Patent ID: 6449971
Filing Date: 2002-09-17
Classification: B60H,F04B,F25B

Abstract:
An air-conditioning system comprising a variable displacement type compressor for compressing and discharging a refrigerant on the one hand and changing the discharge capacity by changing the control pressure on the other hand, and a cooling circuit and a heating circuit sharing the use of said variable displacement type compressor, one of said cooling circuit and said heating circuit being selectively used,said system further comprising capacity control means for controlling the discharge capacity of said variable displacement type compressor based on selected one of the differential pressure between the pressure in the discharge pressure area and the pressure in the suction pressure area and the differential pressure between the pressure in said discharge pressure area and said control pressure, wherein said discharge capacity is both controlled by said capacity control means regardless of whether the refrigerant is circulated in said cooling circuit or in said heating circuit, and wherein said capacity control means controls said discharge capacity downward in the case where said differential pressure exceeds a preset differential pressure level.