Refrigeration questions

[wrx]

Hi i have a couple of questions i want to ask because im not quite sure on how to work it out. The question is- A four cylinder compressor has a stroke of 12cm, a bore diameter of 10cm and is rotating at 680 rpm. It is delivering R134A to the tx valve at a condensing temp of 34 degrees C and the evaporating temp is -2 degrees C.

I need to know the ratio of compression, the refrigerating effect and the actual refrigerating capacity if it has a volumertic efficiency of 78%.

I would really like to know the formulas to work out these answers to please:)

[NoNickName]

The equivalent pressure of 34°C for R134a is ?
The equivalent pressure of -2°C for R134a is ?
The pressure ratio is the first divided the second.

The flow rate is easily calculated from the compressor displacement times the rotational speed.

From there every other data is easily obtained.

do your homework.

[TXiceman]

Wonder if this is a student trying to get his project work done.....

ken