| 摘要 |
The present invention relates to a heat pump using a cascade cycle, comprising: a low-stage refrigeration cycle in which a first refrigerant circulates along a first circuit comprising a first compressor, a first heat exchanger, a first expansion valve, and a first evaporator; a high-stage refrigeration cycle in which a second refrigerant circulates along a second circuit comprising a second compressor, a second heat exchanger, a second expansion valve, and the first heat exchanger; a bifurcated flow path which is bifurcated between the second expansion valve and the first heat exchanger and is connected between the first heat exchanger and the second compressor; a valve which allows the second refrigerant to pass through the bifurcated flow path or shuts off the second refrigerant; a second evaporator disposed on the bifurcated flow path; and a controller, wherein, when outside temperature is equal to or greater than a predetermined temperature, and heating load is not large, only the high-stage refrigeration cycle is operated, thereby reducing power consumption. |
