| 摘要 |
<p>A refrigerating cycle using carbon dioxide as a refrigerant, wherein, when a high-pressure side refrigerant pressure is near a critical point, the degree of undercooling is set at approx. 15°C and, as it lowers from near the critical point, the degree of undercooling is decreased gradually and, when the refrigerating cycle is provided with a variable displacement compressor, a radiator, an expansion device, an evaporator, and an inside heat exchanger, the operating conditions of the compressor including its delivery amount are adjusted so as to set a refrigerant pressure on the flow-in side of the expansion device at a high level when a refrigerant temperature is the same as that in a refrigerating cycle which has not the inside heat exchanger and a refrigerating cycle which has a fixed compressor delivery capacity and to set the refrigerant temperature at a low level when the refrigerant pressure is the same as that in these cycles, whereby the refrigerating cycle using carbon dioxide as a refrigerant can be operated efficiently.</p> |
