| 摘要 |
The present invention has an object to acquire a refrigeration apparatus that brings the evaporating temperature in a low-temperature-side evaporator into -80 through -60 degrees C, and that has a low GWP and a high reliability. A refrigeration apparatus according to the present invention that performs a two-stage refrigerating cycle, includes a high-temperature-side circulation circuit in which a high-temperature-side compressor, a high-temperature-side condenser, a high-temperature-side expansion valve, and a high-temperature-side evaporator are connected in series, a low-temperature-side circulation circuit in which a low-temperature-side compressor, a low-temperature-side condenser, a low-temperature-side expansion valve, and a low-temperature-side evaporator are connected in series, and through which a refrigerant mixture flows that includes CO 2 and R32 and has the ratio of R32 to the whole refrigerant mixture of 50 to 74%, a cascade condenser that connects the high-temperature-side evaporator and the low-temperature-side condenser in a heat exchangeable manner, and an injection circuit that branches off between the low-temperature-side condenser and the low-temperature-side expansion valve, and is connected to the inside of the low-temperature-side compressor. |
