A system has a first compressor and a second compressor. A heat rejection heat exchanger is coupled to the first and second compressors to receive refrigerant compressed by the compressors. The system includes an economizer for receiving refrigerant from the heat rejection heat exchanger and reducing an enthalpy of a first portion of the received refrigerant while increasing an enthalpy of a second portion. The second portion is returned to the compressor. The ejector has a primary inlet coupled to the means to receive a first flow of the reduced enthalpy refrigerant. The ejector has a secondary inlet and an outlet. The outlet is coupled to the first compressor to return refrigerant to the first compressor. A first heat absorption heat exchanger is coupled to the economizer to receive a second flow of the reduced enthalpy refrigerant and is upstream of the secondary inlet of the ejector. A second heat absorption heat exchanger is between the outlet of the ejector and the first compressor.

The application provides an air-conditioning system with mixed working medium, including: a compressor, and a first heat exchanger, wherein the first heat exchanger is communicated with an exhaust port of the compressor, the first heat exchanger is provided with a first flow channel communicated with a first inlet end and a second flow channel communicated with a first outlet end, and a first gas-liquid separator is further connected between the first flow channel and the second flow channel; and the first gas-liquid separator includes a first inlet, a first liquid outlet and a first gas outlet, the first inlet is communicated with the first flow channel, the first gas outlet is communicated with the second flow channel, and a liquid flowing out of the first liquid outlet is capable of being throttled and heated and then connected to a gas supplement port of the compressor for gas supplement. The application enables more high-boiling point refrigerant working medium entering the first heat exchanger to improve condensation performance, and further increases the amount of low-boiling point refrigerant working medium entering the second heat exchanger to improve evaporation performance, thereby solving the problem of poor gas supplement effect of a gas supplement system with mixed working medium, and improving the performance of the air-conditioning system.

Refrigeration apparatus (1) having a closed circuit (C) in which a flow rate (P) of coolant circulates, said closed circuit comprising at least one main branch (M) provided with at least one main compressor (2), at least one cooling device (3) to cool said coolant, expansion means (4) to expand the coolant and at least one evaporator (5), said closed circuit further comprising at least one secondary economizer branch (100) for at least one fraction of flow rate (X1) of said coolant, wherein the inlet section (100a) of said at least one first secondary economizer branch (100) is arranged in a length (101) of said closed circuit (C) comprised between said cooling device (3) and said expansion means (4) and the outlet section (100b) of said at least one secondary economizer branch (100) is arranged in proximity of the suction of said main compressor (2), said main branch (M) further comprises at least one reciprocating compressor (6) arranged between said evaporator and said main compressor. Said at least one secondary economizer branch comprises at least one control device for diverting at least one portion (X2) of said fraction (X1) of coolant coming from said secondary economizer branch (100) to drive the reciprocating compressor.

A refrigeration system includes a receiver, a gas bypass valve, a parallel compressor, and a controller. The gas bypass valve and the parallel compressor are fluidly coupled to an outlet of the receiver in parallel and configured to control a pressure of a gas refrigerant in the receiver. The controller is configured to switch from operating the gas bypass valve to operating the parallel compressor to control the pressure of the gas refrigerant in the receiver in response to a value of a process variable crossing a switchover setpoint. The value of the process variable depends on an amount of the gas refrigerant produced by the refrigeration system. The controller is configured to automatically adjust the switchover setpoint in response to the amount of the gas refrigerant produced by the refrigeration system being insufficient to sustain operation of the parallel compressor.

The present disclosure is directed to an aircraft power generation system including a reverse Brayton cycle system, a gas turbine engine, and a gearbox. The gas turbine engine includes a compressor section, a turbine section, and an engine shaft. The compressor section is arranged in serial flow arrangement with the turbine section. The engine shaft is rotatable with at least a portion of the compressor section and with at least a portion of the turbine section. The reverse Brayton cycle system includes a compressor, a driveshaft, a turbine, and a first exchanger. The driveshaft is rotatable with the compressor or the turbine, and the compressor, the first heat exchanger, and the turbine are in serial flow arrangement. The gearbox is configured to receive mechanical energy from the engine shaft and transmit mechanical energy to the reverse Brayton cycle system through the driveshaft.

The present invention provides a cooling system (1), comprising a receiver tank (2), an evaporator (3), a compressor (4) and a gas cooler (5), wherein the receiver tank (2) comprises a fluid inlet (6), a liquid outlet (7) and a gas outlet (8); the evaporator (3) comprises an evaporator inlet (9) and an evaporator outlet (10), the compressor (4) comprises a compressor inlet (11) and a compressor outlet (12); the gas cooler (5) comprises a cooler inlet (13) and a cooler outlet (14); and the liquid outlet (7) of the receiver tank (2) is connected to the evaporator inlet (9) via a first conduit (15), the evaporator outlet (10) is connected to the compressor inlet (11) via a second conduit (16), the compressor outlet (12) is connected to the cooler inlet (13) via a third conduit (17), and the cooler outlet (14) is connected to the fluid inlet (6) of the receiver via a fourth conduit (18), wherein at least one of the first conduit (15) and the fourth conduit (18) comprises a pressure regulator (19,25), and the gas outlet (8) of the receiver tank is connected to the evaporator inlet (9) via a fifth conduit (20) and a gas flow regulator (21,22), such that a flow of liquid refrigerant in the first conduit (15) may be controlled by operating the gas flow regulator (21,22) during use.

A compressor temperature control system and method for an aircraft air cycle machine is presented. The system prevents overheating of the compressor using a low limit valve positioned between a turbine outlet and a bleed air source. The low limit valve directs the air to an air cycle machine, or bypasses the machine, in regards at least in part to the air temperature measured in the cabin supply duct.

This invention provides a regenerator material having a high specific heat, particularly in the temperature range of 10 to 25K, and a regenerator and a refrigerator comprising the regenerator material. The present invention specifically provides an HoCu-based regenerator material represented by general formula (1): HoCu.sub.2-xM.sub.x (1), wherein x is 0<x≤1, and M is at least one member selected from the group consisting of Al and transition metal elements (excluding Cu), as well as a regenerator and a refrigerator comprising the regenerator material.

This invention provides a regenerator material having a high specific heat, particularly in the temperature range of 10 to 25K, and a regenerator and a refrigerator comprising the regenerator material. The present invention specifically provides an HoCu-based regenerator material represented by general formula (1): HoCu.sub.2-xM.sub.x (1), wherein x is 0<x≤1, and M is at least one member selected from the group consisting of Al and transition metal elements (excluding Cu), as well as a regenerator and a refrigerator comprising the regenerator material.

Secondary loop air conditioning and heat pump systems include a reservoir with a capsule holding a phase change material.