2 Thermal Power Station

 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. 

To increase the thermal efficiency, the coal is used in the boiler in powder form.

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 super heater. 

This supper heated 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 pump which condenses the low pressure wet steam. 

This condensed water is further supplied to low pressure water heater where the low pressure steam increases the temperature of this feed water, it is again heated in high pressure.

For better understanding we furnish every step of function of a thermal power station as follows, First the pulverized coal is burnt into the furnace of steam boiler. 

High pressure steam is produced in the boiler.

This steam is then passed through the super heater, where it further heated up.

This supper heated steam is then entered into a turbine at high speed.

After rotating the turbine blades, the steam has lost its high pressure, passes out of turbine blades and enters into a condenser. 

In the condenser the cold water is circulated with help of pump which condenses the low pressure wet steam. 

This condensed water is then further supplied to low pressure water heater.

Where the low pressure steam increases the temperature of this feed water.

It is then again heated in a high pressure heater where the high pressure of steam is used for heating. 

The turbine in thermal power station

acts as a prime mover of the alternator. 

 Advantages

✓ Economical for low initial cost other than any generating plant.

✓ Land required less than hydro power plant.

✓Since coal is main fuel & its cost is quite cheap than petrol/diesel so generation cost is economical.

✓ There are easier maintenance.

✓ Thermal power plant can be installed in any location where transportation & bulk of water are available.

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 lives in the water and disturbs the ecology.

✓Overall efficiency of thermal power plant is low like less 30%.