摘要 |
A defroster restrains a vane jump that takes place when an evaporator is defrosted in a refrigerant circuit using a so-called internal intermediate-pressure type double-stage compression rotary compressor. The defroster includes a rotary compressor that discharges a refrigerant gas that has been compressed by a first rotary compressing unit into a hermetic vessel and further compresses the discharged intermediate-pressure refrigerant gas, a gas cooler, an expansion valve, and an evaporator. To defrost the evaporator, the refrigerant gas discharged from the second rotary compressing unit is introduced into the evaporator without decompressing it by the expansion valve. Furthermore, the refrigerant gas discharged from the first rotary compressing unit is introduced into the evaporator. At the same time, an electromotive unit of the rotary compressor is run at a predetermined number of revolutions. The inertial force of a vane at the foregoing number of revolutions is set to be smaller than the urging force of a spring.
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