Combined Cycle power plant is a type of plant which consists of two or more power plants but consists of only one supply through inlet. The inlet may pass fuel, water or air as per the requirement and type of plant. Combined Cycle power plant has a thermal overall efficiency of 50 percent and it may increase depending on the type of plant used in the combined operation.
Working of Combined Cycle power plant-
Combined cycle power plant consists of the following parts-
- Gas Turbine
- Steam Turbine
- Gas Turbine
- Inlet of Fuel
- Inlet of Air
- Generator for first cycle
- Generator for second cycle
Detailed steps for the working of Combined Cycle power plant-
- In the Combined Cycle power plant, the first cycle if of thermal or gas plant and the second cycle is of Steam power plant mostly.
- In the first cycle, The Air gets into the compressor with the help of inlet.
- It gets passed to the combustion chamber where the fuel is also supplied.
- The combustion takes place in the combustion chamber and the heat generated is used for the generation of power from the turbine.
- The turbine blades get rotated and the power or energy gets generated.
- The hot gases coming out of the cycle and the part of combustion takes place in the boiler.
- Boiler is a place where the temperature can be raised for liquid or gaseous mixtures.
- The water supplied to the next cycle is from the boiler.
- So the available heat from the boiler is transferred to the water sent from the turbine.
- The water gets heated and gets converted into steam.
- The steam generated in this processes sent to the turbine with the help of a nozzle to increase the velocity of the steam.
- Once the steam is sent to the turbine, the turbine blades gets rotated and energy is produced.
- The steam is sent out to the condenser from which it is sent out or can be further re used.
- In both the power plants, generators are used for the generation of power.
- Generator converts the Mechanical energy into Hydraulic energy.
This is known as Combined Cycle power plant and this is the working.
Advantages of applying Combined Cycle power plant-
- The power generated by both the Combined Cycle power plants is more when compared to single plant.
- The Thermal efficiency and Mechanical efficiency of the Combined Cycle power plant is more, even than Hydro power plant.
- The overall efficiency of this plant is very high when compared to any type of plant.
- The cost of the fuel is very cheap.
- The availability of the fuel is abundant in nature.
- It does not cause pollution to atmosphere as it is further used to reduce the effects in the environment.
- The Combined Cycle power plant is more suitable for quick starting and stopping even in the times of extreme cold and hot temperatures.
- These accept varying loads and can be used as Base load and Peak load plants.
- Low Operational cost.
Disadvantages of Combined Cycle power plants-
- High Maintenance cost of the plant.
- The initial cost of the plant is very high when compared to simple power plants.
- Trouble in the first plant causes the second plant malfunctioning.
- Trouble in the first plant causes the entire plant to be shut down.
These are the advantages and disadvantages of Combined Cycle power plants.