A HVAC system having an indoor heat exchanger having a first refrigerant passage extending in a first direction and a second refrigerant extending in a second direction opposite from the first direction, a first refrigerant circuit comprising a first compressor, a first expansion valve, a first outdoor heat exchanger, the first refrigerant passage, and a first reversing valve operable to control a direction of first refrigerant in the first refrigerant circuit, and a second refrigerant circuit comprising a second compressor, a second expansion valve, a second outdoor heat exchanger, the second refrigerant passage, and a second reversing valve operable to control a direction of second refrigerant in the second refrigerant circuit.

A refrigerant cycle device includes a compressor, a radiator, a first expansion valve, a second expansion valve, a first evaporator, a second evaporator, and a controller. The controller is configured to switch between a first evaporator priority control and a second evaporator priority control. During the first evaporator priority control, the controller controls a throttle opening of the second expansion valve based on at least one of a temperature of a first evaporator, a temperature of a refrigerant flowing through the first evaporator, and a temperature of an air having exchanged heat in the first evaporator. During the second evaporator priority mode, the controller controls the throttle opening based on a refrigerant state of the second evaporator. When the at least one of the temperatures is equal to or greater than a switching temperature, the second priority mode is switched to the first priority mode.

A refrigerant cycle device includes a compressor, a radiator, a first expansion valve, a second expansion valve, a first evaporator, a second evaporator, and a controller. The controller is configured to switch between a first evaporator priority control and a second evaporator priority control. During the first evaporator priority control, the controller controls a throttle opening of the second expansion valve based on at least one of a temperature of a first evaporator, a temperature of a refrigerant flowing through the first evaporator, and a temperature of an air having exchanged heat in the first evaporator. During the second evaporator priority mode, the controller controls the throttle opening based on a refrigerant state of the second evaporator. When the at least one of the temperatures is equal to or greater than a switching temperature, the second priority mode is switched to the first priority mode.

A method of detecting electrical failure in a refrigeration system is provided. The method includes determining whether a present superheat of the refrigeration system is between a maximum superheat and a minimum superheat for the refrigeration system, the maximum superheat and the minimum superheat defining a normal operating range. The method also includes detecting an electrical property of an expansion valve assembly of the refrigeration system responsive to the superheat being outside the normal operating range. The method further includes determining whether the expansion valve assembly as experienced an electrical failure based on at least the electrical property. A signal indicating that the expansion valve has experienced an electrical failure is generated based on a determination that the expansion valve assembly has experienced the electrical failure.

A method of detecting electrical failure in a refrigeration system is provided. The method includes determining whether a present superheat of the refrigeration system is between a maximum superheat and a minimum superheat for the refrigeration system, the maximum superheat and the minimum superheat defining a normal operating range. The method also includes detecting an electrical property of an expansion valve assembly of the refrigeration system responsive to the superheat being outside the normal operating range. The method further includes determining whether the expansion valve assembly as experienced an electrical failure based on at least the electrical property. A signal indicating that the expansion valve has experienced an electrical failure is generated based on a determination that the expansion valve assembly has experienced the electrical failure.

A vapor compression system including: a condenser; an evaporator; and an expansion control system on the main flowpath between the condenser and the evaporator, wherein the expansion control system further includes: one or more electronic expansion valves; and a modulated ball valve.

A vapor compression system including: a condenser; an evaporator; and an expansion control system on the main flowpath between the condenser and the evaporator, wherein the expansion control system further includes: one or more electronic expansion valves; and a modulated ball valve.

A cooling device comprising a cooling circuit, is described. The cooling circuit further comprises a compressor adapted to compress cooling agent present in the cooling circuit during an active cooling mode, wherein the compressed cooling agent contains lubricant oil from the compressor; a condensing unit connected to the compressor by a first fluid line of the cooling circuit; and an evaporating unit, which is connected to the condensing unit by a second fluid line of the cooling circuit. The cooling circuit further comprises an expansion device arranged in the second fluid line; and an additional evaporator connected to the evaporating unit by a third fluid line of the cooling circuit, and connected to the compressor by a fourth fluid line of the cooling circuit.

A cooling device comprising a cooling circuit, is described. The cooling circuit further comprises a compressor adapted to compress cooling agent present in the cooling circuit during an active cooling mode, wherein the compressed cooling agent contains lubricant oil from the compressor; a condensing unit connected to the compressor by a first fluid line of the cooling circuit; and an evaporating unit, which is connected to the condensing unit by a second fluid line of the cooling circuit. The cooling circuit further comprises an expansion device arranged in the second fluid line; and an additional evaporator connected to the evaporating unit by a third fluid line of the cooling circuit, and connected to the compressor by a fourth fluid line of the cooling circuit.

An air conditioning apparatus includes a heat exchange device that connects an outdoor unit to an indoor unit and that includes a heat exchanger configured to perform heat exchange between refrigerant and water. The heat exchanger reduces an amount of refrigerant used to perform a cooling operation or a heating operation.