Refrigeration cycle apparatus

A refrigeration cycle apparatus comprising:

• an outdoor unit comprising a compressor, a first heat exchanger, and a first expansion valve;
• an indoor unit comprising a second expansion valve and a second heat exchanger;
• and
• a first pipe and a second pipe connected between the outdoor unit and the indoor unit,
• in a cooling operation, refrigerant delivered from the compressor sequentially passing through the first heat exchanger, the first expansion valve, the first pipe, the second expansion valve, the second heat exchanger, and the second pipe and returning to the compressor,
• in the cooling operation, the first expansion valve being configured to convert refrigerant from a liquid-phase state to a two-phase state and send two-phase refrigerant to the first pipe, wherein
• the outdoor unit further comprises
• a third expansion valve arranged between the first heat exchanger and the first expansion valve in a refrigerant circuit, and
• a cooling unit arranged between the first expansion valve and the third expansion valve in the refrigerant circuit, the cooling unit is configured to cool refrigerant that flows through a flow path that connects the first expansion valve and the third expansion valve to each other, and
• further comprising:
• a first temperature sensor configured to sense a temperature of refrigerant that flows through the first heat exchanger;
• a second temperature sensor configured to sense a temperature of refrigerant in a flow path between the first heat exchanger and the third expansion valve;
• a third temperature sensor configured to sense a temperature of refrigerant suctioned into the compressor;
• a fourth temperature sensor configured to sense a temperature of refrigerant that flows through the second heat exchanger;
• and
• a controller configured to control opening of the first to third expansion valves, wherein
• the controller is configured to control opening of the first expansion valve so as to set a difference between a temperature detected by the fourth temperature sensor and a temperature detected by the third temperature sensor to a predetermined value in the cooling operation, and
• the controller is configured to control opening of the third expansion valve so as to set a value obtained based on a ratio between a difference between a temperature detected by the first temperature sensor and a temperature detected by the second temperature sensor and a difference between an outdoor air temperature and the temperature detected by the first temperature sensor to be within a predetermined set range in the cooling operation.