This ppt gives the basic working og thermal power plant and its components.

1. Thermal Power Plant
Vinod Srivastava
B.Tech (EE) MJPRU Bareilly
M.Tech (I&C) NITTTR CHD

3. Theory of Thermal Power Station
 The theory of thermal power station or working of thermal power
station is very simple.
 A power generation plant mainly consists of alternator runs with
help of steam turbine.
 The steam is obtained from high pressure boilers. Generally in India,
bituminous coal, brown coal and peat are used as fuel of boiler.
 The bituminous coal is used as boiler fuel has volatile matter from 8
to 33% and ash content 5 to 16%.
 To increase the thermal efficiency, the coal is used in the boiler in
powder form.

5. Working
 In coal thermal power plant, the steam is produced in high pressure in the steam boiler due to
burning of fuel (pulverized coal) in boiler furnaces.
 This steam is further supper heated in a superheater. This superheated steam then enters into the
turbine and rotates the turbine blades.
 The turbine is mechanically so coupled with alternator that its rotor will rotate with the rotation of
turbine blades.
 After entering in turbine the steam pressure suddenly falls and corresponding volume of the steam
increases.
 After imparting energy to the turbine rotor, the steam passes out of the turbine blades into the
condenser.
 In the condenser, the cold water is circulated with the help of a pump which condenses the low-
pressure wet steam.
 This condensed water is further supplied to a low-pressure water heater where the low-pressure
steam increases the temperature of this feed water; it is again heated in high pressure.

6. Advantages
 Economical for low initial cost other than any
generating plant.
 Land required less than hydro power plant.
 Since coal is main fuel and its cost is quite cheap than
petrol/diesel so generation cost is economical.
 Maintenance is easier.
 Thermal power plant can be installed in any location
where transportation and bulk of water are available.

7. Disadvantages
 The running cost for a thermal power station is
comparatively high due to fuel, maintenance etc.
 Large amount of smoke causes air pollution. The thermal
power station is responsible for Global warming.
 The heated water that comes from thermal power plant has
an adverse effect on the aquatic lives in the water and
disturbs the ecology.
 Overall efficiency of thermal power plant is low like less
30%.

8. Components of Thermal
Power Plant

9. Boiler
 Steam boiler or simply a boiler is basically a closed
vessel into which water is heated until the water is
converted into steam at required pressure.

10. Working Principle of Boiler
 The boiler is essentially a closed vessel inside which
water is stored. Fuel (generally coal) is burnt in a
furnace and hot gasses are produced.
 These hot gasses come in contact with water vessel
where the heat of these hot gases transfer to the water
and consequently steam is produced in the boiler.
 There are mainly two types of boiler – water tube boiler
and fire tube boiler.

11. In fire tube boiler, there are numbers of tubes
through which hot gases are passed and water
surrounds these tubes.
Water tube boiler is reverse of the fire tube
boiler. In water tube boiler the water is heated
inside tubes and hot gasses surround these
tubes.

12. SUPERHEATER
A superheater is a vital part of the a boiler
system that is used to increase the overall
efficiency of a thermal power plant.
More specifically, it is a device which converts
wet steam (saturated steam) into dry steam as
dry steam contains more thermal energy.

13. ECONOMISER
 An economiser is a mechanical device which
is used as a heat exchanger by preheating a
fluid to reduce energy consumption.
 In a steam boiler, it is a heat ex-changer device
that heats up fluids or recovers residual heat
from the combustion product i.e. flue gases in
thermal power plant before being released
through the chimney.
 Flue gases are the combustion exhaust gases
produced at power plants consist of mostly
nitrogen, carbon dioxide, water vapor, soot
carbon monoxide etc.

14. AIR PREHEATERS
 They are heating the air
passing through it by means of
wasted heat energy hence air
preheateras are used in various
areas such as boilers, industrial
furnace units and in hot-air
ventilation systems.
 Design of an Air preheater is
depend on the application.

15. STEAM TURBINE
 In simple terms, a steam turbine works by using a heat source (gas, coal,
nuclear, solar) to heat water to extremely high temperatures until it is
converted into steam.
 As that steam flows past a turbine’s spinning blades, the steam expands and
cools.
 The potential energy of the steam is thus turned into kinetic energy in the
rotating turbine’s blades. Because steam turbines generate rotary motion,
they’re particularly suited for driving electrical generators for electrical
power generation.
 The turbines are connected to a generator with an axle, which in turn
produces energy via a magnetic field that produces an electric current.

17. CONDENSER
Condenser condenses the steam which comes
from the turbine into water at a very low
pressure.
But here the question arises why we need to
condense the steam into water.

18. Reference
Electrical4u
http://electricalarticle.com/components-
working-thermal-power-plants/
https://www.thermodyneboilers.com/compone
nts-working-thermal-power-plant/