2 replies to this topic

[GunaJo]

I'm to trying to calculate the Polytropic work of a centrifugal compressor.Thank you.

Compressor Specifications

Air intake: 7000 m3/hr ( 4120 cfm)
Inlet Temperature: 32 Degree Celsius
Outlet Temperature: = 40 Degree Celsius
Inlet Pressure: 98 Kpa(0.98 bar)(14psi)
Outlet Pressure: 1.1 Mpa(11 bar)(159psi)
shaft power: 790 kw
Motor power: = 895.2 KW
No of stages: 3

[ankur2061]

Gunajo,

You probably want to calculate the polytropic head for your compressor. However, the data does not consist of the properties of the gas to be compressed which includes:

a) Molecular weight of gas

Inlet/Outlet/Avg compressibility factor

c) Specific heat ratio (k =Cp/CV)

I seriously hope you are not expecting somebody to do your homework problem for you. You are advised to look at Perry's Handbook and/or Applied Process Design for Chemical and Petrochemical Plants by Ernest Ludwig, Vol.3 for the relevant equations for calculating the polytropic head of centrifugal compressor.

All the answers are available from the above mentioned books. The initial effort has to come from you. While doing your own calculations, if you hit a snag, we will always help you. Let us see an excel sheet from you with the calculations for starters.

Regards,
Ankur.

[GunaJo]

Hi Ankur,

Thank You for the reply, I will try out what you told me and let you know the result as soon as possible.

From,

Jonathan