Thermal Power Station

1. THERMAL POWER
STATION

2. Thermal power plants are classified by the type of fuel used :
 Nuclear power plants use a nuclear reactor’s heat to operate a steam
turbine generator
 Fossil fuelled power plants may also use a steam turbine generator or
in the case of natural gas fired plants may use a combustion turbine.
 Geothermal power plants use steam extracted from hot underground
rocks
 Renewable energy plants may be fuelled by waste from sugar
cane, municipal solid waste, landfill methane, or other forms of
biomass
 In integrated steel mills, blast furnace exhaust gas is a low-
cost, although low-energy-density, fuel
 Waste heat from industrial processes is occasionally concentrated
enough to use for power generation, usually in a steam boiler and
turbine
 Solar thermal electric plants use sunlight to boil water, which turns the
generator

3. SIMPLE LAYOUT OF AN THERMAL POWER STATION

4. Functional description of Thermal
Power station :
1.COAL FLOW
2.STEAM FLOW
3.WATER FLOW
COMPONENTS DESCRIPTION
1. Coal conveyor
2. Stoker
3. Pulverizer
4. Boiler
5. Coal ash
6. Air preheater
7. Electrostatic precipitator
8. Smoke stack
9. Turbine
10.Condenser
11. High - voltage power lines

5. Basic Operation
• A thermal power plant basically works on Rankine cycle.
Coal conveyor
• This is a belt type of arrangement.
• With this coal is transported from coal storage place in power plant
to the place near by boiler.
Stoker
• The coal which is brought near by boiler has to put in boiler
furnance for combustion.
• This stoker is a mechanical device for feeding coal to a furnace.
Pulverizer
• The coal is put in the boiler after pulverization. For this pulverizer
is used.
• A pulverizer is a device for grinding coal for combustion in a
furnace in a power plant.

6. Coal Based Power Plant:

7. The Functioning of the Plant
 The four circuits of the thermal power plant make a complete picture when put
together helping to generate electricity out of fuels such as coal which is the most
widely used fuel.
 The calorific value of coals depends on the quality of the coal and the place from
where it is mined.
Then the quantity of coal required per hour would be given by
Weight of Coal Required
==> Capacity * Steam Requirement * Heat Delivered/Calorific Value of Coal *
Efficiency of Boiler
==> {1000 * 1000 * 5 * 500}/{5000 * 0.75 * 1000} = 666 tons/hr

8. • When coal is used for electricity generation, it is usually
pulverised and then burned in a furnace with a boiler.
• The furnace heat converts boiler water to steam, which is then
used to spin turbines which turn generators and create
electricity.
• The thermodynamic efficiency of this process has been
improved over time.
• ‘Standard’ steam turbines have topped out with some of the
most advanced reaching about 35% thermodynamic efficiency
for the entire process, which means 65% of the coal energy is
waste heat released into the surrounding environment. Old coal
power plants, especially ‘grandfathered’ plants, are significantly
less efficient and produce higher levels of waste heat.
• About 40% of the world's electricity comes from coal.

9. Working of a Coal for Generating Electricity :

11. Advantages of coal based thermal Power Plant :
 They can respond to rapidly changing loads without difficulty.
 A portion of the steam generated can be used as a process steam in
different industries.
 Steam engines and turbines can work under 25 % of overload
continuously.
 Fuel used is cheaper.
 Cheaper in production cost in comparison with that of diesel power
stations.