The present invention relates to an integrated air-conditioning (A/C) circuit for a Carbon Dioxide (CO2) refrigeration system having a CO2 based refrigerant circuit including a high pressure refrigerant cooling heat exchanger that passes refrigerant received at a high pressure in heat exchange relationship with a cooling medium. The A/C circuit is nested within the CO2 refrigeration system and includes a means of directing discharge from an outlet line of the refrigerant cooling heat exchanger into the nested air-conditioning circuit. The A/C circuit further includes a means of reducing the pressure of the refrigerant directed from the outlet line of the refrigerant cooling heat exchanger, and a refrigerant heating heat exchanger for receiving the refrigerant having a reduced pressure and passing the refrigerant in heat exchange relationship with a heating medium to generate chilled fluid.

A system for controlling a plurality of ejectors in an ejector refrigeration circuit includes the plurality of ejectors and a controller. Each of the plurality of ejectors include a primary high pressure input port, a secondary low pressure input port, and an output port. The controller is coupled to each of the plurality of ejectors and adapted to generate a plurality of maps based on a set of predefined conditions. Each of the plurality of maps is associated with a corresponding temperature of a heat rejecting heat exchanger. The controller identifies a first map from the plurality of maps associated with a first temperature of the heat rejecting heat exchanger and an input signal from a first ejector indicative of a flow rate of a refrigerant fluid through the first ejector. Finally, the controller adjusts opening percentages of the plurality of ejectors based on the identified first map.

An ejector includes a body having a nozzle passage that depressurizes a refrigerant flowing out of a swirling space in which the refrigerant is swirled, a suction passage that draws a refrigerant from an external, and a diffuser passage that mixes an ejection refrigerant jetted from the nozzle passage and a suction refrigerant drawn from the suction passage together and pressurizes the mixed refrigerant. The body also has a gas-liquid separation space that separates the refrigerant flowing out of the diffuser passage into gas and liquid by an action of a centrifugal force, and multiple liquid-phase refrigerant outflow passages through which the liquid-phase refrigerant separated by the gas-liquid separation space flows out to the multiple evaporators.

An ejector using a swirl flow includes an ejector body comprising a main inlet into which a main flow in high pressure flows, a nozzle section in fluid communication with the main inlet, a mixing portion in fluid communication with the nozzle section, a diffuser in fluid communication with the mixing portion, and a discharge portion in fluid communication with the diffuser; and a suction pipe inserted in a center of the ejector body, the suction pipe including a through-hole into which a suction flow in low pressure flows, and a leading end portion an outer surface of which forms a plurality of inclined passages with the nozzle section of the ejector body, the plurality of inclined passages allowing the main flow to be moved to the mixing portion so as to form a swirl flow, wherein the main flow entering through the main inlet of the ejector body and the suction flow entering through the through-hole of the suction pipe are swirled and mixed in the mixing portion of the ejector body, and then are discharged outside through the diffuser and the discharge portion.

A body of an ejector includes a diffuser passage, in which an ejection refrigerant jetted from a nozzle passage and a suction refrigerant drawn from a suction passage are mixed together and pressurized by arranging a passage formation member, and a gas-liquid separation space, in which the refrigerant flowing out of the diffuser passage is separated into gas and liquid by the action of a centrifugal force. An inlet part of an oil return passage that is open in the gas-liquid separation space is arranged at a position closer to an outer peripheral side than to an axis center of the passage formation member.

An internal heat exchanger and a first flow control valve are connected in series between a condenser and a refrigerant inlet of an ejector. A gas refrigerant outlet of a gas-liquid separator is connected to a suction port of a compressor. A first bypass circuit connects a refrigerant outlet of the condenser to an intermediate pressure portion of the compressor via a second flow control valve and the internal heat exchanger. A second bypass circuit connects a refrigerant outlet of the internal heat exchanger to the liquid refrigerant outlet of the gas-liquid separator via a third flow control valve. While the second flow control valve is opened such that the refrigerant flows through the first bypass circuit, the fourth flow control valve is switched to be opened or closed, and the third flow control valve is switched to be closed or opened.

A method for controlling a vapour compression system (1) is disclosed. The vapour compression system (1) includes an ejector (4), and has a non-return valve (11) arranged in the refrigerant path between an outlet (12) of an evaporator (7) and an inlet (10) of a compressor unit (2), in such a manner that a refrigerant flow from the outlet (12) of the evaporator (7) towards the inlet (10) of the compressor unit (2) is allowed, while a fluid flow from the inlet (10) of the compressor unit (2) towards the outlet (12) of the evaporator (7) is prevented. A pressure, P.sub.0, of refrigerant leaving the evaporator (7) is measured and a value being representative for a pressure, P.sub.suc, of refrigerant entering the compressor unit (2) is obtained. The pressures, P.sub.0 and P.sub.suc, are compared to respective reference pressure values, P.sub.0,ref and P.sub.suc,ref. In the case that .sub.0>.sub.suc, where .sub.0=P.sub.0P.sub.0,ref and .sub.suc=P.sub.sucP.sub.suc,ref, the compressor unit (2) is controlled based on P.sub.0, and in the case that .sub.suc>.sub.0, the compressor unit (2) is controlled based on P.sub.suc.

A system for detection and correction of reverse flow in an ejector refrigeration circuit, includes ejectors, first sensors for measuring an ejector suction superheat of a refrigerant at a secondary low pressure input port of each of the ejectors, and a second sensor for measuring a superheat of the refrigerant upstream relative to the secondary low pressure input port. A controller receives the ejector suction superheats and the refrigerant superheat and determines whether a superheat difference between each of the ejector suction superheats and the refrigerant superheat falls below a threshold superheat difference. The controller identifies a first ejector as a reverse flow affected ejector based on the determined superheat difference. The controller compares opening percentages of the ejectors to determine a second ejector having the largest opening percentage and controls the first ejector and the second ejector to increase a refrigerant flow rate of the first ejector.

An ejector mixer has a convergent section and a downstream divergent section downstream of the convergent section. The downstream divergent section has a divergence half angle of 0.1-2.0 over a first span of at least 3.0 times a minimum diameter of the mixer.

Systems and methods for natural gas liquefaction capacity augmentation using supplemental cooling systems and methods to improve the efficiency of a liquefaction cycle for producing liquefied natural gas (LNG).