An ejector refrigeration circuit 1 including: a two-phase circuit 2 including: a heat rejection heat exchanger 12 including an inlet 12a and an outlet 12b; and an ejector 14 including a high pressure inlet 14a, a low pressure inlet 14b and an outlet 14c; the ejector high pressure inlet 14a is coupled to the heat rejection heat exchanger outlet 12b; and an evaporator 18 including an inlet 18a and an outlet 18b; the outlet 18b of the evaporator 18 is coupled to the low pressure inlet 14b of the ejector 14; and the ejector refrigeration circuit 1 further including a vapour quality sensor 20 positioned at the outlet 12b of the heat rejection heat exchanger 12.

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.

The disclosure provides a heat pump cycle that allows for an improved matching of the T(Q) slopes of the heat pump cycle. More particularly, the high temperature heat exchange is separated into two stages. Furthermore, a portion of the working fluid that was cooled in the first stage, is further cooled by expansion before being mixed with a heated working fluid for input to the recuperating heat exchanger.

A switching mechanism (TV1, TV2, TV3, TV4, FV) includes an electric motor (74), a flow path switching portion (71) to be driven by the electric motor (74), a first port (P1) connected to a high-pressure flow path (7, 24, 28b, 31, 32) of a refrigerant circuit (6), a second port (P2) connected to a low-pressure flow path (8, 25, 28a, 33, 34) of the refrigerant circuit (6), and a third port (P3) connected to a predetermined flow path of the refrigerant circuit (6). The switching mechanism (TV1, TV2, TV3, TV4, FV) is switched between a first state in which the first port (P1) communicates with the third port (P3) and a second state in which the second port (P2) communicates with the third port (P3) in such a manner that the electric motor (74) drives the flow path switching portion (71).

A subcooling controller includes a sensor and a processor. The sensor measures one or more of a temperature external to a first heat exchanger that removes heat from carbon dioxide refrigerant, a temperature of the carbon dioxide refrigerant, and a pressure of the carbon dioxide refrigerant. The processor determines that one or more of the measured temperature external to the first heat exchanger, the temperature of the carbon dioxide refrigerant, and the pressure of the carbon dioxide refrigerant is above a threshold and in response to that determination, activates a subcooling system. The subcooling system includes a condenser, a second heat exchanger, and a compressor. The condenser removes heat from a second refrigerant. The second heat removes heat from the carbon dioxide refrigerant stored in a flash tank. The compressor compresses the second refrigerant from the second heat exchanger and sends the second refrigerant to the condenser.

A refrigeration system for a carbon dioxide based refrigerant fluid, wherein the refrigeration system includes a refrigerant circuit, the refrigerant circuit including a compression device, a heat rejecting heat exchanger, an ejector, a receiver, an expansion device, and a heat absorbing heat exchanger; wherein the ejector includes a primary inlet, a secondary inlet and an outlet; wherein the receiver includes an inlet, a liquid outlet and a gas outlet; wherein the ejector primary inlet is arranged to receive fluid from an outlet of the heat rejecting heat exchanger, the ejector secondary inlet is arranged to receive fluid from an outlet of the heat absorbing heat exchanger, and the ejector outlet is arranged to direct flow to the receiver inlet; wherein a suction inlet of the compression device is arranged to receive refrigerant fluid from the gas outlet of the receiver.

A refrigeration apparatus (1) includes a heat-source-side unit (10) using a refrigerant that works in a supercritical region. The heat-source-side unit (10) includes a compression element (20) configured to compress the refrigerant, a heat-source-side heat exchanger (24), an expansion valve (26) provided downstream of the heat-source-side heat exchanger (24), a receiver (25) provided downstream of the expansion valve (26), and a control unit (101). The control unit (101) performs a first operation for evaluating the amount of the refrigerant based on a high-pressure-side pressure, on a first condition that the internal pressure of the receiver (25) be equal to or less than a supercritical pressure.

A thermal management system includes a closed-circuit refrigeration system that includes a vapor cycle system (VCS) and a liquid pumping system (LPS). The VCS includes a receiver that stores a refrigerant fluid and a liquid separator. The vapor cycle system is configured to operate in one or more operational modes including at least one of a TES cooling mode, a heat load cooling mode, or a pump-down mode. The LPS includes a thermal energy storage (TES) that stores a phase change material (PCM) and a pump fluidly coupled to at least one evaporator. The evaporator is configured to extract heat from a heat load that is in thermal conductive or convective contact to the evaporator to transfer heat to the refrigerant fluid and provide the refrigerant fluid from an evaporator outlet to the TES.

The present disclosure addresses the problem of providing a refrigerant composition that has a low GWP and a refrigerating capacity equivalent to that of R404A, which is currently widely used. As a solution to the problem, the present disclosure provides a composition containing carbon dioxide and a mixture of fluorinated hydrocarbons, the mixture containing difluoromethane (R32), pentafluoroethane (R125), 2,3,3,3-tetrafluoropropene (R1234yf), 1,1,1,2-tetrafluoroethane (R134a), and carbon dioxide (CO.sub.2) in specific concentrations.

A system includes a pressure exchanger (PX). The PX is coupled to a motor that controls an operating speed of the PX. The system further includes a condenser. An outlet of the condenser is fluidly coupled to a first inlet of the PX. The system further includes a pressure gauge. The pressure gauge is configured to provide first pressure data. The first pressure data is indicative of a pressure of a fluid of the condenser. The system further includes a first controller configured to cause the motor to adjust the operating speed of the PX. The first controller causes the motor to adjust the operating speed of the PX based on the first pressure data.