Thermal power plant

This presentations contains the basic layout of a thermal power palnt along with the components.Coal and it's types.Future of thermal power plant in India.

1. NETAJI SUBHAS ENGINEERING COLLEGE THERMAL POWER PLANT

2. WHAT IS THERMAL POWER PLANT…?

3. CONTENTS: 1. Introduction 2. Power plant layout 3. Main and Auxiliary Equipment 4. Classification of coal 5. Efficiency of a Thermal p ower plant 6. India’s biggest Thermal power plants 7. Advantages and Disadvantages 8 . Future of Thermal power plant in India

4. Thermal power plant A  Thermal power plant  is a power plant  in which heat energy is converted to Electric  power. In most of the places in the world the turbine is steam-driven. Water is heated, turns into steam and spins a steam turbine which drives an Electrical generator . A Thermal Power Plant converts the heat energy of coal into electrical energy. Coal is burnt in a boiler which converts water into steam. The expansion of steam in turbine produces mechanical power which drives the alternator coupled to the T urbine. Thermal Power Plants contribute maximum to the generation of Power for any country . Thermal Power Plants constitute 60% of the total installed captive and non captive power generation in India . In thermal generating stations coal, oil, natural gas etc. are employed as primary sources of energy.

5. General Layout of Thermal Power Plant

6. 1. Cooling tower. 2. Cooling water pump. 3. Transmission line (3-phase). 4. Unit transformer (3-phase). 5. Electric generator (3-phase). 6. Low pressure turbine. 7. Condensate extraction pump. 8. Condenser. 9. Intermediate pressure turbine. 10. Steam governor valve. 11. High pressure turbine. 12. Deaerator . 13. Feed heater. 14. Coal conveyor. 15. Coal hopper. 16. Pulverised fuel mill. 17. Boiler drum. 18. Ash hopper. 19. Superheater . 20. Forced draught fan. 21. Reheater . 22. Air intake. 23. Economiser . 24. Air preheater. 25. Precipitator. 26. Induced draught fan. 27. Chimney stack. 28. Feed pump. Typical Layout of Thermal power plant with all the Equipments

7. MAIN AND AUXILIARY EQUIPMENTS 1 . Coal handling plant 2. Pulverizing plant 3. Draught fans 4. Boiler 5. Ash handling plant 6. Turbine 7. Condenser 8. Cooling towers and ponds 9. Feedwater heater 10. Economiser 11. Superheater and Reheater 12. Air preheater

8. Coal Handling Plant •The function of coal handling plant is automatic feeding of coal to the boiler furnace. •A thermal power plant burns enormous amounts of coal. •A 200MW plant may require around 2000 tons of coal daily

9. PULVERISING PLANT In modern thermal power plant , coal is pulverised i.e. ground to dust like size and carried to the furnace in a stream of hot air. Pulverising is a means of exposing a large surface area to the action of oxygen and consequently helping combustion. Pulverising mills are further classified as: 1.Contact mill 2.Ball mill 3 .Impact mill

10. DRAUGHT SYSTEM • The circulation of air is caused by a difference in pressure, known as Draught . • Draught is a differential pressure b/w atmosphere and inside the boiler. • It is necessary to cause the flow of gases through boiler setting • It may be – 1 . Natural draught 2 . Artificial draught

11. BOILER • A boiler or steam generator is a closed vessel in which water under pressure, is converted into steam. • It is one of the major components of a thermal power plant • Always designed to absorb maximum amount of heat released in the process of combustion Boilers are of two types- 1 .Fire tube boiler 2 .Water tube boiler

12. SUPERHEATER AND REHEATER Superheater : A Superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheaters are used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming .

13. Reheater : Power station furnaces may have a reheater section containing tubes heated by hot flue gases outside the tubes. Exhaust steam from the high-pressure turbine is passed through these heated tubes to collect more energy before driving the intermediate and then low-pressure turbines.

14. STEAM TURBINE A steam turbine converts thermal energy of steam into mechanical energy and drives the generator. It uses the principle that steam when issuing from a small opening attains a high velocity. This velocity attained during expansion depends on the initial and final heat content of the steam. This difference b/w initial and final heat content repesents the heat energy converted into kinetic energy. These are of two types :-  Impulse turbine  Reaction turbine

15. ASH HANDLING PLANT The percentage of ash in coal varies from 5% in good quality coal to about 40% in poor quality coal Power plants generally use poor quality of coal , thus amount of ash produced by it is pretty large A modern 2000MW plant produces about 5000 tons of ash daily The stations use some conveyor arrangement to carry ash to dump sites directly or for carrying and loading it to trucks and wagons which transport it to the site of disposal.

16. CONDENSER A surface condenser is a commonly used term for a water-cooled shell and tube heat exchanger installed on the exhaust steam from a steam turbine in thermal power stations. These condensers are heat exchangers which convert steam from its gaseous to its liquid state at a pressure below atmospheric pressure.

17. COOLING TOWERS AND PONDS ● A condenser needs huge quantity of water to condense the steam . ● Typically a 2000MW plant needs about 1500MGallon of water. ● Most plants use a closed cooling system where warm water coming from condenser is cooled and reused ● Small plants use spray ponds and medium and large plants use cooling towers . ● Cooling tower is a steel or concrete hyperbolic structure having a reservoir at the base for storage of cooled water ● Height of the cooling tower may be 150 m or so and diameter at the base is 150 m

18. FEEDWATER HEATER A feedwater heater is a power plant component used to pre-heat water delivered to a steam generating boiler. Preheating the feedwater reduces the irreversibility involved in steam generation and therefore improves the thermodynamic efficiency of the system.

19. ECONOMISER Flue gases coming out of the boiler carry lot of heat. An economiser extracts a part of this heat from flue gases and uses it for heating feed water. This use of economiser results in saving coal consumption and higher boiler efficiency.

20. AIR PREHEATER After flue gases leave economiser , some further heat can be extracted from them and used to heat incoming heat. Cooling of flue gases by 20 degree centigrade increases the plant efficiency by 1%. Air preheaters may be of three types Plate type Tubular type Regenerative type

21. Classification of Coal Peat Lignite Sub bituminous Bituminous Semi bituminous Semi Anthracite Anthracite

22. Efficiency of a Thermal power Plant The energy efficiency of a conventional thermal power station, considered salable energy produced as a percent of the heating value of the fuel consumed, is typically 33% to 48%. As with all heat engines, their efficiency is limited, and governed by the laws of thermodynamics.

23. India’s Biggest Thermal power plants 1.Vindhyachal Thermal Power Station, Madhya Pradesh Vindhyachal Thermal Power Station in the Singrauli district of Madhya Pradesh, with an installed capacity of 4,760MW, is currently the biggest thermal power plant in India. It is a coal-based power plant owned and operated by NTPC.

24. 2.Mundra Thermal Power Station The 4,620MW Mundra Thermal Power Station located in the Kutch district of Gujarat is currently the second biggest operating thermal power plant in India. It is a coal-fired power plant owned and operated by Adani Power.

25. 3.Mundra Ultra Mega Power Plant (UMPP) The 4,000MW Mundra Ultra Mega Power Plant (UMPP), also located in the Kutch district of Gujarat, ranks as the third largest thermal power plant in India. It is a coal-fired power plant owned and operated by Coastal Gujarat Power Limited (CGPL), a subsidiary of Tata Power.

26. Advantages: ●Very Cheap ● Less Space Compared to Hydro Power Station ● Capital Cost Rs . 3 – 4 Cr /MW ● Located at Load centers ● Quick response to Load Variations Disadvantages : ● High Maintenance ● High Pollution ● Ash Disposal ● Long time- (Erection & Installation) ● High Operating Cost

27. Future of Thermal power plant in India CEA(Central Electricity Authority ) says that around 50,000 MW of coal power plants is under construction which would be most likely beneficial for the period 2017–2022 and fulfill the demand in the 5 year period 2022–27 . The report also says that the share of renewable energy would be around 20% in 2021–22 and 24.6% in 2026–27 . Older units are most likely to be replaced by super-critical units . The target for renewable energy addition by 2022 has been revised to 175GW(1,75,000MW) and that’s a huge task and would require huge investments . KOLKATA: Coal-fired power generation is expected to grow 4.05 per cent during 2017-18, suggests Central Electricity Authority (CEA) in its latest estimates. Hydel on the other hand is expected to grow 5.52 per cent, while nuclear will grow only about 2.43 per cent during the same year . I think the future of coal based power plants would not be good as we progress and invest more and more in clean energy technologies.

28. Thank You Prabakaran Sir for guiding us patiently. Soham Sir for your timely inputs and support whenever we needed.