Farzad Jafarkazemi - Islamic Azad Univeristy, South Tehran Branch
Mahdi Golkhani - Islamic Azad Univeristy, South Tehran Branch

It is the aim of this paper to have a review on possible two stage refrigeration systems and investigate the correctness of some traditional rule of thumb calculations in these systems. Further to a review of the basics of two stage refrigeration methods, different alternatives are compared. Effect of inter-stage pressure and volume ratio are calculated and their effects on system performance are evaluated. The calculation results of the paper shows that the optimum displacement ratio increases with increasing the temperature lift.

refrigeration, two stage, volume ratio