Patent ID: 7076964

Claim:
A super-critical refrigerant cycle system comprising: a refrigerant compressor for compressing refrigerant to a pressure equal to or higher than critical pressure of the refrigerant; a heating heat exchanger having a first section through which the refrigerant flows and a separate second section through which a fluid other than the refrigerant flows, the heating heat exchanger heating the fluid by performing heat-exchange between the fluid and the refrigerant discharged from the refrigerant compressor; a refrigerant evaporator for evaporating refrigerant; an internal heat exchanger for performing heat-exchange between refrigerant flowing out from the heating heat exchanger and refrigerant flowing toward the refrigerant compressor after leaving the refrigerant evaporator; a decompression valve for decompressing refrigerant coming directly from the internal heat exchanger, and for supplying the decompressed refrigerant to the refrigerant evaporator; and a controller that controls a valve open degree of the decompression valve to control a pressure of high-pressure side refrigerant after leaving the heating heat exchanger and before being decompressed to continuously set a state where a difference between a refrigerant outlet temperature of the first section of the heating heat exchanger and a fluid inlet temperature of the second section of the heating heat exchanger approaches a predetermined temperature value.