Centrifugal compressor Control

[rajeshpriyan]

FHi everyone,

I have a 6 stage centrifugal compressure which compress atm air to 19 barg.
Controller provided is of protronic type.
Why does the centrifugal compressor discharge pressure is controlled through the inlet guide vanes(inlet flow).. Why not the pressure can be controlled in discharge?..

Please clarify..

 

[anandm104]

Inlet Guide Vane Regulate the mass flow through compressor. IGV changes the pressure as first stage impeller sees. By throttling IGV, pressure drop is increased causing density to drop and reduction in mass flow is achieved. IGVs are required to improve over all efficiency of compressor when compressor is required to run in throttled condition. When compressor has to be run with full load most of time, IGV is not necessary.