Refrigeration cycle apparatus

A refrigeration cycle apparatus comprising:

• a refrigerant circuit including a compressor, a condenser, an expansion device, and an evaporator;
• a first detector provided to the compressor, and configured to detect a temperature of the compressor;
• a second detector provided between the compressor and the expansion device in the refrigerant circuit, and configured to detect one of a temperature of refrigerant and a pressure of the refrigerant;
• an oil separator connected to a refrigerant discharge side of the compressor, and configured to separate a refrigerating machine oil from the refrigerant;
• an oil return pipe connecting the oil separator and a refrigerant suction side of the compressor, and configured to return the refrigerating machine oil stored in the oil separator;
• an oil regulating valve provided in the oil return pipe, and configured to open and close a flow path of the oil return pipe;
• an oil separation switching valve connected to the refrigerant discharge side of the compressor and the oil separator, and configured to switch to connect the compressor and the condenser via the oil separator and to connect compressor and the condenser not via the oil separator;
• and
• a controller configured to control at least one of frequency of the compressor, an opening degree of the expansion device, and an opening degree of the oil regulating valve, and connection of the oil separation switching valve, based on the temperature detected by the first detector and one of the temperature and the pressure detected by the second detector so as to maintain a concentration of the refrigerating machine oil dissolved in the refrigerant in the compressor and an oil level of the refrigerating machine oil in the compressor within respective predetermined ranges.