Thermal power plant is a non- renewable energy source of electrical power generation. For the generating process or for the raw material the thermal power plant also called Coal thermal power plant and steam turbine power plant.
The working principle of thermal power plant is very simple. The working fluid is water and steam. This is called feed water and steam cycle. The generating process of electricity is rotate like circle chain. At first the coal burns in the furnace and make a enough heat to make steam from the water. Then the steam went to the super heater to make high pressure dry steam. This high pressure dry steam is passed through the turbine. The steam so produced is used in driving the steam Turbines.
This turbine is coupled to synchronous generator, which generates electrical energy. After passing through the turbine blade the steam pressure is decrease. The principle advantages of condensing operation are the increased amount of energy extracted per kg of steam and thereby increasing efficiency and the condensate which is fed into the boiler again reduces the amount of fresh feed water. The condensate gives along with some make up feed water is again fed into the boiler by pump. In condenser the steam is condensed by cooling water. Cooling water recycles through cooling tower. The static pressure inside the steam boiler is maintained by two fans called Forced Draught (FD) fan and Induced Draught (ID) fan.
- 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.
- In turbine this steam force rotates the turbine blades that means here in the turbine the stored potential energy of the high pressured steam is converted into mechanical energy.
- 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.
Site selection of thermal power plant
- The electric power generation plant must be constructed at such a place where the cost of land is quite low.
- A large quantity of cooling water is required for the thermal power generation plant, hence the plant should preferably situated beside big source of natural water source such as big river.
- Availability of huge amount of fuel at reasonable cost is one of the major criterion for choosing plant location.
- The plant should be established on plane land.
- The soil should be such that it should provide good and firm foundation of plant and buildings.
- The thermal power plant location should not be very nearer to dense locality as there are smoke, noise steam, water vapors etc.
- Place for ash handling plant for thermal power station should also be available very near by.
- plant should be located at near to the load station.
Advantages and Disadvantages of Thermal Power Station
- 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 & bulk of water are available.
- 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.
- Overall efficiency of thermal power plant is low like less 30%.