Refrigeration device

A refrigeration device comprising:

• a high-order side refrigerant circuit through which a high-order side refrigerant circulates and in which a high-order side compressor, a high-order side heat medium heat exchanger, a high-order side pressure reduction mechanism, and a cascade heat exchanger are sequentially connected via refrigerant pipes, the high-order side heat medium heat exchanger being configured to perform heat-exchange between the high-order side refrigerant and a heat medium;
• a low-order side refrigerant circuit through which a low-order side refrigerant circulates and in which a low-order side compressor, the cascade heat exchanger, a low-order side heat medium heat exchanger, a low-order side pressure reduction mechanism, and a low-order side heat exchanger are sequentially connected via refrigerant pipes, the low-order side heat medium heat exchanger being connected in parallel with the cascade heat exchanger and configured to perform heat-exchange between the low-order side refrigerant and the heat medium;
• and
• a control unit configured to control the high-order side refrigerant circuit and the low-order side refrigerant circuit, wherein:
• the control unit switches between a single operation and a dual operation,
• the single operation being an operation in which the heat medium is heated by the low-order side heat medium heat exchanger by circulating the low-order side refrigerant through the low-order side refrigerant circuit without circulating the high-order side refrigerant through the high-order side refrigerant circuit,
• the dual operation being an operation in which the heat medium is heated by the high-order side heat medium heat exchanger by circulating the high-order side refrigerant through the high-order side refrigerant circuit, circulating the low-order side refrigerant through the low-order side refrigerant circuit, and performing heat-exchange between the high-order side refrigerant and the low-order side refrigerant in the cascade heat exchanger;
• the low-order side refrigerant circuit includes a low-order side cutoff unit configured to block the low-order side refrigerant from flowing into the low-order side heat medium heat exchanger;
• and
• the high-order side refrigerant circuit includes a high-order side cutoff unit configured to block the high-order side refrigerant from flowing into the high-order side heat medium heat exchanger.