What are the components of a typical Gas Turbine Power Plant?

A gas turbine power plant is the type of power generating station in which gas turbine is used as the prime mover for the generation of electrical energy.

The schematic diagram of a gas turbine power plant is shown in the figure.

The main components of a typical gas turbine power plant are as follows −

  • Compressor

  • Regenerator

  • Combustion Chamber

  • Gas Turbine

  • Alternator

  • Starting Motor


The compressor is an apparatus used to increase the pressure of air taken from the atmosphere. In gas turbine power plants, rotatory type compressors are generally used.

The air at atmospheric pressure is drawn by the compressor through an air filter which removes the dust from the air. The rotatory blades of the compressor push the air between the stationary blades to increase the pressure. Therefore, the air at high pressure is available at the output of the compressor.


The regenerator is an apparatus which recovers the heat from the exhaust gases of the gas turbine. The regenerator consists of a nest of tubes contained in a shell. The exhaust gases are passed through the regenerator before removing to the atmosphere. The compressed air from the compressor passes through the tubes of the regenerator on its way to the combustion chamber. Therefore, the compressed air is heated by the hot exhaust gases.

Combustion Chamber

The combustion chamber is an apparatus used to increase the temperature of the compressed air. Here, the air at high pressure from the compressor is brought to the combustion chamber through the regenerator.

In the combustion chamber, heat is added to the compressed air by burning of fuel oil. The fuel oil is injected through the burner into the combustion chamber at high pressure to ensure the atomisation of oil and its thorough mixing with the air. Consequently, the combustion chamber attains a very high temperature (about 1700 °C). The gases produced by the combustion are suitably cooled to 700 °C to 800 °C and then delivered to the gas turbine.

Gas Turbine

The gas turbine is a device which converts heat energy of hot gases into mechanical energy. The products of combustion consisting of a mixture of gases at high temperature and pressure are expanded in the gas turbine and does the mechanical work, i.e., it converts the heat energy into mechanical energy.


The gas turbine drives the alternator. The alternator converts the mechanical energy of the turbine into electrical energy.

Starting Motor

Before starting the gas turbine, the compressor has to be started. For this purpose, an electric motor (M) is mounted on the shaft of the turbine. This motor is energised by the batteries. However, once the power plant is started, a part of mechanical power of the turbine drives the compressor and there is no need of the auxiliary motor now.