The compressors used in a gas turbine are typically of which type?

Concept:

Compressor:

• The air compressor used in gas turbines is of rotary type mainly axial flow turbines. 
• It draws air from the atmosphere and compressed to the required pressure.

Compressors can be of two types:

1. Positive displacement type Compressor:
   • Positive displacement type like reciprocating compressors, Root's blower, and vane - sealed machines.
2. Rotary type Compressor:
   • Rotary type like centrifugal and axial flow compressor.

• The principal type of compressor used nowadays, in the majority of the gas turbine power plants are especially in aircraft applications, is the axial flow compressor.

Axial flow compressors:

• Axial flow compressors are used in all larger gas turbine units because of their high efficiency and capacity (larger air handling ability) and it is an alternative of the centrifugal compressor due to heavyweight and large cross-sectional area.
• In the axial flow compressor, the inlet and outlet of air are parallel to the rotating shaft axis.

Centrifugal compressors:

• Centrifugal compressors are more stable than axial flow ones but of much low capacity and not as efficient. 

Other Main components for gas turbine:

Combustion chamber: 

• The compressed air from the air compressor is drawn to the combustion chamber. 
• The fuel is injected into the air and then ignited in the combustion chamber. 
• It increased the pressure and temperature of the air instantaneously.

Turbine: 

• The high pressure and temperature air are expanded in the turbine.
• The turbine is also of the rotary type. During the expansion, the heat energy in the gas is converted into mechanical energy. 
• This mechanical energy is again converted into electrical energy by using the generator