Hysys: Actual gas Flow

[TomX]

Hi,
I wonder if anybody knows what condition represent the Actual gas flow in Hysys.
Is it the actual operational condition (temperature and pressure), or is at 14.4 psia and actual temperature which is the usual "Actual" condition for reciprocating compresors?

Thanks,

 

[invalauble]

I'm pretty sure Actual in HYSYS means actual, at the flowing temperature and pressure (CFM or ACFM). If you wanted that same gas flow rate at Standard conditions, 60 F and 14.7 psia, then you want Standard gas flow rate (SCFM). You could build a table and have it display both Actual and Standard flows, and then just do a hand calculation to check. I don't know what you would mean by saying that when dealing with recip compressors Actual is at 14 psi.

 

[tickle]

The Hysys help desk is very useful and will be able to provide you with a definitive answer to your question.

You could do a quick check your self, by increasing the pressure and seeing if the actual flowrate decreases.

I am in agreement with Invaluable in that I think that the actual recip flowrate is meaningless. Please can you explain the rationale.

 

[TomX]

I have one Hysys simulation done by somebody else, and they keep the actual gas flow constant, when they change operational conditions.

I think the only constant is the piston displacement, but actual gas flow capacity is function of the operational conditions. The pressure 14.4 used as reference for the actual volume flow I founded in several books (GPSA, Gas Engineers Hnadbookk, etc) and that was the reason of the question.
Anyway the answer was easy, just changing the pressure and checking the actual gas flow reported.

Thanks anyway...