Transcript ENERGY CONSERVATION IN THERMAL POWER STATION
ENERGY CONSERVATION IN THERMAL POWER STATION Engineering Staff College, Hyderabad 10th December, 2002
Key Note Address
by
K. SREERAMA MURTHY,
Member, APERC, HYD
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ENERGY CONSERVATION IN THERMAL POWER STATION
Government of India established a dedicated group within the National Productivity Council (NPC) to address energy efficiency issues in various sectors. NPC achieved considerable success towards developing awareness of energy conservation and its improvement.
One of the key initiatives taken by GOI include (Energy Conservation Act, 2001).
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ENERGY CONSERVATION IN THERMAL POWER STATION ENERGY CONSERVATION ACT, 2001
Energy Conservation Act passed in the Parliament August 2001 and Gazetted in October 2001.
in Mandatory energy audit for the energy intensive industries by an accredited energy auditor.
Development of norms and benchmarks for energy energy intensive industries.
in Bureau of energy efficiency (BEE) was created to be the primary implementing agency.
Energy Management Centre, Ministry of Power merged with BEE.
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ENERGY CONSERVATION IN THERMAL POWER STATION
THERMAL POWER STATIONS ARE THE MOST ENERGY INTENSIVE INDUSTRY
Cost of fuel (input energy) is 85% of the total operating costs.
8 to 10% of final output (electrical energy) is consumed for its own auxiliaries.
Due to the above, energy efficiency issues are of the highest priority in Thermal Power Station.
Energy Audit becomes Conservation Act, 2001.
mandatory under Energy
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ENERGY CONSERVATION IN THERMAL POWER STATION
Functions of the newly constituted BEE as per the EC Act 2001 are: Recommend to the Central Government the norms for processes ad energy consumption standards.
Promote use of energy efficient processes, equipment, devices and systems Promote innovative financing of energy efficiency projects.
Maintain a list of accredited energy auditors as may be specified by regulations.
Specify, by regulations, qualifications for the accredited energy auditors.
Specify, by regulations, the manner and intervals of time in which the energy audit shall be conducted.
Specify, by regulations, certification procedures for energy managers to be designated or appointed by designated consumers.
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ENERGY CONSERVATION IN THERMAL POWER STATION ENERGY AUDIT (EC ACT, 2001)
Energy audit means the verification, monitoring and analysis of use of energy including submission of technical report containing recommendations for improving energy efficiency with cost benefit analysis and an action plan to reduce energy consumption.
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ENERGY CONSERVATION IN THERMAL POWER STATION Energy Service Company (ESCO)
An ESCO, or Energy Service Company, is a business that develops, installs, and finances projects designed to improve the energy efficiency and maintenance costs for facilities over a seven to 10 years time period. ESCOs generally act as project developers for a wide range of tasks and assume the technical and performance risk associated with the project.
Develop, design, and finance energy efficiency projects; Install and maintain the energy efficient equipment involved; Measure, monitor, and verify the project's energy savings; and Assume the risk that the project will save the amount of energy guaranteed.
These services are bundled into the project's cost and are repaid through the money savings generated.
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Need for End-use Energy Efficiency: Maximising system-wide benefits
Generation Improvement potential 10% Total potential - 60% Non Technical losses 20% HT Transmission Customer Lt Distribution Inefficient end use 20% I 2 R Losses 10%
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WHY ENERGY EFFICIENCY (EE)?
“Negawatts” win over “Megawatts”
Economic Perspective (National and/or supplier) EE (or Negawatts) are cheaper than Megawatts.
EE provides maximum system wide benefits.
EE reduces need for imports & scarce resources.
EE mitigates risk from supply vulnerabilities.
Customer Perspective: Utilities come closer to customers, better control.
Supply quality and reliability improvements.
Lowers impact of tariff rationalization / increase.
Societal Perspective: Environmental benefits (emissions and wastes)
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ENERGY CONSERVATION IN THERMAL POWER STATION Comparison between a Typical and most Indian Power Utilities
Performance Station use Frequency fluctuations Voltage fluctuations Statistical no-availability Thermal efficiency Technical Transmission & Distribution losses Commercial losses Financial standing Typical 6% - 8% 0.2 Hz India 6% - 12% 2 Hz 5% - 7% 0.1 hours per year 10% - 40% About 200 - 800 hours/year 43% 7% - 9% from 440 Kv to 37% (because of bad coal) Estimated 30% from 220 KV 220 V (entire national to 220 V grid) <1% >20% Profitable Technically Bankrupt
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ENERGY CONSERVATION IN THERMAL POWER STATION
Efficiency Improvement Opportunities Average 1.5% increase in effeciency of Thermal Power Plants in India could result in: CO 2 reduction: 4.5% per annum (over 10 Millon Ton/ annum) Coal savings: 9 Million tons per annum Coal savings worth Rs. 630 Crore Higher productivity from same resources; equvalent to capacity addition.
Lower generation cost per KWh.
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ENERGY CONSERVATION IN THERMAL POWER STATION ENERGY BALANCE OF 500 MW PLANT UNIT
% MW Heat input to boiler Boiler losses Steam & feed range radiation losses Condenser loss TG set Elec. & Mech. Losses Works Auxiliaries Generator output 100 9.5
0.5
52.5
1.5
1 35 1428 137 7 750 20 14 500
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ENERGY CONSERVATION IN THERMAL POWER STATION EFFICIENCY OF VARIOUS IDEAL CYCLES
Basic Rankine Cycle Cycle with superheat Cycle with reheat Cycle with superheat and feedheating Cycle with reheating and feedbeating Carnot Cycle 41.40% 45.80% 47.50% 52.00% 53.20% 52.10%
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ENERGY CONSERVATION IN THERMAL POWER STATION Typical values of the normally calculated boiler losses for a PF-fired boiler Loss
Dry flue gas Wet flue gas Sensible heat in water vapour Combustible in ash Radiation and unaccounted Total loss Boiler efficiency = (100% - losses)
GCV v% NCVp %
4.00
4.30
5.25
0.75
0.25
0.45
9.95
90.05
0.25
0.46
5.76
94.24
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ENERGY CONSERVATION IN THERMAL POWER STATION
Heat values of carbon and hydrogen in kJ/kg Hydrogen Carbon to CO Carbon to CO2
GCV v NCVp
143 050 121 840 10 200 33 820 -
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ENERGY CONSERVATION IN THERMAL POWER STATION Efficiency Improvement - Boiler & Auxiliaries
Boiler Performance Testing & Optimization: Balancing of coal and air flow in coal pipes of each mill.
Air heater performance testing.
Combustion regime evaluation to ascertain level of combustion completion and uniformity of heat release.
Evolving an optimum boiler operating regime by testing boiler under different conditions.
Assessment of reasons for loss of draft margins.
Confirming accuracy of online oxygen monitor.
Feedback from these tests is used to cross-check the 'on line' station instruments and to plan the work to be undertaken during next overhaul.
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ENERGY CONSERVATION IN THERMAL POWER STATION ENERGY EFFICIENT MEASURES IN T.P.S.
Factors during the design stage: (1) Highest steam parameters particulars the (2) (3) (4) (5) (6) temperature.
Reducing exhaust pressure.
Regenerative feed heating.
Improvements in combustion.
Improvements in turbine blade design.
Improvements in alternator performance including the improved cooling systems.
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ENERGY CONSERVATION IN THERMAL POWER STATION
ENERGY EFFICIENT MEASURES DURING OPERATION Factors during operation - Boiler: (1) (2) (3) Control of excess air.
Control of fireness of pulverised fuel.
Keeping heat transfer areas clean - soot blowing.
(4) (5) (6) Keeping the tramp air (air leakage) to minimum.
Control of flue gas temperature leaving the stack.
Optimising the auxiliaries consumption.
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ENERGY CONSERVATION IN THERMAL POWER STATION
ENERGY EFFICIENT MEASURES DURING OPERATION Factors during operation - Turbo-Generator: (1) Controlling the throttle losses.
(2) (3) (4) (5) Optimising condenser performance.
Optimising feed heaters performance.
Optimising auxiliaries consumption.
Reduction in make-up water consumption.
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ENERGY CONSERVATION IN THERMAL POWER STATION
The energy consumption in the driving equipment of the auxiliaries is as follows:
Boiler Feed Pumps I.D. Fans Circulating water pumps Mills Primary air fans Forced draft fans Other motors 30.8% 17.8% 16.4% 10.5% 7.0% 6.9% 10.6%
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