Abstract: 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.

Abstract: A method includes receiving, by a processing device and from a variable frequency drive coupled to one or more compressors, operation information of the one or more compressors. The method also includes comparing the operation information of the one or more compressors to an operation threshold and determining that the operation information satisfies the operation threshold. The method also includes changing, based on the determination that the operation information of the one or more compressors satisfies the operation threshold, an operation parameter of a component of the refrigeration system. Changing the operation parameter increases at least one of: (i) a velocity of a working fluid in a piping assembly fluidly coupled to the one or more compressors, or (ii) a flow rate of an oil in the piping assembly flowing into the one or more compressors.

Abstract: A cooling system includes a distribution system and a cooling unit. The distribution system is configured to circulate a distribution system refrigerant. The distribution system includes a distribution system pump, a main cooler, a distribution system input conduit, and a distribution system output conduit. The main cooler is configured to receive the distribution system refrigerant from the distribution system pump. The distribution system input conduit is configured to receive the distribution system refrigerant from the main cooler. The distribution system output conduit is configured to receive the distribution system refrigerant from the distribution system input conduit and to provide the distribution system refrigerant to the distribution system pump. The cooling unit is configured to circulate a cooling unit refrigerant. The cooling unit includes a cooling unit pump, an upstream receiver, a condenser, a downstream receiver, and an evaporator.

Abstract: A controller for a refrigeration system includes a processing circuit having one or more processors and memory. The processing circuit is configured to calculate a superheat of a gas refrigerant exiting a first side of a subcooler based on a measured temperature and a measured pressure of the gas refrigerant and compare the calculated superheat to a superheat threshold. In response to a determination that the calculated superheat is less than the superheat threshold, the processing circuit closes an expansion valve to restrict a flow of the gas refrigerant through a second side of the subcooler. In response to a determination that the calculated superheat is equal to or greater than the superheat threshold, the processing circuit operates the expansion valve to drive a temperature of a subcooled liquid refrigerant exiting the second side of the subcooler to a subcooled liquid temperature setpoint.

Abstract: A diagnostics system for a display case includes a display case, a display device, and a remote controller, according to some embodiments. The display case includes a local controller, a refrigeration apparatus, and multiple sensors. The remote controller includes a processing circuit configured to receive diagnostics data from the local controller of the display case, according to some embodiments. The processing circuit is configured to identify one or more events using the diagnostics data and assign a rank to each of the one or more events. The processing circuit is configured to promote the rank of each of the one or more events based on an amount of time that each of the one or more events persists. The processing circuit is configured to operate the display device to notify a user regarding the one or more events and the rank of each event.

Abstract: A display case includes multiple walls that define an inner volume, a door, a door actuator, a gesture sensor, and a controller. The door is transitionable between an open position for access to the inner volume and a closed position. The door actuator is configured to transition the door between the open position and the closed position. The gesture sensor is configured to detect a gesture performed by a user. The controller includes a processing circuit configured to obtain sensor data from the gesture sensor that indicates the gesture performed by the user. The processing circuit is further configured to determine if the user has performed a reference gesture using the sensor data. The processing circuit is further configured to operate the door actuator to transition the door between the open position and the closed position in response to determining that the user has performed the reference gesture.

Abstract: A refrigeration system includes a first compressor system, a second compressor system, a first conduit, a heat exchanger, a second conduit, and a third conduit. The first compressor system includes a plurality of first compressors. The second compressor system includes a plurality of second compressors. The first conduit is configured to provide refrigerant from the first compressor system to the second compressor system. The second conduit is fluidly coupled to the first conduit and configured to provide the refrigerant from the first compressor system to the heat exchanger. The third conduit is configured to provide the refrigerant from the second compressor system to the heat exchanger.

Abstract: 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.

Abstract: A refrigerated display case chassis includes a first insulated panel and a second insulated panel. The first insulated panel has a first foam layer bounded by a first pair of thermally conductive sheets. The first insulated panel forms a first wall of the refrigerated display case chassis. The second insulated panel has a second foam layer bounded by a second pair of thermally conductive sheets. The second insulated panel forms a second wall of the refrigerated display case chassis. The second insulated panel mates with the first insulated panel to form a thermally insulated joint where, in cross-section, one sheet of the first pair of thermally conductive sheets terminates at a surface of the second foam layer. The thermally conductive sheets have a greater thermal conductivity than the first or second foam layers.

Abstract: A refrigeration system includes a refrigeration circuit and a coolant circuit separate from the refrigeration circuit. The refrigerant circuit includes a gas cooler/condenser, a receiver, and an evaporator. The coolant circuit includes a heat exchanger configured to transfer heat from a refrigerant circulating within the refrigeration circuit into a coolant circulating within the coolant circuit, a heat sink configured to remove heat from the coolant circulating within the coolant circuit, and a magnetocaloric conditioning unit configured to transfer heat from the coolant within a first fluid conduit of the coolant circuit into the coolant within a second fluid conduit of the coolant circuit. The first fluid conduit connects an outlet of the heat exchanger to an inlet of the heat sink, whereas the second fluid conduit connects an outlet of the heat sink to an inlet of the heat exchanger.

Abstract: 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.

Abstract: A thermoelectric cooling system includes a first circuit, a second circuit, a circuit heat exchanger, and a thermoelectric subsystem. The first circuit is configured to circulate a first refrigerant. The second circuit is configured to circulate a second refrigerant. The circuit heat exchanger includes a circuit heat exchanger first passage and a circuit heat exchanger second passage. The circuit heat exchanger first passage is coupled to the first circuit and configured to receive the first refrigerant from the first circuit and provide the first refrigerant to the first circuit. The circuit heat exchanger second passage is coupled to the second circuit and configured to receive the second refrigerant from the second circuit and provide the second refrigerant to the second circuit. The thermoelectric subsystem includes a thermoelectric subsystem first heat exchanger and a first thermoelectric cell. The thermoelectric subsystem first heat exchanger has a thermoelectric subsystem first heat exchanger passage.

Abstract: A controller for a refrigerated display case includes processing circuitry configured to receive operational data from multiple refrigerated display cases and an ambient temperature reading from an ambient temperature sensor. The processing circuitry is configured to determine a limp level for a rack that includes the multiple refrigerated display cases based on the operational data and the ambient temperature reading. The processing circuitry is configured to determine an operational cooling parameter for each of the multiple refrigerated display cases based on the limp level. The operational cooling parameter indicates an amount of cooling or a corresponding cooling operation for each refrigerated display case. The processing circuitry is configured to operate each of the multiple refrigerated display cases using the operational cooling parameter.

Abstract: A refrigeration system includes an evaporator, a condenser, a compressor, a capillary tube, and an expansion device. The compressor is configured to circulate a refrigerant between the evaporator and the condenser. The capillary tube is configured to receive the refrigerant from the condenser. The expansion device is configured to receive the refrigerant from the capillary tube and provide the refrigerant to the evaporator. The expansion device is adjustable to control a flow of the refrigerant through the capillary tube.

Abstract: A refrigeration system for a temperature-controlled storage device includes a refrigeration circuit that circulates a refrigerant, a separate cooling circuit that circulates a coolant, and a controller. The refrigeration circuit includes a compressor, a condenser, an expansion device, and an evaporator. The cooling circuit includes a pump, a control valve, and a heat removing device in fluid communication with the condenser via the coolant. The controller is operatively coupled to the control valve and configured to identify a coolant temperature differential setpoint, monitor a temperature of the coolant provided to the condenser by the cooling circuit, calculate a coolant temperature differential based on the temperature of the coolant provided to the condenser, and operate the control valve to modulate a flow of the coolant through the condenser to drive the coolant temperature differential to the coolant temperature differential setpoint.

Abstract: A method includes receiving, by a processing device and from a variable frequency drive coupled to one or more compressors, operation information of the one or more compressors. The method also includes comparing the operation information of the one or more compressors to an operation threshold and determining that the operation information satisfies the operation threshold. The method also includes changing, based on the determination that the operation information of the one or more compressors satisfies the operation threshold, an operation parameter of a component of the refrigeration system. Changing the operation parameter increases at least one of: (i) a velocity of a working fluid in a piping assembly fluidly coupled to the one or more compressors, or (ii) a flow rate of an oil in the piping assembly flowing into the one or more compressors.

Abstract: A refrigeration system includes a first compressor system, a second compressor system, a first conduit, a heat exchanger, a second conduit, and a third conduit. The first compressor system includes a plurality of first compressors. The second compressor system includes a plurality of second compressors. The first conduit is configured to provide refrigerant from the first compressor system to the second compressor system. The second conduit is fluidly coupled to the first conduit and configured to provide the refrigerant from the first compressor system to the heat exchanger. The third conduit is configured to provide the refrigerant from the second compressor system to the heat exchanger.

Abstract: A CO2 refrigeration system, includes a receiving tank, a condenser, a low temperature system, and a medium temperature system. The low temperature system is fluidly coupled to the receiving tank and the condenser. The low temperature system includes a plurality of low temperature evaporators, a plurality of low temperature expansion valves, a plurality of low temperature compressors, and a plurality of flexible low temperature conduits fluidly coupling the low temperature compressors to a low temperature discharge header and a low temperature suction header. The medium temperature system is fluidly coupled to the receiving tank and the low temperature system.

Abstract: Systems and methods for controlling pressure in a CO2 refrigeration system are provided. The pressure control system includes a pressure sensor, a gas bypass valve, a parallel compressor, and a controller. The pressure sensor is configured to measure a pressure within a receiving tank of the CO2 refrigeration system. The gas bypass valve is fluidly connected with an outlet of the receiving tank and arranged in series with a compressor of the CO2 refrigeration system. The parallel compressor is fluidly connected with the outlet of the receiving tank and arranged in parallel with both the gas bypass valve and the compressor of the CO2 refrigeration system. The controller is configured to receive a pressure measurement from the pressure sensor and operate both the gas bypass valve and the parallel compressor, in response to the pressure measurement, to control the pressure within the receiving tank.

Abstract: A method for reducing sweating in a temperature-controlled display device includes receiving values of an ambient temperature, a door frame temperature, and relative humidity. The method can also include estimating a value of a dewpoint temperature using the values of the ambient temperature and the relative humidity. The method can also include determining control decisions for a door frame heater of the temperature-controlled display device using the value of the dewpoint temperature and the door frame temperature, and transitioning the door frame heater between an on-state and an off-state using the control decisions to maintain the value of the door frame temperature at or above the value of the dewpoint temperature.