Provided is a combination valve unit having an improved structure and capable of performing both a pressure relief function for cooling and a pressure relief function for dehumidification. In addition, disclosed is a vehicle heat pump system capable of improving dehumidification performance by actively controlling the refrigerant flow distribution. The combination valve unit serves as a refrigerant throttling means in a vehicle heat pump system, and forms the inlet for a cooling pressure relief unit for performing indoor cooling and the inlet for a dehumidification pressure relief unit for performing indoor dehumidification, respectively.

Provided is a combination valve unit having an improved structure and capable of performing both a pressure relief function for cooling and a pressure relief function for dehumidification. In addition, disclosed is a vehicle heat pump system capable of improving dehumidification performance by actively controlling the refrigerant flow distribution. The combination valve unit serves as a refrigerant throttling means in a vehicle heat pump system, and forms the inlet for a cooling pressure relief unit for performing indoor cooling and the inlet for a dehumidification pressure relief unit for performing indoor dehumidification, respectively.

There is provided a HVAC system comprising: a fluid circuit for conveying a refrigerant; a compressor for compressing the refrigerant; three heat exchangers defining an evaporator, an outdoor exchanger and a heat recovery exchanger provided along the fluid circuit; an expansion valve provided along the fluid circuit; and a receiver connected in parallel to the expansion valve, wherein a fill valve is located between the receiver and a connection upstream of the expansion valve and a drain valve is located between the receiver and a connection downstream of the expansion valve; wherein the fluid circuit comprises a plurality of valves which are configured to be controlled based on a selected operating mode such that at least one of the outdoor exchanger and the heat recovery exchanger is connected to a discharge line of the compressor and in series with one of the other heat exchangers which is connected to a suction line of the compressor, with the expansion valve disposed between the heat exchangers; wherein the fill and drain valves are configured to be controlled to store a volume of refrigerant in the receiver so as to provide an effective refrigerant charge in the fluid circuit that corresponds to the selected operating mode.

There is provided a HVAC system comprising: a fluid circuit for conveying a refrigerant; a compressor for compressing the refrigerant; three heat exchangers defining an evaporator, an outdoor exchanger and a heat recovery exchanger provided along the fluid circuit; an expansion valve provided along the fluid circuit; and a receiver connected in parallel to the expansion valve, wherein a fill valve is located between the receiver and a connection upstream of the expansion valve and a drain valve is located between the receiver and a connection downstream of the expansion valve; wherein the fluid circuit comprises a plurality of valves which are configured to be controlled based on a selected operating mode such that at least one of the outdoor exchanger and the heat recovery exchanger is connected to a discharge line of the compressor and in series with one of the other heat exchangers which is connected to a suction line of the compressor, with the expansion valve disposed between the heat exchangers; wherein the fill and drain valves are configured to be controlled to store a volume of refrigerant in the receiver so as to provide an effective refrigerant charge in the fluid circuit that corresponds to the selected operating mode.

A cooling system includes an evaporator, connected through fluid lines to a first condenser, a second condenser, a compressor, and a thermal expansion valve. One or more valves are arranged in the fluid lines. The one or more valves operated to, in a first mode, circulate fluid between the evaporator the first condenser; in a second mode, circulate the fluid between a) the evaporator and the first condenser, and b) the evaporator, the second condenser, and the thermal expansion valve, and; in a third mode, circulate the fluid between a) the evaporator and the first condenser, and c) the evaporator, the compressor, the second condenser, and the thermal expansion valve.

A cooling system includes an evaporator, connected through fluid lines to a first condenser, a second condenser, a compressor, and a thermal expansion valve. One or more valves are arranged in the fluid lines. The one or more valves operated to, in a first mode, circulate fluid between the evaporator the first condenser; in a second mode, circulate the fluid between a) the evaporator and the first condenser, and b) the evaporator, the second condenser, and the thermal expansion valve, and; in a third mode, circulate the fluid between a) the evaporator and the first condenser, and c) the evaporator, the compressor, the second condenser, and the thermal expansion valve.

An electronic expansion valve is provided including: a valve body provided with a first port and a second port, a first cavity being defined in the valve body and being in fluid communication with the first port, the valve body also being provided with a valve port between the second port and the first cavity; a drive mechanism including a rotor having a rotor screw and a stator; a valve spindle assembly at least partially disposed in the valve body and being capable of operatively cooperating with the rotor screw for reciprocating motion to adjust the degree of opening of the valve port; and a second cavity isolated and sealed off from the first cavity, wherein a balancing passage is formed in the rotor screw and the valve spindle assembly to enable the second cavity to be in fluid communication with the second port via the balancing passage.

An electronic expansion valve is provided including: a valve body provided with a first port and a second port, a first cavity being defined in the valve body and being in fluid communication with the first port, the valve body also being provided with a valve port between the second port and the first cavity; a drive mechanism including a rotor having a rotor screw and a stator; a valve spindle assembly at least partially disposed in the valve body and being capable of operatively cooperating with the rotor screw for reciprocating motion to adjust the degree of opening of the valve port; and a second cavity isolated and sealed off from the first cavity, wherein a balancing passage is formed in the rotor screw and the valve spindle assembly to enable the second cavity to be in fluid communication with the second port via the balancing passage.

A control system and a control method, which can control an electronic expansion valve. The method comprises: acquiring a temperature signal of an electronic expansion valve outlet and a pressure signal of the electronic expansion valve outlet; determining a first current degree of superheat on the basis of the temperature signal of the electronic expansion valve outlet and the pressure signal of the electronic expansion valve outlet; and a processing unit controlling, according to the requirements of an upper computer or the requirements of a set condition, an electronic expansion value to operate one of a temperature control mode, a degree of superheat control mode and an opening control mode. The technical solution provided in the embodiments of the present invention improves the real-time performance and the accuracy of control of an electronic expansion valve.

A control system and a control method, which can control an electronic expansion valve. The method comprises: acquiring a temperature signal of an electronic expansion valve outlet and a pressure signal of the electronic expansion valve outlet; determining a first current degree of superheat on the basis of the temperature signal of the electronic expansion valve outlet and the pressure signal of the electronic expansion valve outlet; and a processing unit controlling, according to the requirements of an upper computer or the requirements of a set condition, an electronic expansion value to operate one of a temperature control mode, a degree of superheat control mode and an opening control mode. The technical solution provided in the embodiments of the present invention improves the real-time performance and the accuracy of control of an electronic expansion valve.