Hello ~Everybody,,

Can someone please tell me the difference between a one-stage and two-stage refrigeration cycle?

I have come across a diagram here: http://docs.lib.purdue.edu/cgi/viewc...&context=iracc, pg.220 but still can't grasp the basic difference. Is it simply the fact that between the first and second compressors there is a cooling line in the two-stage cycle and not the other? Or does a two-stage cycle even need 'two' compressors at all?

I am quite confused because there are soo many different types of one-stage and two-stage systems, a broader view would be very helpful, Thank you.