NTPC Dadri - THERMAL POWER GENERATION

1. Summer Training
At
NTPC (DADRI)
SUBMITTED BY - SUBMITTED TO -
Harsh Kumar Mr. Ajay Kumar
ME - 4th year, Sec.-A ME Deptt.
Roll. No. - 1202940074

2. About NTPC
 NTPC is India’s largest energy conglomerate with roots planted way back in 1975 to
accelerate power development in India.
 NTPC became a Maharatna company in May 2010, one of the only four companies to be
awarded this status.
 NTPC was ranked 431st in the ‘2015, Forbes Global 2000’ ranking of the World’s
biggest companies.
 The total installed capacity of the company is 45,548 MW (including JVs) with 18 coal
based and 7 gas based stations. 7 Joint Venture stations are coal based and 8 renewable
energy projects and 1 hydro project.
 Although the company has 17.73% of the total national capacity, it contributes 25.91%
of total power generation due to its focus on high efficiency.

3. INSTALLED CAPACITY
S.No. NO. OF PLANTS CAPACITY (MW)
NTPC Owned
Coal 18 34,425
Gas/Liquid Fuel 7 4,017
Hydro 1 800
Renewable energy
projects
8 110
Total 34 39,352
Owned By JVs
Coal & Gas 7 6,196
Total 41 45,548

4. NTPC - Dadri
TOTAL CAPACITY OF DADRI POWER PLANT :-
(A) THERMAL (B) GAS
 I:- 04X210 MW = 840 MW I:- 04X130.19
 II:- 02X490 MW = 980 MW II:- 02X154.51
TOTAL = 1820 MW TOTAL = 817 MW
(C) SOLAR = 05MW
GRAND TOTAL = 2642 MW

5. SOURCES
 Coal source
- Piparwara mine , Jharkhand
- Requirement = 13000 MT/day
 Water source
- Upper Ganga Canal
 Gas source
- HBJ Pipeline (a major gas pipeline of GAIL)
Hazira-Bijaipur-Jagdishpur

6. Layout of a typical coal fired thermal power station

7. Basic Working of Thermal Power Plant

8. Working of a Thermal Power Plant
 The coal is brought and crushed to powder. This is feed to boiler for producing heat .
 In Boiler the water is converted to steam.
 In Superheater the moisture content is removed from the steam and that steam is called super heated
steam.
 The superheated steam rotates the shaft of the High Pressure(HP) turbine.
 The exhausted steam is sent to Reheater and the steam then rotates the Intermediate Pressure (IP)
turbine.
 The steam from the IP Turbine is then feed to Low Pressure(LP) turbine.
 The turbine shaft is connected to the Generator, which produces electric power.
 The steam expanded in turbine is condensed in a Condenser to be feed into the boiler again.

9. Basic Power Plant Cycle

10. COAL HANDLING PLANT
Raw coal wagon – Coal is brought to the site
through a wagon as per the requirement.
Wagon tippler – The coal is unloaded from the
wagon and is transported to crusher and for storage
place through conveyor.
Junction tower - JTs are used where the conveyor
has any angular deviation.
Primary crusher – The raw coal is crushed into
fine pieces of 45mm grit. Primary crusher is also
called Rotatory breaker since the coal is crushed by
rotating plate.
The stone and
unwanted coal
are rejected

11. Secondary crusher – The fine pieces
of coal is crushed into powder . (25
mm grit).
Junction Tower
Mill Bunker – The 25 mm grit coal is
crushed into very fine powder for
feeding the boiler . We have a spare
bunker for each boiler.
Boiler
Stack & Reclaimer – It is
used to store the powdered
coal for emergency purpose.
Atmospheric air
–Through FD
fan

12. BOILER
 A Boiler is a closed vessel in which water is heated to produce steam by utilizing the
heat generated by coal combustion.
Boilers are classified into two types based on relative position of water and hot gases
:-
 Water tube boilers
 Fire tube boilers
In Water tube boiler, water flows through tubes
and hot gases of combustion flow over these tubes.
This is high pressure boilers.

13. In Fire tube boiler, the hot products of combustion
passes through tubes surrounded by water . This is low pressure boiler.
In Dadri power plant, Water tube boiler is used.
Saturated steam is generated at a pressure of around 2000-2200 KPa.
It is then heated in Superheater.

14. Auxilliary Components Of a Boiler
 Superheater
 Economizer
 Air-preheater
 Reheater
 Deaerator

15. Superheater
 Superheaters are used to raise the steam temperature above the saturation temperature by absorbing
heat from flue gases to increase plant efficiency.
 It removes last traces of moisture and therefore prevents turbine blades from corrosion.
 Outlet temperature and pressure of steam coming out from the superheater is 540 °C & 157 kg/cm²

16. Economiser, Air-preheater & Reheater
 An Economizer is a heat transfer device used for heating
the feed water with the help of hot flue gases.
 It improves the efficiency of the power plant.
 Air-preheater is a device which utilizes the waste heat
of the flue gases leaving the Economizer for heating
the air required for combustion.
 Reheater is used to increase the temperature of exhaust
steam from HP turbine by utilizing the heat of the hot
flue gases leaving the chimney.

17. Deaerator
 A steam generating boiler requires that the boiler feed water should be devoid of air and other
dissolved gases, particularly corrosive ones.
 In order to avoid corrosion of the metal, power
station uses a Deaerator, for the removal of air
and other dissolved gases from the boiler
feed water.
 A Deaerator has a vertical, domed deaeration section
mounted on top of a horizontal cylindrical vessel
which serves as a deaerated boiler feed water storage
tank.

18. PRIME MOVER(TURBINE)
 A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and
converts it into mechanical energy.
 About 86% of all electric generation in the world is by use of steam turbines.
 In a thermal power plant generally 3 turbines are used to increase the efficiency.
 High Pressure Turbine(HPT): The superheated steam is directly fed to this turbine to rotate it.
 Intermediate Pressure Turbine (IPT) : The output from the HPT is reheated in a reheater and used to
rotate IPT.
 Low Pressure Turbine (LPT):The Exhausted steam from the IPT is directly fed to rotate the shaft of LPT.
 All the turbines are connected to a single shaft which is connected to the generator.

21. CONDENSER
 It condenses the steam at the exhaust of the turbine
with the help of cooling water.
 It creates a very low pressure at the exhaust of turbine,
this helps in converting heat energy of the steam into
mechanical energy in the prime mover.
 Condensed steam can be used as feed water to the
boiler.

22. COOLING TOWER
 Removes heat from the water discharged from the
condenser so that the water can be discharged into the
river or recirculated or reused.
 Air can be circulated in the cooling tower through
natural draft and mechanical draft.

24. ELECTROSTATIC PRECIPITATOR (ESP)
Top view Side View
 It is a device which removes dust or other finely divided particles from flue gases by charging the
particles inductively with an electric field, then attracting them to highly charged collector plates.
Also known as precipitator. The process depends on two steps. In the first step the suspension
passes through an electric discharge (corona discharge) area where ionization of the gas occurs. The
ions produced collide with the suspended particles and confer on them an electric charge. The
charged particles drift toward an electrode of opposite sign and are deposited on the electrode where
their electric charge is neutralized.
 It has an efficiency of 99.8 % and it is a very high power consuming device of about 1 kwh for 10
thousand m³ of flue gas.

25. PRIMARY AIR FAN (PAF)
 Air to blow the coal from the mill to the boiler, called the
primary air, is supplied by a large fan driven by a variable
speed motor.
 When mixed with a stream of air the powdered coal
behaves more like a gas than a solid.
 Primary air does two jobs – heating the coal powder and
secondly lifting it into the furnace through pipelines.

26. INDUCED DRAUGHT (ID) FAN
 It is draws out hot flue gases from the boiler.
 The gas has already passed out from Air-
preheater and Electrostatic precipitator before
it reaches ID fan.
 The heat from the flue gases or smoke is used
in the air heaters to heat up the primary and
secondary air.

27. CHIMNEY
 The chimney is 275 meters' high and
50,000 tonnes of reinforced concrete
were used to make it.
 It consists of flues each of which serve
typically two or three boilers.
 It is used to discharge flue gases at high
altitude.

28. ELECTRICAL Equipments
 Alternator
 An alternator is coupled to a steam turbine and converts mechanical energy of turbine into electrical energy.
 It may be Hydrogen or Air cooled.
 The necessary excitation is provided by main and pilot exciters directly coupled to the alternator shaft.
 Transformer
 Main step- transformer : steps up generated voltage transmission of power.
 Station transformer : general purpose
 Auxilliary transformers : which supply to individual unit auxiliaries.
 Control Room and Switch yard
 The control room monitors the overall operation of the plant. It is provided with safety relays and switch gears.

29. ASH HANDLING PLANT
 The percentage of ash in coal is 5% in good
quality coal & about 40% in poor quality coal.
 Power plants generally use poor quality of coal ,
thus amount of ash produced by it is quite large.
 A modern 1000MW plant produces about 4800
tons of ash daily.
 The stations use some conveyor arrangement to
carry ash to dump sites.

30. COAL ASH CAN BE USED IN
 Fly Ash Bricks / Blocks
 Cement Concrete
 Road construction
 Embankment / Back fills / Land development
 Use in agriculture
 Mine filling

31. REFERENCE
 www.ntpc.co.in/index.php?option=com_content&id=312&Itemid.
 en.wikipedia.org/wiki/NTPC_Dadri
 wikimapia.org › India › Uttar Pradesh › Dadri
 articles.economictimes.indiatimes.com › Collections › Solar Plant
 www.ndtv.com › Topic
 www.business-standard.com/.../no-shortage-of-coal-supply-to-ntpc-sdad.
 globalenergyobservatory.org/geoid/4562
 ntpc.co.in/index.php?option=com_content&id=28&Itemid=41

32. THANK YOU