pressure P1 and
fan speed N1
Move to flow Q2 by reducing fan
speed
Move to flow Q2 by closing
damper (increase system
resistance)
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
13
IntroductionIntroduction
Fan LawsMinimizing Energy through Fan selection
Fan Affinity Laws
Pre
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
14
ContentsContents
Introduction
Types of fans and blowersEnergy Audit of Fans
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
15
Types of Fans amp BlowersTypes of Fans amp Blowers
Types of fans
bull Centrifugal
bull Axial
Types of blowers
bull Centrifugal
bull Positive displacement
Type of FanPeak Efficiency
Range
Centrifugal fans
Airfoil Backward curvedinclined
79-83
Modified radial 72-79
Radial 69-75
Pressure blower 58-68
Forward curved 60-65
Axial fans
Vane axial 78-85
Tube axial 67-72
Propeller 45-50
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
16
Types of Fans amp BlowersTypes of Fans amp Blowers
Centrifugal Fans
bull Advantagesbull High pressure and temp
bull Simple design
bull High durability
bull Efficiency up to 75
bull Large running clearances
bull Disadvantages bull Suited for lowmedium
airflow rates only
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
17
Types of Centrifugal Fans
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
18
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Centrifugal Fans
Backward-inclined
bull Advantagesbull Operates with changing
static pressure
bull Suited for high flow and forced draft services
bull Efficiency gt85
bull Disadvantagesbull Not suited for dirty airstreams
bull Instability and erosion risk
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
19
Types of Fans amp BlowersTypes of Fans amp Blowers
bull Work like airplane propeller bull Blades create aerodynamic lift
bull Air is pressurized
bull Air moves along fan axis
bull Popular compact low cost and light weight
bull Applicationsbull Ventilation (requires reverse airflow)
bull Exhausts (dust smoke steam)
Axial Fans
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
20
Types of Fans amp BlowersTypes of Fans amp Blowers
Example of Axial Fans ndash Tube axial fans
bull Advantagesbull Pressures to overcome duct
losses
bull Suited for medium-pressure high airflow rates
bull Quick acceleration
bull Disadvantagesbull Expensive
bull Moderate noise
bull Low energy efficiency 65
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
21
Types of Fans amp BlowersTypes of Fans amp Blowers
Blowers
bull Difference with fans
bull Much higher pressures lt120 kgcm2
bull Used to produce negative pressures for industrial vacuum systems
bull Types
bull Centrifugal blower
bull Positive displacement
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
22
ContentsContents
Introduction
Types of fans and blowers
Energy Audit of Fans
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
23
Energy Audit of FansEnergy Audit of Fans
In Most situations the potential of Energy Saving is more than 30
IntroductionExample for the distribution of cost over the life cycle of fans
Maintenance (5)
Capital 8)
Energy (87)
Fans are the main consumer for auxiliary Systems
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
24
Energy Audit of FansEnergy Audit of Fans
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
25
Data Collection
Energy Audit of FansEnergy Audit of Fans
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect Details of the fans and ducting system Collect the schematic diagram network of the ducting system Collect Performance characteristics of all fans Compile design previous best and last energy audit values with respect to fans and draft system If the fans are operated in parallel then it is advised to collect the performance curve for the parallel operation Air quality and pressure equipments at the users as per the design requirements
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
26
Energy Audit of FansEnergy Audit of Fans
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Stroboscope To measure the speed of the driven equipment and motor
Sling hygrometer or digital hygrometer
Anemometer Pitot tubes
On line instruments ndash (calibrated)
Digital Manometer of suitable range and appropriate probes for measurement of pressure head and velocity head
Additional pressure gauges with appropriate range of measurement and calibrated before audit
Instruments Required
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
27
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made
Energy consumption pattern of fans
Motor electrical parameters (kW kVA Pf A V Hz) of fans
Fan operating parameters to be measuredmonitored for each Fan are
1 Discharge flow rate
2 Pressure (suction amp discharge)
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
28
Energy Audit of FansEnergy Audit of Fans
Measurements amp observations to be made3 Damper position guide vane position VSD Setting
4 Temperature of fluid handled
5 Load variation
6 Fan operating hours and operating schedule
7 Pressure drop in the system
8 Pressure drop and temperature variation across the equipment
9 Fan Motor speed
Oxygen content flow temperature and pressure measurement across in exhaust gas path
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
29
Energy Audit of FansEnergy Audit of Fans
Energy consumption pattern
If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern (Collect data for 12 months)
Work out the total consumption of fans to arrive at percentage to the total consumption of the auxiliary consumption
If the energy meters are not installed to fans instantaneous measurements can be carried out based on the loading pattern daily consumption can be worked out
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
30
Energy Audit of FansEnergy Audit of Fans
Fan Operating Efficiency Evaluation
The parameters to be studied in detailed are
Air gas rates of fans main ducts
Static pressure and dynamic pressure and total pressure
Power consumption of fan (for estimating the operating efficiency of the fans)
Monitor present flow control system and frequency of control valve operation if any (for application of variable speed drives)
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
31
Energy Audit of FansEnergy Audit of Fans
Fans Performance assessmentbull Static pressure
ndash Potential energy put into the system by the fan
bull Velocity pressurendash Pressure arising from air flowing through the duct
This is used to calculate velocity
bull Total pressure ndash Static pressure + velocity pressure
ndash Total pressure remains constant unlike static and velocity pressure
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
32
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
33
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
34
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Fan static kW = Q in m3 s x static pr developed by fan in mmwc
102
Fan static efficiency Fan static kW x 100 Input kW to motor x m
=
Fan mechanical Efficiency Fan total kW x 100 Input kW to motor x m
=
Parameter Details Unit
Q Air flow rate m3 s
Static pressure Difference between discharge amp suction pressure mmwc
Fan static total kW Static total power consumption of the fan kW
Input kW to motor Measured power consumption of the motor kW
m Efficiency of the motor at operating load
Total pressure Difference between discharge amp suction pressure mmwc
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
35
Fan Operating Efficiency Evaluation
Energy Audit of FansEnergy Audit of Fans
Corrected air density = 273 X 1293
273 + Air temperature in 0 C
Parameter Details Unit
Cp Pitot tube constant 085 or as given by manufacturer
Density of air or gas at test condition Kg m3
Velocity in m s =Cp x 2 x 981 x Diff velocity pr in mmwc x
Volumetric flow (Q) m3s = Velocity ms x Area m2
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
36
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
The investigations for abnormality are to be carried out for problems
Enlist scope of improvement with extensive physical checks observations
Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as- Replacement of fans Impeller replacement VFD application
Cost analysis with savings potential for taking improvement measures
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
37
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Recirculation
Damper
IGV
VFD
Ideal
Power
Flow
25 7550 100
100
75
50
25
Inlet Guide Vanes
Variable Frequency Drive
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
38
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
System characteristics and Fan curves Impact of speed reduction
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
39
Fan Performance AnalysisEnergy Audit of FansEnergy Audit of Fans
Visual survey of insulation amp the ducting system
Insulation status (measure the surface temperature with the aid of surface thermocouple infrared pyrometer or by using thermal imaging cameras)
Bends and ducting status
Physical condition of insulation Identification of locations where action is required to improve the insulation (provide with detailed techno-economics)
Improvement options for ducting systems if any
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
40
Exploration of Energy Conservation OpportunitiesEnergy Audit of FansEnergy Audit of Fans
Improvement of systems and drives Use of energy efficient fans
Change of impeller with energy efficient impeller
Correcting inaccuracies of the fan sizing
Use of high efficiency motors
Fan speed reduction by pulley diameter modifications for optimization
Option of two speed motors or variable speed drives for variable duty conditions
High Performance Lubricants The low temperature fluidity and high temperature stability of high performance lubricants can increase energy efficiency by reducing frictional losses
Use of energy efficient transmission systems (Use of latest energy efficient transmission belts)
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
41
Exploration of Energy Conservation Opportunities
Energy Audit of FansEnergy Audit of Fans
Improvement in operations
Minimizing excess air level in combustion systems to reduce fan load
Minimizing air in-leaks in hot or cold flue gas path to reduce fan load
Minimizing system resistance and pressure drops
improvements in duct system Insulation aspects
Measures to up keep the performance
After the identification of energy conservation measures detailed techno-economic evaluation has to be carried out
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
42
Case StudyA fan is used to draw air through a bag filter 1048707 Flow rate is 90 m3s at a static pressure of 80 mm water column (WC)1048707 65 mm WC is the static pressure across the bag filter1048707 Motor power drawn is 120 kW1048707 Motor efficiency is 861048707 Impeller diameter is 70 mm1048707 RPM is 1000
After consultation we decided to replace the bag filter with an electrostatic precipitator (ESP) 1048707 Static pressure across the ESP is 20 mm WC1048707 Flow rate increased by 201048707 The flow rate can be brought back to 90 m3s by two options (a) Impeller trimming and (b) Reduced pulley diameter to reduce the RPM
Energy Audit of FansEnergy Audit of Fans
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
43
We must Calculate the following1 Fan static efficiency before installation of the ESP2 The new impeller diameter if the impeller is trimmed that would result in a reduction in fanefficiency of 53 The new RPM that would result in a fan efficiency of 604 Which of the two options is more energy efficient
Case Study
Energy Audit of FansEnergy Audit of Fans
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
44
1 Fan static efficiency before installation of the ESPPower input at fan shaft = 120 x 086 = 1032 kWFan efficiency = 90 x 80(102 x 1032) = 68
2 New impeller diameter if the impeller is trimmedNew fan static efficiency = 68 - 5 = 63New static = 80 ndash 65 + 20 = 35 mm WCNew flow rate Q = 90 m3s x 12 = 108 m3sStatic pressure at a flow of 90 m3s with ESP installedQ1 Q2 = (H1H2)2 result H2 = 32 mmPower required at the fan shaftFan static efficiency 063 = (90 x 32) (102 x power)Power developed at fan shaft = 448 kW
New impeller diameter (D2)(D1 D2) = (kW1 kW2) 1 3 result D2 = 53 mm
Case Study
Energy Audit of FansEnergy Audit of Fans
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
45
3 Calculate the new RPM that would result in a fan efficiency of 60Power required at fan shaft060 = 90 x 32 102 x Power required at fan shaftPower required at fan shaft = 47 kWNew RPM (N2) (N1 N2) = (kW1 kW2) 1 3
N2 = 769 RPM4 Determine which of the two options is more energy efficientPower required by impeller trimming = 448 kWPower required by reducing RPM = 47 kWTherefore impeller trimming is the more energy efficient option
Case Study
Energy Audit of FansEnergy Audit of Fans
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
46
PumpsPumps
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
47
ContentsContents
Introduction
Type of pumps
Energy Audit of Pumps
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
48
IntroductionIntroduction
bull 20 of worldrsquos electrical energy demand
bull Used for
bull Domestic commercial industrial and agricultural services
bull Municipal water and wastewater services
What are Pumping Systems
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
49
IntroductionIntroduction
Objective of pumping system
What are Pumping Systems
bull Transfer liquid from source to destination
bull Circulate liquid around a system
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
50
IntroductionIntroduction
bull Main pump componentsbull Pumps
bull Prime movers electric motors diesel engines air system
bull Piping to carry fluid
bull Valves to control flow in system
bull Other fittings control instrumentation
bull End-use equipmentbull Heat exchangers tanks hydraulic machines
What are Pumping Systems
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
51
Pressure (Pa) 1000xSpecific gravity
bull Head
bull Resistance of the system
bull Two types static and friction
bull Static head
bull Difference in height between source and destination
bull Independent of flow
bull Static head at certain pressure
Pumping System Characteristics
IntroductionIntroduction
Head (m) =
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
52
IntroductionIntroduction
In most cases
Total head = Static head + friction head
Pumping System Characteristics
System head
Flow
Static head
Friction head
Systemcurve
bull Friction head
bull Resistance in pipe and fittings
bull Depends on size pipes pipe fittings flow rate nature of liquid
bull Proportional to square of flow rate
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
53
IntroductionIntroduction
Pump operating point
Pumping System Characteristics
bull Duty point rate of flow at certain head
bull Pump operating point intersection of pump curve and system curve
Flow
Head
Static head
Pump performance curve
System curve
Pump operating point
Pump performance curve
Relationship between head and flow
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
54
IntroductionIntroduction
Pump suction performance
bull Cavitation or vaporization bubbles inside pump
bull If vapor bubbles collapse
bull Erosion of vane surfaces
bull Increased noise and vibration
bull Choking of impeller passages
bull Net Positive Suction Head (NPSH)
bull NPSH Available how much pump suction exceeds liquid vapor pressure
bull NPSH Required pump suction needed to avoid cavitation
Pumping System Characteristics
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
55
IntroductionIntroduction
Pumping System Characteristic curves
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
56
IntroductionIntroduction
Pumping System Characteristics
Pumps in parallel Curves
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
57
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
58
Type of PumpsType of Pumps
Classified by operating principle
Pump Classification
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
DynamicPositive
Displacement
Centrifugal Special effect Rotary Reciprocating
Internal gear
External gear
LobeSlide vane
Others (eg Impulse Buoyancy)
Pumps
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
59
Type of PumpsType of Pumps
Positive Displacement Pumps
bull For each pump revolutionbull Fixed amount of liquid taken from one end
bull Positively discharged at other end
bull If pipe blockedbull Pressure rises
bull Can damage pump
bull Used for pumping fluids other than water
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
60
Type of PumpsType of Pumps
Dynamic pumps
bull Mode of operationbull Rotating impeller converts kinetic energy
into pressure or velocity to pump the fluid
bull Two typesbull Centrifugal pumps pumping water in
industry ndash 75 of pumps installed
bull Special effect pumps specialized conditions
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
61
bull Liquid forced into impeller
bull Vanes pass kinetic energy to liquid liquid rotates and leaves impeller
bull Volute casing converts kinetic energy into pressure energy
Type of PumpsType of Pumps
Centrifugal Pumps
How do they work
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
62
Type of PumpsType of Pumps
Centrifugal Pumps
Impeller
bull Main rotating part that provides centrifugal acceleration to the fluid
bull Number of impellers = number of pump stages
bull Impeller classification direction of flow suction type and shapemechanical construction
Shaft
bull Transfers torque from motor to impeller during pump start up and operation
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
63
Impellers
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
64
Contents PumpsContents Pumps
Introduction
Type of pumps
Energy Audit of Pumps
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
65
Energy Audit of PumpsEnergy Audit of Pumps
Example for the distribution of cost over the life cycle of a water-based pump system
Maintenance (5)
Capital 10)
Energy (85)
In Most situations the potential of Energy Saving is more than 30
Introduction
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
66
Energy Audit of PumpsEnergy Audit of Pumps
Steps Involved
Data collection
Observations and Analysis
Exploration for energy conservation measures
Report preparation
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
67
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
Collect detailed design specification amp operating parameters Make Type Model Fluid characteristics Rated Flow Inlet pressure Efficiency motor characteristics Regulation systems
Collect the above information for all pumps in the water circuitCollect the Performance Characteristics curves of all pumps
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
68
Compile design previous best and last energy audit values of the pumping system being audited
If the pumps are operated in parallel then it is advised to collect the performance curves for the parallel operation of the pumps
Schematic diagram of Water pumping network (which depict the source pumps in operation amp stand by line sizes and users)
Water and pressure equipments at the users as per the design requirements
Brief description of the system in which pumps are used
Energy Audit of PumpsEnergy Audit of Pumps
Data Collection
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
69
Energy Audit of PumpsEnergy Audit of Pumps
Instruments Required
Power Analyzer Used for measuring electrical parameters such as kW kVA pf V A and Hz
Temperature Indicator amp Probe
Pressure Gauge To measure operating pressure and pressure drop in the system
Stroboscope To measure the speed of the driven equipment and motor
Ultra sonic flow meter or online flow meter
The above instruments can be used in addition to the calibrated online plant instruments
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
70
Energy Audit of PumpsEnergy Audit of Pumps
Parameters to be measured Energy consumption pattern of pumps (daily monthly yearly consumption)
Motor electrical parameters (kW kVA Pf A V Hz) for individual pumps
Pump operating parameters to be monitored for each pump
Discharge Flow Head (suction amp discharge) Valve position Temperature Load variation Simultaneous power parameters of pumps Pumps operating hours and operating schedule Pressure drop in the system (between discharge and user point) Pressure drop and temperatures across the users (heat exchangers condensers etc) Pump Motor speed Actual discharge pressure and required prevailing pressure at the user end User area pressure of operation and requirement
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
71
Energy Audit of PumpsEnergy Audit of Pumps
Observations amp Measurements Operating efficiency and performance evaluation of pumps
Flow distribution
System Details Detailed interactions (plant personnel) have to be carried out to get familiarization for system detail and operational details The brief system should be briefed in the report
Energy consumption Pattern If the plant is monitoring the energy consumption it is suggested to record the data and monitor the daily and monthly consumption pattern
Collect the past energy consumption data (month wise for at least 12 months daily consumption for about a week for different seasons daily Consumption during the audit period)
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
72
Performance parameters for water pumps
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
73
Performance parameters for water pumps contd
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
74
Pump hydraulic power can be calculated by the formula
Hydraulic kW = Q x Total Head (hd ndash hs) x x g
1000Parameter Details Unit
Q Water flow rate m3s
Total head Difference between discharge head hd amp suction head hs m
Density of water or fluid being pumped Kgm3
g Acceleration due to gravity m2s
Pump efficiency Pump = Hydraulic power
Pump shaft power
Pump shaft power = Hydraulic power x Motor
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
75
Energy Audit of PumpsEnergy Audit of PumpsEfficiency amp Performance Evaluation of the Pumps
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
76
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Compare the actual values with the design performance test values if any deviation is found list the factors with the details and suggestions to over come
Compare the specific energy consumption with the best achievable value (considering the different alternatives) Investigations to be carried out for problematic areas
Enlist scope of improvement with extensive physical checks observations Based on the actual operating parameters enlist recommendations for action to be taken for improvement if applicable such as
Replacement of pumps
Impeller replacement
Impeller trimming
Variable speed drive application etc
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
77
Energy Audit of PumpsEnergy Audit of Pumps
Avoiding Over sizing of Pump
Head
Head
Partially
closed valve
Const Speed
A
B
C
Meters
Pump Efficiency 77
82
Pump Curve at
Full open valve
System Curves
Operating Points
500300
50 m
70 m
Static
42 m
Flow (m3hr)
Oversize Pump
Required Pump
Energy Conservation Opportunities
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
78
286 kW
148 kW
Avoiding Over sizing of Pump by impeller trimming
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
79
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Provision of variable speed drive
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
80
Energy Audit of PumpsEnergy Audit of PumpsEnergy Conservation Opportunities
Improvement of systems and drives
Use of energy efficient pumps
Replacement of inefficient pumps
Trimming of impellers
Correcting inaccuracies of the Pump sizing
Use of high efficiency motors
Integration of variable speed drives into pumps
High Performance Lubricants lubricants can increase energy efficiency by reducing frictional losses
Booster pump application
Centralization decentralization
Categorizing according to the pressure requirement
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
81
Case Study
In a commercial Building a clear water Pump hasIn a commercial Building a clear water Pump has
Parameter Design Operating
Flow Q (msup3h) 800 550
Head H (m WC) 55 24(after delivery valve)
Power P (kW) 160 124
RPM 1485 1485
Water flow rate varies from 500 msup3h to 700 msup3hPump flow rate has been reduced by partially closing the delivery valve Motor efficiency is 93
Energy Audit of PumpsEnergy Audit of Pumps
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
82
1 Calculate the operating efficiency
2 Explain what would be the best option to obtain the required flow rate variation
3 Calculate the power savings if the options suggested under question 2 would reduce the flow rate of the pump is 550 msup3h
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
83
SOLUTION1 Calculate the operating efficiencyEfficiency of the pump = (550 x 24 x 981) (3600 x 124 x 093)= 03867 = 38672 Explain what would be the best solutionThe pump is operating at a poor efficiency of 3867 due to throttling of the flow Since the pump discharge requirement varies from 500 msup3h to 700 msup3h the ideal option would be to operate with a variable speed drive (VSD)
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
84
3 Calculate the power savings According to affinity laws1048707 Relationship Q and RPM Q1Q2 = N1N21048707 Relationship H and RPM H1H2 = (N1N2)2
1048707 Relationship P and RPM P1P2 = (N1N2)3
For a flow rate Q1 = 550 msup3h the reduced speed of pump (N1 in RPM) would be N1 = 1021 RPMPower would be P1 = 52 kWPower saving = 124 kW - 52 kW = 72 kW
Case Study
Energy Audit of PumpsEnergy Audit of Pumps
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
Good Practices
85
GP1
bullA waste-fuelled heating plant fed two networks
which supply an industrial area and a residential
area
bullAn analysis of the pumps used to supply networks
showed that the pumps were all run continuously at
high power although the pumping power required
was often very low
Energy Audit of PumpsEnergy Audit of Pumps
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
86
System optimisation measuresComplete separation of the pumps from the mains supply
when they are switched off
Replacement of existing pumps with smaller highly
efficient pumps
Use of variable speed drive for operation at adjustable
speeds
Installation of high efficiency motors
Installation of the new pumps and variable speed drive
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
87
Energy savings and efficiency parameters
bullElectricity savings 64 or 325000 kWh pa
bullCost savings euro 32500 pa
bullInvestment euro 67000
bullPayback period 21 years
bullReturn on investment 48
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
88
GP2
bullA combined heat and power plant provides a district (houses
hospitals welfare and handicapped facilities commercial
kitchen and a laundry ) heat via a district heating network
bullThe energy audit focused on the optimization of the main
district heating pumps in the power supply centre The
analysis showed considerable potential to optimize the pump
control system which until now has been regulated by hand
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
89
Systems optimisation measuresbullHydraulic alignment of the district heating network
bullInstallation of a proportional control system for the
pumps
bullUse of variable speed drive for operation at adjustable
speeds
bullReplacement of the two network pumps
bullUse of high efficiency motors
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
90
Energy savings and efficiency parameters
bullElectricity savings 39 or 129000 kWh pa
bullCost savings euro 14100 pa
bullInvestment euro 41700
bullPayback period 3 years
bullReturn on investment 31
Good Practices
Energy Audit of PumpsEnergy Audit of Pumps
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
91
THANK YOUTHANK YOU
FORFOR
YOUR ATTENTIONYOUR ATTENTION
