An ejector refrigeration circuit (1), which is configured for circulating a refrigerant, in particular carbon dioxide, comprises at least two controllable ejectors (6, 7), which are connected in parallel and respectively comprise a primary high pressure input port (6a, 7a), a secondary low pressure input port (6b, 7b) and an output port (6c, 7c); and a control unit (28), which is configured for operating the ejector refrigeration circuit (1) employing a method which comprises the steps of: a) operating a first ejector (6) of the at least two controllable ejectors (6, 7) by controlling the opening of its high pressure port (6a) until the maximum efficiency of said first ejector (6) has been reached or the actual refrigeration demands are met; b) operating at least one additional ejector (7) of the at least two controllable ejectors (6, 7) by opening its primary high pressure input port (7a) for increasing the refrigeration capacity of the ejector refrigeration circuit (1) in case the actual refrigeration demands are not met by operating the first ejector (6) alone.

An ejector and a refrigeration cycle apparatus having an ejector are provided. The ejector may include an ejector body having an accommodation space therein, a suction portion through which a high pressure refrigerant and a low pressure refrigerant may be suctioned into the accommodation space, and a mixing portion configured to mix the high pressure refrigerant with the low pressure refrigerant; a nozzle provided in the ejector body, having a nozzle neck and an expansion portion, and configured to inject the high pressure refrigerant into the mixing portion; a first needle moveably provided at the expansion portion, and configured to control a flow sectional area of the expansion portion; a second needle moveably provided at the nozzle neck, and configured to control a flow sectional area of the nozzle neck; a first needle drive configured to drive the first needle; and a second needle drive configured to drive the second needle. With such a configuration, the flow sectional area of the nozzle neck and the flow sectional area of the expansion portion may be independently controlled in correspondence to a drive condition.

An ejector comprises: a housing having a first chamber and a second chamber, the first chamber having a first inlet for introducing high-pressure fluid and a second inlet for introducing low-pressure fluid, and the second chamber is sequentially provided with a reducing section, a mixing section, and an expanding section along the direction of fluid movement; a nozzle installed in the first chamber of the housing and is only capable of moving along the axis direction of the first chamber of the housing; a magnetic rotating mechanism, comprising an outer ring and an inner ring, the inner ring is rotatably connected to the second end of the nozzle.

An ejector includes a nozzle, a body including a refrigerant suction port and a pressure increasing portion, a passage forming member inserted into the nozzle, and an actuation device moving the passage forming member. A nozzle passage includes a smallest passage cross-sectional area portion, a convergent portion, and a divergent portion. The passage forming member includes a tip portion which changes the passage cross-sectional area at the smallest passage cross-sectional area portion when the actuation device moves the passage forming member. A positive displacement amount is defined as an amount of a displacement of the passage forming member when the passage forming member is moved so as to increase the passage cross-sectional area at the smallest passage cross-sectional area portion. The tip portion has a shape in which an increase rate of the smallest passage cross-sectional area portion is increased according to an increase of the positive displacement amount.

A packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing. A compressor, an interior coil, an exterior coil and a reversing valve are positioned within the casing. The reversing valve is configured for selectively reversing a flow direction of compressed refrigerant from the compressor. The packaged terminal air conditioner also includes at least one phase separator and at least one ejector.

An ejector refrigeration circuit comprises: a high pressure ejector circuit comprising in the direction of flow of a circulating refrigerant: a heat rejecting heat exchanger/gas cooler having an inlet side and an outlet side; at least one ejector comprising a primary high pressure input port, a secondary low pressure input port, and an output port, the primary high pressure input port being fluidly connected to the outlet side of the heat rejecting heat exchanger/gas cooler; a receiver, having a liquid outlet, a gas outlet and an inlet, which is fluidly connected to the output port of the at least one ejector; at least one compressor having an inlet side and an outlet side, the inlet side of the at least one compressor being fluidly connected to gas outlet of the receiver.

In an ejector, a passage formation member is disposed inside a body forming a space therein. Provided between an inner peripheral surface of the body and the passage formation member are a nozzle passage functioning as a nozzle, a mixing passage in which an ejection refrigerant ejected from the nozzle passage and a suction refrigerant drawn through a suction passage are mixed together, and a diffuser passage that converts a kinetic energy of the refrigerant that has flowed out of the mixing passage into a pressure energy. The mixing passage has a shape gradually reducing in cross-sectional area toward a downstream side in the refrigerant flow.

The present application provides a carbon dioxide based refrigeration system. The carbon dioxide based refrigeration system may include a mid temperature cycle with a mid temperature ejector, a low temperature cycle with a low temperature ejector, and a gas cooler/condenser in communication with the mid temperature cycle and the low temperature cycle.

An ejector has a nozzle, a body, a passage defining member and a drive portion. The body has a refrigerant suction port and a pressure increasing portion. A nozzle passage is defined between an inner surface of the nozzle and an outer surface of the passage defining member and has a minimum sectional area portion, a tapered portion, and an expansion portion. The minimum sectional area portion has a smallest passage sectional area. The tapered portion is located upstream of the minimum sectional area portion in a refrigerant flow direction and has a passage sectional area decreasing toward the minimum sectional area portion gradually. The expansion portion is located downstream of the minimum sectional area portion in the refrigerant flow direction and has a passage sectional area increasing gradually. The passage defining member has a groove that is recessed to increase the passage sectional area of the nozzle passage.

An ejector has a swirling space, a pressure reducing space, a suction passage, a pressure increasing space, a nozzle passage, a diffuser passage, a passage forming member that forms the nozzle passage and the diffuser passage, and a vibration suppressing portion that suppresses a vibration of the passage forming member. The vibration suppressing portion has (i) a first elastic member that applies a load to the passage forming member in a direction in which an area of a cross section perpendicular to the direction of the central axis of the nozzle passage and the diffuser passage decreases and (ii) a second elastic member that applies a load to the passage forming member in a direction opposite from the direction in which the first elastic member applies the load to the passage forming member.