| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater capable of preventing refrigerant gas of an intermediate pressure separated by an intermediate pressure receiver from being sucked into a compression mechanism on a higher stage side of a two-stage compressor in a gas-liquid two-phase condition, and securing the reliability of the two-stage compressor. <P>SOLUTION: The heat pump water heater 1 includes: a refrigerant circulation circuit 2 provided with the two-stage compressor 4, an oil separator 5, a radiator 6, a pressure reducing unit 7, and a heat absorbing unit 11; an oil returning circuit 13 that returns a lubricating oil separated by the oil separator 5 to the refrigerant circulation circuit 2 located on an upstream side of the two-stage compressor 4; and a gas injection circuit 17 that injects the gas refrigerant separated by the intermediate pressure receiver 8 provided on a downstream side of the radiator 6, to the two-stage compressor 4. The heat pump water heater further includes a heat exchanger 20 for exchanging heat between the lubricating oil that passes the oil returning circuit 13 and the refrigerant that pass the gas injection circuit 17. <P>COPYRIGHT: (C)2012,JPO&INPIT |
