Heat Rate Improvement Guidelines
for
Indian Power Plants
Volume I
By:
United States Tennessee Valley Authority
In Association With
Nationall Thermal Power Corporation Ltd.
For:
United States Agency for Internationall Development and
National Energy Technology Laboratory,
United States Department of Energy
Project Funded by:
USAIDIIndia Greenhouse Gas Pollution Prevention Project (GEP)
Heat Rate Improvement Guidelines
for
Indian.Power Plants
Volume I
Revision 1 June 2000
Principal Author:
Robert J. Tramel
TVA 'sParticipation Under:
DOE Interagency Agreement No. DE-AI26-97FT97300
'TVA" is a registered trademark ofthe TennesseeValley
Authority
PREFACE
This report is both an ending, and a beginning. It is the culmination of a several year long partnership between the United States Tennessee Valley Authority (TVA) and the Government of India's National Thermal Power Corporation (NTPC). This partnership was formed to transfer proven and economically feasible technology on improving thermal performance (heat rate) of coal fired power plants, to the Indian power sector. These improvements reduce the amount of coal burned per unit of generation, thereby resulting in reduced emissions to the environment, including carbon dioxide (C02).
This report is also a beginning, as its purpose is to document and disseminate to all utilities in India the knowledge that has been demonstrated and proven during this partnership. TVA and NTPC have worked together to transfer procedures, software, skills and technology that are used in the United States to maintain and improve the heat rate of plants there, and to demonstrate their validity in India. This report documents this information. It includes procedures on monitoring, testing, documenting losses, training, typical areas where improvements can usually be made with minimal cost, recommendations for new plant specifications, and how to most efficiently dispatch multiple units.
The origins of this project go back to 1992, and the United Nation's Framework Convention on Climate Changes (FCCC) that was held in Rio-de-Janeiro. As a result of this conference, a fbnding mechanism for environmental protection called Global Environmental Facility (GEF) was established. The Greenhouse Gas Pollution Prevention Project (GEP) represents the United States commitment to GEF. The purpose of the project is to reduce COz emissions per kwh of electricity produced by improved efficiency of coal fired thermal plants. In 1994, a protocol of intent was signed between the United States and the Government of India. The GEP project has two components, the Alternative Bagasse Cogeneration (ABC) component and the Efficient Coal Conversion (ECC) component.
The National Thermal Power Corporation of India (NTPC) was selected as the implementing agency for the ECC component of the GEP project. NTPC created the Centre for Power Efficiency and Environmental Protection (CenPEEP), to address efficiency and environmental improvements at power stations of NTPC and various State Electricity Boards (SEBs). The United States Agency for International Development (USAID) entered into an agreement with the US Department of Energy (DOE) National Energy Technology Laboratory (NETL) to implement the ECC component with NTPC. In October 1995, the Tennessee Valley Authority, the largest utility in the United States, whose heat rates are historically among the best in the US, began work on this task, under the direction of DOE and USAID.
Some of the major activities that have been carried out during this multiyear program include:
Performance testing (resulting in recommendations for improvements) at NTPC's Dadri, Singrauli, and Rihand plants; Gujarat SEB's Wanakbori plant and Maharashtra SEB7sKoradi plant including :
t Pulverizer
t Burner Balancing
t Boiler Cycle Optimization t Feedwater Heaters
+HP / IP Turbines t Condensers
+Pumps
t Turbine Cycle
Transfer of and training on, high accuracy performance test equipment Training at US power plants and corporate offices for 11 NTPC personnel Walkdowns and recommendations for heat rate improvements at several plants.
Demonstration of new condenser tube cleaning techniques
Demonstration of new techniques for locating sources of condenser air inleakage
Training on thermal modeling software
Training seminars and workshops on subjects such as pulverizer optimization, condenser performance, and variable pressure operation
The culmination of these activities, and additional activities carried out independently by CenPEEP, has made a significant impact on the thermal efficiency and COZemissions in Indian power plants.
ACKNOWLEDGMENTS
The work that culminated in this report would not have been possible without the assistance and cooperation of many persons and organizations. For several years, many individuals extended every courtesy and provided valuable support. Without their hard work, encouragement and help, this project could not have been successhlly completed. Below is a partial list of the people to whom I am indebted:
United States Agency for International Development (USAID)
Richard G. Goldman, Director (former), Office of Environment, Energy and Enterprise
Richard E. Edwards, Director, Ofice of Environment, Energy and Enterprise
Kavita Sinha, Project Specialist, OEce of Environment, Energy and Enterprise
United States Department of Energy (USDOE)
Gary Staats, Resident Advisor, National Energy Technology Laboratory Suresh Jain, Resident Advisor, National Energy Technology Laboratory
Science Applications International Corporation (SAIC)
Radha P. Krishnan, Technical Advisor, USAIDAndia Coal Projects
National Thermal Power Corporation, Ltd. (NTPC)
B. N. Ojha, Director (Operations)
NTPC Centre for Power Efficiency and Environmental Protection (CenPEEP) L.M. Kapoor, General Manager
P.C. Saha, Additional General Manager
S. C. Deo Sharma, Deputy General Manager D. K. Agrawal, Deputy General Manager S. Kapoor, Deputy General Manager
B. M. Singh, Deputy General Manager Pankaj Bhartiya, Senior Manager
L. M. Rastogi, Senior Manager A. K. Mittal, Senior Manager Ved Prakash, Senior Manager A. K. Arora, Manager
0.P. Agnihotri, Manager
M. K. S. Kutty, Manager
NTPC National Capital Power Project (NCPP Dadri)
G. P. Singh, General Manager
K. Krishnamurthy, Deputy General Manager (O&M)
D. K. Bhattacharya, Deputy General Manager (Op)
S. Sankaran, Senior Superintendent (O&M-O&E)
M. Pai, Senior Superintendent (O&M-Th)
Shaswattham, Deputy Manager (O&E)
NTPC Singrauli Super Thermal Power Station (SSTPS)
S. D. Deshpande, Additional General Manager
Y.Singh, Senior Superintendent (Effcy) R. N. Pandey, Superintendent (Em
NTPC Rihand Super Thermal Power Project (RSTPP) R. S. Sharma, General Manager
J. Jha, Deputy General Manager (O&M) Thomas Joseph, Deputy General Manager (Opm) Surendra Prasad, Superintendent (O&E)
Gujarat Electricity Board, (GSEB) Wanakbori Thermal Power Station (WTPS) H. I. Patel, Chief Engineer
S. N. Pancholi, Chief Engineer
R. B. Chowksi, Superintendent (O&E)
Maharashtra State Electricity Board, (MSEB) S.D.Mahajan, CE (Gen Works), Mumbai C.S. Dongre ,CE (Gen)TI&C, Nagpur V.A.Joshi, Sr.EE ,Nagpur
S.N. Joshi , CE (Gen O&M), Koradi Thermal Power Station R.P.Chitore ,Dy.CE, Koradi Thermal Power Station N.K.Gavshinde, SE(Gen), Koradi Thermal Power Station A.R.Kulkarni, SE, Koradi Thermal Power Station A.M.Bopche ,Dy.EE, Koradi Thermal Power Station
United States Tennessee Valley Authority (TVA)
Edmund A Kopetz, Manager, Technical Services Charlie L. Breeding, Manager Field Testing Services
Carolyn B. Marvil, Manager Thermal and Reliability Support Rex C. Helton, Principal Engineer
William W. Oberg, Principal Engineer H. Eric Sikes, Senior Engineer Timothy P. Gaither, Senior Engineer Robert C. Egli, Senior Engineer Linda S. Schaefer, Contract Agent
EXECUTIVE SUMMARY
This guideline documents the various components of a heat rate improvement program. The activities described here apply to any power plant, from small units (<100MW) to large plants. They also apply to both newer units and to older units. The components of the heat rate improvement program listed here have been success~llyimplemented in the United States and have now been demonstrated in the Indian power sector.
Key Points:
Heat rate improvements are possible at any plant, and at many plants the improvement can easily be in the range of 1-2 percentage points.
A heat rate improvement program can start small, concentrating on one or two areas, (i.., condenser performance andlor burner balancing) or by concentrating on one or two activities (i.e., monitoring primary process indicators, testing, etc.)
Heat rate improvement must have the full support of the plant management. Improvements do not "just happen", there must be a concerted effort made just to maintain current status, and even more effort expended to make improvements. Each plant should have a detailed plan listing specific activities that are to be carried out to make improvements, and the plan must be reviewed periodically to ensure that the plan is being carried out.
Heat rate improvement is a continuing process. It must become part of the normal work activities, it must be considered along with, and at par with, reliability, safety, environmental concern, etc., when operating the unit, schedulingmaintenance, and all other routine activities.
Heat rate improvement is the responsibility of everyone. It cannot be assigned to one individual or organization, but requires the active involvement of the entire plant staff.
Typical Savings from Heat Rate Improvements (Rupees 1 year)
Plant Location |
Pit Head Station |
Rail Fed Station |
||
Unit Size (MW) |
-210 |
-500 |
-210 |
-500 |
1 % Overall Heat Rate Improvement |
5,518,800 |
13,140,000 |
14,716,800 |
35,040,000 |
(from 2500 kcallkwh) |
|
|
|
|
1% Air Heater Inlet Oxygen |
1,635,772 |
3,894,696 |
4,362,060 |
10,385,856 |
1 mm Hg Condenser Pressure |
448,127 |
1,066,968 |
1,195,004 |
2,845,248 |
1 "C Air Heater Exit Gas Temperature |
264,902 |
630,720 |
706,406 |
1,681,920 |
1 "C Main Steam Temperature |
141,281 |
336,384 |
376,750 |
897,024 |
I "C HRH at Intercept Valve Temperature |
130,244 |
310,104 |
347,316 |
826,944 |
I000 kgthr Reheat Attemporation Flow |
54,305 |
129,298 |
144,813 |
344,794 |
Assumptions :
PLF (96)
Fuel HHV (kcallkg)
Fuel Cost (Rstton)
vii
From the preceding analysis it is evident that even a modest change in the several unit operating parameters can result in substantial savings in fbel cost. Based on the collaborative efforts that were carried out in India on several units, by CenPEEP and TVA it is firmly believed that it is possible to improve the level of performance even in the newest and best performing plants, and that the financial rewards are well worth the time and resources expended in improving heat rate.
TABLE OF CONTENTS
1.Introduction
1.1.Heat Rate Improvement Program
1.1.1.Definition
1.1.2.Purpose
1.1.3.How to Start a Heat Rate Improvement Program
1.1.4.Mistakes to Avoid
1.2.Definitions
1.2.1.Generation
1.2.2.Heat Rate
1.3.Description of Each Section of the Guideline
1.3.1.Section 2 - Monitoring Primary Process Indicators
1.3.2.Section 3 - Calculating Heat Rate Deviations by Parameter
1.3.3.Section 4 - Performance Testing
1.3.4.Section 5 - Heat Rate Action Plan
1.3.5.Section 6 - Tools
1.3.6.Section 7 - Manpower and Training Programs
1.3.7.Section 8 - Heat Rate Surveys and Audits
1.3.8.Section 9 - New Plant Specifications
1.3.9.Section 10 - Carbon Dioxide Emissions
1.3.10.Section 11 - Economic Dispatch of Multiple Units
1.3.11.Section 12 - Common Areas of Heat Rate Improvements
2.Monitoring Primary Process Indicators
2.1.Purpose
2.2.Definition of Primary Process Indicators
2.3.Data Collection and Analysis Methods
2.4.List of Primary Process Indicators
2.5.References
3.Calculating Heat Rate Deviations by Parameter
3.1.Reasons for Tracking Heat Rate Deviationsby Parameter
3.2.What Parameters Should Be Tracked
3.2.1.Turbine Cycle
3.2.2.Boiler Cycle
3.2.3.Auxiliary and Station Power
3.2.4.Unaccountables
3.2.5.Categories of Parameters
3.3.What Baseline Should Be Used 3-3.1. Design
3.3.2.Performance Guarantee Test
3.3-3. Historical Operating or Test Data 3.3.4. Benchmarking Similar Units 3-3.5. Current Expected
3.4.Overview of Methodology
3.5.Data To Be Collected to Set-up the Procedure
3.5.1.Condenser Characteristics Database
3.5.2.Turbine Cycle Database
3.5.3.Boiler Database
3.5.4.Miscellaneous Unit CharacteristicsDatabase
3.5.5.Heat Rate Correction Curves
3.6.Operating Data to Be Collected
3.6.1.Parameter Values
3.6.2.Miscellaneous Values
3.6.3.Data Reduction
3.6.4.Fuel Characteristics
3.7.Detailed Procedures
3.7.1.Develop Reference Heat Rate and Reference Parameter Curves
3.7.2.Generate Heat Rate Correction Factor Curves
3.7.3.Develop Expected Parameter Curves
3.7.4.Calculation of Reference Net Heat Rate
3.7.5.Calculation of Actual Net Heat Rate
3.7.6.General Comments on Calculating Heat Rate Deviations for All Parameters
3.7.7.Air Preheating Coils
3.7.8.Boiler Differential Pressure
3.7.9.Condenser Pressure
3.7.10.Final FW Temperature & HPH Out of Service
3.7.11. Makeup
3.7.12.Reheat Attemporation
3.7.13.Station Service (Prorated) - Idle
3.7.14.Station Service (Prorated) - Operating
3.7.15.HRHat Intercept Valve Temperature
3.7.16.Superheat Attemporation
3.7.17.Throttle Pressure
3.7.18.Throttle Temperature
3.7.19.Turbine Efficiency
3.7.20.Unit Auxiliary Power
3.7.21.Losses That AfTect Boiler Efficiency 3.7.21.1.Boiler Outlet 0 2 3.7.21.2.Combustibles in Ash 3.7.21.3.Exit Gas Temperature 3.7.21.4.Hydrogen in Fuel 3.7.21.5.Moisture in Fuel 3.7.21.6.PulverizerRejects
3.7.22.Expected Net Heat Rate
3.7.23.Unaccountables
3.7.24.Calculation of Cost Due to Heat Rate Deviations
3.8.Example