摘要 |
A refrigerating machine including a two-stage compressor, a high-pressure gas cooler, a first expansion valve, an intermediate-pressure receiver, a second expansion valve, and an evaporator is further equipped with an intermediate-pressure refrigerant bypass circuit for bypassing gas refrigerant in the intermediate-pressure receiver to an intermediate-pressure portion of the two-stage compressor, a back flow preventing device provided to the intermediate-pressure refrigerant bypass circuit for preventing back flow of refrigerant from the two-stage compressor to the intermediate-pressure receiver, and a refrigerant-pressure control unit for controlling the pressure of the refrigerant in the intermediate-pressure receiver on the basis of the difference between a specific enthalpy of refrigerant discharged from the high-pressure gas cooler and a predetermined reference enthalpy.
|