초록 ▼

A control system for controlling a reversible HVAC system of a motor vehicle is disclosed. The HVAC system includes an electric compressor for circulating a refrigerant through a heat pump. The speed of the compressor is controlled by a compressor control signal having a variable duty cycle. Inside

A control system for controlling a reversible HVAC system of a motor vehicle is disclosed. The HVAC system includes an electric compressor for circulating a refrigerant through a heat pump. The speed of the compressor is controlled by a compressor control signal having a variable duty cycle. Inside and outside heat exchangers transfer heat energy between an outside environment and a passenger compartment of the motor vehicle. A refrigerant flow switching device switches the direction of refrigerant flow towards the inside heat exchanger in a heating mode and towards the outside heat exchanger in a cooling mode. A pressure reducing assembly supplies pressure reduced refrigerant to the inside heat exchanger in the cooling mode and to the outside heat exchanger in the heating mode. The pressure reducing assembly includes an electronic expansion valve in which the flow rate is set by an EXV control signal having a variable duty cycle. A controller controls the duty cycle setting of the compressor control signal and the EXV control signal such that a desired quantity of heat is transferred between the outside environment and the passenger compartment.

대표청구항 ▼

[ What is claimed is:] [1.] A control system for controlling a temperature of a motor vehicle having a passenger compartment, the control system comprising:a heat pump having an electric compressor for circulating a refrigerant in a direction, said electric compressor having a rotating speed related

[ What is claimed is:] [1.] A control system for controlling a temperature of a motor vehicle having a passenger compartment, the control system comprising:a heat pump having an electric compressor for circulating a refrigerant in a direction, said electric compressor having a rotating speed related to a duty cycle of a compressor control signal and a suction pressure related to the rotating speed, first and second heat exchangers for transferring heat energy between an outside environment and the passenger compartment, a refrigerant flow switching device for switching the direction of refrigerant flow towards the first heat exchanger in a heating mode and towards the second heat exchanger in a cooling mode, and a flow management center for supplying pressure reduced refrigerant to the first heat exchanger in the cooling mode and to the second heat exchanger in the heating mode, said flow management center including an electronic expansion valve having a flow rate related to a duty cycle of an EXV control signal;a controller for controlling the duty cycle of the EXV control signal such that efficient operation of the first and second heat exchangers is maintained and for controlling the duty cycle of the compressor control signal such that a desired quantity of heat is transferred between the outside environment and the passenger compartment;a first sensor coupled to the controller to sense a refrigerant parameter reflective of an evaporator refrigerant saturation temperature during the heating mode and the cooling mode; anda second sensor coupled to the controller to sense a refrigerant parameter reflective of an evaporator outlet refrigerant temperature;wherein the controller calculates a refrigerant superheat temperature based on the evaporator refrigerant saturation temperature and the evaporator outlet refrigerant temperature; said controller controls the duty cycle of the EXV control signal such that the refrigerant superheat temperature is maintained substantially at a predetermined superheat temperature, whereby the evaporator is efficiently used for transferring heat energy.