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).

A CO.sub.2 based system, such as a heat pump system or a refrigeration system, is disclosed. The system comprises a plurality of ejectors arranged in parallel. Each of the ejectors comprises a motive port and a suction port. Each of the ejectors has a fixed geometry. A first actuated ball valve is arranged in front of the motive port. A second actuated ball valve is arranged in front of the suction port. The system comprises a control unit arranged and configured to control the activity of the ball valves on the basis of one or more predefined criteria.

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 refrigeration circuit includes a compressor, a heating heat exchanger, a first decompressor, an exterior heat exchanger, a second decompressor, a cooling heat exchanger, a heating ejector, a heating-side gas-liquid separator, and a refrigerant circuit switch. The refrigerant circuit switch switches between a refrigerant circuit in a first dehumidifying-heating mode and a refrigerant circuit in a second dehumidifying-heating mode. A flow direction of the refrigerant through the exterior heat exchanger in the first dehumidifying-heating mode is the same as a flow direction of the refrigerant through the exterior heat exchanger in the second dehumidifying-heating mode. The flow direction of the refrigerant through the exterior heat exchanger in the first dehumidifying-heating mode is different from a flow direction of the refrigerant through the exterior heat exchanger in the heating mode.

A system (20; 300) comprises: a compressor (22) having a suction port (40) and a discharge port (42); an ejector (32) having a motive flow inlet (50), a suction flow inlet (52), and an outlet (54); a separator (34) having an inlet (72), a vapor outlet (74), and a liquid outlet (76); a first heat exchanger (24); an expansion device (28); and a second heat exchanger (26; 302). Conduits and valves are positioned to provide alternative operation in: a cooling mode; a first heating mode; and a second heating mode. In the cooling mode and second heating mode, a needle (60) of the ejector is closed.

The present disclosure relates to an air conditioning device having a plurality of ejectors, the air conditioning device comprising a plurality of ejectors which have a refrigerant circuit comprising a compressor, a condenser and an evaporator, are connected in parallel to the refrigerant circuit, and are formed so as to each have a different maximum refrigerant flow, and a control unit which, according to a driving condition of the air conditioning device, controls so that the refrigerant flows to one ejector among the plurality of ejectors, and the refrigerant does not flow to the rest of the ejectors.

A vapour compression system (1) comprising at least two evaporator groups (5a, 5b, 5c), each evaporator group (5a, 5b, 5c) comprising an ejector unit (7a, 7b, 7c), at least one evaporator (9a, 9b, 9c) and a flow control device (8a, 8b, 8c) controlling a flow of refrigerant to the at least one evaporator (9a, 9b, 9c). For each evaporator group (5a, 5b, 5c) the outlet of the evaporator (9a, 9b, 9c) is connected to a secondary inlet (12a, 12b, 12c) of the corresponding ejector unit (7a, 7b, 7c). The vapour compression system (1) can be controlled in an energy efficient and stable manner. A method for controlling the vapour compression system (1) is also disclosed.

An ejector-type refrigeration cycle includes a radiator radiating heat of refrigerant discharged from a compressor, an ejector depressurizing the refrigerant cooled in the radiator, a gas-liquid separator separating gas and liquid of the refrigerant flowing out of a diffuser portion of the ejector, an evaporator disposed in a refrigerant passage connecting the gas-liquid separator and a refrigerant suction port of the ejector, and an opening-closing valve switching between a first refrigerant flow path, in which an ejection refrigerant ejected from a nozzle portion of the ejector flows out of the diffuser portion, and a second refrigerant flow path, in which the ejection refrigerant flows out of the refrigerant suction port. When a rotation rate of the compressor is lower than or equal to a standard rotation rate, the first refrigerant flow path is switched to the second refrigerant flow path.

A swirl space forming member that forms a swirl space in which a refrigerant flowing into a nozzle portion of an ejector swirls around an axis of the nozzle portion. In this way, even when the refrigerant flowing out of a first evaporator is a gas-phase refrigerant, pressure of the refrigerant on a swirling center axis side in the swirl space is reduced to be able to start condensation by swirling the refrigerant, and a gas-liquid two-phase refrigerant in which a condensation nucleus is generated can flow into the nozzle portion. Thus, occurrence of a condensation delay in the refrigerant in the nozzle portion can be restricted.

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.