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 vapor compression system includes a first conduit fluidly coupling a liquid collection portion of a condenser and an evaporator, where the first conduit is configured to direct a first flow of refrigerant from the condenser to a first inlet of the evaporator and a second conduit fluidly coupling the liquid collection portion of the condenser and the evaporator, where the second conduit is configured to direct a second flow of refrigerant from the condenser to a second inlet of the evaporator via gravitational force, and where the first inlet is disposed above the second inlet relative to a vertical dimension of the evaporator.

A vapor compression system includes a first conduit fluidly coupling a liquid collection portion of a condenser and an evaporator, where the first conduit is configured to direct a first flow of refrigerant from the condenser to a first inlet of the evaporator and a second conduit fluidly coupling the liquid collection portion of the condenser and the evaporator, where the second conduit is configured to direct a second flow of refrigerant from the condenser to a second inlet of the evaporator via gravitational force, and where the first inlet is disposed above the second inlet relative to a vertical dimension of the evaporator.

A subcooler is made up of a plate type heat exchanger. The accumulator is located between a compressor and the subcooler in a width direction of an outdoor unit in a planar view. The subcooler overlaps with the accumulator in the width direction in the planar view. As a result, a compact heat pump can be provided when the subcooler is a plate type heat exchanger.

A subcooler is made up of a plate type heat exchanger. The accumulator is located between a compressor and the subcooler in a width direction of an outdoor unit in a planar view. The subcooler overlaps with the accumulator in the width direction in the planar view. As a result, a compact heat pump can be provided when the subcooler is a plate type heat exchanger.

A special-shaped tube cooling and heat dissipation system includes a cooling module including a cooling chip, a liquid cooling tube, a cooling fin block and a first fan for generating cold air, a heat dissipation module including a radiator with heat pipes and a second fan, and a piping system. Through the piping system, the heat of the cooling module is transported to the radiator through the liquid, and then the heat in the liquid is discharged, and the liquid is recirculated back to the cooling module. The liquid cooling pipe and the heat pipes are flat tubes extruded from aluminum alloy to increase the heat dissipation area, each defining therein a plurality of flow channels. The liquid cooling tube and the heat pipes are respectively combined with flow guide devices that connect the heat pipes in series to form a circulating heat dissipation flow channel.

A special-shaped tube cooling and heat dissipation system includes a cooling module including a cooling chip, a liquid cooling tube, a cooling fin block and a first fan for generating cold air, a heat dissipation module including a radiator with heat pipes and a second fan, and a piping system. Through the piping system, the heat of the cooling module is transported to the radiator through the liquid, and then the heat in the liquid is discharged, and the liquid is recirculated back to the cooling module. The liquid cooling pipe and the heat pipes are flat tubes extruded from aluminum alloy to increase the heat dissipation area, each defining therein a plurality of flow channels. The liquid cooling tube and the heat pipes are respectively combined with flow guide devices that connect the heat pipes in series to form a circulating heat dissipation flow channel.

A compressor includes: a first cylinder, the first cylinder being provided with a first gas intake and a first gas outlet, the first air outlet being connected to a predetermined heat exchanger; a second cylinder, the second cylinder being provided with a second gas intake and a second gas outlet, and the second gas outlet being connected to the predetermined heat exchanger; and a gas pre-exhausting device. The gas pre-exhausting device is provided on a cylinder block of the first cylinder or on an upper end surface of the first cylinder or a lower end surface of the first cylinder; the gas pre-exhausting device includes a gas pre-exhausting port and a first control valve controlling the gas pre-exhausting port to be open or closed; and the gas pre-exhausting port is connected to the second gas intake. Further disclosed is an air conditioner system including the compressor.

A compressor includes: a first cylinder, the first cylinder being provided with a first gas intake and a first gas outlet, the first air outlet being connected to a predetermined heat exchanger; a second cylinder, the second cylinder being provided with a second gas intake and a second gas outlet, and the second gas outlet being connected to the predetermined heat exchanger; and a gas pre-exhausting device. The gas pre-exhausting device is provided on a cylinder block of the first cylinder or on an upper end surface of the first cylinder or a lower end surface of the first cylinder; the gas pre-exhausting device includes a gas pre-exhausting port and a first control valve controlling the gas pre-exhausting port to be open or closed; and the gas pre-exhausting port is connected to the second gas intake. Further disclosed is an air conditioner system including the compressor.