A refrigeration system includes a primary refrigeration circuit configured to circulate a CO.sub.2 primary refrigerant and a secondary refrigeration circuit separate from the primary refrigeration circuit. The primary refrigeration circuit includes a compressor assembly, a condenser assembly, a receiver, and one or more refrigeration loads having an evaporator assembly. The secondary refrigeration circuit includes a thermal storage unit and a heat exchanger. The thermal storage unit contains a phase change material. The secondary refrigeration circuit is in thermal communication with the primary refrigeration circuit through the heat exchanger. The primary refrigerant includes a critical temperature. The primary refrigeration circuit is configured for subcritical operation. The primary refrigeration circuit and the secondary refrigeration circuit are configured such that the phase change material provides cooling to the primary refrigerant during a first operating condition. The phase change material is configured to maintain subcritical operation of the primary refrigeration circuit during the first operating condition when the primary refrigerant is above the critical temperature.

A cooling system is provided and includes a compressor, an expansion valve, a gas cooler through which a refrigerant received from the compressor passes toward the expansion valve in a supercritical state, an evaporator interposed between the expansion valve and the compressor and a vapor sorption subcooling system. The vapor sorption subcooling system includes a desorber disposed to remove heat from refrigerant flowing from the gas cooler toward the expansion valve.

A system and method are provided including a system controller for a refrigeration or HVAC system having a compressor rack with a compressor and a condensing unit with a condenser fan. The system controller monitors and controls operation of the refrigeration or HVAC system. A rack controller monitors and controls operation of the compressor rack and determines compressor rack power consumption data. A condensing unit controller monitors and controls operation of the condensing unit and determines condensing unit power consumption data. The system controller receives the compressor rack power consumption data and the condensing unit power consumption data, determines a total power consumption of the refrigeration or HVAC system, determines a predicted power consumption or a benchmark power consumption for the refrigeration system, compares the total power consumption with the predicted power consumption or the benchmark power consumption, and generates an alert based on the comparison.

A system includes a high side heat exchanger, a flash tank, a first load, a second load, a first compressor, and a heat exchanger. The flash tank is configured to store the refrigerant from the high side heat exchanger. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The first compressor is configured to compress the refrigerant from the first load. The heat exchanger is configured to transfer heat from the refrigerant from the first compressor and the second load to the refrigerant from the high side heat exchanger, and direct the refrigerant from the first compressor and the second load to a second compressor.

A refrigeration system for a temperature-controlled storage device includes a refrigeration circuit, a cooling circuit, and a controller. 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 via a first working fluid. The cooling circuit includes a pump and a second heat exchanger in fluid communication with the first heat exchanger via a second working fluid such that the first heat exchanger is liquid-cooled by the second working fluid. The controller operates the brushless DC motor at multiple different speeds to accommodate multiple different thermal loads experienced by the refrigeration system. Each of the speeds corresponds to a different thermal load. The controller modulates the speed of the brushless DC motor to maintain a desired temperature of a temperature-controlled space within the temperature-controlled device.

A ventilation system comprises a plurality of axial fan units, each having at least one axial fan having a rotational axis generally parallel to a downstream flow caused by the axial fan, and at least one grill positioned adjacent to the at least one axial fan in a downstream flow path of the axial fan unit, the at least one grill directing an air flow of the axial fan. At least a first series of the plurality of axial fan units is adapted to be positioned at a top of a plenum arrangement extending from a bottom front of a refrigerated enclosure, to a rear back of the refrigerated enclosure, said top being at a top of the rear back. At least a second series of the plurality of axial fan units is adapted to be positioned above an area to cool and oriented to project its downstream flow in a downward direction to direct its downstream flow to said area to cool. The first series of the plurality of axial fan units is oriented to project its downstream flow in an upward direction toward the second series of the plurality of axial fan units such that the first series is adapted to direct air from the plenum arrangement to the second series.

A transcritical R-744 refrigeration system comprising at least one first compressor for compressing an R-744 refrigerant, a gas cooler for cooling the R-744 refrigerant compressed by the at least one first compressor, a throttling device for decreasing the pressure of the cooled R-744 refrigerant, a receiver for separating the R-744 refrigerant, a first heat exchanger for exchanging heat between the cooled R-744 refrigerant and the R-744 vapors separated by the receiver before the R-744 vapors are transported to the at least one first compressor, and an integrated R-744 refrigerant-based air-conditioning assembly comprising a second plurality of compressors and an air conditioner comprising a second heat exchanger and an evaporator, wherein the system is operatable in a dehumidification mode wherein the R-744 vapors exiting the gas cooler are fed through the second heat exchanger to heat and dehumidify the passing ambient air before being fed to the receiver.

A refrigeration apparatus has a refrigerant circuit formed by connecting a compressor, a condenser, an expansion valve, and an evaporator by a refrigerant pipe. The refrigeration apparatus includes a temperature duration time measuring unit, and a target evaporation temperature calculating unit. The temperature duration time measuring unit measures a high-temperature duration time in a thermo-off state, the high-temperature duration time being time during which the temperature of the interior of a to-be-cooled space is higher than a lowering threshold which is set with reference to a target interior temperature. The target evaporation temperature calculating unit updates the target evaporation temperature by decreasing the target evaporation temperature by a set subtraction coefficient, after the high-temperature duration time becomes greater than or equal to an update reference time.

The present invention provides a refrigerant composition comprising: (a) from about 65% by weight to about 90% by weight of HFO-1234ze(E); (b) from about 10% by weight to about 35% by weight of HFO-1336mzz (E); and optionally (c) from about 0% to about 4.4% by weight of HFC-227ea for use in a variety of refrigeration applications, including air conditioning and/or refrigeration and particularly cooling products such as fruits, vegetables and beverages without exposing those articles to temperatures below the freezing point of water.

A refrigeration system includes first and second compressors and an oil separator. The oil separator includes an inlet for receiving refrigerant and oil from the first compressor, a refrigerant outlet, and an oil outlet. The oil separator separates the oil from the refrigerant. A portion of the oil separator below a horizontal plane intersecting the refrigerant outlet collects separated oil and has a volume equal to a first compressor oil supply. The first compressor oil supply is greater than or equal to 100% and less than or equal to 250% of a first compressor initial oil charge. The first compressor receives oil from the oil outlet when an amount of oil in the portion is less than or equal to the first compressor oil supply. The second compressor receives oil from the refrigerant outlet when the amount of oil in the portion is greater than the first compressor oil supply.