Ea of cw, ct & cond. system

A PRACTICAL APPROACH

to

D.Pawan Kumar

And

R.Virendra

ENERGY AUDIT IN CW, CT & CONDENSER SYSTEM

inTHERMAL POWER STATIONS

1.0 BACKGROUND

Cooling Water Circuit and System performance, holds the key in maintaining optimum vacuum in a thermal or a GT combined cycle plant. In current times, there is an increasing demand on power plant professionals, to address concurrently, complex tasks like ; Cooling water Consumption optimization, Achieving vacuum conditions and Optimizing power consumption in CW pumps and CT fans, despite plant side variations, like frequency, cooling water quality, availability, load variations, O & M demands, etc. While it is a challenge, experiences show that with the level of infrastructure and information available at most sites, it should be possible to conduct a reasonably detailed and functional energy audit, deploying in-house resources, to bring out improvement options.

2.0 AUDIT FOCUS

CW / CT system and condenser vacuum being focal points for energy audit study, the various improvement issues addressed in the CW audit include ;

2.1 Condenser Related

Cleanliness of tube surfaces

Tube leakages

High inlet water temperature

CW flow adequacy

2.2 CW Pump Related

Efficiency of CW pumps Fore bay level inadequacy Mains frequency related CW flow tapping for other purposes Parallel operations and effects

2.3 Cooling Tower Related

Approach, range of cooling towers L/G ratio of cooling towers Tuning scope in cooling towers, with

seasonal variations with regard to water load, CT fan blade angle, etc.

Maintenance of fills Quality of Cooling Water and COC

improvement CT fan blade material such as FRP/GRP, etc.

2.4 Overall Optimization related such as ;

Optimize CW pump operations with respect to thermal load

Optimizing L/G ratios during various seasons

Optimize CW pump efficiency through need based maintenance, retrofit, replacement options.

Optimize condenser operations through O & M

3.0 Based on experiences at various plants

The following steps are envisaged as illustrative help tools for the CW / CT audit teams in conduct of energy audit in thermal power plants and GT based combined cycle plants.

3.1 Scope of Audit

The scope of audit pertains to Energy Audit of Cooling Water System including Cooling Towers & Condenser is made into systems as given below : CW System : Audit for water consumption Cooling Tower : Audit for CT effectiveness Condenser : Audit for condenser heat load, CW flow &

Vacuum The energy audit on above system will be carried out to determine main features such as :

1. Consumption of circulating water flow 2. Performance of CW pumps w.r.t. CW flow3. CT effectiveness and L/G ratio4. Performance of condenser w.r.t. heat load and vacuum and CW

pressure drop across condenser.5. Comparison of measured performance with reference to

designed / rated values.6. Recommendations based on the performance of the above

system.

3.2 Methodology for Energy Audit

1. Discussion with operation, Electrical Maintenance, Mechanical Maintenance, C&I and Chemistry

2. Selection of equipments and instruments for power measurement for CW pumps & CT fans

3. Data collection based on power measurement, DBT / WBT measurement for cooling performance, UCB data collection for heat load calculation

4. Analysis of data

5. Calculation of performance to determine key indicators for assessing the performance of various systems.

Contd..

3.3 Preparations for Audit

Selection of appropriate time for conducting audit.

Selection of units for audit.

Selection of equipments & instruments for measurement.

Calibration of instruments for pressure & temperature measurement in DAS.

Assistance from O & M personnel.

Design / rated parameters from technical operating manuals, equipments name plates, etc.

3.4 DESIGN DATA COLLECTION

3.4.1DESIGN DATA – CONDENSER

S. S. NONO

DESCRIPTIONDESCRIPTION DATADATA

1.1. Tube MaterialTube Material

2.2. Tube Outside dia (mm)Tube Outside dia (mm)

3.3. Tube Thickness (mm)Tube Thickness (mm)

4.4. Total Number of Tubes Total Number of Tubes

5.5. Tube Length (Meters)Tube Length (Meters)

6.6. No. of Plugged Tubes No. of Plugged Tubes

7.7. No. of PassesNo. of Passes

8.8. Design Surface Area (SQM)Design Surface Area (SQM)

3.4.2DESIGN DATA – STEAM SIDE9.9. Back Pressure (kg / sq. cm)Back Pressure (kg / sq. cm)

10.10. Condenser Duty Condenser Duty

3.4.3DESIGN DATA – WATER SIDE

S. S. NONO


11.11. Cooling Water FlowCooling Water Flow

12.12. CW Inlet TemperatureCW Inlet Temperature

13.13. CW Outlet TemperatureCW Outlet Temperature

14.14. Design Water VelocityDesign Water Velocity

15.15. CW Pressure DropCW Pressure Drop

16.16. CW SourceCW Source

17.17. Design Cleanliness Factor Design Cleanliness Factor

3.4.4DESIGN DATA – GENERATOR

S. S. NONO


18.18. Design Heat Rate kCal / kWh at ….. Design Heat Rate kCal / kWh at ….. MWMW

19.19. Gross Power Generated MW Gross Power Generated MW

3.4.5WATER CHEMISTRY - DESIGN VALUES

S. S. NONO


1.1. PH at 25PH at 2500CC

2.2. ConductivityConductivity

3.3. T.D.ST.D.S

4.4. Total hardness Total hardness

5.5. Calcium HardnessCalcium Hardness

6.6. Magnesium HardnessMagnesium Hardness

7.7. P-AlkalinityP-Alkalinity

8.8. M-alkalinityM-alkalinity

9.9. ChlorideChloride

10.10. SulphateSulphate

11.11. Cycle of ConcentrationCycle of Concentration

12.12. L.S.IL.S.I

3.5 Equipments & Measurements The following instruments are typically used for measuring various parameters in the context of energy audit of CW, CT & Condenser performance.

Intake air DBT & WBT at each cell (ground Intake air DBT & WBT at each cell (ground level)level)

PsychrometerPsychrometer

CW inlet temperature common) (risers or CT CW inlet temperature common) (risers or CT top)top)

Hg in glass thermometerHg in glass thermometer

CW outlet temperature (common) (fills CW outlet temperature (common) (fills bottom)bottom)

Hg in glass thermometerHg in glass thermometer

CW sump / basin temperature (overall)CW sump / basin temperature (overall) - Do - - Do -

UCB Data : MW load, frequency, condenser, UCB Data : MW load, frequency, condenser, inlet / outlet temperature, condenser inlet / outlet temperature, condenser vacuum, extraction steam flow from heaters, vacuum, extraction steam flow from heaters, etc.etc.

DASDAS

CW pump elect. Data : Motor amps, volts, CW pump elect. Data : Motor amps, volts, power factor, kilo wattpower factor, kilo watt

Measurement by power Measurement by power analyseranalyser

CT pump house fore-bay level CT pump house fore-bay level CW pump readings for TDHCW pump readings for TDH

Physically measuredPhysically measured

CT fans : AmpsCT fans : AmpsCT transformer – Amp., Volts, PF, kWCT transformer – Amp., Volts, PF, kW

Tong tester Tong tester Power analyserPower analyser

Lab analysis data of CW (inlet), OAC and Lab analysis data of CW (inlet), OAC and makeup water makeup water

Lab water analysis Lab water analysis

3.6 AUDIT DATA COLLECTION

The following parameters are typically chosen for spot observations.

1. UCB Parameters : MW load, frequency, main steam flow, extraction steam flow for various heaters, LPT exhaust steam flow, steam temperatures & pressures, condenser vacuum etc., for calculation of condenser heat load & CW flow.

2. ELECTRICAL Parameters : Measurement of voltage, power factor & kW for CW pumps, CT transformer & CT fans.

3. MECHANICAL Parameters CW PUMPS : Measuring data for TDH of CW pumps and Fore bay level.

4. CHEMICAL / THERMAL Parameters : Measurement of DBT / WBT of air at cooling tower, CT basin water temperature, CW quality I.e., TDS & COC for CT performance & CW system water consumption.

SAMPLE DATA SHEET – 1

S. S. NoNo..

ParametersParameters UnitUnit Design Design ValueValue

Unit DataUnit Data

1.1. Unit LoadUnit Load MWMW 210.0210.0 211.0211.0

2.2. FrequencyFrequency HzHz 50.050.0 51.251.2

3.3. M.S. TemperatureM.S. Temperature 00CC 535.0535.0 530.0530.0

4.4. M.S. Flow M.S. Flow T/Hr.T/Hr. 651.3651.3 730.0730.0

5.5. HRH Pr.HRH Pr. Kg/Sq. CmKg/Sq. Cm 24.824.8 24.524.5

6.6. HRH TemperatureHRH Temperature 00CC 535.0535.0 535.0535.0

7.7. CRH Pr.CRH Pr. Kg/sq. CmKg/sq. Cm 28.828.8 30.330.3

8.8. CRH Temperature CRH Temperature 00CC 328.0328.0 324.0324.0

9.9. Feed Water Flow Feed Water Flow T/Hr. T/Hr. 651.3651.3 689.0689.0

1010 F.W. Temperature at Inlet of F.W. Temperature at Inlet of

HPH 5HPH 5 00CC 167.0167.0 164.0164.0

HPH 6HPH 6 00CC 182.0182.0 185.0185.0

HPH 7HPH 7 00CC 225.0225.0 220.0220.0

11.11. F.W. temperature at outlet of F.W. temperature at outlet of

HPH 5HPH 5 00CC 182.0182.0 185.0185.0

HPH 6HPH 6 00CC 225.0225.0 220.0220.0

HPH 7HPH 7 00CC 248.0248.0 257.1257.1Contd..Contd..

SAMPLE DATA SHEET – 1 Contd..

S. S. NoNo..


Unit DataUnit Data

12.12. Drip Temperature from Drip Temperature from

HPH 5HPH 5 00CC 177.0177.0 171.8171.8

HPH 6HPH 6 00CC 192.0192.0 202.6202.6

HPH 7HPH 7 00CC 235.0235.0 236.1236.1

13.13. Ex. Steam temperature at inlet to Ex. Steam temperature at inlet to

HPH 5HPH 5 00CC 440.0440.0 455.9455.9

HPH 6HPH 6 00CC 328.0328.0 323.7323.7

HPH 7HPH 7 00CC 378.0378.0 415.5415.5

14.14. Ex. Steam pressure at inlet to Ex. Steam pressure at inlet to

HPH 5HPH 5 Kg / sq. cmKg / sq. cm 12.712.7 12.312.3



15.15. Condensate temperature at inlet of Condensate temperature at inlet of

LPH 1LPH 1 00CC 44.044.0 58.058.0

LPH 2LPH 2 00CC 66.066.0 59.059.0

KPH 3KPH 3 00CC 105.0105.0 97.097.0

LPH 4LPH 4 00CC 127.0127.0 119.0119.0Contd..Contd..

SAMPLE DATA SHEET – 1 Contd…

S.NS.Noo

ParametersParameters UnitUnit Design ValueDesign Value Unit DataUnit Data

16.16. Condensate temperature at outlet of Condensate temperature at outlet of

LPH 1LPH 1 00CC 63.063.0 59.059.0

LPH 2LPH 2 00CC 105.0105.0 97.097.0

KPH 3KPH 3 00CC 127.0127.0 119.0119.0

LPH 4LPH 4 00CC 159.0159.0 156.0156.0

17.17. Drip temperature from Drip temperature from

LPH 1LPH 1 00CC 66.066.0 59.059.0

LPH 2LPH 2 00CC 102.0102.0 105.0105.0

KPH 3KPH 3 00CC 115.0115.0 117.0117.0

LPH 4LPH 4 00CC 150.0150.0 158.0158.0

18.18. Ex. Steam Temperature at inlet to Ex. Steam Temperature at inlet to

LPH 1LPH 1 00CC 95.095.0 97.097.0

LPH 2LPH 2 00CC 177.0177.0 169.0169.0

KPH 3KPH 3 00CC 252.0252.0 261.0261.0

LPH 4LPH 4 00CC 352.0352.0 388.0388.0

19.19. Ex. Steam pressure at inlet to Ex. Steam pressure at inlet to

LPH 1LPH 1 00CC 0.30.3 0.20.2

LPH 2LPH 2 00CC 1.51.5 1.81.8

KPH 3KPH 3 00CC 3.03.0 3.33.3

LPH 4LPH 4 00CC 6.76.7 7.27.2

S.NS.Noo

ParametersParameters UnitUnit Design ValueDesign Value Unit DataUnit Data

20.20. CW inlet temperature CW inlet temperature 00CC 30.030.0 32.532.5

Pass – APass – A 00CC 30.030.0 32.632.6

Pass – B Pass – B 00CC 30.030.0 32.432.4

21.21. CW outlet temperature CW outlet temperature 00CC 38.438.4 44.244.2

Pass – A Pass – A 00CC 38.438.4 44.244.2

Pass – B Pass – B 00CC 38.438.4 44.144.1

22.22. LPT exhaust temperature LPT exhaust temperature 00CC 43.243.2 50.450.4

Pass – APass – A 00CC 43.243.2 50.850.8

Pass – B Pass – B 00CC 43.243.2 50.050.0

23.23. CEP suction temperature CEP suction temperature 00CC 43.043.0 48.948.9

24.24. Condenser vacuum (as per DAS)Condenser vacuum (as per DAS) Kg/Sq Cm.Kg/Sq Cm. 0.9110.911 0.8710.871

25.25. Con. Vac (Kinetometer) Con. Vac (Kinetometer) Cm Hg.Cm Hg. 66.9566.95 64.6064.60

Con. Vac (Kinetometer) Con. Vac (Kinetometer) Kg/Sq. CmKg/Sq. Cm 0.9110.911 0.8790.879

Con. Vac (as per LPT exhaust)Con. Vac (as per LPT exhaust) Kg/Sq. CmKg/Sq. Cm 0.9110.911 0.8720.872

26.26. Air / Steam mixture temp. (Ejec-A)Air / Steam mixture temp. (Ejec-A) 00CC 46.046.0

Air / Steam mixture temp. (Ejec-B)Air / Steam mixture temp. (Ejec-B) 00CC 42.042.0

27.27. Ejector steam pressure Ejector steam pressure Kg/Sq. CmKg/Sq. Cm 19.1919.19

28.28. CW pressure at condenser inlet CW pressure at condenser inlet Kg/Sq. CmKg/Sq. Cm N/AN/A

29.29. CW pressure at condenser outlet CW pressure at condenser outlet Kg/Sq. CmKg/Sq. Cm N/AN/A

CW pressure drop across cond. CW pressure drop across cond. TubesTubes

Kg/Sq. CmKg/Sq. Cm 0.3700.370 ----

30.30. Condensate flow (design)Condensate flow (design) T/Hr.T/Hr. 471.2471.2 471.2471.2

SAMPLE DATA SHEET – 1 Contd…

SAMPLE DATA SHEET – 2

CT FAN DUTYItem Ref.Item Ref. UnitUnit

ssDesigDesig

nnFan- Fan-

AAFanFan- B- B

Fan-Fan-CC

Fan-Fan-DD

Fan- Fan- EE

Fan- Fan- FF

FanFan-G-G

FanFan-H-H

FanFan-I-I

SuSumm

Voltage Voltage (measured(measured))

VV 415415 418418 418418 418418 418418 418418 418418 418418 418418 418418

Current Current (measured(measured))

AA 113113 9090 8888 9898 00 8585 8888 9090 8585 9090 714714

Motor Motor power power factorfactor

0.8970.897 0.8970.897 0.8970.897 0.8970.897 0.8970.897 0.8970.897 0.8970.897 0.890.8977

0.8970.897

Motor Motor efficiency efficiency (Ref.)(Ref.)

0.90.9 0.90.9 0.90.9 0.90.9 0.90.9 0.90.9 0.90.9 0.90.9

Fan input Fan input power power

kWkW 6767 52.6052.60 51.4351.43 57.2757.27 49.6749.67 51.4351.43 52.6052.60 49.649.677

52.6052.60 52.1652.16

CT fan air CT fan air flow flow 10001000

Kg / Kg / hrhr

26542654 24482448 24302430 25192519 24022402 24302430 24482448 24022402 24482448 1952195288

SAMPLE DATA SHEET – 3 CHEMICAL DATA FOR CIRCULATING WATER

MonthMonth TDS TDS ppmppm

NaNappmppm

COCCOC pHpH TurbidityTurbidityNTUNTU

March March 150150 9.89.8 1.51.5 8.38.3 2222

April April 174174 11.511.5 1.641.64 8.318.31 8.58.5

May May 161161 11.511.5 1.551.55 8.488.48 13.013.0

S.NS.Noo

Quality of WaterQuality of Water Effect of QualityEffect of Quality

1.1. Low COC = 1.6 to Low COC = 1.6 to 1.81.8

Less corrosive effectLess corrosive effect

2.2. High COC > 2.0High COC > 2.0 Scale deposition increasesScale deposition increases

3.3. Acidic pHAcidic pH Very corrosiveVery corrosive

4.4. pH > 8.5pH > 8.5 [[AA]. Copper pick increases]. Copper pick increasesMaterial of Condenser tube = Material of Condenser tube = Cu Cu 95 % 95 % Ni Ni 5 %5 %

[[BB] Chlorine effect reduces ] Chlorine effect reduces

5.5. COC V. Low = < 1.3COC V. Low = < 1.3 No scale deposition (because less TDS in CW No scale deposition (because less TDS in CW system); but metal pick increases fastsystem); but metal pick increases fast

6.6. TurbidityTurbidity MU water turbidity = 20 NTU (make-up water) MU water turbidity = 20 NTU (make-up water)

7.7. TDS Values TDS Values Raw MU Water TDS = 100 / 110 PPMRaw MU Water TDS = 100 / 110 PPMAC water TDS = 160 / 180 PPM AC water TDS = 160 / 180 PPM

FORMULAE USED FOR CALCULATIONS - A

1. Condenser heat load calculation :

The following data is required for heat load calculation :

Contd..

a) LPT exhaust flow

b) Enthalpy of exhaust steam

c) Enthalpy of condensate

a) LPT exhaust flow

= [Main steam flow – Extraction steam flow – Aux. Steam flow – D/A steam flow – ESV leak-off – Seals leakage]

FORMULAE USED FOR CALCULATIONS - A

Extraction steam flow is calculated by heat balance i.e.,

Condenser heat load

= [ LPT exh. Steam enthalpy – Condensate enthalpy] Exhaust Steam flow rate

etemperatur Dripsteamexhaust ofEnthalpy

temp.O/L FW - temp.I/L (FW flowWater Feed Flow Steam Extraction

CW flow can be calculated by heat balance

C)0( rise etemperatur CWHr.) / Cal (k loadheat Condenser Flow CW

FORMULAE USED FOR CALCULATIONS - B

2. CW flow calculation as per power measurement :

Power input to pump = Motor efficiency Power input to motor

LKW = Pump efficiency Motor efficiency Power input to motor

Actual CW flow thro’ condenser = less than 100 % of CW discharge flow as

Part of CW flow is often used for cooling purposes in turbine side boiler side, ash slurry, etc.

. Hr / 3M9.81 TDH3600 LkW flow discharge pump CW

kW 1000

PF I V 3 motor toinput Power

FORMULAE USED FOR CALCULATION - C

3. CT fan air flow calculation :

Power input to fans = Motor efficiency Power input to motor kW

Air flow per fan

CMH rated Fan 3

powerinput fan Ratedpowerinput Fan actual flowair Fan

kW 1000

PF I V 3 motor toinput Power

Contd..

wt.)(by cellper flow CW

wt.)(by cellper flow Air RatioG/L

/Hr.3M 675

Range CT Flow CT losses nEvaporatio

/Hr.3M 1 - COC

loss nEvaporatio water Makeup

4. COC is defined as the ratio of total dissolved solids in basin water to TDS in makeup water.

Water Consn. = (Evaporation Losses + Makeup water) M3/Hr.

CT Range = CW temp. at CT inlet – CW temp. at bottom fills

CT approach = CW temp. at CT outlet – WBT at ground level

FORMULAE USED FOR CALCULATION - D

100 Approach Range

Range esseffectiven CT %

% 100 WBT -Inlet CWT

Outlet CWT -Inlet CWT

SAMPLE CALCULATION SHEET FORCONDENSER HEAT LOAD CALCULATION

S. S. NoNo..


Unit DataUnit Data

1.1. Enthalpy of LPT exhaust steamEnthalpy of LPT exhaust steam kCal/kgkCal/kg 585.7585.7 619.3619.3

2.2. Enthalpy of condenser at CEP Enthalpy of condenser at CEP suction suction

kCal/kgkCal/kg 43.243.2 48.948.9

3.3. Enthalpy of ex. Steam at HPH 5 Enthalpy of ex. Steam at HPH 5 I/LI/L

kCal/kgkCal/kg 799.2799.2 807.4807.4


kCal/kgkCal/kg 733.0733.0 730.2730.2


kCal/kgkCal/kg 754.6754.6 776.4776.4

6.6. Enthalpy of ex. Steam at LPH 1 Enthalpy of ex. Steam at LPH 1 I/LI/L

kCal/kgkCal/kg 615.9615.9 640.1640.1


kCal/kgkCal/kg 675.4675.4 670.3670.3


kCal/kgkCal/kg 709.7709.7 713.4713.4


kCal/kgkCal/kg 756.9756.9 774.7774.7

Steam parameters at salient points :

Contd..

SAMPLE CALCULATION SHEET FORCONDENSER HEAT LOAD CALCULATION

S. S. No.No.


Unit DataUnit Data

1.1. Extraction steam flow at HPH 5Extraction steam flow at HPH 5 T/hr.T/hr. 16.416.4 22.822.8



4.4. Extraction steam flow at LPH 1Extraction steam flow at LPH 1 T/hr.T/hr. 16.616.6 0.80.8




8.8. Auxiliary steam flowAuxiliary steam flow T/hr.T/hr. 17.017.0 17.017.0

9.9. HPT seal leakageHPT seal leakage T/hr.T/hr. 12.012.0 12.012.0

10.10. HPT ESV leak offHPT ESV leak off T/hr.T/hr. 2.02.0 2.02.0

11.11. Ext. to deaeratorExt. to deaerator T/hr.T/hr. 4.04.0 4.04.0

12.12. LPT exhaust flow (calculated)LPT exhaust flow (calculated) T/hr.T/hr. 436.7436.7 501.1501.1

13.13. Av. CW temperature riseAv. CW temperature rise 00CC 8.48.4 11.711.7

14.14. Condenser heat loadCondenser heat load kCal/kgkCal/kg 542.5542.5 570.4570.4

15.15. Condenser heat load Condenser heat load 1000 1000 kCal/kgkCal/kg 236910236910 285831285831

16.16. CW flow (CMH) CW Flow = (Heat load CW flow (CMH) CW Flow = (Heat load / CW Temperature difference)/ CW Temperature difference)

T/hr.T/hr. 28203.528203.5 24534.824534.8

Steam parameters at salient points :

SAMPLE CW PUMP DUTY ASSESSMENT

S. S. No.No.

Item ReferenceItem Reference UnitUnit Design Design ValueValue

Unit Unit DataData

1.1. Fore bay levelFore bay level MSLMSL

21.8 – 21.8 – 22.622.6

279.4279.4

2.2. Fore bay to floorFore bay to floor mWCmWC 4.254.25

3.3. Bowl loss (Reference)Bowl loss (Reference) mWCmWC 0.200.20

4.4. Height of pressure gaugeHeight of pressure gauge mWCmWC 1.331.33

5.5. Discharge pressureDischarge pressure mWCmWC 22.0022.00

6.6. Velocity head @ 1.89 m/sVelocity head @ 1.89 m/s mWCmWC 0.180.18

7.7. Total differential head Total differential head mWCmWC 27.9627.96

Total diff. Head calculation :

SAMPLE FLOW BALANCE OF CW PUMP BY MOTOR LOADING

S. S. No.No.

Item ReferenceItem Reference UnitUnit Design Design ValueValue

Unit DataUnit Data

Pump-APump-A Pump-BPump-B

1.1. Voltage (measured)Voltage (measured) VV 66006600 66816681 65026502

2.2. Current (measured)Current (measured) AA 205205 173.98173.98 175.43175.43

3.3. Power factor (measured)Power factor (measured) -- 0.850.85 0.64180.6418 0.6750.675

4.4. Power input to motorPower input to motor kWkW 20002000 12921292 13341334

5.5. Power input to pump Power input to pump (@ 94.5% motor efficiency) (@ 94.5% motor efficiency)

kWkW 12211221 12601260

6.6. Average pump input powerAverage pump input power kWkW 12411241

7.7. LKW (@ 87 % pump efficiency)LKW (@ 87 % pump efficiency) 2 2 1130 1130 21592159

8.8. Total CW discharge flowTotal CW discharge flow CMHCMH 3235032350 2833228332

9.9. Cooling water for Aux. (15 %)Cooling water for Aux. (15 %) CMHCMH 48504850 42504250

10.10. CW flow through condenser CW flow through condenser CMHCMH 2750027500 2408224082

11.11. CW taken for HP/LP pumpsCW taken for HP/LP pumps CMHCMH 410410 570570

12.12. CW going back to CTCW going back to CT CMHCMH 3000030000 2747927479

13.13. CW fans in serviceCW fans in service CMHCMH 88 88

14.14. CW flow per cell CW flow per cell CMHCMH 37503750 34353435

a) Power measurement by power analyser (Accuracy – Class-I (0.1 %)

b) CW flow calculation based on power measurement

SAMPLE CT FAN DUTY ASSESSMENT

S. S. No.No.

Item Reference Item Reference UnitUnit Design Design ValueValue

Unit Unit DataData

1.1. Voltage (measured)Voltage (measured) VV 66006600 65096509

2.2. Current (measured)Current (measured) AA 45.8645.86

3.3. Motor power factorMotor power factor ---- 0.89690.8969

4.4. Motor efficiency (Ref.)Motor efficiency (Ref.) ---- 0.90.9

5.5. CT Xmer input powerCT Xmer input power kWkW 603603 417.33417.33

6.6. Ct fan motor input power Ct fan motor input power kWkW 6767 52.1652.16

7.7. CT fan flow per tower CT fan flow per tower 10001000

Kg/hrKg/hr 2122921229 1953019530

8.8. Air flow per cell Air flow per cell 1000 1000 Kg/hr Kg/hr 26542654 24412441

Power Measurement by Power Analyser Accuracy Class-I (0.1 %)

SAMPLE CT PERFORMANCE ASSESSMENT

S. S. No.No. Item Reference Item Reference UnitUnit

Design Design ValueValue

Unit Unit DataData

1.1. Water inlet temperature to Water inlet temperature to CTCT

00CC 4343 4545

2.2. Water outlet temperature Water outlet temperature from CTfrom CT

00CC 3333 31.531.5

3.3. Wet Bulb temperature @ CT Wet Bulb temperature @ CT bottom bottom

00CC 28.428.4 24.524.5

4.4. Dry bulb temperature Dry bulb temperature ambient ambient

00CC ---- 3232

SAMPLE CT SYSTEM KEY INDICATORS

S. S. No.No.


Unit Unit DataData

1.1. CT rangeCT range 00CC 1010 13.513.5

2.2. CT approachCT approach 00CC 4.64.6 77

3.3. CT effectiveness CT effectiveness 0.6850.685 0.6590.659

4.4. Water / Air ratio (L/G Ratio)Water / Air ratio (L/G Ratio) 1.411.41 1.411.41

5.5. Air / Water Ratio (G/L Ratio)Air / Water Ratio (G/L Ratio) 0.710.71 0.710.71

6.6. Evaporation lossesEvaporation losses CMHCMH 444444 550550

7.7. TDSTDS PPMPPM 174174 174174

8.8. C.O.C.C.O.C. 2.502.50 1.641.64

9.9. Makeup waterMakeup water CMHCMH 296296 859859

10.10. Water consumptionWater consumption CMHCMH 741741 14081408

11.11. % water consumption % water consumption %% 2.292.29 4.974.97

SAMPLE OVERALL SYSTEM KEY INDICATORS

S. S. No.No.


Unit Unit DataData

1.1. Unit load Unit load MWMW 210210 211211

2.2. FrequencyFrequency HzHz 50.050.0 51.251.2

3.3. M.S. flowM.S. flow T/hrT/hr 651.3651.3 730730

4.4. F.W. flowF.W. flow T/hrT/hr 651.3651.3 689689

5.5. Total C.W. flowTotal C.W. flow T/hrT/hr 3235032350 2453524535

6.6. C.W. flow thru condenser C.W. flow thru condenser T/hrT/hr 2750027500 2453524535

7.7. Average CW temperature riseAverage CW temperature rise 00CC 8.48.4 11.711.7

8.8. Condenser heat loadCondenser heat load kCal/hr kCal/hr 10001000

236910236910 285831285831

9.9. Terminal temperature Terminal temperature differencedifference

00CC 4.84.8 6.26.2

10.10. LMTDLMTD 00CC 8.308.30 11.0411.04

11.11. Condenser vacuumCondenser vacuum Kg/sq.cmKg/sq.cm 0.9110.911 0.8710.871

12.12. CW pump pressure drop CW pump pressure drop (across condenser)(across condenser)

Meter Meter 3.703.70 Not Not MeasurabMeasurab

lele

ILLUSTRATIVE COMPARISON : CONDENSER VACUUM AND CW FLOW CHARACTERISTICS

Design Value Design Value Actual Steam Actual Steam Flow to Flow to

Condenser Condenser

Actual CW Actual CW Flow to Flow to

Condenser Condenser

Actual Actual CondensCondenser Heat er Heat Load Load

CondenseCondenser Vacuumr Vacuum

Exhaust Exhaust Hood Hood Steam Steam

Tempera-Tempera-ture ture

Case Case T / Hr.T / Hr. T / Hr.T / Hr. kCal/hrkCal/hr T / Hr.T / Hr. 00CC

1.1. ReferenceReference 436.7436.7 2820328203 236912369100100100

00

0.910.91 43.243.2

2.2. ReferenceReference 440440 2750027500 0.910.91 4444



5.5. ReferenceReference 500500 2500025000 0.90.9 46.146.1

ILLUSTRATIVE COMPARISON : CW PUMP PERFORMANCE

S. S. No.No.


Unit Unit DataData

1.1. Average CW pump motor Average CW pump motor inputinput

kWkW 13351335 13131313

2.2. Average CW pump LKWAverage CW pump LKW kWkW 11301130 1079.51079.5

3.3. CW discharge flow CW discharge flow (16175 CMH each Pump)(16175 CMH each Pump)

CMHCMH 3235032350 2833228332

4.4. CW flow thro’ condenserCW flow thro’ condenser CMHCMH 2750027500 2408224082

5.5. CW flow per cell CW flow per cell CMHCMH 37503750 34453445

6.6. CT fans on line CT fans on line Nos.Nos. 88 88

ILLUSTRATIVE COMPARISON : CT FAN PERFORMANCE

S. S. No.No.


Unit Unit DataData

1.1. Fan input power kWFan input power kW kWkW 6767 52.1752.17

2.2. CT fan air flow per towerCT fan air flow per tower Kg/hr Kg/hr 10001000

2122921229 1953019530

3.3. CT fan air flow per cell CT fan air flow per cell Kg/hr Kg/hr 10001000

26542654 24412441

4.4. CW flow per cellCW flow per cell Kg/hr Kg/hr 10001000

37503750 34453445

5.5. Water/Air ratio (L/G ratio)Water/Air ratio (L/G ratio) 1.411.41 1.411.41

Dry air density Dry air density

CT fans in operation CT fans in operation (for design performance)(for design performance)

Kg/MKg/M33

NoNo1.05551.0555

88

ILLUSTRATIVE COMPARISON : COOLING TOWER PERFORMANCE

HPHP KWKW CW FLOWCW FLOW 30,000 CMH30,000 CMH

FAN BHPFAN BHP 76.476.4 57.057.0Hot Water Temp.Hot Water Temp. 109.4 109.4

FF43 C43 C

MOTOR HPMOTOR HP 9090 67.167.1

Cold Water Temp.Cold Water Temp. 91.4 F91.4 F 33 F33 F

Fan air flow Fan air flow 21229 kg/hr 21229 kg/hr 1000 1000 Wet Bulb Temp.Wet Bulb Temp. 83.1 F83.1 F 28.4 C28.4 C

CT fans in CT fans in operationoperation

8 Nos.8 Nos. 22 F22 F 12.2 C12.2 C

CT air flow / CT air flow / cell cell

2654 kg/hr 2654 kg/hr 1000 1000 18 F18 F 10 C10 C

14 F14 F 7.8 C7.8 C

DESIGN DATA

Contd..

ILLUSTRATIVE COMPARISON : COOLING TOWER PERFORMANCE

DESIGN DATA

Item Reference Item Reference UnitsUnits Unit Unit

DataData

CT RangeCT Range 00CC 13.513.5

Wet bulb temperature Wet bulb temperature (measured)(measured)

00CC 24.524.5

Cold water temperature Cold water temperature (measured)(measured)

00CC 76.1 F76.1 F

31.531.5

Cold water temperature Cold water temperature (design)(design)

00CC 32.532.5

ILLUSTRATIVE COMPARISON :COOLING TOWER PERFORMANCE

S. S. NoNo..

Item Reference Item Reference Design Design ValueValue

Unit Unit DataData

A.A. By process parametersBy process parameters 2820328203 2453524535

B.B. By CW pump motor By CW pump motor loadingloading

2750027500 2408224082

C.C. By LMTD calculation By LMTD calculation 2872828728 2400024000

CW FLOW (M3 / Hr)

SAMPLE SCAN OF CW PUMPS – ENERGY AUDIT OBSERVATIONS

Eqpt. Eqpt. Ref.Ref.

kW DrawnkW Drawn FlowFlow Pressure (kg/cm2) Pumps (mmWc) for FansPressure (kg/cm2) Pumps (mmWc) for Fans Liquid kWLiquid kWof Air kWof Air kW

CombinedCombinedEfficiency (%)Efficiency (%)

S.C.ES.C.E(kWh/Ton)(kWh/Ton) Motor Motor

LoadiLoading %ng %

UnitUnit

KwKw TPHTPH Suction*Suction* DischargeDischarge DifferentialDifferential Gen. Gen. (MW)(MW)

Freq. Freq. (Hz)(Hz)

DesigDesignn

ActuaActuall

DesignDesign ActualActual DesiDesigngn

ActuActualal

DesigDesignn

ActuaActuall

DesiDesigngn

ActuaActuall

DesigDesignn

ActuaActuall

DesigDesignn

ActuaActuall

DesigDesignn

ActualActual

CWP – CWP – 11

13771377 10211021 1500015000 1329513295 00 00 2.52.5 1.901.90 2.52.5 1.901.90 10211021 688.688.33

74.174.188

67.467.433

0.090.0922

0.0760.07688

74.274.244

189.189.66

47.947.911

CWP – CWP – 22

13771377 10141014 1500015000 1327413274 00 00 2.52.5 1.901.90 2.52.5 1.901.90 10211021 687.687.22

74.174.188

67.767.766

0.090.0922

0.0760.07644

73.773.788

186.186.22

47.847.855

CWP – CWP – 33

13771377 10181018 1500015000 1342213422 00 00 2.52.5 1.901.90 2.52.5 1.901.90 10211021 694.694.99

74.174.188

68.268.233

0.090.0922

0.0750.07599

74.074.077

191.191.66

48.348.366

CWP – CWP – 44

13771377 10781078 1500015000 1331013310 00 00 2.52.5 1.751.75 2.52.5 1.751.75 10211021 634.634.77

74.174.188

58.858.899

0.090.0922

0.0810.08100

78.378.399

193.193.99

48.248.200

CWP – CWP – 55

13771377 983983 1500015000 1315913159 00 00 2.52.5 1.851.85 2.52.5 1.851.85 10211021 663.663.44

74.174.188

67.567.500

0.090.0922

0.0740.07477

71.471.477

194.194.55

47.847.811

CWP – CWP – 66

13771377 11041104 1500015000 1319713197 00 00 2.52.5 1.801.80 2.52.5 1.801.80 10211021 647.647.33

74.174.188

68.668.644

0.090.0922

0.0830.08388

80.280.288

194.194.11

47.947.900

CWP – CWP – 77

13771377 11431143 1500015000 1318313183 00 00 2.52.5 1.951.95 2.52.5 1.951.95 10211021 700.700.55

74.174.188

61.361.311

0.090.0922

0.0860.08677

83.083.099

194.194.77

47.847.844

CONCLUSIONS

The audit conclusions are site specific and situation specific. The menu of recommendations substantiated adequately are most likely to include ; Timely descaling of condensers

Ensuring adequacy of CW flow through condensers

Improving operational energy efficiency of CW pumps by maintenance or retrofit or replacement options

Tuning of CT operations for achieving best CT range, L/G ratio, approach for given loading, ambient conditions.

Water quality improvements and design COC improvements.

Debottlenecking of any O & M constraints

Fill replacement/replenishment in cooling towers

Improvements in instrumentation and MIS for enabling continuous efforts by O & M and O & E teams.

Date post:	26-May-2015
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Ea of cw, ct & cond. system

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