Control strategy of a variable displacement compressor operating at super critical pressures

摘要

An air conditioning system for cooling a vehicle passenger compartment is disclosed. The system includes an air duct, a refrigerant circuit, a variable displacement compressor, and a controller. The air duct directs air conditioned air into the vehicle passenger compartment. The refrigerant circuit circulates a refrigerant, wherein a first portion of the circuit is exposed to the air duct and a second portion of the circuit is exposed to air external of the vehicle passenger compartment. The variable displacement compressor is in fluid communication with the refrigerant circuit, wherein the compressor has a control valve for regulating refrigerant flow between a compressor crankcase and a compressor discharge chamber and between the compressor crankcase and a compressor suction chamber. The controller in electrical communication with the variable displacement compressor for controlling refrigerant flow and a displacement of the compressor by actuating the control valves.