3. Thermal power plant converts 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 source of energy.
4. A generating station which converts heat energy of coal
combustion into electrical energy is known as thermal
6. Coal handling plants
Ash handling plant
Cooling towers and ponds
Feed water heater
Super heater and re-heater
7. The function of coal handling plant is automatic feeding of coal
to boiler furnace.
A thermal power plant burns enormous amounts of coal.
A 200 MW plant may require around 2000 tons of coal daily.
8. Pulverizing is a means of exposing a
large surface area to the action of
oxygen and consequently helping
Ground to dust like size and carried to
the furnace in a stream of hot air.
9. • The circulation of air is caused by difference in Pressure known as DRAFT.
• Draft is a differential pressure b/w atmosphere and inside the boiler.
• It is necessary to cause the flow of gasses through boiler setting it may be –
1. Natural draft
2. Mechanical draft
10. A boiler is closed vessel in
which water under pressure, is
converted into steam.
It is one of the major
component of a thermal power
plant. Always designed to
absorb maximum amount of
heat released in the process of
boilers are two type-
1. Fire tube boiler
2. Water tube boiler
11. 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 very large.
A modern 2000MW plant produces about 5000 tons of ash daily.
The station use some conveyor arrangement to carry ash to dump sites directly or
for carrying and loading it to trucks and waggons which transport it to the site of
12. A steam turbine heat energy of steam into mechanical energy and drives
It is use the principal that steam when issuing from a small opening attains
a high velocity.
There are two types of turbine-
1. Impulse turbine
2. Reaction turbine
13. Alternator convert mechanical energy of turbine into electrical energy.
Turbine and alternator are mechanical coupled with each other
The electrical output from the alternator is delivered to the bus bar through
14. Steam after rotating steam turbine comes to condenser refers here to the shell and
tube heat exchanger installed at outlet of every steam turbine in thermal power
station of utility companies generally.
These condenser are heat exchanger which converts steam from it gaseous to its
liquid state, also known as phase transition.
15. A condenser needs huge quantity of
water to condense the steam.
Most plant use a closed cooling
system warm water coming from
condenser is cooled and reused.
Cooling tower is a steal or concrete
hyperbolic structure having a
reservoir at the base.
16. 1. Fuel cost of thermal power plant is relatively low.
2. We can produce thermal energy almost every where in the
3. Heat production System is simple compared to other
4. Overall system cost effective.
5. Easy mechanism.
6. Same heat could be reused.
7. Easier Maintenance of power station.
8. Thermal power plant requires comparatively small space
to be installed.
17. 1. Huge production of Carbon-di-oxide (CO2) in the atmosphere.
2. Exhausted gases harms outside environment badly.
3. Low overall efficiency.
4. Thermal engines requires huge amount of lubricating oil that
is very expensive.
5. Nuclear thermal power plant demands excessive amount of
water for cooling purpose.
6. Coal type thermal power plant requires comparatively larger
duration before it supply generated power to the grid.
7. This type of power station ultimately responsible for raise in
sea water level.
18. Thermal power plants are goods that produce electricity.
As demand for electrical power increases throughout
the world, various plants intends to continue to strive to
supply power plants that provide reliability, high
performance and low price in accordance with the need