| 摘要 |
PROBLEM TO BE SOLVED: To suppress foaming of a heating medium included in a lubricating oil and to prevent damage of a compressor when stopping the compressor.SOLUTION: A heat pump unit 200 includes: a circulation path 210 where a heating medium circulates; a compressor 230; a condenser 240; an expansion valve 260; an evaporator 220; and a control unit 280 for controlling a driving amount of the compressor and opening of the expansion valve, and controlling a circulation amount of the heating medium in the circulation path. When receiving an instruction to the effect that a compression operation of the heating medium by the compressor is stopped, the control unit reduces the opening of the expansion valve so that height of a liquid level of a lubricating oil accommodated in accommodation space does not become below a threshold value preset in the compressor, blocks the inflow of the heating medium into the compressor through the expansion valve by totally closing the expansion valve, and then, stops the compression operation of the heating medium by the compressor. |
