A study of energy audit,conservation and management measures in Indian thermal power stations for enhancing power generation

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A STUDY OF ENERGY AUDIT, CONSERVATION Et MANAGEMENT MEASURES IN INDIAN THERMAL

POWER STATIONS FOR ENCHANCING POWER GENERATION

THESIS

SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

By

I. P. S. PAUL

Centre of Energy Studies

INDIAN INSTITUTE OF TECHNOLOGY, DELHI

April, 1996

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CANDIDATE'S DECLARATION

I hereby declare that the work presented in this thesis entitled "A STUDY OF ENERGY AUDIT, CONSERVATION AND MANAGEMENT MEASURES IN INDIAN THERMAL POWER STATIONS FOR ENHANCING POWER GENERATION" in fulfillment of the requirements for the award of the degree of Doctor of Philosophy, submitted to the Centre for Energy Studies, Indian Institute of Technology Delhi, is an authentic record of my own research work carried out by me at CPRI/NPTI/NTPC/IITD during the period from 1989 to 1996 under the part-time guidance of Prof. S.P. Sabberwal and Prof. S.C. Kaushik, Centre of Energy Studies, Indian Institute of Technology, Delhi. I further state that while collecting, compiling and analysing relevant data embodied in the thesis, necessary permission and cooperation from power stations/concerned authorities was obtained. I am fully responsible for data collection, measurements during technical visits and experimental works carried at site/laboratories for Energy Audit and Allied Studies. The matter embodied in this thesis has not been submitted by me or anybody else for the award of any other degree to any other university or institute.

I. P. S. PAUL

Ph.D. Registation No. 89 RES 008

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CERTIFICATE

This is to certify that the thesis entitled 'A STUDY OF ENERGY AUDIT, CONSERVATION AND MANAGEMENT MEASURES IN INDIAN THERMAL POWER STATIONS FOR ENHANCING POWER GENERATION' being submitted by Shri I.P.S. Paul to Indian Institute of Technology, Delhi for award of the Degree of Doctor of Philosophy is a record of the work undertaken and carried out by him at CPRI/NPTI/NTPC/IITD under our part-time guidance and occasional supervision. To the best of our knowledge and belief, the research material contained in this thesis in present form has not been submitted by him or anybody else in part or full to any other University or Institute for award of any other degree, as declared by the candidate.

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Prof S.P.Sabberwal Prof S.C. Kaushik

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ACKNOWLEDGEMENT

It's my pleasure and privelage to gratefully acknowledge the guidance and cooperation of my thesis supervisors, Prof.S.P Sabberwal and Prof.S.0 Kaushik of the Centre for Energy Studies, Delhi for suggesting the most relevant topic of research. My sincere thanks are for their valuable suggestion, encouragement and timely help without which it was difficult to complete the studies on part time basis.

I am also thankful to 1.I. T. Delhi and Head, Central of Energy Studies for providing.

all facilities and assistance at all stages.

I am grateful to Shri M.N.God, former Director General, PETS (Now named NPTI) and Joint Secretary, Ministry of Power, for permission to undertake Ph.D studies in July '89. Consequent to joining CPRI, in September '92 Dr. M. Ramamoorty, former Director General-CPRI consistently encouraged me to complete the work as soon as possible. Senior officers of National Power Training

Institute who helped me in various stages were Shri V.S.Lothe, Chief Superintendent, Nagpur, Shri Prithvipal Singh, Director (Finance & Admn.), Shri A.Arunachalam, Chief Superintendent Neyveli. At CPRI support of Shri M. K. G Pallai, Director General, Shri V. Jayachandran, Dr. P.R. Krishna Murthy, Shri. V.B. Ram Mohan and Shri S. Sridharan Additional Directors is gratefully acknowledged. Deep apprecation for the help and cooperation of Shri 1. Budding, Shri Mahender Singh and Smt. V. Bhardwaj is duly acknowledged.

The grateful thanks are also expressed for the kind co-operation of authorities of Power, Ministry of Power- GOI, NLC, NTPC, APSEB, MPEB, TNEB, CPRI in

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sponsoring Energy audits and permitting use of data/ information collected analysed and presented in various chapters. 1 am grateful for permitting to undertake technical study visits in their power stations and numerous suggestions to improve the quality of research.

Excellent facilities provided by CPRI, NPTI, NTPC, HT, (Delhi) at various stages of this project while my postings in New Delhi, Durgapur, Neyveli, Nagpur and Bangalore are gratefully acknowledged. I express sincere gratitude to Shri K.R.

Krishnaswamy, Dr. S. Seetharamu, Shri M. Siddhartha Bhat, Shri R. P. Mandi, Shri B.B. Gujala for the kind assistance in carrying out various measurements and laboratory experiments.

The people behind the scene are more vital and among them are my wife Mrs. Sukhinder Paul, daughter Geetika and many of my collegues in Materials Technology, High Power Laboratory and Electrical Apparatus Testing Divisions.

I am extremely indebted to them for their kind help and willing support.

Last but not the least, I want to place on record my indebtness to Prof S. C. Kaushik for his personal guidance, painstaking efforts and deep interest in thesis. His moral support and effective criticism of the thesis work is worth appreciation and I wish that every student should get such an able and devoted guide for the heart breaking thesis work.

I.P.S PAU\-)k\r\L

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SUMMARY

The thermal power stations are installed to convert available energy in coal/

lignite/petroletim products into electricity. Besides economy, efficiency and environment considerations, the energy consumptions in power generation is of prime significance. The thesis presents some energy auditing studies for savings in auxiliary power, coal, oil etc. and thereby achieving the main objectives of increased power generation, improved efficiency and economy in Indian thermal power plants.

The literature survey has revealed that about 70% of India's power requirements are being met by 329 coal fired thermal power stations having unit sizes from 30 MW to 500 MW. Consistant developments from operating the plants based on conventional approaches for effective end use of energy, installing energy efficient equipment using computer aided designs/ operation/maintenance have taken place from time to time. However, energy conservation & management measures in an integrated manner have not been studied for practical applications in actual operation and maintenance of these plants. Thus this doctorate thesis was under taken as a project for Indian thermal power stations and the results are for direct applications in the field. The author had conducted actual field studies/investigations and gathered relevant data from power stations all over India located particularly in Madhya Pradesh, Andhra Pradesh & Tamil Nadu and had carried out detailed energy audit studies in their coal fired thermal power stations. Energy auditing measurements covered study of thermal plants, process/equipment, oil, coal and combustion as well as steam/water ciruits, auxiliary power consumption in pumps, fans, mills, lighting, transformers, and over-all energy management systems. The collection and analysis of coal and ash samples by laboratory experiments, measurements at actual plant site(s), compilation of data and parametric readings alongwith their numerical appreciation by Computer Graphic Software for curve fittings on PC-AT-486 have been reported and practical/feasible recommendations

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for energy saving have been made.

The study of optimum economy and efficiency in energy consumption during (a) start up (b) normal running and (c) shut down of the typical 210 MW thermal power plants covered problems leading to delays, and excessive energy consumption. Remedial measures like standardisation approaches; near elimination of air leakages in boiler ducts, electrostatic precipitators and air preheater; optimisation of coal fineness/common auxiliaries, operational ease and monitoring have been suggested.

Energy analysis for performance evaluation has been stressed by energy accounting, testing of plant components, consistant monitoring of controllable parameters. These parameters include flue gas analysis at economiser/air preheater outlets, humidity of air, coal quantity/quality, unburnt combustibles in fly ash and flkke gases etc. Significance of accurate instruments, repeatability, proper location is stressed. A simple energy balance for the 210 MW thermal power plant boiler has been presented for identifying the energy distribution ratios.

The role of condenser-vacuum, excess air, sliding pressure operation, renovation and modernisation has also been discussed. The energy efficient technologies in variable speed (frequency) drives, fluidised bed boilers, tower top and once through boilers too have been recommended as futuristic technologies for enhanced power generation.

The main effort in the thesis first of its kind in India has been in conserving energy at the existing Indian plants by energy auditing, renovations and maintenance and suggesting practical measures/ techniques for skilled technicians and plant engineers/managers. It is vital because by using even about one tenth the generation cost, time/effort and energy, enhanced energy generation is possible by implementing the aforesaid conservation measures. These measures have found wide acceptance and appreciation from power station authorities, Central Electricity Authority and Ministry of Power, Govt. of India.

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CONTENTS

Page No.

Candidates Dec-laration Certificate

Acknowledgement Summary

Preface

Nomenclature

List of Tables and Figures

I INDIAN POWER SCENARIO - SURVEY OF STRATEGIES AND

ROLE OF ENERGY CONSERVATION IN THERMAL SECTOR 1-10 1.1 Introduction

1.2 Power Generation Resources 1.3 Problems of Power Generation 1.4 Outlook for the Future

1.5 Eighth Plan Proposals for the power sector 1.6 Thermal Power Development

1.7 Energy Conservation Programme in Eighth Plan and its Interface with Thermal Power Generation 1.8 Energy Conservation Programme in Eighth Plan 1.9 Investment in Energy Conservation

1.10 Strengthening infractrusture 1.11 Conclusions

II LITERATURE SURVEY OF SYSTEMATIC APPROCHES FOR ENERGY

CONSERVATION IN THERMAL POWER GENERATION 11^-27 2.1 Introduction

2.2 Basic principle of organising an energy management programme in TPS

2.3 Organising an energy management programme 2.4 Energy audit related to power plants

2.5 Energy Audit-An Integral step in Management Process 2.6 The energy audit: its role in TPS

2.7 Computer based energy management systems

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2.8 Survey of Energy conservation Technology 2.9 Identification of counter measures

2.10 Review on Energy Conservation in Indian Thermal Power Stations

2.11 Conclusions

III ENERGY AUDIT STUDIES IN A TYPICAL 30 MW

THERMAL POWER STATION 28-49

3.1 Introduction

3.2 Energy Audit Studies in a 30 MW Thermal Power Station 3.2.1 Thermal Power Plant Description

3.2.2 The Process and Equipment

3.3 Results of Energy Audit Studies 3.4 Energy Management System

3.5 Conclusions

IV ENERGY AUDIT STUDIES IN A TYPICAL 62.5 MW

4.1 4.2 4.3

The Thermal Power Station Description The Process and Equipment

Results of Energy Audit Studies 4.4 Energy Management System

4.5 Conclusions

V ENERGY AUDIT STUDIES IN A TYPICAL 110 MW

5.1 The Thermal Power Station Description 5.2 The Process and Equipment

4.5 Conclusions

VI ENERGY AUDIT STUDIES IN A TYPICAL 120 MW

6.1 The Thermal Power Station Description

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6.2 The Process and Equipment

6.5 Concusions

VII ENERGY AUDIT STUDIES IN A TYPICAL 210 MW THERMAL POWER STATION

7.1 The Thermal Power Station Description 7.2 The Process and Equipment

7.5 Conclusions

122-151

VIII, OPTIMUM ECONOMY AND EFFICIENCY IN ENERGY CONSUMPTION DURING START-UP, SHUT DOWN AND NORMAL RUNNING

OF 210 MW THERMAL POWER STATIONS 152-171 8.1 Introduction

8.2 Site Trials Analysis of Problem of Delays

8.3 Delay Due to Turbine Expansion and Associated Problems

8.4 Delay Due to Generator Windings Dry Out

8.5 Starting/loading and Stopping of Power Generating Unit with Minimum Number of Auxiliaries

8.6 Standardization Approaches for Minimum Number and Timely Running of Auxiliaries While Start up/Shut down of Unit

8.7 Reduction in Auxiliary Energy Consumption During Normal Load Operation of the Thermal Power Station 8.8 Conclusions

IX PERFORMANCES MONITORING AND ENERGY ANALYSIS FOR ENERGY EFFICIENCY IMPROVEMENT IN

THERMAL POWER STATIONS

9.1 Introduction

9.2 Methods of Performance Monitoring 9.3 Boiler & Turbine Tests

172-185

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9.4 Vital Controllable Parameters

9.5 Energy Analysis of Typical 210 MW Plant 9.6 Performance Improvement through Plant

Rehabilitation and Modernisation

9.7 Key Role of Parameters Influencing Efficiency 9.8 Optimal Control by Performance Monitoring 9.9 Some Practical Aspects of Monitoring

9.10 Conclusions

X ADDITIONAL ENERGY CONSERVATION BY MEASURES TECHNOLOGICAL OPTIMISATION, ENERGY EFFICIENT

EQUIPMENTS, RENOVATION AND MODERISATION AND FUTURISTIC TECHNOLOGIES

10.1 Introduction

10.2 Components Constituting Energy in TPS 10.3 Conservation of Coal/Lignite

10.4 Conservation of Steam

10.5 Sliding Pressure Operation 10.6 Conservation of Furnace Oil 10.7 Role of Excess Air

10.8 Savings Through Auxiliary (Works) Power

10.9 Enhancing Energy Conservation and Efficiency by Renovation & Modernisation in Thermal Power Plants 10.9.1 Investigations & Analysis for poor performance of

Indian Thermal Power Stations

10.9.2 Technological necessities of life extension in Indian TPS

10.9.3 Study of major components for residual life assessment

186-215

10.9.4 Futuristic Engineering innovations in uprating and renovating Indian power capacity

10.10 Futuristic Energy Efficient Steam Generation Technologies for Thermal Power Station

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10.10.1 Integrated Coal Gasification Combined Cycle Plants 10.10.2 Futuristic Technologies

10.10.3 Magneto Hydero-Dynamics power generation system 10.10.4 Fluidised Bed Combustion Boiler

10.10.5 Once Through Boilers (OTB) 10.10.6 Tower Types Boilers (TTB) 10.11 Conclusions

XI SUMMARY OF CONCLUSIONS AND RECOMMENDATION 215-219

RELEVANT REFERENCES 220-229

BIODATA 230