An attachment structure includes expansion valves used in a vehicle, and a housing to which the expansion valves are attached. The housing includes a flow path through which heat medium circulating in a heat pump cycle of an air conditioner of the vehicle flows, and the flow path is opened and closed by the expansion valves.

A refrigerated display case having a housing defining a temperature controlled space and a refrigeration system coupled to the housing is provided. The refrigeration system is configured to be operable to affect a temperature of the temperature controlled space. The refrigeration system includes an actuator, a controller, and a sensor. The controller is configured to continuously update a stored position of the actuator based on measurement of an electric current provided to the actuator, retrieve the stored position after a power failure, and restart control based on the stored position of the actuator. The sensor is configured to communicate with the controller.

A refrigerated display case having a housing defining a temperature controlled space and a refrigeration system coupled to the housing is provided. The refrigeration system is configured to be operable to affect a temperature of the temperature controlled space. The refrigeration system includes an actuator, a controller, and a sensor. The controller is configured to continuously update a stored position of the actuator based on measurement of an electric current provided to the actuator, retrieve the stored position after a power failure, and restart control based on the stored position of the actuator. The sensor is configured to communicate with the controller.

An air conditioner may include a compressor that compresses refrigerant; a condenser that condenses the refrigerant; at least one expansion valve that expands the refrigerant; a gas-liquid separator that separates and discharges the refrigerant into gas refrigerant and liquid refrigerant; an evaporator that evaporates the liquid refrigerant discharged from the gas-liquid separator; a refrigerant inflow pipe that connects the expansion valve and the gas-liquid separator; a bypass pipe that connects the gas-liquid separator and the compressor; and a refrigerant discharge pipe that connects the gas-liquid separator and the evaporator. The gas-liquid separator may include a housing in which a portion of the refrigerant inflow pipe, the bypass pipe, and the refrigerant discharge pipe may be disposed, and first and second partition walls disposed in the housing.

An air conditioner may include a compressor that compresses refrigerant; a condenser that condenses the refrigerant; at least one expansion valve that expands the refrigerant; a gas-liquid separator that separates and discharges the refrigerant into gas refrigerant and liquid refrigerant; an evaporator that evaporates the liquid refrigerant discharged from the gas-liquid separator; a refrigerant inflow pipe that connects the expansion valve and the gas-liquid separator; a bypass pipe that connects the gas-liquid separator and the compressor; and a refrigerant discharge pipe that connects the gas-liquid separator and the evaporator. The gas-liquid separator may include a housing in which a portion of the refrigerant inflow pipe, the bypass pipe, and the refrigerant discharge pipe may be disposed, and first and second partition walls disposed in the housing.

An EXV (electronic expansion valve) control system includes an EXV controller for controlling an EXV within the refrigerant loop of an HVAC system. The EXV controller implements a master control algorithm that includes a plurality of sub-control algorithms and an initial series of branching decision points to determine the current mode of operation and to execute select sub-control algorithms corresponding to the current mode of operation, while not executing the sub-control algorithms corresponding to the other modes of operation. The sub-control algorithms implement various combinations of PID (Proportional Integral Derivative) control and feed-forward control, the results of which can be mapped to specific control instructions for the EXV.

An EXV (electronic expansion valve) control system includes an EXV controller for controlling an EXV within the refrigerant loop of an HVAC system. The EXV controller implements a master control algorithm that includes a plurality of sub-control algorithms and an initial series of branching decision points to determine the current mode of operation and to execute select sub-control algorithms corresponding to the current mode of operation, while not executing the sub-control algorithms corresponding to the other modes of operation. The sub-control algorithms implement various combinations of PID (Proportional Integral Derivative) control and feed-forward control, the results of which can be mapped to specific control instructions for the EXV.

A refrigeration system includes an evaporator configured to receive a flow of refrigerant and transfer heat into the refrigerant within the evaporator to provide cooling for a temperature-controlled space, an expansion valve operable to modulate the flow of refrigerant into the evaporator, a liquid level sensor configured to measure a level of liquid accumulated within a component of the refrigeration system, and a controller configured to operate the expansion valve to increase the flow of refrigerant into the evaporator or decrease the flow of refrigerant into the evaporator based on the level of liquid measured by the liquid level sensor.

A refrigeration system includes an evaporator configured to receive a flow of refrigerant and transfer heat into the refrigerant within the evaporator to provide cooling for a temperature-controlled space, an expansion valve operable to modulate the flow of refrigerant into the evaporator, a liquid level sensor configured to measure a level of liquid accumulated within a component of the refrigeration system, and a controller configured to operate the expansion valve to increase the flow of refrigerant into the evaporator or decrease the flow of refrigerant into the evaporator based on the level of liquid measured by the liquid level sensor.

A refrigeration appliance, especially domestic refrigeration appliance, includes a compressor, a condenser, at least a first evaporator, a suction line from the first evaporator to the compressor, at least one heat exchanger switchable between condenser operation and evaporator operation, and a valve arrangement switching the heat exchanger between an evaporator operating state, having a switchable heat exchanger inlet connected to the condenser through a first choke point and a switchable heat exchanger outlet connected to the first evaporator, and a condenser operating state, having the switchable heat exchanger outlet connected to the evaporator through a second choke point. A first supply line for supplying refrigerant in the evaporator operating state and a second supply line, separate therefrom, for supplying refrigerant in the condenser operating state, are associated with the switchable heat exchanger. Only the first supply line is connected with the suction line, forming an external heat exchanger.