Heat pump apparatus

A heat pump apparatus comprising:

• a refrigerant circuit that circulates a non-azeotropic mixture refrigerant including a first refrigerant and a second refrigerant having a boiling point higher than the first refrigerant;
• a compressor provided in the refrigerant circuit to compress the non-azeotropic mixture refrigerant;
• a composition adjustment mechanism provided in the refrigerant circuit to prevent an increase in a rate of the first refrigerant included in the non-azeotropic mixture refrigerant discharged from the compressor, and
• an accumulator that is provided in the refrigerant circuit and includes a first channel connected to a suction port of the compressor and an outlet connected to the first channel, wherein
• the first refrigerant is a compound represented by a molecular formula having one or more carbon-carbon unsaturated bonds, and
• the composition adjustment mechanism prevents an increase in a rate of the first refrigerant entering the suction port of the compressor as compared with a rate of the first refrigerant included in the non-azeotropic mixture refrigerant entering the accumulator.