Abstract: A system (20; 300) comprises: a vapor compression loop (38; 338); a low-pressure or medium-pressure refrigerant in the loop; a centrifugal compressor (42) along the vapor compression loop and comprising: a housing (120); an inlet (44); an outlet (46); an impeller (140); an electric motor (122) coupled to the impeller to drive rotation of the impeller; and one or more refrigerant-lubricated bearings (130, 132).

Abstract: A moisture separating system includes a first heat pump, a liquid source in thermal communication with a heat absorption section of the heat pump, and a source of a gas to be treated. The system also includes a hydrophilic nanoporous membrane comprising a first side that receives a flow of gas from the gas source and a second side that receives a flow of liquid from the liquid source.

Abstract: A vapor compression system (200; 400; 600; 700; 800; 900; 1000) comprises a plurality of valves (260, 262, 264; 260) controllable to define a first mode flowpath and a second mode flowpath. The first mode flowpath is sequentially through: a compressor (22); a first heat exchanger (30); a first nozzle (228; 624); and a separator (48), and then branching into: a first branch returning to the compressor; and a second branch passing through an expansion device (70) and a second heat exchanger (64) to the rejoin the flowpath between the first heat exchanger and the separator. The second mode flowpath is sequentially through: the compressor; the second heat exchanger; a second nozzle (248; 625); and the separator, and then branching into: a first branch returning to the compressor; and a second branch passing through the expansion device and first heat exchanger to the rejoin the flowpath between the first heat exchanger and the separator.

Abstract: A vapor compression system (200; 300; 400) comprising: a compressor (22); a first heat exchanger (30); a second heat exchanger (64); an ejector (38); separator (48); and an expansion device (70). A plurality of conduits are positioned to define a first flowpath sequentially through: the compressor; the first heat exchanger; the ejector from a motive flow inlet through (40) an outlet (44); and the separator, and then branching into: a first branch returning to the compressor; and a second branch passing through the expansion device and second heat exchanger to a secondary flow inlet (42). The plurality of conduits are positioned to define a bypass flowpath (202; 302; 402) bypassing the motive flow inlet and rejoining the first flowpath at essentially separator pressure but away from the separator.

Abstract: A method of operating a heat transfer system includes starting operation of a first heat transfer fluid vapor/compression circulation loop including a fluid pumping mechanism, a heat exchanger for rejecting thermal energy from a first heat transfer fluid, and a heat absorption side of an internal heat exchanger. A first conduit in a closed fluid circulation loop circulates the first heat transfer fluid therethrough. Operation of a second two-phase heat transfer fluid circulation loop is started after starting operation of the first heat transfer fluid circulation loop. The second heat transfer fluid circulation loop transfers heat to the first heat transfer fluid circulation loop through the internal heat exchanger and includes a heat rejection side of the internal heat exchanger, a liquid pump, and a heat exchanger evaporator. A second conduit in a closed fluid circulation loop circulates a second heat transfer fluid therethrough.

Abstract: An HVAC/R system configured to receive power from a main power source is provided. The HVAC/R system includes an HVAC/R component configured to contain a refrigerant and allow a refrigerant to flow therethrough, a detecting mechanism configured to detect a concentration of the refrigerant outside of the HVAC/R component, and a blower configured to operate under power from an auxiliary power source upon detection of the refrigerant above a predetermined refrigerant level during a main power source outage.

Abstract: Disclosed is a refrigeration system including a heat transfer fluid circulation loop configured to allow a refrigerant to circulate therethrough. A purge gas outlet is in operable communication with the heat transfer fluid circulation loop. The system also includes at least one gas permeable membrane having a first side in operable communication with the purge gas outlet and a second side. The membrane includes a porous inorganic material with pores of a size to allow passage of contaminants through the membrane and restrict passage of the refrigerant through the membrane. The system also includes a permeate outlet in operable communication with a second side of the membrane.

Abstract: A cooling system for electrical and optical devices includes an electrocaloric cooler (EEC). A fluid circuit is in thermal communication with the EEC to dump heat from a working fluid of the fluid circuit into the EEC. The system can include a second EEC, a second fluid circuit in thermal communication with the second EEC to dump heat from a working fluid of the second fluid circuit into the EEC, and a second heat sink in thermal communication with the second fluid circuit to dump heat into the working fluid of the second fluid circuit. The second EEC, second fluid circuit, and second heat sink can be cascaded with the first EEC, first heat sink, and first fluid circuit wherein the second heat sink is in thermal communication with the first EEC to accept heat therefrom.

Abstract: A system (170) has a compressor (22). A heat rejection heat exchanger (30) is coupled to the compressor to receive refrigerant compressed by the compressor. A non-controlled ejector (38) has a primary inlet coupled to the heat rejection exchanger to receive refrigerant, a secondary inlet, and an outlet. The system includes means (172, e.g., a nozzle) for causing a supercritical-to-subcritical transition upstream of the ejector.

Abstract: A heat transfer system having a heat transfer fluid circulation loop of a first fluid is disclosed. A conduit is disposed in the fluid circulation loop with an inner surface in contact with the first fluid at a first pressure. An outer surface of the first conduit is in contact with a second fluid at a second pressure that is 69 kPa to 13771 kPa (10 psi to 2000 psi) higher than the first pressure. The conduit also includes a polyurea coating on its outer surface.

Abstract: A heat transfer system cycles between a first mode where a heat transfer fluid is directed to a first electrocaloric module and from the first electrocaloric module to a heat exchanger to a second electrocaloric module while one of the first and second electrocaloric modules is energized, and a second mode where the heat transfer fluid is directed to the second electrocaloric module and from the second electrocaloric module to the heat exchanger to the first electrocaloric module, while the other of the first and second electrocaloric modules is energized. The modes are repeatedly cycled in alternating order directing the heat transfer fluid to cause a temperature gradient in each of the first and second electrocaloric modules, and fluid from a flow path between the electrocaloric modules is mixed with circulating fluid from a conditioned space to cool or heat the conditioned space.

Abstract: A heat transfer system cycles between a first mode where a heat transfer fluid is directed to a first electrocaloric module and from the first electrocaloric module to a heat exchanger to a second electrocaloric module while one of the first and second electrocaloric modules is energized, and a second mode where the heat transfer fluid is directed to the second electrocaloric module and from the second electrocaloric module to the heat exchanger to the first electrocaloric module, while the other of the first and second electrocaloric modules is energized. The modes are repeatedly cycled in alternating order directing the heat transfer fluid to cause a temperature gradient in each of the first and second electrocaloric modules, and heat is rejected to the fluid from the heat exchanger or is absorbed by the heat exchanger from the fluid.

Abstract: In one aspect, a refrigeration system is provided. The refrigeration system includes a refrigeration circuit configured to condition an air supply, a subcooling circuit configured to cool the refrigeration circuit, the subcooling circuit including a subcooling condenser, a subcooling heat exchanger, and at least one adsorption bed, and a heat generation system thermally coupled to the subcooling circuit.

Abstract: Heat pump cycle provided with a fluidic loop connecting two heat exchangers. The fluidic loop is filled with an electro-caloric liquid as a heat transfer medium. Applying electric filed in one of the heat exchangers the temperature of the electro-caloric liquid is changed.

Abstract: A system has a compressor, a heat rejection heat exchanger, first and second ejectors, first and second heat absorption heat exchangers, and a separator. The ejectors each have a primary inlet coupled to the heat rejection exchanger to receive refrigerant. A second heat absorption heat exchanger is coupled to the outlet of the second ejector to receive refrigerant. The separator has an inlet coupled to the outlet of the first ejector to receive refrigerant from the first ejector. The separator has a gas outlet coupled to the secondary inlet of the second ejector to deliver refrigerant to the second ejector. The separator has a liquid outlet coupled to the secondary inlet of the first ejector via the first heat absorption heat exchanger to deliver refrigerant to the first ejector.

Abstract: A system (200; 250; 270) has first (220) and second (222) compressors, a heat rejection heat exchanger (30), first (38) and second (202) ejectors, a heat absorption heat exchanger (64), and a separator (48). The heat rejection heat exchanger is coupled to the second compressor to receive refrigerant compressed by the second compressor. The first ejector has a primary inlet (40) coupled to the heat rejection exchanger to receive refrigerant, a secondary inlet (42), and an outlet (44). The second ejector has a primary inlet (204) coupled to the heat rejection heat exchanger to receive refrigerant, a secondary inlet (206), and an outlet (208). The separator has an inlet (50) coupled to the outlet (44) of the first ejector to receive refrigerant from the first ejector. The separator has a gas outlet (54) coupled to the secondary inlet (206) of the second ejector via the first compressor (220) to deliver refrigerant to the second ejector.

Abstract: A vapor compression system (200; 400; 600; 700; 800; 900; 1000) comprises a plurality of valves (260, 262, 264; 260) controllable to define a first mode flowpath and a second mode flowpath. The first mode flowpath is sequentially through: a compressor (22); a first heat exchanger (30); a first nozzle (228; 624); and a separator (48), and then branching into: a first branch returning to the compressor; and a second branch passing through an expansion device (70) and a second heat exchanger (64) to the rejoin the flowpath between the first heat exchanger and the separator. The second mode flowpath is sequentially through: the compressor; the second heat exchanger; a second nozzle (248; 625); and the separator, and then branching into: a first branch returning to the compressor; and a second branch passing through the expansion device and first heat exchanger to the rejoin the flowpath between the first heat exchanger and the separator.

Abstract: A system (20; 300; 500) comprises: a compressor (22) having a suction port (40) and a discharge port (42); an ejector (32) having a motive flow inlet (50), a suction flow inlet (52), and an outlet (54); a separator (34) having an inlet (72), a vapor outlet (74), and a liquid outlet (76); a first heat exchanger (24); at least one expansion device (28, 30; 520); a second heat exchanger (26); and a plurality of conduits and a plurality of valves (100, 120, 130, 140, 144, 148, 150; 100, 140, 144, 148, 150, 320, 340; 100, 120, 530). The conduits and valves are positioned to provide alternative operation in: a cooling mode; a first heating mode wherein the ejector has a motive flow and a suction flow and where utilizing a first expansion device (30; 520) of the at least one expansion device; and a second heating mode utilizing the first expansion device and wherein the ejector has a suction flow and essentially no motive flow.

Abstract: A cooling system includes a main closed-loop refrigerant circuit having a compressor and a condenser. The cooling system also includes a subcooler closed-loop refrigerant circuit having a compressor and a condenser. A portion of the condenser of the subcooler circuit is in parallel with the condenser of the main circuit with respect to air flow. A single exhaust fan can be in fluid communication with both the condenser of the main circuit and the condenser of the subcooler circuit.

Abstract: An HVAC&R system is provided. The system includes a first pumping device configured to circulate a first volume of a first two-phase medium, a second pumping device configured to circulate a second volume of the first two-phase medium, a first plurality of secondary HVAC&R units, wherein at least one of the first plurality of secondary HVAC&R units is operably coupled to the first pumping device, a second plurality of secondary HVAC&R units, wherein at least one of the second plurality of secondary HVAC&R units is operably coupled to the second pumping device, a first primary HVAC&R unit operably coupled to at least one of the first plurality of secondary HVAC&R units and the first pumping device, and a second primary HVAC&R unit operably coupled to at least one of the second plurality of secondary HVAC&R units and the second pumping device.