Bandel training

a presentation where we did our vocational winter training.

1. BANDEL THERMAL POWER STATION(BTPS) TRAINING PROJECT BY SUBHADIP SADHUKHAN ELECTRICAL 3 RD YEAR TEZPUR UNIVERSITY , ASSAM

2. POWER PLANT OPERATING UNITS 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.  Feedwater 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 pulverizer 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

3. POWER PLANT SCHEMATIC DIAGRAM

4. A  Rankine cycle  with a two-stage  steam turbine  and a single feed water heater.

5. BANDEL THERMAL POWER STATION OVERVIEW:- Situated on the west­ern bank of Bhagirathi River, Bandel Ther­mal Power Sta­tion is just 1 Km from the Assam Road and con­nected with a heavy duty metal lead road 3 km off the Grand trunk Road, NH2. Bandel Ther­mal Power Station’s near­est rail­head is Tribeni on the Bandel-​Katwa-​Azimgunj Line under East­ern Railways. Successfully meet­ing the power sec­tor demand for the State for more than four decades, Bandel Ther­mal Power Sta­tion still remains a promi­nent player in the states power supply chain. Bandel Ther­mal Power Station’s fifth unit with a capac­ity of 210 MW installed in 1982, was first of its kind in East­ern India & fifth in India. Today, with five oper­a­tional units the total installed capac­ity of the sta­tion stands at 450 MW. SI NO UNITS CAPACITY(MW) 1 UNIT-I 60 2 UNIT-II 60 3 UNIT-III 60 4 UNIT-IV 60 5 UNIT-V 210 TOTAL CAPACITY- 450 UNIT SYNCHRONISATION COD 1 04.09.1965 04.09.1965 2 18.10.1965 18.10.1965 3 17.02.1966 17.02.1966 4 03.08.1966 03.08.1966 5 08.10.1982 20.03.1983

6. WHAT IS THERMAL POWER PLANT ? A thermal power station is a power station 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,& it turns into steam and spins a steam turbine which drives an electrical alternator. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was heated; this is known as a Rankine cycle. The greatest variation in the design of thermal power stations is due to the different heat sources; fossil fuel dominates here, although nuclear heat energy and solar heat energy are also used. Some prefer to use the term energy centre because such facilities convert forms of heat energy into electrical energy. Certain thermal power stations are also designed to produce heat energy for industrial purposes, or district heating, or desalination of water, in addition to generating electrical power.

7. MAIN & AUXILIARY COMPONENTS : Coal handling plant. Pulverizing plant. Draft fans. Boiler. Ash handling plant. Turbine. Condenser. Cooling towers & ponds. Feed water heater. Economiser. Superheater & reheater. Air preheater.

8. 1.COAL HANDLING PLANT The function of coal handling plant is automatic feeding of coal to the boiler furnace. Coal handling plant consists of a few systems- Coal. Unloading system. Conveyor system. Crushing system. Feeding system. Stacking system. Magnetic separator/metal detector. Bin/chute vibratory system. Coal weighment. Coal sampling. Fire fighting system. Dust suppression system. Dust extraction system.

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

10. 3.DRAFT SYSTEM The circulation of air is caused by a difference in pressure , known as draft. Draft is differential pressure between atmosphere & inside the boiler . It is necessary to cause the flow of gases through the boiler setting . It may be – Natural draft. Mechanical draft.

11. 4.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 the thermal power plant . It is 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.

12. 5.SUPERHEATERS & REHEATERS Most of the modern boilers are having superheater & reheater arrangement. SUPERHEATERS: Superheater is a component of a steam-generating unit in which steam , after it has left the boiler drum , is heated above its saturation temperature. The amount of superheat is added to the steam is influenced by the location , arrangement, & amount of superheater surface installed , as well as the rating of the boiler. The superheater may consist of one or more stages of tube banks arranged to effectively transfer heat from the products of combustion. Superheaters are classified as convection , radiant or combination of these. REHEATERS: Some of the heat of the superheated steam is used to rotate the turbine where it loses some of its energy. Reheater is also steam boiler component in which heat is added to this intermediate-pressure steam , which has given up some of its energy in expansion through the high-pressure turbine. The steam after reheating is used in to rotate the second steam turbine where the heat is converted to mechanical energy. This mechanical energy is used to run the alternator , which is coupled to turbine , thereby generating electrical energy.

13. 6.TURBINE A steam turbine converts heat energy of steam into mechanical energy & 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 initial & final heat content of the steam. T his difference between initial & final heat content represents the heat energy converted into kinetic energy . These are of two types- Impulse turbine. Reaction turbine.

14. 7.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 coal, thus amount of ash produced by it is pretty large. The stations use some conveyor arrangement to carry ash to dump sites directly for carrying & loading it to trucks & wagons which transport it to the site of disposal.

15. 8.CONDENSER Steam after rotating steam turbine comes to condenser. Condenser refers here to the shell & tube heat exchanger(or surface condenser)installed at the outlet of every steam turbine in Thermal power stations of utility companies generally. These condensers are heat exchangers which convert steam from its gaseous state to its liquid state, also known as phase transition. In so doing, the latent heat of steam is given out inside the condenser. The purpose is to condense the outlet(or exhaust) steam from steam turbine to obtain maximum efficiency & also to get the condensed steam in the form of pure water, otherwise known as condensate, back to the steam generator or (boiler)boiler feed water.

16. 9.COOLING TOWERS & PONDS A condenser needs huge quantity of water to condense the steam. Most plants use a closed cooling system where warm water coming from condenser is cooled & reused. Small plants use spray ponds & medium & 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.

17. 10.FEED WATER HEATER Advantages of heating water before feeding back to the boiler- Feed water heating improves overall plant efficiency. The dissolved oxygen & carbon dioxide which would otherwise cause boiler corrosion are removed in feed water heater. Thermal stresses due to cold water entering the boiler drum are avoided. Quantity of steam produced by the boiler is produced. Some other impurities carried by the steam & condensate, due to corrosion of boiler & condenser are precipitated outside the boiler. Hence we use feed water heater.

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

19. 12.AIR PREHEATER After flue gases leave economiser, some further heat can be extracted from them & used to heat incoming water. 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.

20. BIBLIOGRAPHY B andel thermal power station. www.google.com www.slideshare.com www.scribd.com