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.

Refrigeration systems are described. The systems include a compression device, a heat rejecting heat exchanger, an ejector, and first and second expansion devices with respective heat absorbing heat exchangers. The ejector is arranged to receive refrigerant fluid from the heat rejecting heat exchanger at a high pressure inlet of the ejector. Fluid pathways extend from an outlet of the ejector into a branched flow path to provide flows of refrigerant from the ejector to the first and second expansion devices. The first heat absorbing heat exchanger provides cooling at a first temperature and refrigerant fluid from the outlet of the first heat absorbing heat exchanger is directed to a low pressure inlet of the ejector. The second heat absorbing heat exchanger provides cooling at a second temperature and refrigerant fluid from the outlet of the second heat absorbing heat exchanger is directed to the inlet of the compression device.

An apparatus includes a captured carbon dioxide input. The captured carbon dioxide input is coupled to receive captured carbon dioxide from a direct air capture system. The apparatus uses the captured carbon dioxide as a low global warming refrigerant to provide cooling functionality in automotive, commercial, and industrial applications, or other operations involving low global warming refrigerants. In various embodiments, the apparatus is a refrigeration apparatus or a heat pump apparatus. Low global warming carbon dioxide refrigerant is natural, non-toxic, non-flammable, and abundant when obtained from a direct air capture system. Moreover, carbon dioxide refrigerant has a high heat transfer coefficient and has a global warming potential (GWP) of one. Carbon dioxide refrigerant is a more sustainable and efficient coolant option than common refrigerants, such as R22, R152, R404a, and R1234yf refrigerants.

An ejector-based cryogenic refrigeration system for cold energy recovery includes a first cryogenic refrigeration loop connected by a helium compressor and a cryogenic refrigerator and a second cryogenic refrigeration loop connected by the helium compressor, a regenerator, an ejector, a cold head of the cryogenic refrigerator, an end to be cooled and a pressure regulating valve. The cryogenic refrigerator is separated from the end to be cooled. The cryogenic refrigerator and the cryogenic helium cooling loop share a helium compressor, which improves the utilization efficiency of the device and reduces the cost. The ejector allows a part of fluids to circulate in the cryogenic loop, so as to maintain a required cryogenic condition, recover the pressure of the fluids, reduce the gas flowing though the compressor loop, and thus reduce the power consumption of the compressor.

A method for controlling a vapour compression system (1) is disclosed, the vapour compression system (1) comprising at least one expansion device (8) and at least one evaporator (9). For each expansion device (8), an opening degree of the expansion device (8) is obtained, and a representative opening degree, OD.sub.rep, is identified based on the obtained opening degree(s) of the expansion device(s) (8). The representative opening degree could be a maximum opening degree, OD.sub.max, being the largest among the obtained opening degrees. The representative opening degree, OD.sub.rep, is compared to a predefined target opening degree, OD.sub.target, and a minimum setpoint value, SP.sub.rec, for a pressure prevailing inside a receiver (7), is calculated or adjusted, based on the comparison. The vapour compression system (1) is controlled to obtain a pressure inside the receiver (7) which is equal to or higher than the calculated or adjusted minimum setpoint value, SP.sub.rec.

A method for controlling a vapour compression system (1) is disclosed, the vapour compression system (1) comprising at least one expansion device (8) and at least one evaporator (9). For each expansion device (8), an opening degree of the expansion device (8) is obtained, and a representative opening degree, OD.sub.rep, is identified based on the obtained opening degree(s) of the expansion device(s) (8). The representative opening degree could be a maximum opening degree, OD.sub.max, being the largest among the obtained opening degrees. The representative opening degree, OD.sub.rep, is compared to a predefined target opening degree, OD.sub.target, and a minimum setpoint value, SP.sub.rec, for a pressure prevailing inside a receiver (7), is calculated or adjusted, based on the comparison. The vapour compression system (1) is controlled to obtain a pressure inside the receiver (7) which is equal to or higher than the calculated or adjusted minimum setpoint value, SP.sub.rec.

Disclosed is a refrigeration system having: a steam ejector with an ejector outlet; and a passive flow trap connected to the ejector outlet.

Disclosed is a refrigeration system having: a steam ejector with an ejector outlet; and a passive flow trap connected to the ejector outlet.

An ejector and a refrigeration system. The ejector includes: a high-pressure fluid passage, a flow valve for controlling a flow rate in the high-pressure fluid passage; a suction fluid passage; a mixing chamber, which includes a mixed fluid outlet; a thermal bulb disposed upstream of the flow valve, in the high-pressure fluid passage or outside the high-pressure fluid passage; and an elastic diaphragm disposed in the high-pressure fluid passage, wherein a closed cavity is on a first side of the diaphragm, and the high-pressure fluid passage is on a second side of the diaphragm; the thermal bulb in communication with the closed cavity, and the thermal bulb and the closed cavity are filled with fluid; and the diaphragm is associated with the flow valve so that an opening degree of the flow valve varies in response to a change in a pressure difference across two sides of the diaphragm.

An ejector and a refrigeration system. The ejector includes: a high-pressure fluid passage, a flow valve for controlling a flow rate in the high-pressure fluid passage; a suction fluid passage; a mixing chamber, which includes a mixed fluid outlet; a thermal bulb disposed upstream of the flow valve, in the high-pressure fluid passage or outside the high-pressure fluid passage; and an elastic diaphragm disposed in the high-pressure fluid passage, wherein a closed cavity is on a first side of the diaphragm, and the high-pressure fluid passage is on a second side of the diaphragm; the thermal bulb in communication with the closed cavity, and the thermal bulb and the closed cavity are filled with fluid; and the diaphragm is associated with the flow valve so that an opening degree of the flow valve varies in response to a change in a pressure difference across two sides of the diaphragm.