Abstract:In this study, cases of single-stage and multi-stage compression have been compared and contrasted through various angles while concentrating on refrigeration systems with 600 kW cooling capacity and working with ammonia. For five different numbers of stages, power consumption, costs of investment, operation and maintenance (O and M), COP and 2nd law efficiencies have been calculated. As the amount of stages increase, power consumption decreases. The payback period of the gain from this decrease has been calculated as far as the increasing investment expenditures are concerned. Dimensionless profit factor has been calculated according to each case and presented in the diagram.