Patent ID: 6138468
Filing Date: 2000-10-31
Classification: F04B,F25B

Abstract:
A variable displacement compressor used in a refrigeration circuit that performs heat exchange at temperatures above and below the critical temperature of refrigerant, the compressor comprising:a suction pressure zone, the pressure of which is the pressure of refrigerant drawn into the compressor from a refrigeration circuit;a discharge pressure zone, the pressure of which is the pressure of refrigerant discharged from the compressor into the refrigeration circuit;a control chamber, the pressure of which is a control pressure;a control valve that controls the difference between the control pressure in the control chamber and the suction pressure in the suction pressure zone thereby controlling the compressor displacement, which represents the flow rate of refrigerant in the refrigeration circuit, wherein the control valve controls at least one of the flow rate of refrigerant supplied from the discharge pressure zone to the control chamber and the flow rate of refrigerant released from the control chamber to the suction pressure zone thereby controlling the difference between the control pressure and the suction pressure;means for obtaining information required for controlling the compressor displacement from outside of the refrigeration circuit;means for setting a target value of flow rate of refrigerant in the refrigeration circuit in accordance with the information; anda controller for controlling the control valve such that the target value is sought.