Compessed air volume and compressor efficiency. 1

[Johners]

I'm trying to get info together for our compressor set up. What I need is to get some idea of how compressed air volume and compressor efficiency are affected by inlet air temperature variations. The aim is to see if there is justification in supplying the compressor inlet externally from compressor room rather than internally.

If any one has some ideas or just rules of thumb it would be helpful.

 

[dcasto]

Theoretically, the effiency of the compression cycle should not change due to inlet temperature. What will change is the SCFM. The ACFM will be constant, but the higher temperature will reduce the SCFM by (COLDTemp+460)/(HOTTemp +460).

Because the overall effiency in the compressor is also related to pressure losses in piping, valves, and passages, the effiency will drop with higher suction temperatures. The exact amount is a function of mechanical design and not thermodynamics. I ran a check on an Ariel compressor and saw a 5% increase in HP/MCSF when the suction temperature was raise from 100 F to 150 F.

 

[israelkk]

dcasto

I think that it sould be SQRT((COLDTemp+460)/(HOTTemp +460).)

 

[dcasto]

no, its directly proportional as in PV= znRT and
P1 / T1 = P2 / T2 Its adjusting the volume, not the flow rate.