A two-stage pressure buildup refrigeration cycle apparatus comprising:
- a low-pressure side compressor that compresses a low-pressure refrigerant to be an intermediate-pressure refrigerant and discharges the low-pressure refrigerant;
- a high-pressure side compressor that compresses the intermediate-pressure refrigerant discharged from the low-pressure side compressor to be a high-pressure refrigerant and discharges the high-pressure refrigerant;
- a condenser that performs a heat exchange between the high-pressure refrigerant discharged from the high-pressure side compressor and outside air, and induces the high-pressure refrigerant to radiate heat;
- a main expansion valve that decompresses and expands the high-pressure refrigerant, which flows out of the condenser after radiating heat, to be the low-pressure refrigerant;
- an auxiliary expansion valve that decompresses the high-pressure refrigerant, which flows out of the condenser after radiating heat, and guides the refrigerant to a suction side of the high-pressure side compressor;
- an evaporator that performs a heat exchange between the low-pressure refrigerant decompressed in the main expansion valve and blown air to be blown into an interior as a cooling target space, evaporates the low-pressure refrigerant, and guides the low-pressure refrigerant to flow to a suction side of the low-pressure side compressor;
- a condenser fan that blows the outside air toward the condenser;
- an evaporator fan that blows air for cooling the interior toward the evaporator;
- and
- a controller that controls the low-pressure side compressor, the high-pressure side compressor, the condenser fan, and the auxiliary expansion valve, wherein
- the controller
- controls, for improving a COP, the low-pressure side compressor and the high-pressure side compressor in a COP improving operation mode in which a refrigerant discharge capacity of one of the low-pressure side compressor and the high-pressure side compressor is set based on a refrigerant discharge capacity of another of the low-pressure side compressor and the high-pressure side compressor, when a required level of a refrigeration performance is low, and
- controls the low-pressure side compressor and the high-pressure side compressor in a high performance operation mode in which a refrigerant discharge capacity of the high-pressure side compressor is increased after increasing a refrigerant discharge capacity of the low-pressure side compressor, when the required level of the refrigeration performance is high, and
- the controller
- increases the refrigerant discharge capacity of the low-pressure side compressor after dissolving a restriction condition that restricts an increase of the refrigerant discharge capacity of the low-pressure side compressor, when the restriction condition is met in the high performance operation mode, and
- increases the refrigeration discharge capacity of the high-pressure side compressor after dissolving a restriction condition that restricts an increase of the refrigerant discharge capacity of the high-pressure side compressor, when the restriction condition is met in the high performance operation mode.