Patent ID: 7178358

Claim:
A vapor-compression refrigerant cycle system comprising: a compressor for sucking and compressing refrigerant; a radiator, provided at a refrigerant discharge side of the compressor, for cooling the refrigerant, the radiator being connected to a refrigerant discharge side of the compressor through a refrigerant circuit; a decompression device for decompressing refrigerant flowing out of the radiator; an evaporator for evaporating the refrigerant after being decompressed in the decompression device, by performing heat exchange with a first fluid; a refrigerant shutting unit disposed in the refrigerant circuit to shut a refrigerant flow from the refrigerant discharge side of the compressor to the radiator; a heater for heating refrigerant, by performing heat exchange with a second fluid different from the first fluid; a refrigerant supply means for supplying refrigerant to the heater while bypassing the refrigerant shutting unit, the refrigerant supplying means supplies refrigerant from a refrigerant outlet side of the radiator to the heater; and an energy recovery unit for expanding the refrigerant flowing out of the heater to recover thermal energy in the refrigerant from the heater, wherein: when a refrigeration cycle where the evaporator has a refrigeration capacity is set, the refrigerant is circulated in this order of the compressor→the radiator→the decompression device→the evaporator→the compressor; when a Rankine cycle where the energy recovery unit recovers the thermal energy is set, the refrigerant shutting unit shuts the refrigerant flow from the refrigerant discharge side of the compressor to the radiator, and the refrigerant is circulated by the refrigerant supply means in this order of the heater→the energy recovery unit→the radiator→the heater; the refrigerant circuit has a first refrigerant path between a refrigerant discharge port of the compressor and the refrigerant shutting unit, and at least a part of the first refrigerant path in the refrigeration cycle is used as a part of a refrigerant suction path for drawing refrigerant to the energy recovery unit in the Rankine cycle; and at least a part of a second refrigerant path between a refrigerant suction port of the compressor and the evaporator in the refrigeration cycle is used as a part of a refrigerant discharge path of the energy recovery unit in the Rankine cycle.