To prevent a compressor from being damaged by excessive compression in starting.
A bypass valve 81 is opened from the stop of compressors 10a, 10b to the lapse of specified time, and a refrigeration circuit at the side of a condenser 20 is pressure-equalized to that at the side of an evaporator 30. After the bypass valve 81 is closed, a three-way valve 90 is opened, thus opening at least one of the refrigeration circuit 91 connected to the compressor 10a and the refrigeration circuit 92 connected to the compressor 10b, and allowing the refrigeration circuit at the side of the condenser 20 to communicate with that at the side of the evaporator 30 via the compressor 10. As a result, a uniformly pressurized state can be retained, thus preventing much refrigerating machine oil from staying at the suction side of the compressor 10 while the compressor 10 is stopping and preventing the compressor 10 from being damaged by excessive compression in starting.
TAKEUCHI HIROTSUGU
MATSUNAGA HISATSUGU
IKEMOTO TORU
Takahiro Miura
Fumihiro Mizuno
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