Quote Originally Posted by Andy P
Coolpack (much mentioned in dispatches recently) gives you a very quick answer - if your first stage suction was at 1 bar abs and 15C then the index of compression is 1.399 Assuming a pressure ratio of 5 then the inlet to the second stage is 5 bar abs and 15C so the second stage index would be 1.404. If the pressure ratio is 5 again then the 3rd stage inlet is 25 bar abs and 15C, so the index of compression is 1.436
Pretty much what I expected. About a 2.5% deviation across the max. range.

In some of the older refrigerant tables these values are listed at one condition as a reference only. So be careful of using those values.

Quote Originally Posted by Peter
I just re-read my old school books about this topice and I have to admit that it has become almost Chinese for me. And I succeeded for my exams for this course.
Same problem for me too Peter. I think this falls into the category of "use it, or loose it".