An electric valve and a thermal management system. The electric valve comprises a pressure sensing unit. The pressure sensing unit is connected to a valve seat, and the pressure sensing unit can sense the pressure characteristics of a working medium in a detection flow channel) and form a piezoelectric signal. An electric control portion comprises an electric control board. The piezoelectric signal forms, by means of a conditioning circuit, an electrical signal corresponding to a pressure. The electrical signal is used as a part for generating a signal for controlling a driving portion.

A vehicle air-conditioning device is provided which is capable of eliminating or suppressing vibration and noise generated due to the application of a counterpressure to an opening/closing valve. The vehicle air-conditioning device includes a refrigerant circuit R having a compressor 2, a radiator 4 to perform heat exchange between a refrigerant and air, an outdoor heat exchanger 7, a heat absorber 9, and a solenoid valve 40. The compressor 2 and the solenoid valve 40 are controlled to air-condition a vehicle interior. A decompression speed at a refrigerant inflow side of the solenoid valve when the compressor 2 is stopped and the solenoid valve 40 is closed is faster than that at a refrigerant outflow side thereof. When operation is stopped from a state in which the compressor 2 is operating with the solenoid valve 40 being in an opened state, the opened state of the solenoid valve 40 is maintained even after the compressor 2 is stopped.

A cooling device for, for example, a cooling object has a refrigerant circuit with an evaporator, in which a cold air flow for the cooling object exchanges heat with the refrigerant, and a defrosting system for de-icing the evaporator. The defrosting system is controlled according to the degree of icing of the evaporator. The degree of icing of the evaporator is determined by the control unit of the defrosting system on the basis of the temperature of the cold air flow from the cooling object to the evaporator, the temperature and/or the operating pressure of the refrigerant upstream of the evaporator and at least one operating parameter of the compressor.

This air conditioning device for a vehicle comprises: an indoor condenser; an indoor evaporator; a first expansion valve; a second expansion valve; a refrigerant line; an expansion valve control detector; and a controller. The expansion valve control detector is constituted by: only one temperature sensor that detects the temperature of refrigerant in an inter-expansion valve line of the refrigerant line; and only one pressure sensor that detects the pressure of the refrigerant in the inter-expansion valve line. During a cooling operation, the controller issues, to the first expansion valve, an opening command corresponding to a state quantity of the refrigerant that has been detected by the expansion valve control detector, and during a heating operation, the controller issues, to the second expansion valve, an opening command corresponding to a state quantity of the refrigerant that has been detected by the expansion valve control detector.

A vehicle air-conditioning device is provided which is capable of eliminating or suppressing vibration and noise generated due to the application of a counterpressure to an opening/closing valve. The vehicle air-conditioning device includes a refrigerant circuit R having a compressor 2, a radiator 4 to perform heat exchange between a refrigerant and air, an outdoor heat exchanger 7, a heat absorber 9, and a solenoid valve 40. The compressor 2 and the solenoid valve 40 are controlled to air-condition a vehicle interior. A decompression speed at a refrigerant inflow side of the solenoid valve when the compressor 2 is stopped and the solenoid valve 40 is closed is faster than that at a refrigerant outflow side thereof. When operation is stopped from a state in which the compressor 2 is operating with the solenoid valve 40 being in an opened state, the opened state of the solenoid valve 40 is maintained even after the compressor 2 is stopped.

This air conditioning device for a vehicle has: an indoor condenser; an indoor evaporator; a first expansion valve; a second expansion valve; a refrigerant line; an expansion valve control detector; and a controller. The expansion valve control detector is constituted by: only one temperature sensor that detects the temperature of refrigerant in an inter-expansion valve line of the refrigerant line; and only one pressure sensor that detects the pressure of the refrigerant in the inter-expansion valve line. During a cooling operation, the controller issues, to the first expansion valve, an opening command corresponding to a state quantity of the refrigerant that has been detected by the expansion valve control detector, and during a heating operation, the controller issues, to the second expansion valve, an opening command corresponding to a state quantity of the refrigerant that has been detected by the expansion valve control detector.

Vehicle air conditioner avoids operation when short of refrigerant or oil due to backflow of refrigerant from an outdoor expansion valve to a radiator and which previously prevents lowering of air conditioning performance or deterioration of reliability. A first operation mode sends, to radiator 4, refrigerant discharged from compressor 2. A second operation mode shuts off outdoor expansion valve 6 and sends refrigerant directly into outdoor heat exchanger 7, passing the radiator and the outdoor expansion valve with bypass device 45. In the second operation mode, based on difference Pdc between pressures on outlet and inlet sides of the outdoor expansion valve 6, a controller controls a number of revolutions of compressor 2 so that pressure difference Pdc is not in excess of a predetermined reverse pressure limit ULPdcH of outdoor expansion valve 6.

An electric valve and a thermal management system. The electric valve comprises a pressure sensing unit. The pressure sensing unit is connected to a valve seat, and the pressure sensing unit can sense the pressure characteristics of a working medium in a detection flow channel) and form a piezoelectric signal. An electric control portion comprises an electric control board. The piezoelectric signal forms, by means of a conditioning circuit, an electrical signal corresponding to a pressure. The electrical signal is used as a part for generating a signal for controlling a driving portion.

A cooling device for, for example, a cooling object has a refrigerant circuit with an evaporator, in which a cold air flow for the cooling object exchanges heat with the refrigerant, and a defrosting system for de-icing the evaporator. The defrosting system is controlled according to the degree of icing of the evaporator. The degree of icing of the evaporator is determined by the control unit of the defrosting system on the basis of the temperature of the cold air flow from the cooling object to the evaporator, the temperature and/or the operating pressure of the refrigerant upstream of the evaporator and at least one operating parameter of the compressor.

The present disclosure provides a method of controlling an air conditioning system of a vehicle. The method includes controlling a compressor to adjust a flow of refrigerant discharged from the compressor to obtain a target refrigerant pressure responsive to an actual refrigerant pressure upstream an inlet of an electric expansion valve. The method also includes controlling the valve to adjust the flow entering an evaporator to obtain a target evaporator surface temperature responsive to an actual evaporator temperature.