Industrial training at NTPC Shaktinagar

Industrial training report

1. INDUSTRIAL TRAINING AT NATIONAL THERMAL POWER STATION Singrauli , Madhya Pradesh Submitted By: Rishikesh (11-1-6-002) NIT, Silchar

2. In this Presentation Introduction Power plant layout Coal to Electricity Basics Main and Auxiliary Equipments . Combustion Process Power Plant Cycle Boilers. Burner Management System

3. Introduction 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 turbine . Thermal Power Plants contribute maximum to the generation of Power for any country . Thermal Power Plants constitute 75.43% 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 .

4. General Layout of Thermal Power Station

5. Diagram of a typical coal-fired thermal power station 1. Cooling tower 10. Steam Control valve 19. Superheater 2. Cooling water pump 11. High pressure steam turbine 20. Forced draught (draft) fan 3. transmission line (3-phase) 12. Deaerator 21. Reheater 4. Step-up transformer (3-phase) 13.  Feed water heater 22. Combustion air intake 5. Electrical generator (3-phase) 14. Coal conveyor 23. Economiser 6. Low pressure steam turbine 15. Coal hopper 24. Air preheater 7. Condensate pump 16. Coal pulveriser 25. Precipitator 8. Surface condenser 17. Boiler steam drum 26. Induced draught (draft) fan 9. Intermediate pressure steam turbine 18. Bottom ash hopper 27. Flue gas stack

6. Coal to Electricity ….. Basics Coal Chemical Energy Super Heated Steam Pollutants Thermal Energy Turbine Torque Heat Loss In Condenser Kinetic Energy Electrical Energy Alternating current in Stator Mech. Energy Loss ASH Heat Loss Elet . Energy Loss

7. Main and Auxiliary equipments Coal handling plant Pulverizing plant Draft fans Boiler Ash handling plant Turbine Condenser Cooling towers and ponds Economiser Superheater and Reheater Air preheater

8. Coal handling plant and Pulverizing 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. Coal is conveyed through rail wagon from out side of plant Through conveyor system collected in hopper and ground to a very fine powder by large metal spheres in the pulverized fuel mill . Pulverizing is a means of exposing a large surface area to the action of oxygen and consequently helping combustion. A 200MW plant may require around 2000 tons of coal daily

9. Draft system The circulation of air is caused by a difference in pressure, known as Draft . Forced Draft fan use to feed pulverized coal to boiler Induced Draft fan use to maintain the flow of flue gases in the boiler. Forced Draft Fan Induced Draft Fan

10. 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- Fire tube boiler Water tube boiler

11. Superheater and Reheater Superheater is a device used to convert saturated steam or wet steam into dry steam. Output steam is called Superheated steam and the temperature is 540 Celsius. Superheated steam used to rotate HP turbine. Some of the heat of superheated steam is used to rotate the turbine where it loses some of its energy. Reheated is added a heat to that steam. The steam after reheating is used to rotate the second steam turbine where the heat is converted to mechanical energy.

12. BOILER FEED PUMP Feed deoxygenated water to the boiler drum through economizer. SOLE PLATE (BASE PLATE) SLEEVE DE BEARING DE BEARING

13. DE AREATOR A deaerator is a device that is widely used for the removal of air and other dissolved gases from the feed water to steam-generating boiler. The condensed water is then passed by a feed pump through a deaerater .

14. Turbine A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion .

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

16. CONDENSER Water Cooled Condenser Air Cooled Condenser Condenser is a device or unit used to condense a substance from its gaseous to its liquid state, typically by cooling it. The exiting steam from steam turbine, now a little above its boiling point, is brought into thermal contact with cold water (pumped in from the cooling tower) in the condenser. where it condenses rapidly back into water, creating near vacuum-like conditions inside the condenser chest.

17. HPH 5 PSH ECO HPH6 FSH LTSH DRUM FURNACE IPT LPT HPT R/H LPH 1 GSC LPH2 LPH3 DEA D/C COND CONDENSATE CYCLE

18. 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

19. Economiser Economizer are mechanical devices intended to reduce energy consumption, or to perform another useful function like preheating a fluid . 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. Rankine Cycle Adiabatic Expansion in Turbine Constant Pressure Heat Rejection in Condenser Pump Work Sensible heat Addition in Economizer ENTROPY TEMPERATURE Latent Heat Addition in Evaporator (constt. Pressure) Super Heating L + V

22. Boiler

23. Boiler Temperature Measurement Expansion of Solids Thermostats Expansion of Liquids Temperature Gauges Expansion of gases Temperature Gauges Thermal Electricity Thermocouples Type K Chromel Alumel etc. Change of Electric Resistance (RTD) Pt100 Cu53 Intensity of total radiation Optical Pyrometer Radiation Pyrometer

24. Burner management system Burner management system is designed to ensure the execution of a safe ,orderly operating sequence in the startup and shutdown of fuel firing equipments and to prevent errors of omission safe operating procedure. Function of BMS TO PROVIDE SAFETY TO BOILER . TO PROVIDE ORDERLY SEQUENCE IN THE S/U & S/D OF FUEL FIRING EQUIPMENTS . CONTINUOUS FLAME MONITORING . MAINTAIN THE APPROPRIATE TEMPERATION AND AIR PRESSURE INSIDE THE BURNER Prevent firing unless a satisfactory furnace purge has first been completed.

25. THANK YOU