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
1. Introduction
2. Power plant layout
3. Coal to Electricity Basics
4. Main and Auxiliary Equipments .
5. Combustion Process
6. Power Plant Cycle
7. Boilers.
8. 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
ASH Loss
Heat
Loss
Elet. Energy
Loss

7. Main and Auxiliary equipments
1. Coal handling plant
2. Pulverizing plant
3. Draft fans
4. Boiler
5. Ash handling plant
6. Turbine
7. Condenser
8. Cooling towers and ponds
9. Economiser
10. Superheater and Reheater
11. 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-
1. Fire tube boiler
2. 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.
SLEEVE
SOLE PLATE
(BASE PLATE)
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
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.
Water Cooled Condenser Air Cooled Condenser

17. HPH 5
PSH
E
C
O
HPH6
LTSH FSH
DRUM
F
U
R
N
A
C
E
HPT IPT LPT
R/H
LPH 1
COND
GSC
CONDENSATE CYCLE
DEA LPH3 LPH2 D/C

18. Cooling towers and ponds
o A condenser needs huge quantity of water to condense the steam .
o Typically a 2000MW plant needs about 1500MGallon of water.
o Most plants use a closed cooling system where warm water coming from condenser is cooled
and reused
o Small plants use spray ponds and medium and large plants use cooling towers.
o Cooling tower is a steel or concrete hyperbolic structure having a reservoir at the base for
storage of cooled water
o 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
Sensible heat Addition in
Economizer
Constant Pressure Heat
Rejection in Condenser
Pump Work
ENTROPY
T
E
M
P
E
R
A
T
U
R
E
Latent Heat Addition in
Evaporator (constt. Pressure) Super Heating
L + V

22. Boiler

24. 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

25. 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.

26. THANK YOU