A refrigerant cycle apparatus includes a refrigerant circuit that circulates a refrigerant, and a leak sensor that detects a refrigerant leaking from the refrigerant circuit, in which the refrigerant cycle apparatus includes, as an operating mode, a recovery mode for recognizing occurrence of an abnormality in the leak sensor and recovering a refrigerant to a predetermined location in the refrigerant circuit.

A freezer case includes a refrigeration system and a controller. The controller is configured to store a plurality of setpoint instruction sets associated with a plurality of possible operating modes, select a current operating mode from the plurality of possible operating modes, assign a value for the superheat setpoint by executing the setpoint instruction set associated with the current operating mode, control the refrigeration system in accordance with the superheat setpoint.

Devices, systems, and methods are disclosed for cooling using both air and/or liquid cooling sub circuits. A vapor compression cooling system having both an air and liquid cooling sub circuit designed to service high sensible process heat loads that cannot be solely cooled by either liquid or air is provided.

A refrigerator includes a first compressor configured to compress first refrigerant, a first condenser configured to condense the compressed first refrigerant, a first expansion valve configured to reduce a temperature and a pressure of the condensed first refrigerant, a first evaporator configured to evaporate the first refrigerant having passed through the first expansion valve, a second compressor configured to compress second refrigerant, a second condenser configured to condense the compressed second refrigerant, a second expansion valve configured to reduce a temperature and a pressure of the condensed second refrigerant, a second evaporator configured to evaporate the second refrigerant having passed through the second expansion valve, a first heat exchanger arranged after and connected to the first expansion valve, and a second heat exchanger arranged after and connected to the second expansion valve. The first heat exchanger and the second heat exchanger are configured to exchange heat with each other.

Described is a vector control system for a vapor compression circuit. The vector control system may monitor the vapor compression circuit and adjust the speed of one or more motors to increase efficiency by taking into account the torque forces placed on a compressor motor.

An HVAC system includes a compressor, condenser, and evaporator. A sensor measures a value associated with the refrigerant in the condenser or the evaporator, and a controller is communicatively coupled to the compressor and the sensor. The controller determines, based on an operational history the compressor, that pre-requisite criteria are satisfied for entering a sensor validation mode. After determining the pre-requisite criteria are satisfied, an initial sensor measurement value is determined. Following determining the initial sensor measurement value, the compressor is operated according to a sensor-validation mode. Following operating the compressor according to the sensor-validation mode for at least a minimum time, a current sensor measurement value is determined. The controller determines whether validation criteria are satisfied for the current sensor value. In response to determining that the validation criteria are satisfied, the controller determines that the sensor is validated.

Technologies are provided for preventing a working fluid leak from pooling and thus diluting any leaked working fluid from air within a condenser and/or evaporator compartment of the CCU. This can include a computer-readable medium that stores executable instructions that, upon execution, prevent a working fluid leak from pooling within a climate-control unit (CCU) of a transport climate control system. This also includes detecting fulfillment of activation threshold conditions in connection with the CCU. Also, this includes activating a fan in at least one of a condenser unit and an evaporator unit included in the CCU to dilute leaked working fluid from air within the CCU. Further, this includes detecting fulfillment of de-activation threshold conditions and de-activation of an activated fan.

An air conditioner unit includes a variable speed compressor for circulating refrigerant through refrigeration loop and a controller configured to initiate an operating cycle, start a compressor transition timer, and determine an unfiltered compressor speed. The unfiltered compressor speed is fixed based on the selected operating mode until the compressor transition timer reaches a predetermined transition delay time, after which the unfiltered compressor speed is determined using a closed loop feedback control algorithm. The controller is further configured to operating the variable speed compressor at a target compressor speed that is modified from the unfiltered compressor speed based on the identification of a speed modification condition, such as a dehumidification deficiency a speed restriction, or the identification of one or more resonance avoidance zones.

The present disclosure generally relates refrigeration systems for temperature-controlled displays. For instance, one exemplary embodiment relates to a refrigeration system that includes a refrigeration circuit, a cooling circuit, a reclaim heat circuit, and a floor heating system. The refrigeration circuit includes a compressor driven by a brushless DC motor operable at multiple different speeds, a first heat exchanger, an expansion device, and a cooling unit in fluid communication using a first working fluid. The cooling unit is arranged to cool a temperature-controlled storage device. The cooling circuit includes a pump and a second heat exchanger in thermal communication with the first heat exchanger using a second working fluid such that the first heat exchanger is liquid-cooled by the second working fluid. The reclaim heat circuit is in fluid communication with the cooling circuit. The floor heating system is coupled to the heat reclaim circuit as a reclaim heat load.

A control method for a refrigerator includes sensing a temperature of a storage room; operating a cool air supply at a cooling power when the sensed temperature of the storage room is equal to or above a first reference temperature; operating the cool air supply at a delay power, which is less than the cooling power, when the sensed temperature of the storage room is equal to or below a second reference temperature, which is less than the first reference temperature while the cool air supply is operating at the cooling power; and adjusting the cooling power or the delay power of the cool air supply according to the temperature of the storage room while the cool air supply is operating at the delay power, and operating the cool air supply at the determined adjusted cooling power or delay power.