| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability by using a refrigerating machine oil exhibiting weak mutual solubility for coolant and, when the ambient temperature of an evaporator is low, reliably returning the refrigerating machine oil to a compressor. SOLUTION: This refrigerating cycle device has an outside air temperature sensor 51 detecting outside temperature and sets a compressor minimum operation frequency on the basis of minimum coolant flow rate that the refrigerating machine oil flowing out of the compressor 1 at starting for every outside temperature is returned to the compressor 1 within a previously set time, and then the device is operated at the minimum operation frequency or higher so as to retain an amount of refrigerating machine oil not causing trouble to operation inside the compressor 1. The minimum opening of a first restriction device 4a is set and the device is operated at the minimum opening or larger. A change in the opening of the restriction device 4a or the restriction start time is controlled. The opening of the restriction device 4a is controlled so as to provide compressor discharging superheat after retaining minimum required amount of the refrigerating machine oil inside the compressor 1. COPYRIGHT: (C)2004,JPO
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