i'm sorry for bringing old topic to the top, but there are still people with blanks in their knowledge base

Originally posted by Prof Sporlan
And volumetric flow thru the compressor becomes: 0.066 / 14.58 * 3600 = 16.3 m3/hr
So we received a theoretical compressor's volume capacity of 16.3m3/hr.

At first approach, we can use it in getting the compressor's model. But if we'll choose the comperssor with displacement of 16.3m3/hr, and recalculate it's refrigeration capacity at given conditions, we will get lower capacity than we used to calculate volumetric flow.

As far as i know, every compressor has its volumetric efficiency, which has the nature of displacement, but depends also on discharge and suction pressure ratio, mainly, and some other conditions (temperatures, gas velocities, etc) in less manner.

I would like to get help on:

If i know the refrigerant volumetric flow, it's temperatures, it's velocities (at least in suction line), How can i calculate the REAL compressor's volume efficiency? (with accuracy of less than 3-5%)