BY- RANJAN KUMAR

1. SUMMER PRACTICAL TRAINING
AT
SUBMITTED BY:-
RANJAN KUMAR
14EAIEE079
B.Tech. IV Yr. VII SEM
SUBMITTED TO :-
Mr. Deepak Sharma
Head of Department
Electrical Engineering
NATIONAL THERMAL POWER CORPORATION LTD. ( NTPC )
KAHALGAON (BIHAR)

2. CONTENTS :-
1. Introduction
2. Coal Handling System
3. Ash Handling System
4. Boiler and its auxiliaries
5. Turbine and its auxiliaries
6. Off-Site Department
7. Electric Generator and its auxiliaries
8. Electric Transformer
9. Switchyard
10.Control and Instrumentation Department
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3. 1. Introduction about NTPC :-
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NTPC Limited is the largest thermal power generating company of India.
Established in 7 November 1975.
In 1997, Government of India granted NTPC status of “Navratna” company.
NTPC became a “Maharatna”company in May, 2010, one of the only four
companies to be awarded this status in India.
 Present installed Capacity of NTPC is 51,635 MW .
Total 48 NTPC in India.
 It has 20 coal based power stations (38,755 MW) .
7 gas based power stations (4,017 MW)
9 Joint Ventures based power stations (7,216 MW).
11 renewable energy based power plant(845 MW)
Annual turnover of Rs. 73,904 cr. with profit of Rs. 13,834 Cr. for the year 2013-14.
It contributes 28.60% of total power .

4. National Thermal Power Corporation LTD. (NTPC)
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5. Introduction about NTPC Kahalgaon Bihar :-
Location : Kahalgaon , District-Bhagalpur (Bihar) , 813214
Total Land : 3,360 acres
Land for plant : 883 acres
Land for township : 432 acres
Land for Ash dyke :1395 acres
Source of water : Ganga River
Source of coal : Rajmahal coal field of ECL (Lalmatia , Jharkhand)
 Configuration: stage -1 has 4 unit (each unit capacity 210 MW) , which
was established by Russia in 1991.
stage -2 has 3 unit (each unit capacity 500 MW) , which
was established by BHEL in 1996.
Total installed capacity : 2340 MW
Fuel Requirement : 4.1 million ton per year stage -1
: 6.62 million ton per year for stage -2 ( phase-1 )
: 3 million ton per year for stage -2 ( phase-2 )
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6. 5

7. 2. Coal Handling System Equipment :
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Wagon
 Tripler
Conveyor Belt
Pulleys
Magnetic separator
Crushing house
Vibrating screen
Pulverized coal
Storage of coal
The function of coal handling plant is automatic feeding of coal to the boiler
 A thermal power plant burns enormous amounts of coal.
 In NTPC Kahalgaon 2340MW Plant may require around 23400 tons of coal daily.
Step in coal handling plant:

8. 7

9. Why Coal?
Coal
55%
Gas
10%
Diesel
1%
Hydel
26%
RES
5%
Nuclear
3%
Share of Coal in Power Generation
Advantages of Coal Fuel
•Abundantly available in India
•Low cost
•Technology for Power Generation well
developed.
•Easy to handle, transport, store and use
•India’s Coal Reserves are estimated to be 206 billion tones. Present consumption is
about 450 million tones.
•Cost of coal for producing 1 unit of electricity is Rs 0.75.
•Cost of Gas for producing 1 unit of electricity is Rs 1.20. 8

10. 3. Ash Handling System:
 WHAT IS ASH ?
Ash is the collection of residuals producing after the combustion of coal at
constant weight under standard conditions.
Ash is oxidized form of the mineral matters present in coal.
Typical ash composition : SiO2, Al2O3, Fe2O3, CaO, MgO etc.
 WHY ASH HANDLING?
 Ash content of Indian coal used in power station is about 30 to 40 %.
 A typical 2000 MW station produce around 9000T to 12000T of ash per day.
 This huge amount of ash needs to be disposed off continuously.
 Necessary care to be taken for preventing pollution. 9

11.  Bottom ash can be collected at furnace bottom as Wet or Dry form.
 Bottom ash is the heavier portion of coal ash that settles on the ground in the boiler.
 Bottom ash is part of the non-combustible residue of combustion in a furnace or
incinerator.
 Approximately 80% of bottom ash consist overall of coal ash content.
1. Bottom Ash:
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12. 2. Fly Ash:
• Fly ash, also known as “pulverized fuel ash”.
• Ash generated in the ESP which got carried out with the flue gas is
generally known as fly ash.
• It consist of air preheater ash and economizer ash.
• Approximately 20% of fly ash consist overall of coal ash content.
• FA is collected from Air heater hopper, Eco hopper and ESP hopper.
Use of ash:
• In concrete production
• In cement production
• In stabilization of soft soils
• In bricks production
• Road construction
• Other applications include cosmetics, toothpaste, ceiling tiles, bowling balls,
flotation devices, PVC pipe, picture frames, doors, window frames, park benches
railroad ties.
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13. Coal Seam
Surge Pile
Pulverize (-150)
Overburden
Fly Ash
Flue Gas
Electrostatic Precipitator
Flue Gas
Boiler
Fly Ash Bottom
Ash
Smoke
Stack
Fly Ash
Bottom Ash
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14. Boiler:-
 Boiler is a long column where coal is fired to produce heat and to convert water into superheated steam.
 In NTPC – Kahalgaon, the height of the boiler is 90 meter.
 Type of boiler used in NTPC SSTPS in Stage-I and II are Water tube boilers.
 Maximum Temperature and pressure of main steam for stage -1 is 540ºc and 140 bar respectively.
 Maximum Temperature and pressure of main steam for stage -2 is 545ºc and 170 bar respectively.
 MAIN PART OF BOILER:
1. Economizer 4. super-heater
2. Deaerator 5. Re-heater
3. Furnace 6. Different type of fan
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15. 14

16. A steam turbine is a rotating device which converts thermal energy into mechanical energy.
In NTPC Kahalgaon LMZ (Russia) type steam turbine is used.
There are 3 types of Turbines used in Thermal Power Plants:
1. High pressure turbine (HP Turbine)
2. Intermediate pressure turbine (IP Turbine)
3. Low pressure turbine (LP Turbine)
 Turbine blade is air foil shape.
TURBINE :-
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17. 1. High Pressure Turbine:
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1.HIGH PRESSURE TURBINE:-
 Single Flow Cylinder
 Double Casing
 Thermal expansion up to 16mm

18. 2. Intermediate Pressure Turbine
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2.INTERMEDIATE PRESSURE TURBINE:-
 Double Flow
 Double Casing
 Axially Split Design in both Casings
 Rigid Coupling
 Blade Shrouded & Inverted T-Root
Design

19. 3. Low Pressure Turbine:
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3.LOW PRESSURE TURBINE:-
 Largest Turbine
 Pressure is Very Less
 Three Shell Design
 Double Flow
 All Casings Axially Split
 Exhaust Hood Spray Arrangement
 2 Free Standing Blades in the end

20. 19

21. 1. Water Treatment Plant/DM plant:
Why water treatment?
 Raw water contains many dissolved minerals and organic materials.
 For removal of total solids such as Ca , Mg ,Na ,Cl , Alkalinity , silica etc.
 At high temperature certain minerals left scaling on the tube metal of the boiler and cause permanent damage.
 Some dissolved minerals leads to corrosion of tube metals.
 At high pressure and temperature an element, silica can be carried away with steam causing damage to turbine
low pressure stage.
 The performance and life expectancy of the station greatly depends on water chemistry compliance.
6. Off-Site Department:
1. Water Treatment (DM Plant)
2. Cooling Tower
 Steps of treatment process:
1. Aeration of raw water
2. Adding chemicals for bacteria removal
3. Adding chemicals for sedimentation of suspended particles
4. Flocculation
5. Filtration
6. Ion Exchange process
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22. 2. Cooling Tower:
A cooling tower is a heat rejection device that rejects waste heat to the atmosphere through
the cooling of a water stream to a lower temperature.
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23. 7. Electric Generator and its auxiliaries:
 A turbo generator is the combination of a turbine directly connected to an electric generator
for the generation of electric power.
 An electric generator is a device that converts mechanical energy to electrical energy.
 It is based upon the principle of electromagnetic induction.
 Turbogenerator:
Cooling of Generator :
 Hydrogen cooling: - Rotor core and Rotor winding.
 DM Water cooling:- Stator core and Stator winding.
 Excitation System:
 Maintain the reactive power.
 Wear and Tear problem will be minimize.
 In NTPC Kahalgaon brushless excitation is used. 22

24. Capacity 210 KW
Power Factor 0.85 lagging
KVA 588,000
Stator Voltage 15.75 KV
Stator current 9.03 KA
Rotor Voltage 303 V
Rotor current 2.330 KA
RPM 3000
Frequency 50 HZ
Phase 3
Connection YY
Coolant Water & Hydrogen
Gas Pressure 4 Bar
Insulation Class B
Type TG-HH-0500-2
Make Russia
Stage-1 Turbogenerator Rating:-
Capacity 500 KW
Power Factor 0.85 lagging
KVA 588,000
Stator Voltage 21 KV
Stator current 16.2 KA
Rotor Voltage 340 V
Rotor current 4040 A
RPM 3000
Frequency 50 HZ
Phase 3
Connection YY
Coolant Water & Hydrogen
Gas Pressure 4 Bar
Insulation Class B
Type TG-HH-0500-2
Make BHEL Haridwar
Stage-2 Turbogenerator Rating:-
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25. 8. Electric Transformer:
 A transformer is a device that transfer electrical energy from one electrical circuit to another circuit through the
medium Of magnetic field without change in frequency.
WORKING PRINCIPLE:
Definition:
 It works on FARADAY’S LAW OF
ELECTROMAGNETIC INDUCTION
(self or mutual induction depending on the type of
transformer).
Transformer used in NTPC Kahalgaon:
1. Generator transformer
2. Station transformer
3. Unit Auxiliary transformer (UAT)
4. Other Electric transformer
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26. 9. Switchyard:
 ELECTRICAL EQUIPMENTS:
1. Bus-Bar
2. Lightning Arrester
3. Wave Trap
4. Capacitive Voltage Transformer
5. Relay
6. Circuit Breaker
7. Instrument Transformer
8. Earthing Rod
9. PLCC
10. INSULATORS
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27.  Distribution System:
Figure: Single Line Diagram of NTPC Kahalgaon 400/132 KV Switchyard
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28. 10. Control and Instrumentation Department:
 The main functions of the C&I dept. at
NTPC Kahalgaon are:
1. Measurement and display of various parameters.
2. To control the various parameters by Automatic
feedback controlling which involves the taking of
decision based on inputs from measurements by the
processor.
3. Protection of various equipment’s (pumps, generators
etc.) and workers from hazards by automatically tripping
a cycle when hazardous conditions are reached.
4. Alarm generation in case of a mechanical or an
electrical failure. 27

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