Jet pump unit and refrigerant circuit

Abstract

The invention relates to a jet pump unit (300) having at least two jet pumps (100), which are connected in parallel with one another, for conveying a suction fluid (242) in a refrigerant circuit (200) of a temperature-control system by means of a propellant fluid (231) using the Bernoulli effect, wherein each of the at least two jet pumps has a primary nozzle (103) for accelerating the propellant fluid, a secondary connection interface (102) for supplying the suction fluid, a mixing tube (104) downstream of the primary nozzle (103) and downstream of the secondary connection interface (102), and a diffuser (105) downstream of the mixing tube (104); and the jet pump unit has a common pressure line (310) for supplying the propellant fluid to the jet pumps (100) connected in parallel and a common actuating mechanism (320, 320A, 420, 420B, 520, 520A, 520B, 520C, 520D) for selectively opening and closing the common pressure line (310) for individual jet pumps (100), a plurality of jet pumps, or all of the jet pumps connected in parallel. The invention further relates to a refrigerant circuit (200) comprising at least one such jet pump unit (300).

Description

[0001] R.415443-IP2

[0002] - 1 -

[0003] Description

[0004] title

[0005] Jet pump unit and refrigerant circuit

[0006] The present invention relates to a jet pump unit with several jet pumps connected in parallel to each other for pumping a suction fluid in a refrigerant circuit of a temperature control system and to a refrigerant circuit with such a jet pump unit.

[0007] Background of the invention

[0008] Jet pumps (also known as ejectors) can be used, for example, in refrigeration circuits of temperature control systems (e.g., for temperature control of one or more vehicle components). An ejector has a primary flow and a secondary flow that mix within the ejector. The primary flow is forced through a nozzle at high pressure and exits at high velocity and therefore low pressure. The secondary flow starts at a significantly lower pressure than the primary flow but is also accelerated in a nozzle. The two flows mix, and the secondary flow is accelerated because the primary flow exits the nozzle at very high velocity and carries the secondary flow along with it (momentum is transferred from the primary to the secondary flow).In the case of a supersonic ejector, a compression pulse occurs at the end of the mixing tube, causing the pressure to rise again. In a subsequent diffuser, additional kinetic energy can be converted into pressure. In summary, the expansion of a high-pressure flow (primary flow) in an ejector can draw in a secondary flow at a lower pressure. With a correct design, the pressure after exiting the ejector is higher than at the secondary inlet. R.415443-IP2.

[0009] - 2 -

[0010] Disclosure of the invention

[0011] According to the invention, a jet pump unit and a refrigerant circuit with the features of the independent claims are proposed. Advantageous embodiments are the subject of the dependent claims and the following description.

[0012] A jet pump usable within the framework of the jet pump unit according to the invention for pumping a suction fluid in a refrigerant circuit of a temperature control system using a motive fluid and utilizing the Bernoulli effect, has a primary nozzle for accelerating the motive fluid and a secondary connection interface for supplying the suction fluid, as well as a mixing tube downstream of the primary nozzle and downstream of the secondary connection interface, and a diffuser downstream of the mixing tube. At the outlet of the primary nozzle, when the jet pump is correctly designed, the pressure of the motive fluid is lower than the pressure of the suction fluid at the secondary connection interface, causing the suction fluid to be drawn into the mixing tube. In the mixing tube, the motive fluid is slowed down by collisions with molecules of the suction fluid, so that the pressure increases again.This allows the supersonic flow of the mixing fluid, composed of propellant and suction fluid, to be slowed down so much by the end of the mixing tube that the mixing fluid is transferred into a subsonic velocity range and can be further slowed down and compressed in the diffuser.

[0013] The invention utilizes the method of combining several jet pumps connected in parallel (also referred to as ejectors or injectors, depending on their operating point (primarily evacuating or primarily compressing)) into a jet pump unit and controlling them by means of a common control mechanism. The common control mechanism is designed to selectively activate or deactivate one or more of the jet pumps, so that the delivery capacity of the jet pump unit can be varied as required. The common control mechanism offers significant potential savings in terms of manufacturing and maintenance costs, R.415443-IP2

[0014] - 3 -

[0015] as well as in terms of the complexity of the control system. In contrast to the jet pump unit according to the invention, conventionally, each of the parallel-connected jet pumps could be controlled with separate (e.g., electromechanical) valves. Within the scope of this invention, however, a common control with only a single actuating mechanism (e.g., actuator) is possible. For the actuating mechanism, in addition to active control (e.g., electromechanical actuation), passive control, for example using a thermomechanical element (e.g., thermal wax, bimetal, etc.), can also be used, thereby completely eliminating the control effort.

[0016] In detail, the jet pump unit according to the invention comprises at least two jet pumps connected in parallel. The jet pumps are suitable for pumping a suction fluid in a refrigerant circuit of a temperature control system using a motive fluid and utilizing the Bernoulli effect. Each of the at least two jet pumps has a primary nozzle for accelerating the motive fluid, a secondary connection interface for supplying the suction fluid, a mixing tube downstream of the primary nozzle and downstream of the secondary connection interface, and a diffuser downstream of the mixing tube. The jet pump unit has a common pressure line for supplying the motive fluid to the parallel-connected jet pumps and the aforementioned common actuating mechanism for selectively opening and closing the common pressure line for one or all of the parallel-connected jet pumps. The common actuating mechanism (e.g.,A rotary disc that successively opens and closes several openings (each connected to a connection interface of the parallel-connected jet pumps) enables control with particularly low mechanical and regulatory complexity. Conventionally, each of the parallel-connected jet pumps could be controlled by separate (e.g., electromechanical) valves. In contrast, this invention provides for a common control system with only a single actuating mechanism. For the actuating mechanism, in addition to active control (e.g., electromechanical actuator), passive control is also possible, for example, as described in R.415443-IP2.

[0017] - 4 -

[0018] The use of a thermomechanical element (e.g., thermal wax, bimetal, etc.) eliminates the need for control.

[0019] According to at least one embodiment, the common actuating mechanism can include a rotary disc. In particular, the rotary disc can be housed in a casing with a substantially circular internal geometry and configured to open none, one, or more outlets of the casing depending on the rotary disc's rotational position. This allows jet pumps connected to these outlets (hereinafter also referred to as "openings") to be selectively supplied with the motive fluid or cut off from the supply. For this purpose, the rotary disc can, for example, be equipped with a partition that extends radially on the rotary disc and, together with a fixed wall of the casing that also extends radially inward, projects into the casing, and contacts the rotary disc, defines an angular range through which the motive fluid can flow.The outlets can be arranged circumferentially across the base and / or a lateral surface of the housing. Alternatively, the rotary disc can have recesses that can be aligned with the openings of the housing to establish a fluid connection to the jet pumps to be activated.

[0020] According to at least one embodiment, a common suction line is provided for supplying the suction fluid to the parallel-connected jet pumps, and optionally a common control mechanism, e.g., an actuator, is provided for selectively opening and closing the common suction line for individual or all of the parallel-connected jet pumps. Alternatively or additionally, a common outlet line can be provided for discharging the motive fluid and the suction fluid (i.e., the mixed fluid) from the parallel-connected jet pumps, and optionally a common control mechanism, e.g., an actuator, is provided for selectively opening and closing the common outlet line for individual or all of the parallel-connected jet pumps. Selective activation or deactivation of the secondary interface or the outlet offers the additional advantage of preventing backflow of the mixed fluid to the common suction line through jet pumps that are not currently being supplied with motive fluid. R.415443-IP2

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[0022] This is prevented. The actuating mechanism of the secondary side (i.e., the actuating mechanism that opens and closes the common suction line or the output line) can, in particular, be connected to the common actuating mechanism of the primary side, so that a single control element (e.g., actuator) can take over all actuating tasks.

[0023] Alternatively, a separate check valve can be provided at the end of each diffuser to block backflow. In this design, backflow prevention is achieved using individual check valves installed at the outlet of the jet pump unit (in the medium-pressure channel). These valves can then be mounted together, for example, on a common plate outside the housing of each jet pump or in the respective connection interfaces of the common outlet line. This simplifies installation, reducing production costs and improving accessibility for repairs and maintenance.

[0024] As an alternative to the turntable configuration described above, the turntable can also have a cavity into which at least one recess provided in a base and / or top surface and / or a lateral surface of the turntable opens, wherein the at least one recess is configured to align, depending on the position of the turntable, at least partially with openings in a base or top surface or a lateral surface of a housing that receives the turntable. According to at least one embodiment, the at least one recess is configured to simultaneously release one or more of the openings in the wall of the housing.For example, the recess can have an extension along a circumferential direction of the turntable that exceeds the distance between two adjacent openings of the housing, so that one and the same recess can simultaneously expose none, one, or several of the openings, depending on the relative rotational position of the turntable to the housing. A supply line for the suction fluid or propellant fluid, or a discharge line for the mixing fluid, can be provided via the cavity inside the R.415443-IP2.

[0025] - 6 -

[0026] Turntable operation (e.g. via an axial opening in one of the end faces of the turntable).

[0027] Alternatively, the turntable can also comprise a (flat) solid cylinder, in the base and / or top surface of which at least one recess is provided, the design of which corresponds to the at least one recess described here. In such a case, the at least one recess can, in particular, include a channel for supplying the suction or motive fluid or for discharging the mixing fluid.

[0028] For example, at least one recess or depression can be circular bores that can be aligned with the (e.g., also circular) openings by discrete movements of the rotary table. Further options include recesses or depressions extending circumferentially around the rotary table that can align with several of the openings simultaneously or remain aligned with the respective opening over a larger range of motion, thus enabling continuous movement of the rotary table (e.g., to slowly start up a jet pump and not supply it with motive or suction fluid abruptly).

[0029] According to at least one embodiment, the jet pumps connected in parallel can be arranged within a common plane, leading away from the common pressure line. Within the scope of this invention, jet pumps are said to lie within a plane if the gross flow directions (the line connecting the center of the primary nozzle to the center of the outlet port or diffuser) of the parallel jet pumps form an angle of max. 5° with the common plane. The common plane is considered to be a plane that yields the smallest sum of squared angles for the angles enclosed between the gross flow directions and the plane. In particular, the individual jet pumps can lead radially away from the common pressure line, especially such that the primary nozzles (or first connection interfaces that supply the primary nozzles with the propellant fluid) are located on an inner circle and / or the R.415443-IP2

[0030] - 7 -

[0031] The outlet connections of the jet pumps are located on an outer circular axis. In particular, the inner and outer circular axis can be concentric to each other and / or lie in the common plane just described. Such an arrangement has the advantage, for example, that the common pressure line, which is subject to greater mechanical stress, is spatially more confined compared to an outlet line of the jet pump unit designed for lower pressures.

[0032] According to at least one alternative embodiment, the jet pumps connected in parallel are arranged geometrically parallel to each other within a cylindrical shell. The cylindrical shell need not necessarily be physically present in all embodiments; however, in some embodiments a casing tube may be provided within which the jet pumps are arranged. In this embodiment, jet pumps are described as geometrically parallel if the gross flow directions (the line connecting the center of the primary nozzle to the center of the outlet port or diffuser) of the parallel jet pumps differ by a maximum of...

[0033] deviates by 10° from a mutually parallel alignment and / or if the diameter of the "input circle", i.e., the circle that bounds the shell surface on the side of the primary-side connection interfaces of the jet pumps, deviates by a maximum of 10% from the diameter of the "output circle", i.e., the circle that bounds the shell surface on the side of the diffuser outlets. The jet pump unit according to the invention has a common pressure line for supplying the motive fluid to the jet pumps connected in parallel.

[0034] According to at least one alternative embodiment, the jet pumps connected in parallel are arranged geometrically parallel to each other on a curved line, in particular a line forming the circumference of an oval shape, such as a circle or ellipse. Within the scope of this invention, jet pumps are referred to as geometrically parallel if the gross flow directions (connecting line from the center of the primary nozzle to the center of the outlet port or diffuser) of the parallel jet pumps differ from each other by a maximum of 10° and / or if an R.415443-IP2

[0035] - 8 -

[0036] The largest dimension of the mold on which the primary-side connection interfaces are located deviates by a maximum of 10% from the largest dimension of the mold on which the diffuser outlets are located. As mentioned, the mold on which the primary-side connection interfaces are located can be a circle, in which case the largest dimension is the diameter. In other words, the at least two jet pumps are geometrically parallel to each other, particularly axially along a cylindrical shell or the shell of another oval shape. This results in a substantially cylindrical or oval cavity between the at least two jet pumps, which can, for example, accommodate other components of a temperature control system. This is particularly advantageous for components that are to be thermally insulated from the environment, as the jet pumps can provide such thermal insulation.

[0037] According to at least one embodiment, a liquid phase separator is arranged within the cavity. This allows for optimal use of the installation space, and the liquid phase separator is thermally insulated from the environment by the jet pumps, which has a positive effect on the efficiency of the entire refrigerant circuit.

[0038] According to at least one alternative embodiment, the at least two jet pumps are arranged geometrically parallel to each other and lying in a common plane. This is a particularly easy variant to manufacture, as no complex fixtures or other alignment aids are required.

[0039] According to at least one embodiment, all jet pumps connected in parallel within the jet pump unit (regardless of their relative arrangement) can be identical, which has a positive effect on manufacturing complexity. Alternatively, however, at least one of the at least two jet pumps can differ in its design from the other two. For example, one of the jet pumps can be smaller to allow for finer gradation of the operating intervals. For example, the at least two jet pumps can be provided as tube ejectors. Tube ejectors are conventionally defined as R.415443-IP2.

[0040] - 9 -

[0041] While jet pumps are understood to have flow-shaping components (also referred to as "cores") that are each installed in a separate (individual for each jet pump) pipe section serving as a housing or jacket, within the scope of this invention, jet pumps whose cores are installed in a common pipe section serving as a jacket are also referred to as pipe ejectors. In particular, a single core can contain flow-shaping components from several jet pumps, thus reducing the overall number of components required. For example, the flow-shaping components can be made, at least partially, from a plastic and / or a metal that melts at a comparatively low temperature, e.g., by injection molding, and pressed into the pipe section. This enables cost-effective mass production of the jet pumps.

[0042] Regardless of the specific relative arrangement of the at least two jet pumps, the actuating mechanism, according to at least one embodiment, comprises a rotatable disc. While this embodiment is particularly suitable for essentially circular arrangements of the jet pumps (e.g., the aforementioned radial arrangements in a plane or parallel to each other along a cylindrical surface), as the jet pumps can then be aligned directly with the actuating mechanism, this type of actuating mechanism can also be combined with any relative arrangement of jet pumps. In such cases, the different outlets of the actuating mechanism can be connected to the respective primary nozzles of the jet pumps, for example, via separate pipelines. Depending on the angular position of the rotatable disc, the at least two jet pumps can be selectively activated or deactivated.

[0043] According to at least one alternative embodiment, the actuating mechanism comprises a piston rotatable and / or linearly displaceable within a tube and / or bore, which is configured to selectively open and / or selectively close openings within a wall of the tube or bore, wherein each primary nozzle of the jet pumps is connected to one of the openings in the wall of the tube or bore. According to at least one embodiment, the piston is hollow cylindrical. R.415443-IP2

[0044] - 10 -

[0045] The mechanism is designed with one or more recesses in a shell wall of the hollow cylinder, which are configured to at least partially align with the openings in the wall of the tube or bore, depending on the position of the piston. These designs of the adjusting mechanism are particularly suitable for jet pumps arranged linearly relative to each other, but, analogous to the considerations above regarding an adjusting mechanism with a rotating disc, they can also be used for other relative arrangements of jet pumps if the primary nozzles are connected to the adjusting mechanism, for example, by means of appropriate piping. These designs of the adjusting mechanism are mechanically very simple and therefore both cost-effective and particularly precise to manufacture.

[0046] A refrigerant circuit according to the invention for a temperature control system comprises at least one jet pump unit according to the invention, a compressor for compressing a refrigerant, a refrigerant condenser for at least partially condensing the refrigerant downstream of the compressor, and a refrigerant evaporator for at least partially evaporating the refrigerant, wherein the jet pump unit is arranged such that the at least partially condensed refrigerant is supplied to it downstream of the refrigerant condenser as motive fluid and the at least partially evaporated refrigerant is supplied downstream of the refrigerant evaporator as suction fluid, and wherein downstream of an outlet of the jet pump unit a gaseous fraction of the refrigerant is supplied to the compressor on the suction side and a liquid fraction of the refrigerant is supplied to the refrigerant evaporator.In particular, a liquid phase separator can be provided downstream of the jet pump unit, designed to separate the liquid component from the gaseous component of the refrigerant. However, variants without such a liquid phase separator are also possible.

[0047] In particular, the jet pump unit or the refrigerant circuit according to the invention can be used in a temperature control system of a vehicle, for example, a vehicle that is at least partially electrically powered. The temperature control system can be used, in particular, for temperature control of the vehicle interior and / or the traction battery and / or the traction motor R.415443-IP2

[0048] - 11 -

[0049] and / or other components of the vehicle. However, it should be expressly noted that embodiments of the jet pump unit or the refrigerant circuit according to the invention can also be used in other mobile and / or stationary application scenarios, for example, for cooling and / or heating and / or dehumidifying buildings (e.g., air conditioning, heat pump, etc.). In particular, the heating and / or cooling and / or dehumidification of the building is preferably carried out by a device, especially an HVAC system (Heating, Ventilation and Air Conditioning system), preferably an air conditioner or a heat pump, which includes a jet pump unit or a refrigerant circuit according to the invention. The use of the jet pump unit or the refrigerant circuit according to the invention for heating drinking water, especially in a hot water heat pump, is also conceivable.

[0050] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawing.

[0051] It is possible, regardless of the other design features of the jet pumps, for the jet pumps to have a casing and a core arranged within the casing, wherein the core defines an internal geometry of the jet pump and wherein the casing defines an external geometry of the jet pump and is configured to mechanically support the core. For example, several jet pumps (cores) can be accommodated in a common casing, or a single core can define several jet pumps within the common casing. In particular, the core can have a first material and the casing a second material that differs from the first material, wherein the second material has higher mechanical strength and / or higher hardness than the first material and / or wherein, at a predetermined temperature, the first material has higher deformability than the second material.Due to the higher deformability of the first material, the internal contour of the jet pump can be manufactured with particularly high precision (for example, using an injection molding process, etc.). The internal contour is especially relevant for R.415443-IP2.

[0052] - 12 -

[0053] The design is crucial because it controls the flow of the motive fluid and the suction fluid. Therefore, the precision of the inner contour is also decisive for the efficiency of the jet pump. By supporting the core with the casing, which comprises the mechanically more stable second material, a high pressure resistance of the entire jet pump can still be ensured, and, for example, significantly less first material can be used for the core. Details of possible embodiments of such a jet pump with different materials in the casing and core are disclosed in the parallel patent application DE 102025145870.7, in particular in Figure 1 and the associated description.

[0054] The invention is schematically illustrated in the drawing using exemplary embodiments and is described below with reference to the drawing.

[0055] Brief description of the drawings

[0056] Figure 1 shows a jet pump as it can be used according to at least one embodiment of the invention.

[0057] Figure 2 shows a refrigerant circuit according to one embodiment of the invention.

[0058] Figure 3A shows an embodiment of a jet pump unit according to the invention.

[0059] Figure 3B shows a further embodiment of a jet pump unit according to the invention.

[0060] Figure 3C shows a further embodiment of a jet pump unit according to the invention.

[0061] Figure 3D shows a further embodiment of a jet pump unit according to the invention in a side sectional view. R.415443-IP2

[0062] - 13 -

[0063] Figure 3E shows a further embodiment of a jet pump unit according to the invention in a side sectional view.

[0064] Figure 3F shows an embodiment of an actuating mechanism for activating one or more jet pumps of a jet pump unit, for example according to Figs. 3D and 3E, as it can be used in embodiments of the invention, in a top view.

[0065] Figure 3G shows a further embodiment of a jet pump unit according to the invention in a side sectional view.

[0066] Figure 3H shows a further embodiment of an actuating mechanism for activating one or more jet pumps of a jet pump unit, for example according to Fig. 3D, 3E and 3G, as it can be used in embodiments of the invention, in a top view.

[0067] Figure 4A shows a further embodiment of an actuating mechanism for activating one or more jet pumps of a jet pump unit, for example according to Figs. 3A to 30, as it can be used in embodiments of the invention, in a top view.

[0068] Figure 4B shows the adjusting mechanism from Fig. 4A in a side view.

[0069] Figure 5A shows a further embodiment of the adjusting mechanism as it can be used in embodiments of the invention, in a top view.

[0070] Figure 5B shows the adjusting mechanism from Fig. 5A in a side sectional view.

[0071] Figure 6A shows a further embodiment of the adjusting mechanism, as it can be used in embodiments of the invention, in a top view. R.415443-IP2

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[0073] Figure 6B shows the adjusting mechanism from Fig. 6A in a perspective view.

[0074] Figure 7A shows a further embodiment of a jet pump unit according to the invention in a perspective exploded view.

[0075] Figure 7B shows the jet pump unit from Fig. 7A in a top view.

[0076] Figure 8A shows a side sectional view of a further embodiment of a jet pump unit according to the invention, in particular according to Fig.

[0077] 3A, and their connection to further components of an embodiment of a refrigerant circuit according to the invention.

[0078] Figure 8B shows a further embodiment of a jet pump unit according to the invention, in particular according to Fig. 3B, and its connection to further components of an embodiment of a refrigerant circuit according to the invention.

[0079] Figure 8C shows a side sectional view of a further embodiment of a jet pump unit according to the invention, in particular according to Fig.

[0080] 3C, and their connection to further components of an embodiment of a refrigerant circuit according to the invention.

[0081] Figure 9A shows a first embodiment of a check valve arrangement for preventing backflow of mixed fluid through inactive jet pumps in a sectional view.

[0082] Figure 9B shows a second embodiment of a check valve arrangement for preventing backflow of mixed fluid through inactive jet pumps in a sectional view.

[0083] Figure 9C shows the check valve assembly from Fig. 8B in a top view of the outlet. R.415443-IP2

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[0085] Figure 9D shows a third embodiment of a check valve arrangement for preventing backflow of mixed fluid through inactive jet pumps in a top view of the outlet.

[0086] embodiment(s) of the invention

[0087] Figure 1 shows a jet pump, as it can be used according to at least one embodiment of the invention, schematically shown by means of a longitudinal section drawing and labelled overall with 100.

[0088] The jet pump comprises a first connection interface 101 for supplying a propellant fluid to a primary nozzle 103 of the jet pump 100 and a second connection interface 102 for supplying a suction fluid to a mixing tube 104 of the jet pump 100, which is located downstream of the primary nozzle 103. In the example shown here, the primary nozzle 103 is designed as a supersonic nozzle, which accelerates the propellant fluid (given a suitable inlet pressure of the propellant fluid and a suitable pressure drop across the jet pump 100) to a velocity exceeding the relevant speed of sound. A region within the primary nozzle where the speed of sound is exceeded is marked with a dashed ellipse. This acceleration significantly reduces the pressure of the propellant fluid on its way through the primary nozzle 103 to the inlet of the mixing tube 104 (e.g., from approximately 30 bar to 2 bar).

[0089] If a suction fluid with a suitable inlet pressure, which is typically significantly lower than the inlet pressure of the propellant fluid (e.g., 2 bar), is present at the second connection interface 102, the suction fluid is accelerated by momentum transfer from the propellant fluid in the mixing tube 104 downstream of the primary nozzle 103 to the suction fluid. The propellant fluid is decelerated accordingly. Under optimal operating conditions, the propellant fluid thus falls below the speed of sound again in a final section 140 at an end of the mixing tube 104 furthest from the primary nozzle. R.415443-IP2

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[0091] Downstream of the mixing tube 104, a diffuser 105 is connected in the form of a section widening in its cross-section, which serves to further decelerate and increase the pressure in the mixed fluid (also referred to as mixing fluid). For example, under the operating conditions mentioned above, an outlet pressure of 3 to 4 bar can be achieved at the outlet of the diffuser.

[0092] In particular, the jet pump 100 can be designed such that its flow-shaping components 120 (also referred to as core 120), for example as an injection-molded part, are installed in a pipe section as a housing or jacket 110. As will be explained in more detail below, the core 120 comprises, in particular, the flow-shaping components of several jet pumps, or several cores 120 are contained in a common jacket 110.

[0093] Figure 2 shows a refrigerant circuit according to an embodiment of the invention schematically using a functional diagram and is labelled overall with 200.

[0094] The refrigerant circuit 200 comprises a compressor 210 for compressing a refrigerant, for example propane, carbon dioxide, or another suitable gas that can be at least partially condensed under the selected operating conditions, a refrigerant condenser 220, a jet pump unit 300 comprising several jet pumps 100 connected in parallel, which may be configured in particular as described with reference to Figure 1, a liquid phase separator 250, and a refrigerant evaporator 240 for transferring heat to the refrigerant. An expansion valve 245 for expanding the refrigerant is arranged upstream of the refrigerant evaporator 240.

[0095] The jet pump unit 300 can be configured, in particular, as shown in Figures 3 or 8. Depending on the specific configuration of the jet pump unit 300, the liquid phase separator 250 can be integrated into the jet pump unit 300, as can be seen in Figure 8, and, for example, in the middle below the jet pumps 100 (Fig. 8A), around the jet pumps 100 (Fig. 8B), or in the middle between the jet pumps 100 (Fig. 8C). R.415443-IP2

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[0097] This reduces the required installation space and offers the advantage that the liquid phase separator 250 is thermally isolated from its surroundings by the jet pumps 100 (Figs. 8A, 8C), which increases the overall efficiency of the refrigerant circuit 200. In the example shown in Figure 8B, a rotational movement of the mixed fluid can be induced by tangentially extracting the liquid, thereby accelerating the separation between the liquid and gas phases.

[0098] As shown in Figure 2, the jet pump unit 300 is used in the refrigerant circuit 200 for pre-compression of the expanded refrigerant 242 exiting the refrigerant evaporator 240. The liquid phase of the compressed refrigerant 231 after exiting the refrigerant condenser 220 (and, in the example shown, a further heat exchanger 230, which is provided for transferring heat between the compressed refrigerant on the pressure side of the compressor and the refrigerant 253 supplied to the compressor on the suction side) is under high pressure and is directed as a motive fluid into the primary nozzle(s) 103 of the jet pump(s) 100 for acceleration and expansion. On the secondary side (connection interface 102), the expanded refrigerant 242 is drawn in as a suction fluid at evaporator pressure level.The mixture 251 of propellant and suction fluid, pre-compressed by the jet pump unit 300, is directed into the liquid phase separator 250. The liquid phase 252 separated there is then directed through the expansion valve 245 to the refrigerant evaporator 240. The vapor component 253 of the refrigerant separated in the liquid phase separator 250 is returned to the compressor 210 via the heat exchanger 230. The pre-compression by the jet pump unit 300 reduces the compression work required in the compressor 210.

[0099] Figure 3A schematically illustrates a first embodiment of a jet pump unit according to the invention, without an actuating mechanism, in a perspective top view using partial sectional drawings and is designated overall by 300. A first jet pump 100, which can be configured in particular as explained with reference to Figure 1, is connected in parallel with further jet pumps 100, which can be configured identically to the first jet pump 100. The first connection interfaces 101 of R.415443-IP2

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[0101] Jet pumps 100 are arranged on an inner circle 301. In this embodiment, the jet pumps 100 themselves, or the central axes of the mixing tubes 104, are arranged radially to the inner circle 301 in a common plane, so that the outlets of the diffusers 105 also lie on an outer circle 302, since in this example all of the jet pumps 100 are identical in design.

[0102] Furthermore, the jet pump unit 300 has a common pressure line 310 (see, for example, Fig. 8A) for supplying the motive fluid to the first connection interfaces 101 of the parallel-connected jet pumps 100 and a common actuating mechanism for selectively opening and closing the common pressure line 310 for individual or all of the parallel-connected jet pumps 100. Various versions of the common actuating mechanism are shown in Figures 4 to 7 and are explained in more detail below. Regardless of the specific design of the actuating mechanism, it can, in particular, be arranged within the inner circle 301 of the jet pump unit shown in Fig. 3A.

[0103] In the example shown in Fig. 3A, the jet pumps 100 can be provided in the form of one or more injection-molded parts (“core” 120) inserted into a common shell 110, which here, for example, consists of two essentially disc-shaped elements. Alternatively, the core 120 and shell 110 can also be composed of, for example, deep-drawn sheet metal parts, for example, welded together. The flow-shaping components of the jet pumps (primary nozzle 103, secondary connection interface 102, mixing tube 104, and diffuser 105) are molded into the core 120. The shell 110 mechanically supports the core 120 and has a connection port for the common suction line 330, which, in the example shown, encompasses a space within the shell 110 surrounding the jet pumps 100.

[0104] Figure 3B shows a second embodiment of a jet pump unit according to the invention (also without an actuating mechanism) schematically illustrated in a perspective top view using partial sectional drawings and, for the sake of clarity, is also designated as 300. This differs from the embodiment shown in Fig. 3A R.415443-IP2.

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[0106] The first embodiment shown differs from the second embodiment shown in Fig. 3B, particularly in that in the latter, the first connection interfaces 101 of the jet pumps 100 are arranged within a cylindrical surface. In this embodiment, the jet pumps 100 themselves, or rather the central axes of the mixing tubes 104, are also arranged geometrically parallel to each other within the cylindrical surface. In the example shown in Fig. 3B, the jet pumps 100 are provided in the form of one or more injection-molded parts ("core" 120) which are inserted into a common shell 110, which here consists, for example, of a pipe section. The flow-shaping components of the jet pumps (primary nozzle 103, secondary connection interface 102, mixing tube 104, and diffuser 105) are molded into the core 120. The shell 110 mechanically supports the core 120.

[0107] Figure 3C schematically illustrates a third embodiment of a jet pump unit according to the invention (again without an actuating mechanism) in a perspective top view using partial sectional drawings and is also designated as 300. In the example shown here, the first connection interfaces 101 of the jet pumps 100 are arranged on a circle, in contrast to the embodiments shown in Figures 3A and 3B. In this embodiment, the jet pumps 100 themselves, or rather the central axes of the mixing tubes, are also arranged geometrically parallel to each other on the circle (or axially along a cylindrical shell that includes the circle).

[0108] In the example shown in Fig. 3C, the jet pumps 100 are provided in the form of one or more injection-molded parts (“core” 120) which are inserted into a common shell 110, which here consists, for example, of a pipe section. The flow-shaping components of the jet pumps (primary nozzle 103, secondary connection interface 102, mixing tube 104, and diffuser 105) are molded into the core 120. The shell 110 mechanically supports the core 120 and has a connection port for a common suction line 330, which, in the example shown, includes a circumferential groove extending around the outside of the core 120 with axially extending branch channels for supplying the suction fluid to the secondary connection interfaces 102 of the individual jet pumps. Between the jet pumps 100 (inside R.415443-IP2)

[0109] - 20 -

[0110] Within the core 120) there is a cavity into which (as shown in Figure 8C) further components of a refrigerant circuit can be installed. This cavity is accessible, for example, via an opening located in the bottom of the cavity (shown off-center in Figure 3C).

[0111] Figures 3D to 3H schematically illustrate further embodiments of jet pump units (Figs. 3D, 3E, 3G) and their actuating mechanisms (Figs. 3F, 3H) using sectional drawings. The variants shown here differ from the jet pump units depicted in Figures 3A to 3C, particularly in that the individual jet pumps 100 in Figures 3D, 3E, and 3G are arranged linearly, i.e., parallel to each other and lying in a common plane. As explained earlier, even a slight deviation (up to 10°) from ideal parallelism of the jet pumps relative to each other is considered geometrically parallel. Similarly, the tolerance range explained earlier (angle of max. 5° between the common plane and the gross flow direction of the respective jet pump 100) applies to the common plane.

[0112] In the example shown in Figure 3D, a first variant of the linearly arranged jet pump unit 300 is depicted, in which a first jet pump 100, which can be configured in particular as explained with reference to Figure 1, is connected in parallel with, in the example shown, two further jet pumps 100, which can be configured in particular identically to the first jet pump 100. The jet pumps 100 are also arranged geometrically parallel to each other and lying in a common plane, as explained above.

[0113] The jet pump unit 300 has a common pressure line 310 for supplying the motive fluid to the parallel-connected jet pumps 100 and a common actuating mechanism 520 for selectively opening and closing the common pressure line 310 for individual or all of the parallel-connected jet pumps 100. The common pressure line 310 can, for example, be housed in a terminal block into which the tube ejectors 100 can be soldered. R.415443-IP2

[0114] - 21 -

[0115] In the example shown here, the actuating mechanism 520 has a (hollow cylindrical) piston with an axial bore, which, in the closed position, blocks the inlet on the primary side to the jet pumps 100. The further the piston is pulled outwards, the more of the jet pumps 100 are released and supplied with motive fluid on the primary side. The motive fluid can be supplied, for example, through the axial bore in the piston. However, a solid piston can also be used, with the supply line connected laterally to the tube in which the piston is guided.

[0116] The common actuating mechanism 520, which can be actuated, for example, by means of an electromechanical actuator (not shown separately here) or passively controlled (e.g., using a thermal wax that changes its spatial expansion with temperature, or a bimetallic strip), selectively activates the respective jet pumps 100, which then pump suction fluid from the second connection interface. In the example shown, this second interface is permanently supplied with suction fluid from a common suction line 330, for example, from the refrigerant evaporator 240 shown in Figure 2. The pre-compressed mixed flow at the outlet of the jet pumps 100 then mixes from all jet pumps 100.

[0117] The number of active jet pumps 100 is determined by the insertion depth of the piston of the actuating mechanism 520 into the common pressure line 310.

[0118] In a second variant of this linear design of the jet pump unit 300, shown in Figure 3E, the actuating mechanism (designated 520A in Figure 3E) comprises a hollow cylindrical piston instead of the end-open piston. This piston has radial recesses 322 through which the motive fluid can exit the piston when these recesses 322 overlap or coincide with corresponding openings 312 to which the respective jet pumps 100 are connected. In this variant of the jet pump unit 300 as well, the piston must be moved translationally into the desired position to activate or deactivate the jet pumps 100. R.415443-IP2

[0119] - 22 -

[0120] Figure 3F also shows a third variant 520B for the linear actuating mechanism of the jet pump unit 300. In this third variant, compared to the second variant 520A, the piston of the actuating mechanism 520B is not provided with circular recesses 322 to supply the openings 312 with the motive fluid, but rather with recesses (in the form of elongated slots) 324 oriented axially along the piston. These elongated slots or recesses 324 have, for example, a length that allows at least two of the openings 312 to be aligned with the same elongated slot or recess 324 simultaneously, so that one recess 324 can supply several jet pumps 100 at the same time. Thus, in this third variant as well, the piston of the actuating mechanism 520B is moved translationally in the axial direction to activate or deactivate the desired jet pumps 100.However, by means of the recesses 324 in the form of elongated holes, continuous adjustment of the piston is possible in this case, in contrast to the second variant 520A, where activation of the jet pumps 100 only occurs in discrete piston positions, namely precisely when the respective recesses 322 exactly coincide with the openings 312. In particular, the elongated holes 324 therefore also allow for greater tolerances with regard to the position of the piston.

[0121] Figure 3G shows another variant of the linear arrangement of the jet pump unit 300. The variant shown in Figure 3G is essentially identical to the variants described with reference to Figures 3D-3F, but differs from them in particular in that the actuating mechanism 520C shown in Figure 3G has a piston that is not moved translationally to select the different actuating options, but by a rotation about the piston axis. Analogous to the second and third variants (Fig.

[0122] 3E, 3F) are thereby brought into alignment by the rotation of the piston with the recesses 322, 324 in the wall of the hollow cylinder forming the piston and the openings 312 in the wall of the common pressure line 310, thus activating the jet pumps 100 connected to the respective openings 312. R.415443-IP2

[0123] - 23 -

[0124] The recesses 322, 324 of the adjusting mechanism 520 C can, for example, be designed as substantially circular bores 322 or as elongated holes 324 oriented in the circumferential direction of the piston, as shown in Fig. 3G, whereby in the case of the elongated holes 324 a continuous adjustment is possible (which also allows a greater tolerance with respect to the angular position of the piston), while in the case of individual bores 322 only discrete rotation angles lead to a collision between the respective recess 322 and the associated opening 312.

[0125] Figure 3H shows a further embodiment of the (linear) actuating mechanism, designated 520D. The actuating mechanism 520D conceptually combines aspects of the actuating mechanisms 520, 520A, 520B, and 520C, as it can be positioned to activate or deactivate the jet pumps by means of both translational and rotational movement. In the example shown, only a triangular recess 524 is provided, which extends axially and circumferentially across the piston wall such that, depending on the axial and / or rotational position of the piston, it supplies any one of the openings 312, several adjacent openings, or all openings 312 simultaneously with the motive fluid, as shown schematically in Figure 3H.This design of the actuating mechanism 520D is particularly advantageous in cases where not all jet pumps 100 of the jet pump unit 300 have the same capacity, since the individual control of each jet pump 100 allows the most suitable combination of jet pumps for the current performance requirement to be specifically activated. For this purpose, recess shapes other than the triangular shape shown here can also be used to increase the number of possible combinations, for example, to activate jet pumps that are not adjacent to each other simultaneously without intervening jet pumps.

[0126] Figures 4 to 7 show different (further) variants of actuating mechanisms 320, 320A, 420, 420B for controlling the jet pump unit 300 or other jet pump units. For each embodiment, an exemplary position of the respective actuating mechanism is shown, in order to R.415443-IP2

[0127] - 24 -

[0128] to illustrate the functioning of the different variants of the actuating mechanism. One such actuating mechanism is, for example, arranged within the inner circle 301 of the jet pump unit 300 shown in Fig. 3A or below the jet pump unit 300 shown in Figures 3B and 3C and supplies the individual jet pumps 100 with motive fluid.

[0129] The actuating mechanism has a common pressure line 310 for supplying the motive fluid to the first connection interfaces 101 of the parallel-connected jet pumps 100 and is designed for selectively opening and closing the common pressure line 310 for one or all of the parallel-connected jet pumps 100.

[0130] The actuating mechanism 320 is shown in a schematic top view in Figure 4A and in a side view in Figure 4B. The actuating mechanism 320 comprises a rotary disk 340 with differently sized recesses 324, through which the propellant fluid can be directed via openings 312 in a housing 350 of the actuating mechanism 320 to the primary nozzles 103 of the jet pumps 100. In the example shown here, the openings 312 are arranged radially in the housing 350. However, it is also conceivable that the openings extend axially out of the housing 350. Depending on the specific design of the jet pump unit, a suitable configuration can therefore be selected so that the openings 312 lead directly into the respective connection interfaces 101. Alternatively, for example, pipelines (not shown) can be provided that direct the propellant fluid from the respective opening 312 to the respective connection interface 101.This option also exists for all other variants of the actuating mechanism described here. The rotary disc 340 is solidly formed between the recesses 324 and is suitable for closing the openings 312. In the example shown, the recesses 324 extend sector-like over sections of varying sizes in the circumferential direction of the rotary disc 340, so that, depending on the rotational position of the rotary disc 340 relative to the openings 312, none, one, or several of the openings 312 can be aligned with the recesses 324, thereby activating (supplying with motive fluid) the jet pump connected to the respective opening, while jet pumps whose associated R.415443-IP2.

[0131] - 25 -

[0132] Opening 312 is deactivated if it does not overlap with any of the recesses 324. Advantageously, the actuating mechanism 320 can be attached directly to the casing 110 of the jet pump unit 300, for example, by having the housing 350 of the actuating mechanism 320 have an outer diameter corresponding to the diameter of the inner circle 301 (Fig. 3A), so that the housing 350 can be welded into the casing 110 on the side where the primary nozzles 103 of the jet pumps are located. In the case of the variants from Fig. 3B and 30, for example, the housing 350 of the actuating mechanism 320 can be welded to the casing 110 on the side where the primary nozzles 103 of the jet pumps are located. In this way, the openings 312 can open directly into the first connection interfaces 101 (or the primary nozzles 103).

[0133] The supply of the propellant fluid from the common pressure line 310 to the recesses 324 can, for example, be from an axial side of the housing 350 of the actuating mechanism 320.

[0134] For clarity, only four openings 312 are shown in each of the actuating mechanisms depicted here. Typically, however, a corresponding actuating mechanism with an equally large number of openings 312 can be provided for any number of jet pumps 100, so that each jet pump can be individually activated and / or deactivated. It is also possible to connect several jet pumps to a common opening 312 in order to activate and deactivate them together.

[0135] The common actuating mechanism 320, which can be actuated, for example, by means of an electromechanical actuator (designated 345 in Figure 8A, not shown separately in the other figures) or passively (e.g., using a thermal wax that changes its spatial expansion with temperature, or a bimetallic strip), selectively activates the respective jet pumps 100 and pumps suction fluid from the second connection interface 102, which in the example shown is permanently supplied with suction fluid from the common suction line 330, for example, from the refrigerant evaporator 240 shown in Figure 2. The pre-compressed R.415443-IP2

[0136] - 26 -

[0137] The mixed flow (labeled 251 in Figures 2 and 7) at the outlet of the jet pumps 100 then mixes from all jet pumps.

[0138] The number of active jet pumps 100 is determined, as mentioned, by the rotary position of the rotary disc 340 of the actuating mechanism 320.

[0139] A second embodiment of the actuating mechanism of the jet pump unit is shown in Figure 5A in a top view and in Figure 5B in a side sectional view and is designated 320A. In this embodiment, the actuating mechanism 320A comprises, instead of the rotary disk 340 with separate recesses 324 shown in Figure 4A, a rotary disk 340A with a complex or irregularly shaped recess 324A, which functionally corresponds to the recesses 324 of the first embodiment 320, wherein, however, there is a connection within the rotary disk 340A between the individual "arms" or end sections of the recess 324A, so that the motive fluid from the common pressure line 310 can be fed into each of these end sections of the recess 324A or, as shown here, into this connection between the end sections of the recess 324A in order to reach all end sections of the recess 324A.The direction from which the motive fluid is supplied to the rotary disk 340A is, in principle, irrelevant. Instead of the recesses 324, 324A shown in Figures 4 and 5, each extending over a larger angular range, several individual recesses, whose dimensions correspond essentially exactly to the dimensions of the openings 312, can also be provided at different angular intervals from one another, so that discrete positions of the rotary disk 340, 340A lead to the activation of the jet pumps 100, while intermediate positions can be used to deactivate all jet pumps.

[0140] Figure 6A shows a third embodiment of an actuating mechanism for a jet pump unit according to the invention in a top view and is designated 420 in its entirety. Figure 6B shows the actuating mechanism 420 in a perspective view. R.415443-IP2

[0141] - 27 -

[0142] This third embodiment of the actuating mechanism 420 differs from the two previously explained embodiments 320, 320A in particular in that it has a variable geometry of the cavity through which the propellant fluid is guided in the actuating mechanism.

[0143] Instead of a rotary disk with defined recesses 324, a rotary disk 340B is provided, on which a cylindrical pin is arranged centrally, from which a partition 440 extends radially outwards. By rotating the rotary disk 340B, the position or angular position of the partition 440 within the housing (which in the illustrated embodiment is significantly thicker than before) is changed.

[0144] Furthermore, within the housing 350, a fixed wall 450 of the housing 350, also extending radially inwards into the housing 350, is arranged. This wall terminates internally with the cylindrical pin of the rotary disk 340B, inwards ("downwards") with the rotary disk 340B, and outwards ("upwards") with a housing cover, in particular (as far as possible) gas-tight, in order to define an angular range through which the motive fluid can flow as a cavity within the housing 350. In order to provide the largest possible angular range for the different positions of the actuating mechanism 420, the common pressure line 310, in the illustrated example, opens into the housing 350 of the actuating mechanism 420 from "above" in the immediate vicinity of the fixed wall 450 in Figure 6. The outlets orOpenings 312, which supply the individual jet pumps with the motive fluid, can be arranged circumferentially across the top surface or the upper surface and / or a lateral surface of the housing 350 and are always supplied with the motive fluid when they are located, together with the connection of the common pressure line 310, within the cavity enclosed by the fixed wall 450 and the movable partition 440. If an opening 312 is located outside this cavity, it is not supplied with the motive fluid and the jet pump 100 connected to it is deactivated. R.415443-IP2.

[0145] - 28 -

[0146] Figure 7 schematically shows a further embodiment of the jet pump unit 300 according to the invention in a top view (Fig. 7A) and a perspective exploded view (Fig. 7B). In the variant of the jet pump unit 300 shown in Figure 7, an actuating mechanism 420B is used, which essentially corresponds to the actuating mechanism 420 shown in Figure 5. In addition to the partition 440 for releasing or blocking the supply of the propellant fluid to the primary nozzles 103, the actuating mechanism 420B has a further partition 440B, which, on the side of the diffuser outlets 105, defines an angular range through which the mixing fluid 251 can flow, together with another fixed wall 450B. In the example shown here, the partitions 440 and 440B are mounted together on the rotary disk 340B.This not only controls the primary-side supply of the propellant fluid by means of the adjusting mechanism 420B, but also enables the discharge of the mixing fluid 251 only from the jet pumps 100 that are also supplied with propellant fluid. This configuration prevents the mixing fluid 251 from flowing back into the common suction line 330 through inactive jet pumps 100.

[0147] In principle, the walls shown here as fixed walls 450, 450B can also be designed to be movable, requiring two actuators for the relative position of the partition walls 440, 440B with respect to the walls 450, 450B. While this entails increased control complexity, it allows, for example, finer gradations in the overall capacity of the jet pump unit 300, particularly in cases where differently sized jet pumps 100 are used. Furthermore, all of the jet pump units can be subjected to essentially the same load with such a dual actuator mechanism, as not always the same jet pumps are activated. This results in more uniform wear and thus an overall longer service life for the jet pump unit 300. This design option applies to both actuator 420 and actuator 420B.

[0148] In the case of the actuating mechanisms 320, 320A, the currently inactive R.415443-IP2 can also be used to prevent backflow of the mixed fluid into the diffusers 105.

[0149] - 29 -

[0150] For jet pumps, a mechanism essentially identical to the input-side actuating mechanism 320, 320A can be used to release the output of the active jet pumps 100, while the output of the inactive jet pumps 100 is closed by the corresponding mechanism. In particular, such a mechanism, which selectively closes or releases the output of the jet pumps 100, can also be mechanically coupled to the actuating mechanism 320320A or activated by the same actuator. Furthermore, it is possible to install dedicated check valves at the outputs of the diffusers 105 to accomplish this.

[0151] Regardless of the specific design of the actuating mechanism 320, 320A, 420, 420B, the rotary disc 340, 340A, 340B and the housing 350 can each be made of the same or different materials. In particular, a pressure-resistant material, such as a metal like aluminum, an aluminum alloy, or steel, is preferably used for the housing. For the rotary disc 340, 340A, 340B, a material that exhibits low frictional resistance in contact with the housing material 350 can be used, such as a plastic like polytetrafluoroethylene (PTFE) or the like. Combinations of several materials can also be used, for example, a housing body and a rotary disc core made of a metal, each with a plastic coating applied to improve the friction and sealing properties of the system.

[0152] Figure 8A schematically shows a further embodiment of a jet pump unit 300 according to the invention in a side sectional view. This view shows in particular the connection of the jet pump unit 300 to other components of a refrigerant circuit. Here, the jet pump unit 300 is equipped, purely by way of example, with the actuating mechanism 420 shown in Figure 6. In the example shown, a liquid phase separator 250 is provided below the jet pump unit 300. This liquid phase separator 250 is housed together with the jet pumps in a common housing, the cover of which is essentially formed by the jet pump unit 300 or the casing 110 of the jet pumps 100. R.415443-IP2

[0153] - 30 -

[0154] Gaseous refrigerant from the gas phase 253 and liquid refrigerant from the liquid phase 252 can be extracted from the liquid phase separator 250 via branch lines. By positioning the liquid phase separator 250 below the jet pumps, at least partial thermal insulation of the liquid phase separator 250 from the environment of the jet pump unit 300 is achieved, which increases the overall efficiency of the system.

[0155] The remaining features correspond to the already explained configurations of the jet pump unit 300, so reference is made to the relevant explanations.

[0156] Figure 8B schematically shows a further embodiment of a jet pump unit 300 according to the invention in a perspective view. This view shows, in particular, the connection of the jet pump unit 300 to other components of a refrigerant circuit. Here, the jet pump unit 300 is equipped, purely by way of example, with the actuating mechanism 320A shown in Figure 5. In the example shown, a liquid phase separator 250 is provided around the jet pump unit 300, so that the jet pumps 100 are located radially inside the liquid phase separator 250. This liquid phase separator 250 is housed together with the jet pumps in a common casing, which here is essentially formed from the jacket 110 of the jet pumps 100, an outer pipe section 113, and a dome-shaped cover 114.In the example shown here, the core 120 is pressed into the shell 110 and can be secured in its position, for example, by means of beads.

[0157] In the example shown here, the liquid phase is extracted tangentially from the liquid phase separator 250, thereby inducing a rotational movement within the liquid phase separator (indicated by curved arrows in Fig. 8B), which supports the separation of the gas and liquid phases. The gas phase 253 can, for example, be extracted axially. R.415443-IP2

[0158] - 31 -

[0159] The remaining features of the embodiment shown in Fig. 8B correspond to the embodiment of the jet pump unit 300 already explained in particular with regard to Fig. 3B, so that reference is made to the relevant explanations.

[0160] Figure 8C schematically shows a further embodiment of a jet pump unit 300 according to the invention in a side sectional view. This view shows, in particular, the connection of the jet pump unit 300 to other components of a refrigerant circuit. Here, the jet pump unit 300 is essentially identical in design to the jet pump unit shown in Figure 3C and, purely by way of example, is equipped with the actuating mechanism 320A shown in Figure 5. In the example shown, a liquid phase separator 250 is provided in the center of the jet pump unit 300, i.e., radially inside between the jet pumps 100. This liquid phase separator 250 is housed together with the jet pumps in a common housing, which is essentially formed from the casing 110 of the jet pumps 100.In the example shown here, the casing 110 has an outer (113) and an inner (114) pipe section, the inner pipe section 114 being cranked at its upper end so that the outlet of the diffuser 105 of the jet pumps 100 assumes a defined position in the axial direction. In this example, the core 120 is pressed into the casing 110 and secured in its position by means of grooves 112. Furthermore, in this example, check valves 360 are provided to prevent backflow of compressed fluid from the liquid phase separator 250 into jet pumps that are currently inactive. Instead of the check valves 360 shown here, a mechanism essentially identical to the inlet-side actuating mechanism 320A can also be used to open the outlet of the active jet pumps 100, while the outlet of the inactive jet pumps 100 is closed by the corresponding mechanism.In particular, such a mechanism, which selectively closes or releases the outlet of the jet pumps 100, can be mechanically coupled to the actuating mechanism 320 or activated by the same drive. R.415443-IP2.

[0161] - 32 -

[0162] Gaseous refrigerant from the gas phase 253 and liquid refrigerant from the liquid phase 252 can be extracted from the liquid phase separator 250 via central branch lines. The central arrangement of the liquid phase separator 250 between the jet pumps provides thermal insulation of the liquid phase separator 250 from the environment of the jet pump unit 300, thus increasing the overall efficiency of the system.

[0163] The remaining features of the jet pump unit shown in Figure 80 correspond to the embodiment of the jet pump unit 300 already explained in connection with Figure 30, so reference is made to the relevant explanations.

[0164] Figure 9 schematically shows three different configurations of check valve arrangements for preventing backflow of mixed fluid through inactive jet pumps in lateral sectional views (Fig. 9A, Fig. 9B) and top views of the outlet (Fig. 90, Fig. 9D), and is designated 360A (Fig. 9A), 360B (Fig. 9B, 90), and 3600 (Fig. 9D), respectively. The check valve arrangements 360A, 360B, and 3600 are provided at the outlet of the diffusers 105 to prevent backflow of compressed fluid from the liquid phase separator 250 into jet pumps that are currently inactive. For the sake of clarity, Figures 9A and 9B, C show the check valve arrangements for a linear arrangement of the jet pumps 100, while Figure 9D shows an embodiment for a substantially cylindrical jet pump unit in which the jet pumps 100 are arranged on a circular line.It is understood that the designs of Figures 9A and 9B, C can also be adapted for cylindrical or any other shaped jet pump units by adapting the arrangement of the individual check valves within the check valve arrangement to the relative arrangement of the individual jet pumps within the jet pump unit.

[0165] The check valve assembly 360A comprises several (here four) check valves 365A, each having a plug-shaped closing element 361A and a spring element 363A, here in the form of a coil spring, which pushes the closing element 361A towards the outlet of the diffuser 105. R.415443-IP2

[0166] - 33 -

[0167] In the example shown, check valves 365A are mounted on a common plate 362A, so that the mounting of the check valve assembly 360A on the jet pump unit 300 can be carried out easily in one step.

[0168] The check valve arrangement 360B according to Figures 9B, C differs from that shown in Figure 9A, particularly in the type of check valves designated here as 365B: Instead of plug-shaped closing elements 361 A from Figure 9A, the embodiment according to Figures 9B, C provides closing elements 361 B in lamellar form, for example thin metal sheets or plastic film strips, which are pressed against or away from the opening of the diffuser 105 by the fluid flow. Lifting catches 364B limit the range of motion of the closing elements 361 B to ensure that they are close enough to the opening of the respective diffuser 105 so that, in the event of deactivation of the jet pump in question, they are forced against the opening by the overpressure building up downstream of the diffuser 105.The lifting catches 364B can, in particular in an area intended for contacting the closing elements, have a recess 366B to ensure rapid closing of the relevant check valve 365B in the event of deactivation. The recess 366B is designed to allow fluid flowing towards the no longer activated diffuser 105 to flow towards the relevant closing element 361B, so that it can be forced against the opening of the inactive diffuser 105. In this embodiment 360B as well, the closing elements 361B together with the lifting catches 364B can be pre-assembled on a common plate 362B and attached to the steel pump unit as a single assembly.

[0169] Figure 9D shows a further embodiment of a check valve arrangement in a top view of the outlet and is designated 360C. This embodiment 360C is essentially identical to the embodiment 360B from Figure 9B, C, so reference is made to the corresponding descriptions. However, embodiment 360C differs from embodiment 360B by the essentially circular plate 362C, on which the individual check valves 365B are pre-mounted such that the closing elements 361B are located on R.415443-IP2

[0170] - 34 -

[0171] a circular line 367C. As already mentioned, the check valves are advantageously arranged on the plate 362C such that the positions of the closing elements 361C correspond to the positions of the outlets of the diffusers 105 of the jet pump unit 300, for which the check valve arrangement 360C is provided. In the simplified example shown here, the individual jet pumps 100 of the associated jet pump unit would accordingly also be arranged such that the outlets of the diffusers lie on the circular line 367C (or a circular line with identical diameter).

[0172] Instead of the check valve arrangements 360A, 360B, 360C shown here, a mechanism essentially identical to the inlet-side actuating mechanism 320A can also be used to release the output of the active jet pumps 100, while the output of the inactive jet pumps 100 is closed by the corresponding mechanism. In particular, such a mechanism, which selectively closes or releases the output of the jet pumps 100, can be mechanically coupled to the actuating mechanism 320 or activated by the same actuator.

[0173] It is understood that the features described separately here can be combined with one another without any problems, so that the embodiments described in the figure description are merely to be understood as examples of the concept underlying the invention. For example, linear embodiments of the actuating mechanism (e.g., from Figs. 3D to 3h) can also be combined with non-linear arrangements of jet pumps 100 (e.g., according to Fig. 3A). The same applies to other combinations of features that have been described with regard to different embodiments.

Claims

R.415443-IP2 - 35 - Claims 1. Jet pump unit (300) with at least two jet pumps (100) connected in parallel for pumping a suction fluid (242) in a refrigerant circuit (200) of a temperature control system using a propellant fluid (231) by utilizing the Bernoulli effect, wherein each of the at least two jet pumps has a primary nozzle (103) for accelerating the propellant fluid, a secondary connection interface (102) for supplying the suction fluid, a mixing tube (104) downstream of the primary nozzle (103) and downstream of the secondary connection interface (102), and a diffuser (105) downstream of the mixing tube (104), wherein the jet pump unit has a common pressure line (310) for supplying the propellant fluid to the jet pumps connected in parallel (100) and a common actuating mechanism (320, 320A, 420, 420B, 520, 520A, 520B, 520C, 520D) for selectively opening and closing the common pressure line (310) for one, several, or all of the parallel-connected jet pumps (100).

2. Jet pump unit (300) according to claim 1, wherein the actuating mechanism (320, 320A, 420, 420B) comprises a rotatable rotary disk (340, 340A, 340B) within a housing (350), which is configured to selectively release and / or selectively close openings (312) of the housing (350), wherein each of the primary nozzles (103) of the jet pumps is connected to at least one of the openings (312) of the housing (350).

3. Jet pump unit (300) according to claim 2, wherein the rotary disk (340, 340A) has at least one recess (324, 324A) and / or depression, wherein the at least one recess or depression is configured to at least partially coincide with the openings (312) of the housing (350) depending on a rotational position of the rotary disk (340, 340A) within the housing (350). R.415443-IP2 - 36 - 4. Jet pump unit (300) according to claim 3, wherein the at least one recess (324, 324A) or depression is configured to release one or more of the openings (312) of the housing (350) simultaneously.

5. Jet pump unit (300) according to claim 2, wherein the rotary disk (340B) is equipped with a partition (440) which, together with a fixed wall (450) of the housing (350) projecting inwards into the housing (350) and contacting the rotary disk (340B), or with a second partition of a second rotary disk, defines an angular range through which the motive fluid can flow, wherein the openings (312) are arranged distributed circumferentially over the housing (350) and, depending on a rotational position of the partition (440), are located inside or outside the angular range through which the motive fluid can flow.

6. Jet pump unit (300) according to claim 5, wherein the rotary disk (340B) is equipped with a further partition (440B) which, together with a further fixed wall (450B) of the housing (350) projecting inwards into the housing (350) or a further second partition of the second rotary disk, defines an angular range through which a mixing fluid (251) formed from the motive fluid and the suction fluid can flow, wherein, depending on a rotational position of the further partition (440B), the openings are outlets of the diffusers (105) located inside or outside the angular range through which the mixing fluid (251) can flow.

7. Jet pump unit (300) according to one of the preceding claims, wherein the actuating mechanism (520, 520A, 520B, 520C, 520D) comprises a piston rotatable and / or linearly displaceable within a tube and / or bore, which is configured to selectively open and / or selectively close openings (312) within a wall of the tube or bore, wherein each of the primary nozzles (103) of the jet pumps (100) is connected to at least one of the openings (312) in the wall of the tube or bore. R.415443-IP2 - 37 - 8. Jet pump unit (300) according to claim 7, wherein the piston is designed in a hollow cylindrical shape and has one or more recesses (322, 324) in a shell wall of the hollow cylinder, which are arranged to at least partially coincide with the openings (312) in the wall of the tube or bore, depending on a position of the piston.

9. Jet pump unit according to claim 7 or 8, wherein the tube or bore in which the piston of the actuating mechanism (520, 520A, 520B, 520C, 520D) is received is part of the common pressure line (310).

10. Jet pump unit (300) according to one of the preceding claims, wherein the at least two jet pumps (100) are arranged leading away from the common pressure line (310) within a common plane, and / or wherein the at least two jet pumps are arranged geometrically parallel to each other axially along and / or within a cylinder shell, and / or wherein the at least two jet pumps are arranged geometrically parallel to each other and lying in a common plane.

11. Refrigerant circuit (200) for a temperature control system comprising at least one jet pump unit according to one of the preceding claims, a compressor (210) for compressing a refrigerant (253), a refrigerant condenser (220) for at least partially condensing the refrigerant downstream of the compressor (210), and a refrigerant evaporator (240) for at least partially evaporating the refrigerant, wherein the jet pump unit is arranged such that the at least partially condensed refrigerant (231) is supplied to it downstream of the refrigerant condenser (220) as a motive fluid in the common pressure line and the at least partially evaporated refrigerant (242) is supplied downstream of the refrigerant evaporator (240) as a suction fluid, and wherein downstream of an outlet of the jet pump unit a gaseous fraction (253) of the refrigerant is supplied to the suction side of the R.415443-IP2 - 38 - compressor (210) and a liquid portion (252) of the refrigerant is directed to the refrigerant evaporator (240).

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