To realize a highly efficient system by recovering heat of oil and utilizing the heat for heating water.
A supercritical heat pump cycle 4 comprises an oil separator 7 for separating a refrigerant and the oil discharged from a compressor 6, and an oil returning passage 12 for returning the oil recovered by the oil separator 7 to the compressor 6 through an oil passage of a water heat exchanger 8. The water heat exchanger 8 comprises a first heat exchanger 8A for exchanging heat between a high temperature high pressure gas refrigerant from which the oil is removed by the oil separator 7 and water to be used for hot water supply or the like, and a second heat exchanger 8B for exchanging heat between the high temperature oil recovered by the oil separator 7 and the water. Directions of refrigerant flow and water flow are opposite to each other. By this constitution, heat of the oil returned from the oil separator 7 to the compressor 6 can be used for heating low temperature water in the water heat exchanger so that the highly efficient system having reduced thermal loss can be realized.
SAKAKIBARA HISASUKE
KOBAYAKAWA TOMOAKI
KUSAKARI KAZUTOSHI
SAIKAWA MICHIYUKI
TOKYO ELECTRIC POWER CO
CENTRAL RES INST ELECT