A method for controlling ejector capacity in a vapour compression system (1) is disclosed. A parameter value being representative for a flow rate of liquid refrigerant from the evaporator(s) (8, 10) and into a return pipe (12, 13) is obtained, and the capacity of the ejector(s) (6) is adjusted based on the obtained parameter value. Ejector capacity may be shifted between low pressure ejectors (liquid ejectors) (6a, 6b, 6c, 6d) and high pressure ejectors (gas ejectors) (6e, 6f).

An air conditioning system, which includes an indoor heat exchanger, an outdoor heat exchanger, a compressor, a throttling device, a four-way valve and an ejection device; the indoor heat exchanger, the outdoor heat exchanger, the compressor and the throttling device form a closed-loop refrigerant circulation circuit, the four-way valve is configured to switch the air conditioning system between a cooling mode and a heating mode, and the ejection device is configured to be capable of being connected to a discharge side of the compressor when the air conditioning system executes the heating mode, so as to improve a heating effect of the air conditioning system. This system has a lower cost and a simple structure for easier maintenance, and the energy efficiency ratio is improved, so that the heating effect of the air conditioning system can be improved when the air conditioning system executes the heating mode.

A temperature chamber for conditioning air includes a temperature-insulated space which receives test material, and a temperature control device for controlling the temperature of the test space. The temperature control device allows a temperature in a range of −50° C. to +180° C. to be established within the space, and has a cooling device including a cooling circuit with a refrigerant, a heat exchanger, a compressor, a condenser, and an expansion element. A jet device is connected to a low-pressure side of the cooling circuit downstream of the heat exchanger and upstream of the compressor, a first bypass is connected to a high-pressure side of the cooling circuit downstream of the compressor, and the refrigerant is suppliable to the jet device from the high-pressure side via the first bypass as a driving fluid.

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.

An air conditioner includes an ejector that raises a pressure of refrigerant by using energy for refrigerant decompression and expansion. A switching mechanism switches between a refrigerant flow in a first operation and a refrigerant flow in a second operation. The air conditioner is configured such that in the first operation, refrigerant compressed by a compression mechanism radiates heat in a use-side heat exchanger and is decompressed and expanded by the ejector while refrigerant evaporated in a heat-source-side heat exchanger is raised in pressure by the ejector. The air conditioner is configured such that in the second operation, refrigerant compressed by the compression mechanism radiates heat in the heat-source-side heat exchanger and is decompressed and expanded by a first expansion valve before being evaporated in the use-side heat exchanger while refrigerant does not flow through the ejector.

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.

A method for controlling ejector capacity in a vapour compression system (1) is disclosed. A parameter value being representative for a flow rate of liquid refrigerant from the evaporator(s) (8, 10) and into a return pipe (12, 13) is obtained, and the capacity of the ejector(s) (6) is adjusted based on the obtained parameter value. Ejector capacity may be shifted between low pressure ejectors (liquid ejectors) (6a, 6b, 6c, 6d) and high pressure ejectors (gas ejectors) (6e, 6f).

An air conditioning system, which includes an indoor heat exchanger, an outdoor heat exchanger, a compressor, a throttling device, a four-way valve and an ejection device; the indoor heat exchanger, the outdoor heat exchanger, the compressor and the throttling device form a closed-loop refrigerant circulation circuit, the four-way valve is configured to switch the air conditioning system between a cooling mode and a heating mode, and the ejection device is configured to be capable of being connected to a discharge side of the compressor when the air conditioning system executes the heating mode, so as to improve a heating effect of the air conditioning system. This system has a lower cost and a simple structure for easier maintenance, and the energy efficiency ratio is improved, so that the heating effect of the air conditioning system can be improved when the air conditioning system executes the heating mode.

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.

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.