A heat-driven refrigeration/heat-pump system comprises at least one vapor expansion stage and at least one vapor compression stage, a condenser, and an evaporator, while the power consumption of the compression stages is fully supplied by the power output of the expansion stages. In the system, a vapor absorber/generator unit is adopted, such that at least one expansion stage is fed by the vapor from the generator, and at least one power stage; compression or expansion, delivers its output stream to the absorber instead of to the condenser. In the new arrangement the expansion stages produce surplus power, facilitating a supplementary refrigeration loop between the evaporator and the condenser to which there is no direct expense of heat from the generator, thereby improving the overall performance of the system.

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. A liquid level sensor (18) is arranged in the liquid separating device (10). A liquid level in the liquid separating device (10) is monitored by means of the liquid level sensor (18). In the case that the liquid level in the liquid separating device (10) is above a predefined threshold level, a control parameter of the vapour compression system (1) is adjusted in order to increase a flow rate of refrigerant from the liquid separating device (10) to the secondary inlet (15) of the ejector (6) and/or decrease a flow rate of liquid refrigerant from the evaporator(s) (9) to the liquid separating device (10).

A refrigerant that has flowed out of a liquid ejector radiates heat in a radiator, and a liquid-phase refrigerant that has radiated heat in the radiator flows into an ejection refrigerant passage of the liquid ejector. A discharged refrigerant of a compressor that suctions the refrigerant that has flowed out of a low-pressure evaporator flows into an inflow refrigerant passage of the liquid ejector. An ejector adopted as the liquid ejector is one in which an ejection refrigerant is ejected from the ejection refrigerant passage to a gas-liquid mixing portion, and the ejection refrigerant is ejected on an outer circumferential side of the inflow refrigerant flowing from the inflow refrigerant passage into the gas-liquid mixing portion.

A method for controlling a variable capacity ejector unit (7) arranged in a refrigeration system (1) is disclosed. An ejector control signal for the ejector unit (7) is generated, based on an obtained temperature and an obtained pressure of refrigerant leaving a heat rejecting heat exchanger (3), or on the basis of a high pressure valve control signal for controlling an opening degree of a high pressure valve (6) arranged fluidly in parallel with the ejector unit (7). The ejector control signal indicates whether the capacity of the ejector unit (7) should be increased, decreased or maintained. The capacity of the ejector unit (7) is controlled in accordance with the generated ejector control signal. The power consumption of the refrigeration system (1) is reduced, while the pressure of the refrigerant leaving the heat rejecting heat exchanger (3) is maintained at an acceptable level.

As an ejector of the present disclosure and a cooling apparatus having the same include a suction guide unit at least partially having a curved surface so that the ejector guides a flow of a refrigerant, a structure is improved and thus a flow loss can be reduced. Also, through the improved structure, a mixture rate between a refrigerant passing through a nozzle unit and a refrigerant passing through a suction unit is improved, so that pressure rising efficiency can be increased to reduce a compressor load, and thus energy efficiency can be increased due to an increase in efficiency of the ejector.

A valve (9) for use in a vapour compression system (1) is disclosed. The valve (9) comprises a first inlet (13) arranged to be connected to a gaseous outlet (11) of a receiver (6), a second inlet (14) arranged to be connected to an outlet of an evaporator (8), a first outlet (15) arranged to be connected to an inlet of a compressor unit (2), a non-return valve arrangement (19) arranged to allow a fluid flow from the second inlet (14) towards the first outlet (15), but to prevent a fluid flow from the first outlet (15) towards the second inlet (14), and a control valve mechanism (20) arranged to control a fluid flow from the first inlet (13) towards the first outlet (15).

A method for controlling a vapor compression system (1) is disclosed, the vapor compression system (1) comprising an ejector (5). The method comprises controlling a compressor unit (2) in order to adjust a pressure inside a receiver (6), on the basis of a detected pressure of refrigerant leaving an evaporator (8). The portion of refrigerant leaving the evaporator (8) which is supplied to a secondary inlet (15) of the ejector is maximized and the portion of refrigerant supplied directly to the compressor unit (2) is minimized, while ensuring that the pressure of refrigerant leaving the evaporator (8) does not decrease below an acceptable level.

A cooling system for a motor to power a compressor in a vapor compression system is provided. The cooling system includes a housing with a cavity enclosing the motor and defining a central axis and fluid directing features extending into the cavity and oriented parallel to the central axis. The cooling system further includes a fluid circuit configured to circulate a cooling fluid between the housing and the motor. The fluid circuit includes a first cooling fluid path defined by directing features that cause a first portion of cooling fluid to travel around a first portion of the motor and a second cooling fluid path defined by fluid directing features that cause a second portion of cooling fluid to travel around a second portion of the motor. The second portion of the motor is located opposite the first portion.

In an ejector-type refrigeration cycle device provided with a first compression mechanism and a second compression mechanism, a refrigerant outlet of a suction side evaporator is coupled to a refrigerant suction port of the ejector, and a second compression mechanism is provided between the suction side evaporator and the refrigerant suction port of the ejector. Thus, even in an operation condition in which suction capacity of the ejector is decreased in accordance with a decrease of the flow amount of a drive flow of the ejector, the suction capacity of the ejector can be supplemented by the operation of the second compression mechanism. Accordingly, even when a variation in the flow amount of the drive flow is caused, the ejector-type refrigeration cycle device can be stably operated.

When an ejector having a variable nozzle and a variable throttle mechanism are integrated together as an ejector module, a nozzle-side central axis CL1 and a decompression-side driving mechanism have a twisted positional relationship, if the nozzle-side central axis CL1 is defined as a central axis of a nozzle-side driving mechanism in a displacement direction in which the nozzle-side driving mechanism of the ejector having the variable nozzle displaces a needle valve, and the decompression-side central axis CL2 is defined as a central axis of a decompression-side driving mechanism in a displacement direction in which the decompression-side driving mechanism of the variable throttle mechanism displaces a throttle valve. When viewed from the central axis direction of one of the nozzle-side central axis CL1 and the decompression-side central axis CL2, a driving portion corresponding to the one central axis is disposed to overlap with the other central axis.