Heat pump

Abstract

An exemplary heat pump includes: an accumulator that separates liquid refrigerant from gas refrigerant returning to a compressor; a refrigerant suction channel connecting the compressor to the accumulator; a refrigerant return channel that returns liquid refrigerant in the accumulator to the refrigerant suction channel; a first valve disposed on the refrigerant return channel; a temperature sensor that detects a temperature of refrigerant in the refrigerant suction channel; a second valve that reduces a pressure of a part of liquid refrigerant flowing between the first and second heat exchangers; a refrigerant evaporator that gasifies, by using waste heat of an engine, the liquid refrigerant whose pressure has been reduced; a gas refrigerant supply channel through which the gasified refrigerant is supplied to the accumulator; and a control device that, while the first valve is open, controls an opening of the second valve based on the temperature detected by the temperature sensor.