# How to calculate the efficiency of the centrifugal compressor?

## Question:

How to calculate the efficiency of the centrifugal compressor?

## Centrifugal Compressors:

Compressors are one of the important types of rotary compressors and used to raise the pressure of the working fluid such as air, oxygen, nitrogen and so on. The pressure of the fluid raises by the centrifugal force of the impeller.

The efficiency of the centrifugal compressors is ratio of the ideal change in enthalpy to the actual change in enthalpy. Mathematically, this can be written as

{eq}\eta_{comp}=\dfrac {\Delta h_{ideal}}{\Delta h_{actual}}\\ =\dfrac {h_{2'}-h_1}{ h_2- h_1}\\ {/eq}

Where, {eq}h_1 {/eq} is the enthalpy at the inlet of the compressor corresponding to the inlet pressure and inlet temperature.

{eq}h_2 {/eq} is the enthalpy at the exit of the compressor corresponding to the exit pressure and exit temperature.

{eq}h_{2'} {/eq} is the enthalpy at the corresponding to the entropy {eq}s_1=s_{2'} {/eq}. 