A method for controlling a vapour compression system (1) is disclosed. The vapour compression system (1) comprises an ejector (6) and a liquid separating device (10) arranged in a suction line. At least one evaporator (9) is allowed to be operated in a flooded state. A flow rate of refrigerant from the liquid separating device (10) to the secondary inlet (15) of the ejector (6) is detected, and it is determined whether or not the flow rate is sufficient to remove liquid refrigerant produced by the evaporator(s) (9) being allowed to be operated in a flooded state from the liquid separating device (10). In the case that it is determined that the flow rate of refrigerant from the liquid separating device (10) to the secondary inlet (15) of the ejector (6) is insufficient to remove liquid refrigerant produced by the evaporator(s) (9), the flow rate of refrigerant from the liquid separating device (10) to the secondary inlet (15) of the ejector (6) is increased, and/or a flow rate of liquid refrigerant from the evaporator(s) (9) to the liquid separating device (10) is decreased.

A method for operating a compressor unit (2) comprising one or more compressors (8, 9, 10) is disclosed, the compressor unit (2) being arranged in a vapour compression system (1). Two or more options for distributing the available compressor capacity of the compressor unit (2) between being connected to a high pressure suction line (11) and to a medium pressure suction line (13) are defined. For each option, an expected impact on one or more operating parameters of the vapour compression system (1), resulting from distributing the available compressor capacity according to the option, is predicted. An option is selected, based on the predicted expected impact for the options, and based on current operating demands of the vapour compression system (1), and the available compressor capacity is distributed according to the selected option, e.g. by means of settings of one or more valve arrangements (14, 15).

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 ejector for combining a stream of refrigerant from a primary loop with a stream of refrigerant from an auxiliary cooling loop, thereby improving system efficiency.

An ejector has an interior nozzle, an exterior nozzle, a suction part, a mixing part and a diffuser part. The interior nozzle and the exterior nozzle are arranged coaxially with each other. A driving fluid is supplied to the interior nozzle and/or the exterior nozzle. The suction part is arranged on an outer periphery of the exterior nozzle and sucks a suction fluid by a driving fluid jet ejected from the interior nozzle and/or the exterior nozzle. A mixing part mixes the driving fluid jet with the suction fluid, and supplies a mixture fluid. The diffuser part reduces a flow speed of the mixture fluid and ejects the mixture fluid outside. An outlet part of the interior nozzle is arranged at an upstream side of the ejector more than an outlet part of the exterior nozzle along the axial direction of the ejector.

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) comprising an ejector (6) is disclosed. In the case that a pressure difference between a pressure prevailing in the receiver (7) and a pressure of refrigerant leaving the evaporator (9) decreases below a first lower threshold value, the pressure of refrigerant leaving the heat rejecting heat exchanger (5) is kept at a level which is slightly higher than the pressure level providing optimal COP. Thereby the ejector (6) can operate at lower ambient temperatures, and the energy efficiency of the vapour compression system (1) is improved.

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 method for controlling a vapour compression system (1) is disclosed. Malfunctioning of a gas bypass valve (8) is registered. An actual opening degree of the gas bypass valve (8) is derived, and a target opening degree of the gas bypass valve (8) is derived, based on one or more control parameters of the vapour compression system (1). The actual opening degree is compared to the target opening degree, and the vapour compression system (1) is controlled based on the comparison, and in order to match a mass flow of gaseous refrigerant through the gas bypass valve (8) to the actual opening degree of the gas bypass valve (8).

A system includes a pressure exchanger (PX) configured to receive a first fluid at a first pressure and a second fluid at a second pressure and exchange pressure between the first fluid and the second fluid. The system further includes a condenser configured to provide corresponding thermal energy from the first fluid to a corresponding environment. The system further includes a first ejector to receive a first gas and increase pressure of the first gas to form the second fluid at the second pressure. The first ejector is further to provide the second fluid at the second pressure to the PX.

An ejector includes a body part having a depressurizing space in which a refrigerant flowing out of a swirling space is depressurized, a suction passage that draws a refrigerant from an external, and a pressurizing space in which the refrigerant from the depressurizing space is mixed with the refrigerant from the suction passage, a conical passage formation member that is arranged in the body part, and a driving device that displaces a nozzle body of the body part forming the depressurizing space. A nozzle passage is defined on an outer peripheral side of the passage formation member in the depressurizing space, a diffuser passage is formed on an outer peripheral side of the passage formation member in the pressurizing space, and an actuating bar that couples the driving device with the nozzle body is arranged without crossing the diffuser passage.