An air conditioner includes: an outdoor unit; a plurality of indoor units respectively including indoor heat exchangers; expansion valves respectively provided to the plurality of indoor units, the expansion valves being configured to adjust flow rates of a refrigerant in the indoor heat exchangers; and a controller for executing a refrigerant amount balance control for adjusting opening degrees of the expansion valves so that operation state amounts, with which the indoor heat exchangers exert heat exchange amounts, of the plurality of indoor units become equal to each other.

Embodiments of an accumulator for charge management are described. A fluid compression system, comprising an accumulator fluidly connected to an evaporator via a spillover port. The spillover port directs working fluid received from the evaporator to be collected and stored in the accumulator, where the stored working fluid is stored and released from the accumulator in response to an operating condition of the evaporator.

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.

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.

A hybrid controller for a thermal control unit for controlling the temperature of a device under test (DUT) is described that uses information from an in independent heat-injecting control loop as a fast-responding proxy for relative changes in DUT test head load. This information provides additional feedback to the refrigeration sub-system's controller(s), resulting in achieving the overall system goal of temperature control of the DUT over a wide range of set point temperatures and the rapidly changing DUT head load.

An evaporator includes a cold plate configured to extract heat from one or more heat loads in proximity to the evaporator. The cold plate includes a housing, and a plurality of channels disposed through the housing, with at least one of the plurality of channels being a meandered channel.

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.

Embodiments of the present disclosure are directed toward purge units of vapor compression systems, and methods of control thereof, that improve efficiency by selectively activating and deactivating the purge unit in response to one or more conditions to, for example, enable refrigerant-to-air ratios within the purge unit within certain industry standards while still minimizing the durations of the purge cycles. For example, in certain embodiments, these conditions may include conditions within the chiller condenser, time since last purge activation, time since last venting of non-condensables, and combinations thereof. By reducing an amount of time that the purge unit would be active without removing a substantial amount non-condensables from the vapor compression system, present embodiments reduce the power consumption of the purge unit, as well as the vapor compression system as a whole, while still being responsive to prevent or mitigate a loss of efficiency due to a substantial accumulation of non-condensables in the condenser of the vapor compression system.

A test chamber and a method for conditioning air in a temperature-insulated test space of a test chamber, which is sealable against an environment and serves for receiving test material, a temperature ranging from −20° C. to +180° C. being produced within the test space by means of a cooling device of a temperature control device of the test chamber, using a cooling circuit with carbon dioxide (CO.sub.2) as a cooling agent, using a heat exchanger in the test space, using a low-pressure compressor and using a high-pressure compressor downstream of the low-pressure compressor, using a gas cooler, using a storage means for the cooling agent and using an expansion valve, the temperature in the test space being controlled and/or regulated by means of a control device of the test chamber. A gaseous and/or liquid cooling agent is dosed in the storage means by means of a high-pressure valve of the cooling circuit downstream of the gas cooler, the storage means being connected to a medium-pressure side of the cooling circuit upstream of the high-pressure compressor and downstream of the low-pressure compressor via a medium-pressure bypass of the cooling circuit, the gaseous cooling agent being dosed in the medium-pressure side from the storage means by means of a medium-pressure valve when the low-pressure compressor is switched off.

Provided is grease capable of suppressing a decrease in a function as a lubricant even when used in a device installed in a refrigerant circuit in which a refrigerant containing a chlorine atom and an olefin bond in a molecule flows, and a refrigeration cycle apparatus using the grease as a lubricant. Grease that is used in a device installed in a refrigerant circuit in which a refrigerant containing a chlorine atom and an olefin bond in a molecule flows contains fluorine as a component. In a chiller apparatus, the grease is used as a lubricant for at least one of a first radial touchdown bearing and a second radial touchdown bearing of a compressor, a drive portion of an inlet guide vane of the compressor, and a drive portion of an expansion valve.