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ANSH ENERGY SOLUTIONS PVT. LTD.admin@anshenergy.com

COMPREHENSIVE ENERGY AUDIT REPORT of 6.6 MW COGENRATION THERMAL CAPTIVE POWER PLANT

CLIENT: M/S Magnum Ventures Ltd., Shaibabad

June, 2010

Audit conducted by:

ANSH ENERGY SOLUTIONS PVT. LTD., Gayatri Dham, Lower Bazar, Modinagar – 201204 (UP)

Auditor BEE Registration: EA-10465 (Anubhav Gupta) & EA-

3267(Anshul Singh Yadav)

Report No. AESPL/10-11/AG/12

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Contents Acknowledgement ii Audit firm and Audit Team Details iii List of Abbreviations iv Executive Summary v

Chapter 2: INTRODUCTION TO ENERGY AUDIT AND METHODOLOGY 1

2.1. Audit Objective and purpose of Energy Audit 1 2.2. Scope of Work 1 2.3. Methodology and approach followed 1 2.4. Time Schedule for Conducting the energy audit 2 2.5. Details of the Instruments used 2 2.6. Description of the Plant 2 2.7. Energy Consumption Profile and Energy Management System 3 2.8. Equipment and Major Areas for Energy Audit 5 2.10. List References 6

Chapter 3: Boiler

3.1 BACKGROUND 7 3.2 Operational efficiency of the boiler 7 3.3 Blow down losses 10 3.4 Blow Down Rate Estimation 10 3.5 Boiler Water Treatment 14 3.6 Boiler blow down heat recovery applications 14 3.7 Energy Saving by Flash steam recovery3.8 Energy Saving by Flue gas heat impingement on feed stock conveyor 3.9 Energy Saving by re‐insulation of damaged areas

16 17 18

Chapter 4: Water Pumping 19

4.1 Background 19 4.2 Energy consumption pattern for pumps: 19 4.3 Observations & Recommendations 20

Chapter 5: Turbine 22

5.1 Background 22 5.2 Turbine Efficiency evaluation 22 5.3 Effect of Steam inlet pressure 24 5.4 Effect of Steam inlet temperature 25 5.5 Effect of exhaust pressure/ vacuum 26

Chapter 6: Condenser Cooling 28

6.1 Background 28 6.2 Cooling Tower 28 6.3 Observations 29 6.4 Conclusion Recommendation 30

Chapter 7: Electrical Systems and Motors 32

7.1 Background 32 7.2 Transformers 32 7.3 Power Factor Analysis 33 7.4 Loading pattern of motors 34 7.5 Motor Efficiency Calculation 36 7.6 Harmonic Measurement 38 7.1 Power Supply Quality 40

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Investment Grade Energy Audit has been done with the objectives to identify & quantify the energy saving opportunities for 6.6MW Cogeneration Captive Thermal Power Plant of M/S Magnum Ventures Ltd., Shaibabad, Uttar Pradesh. We would like to thank Shri Pradeep Jain, MD, Magnum Ventures Ltd., Mr. Ritesh Jain for their giving us this opportunity and continuous support and encouragement during the course of Energy Audit. We also the commitment of Shri Pradeep Jain and his team towards cost reduction and energy conservation for betterment of the company and the environment. We extend our gratitude towards Mr. Anil Bana, Head Power Plant, and entire power plant team for their steadfast support extended to us during this study. We would like to convey our special thanks to field staff for their inputs.

Energy Audit Team Anubhav Gupta

Anshul Singh Yadav Vikram Pal Singh

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Audit Firm and Audit Team Details

Ansh Energy Solutions Pvt. Ltd. is energy efficiency consultancy and practice areas are project feasibility, DPR preparation, Impact assessment studies, monitoring and verification assignments as independent evaluators, energy Audits, analyze the energy consumption and evaluate cost effective opportunities to save electricity and fuels. We also undertake advisory services for industries related to environmental aspects and works in the areas of Green Buildings, Climate change activities and Sustainable development.

Ansh Energy Solutions Pvt. Ltd. is a professionally managed company with a team of full time engineering professionals and Energy Auditors who are available to help and address clients specific utility needs. Ansh Energy Solutions Pvt. Ltd. advices its clients on energy efficiency and energy conservation plans, which are of paramount importance to them. The areas of our expertise in this regard are:

a) Energy Audit

b) End Use Efficiency Improvement Programmes

c) Monitoring & Verification (M&V)

d) Energy Conservation Management plan

Audit Team

Anubhav Gupta, Director Ansh Energy Solutions Pvt. Ltd. Certified Energy Auditor from BEE having experience of umpteen project implementations including, manufacturing facility setup, power plant setups, refurbishing building envelopes, organization and coordination of various BEE seminars and workshops. By qualification a Chemical Engineer from IT‐BHU, MBA in Sales and Marketing and a certified Six Sigma Black belt he brings and all round experience of industry, institutions and academics together in one place.

Anshul Singh Yadav Mechanical Engineer by basic qualification and MBA from the Management Development Institute (MDI), Gurgaon, Certified B.O.E (Boiler Operation Engineer First class proficiency) having over 12 years of hands on experience in in O&M of Power Plants and other utilities. Power sector experience, spans in the diverse aspects of energy business from Plant operations management, Maintenance planning, Fuel management and Strategic Planning, Plant Commissioning, etc.

Vikram Pal Singh (PGDBM, BSc., DEE) is having 7 years of experience in energy audits, energy efficiency projects, project management and training. His area of interest is green buildings and CDM linked funding mechanism for Small size green projects.

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Abbreviations ACs Air Conditioners

BEE Bureau of Energy Efficiency

CT Cooling Tower

ECO Energy Conservation Opportunity

EMP Energy Management Plan

M3/hr Cubic Meter Per Hours

FTL Fluorescent Tube Light Lamp

HPSV High Pressure Sodium Vapour

KVA Kilo Volt Ampere

KWH Kilowatt Hour

KVAH Kilo Volt Amperes Hour

KVAr Kilo Volt Amperes Reactive

KW Kilo Watt

LPD Litres Per Day

MW Mega Watt

O&M Operation and Maintenance

P.F Power Factor

PV Photo Voltaic

SPC Specific Power Consumption

STC Standard Test Condition

SWH Solar Water Heater

SQ. M. Square Meter

TR Ton of Refrigeration

V Volt

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1.1. Brief Company Profile: Magnum Ventures Ltd, one of the largest paper manufacturing

mills of Northern India having installed capacity of 85000 TPA. This includes equal quantity of Cream wove Paper, Maplitho, Copier, and Coated Duplex Board. The Company is having large infrastructures 65000 Square Meter and Five Lacs Square feet Building Area in Sahibabad Industrial Area, Ghaziabad (U.P.). This energy audit study was carried out for 6.6MW thermal captive power plant of paper mill. This power plant was commissioned in the year 2004 as 4.4 MW unit and expanded to 6.6 MW in year 2008.

Power Plant comprises of 31 Tph, Thermax make, Bi‐drum, natural circulation, under bed, balanced draft, atmospheric fluidisation bed combustion, bottom supported, and membrane wall construction type of a boiler. Two sets of Trevani make turbo generator with 1st Turbine is of 4.4 Mw extraction cum condensing type and 2nd Turbine is of 2.2Mw condensing Type and other power plant auxiliary and power distribution system.

1.2. Scope of the audit study: The main objective of this exercise is to carry out specific energy

consumption analysis and make recommendations for reduction in auxiliary power, optimize specific fuel consumption and to achieve a reduction in recurring expenditure on energy to improve business viability by plugging the waste energy and through improvement in the operational and maintenance practices of the facility. Major areas covered under energy audit study of the Power Plant were Boiler and its auxiliaries, water pumping system, cooling towers, motors and electrical distribution system.

1.3. Time Schedule for Conducting the energy audit

Field study – 4th June 2010 to 11th June 2010

Report Preparation – 12th June to 30th June

1.4. Energy Consumption and Energy Generation of the Plant: The average daily power production is 1,30,000 units and monthly power production average is of 39lacs unit of Power out of which 33.87lacs of unit is supplied to paper plant and rest 4.84 lac units per month is the Auxiliary Power Consumption, break‐up of this auxiliary power is graphically represented in following chart.

Figure: Share of different equipments in Auxiliary Power Consumption

59%25%

11%5%

Auxiliary Power ComponentsPumps Boiler Auxiliary CT Fan Others

1. EXECUTIVE SUMMARY

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The major part of this auxiliary power is being consumed by water pumping system, followed by Boiler auxiliaries like FD Fan, ID Fan, PA Fan and Coal handling system and Coal mill, around 11% of the auxiliary power is being consumed by cooling tower fans and rest 5% is consumed by remaining equipments and lighting load.

Table: Monthly Fuel Consumption, Steam & Power Production and Supply position Month FEB March April May

Total Coal Consumption in Ton 6368 6200 6238 4969

Cost of Coal (in Rs.) 2,54,62,199 2,61,71,530 2,57,54,803 2,41,85,169

Total Steam Generation (in Ton) 25,103 25,283 24,994 26,169

Steam supply to Plant (in Ton) 13,236 13,353 13,067 13,141

Total Power Generated (KWh) 37,59,000 38,54,500 38,28,000 40,45,000

Power Supply to Plant (Kwh) 33,39,000 34,04,000 33,18,000 34,87,000

Fuel Cost per unit of Power (Rs/Kwh) 6.77 6.79 6.73 5.98

Cost of steam (in Rs/ton) 1014.31 1035.14 1030.44 924.19

Aux Power Consumption Kwh 420,000 450,500 510,000 558,000

Aux Power Consumption Ratio % 8.95 8.56 7.51 7.25

Summary of the Baseline Energy Consumption 1 Average annual electricity production 4,64,59,500 kWh2 Average annual electricity supply to main Plant 4,06,44,000KWh3 Average annual auxiliary power consumption 58,15,500KWh4 Average annual steam generation 3,04,647Ton5 Average Auxiliary Power consumption ratio 8.07%6 Average annual Coal consumption for co‐generation 71325ton7 Average heat rate of 4.4 MW turbine 4700Kcal/kg8 Average heat rate of 2.2 MW turbine 2800Kcal/kg9 Average Boiler Efficiency 80%10 Average turbine cycle efficiency 4.4Mw 18.3%11 Average turbine cycle efficiency 2.2Mw 30.2%

1.5. Major observations:

Boilers The method of performance assessment chosen for Boiler performance test is the indirect method of heat loss and boiler efficiency as per BIS standard 8753. The test method employed is based on abbreviated efficiency by loss method (or indirect method) tests, which neglects the minor losses and heat credits.

The Boiler efficiency is observed as 80.91% against the 83 ±2% design efficiency, there is a margin of about 2‐3% improvement by various measures, which are largely O&E related and R&M related. About 1‐2% improvement is possible by various O&E related aspects such as providing improved insulation at furnace, APH, Economiser, manhole doors and by providing internal lining of fire proof cement on furnace doors. For further improvement in efficiency, R&M activities are required especially in the area of super heater so that design parameters of super heated steam can be

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achieved; in this regard detail techno economic and cost benefit analysis is being carried out in chapter on turbines.

Overall boiler water, CBD & Steam water quality & chemistry is observed within the prescribed limit of OEM, however it was observed that parameters like O2, residual hydrazine, metal contents like copper and iron and conductivity are not being monitored on regular basis.

CBD flow rate is observed in the range of 600‐900Liters/hr at temperature of 170 °C leaving scope for heat recovery through flash steam recovery system.

Observed loss due to moisture in fuel is 0.86 % which can be brought down to a value of 0.20% detail is discussed in 3.8 sections.

Water Pumping System Water pumping is vital energy consuming area in the power plant. Major pumps which were studied in this report are:

Condensate Extraction pumps Boiler feed water pumps RO/DM water plant pumps

Make‐up/transfer pump Cooling water circulation pumps Raw water pumps

Total approximate energy consumption of pumping system = 10754 Kwh per day

Total auxiliary power consumption per day = 16200Kwh

Almost two third of the auxiliary power is consumed by water pumping system.

From the pump performance analysis based on the actual operating parameters we have observed efficiency of 4.4MW turbine condenser cooling water pumps less than 60% which is on lower side.

There is no energy and flow meters installed for major pumps in the power plant

Turbine

The average heat rate of 4.4 MW turbine is observed as 4700Kcal/kg and for 2.2MW turbine is 2800Kcal/kg with turbine cycle efficiency of 18.3% and 30.2% respectively. In absence of performance GTR data it is difficult to identify deviation from that. It is also observed that steam generated in the boiler is of specification 65kg/cm2 and Temperature 445°C against the design temperature of 490°C ±5°C. An increase in inlet steam temperature, i.e., an increase in superheat at constant inlet pressure and condenser pressure gives a steady improvement in cycle efficiency and lowers the heat rate due to the increase in inlet temp and rising the inlet temperature also reduces the wetness of the steam in later section of the turbine and improves internal efficiency of the turbine.

If the turbine inlet steam temperature is increased to 490°C ±5°C as per the design conditions then the heat energy input to the turbine will be increased and corresponding effect in cycle efficiency is achieved @ 5.5% to 6.5% reduction in specific steam consumption for same amount of power generated and turbine efficiency will improve by of 0.6% to 0.72%.

Cooling Tower

CT ‐1 range found to be 7.9 and CT‐2 range found to be 11.6 against design of 8 CT‐1&2 approach found to be 10.73 and 8.8 against design 4 indicates, poor heat transfer. CT‐1 &2, effectiveness found to be 42.40% and 56.86% against design 66.66%, which indicates poor heat transfer in CT.

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Power measurements indicate under loading on CT fan motors and power factor is in the range of 0.52 to 0.74. This is poor.

In Cooling Tower ‐1, Fly ash & other foreign particles are presented in reasonable quantity at most of the places like lowers, frills etc.

As per the water quality concerned, makeup water quality is very good, here the scaling chances in the system are very less but corrosion is taking place aggressively specially in MS pipelines.

At some places in cooling water piping system corrosion observed due to which water leakage/seepage is existing.

The corrosion in the system is suspected due to improper functioning of corrosion inhibitor treatment. As PH in circulating water is around 8.5, Zn as corrosion inhibitor will not work perfectly at higher PH. As Zinc will precipitate at higher PH & not inhibit the surfaces perfectly.

Alkalinity in the makeup water is very less; treatment philosophy must be designed to take care of low alkalinity system to control corrosion.

Electrical system and motors

There is no sub metering of the transformers and major equipments.

The cumulative transformation capacity is 8500 KVA for 4300 MW (5625 KVA) Alternator.

The earthing pits for transformer are not adequately spaced.

The overall power factor of the plant is being maintained at above 0.93 lagging, but the power factor of some of the individual feeders is below the satisfactory level.

The motors of Main elevator 1&2, Reject elevator 1, Ash Handling Motor, and all cooling tower fans are operating at less than 60% of loading.

The average total voltage harmonic distortion is 6.45%.

The average total current harmonic distortion is 9.3%.

The variation between the terminal voltage and specified voltage is under 5% which is a healthy sign.

1.6. Summary of recommendations and energy saving measures:

Boilers To carry out modification and retrofit in super heater section of Boiler in order to achieve design parameter of main steam temperature of 490°C ±5°C will result in saving of 8 tons of coal per day and will reduce loading on Boiler by almost 1.8TPH, and improvement in boiler insulation will result in efficiency gain of 1% in boiler. The tentative investment for this work will be approximately INR 25,00,000/‐ and simple payback period of 58days.

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Energy and Fuel saving by installing Flash steam recovery system for Boiler Continuous Blow down (CBD) the tentative saving of fuel through this measure should be 53580Kgs of coal and tentative investment for installing this system will be of INR 4,50,000/‐ and simple payback period of 557days.

About 1‐2% improvement in boiler efficiency is possible providing improved insulation and re‐insulation of damaged areas around, APH, Economiser, manhole doors, and at various other ducting points need to be redone and by providing internal lining of fire proof cement on furnace doors cost of this work is already taken in account in first point. The tentative saving from this step will be saving of 500Ton per annum of coal consumption on account of improved boiler efficiency even if 1% gain in boiler efficiency is achieved. Resulting into monetary saving of INR27,50,000/‐.

Loss due to moisture in fuel is 0.86 % which can be brought down to a value of 0.20% by employing method for fuel moisture removal through piping a portion of flue gases at stack temperature on to the hooded conveyor of coal feed suing nozzles. Tentative investment for the duct and pipe work should be INR 3,00,000/‐ and overall boiler efficiency gain of 0.66% will result in annual saving of INR. 19,15,465/‐. Hence a simple payback period of 2 months.

Water Pumping System By replacing cooling water circulating pumps with the energy efficient pumps which will have less specific energy consumption with respect to volume of water pumped and will give recurring energy saving of 190,895units per annum if motor is also replaced by energy efficient class of Motors and 113,880 units if only pump is replaced and existing motors are utilised. Payback period for proposed replacement of pumps in case‐1 is 87days and in case ‐2 is 146days. Quotation in this regard is attached as annexure for your reference. We also recommend installation of Flow and Energy meters for all major power consuming pumps and observe flow and power pattern on regular basis (Shift and Daily basis). So that pumps having deviation in specific power consumption can be identified by plant operation team.

Cooling Tower For energy savings and better air flow consider replacement of Aluminum alloy cooling tower fan blades, with energy efficient FRP hollow fan blade. Estimated saving on account of each set of blades replaced will of 52560Kwh in case ‐1 when both Fan and motor are replaced and 26280 Kwh in case ‐2 when only fan blades are replaced with utilizing same motor. The investment for each set of blades is of INR 85,000/‐ and simple payback period on account of saving through reduced recurring energy consumption, for each set of fan blades replaced is 4months in case ‐1 when FRP Hollow Fan blades are installed with new high efficiency motor and 8 months in case‐2 if only new set of FRP Hollow Fan blades are installed with existing motor. Quotation in this regard is attached as annexure for your reference. Cooling tower fills needs to be checked for fill chocking and poor water distribution. Equal and uniform water flow to each cell to be ensured for proper distribution of water as this will improve effectiveness of Cooling Tower. Improved CT performance will allow to stop one CT fan during cold weather conditions. Monitor approach, effectiveness and cooling capacity for continuous optimisation efforts, as per seasonal variations as well as load side variations. A good chemical treatment with proper monitoring of the system will overcome all the water related problems in the system and the corrosion in the system is suspected due to improper functioning of corrosion inhibitor treatment. As PH in circulating water is around 8.5, Zn as corrosion inhibitor will

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not work perfectly at higher PH. As Zinc will precipitate at higher PH & not inhibit the surfaces perfectly, so consider organic treatment which will be a good option for corrosion control. Corrosion rack must be installed on monthly basis to check corrosion rate (mpy) in the system this system can be installed by cooling water treatment programme vendor at FoC.

Electrical system and Motors The earthing pits provided for transformer are also not adequately spaced. This causes the earthing currents to either keep circulating in the system or is injected into the ground at various stages thus increasing heat losses. Due to this a major amount of energy which is produced is not recorded in the meters and a low efficiency is recorded. The proper earthing also enhances the protection relays to function as per the design parameters and will improve system safety and reliability.

The installed capacitors need to be tested and relocated and some new capacitors need to added in the system so that the plant transmission and distribution losses are reduced. The expected annual savings from this measure should be approximately INR 36,44,160/‐. The tentative investment required for purchase of capacitors of 750Kvar is INR 3,59,950/‐ and simple payback period of 1.2 months.

12 motors are recommended to be changed with proper rating of energy efficient motors as suggested in following table:

Table: Techno economic analysis for replacement suggested motors

The capital investment required for replacing the above mentioned motors is INR 6,77,700/‐

The cumulative tentative annual saving in energy is 681959 KWH

The cumulative monetary saving should be INR 34, 09,797/‐

The cumulative simple payback period is 3 months

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Summary of overall saving The fol lowing Table presents the summary of various energy conservation measures suggested after conducting the Energy Audit of M/s Magnum Ventures Power Plant Shaibabad (UP)

SNO. ENERGY SAVING PROPOSAL ANNUAL SAVINGS

INVESTMENT REQUIRED

SIMPLE PAY BACK PERIOD

Rs. Rs. Months

1 R&M in super heater section of boiler

1,56,58,500 25,00,000 2

2 improving insulation for boiler and steam piping and by providing internal lining of fire proof cement on furnace doors

27,50,000 Nil

as cost of insulation is considered in above

immediate

3 Flash steam recovery system for Boiler CBD.

294,690 4,50,000 18.5

4 Energy Saving by Flue gas heat impingement on feed stock conveyor 19,15,465 3,00,000 2

5

Replacing cooling water circulating pumps with EE Pumps Case‐1 when motor+ pump both replaced Case‐2 only pump replaced

9,54,475

227,560 3

5,69,400 227,560 5

6

Replace CT Fan blade by EE FRP hollow fan Blades Case‐1 blade and motor both replaced Case‐2 only fan blade replaced

15,76,800 5,10,000 4

7,88,400 5,10,000 8

7 Adequately spacing earthing pits of transformer

8 Relocating and installing capacitors 36,44,160 3,60,000 1.2

9 Replacing 12 motors with high efficiency proper size of motors 34,09,797 6,77,700 3

Total 2,90,30,412 50,25,260 2.1

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2.1. Audit Objective and purpose of Energy Audit

The main objective of this exercise is to carry out specific energy consumption analysis and make recommendations for reduction in auxiliary power, optimize specific fuel consumption and to achieve a reduction in recurring expenditure on energy to improve business viability by plugging the waste energy and through improvement in the operational and maintenance practices of the facility.

2.2. Scope of Work

The aim and scope of audit is to quantify the fuel and energy consumption of the facility. It further aims

to identify the loss avenues in the systems and establish total and specific steam generation, boiler

efficiency monitoring, load balancing, run‐ability optimization and achieving best possible fuel to steam

ratio. The audit will thus cover parameter detection of:

1. Feed water inlet flow.

2. Blow Down flow estimation (If possible).

3. Inlet air temperature.

4. Temperature of exhaust to stack.

5. Feed water quality.

6. Cycle of concentration

7. Variance in phase loading of motors ACB’s and Transformer

8. Operation of motors

9. Losses due to poor capacitor behaviour or installation faults.

10. Load curves.

The completion of audit will achieve identification of all types of boiler losses and possible ECOs (Energy

Conservation Opportunities). It will highlight the efficiency improvement possibilities in motors,

capacitors and voltage variations.

The Audit has been done specifically for the steam generating unit, HVAC and Electricity Load Distribution.

This inspection report reflects the conditions of the equipment at the time of the inspection only. Please

note that equipment conditions change with time and use and the conditions noted in this report may

change in appearance and severity as time progresses or with mishandling. Hidden or concealed defects

cannot be included in this report. An earnest effort was made on our behalf to discover all fallacies;

however in the event of an oversight no liability is acceptable. No warranty is either expressed or

implied. This report is not an insurance policy, nor a warranty service.

2.3. Methodology and approach followed

ANSH ENERGY SOLUTIONS PVT. LTD, conducted the investment grade energy audit study for the 6.6MW Cogeneration Captive Thermal Power Plant of M/S Magnum Ventures Ltd., Shaibabad, Uttar Pradesh, during June, 2010. As a part of the study, the energy audit team visited the

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premises for undertaking performance assessment of various energy consuming equipments installed in the building using sophisticated energy audit instruments. The following methodology was adopted for successful conduct of the study:

• Monitoring of energy related parameters of various equipments using sophisticated and portable energy audit instruments.

• Online measurement of operating data with various instruments.

• Collection of details regarding electricity consumption in the past, maximum demand and power factor.

• Discussion with concerned officials to take note of energy conservation activities already undertaken, if any.

• Critical analysis of data collected during field visit.

o Identification of opportunities having possible energy conservation potential and quantification of energy losses.

o Identification of suitable measures for reducing energy consumption.

o Preparation of financial analysis for recommended measures.

2.4. Time Schedule for Conducting the energy audit

Field study – 4th June 2010 to 11th June 2010

Report Preparation – 12th June to 30th June

2.5. Details of the Instruments used

Following major instruments were used during the field study and data collection 1. Power and Harmonics Analyser 2. Ultrasonic Flow Analyser 3. Contact type and non‐contact type infrared temperature sensors 4. Anemometer 5. Lux meter 6. Oxygen Probe and Flue gas analyser 7. Distance meter 8. Contact type digital tachometer

2.6. Description of the Plant

Magnum Ventures Ltd. is a Paper Plant and Energy audit of its 6.6MW captive thermal power plant was carried out in the month of June 2010.

The Magnum Ventures Power Plant is having following major Plant and Apparatus:

Boiler: Thermax make, Bi‐drum, natural circulation, under bed, balanced draft, atmospheric fluidisation bed combustion, bottom supported, and membrane wall construction type of a boiler.

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This boiler is normally operated @ 35‐37Tph

Turbine: Plant is having two sets of turbo generator both of Trevani make 1st Turbine is of 4.4 Mw extraction cum condensing type and 2nd Turbine is of 2.2Mw condensing Type.

Cooling Tower: Plant is having 2 Nos of Paharpur make 1200 m3/hr flow rate, induced draft cross flow type of cooling towers.

Coal handling system: Magnum Ventures Power Plant receives coal through road and coal is stored in yard. The process flow diagram is represented as under:

Yard Coal Breaking Screen Conveyer Screen Coal Crusher Top Screw Main Elevator Screw Shoot Reject elevator

Bunker Coal Feeder

2.7. Energy Consumption Profile and Energy Management System

Table: Monthly Fuel Consumption, Steam & Power Production and Supply position

Month FEB March April May Total Coal Consumption in Ton 6368 6200 6238 4969

Cost of Coal (in Rs.) 2,54,62,199 2,61,71,530 2,57,54,803 2,41,85,169

Total Steam Generation (in Ton) 25,103 25,283 24,994 26,169

Steam supply to Plant (in Ton) 13,236 13,353 13,067 13,141

Total Power Generated (KWh) 37,59,000 38,54,500 38,28,000 40,45,000

Power Supply to Plant (Kwh) 33,39,000 34,04,000 33,18,000 34,87,000

Fuel Cost per unit of Power (Rs/Kwh) 6.77 6.79 6.73 5.98

Cost of steam (in Rs/ton) 1014.31 1035.14 1030.44 924.19

Aux Power Consumption Kwh 420,000 450,500 510,000 558,000

Aux Power Consumption Ratio % 8.95 8.56 7.51 7.25

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Figure: Feed water consumption, Steam Generation and Process Steam supply

Figure: Power Production, Power Supply to Plant and Auxiliary Power Consumption

0

5000

10000

15000

20000

25000

30000

Feb/10 Mar/10 Apr/10 May/10

Steam Genration

Steam Supply to Plant

Feed Water Consumption

0

5,00,000

10,00,000

15,00,000

20,00,000

25,00,000

30,00,000

35,00,000

40,00,000

45,00,000

Feb/10 Mar/10 Apr/10 May/10

Prower Genrated

Power Supplied to Plant

Aux Power

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Figure: Auxiliary Power ratio and cost of Steam & Power

Figure: Share of different equipments in Auxiliary Power Consumption

2.8. Equipment and Major Areas for Energy Audit

Major areas of energy audit in Magnum Ventures Power Plant were Boiler and its auxiliaries, water pumping system, cooling towers, motors and electrical distribution system. The objective of this audit was to carry out specific energy consumption analysis and make recommendations for reduction in auxiliary power.

0

1

2

3

4

5

6

7

8

9

10

Feb/10 Mar/10 Apr/10 May/10

Auxilary Power Ratio %

Cost of Steam Rs./kg

Cost of Power Rs./Unit

59%25%

11%

5%

Auxiliary Power ComponentsPumps Boiler Auxiliary CT Fan Others

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2.9. Energy Management Action Plan

2.10. References The Steam and Condensate Loop Book – Best practice guide to energy saving solutions Power Plant Engineering – P.K. Nag BEE Manual on Energy Efficiency testing (Book 4) Perry’s Handbook of Chemical Engineers (2003) Spirax Sarco website www.emerson.com www.lenntech.com/boiler‐feedwater.htm MCT31 Harmonic Calculation software and Energy Box energy savings calculation software Online turbine performance analysis by Engineering toolbox

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33.. BBOOIILLEERR

BOILER

3.1 BACKGROUND

The boiler of Magnum Ventures Power Plant is used to produce steam at the high pressure and temperature required for the steam turbine that drives the electrical generator and extracted steam from extraction cum condensing turbine is supplied to process plant used in paper manufacturing process. The boiler has furnace, steam drum, mud drum, super heater coils, and economiser and air pre‐heaters.

The air and flue gas path equipment include forced draft fan(FD), PA Fan, induced draft fan (ID), air preheaters (APH), boiler furnace, fan, fly ash collectors (electrostatic precipitators) and the flue gas stack. Brief schematic diagram of a typical system is given below.

The brief specifications of this boiler are as follows:

Particulars Unit Details at Normal Continuous

rating, NCR Make Thermax Type Water tube Bi‐drum Capacity Tph 31 Main steam pressure Kg/cm2 65kg/cm2 Main steam temperature °C 490 ± 5°C Boiler efficiency % 83 ± 2 Super heater outlet flow Tph 31 Coal calorific value‐GCV Kcal/kg 5680 (70%Coal and 30% Pet coke) Coal consumption Tph NA Total combustion air Tph LTSH outlet temperature °C 340 Water‐economiser inlet temperature °C 125 Water‐economiser outlet temperature °C 185 Oxygen content at economiser outlet % 3.5

3.2 Operational efficiency of the boiler

The boiler efficiency trial was conducted to estimate the operational efficiency under as run conditions. The efficiency evaluations, by and large, follows the loss components mentioned in the reference standards for boiler testing at site using indirect methods mentioned in BS 845:1987 as amended on date.

The method of performance assessment chosen is the indirect method of heat loss and boiler efficiency as per BIS standard 8753. The test method employed is based on abbreviated efficiency by loss method (or indirect method) tests, which neglects the minor losses and heat credits. The major losses covered are:

• Heat loss due to dry flue gas losses.

• Heat loss due to moisture in fuel

• Heat loss due to moisture in air.

• Heat loss due to hydrogen in fuel

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• Heat loss due to un‐burnt carbon in fly ash and bottom ash.

• Heat loss due to radiation to be assumed depending on emissivity of surface

• Unaccounted losses as declared by the boiler supplier

Following formula are used for estimation and calculation of Losses by indirect method:

a. Calculation for Dry Flue gases:

b. Heat loss due to dry flue gas

This is the greatest boiler loss and can be calculated with the following formula:

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c. Loss due to un‐burnt carbon in ash, Luca Loss due to un‐burnt carbon in ash, Luca=

d. Loss due to moisture in fuel, Lmf Loss due to moisture in fuel, Lmf = M*[(0.45*(FGT‐ABT)) + 584] GCV of Fuel

Where: M = is kg of moisture in 1 kg of fuel Cp = Specific heat of superheated steam in kCal/kg°C FGT = Flue gas temperature in °C ABT = Ambient temperature in °C 584 = Latent heat corresponding to partial pressure of water vapour

e. Loss due to hydrogen in fuel, Lhf Loss due to hydrogen in fuel, Lhf = 9*H2 * [(0.45 * (FGT‐ABT)) + 584] * 100 GCV Where H2 is kg of H2 in 1Kg of Fuel

f. Loss due to moisture in air, Lma

Loss due to moisture in air, Lma = AAS*humidity*0.45*(FGT‐ABT)*100/GCV Where AAS = Actual mass of air supplied Humidity = Humidity of air in kg/kg of dry air

g. Radiation and un‐accounted losses these losses considered as given in PG test/Design documents. Alternatively, the radiation losses can be estimated by measuring the surface temperatures and surface areas of the boiler section. Normally surface loss and other unaccounted losses are assumed based on type and size of the boiler as given below.

For industrial fire tube / packaged boiler = 1.5 to 2.5%

Luca= CV of carbon in Kcal/kg * [(C%FA*FAsh) + (C% BA* BAsh)] GCV of Fuel Kcal/Kg

Where C% BA ‐ % of Carbon in Bottom Ash C%FA ‐ % of Carbon in fly ash BAsh – Bottom ash quantity in Kg/Kg FAsh – Fly ash quantity in Kg/Kg

Page 10

For industrial watertube boiler = 2 to 3% For power station boiler = 0.4 to 1%

These losses can be calculated if the surface area of boiler and its surface temperature are known as given below:

LG = 0.548 X [TS/55.554] + 1.957 X (Ts‐Ta)1.25 X √Vm

Where LG = Radiation loss in watts/m

2

Vm = Wind velocity in m/s Ts = Surface temperature (°K) Ta = Ambient temperature (°K)

3.3 Blow down losses :

Dissolved salts find entry to the boiler through make‐up water which is continuously fed by the Boiler Feed Water pump ( bfw). In the boiler, there is continuous evaporation of water into steam. This leaves behind the salts in the boiler. Concentration of these salts, tend to increase in the boiler drum and starts precipitation after certain concentration level.

Water from the drum should be blown down to prevent concentration of salts beyond certain limits. Since the water in the boiler drum is at a high temperature (equivalent to it's saturation temperature at boiler drum pressure), excess blow‐down will lead to loss of energy known as 'blow‐down losses'.

Blow‐down rate reduces the boiler efficiency considerably as could be seen from the figure. Hence it is imperative that blow‐down rates are optimized, based on the hardness levels of boiler drum water which is a function of the operating pressure.

In boiler operation practice, rate of blow down increases with steam pressure as the scaling tendency increases with high temperature because the hardness limits are very stringent. While figure gives an estimate of % blow down on losses, the same may be calculated from the hardness levels of make‐up water , flow rate ,steam generation rate and the hardness level of drum water (observed).

Model given below could be used to determine the maximum limits of TDS (total dissolved solids) that could be tolerated in the boiler drum operating at various pressures. The correlation is based on American Boiler Manufacturers' Association code of practice.

However, if the limits stipulated by the Boiler Designer are less than this value, the lower of the two must be taken as the tolerance limit.

Where TDS is the permissible Total Dissolved Solids in ppm at the boiler drum and Pr is the drum pressure in psig.

The quantity of blow down to maintain the given status of boiler water in terms of TDS is determined by the material balance of solids across the boiler drum as given in the figure below.

3.4 Blow Down Rate Estimation : For estimating the boiler drum blow down rates, following nomenclatures are used.

Let F = feed water in t/hr Cm = Concentration of TDS in make‐up water in ppm Cf = Concentration of TDS in feed water in ppm. Cb = Concentration of TDS in blow‐down water m = weight fraction of make‐up water in feed water.

Page 11

Figure: Impact of Blow down Rate of fuel loss.

For establishing the blow‐down rate, a material balance on TDS is developed as shown.

TDS balance:

Wbd * Cb = F * m * Cm ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐i F = Ws + Wbd ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ii Therefore equation i may be written as Wbd * Cb = ( Ws + Wbd) * m * Cm ‐‐‐‐‐iii

Page 12

If Cf is the TDS present in the combined feed water to the boiler, above equation may be written as Wbd * Cb = ( Ws + Wbd) * Cf ‐‐‐‐‐iv

If more than the required quantity (i.e Wbd t/hr) is blown down, the excess quantity will result in lower boiler efficiency . Hence, it is imperative that boiler blow down rate is monitored continuously for achieving high boiler efficiency. An optimal blow down rate may be calculated taking into consideration the impact of high TDS on poor heat transfer vs boiler efficiency.

Table : Data Sheet for Boiler efficiency evaluation

Parameters Unit Design As run data

Duration 0900hrs to 1500hrs 07‐06‐2010

Hr

Average Unit Load Tph 35.54 % of NCR 114.65%Coal Consumption Kg 35000 Ambient parameters Dry bulb temperature °C 35 Wet bulb temperature °C 21.1 Relative humidity % 42.8 Moisture content in air Kg/kg

of air

0.014

Coal Parameters – Ultimate Analysis

Carbon (C) % 58.96 Hydrogen (H) % 7.16 Sulphur (S) % 0.56 Nitrogen % 2.02 Oxygen % 9.88 Total moisture (H2O) % 7.43 Ash % 13.99 Gross calorific value Kcal/kg 5491 Steam Parameters Main steam flow Tph 35.54 Main steam pressure Kg/cm2 65.09 Main steam temperature °C 446.41 Air/Flue gas parameters (APH inlet)

Oxygen content at inlet % 2.8 Flue gas temperature at inlet °C 205.6 Air Temperature at inlet °C 32 Air/Flue gas parameters (APH outlet)

Flue gas temperature at outlet °C 153.27 Oxygen content at outlet % Air temperature at outlet °C 155 Oxygen content at ID fan inlet % 3.7 Carbon content in fly ash % 4 Carbon content in bottom ash % 8 Bottom ash quantity (dry basis) Kg/kg of Coal 0.3 Fly ash quantity (dry basis) Kg/Kg of Coal 0.7

Page 13

The Boiler efficiency calculations are given in following table: Table: Boiler efficiency calculation for trial run period on 07th June 2010 by direct method

S.No. Feed water supplied (ton)

Steam Produced (ton)

Fuel Fired (kg)

Moisture content in Fuel (%)

Time Duratio

n (Hours)

Dry fuel weight available

Fuel Calorific value

(kcal/kg)

Available energy (gcal)

Energy attained in steam at 65kg/cm2

Overall Efficienc

y

1 217 212 35000 5.8 4 38220.0 5491 209866.02 166976.50 79.56%

Table: Steam & Power Production, Plant fuel rate and Boiler efficiency calculations

Date Feed water consumption

(ton)

Steam Production

(ton)

Coal Consumption

Power Generated (units)

Overall plant

fuel rate kg/kWh

Boiler Efficiency

4.4MW 2.2MW Total

06‐06‐2010 914 890 139 91000 44000 135000 1.03 79.25% 07‐06‐2010 872 847 136 93000 37000 130000 1.05 77.08% 08‐06‐2010 916 893 141 99000 38000 137000 1.03 78.39% 09‐06‐2010 822 796 125 89000 34000 123000 1.02 78.82% 10‐06‐2010 927 900 142 101000 39000 140000 1.01 78.44%

Table: Efficiency evaluation of Boiler by indirect method during trial run period on 07th June 2010

Parameters UnitDesign Value

Actual Value

% Deviation

Load Ton Fuel GCV Kcal/Kg 5491 loss due to dry flue gases, Ldfg % 5.52 Loss due to Hydrogen in Fuel % 7.49 Loss due to moisture in air % 0.15 Loss due to unburnt carbon in ash, Luca

% 0.67

Loss due to moisture in fuel, Lmf % 0.86 Radiation Loss % 2.2 Unaccounted loss and manufacturers margin

% Na

Heat loss due to blowdown % 1.4 Loss due to furnace door draft % 0.8 Total Loss 19.09% Boiler Efficiency (1‐Total Loss) % 83 ± 2% 80.91% 0.09%

The heat loss profile covering losses through unburnt in ash, sensible heat loss in flue gases, moisture in combustion air, loss due to presence of hydrogen and moisture in coal, radiation and unaccounted loss, are represented in above table. Above trial data is average value during 30 min. interval. It may be observed that as against 83% design efficiency, there is a margin of about 2‐3% improvement by various measures, which are largely O&E related and R&M related. About 1‐2% improvement is possible by various O&E related aspects such as providing improved insulation at furnace, APH, Economiser, manhole doors and by providing internal lining of fire proof cement on furnace doors. For further improvement in efficiency, R&M activities are required specially in the

Page 14

area of super heater so that design parameters of super heated steam can be achieved, in this regard detail techno economic and cost benefit analysis is being carried out in chapter on turbines.

3.5 Boiler Water Treatment

Water quality influences the performance of boiler internals. As energy auditors we observed the present water treatment parameters pertaining to:

Type and rated capacity Operating capacity of the internal and external treatment methods Water quality parameters Control of blow down (CBD & IBD) Condensate polishing Table: DM water, feedwater, CBDand Steam parameters as on 04th June 2010

Particulars Unit MB Feed water CBD Steam Ph 6.5 9.0 9.5 8.5 P Alk ppm Nil 1.0 6.0 1.0 T Alk ppm 3.0 5.0 12 4.0 Total Hardness ppm Nil nil Nil nil Chlorides ppm 4.0 4.2 6.3 4.0 TDS ppm 0.0 2.6 23.3 1.6

: DM water, feedwater, CBDand Steam parameters as on 01st June 2010

Particulars Unit MB Feed water CBD Steam Ph 6.5 9.0 9.5 8.5 P Alk ppm nil 1.0 5.0 1.0 T Alk ppm 4.0 5.0 10 4.0 Total Hardness ppm nil nil nil nil SiO2 ppm ‐ 0.02 1.3 0.02 Chlorides ppm 4.2 4.2 6.3 3.5 TDS ppm 0.0 2.6 23.3 1.6

Observations Overall boiler water, CBD & Steam water quality & chemistry is observed within the

prescribed limit of OEM, however it was observed that parameters like O2, residual hydrazine, metal contents like copper and iron and conductivity are not being monitored on regular basis.

CBD flow rate is observed in the range of 600‐900Liters/hr at temperature of 170 °C leaving scope for heat recovery through flash steam. The amount of flash steam which can be released by the CBD water blow down flow rate of 600Kg/hr at 1 bar g would be 199.3 kg/h of flash steam.

This flash steam recovery will reduce load on DM plant by 200Kg/hr as pure water can be recovered by installing Boiler continuous blow down (CBD) heat recovery system.

3.6 Boiler blow down heat recovery applications

Continuous blow down of boiler water is necessary to control the level of TDS (Total Dissolved Solids) within the boiler. Continuous blow down lends itself to the recovery of the heat content of the blow down water and can enable considerable savings to be made.

Page 15

Boiler blow down contains massive quantities of heat, which can easily be recovered as flash steam. After it passes through the blow down valve, if the lower pressure water flows to a flash vessel. At this point, the flash steam is free from contamination and is separated from the condensate, and can be used to heat the boiler feed tank/condensate tank or can be supplied back to Deaerator tank (see Figure for a typical application of flash steam recovery system).

The residual condensate draining from the flash vessel can be passed through a plate heat exchanger in order to reclaim as much heat as possible before it is dumped to waste. Up to 80% of the total heat contained in boiler Continuous Blow Down can be reclaimed in this way.

Figure: Typical heat recovery system from boiler blow down

Consider the CBD water and process plant condensate is being discharged to a flash vessel pressurized at 1 bar g and at temperature of 170°C. If the return line were connected to a vessel at a pressure of 1 bar g, then it could be seen from steam tables that the maximum heat in the condensate at the trap discharge would be 505 kJ/kg and the enthalpy of evaporation at 1 bar g would be 2201 kJ/kg. The proportion of the condensate flashing off at 1 bar g can then be calculated as follows: Heat in condensate at 4 bar g = 640 Kj/kg

At 1 bar g saturated condensate can only hold = 505 Kj/Kg Surplus heat in saturated condensate at 1 bar g = 135 Kj/kg

Heat in steam at 1 bar g = 2201 Kj/kg

Proportion of flash steam = 135 Kj/kg/ 2201 Kj/Kg Proportion of flash steam from the condensate = 0.061 (6.1%)

In this case, if the equipment using steam at 4 bar g were condensing 15000 kg/h of steam, then the amount of flash steam released by the condensate at 1 bar g would be 0.061 x 15000 kg/h = 919.5 kg/h of flash steam. Therefore, the amount of flash steam produced can depend on the type of steam trap used, the steam pressure before the trap, and the condensate pressure after the trap. Similarly for CBD water flash recovery

Page 16

The proportion of the condensate flashing off at 1 bar g can then be calculated as follows: Heat in condensate at 64 bar g = 1236 Kj/kg

At 1 bar g saturated condensate can only hold = 505 Kj/Kg Surplus heat in saturated condensate at 1 bar g = 731 Kj/kg

Heat in steam at 1 bar g = 2201 Kj/kg

Proportion of flash steam = 731 Kj/kg/ 2201 Kj/Kg Proportion of flash steam from the condensate = 0.332 (33.2%)

In this case, if the CBD water at 64 bar g were released @ 600 kg/h of saturated water, then the amount of flash steam released by the condensate at 1 bar g would be 0.332 x 600 kg/h = 199.3 kg/h of flash steam. Flash vessels are used to separate flash steam from condensate. Following Figure shows a typical flash vessel constructed in compliance with the European Pressure Equipment Directive 97/23/EC. After condensate and flash steam enter the flash vessel, the condensate falls by gravity to the base of the vessel, from where it is drained, via a float trap, usually to a vented receiver from where it can be pumped. The flash steam in the vessel is piped from the top of the vessel to any appropriate low pressure steam equipment.

Figure: A typical flash vessel

3.7 Energy Saving by Flash steam recovery

Energy and Fuel saving through Flash steam recovery can be calculated as under:

Page 17

The heat requirement for increasing the temperature of 199kg of cold make‐up water by 140°C (fresh make up water temperature as 30°C and flash steam temperature of 170°C), by using following Equation

Where:

Q = Quantity of energy (kJ) m = Mass of the substance (kg) cp = Specific heat capacity of the substance (kJ/kg °C) ΔT = Temperature rise of the substance (°C)

In our case m is 199Kg; ΔT is the difference between the cold water make‐up and the temperature of returned flash steam from CBD water; cp is the specific heat of water at 4.19 kJ/kg °C.

199 kg x 4.19 kJ/kg °C x 140°C = 116733.4 kJ/kg

Basing the calculations on an average for a plant in operation 8 400 h/year (350 days of operation), the energy required to replace the heat in the make‐up water is:

116733.4 kJ/kg x 8 400 h/year = 980 560.56 GJ/year

Or 27900Kcal/kg X 8400 h/year = 234360 Gcal/year

If the average boiler efficiency is 81%, the energy supplied to heat the make‐up water is:

234360 Gcal/year0.81

289333.33 GCal/year

Amount of Fuel saved considering calorific value of coal as 5400Kcal/kg = 53580Kgs

Cost of fuel saved per year considering cost of coal as Rs 5500 per ton – Rs. 294,690/‐

Cost of installing flash heat recovery system for continuous blow down shall be Rs 4.5 lacs

Simple payback period is 1.53 years or (557 days/ 80 week)

3.8 Energy Saving by Flue gas heat impingement on feed stock conveyor

Observed loss due to moisture in fuel is 0.86 % which can be brought down to a value of 0.20%.

The easiest method for fuel moisture removal is piping a portion of flue gases at stack temperature on to the hooded conveyor of coal feed suing nozzles.

A picture for example of fuel heating and moisture removal is attached below.

The saving of 0.66% amounts to ‐ 0.66% x Rs. 24185169 (May Consumption) = Rs. 1,59,622

Thus the annual savings are 1,59,622 x 12 = Rs. 19,15,465/‐

Tentative investment for the duct and pipe work = Rs. 3,00,000/‐

Hence a simple payback period = (300000/1915465) x 12 = 1.87 Say 2 months

Page 18

3.9 Energy Saving by re‐insulation of damaged areas

The damaged insulation at Economizer and APH ducts and at various other ducting points need to be redone. The reduction in radiation loss will be from 2.2% to standard 1%

Thus the savings will be = 1.2% i.e. 1.2% x Rs. 24185169 (May Consumption) = Rs. 290222 monthly or Rs. 34,82,664/‐ annually.

The cost for insulation work is Approx. 10 lacs and the simple payback comes to 10/34.82 = 3.44 or say 4 months.

The final savings are as below:

a) Savings due to Blowdown flash heat recovery = 0.4% b) Savings due to Moisture in fuel = 0.66% c) Savings due to radiation reduction = 1.2% d) Savings due to Furnace door drafts = 0.6%

Hence the boiler efficiency will be improved in total by 2.86%

Page 19

44.. WWAATTEERR PPUUMMPPIINNGG Water Pumping

4.1 Background

Water pumping is vital energy consuming area in the power plant. Major pumps in Magnum Ventures Power Plant are:

Condensate Extraction pumps Boiler feed water pumps RO/DM water plant pumps Make‐up/transfer pump Cooling water circulation pumps Raw water pumps

4.2 Energy consumption pattern for pumps:

The daily energy consumption by pumping system is as follows:

Sno. Equipment Instantaneous KW Daily Consumption KWh

Submersible pump 1 24.31 583 Submersible pump 2 15.3 367 Submersible pump 3 18.8 451 HP 2‐1 RO 15.34 276 HP 1‐1 RO 15.8 284 HP 1‐2 RO 10.96 197 HP 2‐2 RO 10.3 185 Boiler Feed Pump 1 160 3840 Boiler Feed Pump 2 148 3552 2.2 MW CT Pump 1 41.8 1003 CT Pump 2 42.6 1022 CT Pump 3 0 CEP 1 10.1 242 CEP 2 0 4.4 MW CT Pump 1 50.3 1207 CT Pump 2 46.6 1118 CT Pump 3 0 0 CEP 1 11 264

Total Kwh/Day 10754 Total energy consumption of pumping system = 10754 Kwh per day Total auxiliary power consumption per day = 16200Kwh

Page 20

Almost two third of the auxiliary power is consumed by water pumping system. Table: Design, operating parameters and efficiency of pumps

Description of Pump

Pump Specification Measured Paremeters Power

input by Motor in KW

Motor Efficiency

Pump efficiency

Make Q(flow)

in m3/hr

Head in

Meter

Motor KW RPM Flow

Discharge Pressure in kg/cm2

BFP-1 KSB 40 850 137 2980 42 80 160 88.3% 64.5%

BFP-2 KSB 40 850 137 2980 40 85 148 90.5% 68.9%

Transfer Pump Grundfos 45 50.7 11 2900 24.5 5.5 6.5 90.0% 62.5%

CEP-1 (4.4 MW) KSB 12.1 89 12.1 2900 12.8 8.8 9 85.9% 52.1%

CEP-1 (2.2 MW) Sulzer 13.5 90 9.7 2920 13.6 8.8 8.1 84.9% 55.8%

IST RO HP Pump-1 Grundfos 21 207 15 2920 20 14 15.8 87.2% 65.1%

IST RO HP Pump-3 Grundfos 21 207 16 2920 19 14 15.34 87.2% 63.9%

2nd RO HP Pump-2 Grundfos 17 135.6 11 2920 17 13 10.96 84.2% 65.0%

2nd RO HP Pump-3 Grundfos 17 135.6 11 2920 17 13 10.3 86.5% 67.3%

CT Pump-1 (4.4) NA NA NA NA 1440 400 2.2 50.3 85.8% 55.3%

CT Pump-2 (4.4) NA NA NA NA 1440 390 2.2 46.6 83.9% 58.6%

CT Pump-1 (2.2) NA NA NA NA 1440 380 2.2 41.8 73.3% 74.0%

CT Pump-2 (2.2) NA NA NA NA 1440 390 2.2 42.6 69.4% 78.7%

Raw Water Pump-1 32 2 3.6 82.0% 61.7%

Observation From the pump performance analysis based on the actual operating parameters we have observed efficiency of 4.4MW turbine condenser cooling water pumps on lower side. There is no energy and flow meters installed for major pumps

In case of pumping system pump efficiency as per industry standards is considered as Normal ‐ 60 – 75% Best ‐ 78 ‐‐ 80% (upto 89% efficiency in case of horizontal split casing pumps) Worst ‐ 30 – 60% (Reference: CII‐LM Thapar Centre for Competitiveness for SMEs)

Recommendation

We suggest replacing cooling water circulating pumps with the energy efficient pumps which will have less specific energy consumption and will give recurring energy saving of 190,895units if motor is also replaced by energy efficient class of Motors and 113,880 units if only pump is replaced and existing motors are utilised. Payback period for proposed replacement of pumps in case‐1 is 87days and in case ‐2 is 146days. We also recommend installation of Flow and Energy meters for all major pumps and observe flow and power pattern on regular basis (Shift and Daily basis). So that pumps having major power consumption can be identified.

Page 21

Table: Saving potential and cost analysis for replacing circulating cooling water pumps with new energy efficient pumps

Parameters Present Pumping System

Proposed Pumping System Case‐1

With New Motor Case ‐2

With existing motor Pump Specifications

No. of Pumps 2+1 and 2+1 Replace 2+2 by EE Pumps &

EE Motors Replace 2+2 Pumps only and

utilise existing motors Pump Type Hori Hori. B.P.O. Hori. B.P.O. Capacity NA 450m3/hr 450m3/hr Total Head 20mtrs 20mtrs 20mtrs Efficiency 86% 86% BKW at Shaft NA 22.57 22.57 Required Motor 45KW 30 KW 30 KW

Energy Consumption 41‐51Kw 25.2KW at 80% loading and

95% efficiency motor With present motor efficiency

projected motor load 30 to 35 KW

Energy consumption per day

1128KWh 605Kwh 816Kwh

Annual Energy Saving Nil 190895Kwh 113880Kwh Saving in recurring Energy cost per annum (@Rs5/Kwh)

Nil 9,54,475 INR 5,69,400 INR

Cost of New Pumps 227,560/‐ INR for 4 Pumps @56890.00 each pump Simple pay back 3months (87Days) 5months (146Days) Note:

Quote for new energy efficient pump is attached as annexure for your reference. Cost of motor is not considered in above scenario as it is worked out in Electrical & motor chapter.

For the pump used in above example calculating power requirement

450m3/hr = 125l/s .

.

=21.38Kw (approx)

Therefore Motor input power will be 21.38/0.95 = 22.51Kw Therefore annual running cost = 22.51Kw x 24h x 350 day x Rs 5/Kwh = INR 945,420/-

The approximate costs to an industrial purchaser are as follows:

Bare shaft pump alone INR 56,000/- Or Pump + Motor INR 1,37,000/-

Running costs for pump lifetime say 20 years = INR 1,89,08,400/- at present energy cost.

Comparing above costs with the running costs of pump during lifetime

Initial capital cost of pump + motor - 1.5% Maintenance Costs - 2.5% Running costs - 96%

The main conclusion to be drawn from these figures is that running costs far outweigh capital costs and should be considered far more important when specifying new equipment. Pumps and motors should be sized according to short‐term requirements. If they are oversized to cater for potential increase in water demand, then running cost, as well as capital cost, will be elevated. The pumps and their operation should be well matched to the water requirements of the process, and it important to maintain pump operation at high efficiencies for the economy of production.

Page 22

55.. TTUURRBBIINNEE

TURBINE

5.1 Background

Steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it to useful mechanical work. In Magnum Ventures Power Plant 2 steam turbines 1st is of 4.4MW Extraction cum condensing and 2nd is of 2.2MW condensing type. Following is the process flow diagram

h1

Figure: Process Flow Diagram for Magnum Ventures Cogeneration Power Plant

5.2 Turbine Efficiency evaluation

Turbine heat rate can be calculated as Turbine heat rate (Kcal/Kwh) = mass flow rate of Steam(in kg/hr) X (h1‐ h4)

P(Average power generated in KW) where

h1 = enthalpy of inlet steam in kCal/kg h2= enthalpy of extracted steam in kCal/kg h3= enthalpy of steam at condenser in kCal/kg h4 = enthalpy of feed water in kCal/kg

Turbine cycle efficiency can be calculated as Turbine cycle efficiency % = __860 X 100____

Turbine heat rate

Boiler

4.4 Mw Extraction cum Condensing Turbine

h2 Extraction at 4kg/cm2 and 210°C

H3

G

2.2Mw Condensing Turbine

G

Page 23

Table: Monthly average of Steam Supply, Power Generation, Heat rate and Turbine cycle efficiency Mon

th

Steam supply to Turbines

Steam Extraction

Power Generated

Coal Con

sumption

Overall plan

t fue

l rate

kg/kWh

4.5M

wTu

rbine Heat Ra

te

(Kcal/Kg

)

2.2M

w Turbine

Heat Ra

te

(Kcal/Kg

)

4.5M

w Turbine

cycle

efficiency %

2.2M

W Turbine

cycle

efficiency %

4.5M

W

2.2 MW

Total

4.5M

W

2.2 MW

Total

FEB 679 180 859 472 94179 40071 3759000 227 1.70 4780 2980 18.0% 28.9%

March 654 160 814 448 91259 38222 129481 205 1.59 4753 2772 18.1% 31.0%

April 644 154 798 436 91167 36433 127600 208 1.64 4683 2815 18.4% 30.6%

May 646 164 811 424 92323 38161 130484 160 1.24 4638 2846 18.6% 30.2%

Table: Monthly Fuel Consumption, Steam & Power Production and Supply position

Month FEB March April May Total Coal Consumption in Ton 6368 6200 6238 4969

Cost of Coal (in Rs.) 2,54,62,199 2,61,71,530 2,57,54,803 2,41,85,169

Total Steam Genration (in Ton) 25,103 25,283 24,994 26,169

Steam supply to Plant (in Ton) 13,236 13,353 13,067 13,141

Total Power Genrated (KWh) 37,59,000 38,54,500 38,28,000 40,45,000

Power Supply to Plant (Kwh) 33,39,000 34,04,000 33,18,000 34,87,000

Fuel Cost per unit of Power (Rs/Kwh) 6.77 6.79 6.73 5.98

Cost of steam (in Rs/ton) 1014.31 1035.14 1030.44 924.19

Aux Power Consumption Kwh 420,000 450,500 510,000 558,000

Aux Power Consumption Ratio % 8.95 8.56 7.51 7.25 Observations:

It was observed that steam generated in the boiler is of specification 65kg/cm2 and Temperature 445°C against the design temperature of 490°C ±5°C. An increase in inlet steam temperature, i.e., an increase in superheat at constant inlet pressure and condenser pressure gives a steady improvement in cycle efficiency and lowers the heat rate due to the increase in inlet temp and rising the inlet temperature also reduces the wetness of the steam in later section of the turbine and improves internal efficiency of the turbine. If the turbine inlet steam temperature is increased to 490°C ±5°C as per the design conditions then the heat energy input to the turbine will be increased and corresponding effect in cycle efficiency is achieved as illustrated in following table:

Page 24

Table: illustration of impact of inlet steam temperature on operating conditions and cycle efficiency

Present Case in which Steam at 65kg/cm2 and 445 °C

Projected Case If Steam Temp is 485°C and Pr. 65kg/cm2

Enthalpy of input steam at 445°C and 65kg/cm2

785.37kcal/kg Enthalpy of input steam at 485°C and

65kg/cm2 is 808.102kcal/kg

Saturation temp °C 280.86 °C 280.86°C

Enthalpy :@ saturation temperature 664.17 kcal/kg 664.17 kcal/kg

Enthalpy @ outlet conditions : 647 mmhg vacuum = 113 mmhg pressure absolute

= 620.5 kcal/kg 620.5 kcal/kg

Saturation temperature = 53.5 oC 53.5 oC

Net energy input = steam rate (kg/hr) *Δ Enthalpy kcal /hr

=35000 * (785.37 – 620.5)

35000 * (808.10 – 620.5)

=5770450 Kcal/hr 6566000 Kcal/hr

Carnot cycle efficiency = (445 – 53.5) x 100

(445+273) = 54.53%

= (485 – 53.5) x 100 (485+273) = 56.93%

Steam Turbines are a major energy consumer. Optimising process operating conditions can considerably improve turbine water rate, which in turn will significantly reduce energy requirement. Various operating parameters affect condensing and back pressure turbine steam consumption and efficiency. 5.3 Effect of Steam inlet pressure

Steam inlet pressure of the turbine also effects the turbine performance. All the turbines are designed for a specified steam inlet pressure. For obtaining the design efficiency, steam inlet pressure shall be maintained at design level. Lowering the steam inlet pressure will hampers the turbine efficiency and steam consumption in the turbine will increase. Similarly at higher steam inlet pressure energy available to run the turbine will be high, which in turn will reduce the steam consumption in the turbine. Figure ‐ a & b represents the effects of steam inlet pressure on steam consumption and turbine efficiency respectively, keeping all other factors constant for the condensing type turbine.

Fig a: Effect of steam pressure on steam consumption in condensing type turbine

Fig b: Effect of steam pressure on turbine efficiency in condensing type turbine

Page 25

Figure ‐ a & b indicates that increase in steam inlet pressure by 1 kg/cm2 in condensing type turbine reduces the steam consumption in the turbine by about 0.3 % and improves the turbine efficiency by about 0.1 % respectively. In case of back pressure type turbine increase in steam inlet pressure by 1 kg/cm2 reduces the steam consumption in the turbine by about 0.7 % and improves the turbine efficiency by about 0.16 % as shown in figure ‐ c & d. Improvement in back pressure type turbine is more than the condensing type turbine.

Fig c : Effect of steam pressure on steam consumption in back pressure type turbine

Fig d: Effect of steam pressure on turbine efficiency in back pressure type turbine

5.4 Effect of Steam inlet temperature

Enthalpy of steam is a function of temperature and pressure. At lower temperature, enthalpy will be low, work done by the turbine will be low, turbine efficiency will be low, and hence steam consumption for the required output will be higher. In other words, at higher steam inlet temperature, heat extraction by the turbine will be higher and hence for the required output, steam consumption will reduce. Figure ‐ e & f represents the effects of steam inlet temperature on steam consumption and turbine efficiency respectively, keeping all other factors constant for the condensing type turbine.

Fig e:Effect of steam temperature on steam

consumption in condensing type turbine Fig f: Effect of steam temperature on turbine

efficiency in condensing type turbine

Page 26

Figure ‐ e & f indicates that increase in steam inlet temperature by 10 deg C in condensing type turbine reduces the steam consumption in the turbine by about 1.1 % and improves the turbine efficiency by about 0.12 % respectively.

Fig g : Effect of steam temperature on steam consumption in back pressure type turbine

Fig h: Effect of steam temperature on turbine efficiency in back pressure type turbine

In case of back pressure type turbine increase in steam inlet temperature by 10 deg C reduces the steam consumption in the turbine by about 1.5 % and improves the turbine efficiency by about 0.12 % as shown in figure ‐ g &h. Improvement in back pressure type turbine is more than the condensing type turbine. 5.5 Effect of exhaust pressure/ vacuum

Higher exhaust pressure/ lower vacuum, increases the steam consumption in the turbine, keeping all other operating parameters constant. Exhaust pressure lower than the specified will reduce the steam consumption and improves the turbine efficiency. Similarly exhaust vacuum lower than the specified , will lower the turbine efficiency and reduces the steam consumption. Figure 2a & 2b represents the effects of exhaust vacuum on steam consumption and turbine efficiency respectively, keeping all other factors constant for the condensing type turbine. Figure 2a & 2b indicates that improvement in exhaust vacuum by 10 mm Hg, reduces the steam consumption in the turbine by about 1.1 %. Improvement in turbine efficiency varies significantly from 0.24 % to 0.4 %.

Fig 2a : Effect of exhaust vacuum on steam consumption in condensing type turbine

Fig 2b : Effect of exhaust vacuum on turbine efficiency in condensing type turbine

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The above figures also demonstrate that considerable in cycle efficiency with decrease of condenser pressure. Such decrease is mainly depending on the available cooling water temperature and thus on climatic condition of a place. Taking the current steam condition and projected steam condition the efficiency gain is projected in following tables: Table: impact of steam temperature on 2.2 MW turbine efficiency

Rated Power 2200 kW 2200 kW

HP Steam Pressure 66 bar abs 66 bar abs

HP Steam Temperature 445 °C 485 °C

Exhaust Steam Pressure 0.15 bar abs 0.15 bar abs

Full Load Isentropic Efficiency 76.0 % 80.1 %

Full Load Specific Steam Consumption 4.3 kg/kWh 4.1 kg/kWh

Source: Sugar Engineers Engineering Data software

5.6 Conclusion:

On the basis of above assumptions and theory if the turbine inlet steam temperature is maintained @ 485°C with keeping all other conditions & factors constant then the projected gain will be:

Table: cost benefit analysis for suggested modification to achieve desired steam temperature Present average steam demand per day 850 ton per day Improved steam temperature will reduce steam consumption by 5.5%, projected steam demand

803 ton per day

Saving in steam for same output 46.75 ton per day quantity of coal saved due to avoided steam generation 7.8 ton per day Cost of coal saved 42900 Rs per day Annual fuel saving 2847 ton Annual Saving 1,56,58,500 Tentative investment on boiler modification Rs.25,00,000 Simple Payback period 60 days

Page 28

66.. CCOONNDDEENNSSEERR CCOOOOLLIINNGG 6.1 Background

In power plant, the cooling tower, water pumping and condenser are involved in condensing the exhaust steam from a steam turbine and transferring the waste heat to the atmosphere. 6.2 Cooling Tower

In the following table specifications of cooling tower are given Table: Cooling tower specifications

Particulars Cooling Tower‐1 Cooling Tower‐2

Design Operating Design OperatingMake & Model Paharpur 452‐293 Paharpur 452‐293 Type Induced Draft Cross Flow Induced Draft Cross Flow No of Cells 3 3 3 3 Rated flow 1200 800 1200 750 Fill Details Treated wood splash bars Treated wood splash bars No of CT fans 3 3 3 3 CT fan KW 30 15.78/14.35/14.7 30 14.15/11.3/12.1 No. Of blades per fan 9 9 9 9 Dia of Blade assembly 144” 144” 144” 144” Blade material Cast Al alloy Cast Al alloy Cast Al alloy Cast Al alloy Hot water inlet temp °C 40 45 40 46.8 Cold water outlet temp °C 32 36.9 32 35 Wet bulb temp. °C 28 26.2 28 25.7

Cooling Tower Performance

Figure: Range and Approach

Page 29

The important parameters, from the point of determining the performance of cooling towers, are: Range ‐ is the difference between the cooling tower water inlet and outlet temperature. Approach ‐ is the difference between the cooling tower outlet cold water temperature and ambient wet bulb temperature. Although, both range and approach should be monitored, the 'Approach' is a better indicator of cooling tower performance. Cooling tower effectiveness (in percentage)‐ is the ratio of range, to the ideal range, i.e., difference between cooling water inlet temperature and ambient wet bulb temperature. Cooling capacity ‐ is the heat rejected in kCal/hr or TR, given as product of mass flow rate of water, specific heat and temperature difference.

Table: Cooling tower operating and efficiency calculations

Parameter Cooling Tower‐1

Cooling Tower‐2

Cooling Tower‐1

Cooling Tower‐2

Inlet Cooling Water Temperature °C 45 46.8 44.9 46.1 Outlet Cooling Water Temperature °C 36.9 35 37 34.5 Air Wet Bulb Temperature near Cell °C 26.27 25.7 26.27 25.7 Air Dry Bulb Temperature near Cell °C 38.33 38.8 38.33 38.8

Number of CT Cells on line with water flow 4 4 4 4 Total Measured Cooling Water Flow m3/hr 800 770

CT Range 8.1 11.8 7.9 11.6

CT Approach 10.63 9.3 10.73 8.8 % CT Effectiveness =

43.25% 55.92% 42.40% 56.86% Range ___X 100 (Range + Approach)

Rated % CT Effectiveness (Design Data) 66.66% 66.66% 66.66% 66.66%

Present water quality of makeup water & circulating water for cooling tower at Magnum Ventures, (Power Plant) Sahibabad are given in following table

Table: Water Chemistry of Cooling Tower make‐up and circulating water

Parameters Makeup water Circulating water PH 7.0 8.5 P‐ Alkanity Nil 14 M‐ Alkanity 12 70 Chloride 54 504 TDS 102 1217 Total Hardness 8 40

Observations: Cooling tower ‐1 is having low effectiveness compared to Cooling Tower‐2 CT ‐1 range found to be 7.9 and CT‐2 range found to be 11.6 against design of 8

Page 30

CT‐1&2 approach found to be 10.73 and 8.8 against design 4 indicates, low ambient temp and poor heat transfer.

CT‐1 &2, effectiveness found to be 42.40% and 56.86% against design 66.66%. which indicates poor heat transfer in CT

Power measurement indicate under loading on CT fan motors and power factor is in the range of 0.52 to 0.74. This is poor.

In Cooling Tower ‐1, Fly ash & other foreign particles are presented in reasonable quantity at most of the places like lowers, frills etc.

Regarding cooling water circulation pumps observations and recommendations are made in chapter on pumps.

As per the water quality concerned, makeup water quality is very good, here the scaling chances in the system are very less but corrosion is taking place aggressively specially in MS pipelines.

At some places in cooling water piping system corrosion observed due to which water leakage/seepage is existing.

As metal used in the cooling system are MS & Admiral brass so corrosion due to Chloride is not possible as it attacks only against SS metal, also the Chlorite level in circulating water is not very high for any trouble, with such metals (MS &AB) system may be run upto 2000ppm chloride level in the circulating water.

Water in contact with metal surface sets up an electrolytic cell where by metal undergoes slow but steady dissolution. The metal is constantly oxidized to the metal oxide in presence of water with its dissolved oxygen, unless controlled properly.

The corrosion in the system is due to improper functioning of corrosion inhibitor treatment. As PH in circulating water is around 8.5, Zn as corrosion inhibitor will not work perfectly at higher PH. As Zinc will precipitate at higher PH & not inhibit the surfaces perfectly. So organic treatment will be a good option for corrosion control.

Alkalinity in the makeup water is very less; treatment philosophy must be designed to take care of low alkalinity system to control corrosion.

6.4 Conclusion and recommendation:‐ For energy savings and better air flow consider replacement of Aluminium alloy cooling tower fan blades, with energy efficient FRP hollow fan blade. Refer table below for detail cost benefit analysis.

Cooling tower fills needs to be checked for fill chocking and poor water distribution. Equal and uniform water flow to each cell to be ensured for proper distribution of water. This will improve effectiveness of CT. Improved CT performance will allow to stop one CT fan during cold weather conditions.

Periodically clean plugged cooling tower nozzle Monitor approach, effectiveness and cooling capacity for continuous optimisation efforts, as per seasonal variations as well as load side variations.

A good chemical treatment with proper monitoring of the system will overcome all the water related problems in the system.

Corrosion rack must be installed on monthly basis to check corrosion rate (mpy) in the system.

Also Fly ash & other foreign particles adding microbiological load to the cooling system , a side stream filter may be installed to remove suspended particles from cooling towers along

Page 31

with proper bio‐dispersant dosing & Chlorine Di‐Oxide treatment in place of using oxidizing/non oxidizing biocide.

Table: Cost benefit analysis with proposed modification of cooling tower fans blade material

Parameters Present Fan System

Proposed Cooling Tower Fan System Case‐1

With New Motor Case ‐2

With existing motor Fan Specifications

No. of Fans 3 Replace Fan blade by EE FRP hollow fan Blades & EE Motors of proper rating

Replace Fan blade by EE FRP hollow fan Blades only and utilise existing motors

No. of Blades per fan 9 8 8 Dia of Blade assembly 144” 144” 144’ Blade Material Cast Al alloy FRP hollow fan Blades FRP hollow fan Blades CT Fan Motor KW 30Kw 15 30 Required Motor 30KW 15 KW 15 KW

Energy Consumption 18 Kw 12 KW at 80% loading and 95% efficiency motor

With present motor efficiency projected motor

load ‐ 15 KW Energy consumption per day

432KWh 288Kwh 360 Kwh

Annual Energy Saving Nil 52560 Kwh 26280 Kwh Saving in recurring Energy cost per annum (@Rs5/Kwh)

Nil 2,62,800 INR 1,31,400 INR

Cost of New blade set For each set of

blades 85,000/‐ INR for each set

Simple pay back For each set of

blades 4 months (118Days) 8 months (236Days)

The payback period through saving of recurring energy cost and consumption reduction by new FRP hollow CT fan blades, for each set of fan blades replaced is 4months when FRP Hollow Fan blades are installed with new high efficiency motor and 8 months if only new set of FRP Hollow Fan blades are installed with existing motor.

Page 32

77.. EELLEECCTTRRIICCAALL SSYYSSTTEEMM && MMOOTTOORRSS 7.1 Background

Different types of electrical motors are used in a power plant to drive the various equipments like: Pumps Fans Blowers

Coal handling equipments Crushers Others

These motors and connected equipments consume significant amount of energy, which contributes to auxiliary power consumption. The auxiliary power consumption of this plant varies from 7.25% to 9% during the different months.

Electrical system and Motors 7.2 TRANSFORMERS

The facility is having two transformer which are installed to step down the 6.6 KV voltage supply generated by 4.4 MW transformer.

The transformers at Magnum Ventures Limited are naturally oil cooled. They are provided with Manual Off‐load Load Tap Changer. The 2000 KVA transformer is plinth mounted and 6500 KVA transformer is mounted at height.

OBSERVATION

1. There is no sub metering of the transformers. 2. The cumulative transformation capacity is 8500 KVA for 4300 MW (5625 KVA) Alternator. 3. The earthing pits are not adequately spaced.

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RECOMMENDATION 1. There is no sub metering of the transformers. It is highly recommended to install a sub

meter on each of the transformer for monitoring the loading of the transformer. 2. The earthing pits provided are also not adequately spaced. This causes the earthing currents

to either keep circulating in the system or is injected into the ground at various stages thus increasing heat losses. Due to this a major amount of energy which is produced is not recorded in the meters and a low efficiency is recorded.

3. The proper earthing also enhances the protection relays to function as per the design parameters and will improve system safety and reliability.

7.3 POWER FACTOR ANALYSIS

The primary purpose of the capacitor is to reduce the maximum demand. The additional benefits can be derived by capacitor location. Maximum benefit of capacitor is derived by locating them close to the load. In this way the KVAr are confined to the smallest possible segment, decreasing the load current. This reduces the power losses of the system substantially. The overall power factor of the plant is being maintained at above 0.93 lagging, but the power factor of some of the individual feeders is below the satisfactory level as given in the following bar chart.

OBSERVATION

1. The installed power factor compensating capacitors through ensures an overall good PF, since they are concentrated in few panels therefore the lagging currents are circulated in the whole distribution and transmission system.

Transmission losses of plant are the losses occurring in main transformers, H.T. Cables, Switch Gear etc. = 3 % (Of total yearly Consumption). Distribution losses of plant are the losses occurring in main L.T. Cables, L.T. Switch Gear, L.T. Bus ‐Bar etc. = 7 % (Of total yearly Consumption)

Page 34

The following feeders were monitored using 3 phase power analyzer and the tentative savings at Rs. 3 per unit has been calculated for the purpose of payback period.

Table: Annual Monetary Losses due to plant Distribution and Transmission Losses

Annual Monetary Losses due to plant Distribution and Transmission Losses

Units generated at 0.8 PFL and availability Units

4400 KW Generator 24107520

2200 KW Generator 12334080

Total units generated in KWH 36441600

Plant distribution losses and transmission losses (3%) in KWH 728832

Losses in monetary terms at Rs. 5/ unit 3644160

RECOMMENDATION

1. The installed capacitors need to be tested and relocated so that the plant transmission and distribution losses are reduced. The expected annual savings are Rs. 36, 44,160.

Table: Capacitors installation Pay Back Period Calculations

Simple Pay Back Period Calculations

Total load of the feeders 1358.5 KW

Average PF of the individual feeders 0.75 lagging Improved PF 0.95 lagging KVAr required 749.892 KVAr

Investment needed Rs. 3,59,948.16 Simple Pay Back 1.2 months

7.4 LOADING PATTERNS OF MOTORS

The motors are designed to run at maximum eff ic iency when they are loaded more than 60%. The power factor of the motors also decreases drastical ly when the motor is under loaded. Similar ly, in the over loaded condition the eff ic iency, power factor, heating i .e. overal l performance of the motor decreases. Therefore, i t becomes one of the various cr iter ions to evaluate the motor performance. This not only helps improving the eff ic iency as well as takes helps in the r ight select ion of the motor capacity.

The loading pattern of the plant motors is given in fol lowing table.

Page 35

Table: Loading pattern of plant motors

OBSERVATION

1. The fol lowing motors are operating at less than 60% loading. ID Fan motor loading is being optimized with the help of VFD.

Table: List of motors operating at less than 60% loading

Page 36

RECOMMENDATION

1. The fol lowing motors are recommended to be changed with the lower capacity and eff ic ient motors .

Table: List of motors recommended for replacement with the lower capacity and energy eff ic ient motors.

The Pay Back period of the motors has been included in the motor eff ic iency sect ion of the report .

7.5 MOTOR EFFICIENCY

There are 48 motors in the power plant of capacity more than 3.5 HP. In all the operating parameters of 25 motors were successfully measured. There efficiency was calculated with the help of the measured and design data. The results are presented in the following table.

Motor Efficiency Calculation

Page 37

Table: Power Plant Motor efficiency

RECOMMENDTIONS

After calculating the efficiency and monitoring the motor loading, the following motor have been suggested to be replaced with optimum capacity efficient motors. The annual savings in KWH and monetary terms has been calculated to determine the pay back period of each of the motor.

Page 38

Table: Techno economic analysis for replacement suggested motors

The total investment to replace the above mentioned motors is Rs. 6, 77,700

The cumulative annual saving in energy is 681959 KWH

The cumulative monetary saving is Rs. 34, 09,797

The cumulative simple pay back period is 3 months

7.6 HARMONIC ANALYSIS

We have measured Harmonic Level in the plant and results are mentioned as under.

Table: Harmonic Measurement of Main Feeders

Page 39

OBSERVATION

1. The average total voltage harmonic distort ion is 6.45%. 2. The average total current harmonic distort ion is 9.3%.

Table: Harmonics Measurement of Motors

Sno. Description of Motor Voltage Harmonics Current Harmonics

3rd 5th 7th THD 3rd 5th 7th THD

1 FD Fan 0 22.4 7.7 8.6 21.8 72.9 27.7 52.6 2 ID Fan 0 22.5 6.1 6.5 4.8 22.5 11.4 47.7 3 Boiler FP 1 0 20.9 7.4 6.2 18.1 69 22.5 9.6 4 Boiler FP 2 0 19.7 4.6 5.3 5.2 21.1 6.5 9.7 5 Coal crusher 1 0 15.3 6.1 3.8 0.3 1.6 0.8 8.3 6 Coal crusher 2 0 14.7 6 5 0 2.2 0.5 9.9 7 Main elevator 1 0 15 1.2 5.3 0 0.9 0.3 9.5 8 Main elevator 2 0 5.3 1.2 5.6 1.1 9.5 2.1 10.8 9 Belt conveyor 0.5 14.2 4.1 20 4.1 9.7 3.1 13.2 10 Reject elevator 1 0 22 7 5.9 22 30 15.5 45 11 Reject elevator 2 12 Submersible pump 1 0 23.1 6.3 5.6 0.3 1.5 0.3 3.8 13 Submersible pump 2 0 8.3 4.8 2.6 0.5 0.7 1.2 3.7 14 Submersible pump 3 0 25.1 11.6 7.6 0.7 3.7 1.4 10.4 15 Ash handling motor 0 19.7 7.5 6.4 0.4 0.8 0.4 12.6 16 PA Fan 0 18.8 7 6.1 6.7 16.7 6.1 43 17 HP 2‐1 RO 0 16.3 6.1 4.5 0.3 1.9 0.6 8.2 18 HP 1‐1 RO 0 15.8 5.3 4.3 0.3 1.8 0.4 7.2 19 HP 1‐2 RO 0 16.8 7.2 4.3 0.4 1.6 0.6 8.5 20 HP 2‐2 RO 0 14 6.1 4.1 0.3 1 0.5 7.5 21 Top screw 1 0 5 1.4 5.7 2.2 12.4 2.2 16 29 2.2 MW CT Pump 1 0 5.4 0 1.3 0 0.4 0.3 1.2 30 2.2 MW CT Pump 2 0 5.2 0 1.5 0.3 0.5 0.4 2.6 31 2.2 MW CT Pump 3 32 2.2 MW CT Fan 1 0 5.2 3.1 1.5 0.4 0.8 0.4 3.9 33 2.2 MW CT Fan 2 0 4.7 0 1.4 0 0.8 8.4 3.6 34 2.2 MW CT Fan 3 0 4.6 3.1 1.4 0.4 0.6 0.4 3.8 35 2.2 MW CEP 1 0 4.5 0 1.4 0 0.5 0.3 2.9 38 4.4 MW CT Fan 1 0 20.1 5.7 5.3 0.8 3.5 1.3 14.8 39 4.4 MW CT Fan 2 0 18.1 5.5 4.8 1.5 3.2 0.6 13.4 40 4.4 MW CT Fan 3 0 15.6 7 4 0.8 2.9 1.5 10.8

OBSERVATION

1. The average total voltage harmonic distort ion is 5.34%. 2. The average total current harmonic distort ion is 13.59%.

Page 40

7.7 POWER SUPPLY QUALITY

The BIS standard specif ies that a motor should be capable of del iver ing i ts rated output with a voltage variat ion of 6%. The continuous voltage variation causes motors to heat up and thus tr iggering the deterioration of insulat ion system. The Power Factor, Sl ip and torque of the motor is also affected by the voltage variat ion.

Table: Power supply quality and Voltage Variation

OBSERVATION

1. The variat ion between the terminal voltage and specif ied voltage is under 5% which is a healthy sign.

REF - JCTE/09-10/29791 Dated : 26-06-2010 M/s Modinagar Paper Mills ltd. Modinagar U.P Sub : Quotation for FRP Fan Assembely for Cooling Tower. Kind Atten : Mr.Anubhav Gupta Dear Sir, We are receipt of your enquiry No –nil Dated :26-06-10 regarding requirement of FRP Fan Assembly for cooling tower . Now we are quoting our best. SI. NO. DESCRIPTION OF ITEM QTY UNIT RATE AMOUNT

01. FRP HOLLOW FAN BLADES COMPLETE WITH HUB . (Statically Balanced) 1Set 85,000/- 85,000.00 of 8blades No. Of Blades -8 MOC of Blades – FRP Hollow type TERMS & CONDITIONS : Delivery : With in 2-3 Weeks after receipt of your P.O. Payment : 40% Payment along with P.O. and balance payment on submission of P.I Prior to dispatch. Sales Tax : 2% against form "c" Valadity : 30 Days. Packing & Forwarding Charges : Nil Freight Charges : Extra At Actual. Insurrance : By Customer. Guarantee : 1 year from the date of supply. Thanking You Your"s Faithfully For JITENDRA COOLING TOWER (ENGS) Authorised Signatuory (J.D.Sharma) cell-9313784391

‐ 1 ‐

APPENDIX 1

What is Harmonics:- At the time of the designing any A.C. machine, it is assumed that voltage and current wave from at the output terminals of A. C. machines is assumed to be sinusoidal and consists of only one frequency which is called fundamental frequency or 1st harmonics and such sinusoidal wave from dose not contain harmonics of other frequency. Due to non linear system load such as thyristorised control, variable frequency drive and D. C. motor, a harmonics are generated at the output side of the A.C. machines and hence original sinusoidal wave form are disturbed and wave form becomes complex and non sinusoidal in nature generating 2nd, 3rd, 4th and so on frequencies of the fundamental frequency. The above phenomenon is shown in the below given diagram. These 2nd, 3rd, 4th frequencies are called harmonics of the fundamental frequency. In short waveform with frequencies other than fundamental frequency is called harmonics. 2nd, 4th etc frequencies are called even harmonics and 3rd, 5th, 7th, etc frequencies are called harmonics. Harmonics in transformer:- The non‐sinusoidal nature of the magnetizing current necessary to produce a sine wave of flux produces harmonics in current and voltage wave –forms of the three phase transformers. The effects of current harmonics:‐ 1. Increased heating of winding. 2. Inductive interference with communication circuits. 3. Increased iron losses. The effects of voltage harmonics:- a) Increased heating of winding. b). Capacitive interference with communication circuits. c). Production of large resonant voltages. Major Causes of Harmonics Devices that draw non‐sinusoidal currents when a sinusoidal voltage is applied create harmonics. Some of these devices are l isted below: Electronic Switching Power Converters 1. Computers, UPS, Solid‐state rectif iers. 2. Electronic process control equipments 3. Electronic Lightning Ballasts.

‐ 2 ‐

4. Reduced voltage motor controllers. Arcing Devices 1. Discharge l ighting. 2. Arc furnaces, welding equipments. Ferromagnetic devices. 1. Transformers operating near saturation level. 2. Magnetic ballasts. 3. Induction heating equipment chokes. Appliances

1. TV sets air conditioners, washing machines, and microwave ovens. 2. Fax machines, photocopiers, and printers. Higher RMS current and voltage in the system are caused by harmonic currents, which can result in any of the problems l isted below: 1. Blinking of Incandescent Lights‐ Transformer Saturation. 2. Capacitor Failure‐ Harmonic Resonance. 3. Circuit Breakers Tripping‐ Inductive Heating and Overload. 4. Electronic Equipment Shutting down‐ Voltage Distortion. 5. Flickering of Fluorescent l ights‐ Transformer Saturation. 6. Fuses Blowing for no apparent reason‐ Inductive heating and Overload. 7. Motor Failures (overheating) – Voltage Drop. 8. Conductor Fai lure‐ Inductive heating. 9. Neutral conductor and terminal fai lures – Additive Triplen currents. 10. Electromagnetic Load Failures – Inductive heating. 11. Overheating of Metal Enclosures‐ Inductive heating. 12. Power Interference on voice communication‐ harmonic noise. 13. Transformer fai lures‐ Inductive Heating.

Overcoming Harmonics Tuned Harmonics f i lters consisting of a capacitor bank and reactor in series are designed and adopted for suppressing harmonics by providing low impedance path for harmonic component. The harmonic f i l ters connected suitably near the equipment generating harmonics help to reduce THD to acceptable l imits. For overcoming and troubleshooting of some problems in the electrical power system

‐ 3 ‐

HARMONICS WAVE FORM

‐ 4 ‐

APPENDIX 2

Power factor improvement with the use of static capacitors:‐ In case of alternating current power supply system current is always lag behind the voltage. This is due to the fact that the A.C. machines works on the principle of electromagnetic induction and these A.C. machines consume reactive power for their own needs for formation of magnetic flux and this phenomenon will cause current vector to lag behind the voltage vector and this will generates the P.F. in the system. The above fact is shown in below sine wave diagram.

What is Power Factor:‐ The P. F. = CosØ is the ratio of KW = Active Power KVA Apparent Power Methods of improving power factor:-

1. With the use of static capacitors. 2. With the help of synchronous condenser. 3. With use of phase advancers.

‐ 5 ‐

Here we can discuss the use of static capacitor and there advantages for improving How Power factor improves with the use of static capacitors:‐ The static capacitor generates reactive current of opposite nature at leading power factor when connected to the supply mains parallel to inductive load and compensates reactive current of the inductive load, which is running at lagging power factor. ∴ When static capacitor is connected parallel to the inductive load, the inductive load starts receiving reactive power of opposite nature at leading power factor from the capacitors and thus this reactive power neutralizes the inductive power requirement of the load and thereby improves the P. F. of the load. The above Explanations are made simple with the below mentioned Vector Diagram.

The P. F. = CosØ is the ratio of KW = Active Power

KVA Apparent Power Vector diagram and physical diagram of inductive load with use of capacitor

‐ 6 ‐

Effect of Different Power Factor on 100 KW Industrial Motor Working Load:­ Assume 3 phase, 100 KW rating inductive motor., V = 415, P.F. = Cos ↓ = Cos 0° = 1,

∴↓ = 0°, F = 50 HZ, Efficiency = 90 % Sin ↓ = Sin 0° = 0

η Of Motor = Output Input = 1.73 x V x I x Cos ↓ = output x 100 Input η I = 100 x1000 1,73 x 415 x1 x 0.90 I (line) = 155 Amp. Active Current = I active = I(line) x Cos ↓ = 155 x 1 = 155 Amp. Reactive Current = I reactive = I(line) x Sin ↓ = 155 x 0 = 0 Amp. The KVA = KW = 100 =100 KVA

Cos ↓ 1 KW = KVA x Cos ↓ = 100x1 = 100

‐ 7 ‐

KVAr = KVA x Sin ↓ = 100x0 = 0

Vector Diagram Active Power – (KW) = 100 Reactive power‐(KVAr) = 0 Apparent or resultant power – (KVA) = 100 (B) 100 KW load working at Cos ↓ = P. F. =0.90, ∴↓ = 25° The KVA = KW = 100 = 111 KVA Cos ↓ 0.90

Line Current = I (line) at P.F of 0.90 = 155 Amp./ 0.90 = 172 Amp Active Current = I active = I(line) x Cos ↓ = 172 x 0.90 = 155 Amp

Reactive Current = I reactive = I(line) x Sin ↓ = 155 x 0.422 = 64.4 Amp. KW = KVA x Cos ↓ = 111x0.90 = 100 KVA = 111 KVAr = KVA x Sin ↓ = 111x0.422 = 47

­: Vector Diagram :­ Active power – (KW) = 100 KW

↓ = 25° Voltage vector ‐ V Current vector – A . Reactive power–(KVAr) = 47 Apparent or resultant power – (KVA) = 111

(C) 100 KW load working at Cos ↓ = P. F. = 0.80, ∴↓ = 36.8°

Line Current = I (line) at P.F of 0.90 = 155 Amp./ 0.80 = 194 Amp

Active Current = I active = I(line) x Cos ↓ = 194 x 0.80 = 155 Amp

‐ 8 ‐

Reactive Current = I reactive = I(line) x Sin ↓ = 194 x 0.599 = 116 Amp The KVA = KW = 100 = 125 KVA

Cos ↓ 0.80 KW = KVA x Cos ↓ = 125x0.80 = 100 KVA = 125 KVAr = KVA x Sin ↓ = 125x0.599 = 75 ­: Vector Diagram :­

Active power – (KW) = 100 KW ↓ = 36.8° Voltage Vector ‐ V Reactive power–(KVAr) = 75

Current vector ‐ A

Apparent resultant power – (KVA) = 125

From the above vector diagrams and below mentioned calculation it can be seen that at (A) 100 KW load and P. F. = 1 ∴KVA = 100 KVA ∴ Demand charges = 100 x Rs.200 = Rs.20000/‐ (Assuming Demand Charges = Rs. 200 /KVA) (B) 100 KW load and P. F. = 0.90 ∴KVA = 111 KVA ∴ demand charges = 111 x Rs. 200 = Rs.22200/‐

‐ 9 ‐

APPENDIX 2A

Methods of testing & checking of capacitors:‐

• With the help of AVO meter ‐ A good capacitor will show dead short between

any two terminals first & then charge up to battery voltage.

• Megger test‐ A good capacitor will show infinity resistance between any

terminals & earth.

• With the help of Ampere meter ‐ A good capacitor will draw rated current at

rated voltage.

We suggest checking the APFC capacitor current ratings, every week and replacing any

faulty capacitors as soon as possible.

Importance of good Power Factor and various benefits thereof: ‐

1. The KW capacity of the prime movers is better utilized.

2. The KVA capacity of the transformers and cables are increased.

3. The efficiency of every plant is increased.

4. The overall production cost per unit decreased.

5. Heat losses in any electrical machine = k x 1/P.F. and hence high P. F. will generate less

heat.

6. Reduction of plant electrical losses due to improvement of P. F. = 1

7. KVA reduction =

Disadvantages of poor power factor: ‐

1. Losses in any electrical equipment are proportional to i² which means proportional to

1/P.F.² thus losses at P.F. = Unity = 1 and losses at P.F. = 0.8 are 1/ [0.8] ² = 1.57 times

higher than those at unity P. F.

‐ 10 ‐

2. Rating of motors and transformers etc. are proportional to current hence to 1/P. F.

therefore large motors and transformers are required.

3. Poor P. F. causes a large voltage drop, hence extra regulation equipment is required to

keep voltage drop within prescribed limits.

Indirect benefits of improved P. F.:- (Example for understanding) 1. Losses reduction of the plant due to improvement in P. F. from P. F. 1 (0.92) to P. F. 2

(0.98)

Now we are raising the existing P. F. of 0.92 to new P. F. of 0.98.

Therefore, monthly energy loss reduction in the plant, due to improvement of PF

= 1

= 1 ..

= 1 – 0.8812

= 0.1188

= 11.88 %

When current I amperes flow through any electrical machines having resistances R ohms for t

seconds the electrical energy expended is I² x R x t joules.

∴Heat produced = I² x R x t / 4187 kilocalories.

∴Heat produced at PF 1 (0.92) = k [1/ (PF 1)2] & Heat produced at PF 2 (0.98) = k [1/(PF 2)2]

∴Reduction in heat generation due to improvement of P. F.

=

= k x [ 1.1814 – 1.0412 ]

= k x 0.1402 Calories

‐ 11 ‐

APPENDIX 3 Motor Efficiency Test (No Load Method) We have taken measurement 10 HP motor for calculation of efficiency. Motor Specifications Rated power = 7.5 kW/10 HP Voltage = 415 Volt Current = 17 Amps Speed = 935 RPM Connection = Delta No load test Data Voltage, V = 424 Volts Current, I = 5.9 Amps Frequency, F = 50 Hz Stator phase resistance at 20 °C = 2.5 Ohms No load power, Pnl = 156 Watts ( a) Let Iron Plus Friction and windage Loss , Pi + fw No load Power Pnl – 156 Watt

Stator copper Loss, Pst @ 20oC (Pst.Cu)

= 3 x (5.9/1.73) 2 x 2.5 = 87.23 Watt Now Pi + fw = Pnl – Pst.cu = 156 – 87.23 = 68.77 Watt

(b) Stator Resistance at 120 C

2.5

3.48

(c) Stator Copper Losses at Full Load Pst.cu 120 0 C

= 3 x (17/1.73) 2 x 3.48 = 1008.32 Watt

‐ 12 ‐

(d) Full Load Slip =

= 0.065

Thus, Input to Rotor =

.

.

= 8021.40 (e) Total Full Load Input Power = 8021.40 + 1008.32 + 68.77 + 37.5 ( stray Losses 5 % of rated Output) = 9135.99 Watt Say 9136 watt

(E) Motor efficiency at Full Load =

= 82.09 % say 82 % Above test clearly shows that Old and many times rewind Motors have very low efficiency as compared to new Energy efficient Motor. New Energy Efficient Motors have efficiency up to 95%. So you are advised to avoid the use of old rewound motors or motor with stated efficiency of less than 90% on test certificate in future. Above motors have total measured running load as 463.75 KW and average efficiency of 83.6%. Replacement of motors can bring the efficiency of 95% on running load thus improving efficiency by 11.4% and subsequently reducing the load by 52.86 KW. This will result in savings of 52.86 x 20 hrs per day x 30 days = 31716 KWH each month = 31716 x 4.19 = INR 1,32,890 each month

TentatSalvagThus n HenceWe remotor

­: Pow

tive investge Value ofnet investm

simple pacommends and mai

wer Stag

tment of 4f old motoment = 11

ayback = 9d use of Bntain very

ges In An

410.88 KWors = 400 x109382 – 1

924182/13aldor moty high effi

n Induct

W = 410.88x 463 KW 185200 = I

32890 = 6tors whichciency eve

tion Mo

8 x 2700 p= INR, 1,8INR 9,24,1

.95 say 7 h are NEMen at 25%

tor:­

er KW = IN85,200 182

Months.MA Premiu loading.

NR 11,09,

um efficie

‐ 13 ‐

382

ncy range

‐

e

‐ 14 ‐

Variation of Motor Efficiency /P. F / Stator Current / Torque & Speed with receipt to Load Demand Power Loss Due to Under Load Operation of Induction Motor (% of Power Loss in Motor):­ Whenever induction motors runs in under load conditions, heavy power losses are observed and hence under loading and no load running of the inductions motor are to be avoided. For our customers knowledge a following chart of power losses is attached. Power Loss Due to Under Load Operation of Induction Motor (% of Power Loss in Motor) :­

Motor Capacity in H.P.

No Load 25 % Load 50 % Load Full Load

5 50 40 25 18 7.5 45 30 20 1710 44 26 18 17 15 43 23 17 14 20 42 20 15 14 25 41.5 19 15 13 30 41 18 14 13 40 40 17 15.5 10.5 50 40 16 12.5 10 60 39 15.5 12.5 10 75 38.5 13 12 9 100 38 13 12 9

Motor Rating (HP)

Capacitor rating (kVAr) for Motor Speed3000 1500 1000 750 600 500

5 2 2 2 3 3 3 7.5 2 2 3 3 4 4 10 3 3 4 5 5 6 15 3 4 5 7 7 7 20 5 6 7 8 9 10 25 6 7 8 9 9 12 30 7 8 9 10 10 15 40 9 10 12 15 16 20

‐ 15 ‐

50 10 12 15 18 20 22 60 12 14 15 20 22 25 75 15 16 20 22 25 30 100 20 22 25 26 32 35 125 25 26 30 32 35 40 150 30 32 35 40 45 50 200 40 45 45 50 55 60 250 45 50 50 60 65 70

Table – Rating of Capacitor required for different rating and speed.

‐ 16 ‐

‐ 17 ‐

APPENDIX 4

Performance Evaluation of Motors Electrical motors accounts for a major part of the total electrical consumption. So a careful attention should be given to the performance of this utility. Measurements of the different electrical parameters of the major motors of the plant are given in Table The efficiency of the induction motor and loading condition of the motors are directly proportional to each other. Higher the loading and higher is the efficiency of the motors. The best efficiency of the motors is achieved at a load very much near to the rated load. Moreover at lower loads the power factor is on the lower side increasing the load current and thereby increasing the copper losses, resulting in lower efficiency, the rating of the motors should be decided after carefully understanding the process requirement in the absence of which the motor might come out to be oversized. Also one should run a motor, which has been rewound more than once as every time a motor is rewinded it losses 2 – 5% of its actual efficiency. Motor performance is affected considerably by the quality of input power that is the actual volts and frequency available at motor terminals, vis‐à‐vis rated values as well as voltage and frequency variations and voltage unbalance across the three phases. Mostly all the motors are old or rewound at least once. A good saving can be achieved if higher efficient ones replace them. Though it’s a scheme with higher initial investment but can be implemented phase wise. Induction motors are characterized by power factors less than unity, leading to lower overall efficiency (and higher overall operating cost) associated with a plant’s electrical system. Capacitors connected in parallel (shunted) with the motor are typically used to improve the power factor. The impacts of PF correction include reduced KVA demand (and hence reduced utility demand charges), reduced I2R losses in cables

‐ 18 ‐

(leading to improved voltage regulation), and an increase in the overall efficiency of the plant electrical system. It should be noted that PF capacitor improves power factor from the point of installation back to the generating side. It means that, if a PF capacitor is installed at the starter terminals of the motor, it won’t improve the operating PF of the motor, but the PF from starter terminals to the power generating side will improve, i.e., the benefits of PF would be only on upstream side. The size of capacitor required for a particular motor depends upon the no‐load reactive KVA (KVAR) drawn by the motor, which can be determined only from no‐load testing of the motor. Higher capacitors could result in over‐voltages and motor burnouts. Alternatively, typical power factors of standard motors can provide the basis for conservative estimates of capacitor ratings to use for different size motors.

‐ 19 ‐

APPENDIX 4A

We are suggesting some Measures to Improve Efficiency of Motors and Distribution system 1: Electrical Distribution Correction Measures available to improve power quality and reduce electrical losses are

1. Maintain voltage level close to nameplate level as far as possible, with a maximum deviation of 5% (at 5% under voltage, copper loss is increased to 10%).

2. Minimize phase imbalance within a tolerance of 1%. As deviation of one phase voltage from average phase voltage increases, it will result in increased winding temperature.

3. Maintain high power factor to reduce distribution losses. 4. Avoid excessive harmonic content in the power supply system, as increased

harmonic content in power supply system will increase motor temperature. 5. Use oversize distribution cable in the new installation to reduce copper

losses. This will also help in reducing voltage drop during starting and running and minimizing the motor losses.

2: Motor Efficiency Improvement The measures available to improve motor efficiency are:

1. If motor is running at partial load then convert motor from delta to star connection. This will improve motor efficiency.

2. Replace rewound induction motor (with reduced efficiency) with new energy efficient motor.

3. If process demands oversized motor then possibility of use of VFD may be explored to save energy. This is also applicable in case of varying load duty cycle motor application.

4. Control the motor drive temperature. This will reduce copper losses and increase motor life.

‐ 20 ‐

3: Better System Matching Measures available are:

1. Use an on/off control system using timer, PLCs, etc to provide motor power only when required.

2. Size the motor to avoid insufficient low load operation. Motor should run at 65% to 95% of its nameplate rating to get maximum efficiency.

4: Driven Load and Process Optimization Measures available to optimize the process and its operation are:

1. Change or reconfigure the process or application so that less input power is required.

2. Downsize the over sized pumps, fans, compressors or other driven loads if possible.

3. Install more efficient mechanical subsystems. Check that coupling, gearbox fan or pump must be energy efficient.

Miscellaneous Measures to Improve Motor Efficiency

Maintenance Energy savings of 10 to 15 percent of motor energy consumption can typically be realized, depending on change from existing maintenance practices. These are:

1. Proper lubrication: it will minimize wear on moving parts. Lubrication is best done on a regular schedule to ensure wear is avoided. Once it occurs, no lubricant can undo it. It is crucial that the correct lubricant is applied in the right quantities.

2. Correct shaft alignment: It ensures smooth, efficient transmission of power from the motor to the load. Incorrect alignment puts strain on bearings and shafts, shortening their lives and reducing system efficiency. Shafts should be parallel and directly in line with each other. It is necessary to use precision instruments to achieve this. Shaft alignment is an important part of installation and should be checked at regular intervals.

3. Proper alignment: Belts and pulleys must be properly aligned and tensioned when they are installed, and regularly inspected to ensure alignment and

‐ 21 ‐

tension stay within tolerances. Abnormal wear patterns on belts indicate specific problems that may require correction. Loose bests may squeal and will slip on the pulleys, generating heat. Correctly tensioned pulleys run cool. Excess tension strains bearings and shafts, shortening their lives.

4. Painting of motor: Avoid painting motor housing because paint acts as insulation, increasing operating temperatures and shortening the lives of motors. One coat of paint has little effect, but paint buildup accumulated over years may have a significant effect.

‐ 22 ‐

APPENDIX 5 Maintenance Schedule of MOTOR for Energy Conservation i). Daily: ‐

Clean the motor and starter. ii). Weekly: ‐

Clean slip rings with soft brush dipped in white spirit. iii). Monthly: ‐

Check earth connections of motor and starter. Blow through motor and starter with dry compressed air at 2 Kg/Cm2 . Check tightness of cable connections. Check motor for overheating and abnormal noise / sound, sparking and for proper bedding of brushes. Tighten belts and pulleys to eliminate excessive losses.

iv). Quarterly: ‐

Check motor terminal voltage for balanced supply. If more than +1% of average, then check from transformer onward. Carry out SPM checks viz. vibrations and sound of bearing. Record reading and compare With earlier / other motor readings. Slip Ring: ‐ Inspect the brushes and make sure that they move freely in the brush holder clips. Clean brushes, holder chip and wipe with cloth dipped and in gasoline. Replace the brush if they are worn out less than 5 mm in length from brush holder. Clean the starter and motor contacts with white spirit.

v). Six Monthly Maintenance: ‐

Check over load mechanism of starter. Check alignment of motor with driven equipment. Check no load current and compare with earlier / original. Check / change lubrication as per lubrication schedule given on next pages. Check the securing foundation nuts for tightness. Inspect the paint coating and do‐touching wherever required. Check IR(Insulation) Resistance of motor and starter with 500 V megger. It should be

more than 2 MΩ