Delivery device for a fuel cell system for conveying and / or recirculating a gaseous medium, in particular hydrogen

Description

State of the art

[0001] The present invention relates to a conveying device for a fuel cell system for conveying and / or recirculating a gaseous medium, in particular hydrogen, which is intended in particular for use in vehicles with a fuel cell drive.

[0002] In the automotive sector, gaseous fuels will play an increasingly important role alongside liquid fuels in the future. Particularly in vehicles with fuel cell propulsion, hydrogen gas flows must be controlled. Unlike liquid fuel injection, where the gas flows are controlled discontinuously, the gas is drawn from at least one high-pressure tank and fed via a supply line of a medium-pressure piping system to the delivery unit. This delivery unit then transports the gas via a connecting line of a low-pressure piping system to a fuel cell.

[0003] From DE 10 2017 222 390 A1, a conveying device for a fuel cell system for conveying and / or recirculating a gaseous medium, in particular hydrogen, is known, comprising a side channel compressor, a jet pump driven by a motive jet of a pressurized gaseous medium, and a metering valve. The pressurized gaseous medium is supplied to the jet pump via the metering valve, wherein an anode outlet of a fuel cell is fluidically connected to an inlet of the conveying device, and wherein an outlet of the conveying device is fluidically connected to an anode inlet of the fuel cell.

[0004] The fuel cell system known from DE 10 2017 222 390 A1 can have certain disadvantages. The components of the pumping system, in particular the side channel blower, a high-pressure injector (HGI), and the jet pump, are at least partially connected to each other and / or to the fuel cell and / or to other components of the pumping system via fluidic connections in the form of pipes and, if applicable, an additional distribution plate with internal channels. The components are at least partially separate assemblies connected to each other by pipes. This results in numerous flow deflections and thus flow losses, which reduces the efficiency of the pumping system.

[0005] Furthermore, arranging the components metering valve and / or jet pump and / or side channel blower as separate assemblies has the disadvantage that they collectively form a large surface area relative to the installation space and / or geometric volume. This promotes rapid cooling, especially during extended periods of vehicle inactivity, which can lead to increased ice bridge formation and thus increased damage to the components and / or the fuel cell system. This, in turn, can reduce the reliability and / or service life of the pumping system and / or the fuel cell system.A further disadvantage is the poor cold-start performance of the components metering valve and / or jet pump and / or side channel compressor and / or the fuel cell system and / or the overall vehicle, since heating energy and / or thermal energy must be introduced individually into the components side channel compressor and / or jet pump and / or metering valve, whereby the components are arranged far apart and thus each component must be heated separately, especially at temperatures below 0° Celsius in order to eliminate possible ice bridges.

[0006] Furthermore, a separate housing must be provided for each of the components side channel blower, jet pump and metering valve, which leads to high manufacturing costs and / or material costs.

[0007] DE 10 2010 035860 A1, GB 2 260 368 A and EP 2 538 480 A1 also disclose a conveying device with a side channel blower, wherein the conveying device is at least partially driven by means of a metering valve with a jet of pressurized gaseous medium. Disclosure of the invention Advantages of the invention

[0008] According to the invention, a conveying device for a fuel cell system is proposed for conveying and / or recirculating a gaseous medium, in particular hydrogen, wherein the hydrogen is hereinafter referred to as H₂. The conveying device comprises a side-channel compressor, wherein the conveying device is at least partially driven by a metering valve with a motive jet of a pressurized gaseous medium, the pressurized gaseous medium being supplied to a compressor chamber of the side-channel compressor at least indirectly by means of the metering valve. The side-channel compressor comprises a housing with a compressor chamber located in the housing, which has a circumferential first side channel, and an impeller located in the housing which is rotatably arranged about an axis of rotation and is driven by a drive.Furthermore, the housing, particularly in the area of ​​the first side channel, has a gas inlet opening and a gas outlet opening, which are fluidically connected to each other via the compressor chamber. The gaseous medium can be, in particular, a motive fluid coming from a tank.

[0009] With reference to claim 1, the conveying device is designed such that the gaseous medium is supplied to the side-channel compressor via the impeller by means of the metering valve, wherein the supply occurs at least nearly in the direction of the axis of rotation on the side of the impeller facing away from the drive. This allows for a compact design of the conveying device, since the drive is arranged on the opposite side of the impeller from the metering valve in the direction of the axis of rotation.Furthermore, the component and / or assembly costs of the side channel blower can be reduced because the gaseous medium is no longer supplied from the drive side via the metering valve. This avoids the increased complexity of the components, such as a hollow shaft used to transmit torque from the drive to the impeller and to guide and supply the gaseous medium to the side channel blower. This results in cost savings for the entire conveying system. Additionally, the flow paths between the metering valve and the side channel blower can be shortened, reducing gaseous flow losses and thus increasing the overall efficiency of the conveying unit.

[0010] The measures listed in the dependent claims enable advantageous further developments of the conveying device specified in claim 1. The dependent claims relate to preferred further developments of the invention.

[0011] According to an advantageous embodiment of the conveying device, the gaseous medium is fed from the metering valve into the area of ​​an axial opening in the impeller, the axial opening being particularly disc-shaped and circumferential around the axis of rotation. In this way, the gaseous medium can be introduced directly from the metering valve into the impeller without the need for additional components, such as piping. This results in reduced material and assembly costs for the conveying device. Furthermore, no seal is required, for example, for a piping system and / or a mechanical interface between the metering valve, thus enabling a low-wear and friction-free method of supplying the gaseous medium to the impeller or side-channel blower. This offers the advantage of an increased service life for the conveying unit due to reduced frictional wear.

[0012] According to a particularly advantageous embodiment of the conveying device, the impeller forms a wall on its side facing away from the axis of rotation, wherein the impeller has at least one radial opening on its inner wall through which the impeller is driven by means of a motive medium or the motive jet, particularly in the area of ​​a second side channel. In this way, the efficiency of the conveying unit can be improved, since the impeller is driven efficiently by the motive medium or the motive jet, which flows out of the radial opening of the impeller and thus drives the impeller in one direction of rotation. The motive medium, which is particularly under high pressure and flows at high velocity from the radial opening, flows into the area of ​​the second side channel.The impeller is set into a rotational movement by means of a recoil drive, the recoil being caused in particular by the driving medium flowing from the at least one radial opening into the second side channel.

[0013] According to an advantageous embodiment, the impeller has radial channels, wherein the channels extend from the region of the axial opening to the second side channel and wherein the radial channels fluidically connect the axial opening and the second side channel. In this way, the advantage is achieved that a large portion of the pressure energy and kinetic energy of the gaseous medium or drive jet injected via the metering valve, in particular the drive medium, can be converted into rotational energy of the impeller, thereby reducing the flow losses of the drive jet with the second side channel and / or of the drive medium with a radial channel. Thus, the efficiency of the conveying device and / or the side channel compressor can be increased.

[0014] According to a particularly advantageous embodiment, the radial channels are designed as open troughs, with each trough opening towards the axis of rotation on the side facing away from the drive. This design offers the advantage that the open troughs connecting the axial opening with the second side channel can be integrated into the impeller using a simple manufacturing process. Furthermore, this inventive design of the conveying unit eliminates the need for a separate component, such as a disc or cover, thereby reducing material and / or component costs.

[0015] According to an advantageous embodiment, the radial channels are designed as closed channels, with each channel being closed by means of a separate cover such that the channels are limited by the cover on the side facing away from the drive in the direction of the axis of rotation. This achieves the advantage of a compact design for connecting the axial opening to the second side channel.

[0016] According to an advantageous further development of the conveying device, the motive medium is metered into the second side channel at least indirectly via the metering valve and / or flows into it, wherein the second side channel is at least almost completely fluidically separated from the first side channel and / or is only fluidically connected in the region of the gas outlet opening. In this way, it can be ensured that a large part of the kinetic energy of the motive medium and the motive jet is used to drive the impeller and that this kinetic energy is not at least partially lost due to flow losses and / or friction losses with a recirculated fluid located in the first side channel.Furthermore, a pressure and / or momentum exchange takes place between the driving medium and the medium in the second side channel, whereby the driving medium has a higher pressure and / or higher velocity compared to the medium in the second side channel. This allows the efficiency of the conveying device and / or the side channel compressor to be increased.

[0017] According to a particularly advantageous embodiment of the conveying device, the impeller, depending on the operating state of a fuel cell, is driven either by the drive, which can be designed as a drive motor, or at least indirectly by the drive jet from the radial channel, or by the elements simultaneously. In this way, the drive motor of the side channel compressor can be supported by the effect of the drive jet from the metering valve at high load points of the side channel compressor and / or the fuel cell and / or the fuel cell system, allowing the drive motor and / or the impeller to be designed more compactly, thereby reducing the required installation space and the cost of the entire conveying device.Furthermore, a better efficiency of the conveying device can be achieved, as the conveying device can operate more efficiently under the different operating conditions of the fuel cell system and / or the fuel cell.

[0018] According to an advantageous embodiment of the conveying device, the at least one radial channel runs in a helical shape from the inside of the impeller to the wall. This ensures that the motive fluid is accelerated as much as possible as it flows through the radial channel or open trough by the rotation of the impeller in combination with the helical shape. Furthermore, the motive jet can exit the impeller at least nearly parallel to a tangent of the inner wall or at a slight angle to it, thus reducing friction losses. Additionally, due to the longer length of the radial channel, the motive fluid is exposed to the centrifugal force from the rotating impeller for a longer period as it flows through, resulting in further increased acceleration and a higher inflow velocity of the motive fluid into the second lateral channel.In this way, the efficiency of the conveying system and / or the side channel blower can be increased.

[0019] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, within the scope specified by the claims, a multitude of modifications are possible that fall within the bounds of what is considered skilled in the art. Brief description of the drawing

[0020] The invention is described in more detail below with reference to the drawing.

[0021] It shows: Figure 1 is a schematic sectional view of a conveying device according to the invention with a recirculation blower; Figure 2 is a schematic sectional view of a part of the conveying device according to a first embodiment and a second embodiment with a metering valve and a side channel blower; Figure 3 is a Figur 2 Sectional view and / or top view of the conveying device, the side channel compressor and an impeller according to a first or a second embodiment, designated AA, Description of the exemplary embodiment

[0022] According to the representation Fig. 1 Figure 1 is a schematic sectional view of a conveying device 1 according to the invention with a side channel blower 2.

[0023] The side channel compressor 2 has an impeller 14 rotating in a housing 17, which is attached to a drive shaft 9 and is set in rotation by a drive 10, which can be designed as a drive motor 10.

[0024] In one exemplary embodiment, the impeller 14 can be mounted on the drive shaft 9. Alternatively, the drive motor 10 can be designed as an axial field motor 10, which does not require a drive shaft 9.

[0025] This is in Fig. 1 It has been shown that the conveying device 1 is suitable for a fuel cell system 31 for conveying and / or recirculating a gaseous medium, in particular hydrogen. The conveying device 1 has the side channel compressor 2, wherein the conveying device 1 is controlled by means of a metering valve 6 (shown in Fig. 2 ) with a propulsive jet 12 (shown in Fig. 2 ) of a pressurized gaseous medium can be at least partially driven.

[0026] The pressurized gaseous medium is supplied to the conveying device 1 by means of the metering valve 6, wherein the side channel compressor 2 has the impeller 14, which is rotatably arranged about a rotary axis 23. An anode outlet of a fuel cell 29 is fluidically connected to a gas inlet opening 20 of the conveying device 1. Furthermore, an anode inlet of the fuel cell 29 is fluidically connected to a gas outlet opening 22 of the conveying device 1.

[0027] An electric drive motor 10 serves as the rotary drive 10 for the impeller 14. The conveying device 1 also includes the housing 17. The housing 17 comprises an upper housing part 7 and a lower housing part 8, which are connected to each other. Furthermore, the impeller 14 can be mounted non-rotatably on the drive shaft 9 and is enclosed by the upper housing part 7 and the lower housing part 8. The impeller 14 also forms a conveying cell 28 that extends externally onto a hub disc. These conveying cells 28 of the impeller 14 rotate around the axis of rotation 23 within a rotating compressor chamber 30 of the housing 17. Furthermore, in Fig. 1 In the area of ​​the conveying cell 28, the cutaway contour of a respective blade 11 and / or blades 11 can be seen. These respective blades 11 can have a V-shaped contour, with the symmetrical V-shaped contour extending in the direction of the axis of rotation 23. Furthermore, the respective conveying cell 28 is bounded in the direction of rotation of the impeller 14 by two respective blades 11, with a number of the blades 11 arranged radially around the axis of rotation 23 on the impeller 14.

[0028] As in Fig. 1 As shown, the housing 17, in particular the upper housing part 7 and / or the lower housing part 8, has at least one circumferential side channel 19, 21 in the area of ​​the compressor chamber 30. The at least one side channel 19, 21 extends within the housing 17 in the direction of the axis of rotation 23 such that it runs axially or radially to the pumping cell 28 on one or both sides. The at least one side channel 19, 21 can extend circumferentially around the axis of rotation 23 in at least a partial area of ​​the housing 17, whereby an interrupter area 15 can be formed in the housing 17 in the partial area where the first side channel 19 is not formed (see Fig. 3 ).

[0029] In one possible embodiment, the drive shaft 9 is connected axially to the axis of rotation 23, at least by a cardan joint, to the drive motor 10. Furthermore, the at least one bearing 27 is located axially on the outer diameter of the drive shaft 9 in the area between the lower housing part 8 and the impeller 14.

[0030] Furthermore, the housing 17, in particular the lower housing part 8, forms the gas inlet opening 20 and the gas outlet opening 22. The gas inlet opening 20 and the gas outlet opening 22 are fluidically connected to each other, in particular via the first side channel 19.

[0031] In the first embodiment, a torque is transmitted from the drive motor 10 to the impeller 14 via the drive shaft 9. In an alternative embodiment, the drive motor 10 can be designed as an axial field motor 10, and thus drive the impeller 14 directly by means of a magnetic field, without the need to transmit a torque via the drive shaft 9. In this case, the impeller 14 is set into rotational motion, and the conveying cell 28 rotates around the axis of rotation 23 through the compressor chamber 30 in the housing 17 in a direction of rotation 24 (see figure). Fig. 3 ) of the impeller 14. A gaseous medium already present in the compressor chamber 30 is moved along with the conveying cell 28 and thereby conveyed and / or compressed. In addition, a movement of the gaseous medium, in particular a flow exchange, takes place between the conveying cell 28 and the first side channel 19. Furthermore, the side channel compressor 2 is connected to the fuel cell system 31 via the gas inlet opening 20 and the gas outlet opening 22, wherein the gaseous medium, which is in particular an unused recirculation medium from the fuel cell 29, enters the compressor chamber 30 of the side channel compressor 2 via the gas inlet opening 20 and / or is supplied to the side channel compressor 2 and / or is drawn in from the area upstream of the gas inlet opening 20.In this process, the gaseous medium, after passing through the conveying device 1 and / or the side channel compressor 2, is discharged via the gas outlet opening 22 of the side channel compressor 2 and flows, in particular, via the anode outlet into the fuel cell 29. Furthermore, the conveying device 1 and / or the side channel compressor 2 have a housing 17 with the gas inlet opening 20 and the gas outlet opening 22 formed on the housing 17, which are fluidically connected to each other via the compressor chamber 30, in particular via the at least one first side channel 19.

[0032] Fig. 2 shows a schematic sectional view of a part of the conveying device 1 according to a first embodiment with the metering valve 6, the side channel compressor 2 and the drive motor 10.

[0033] The conveying device 1 for conveying and / or recirculating a gaseous medium, in particular hydrogen, is shown with the side channel compressor 2. The conveying device 1 is at least partially driven by the motive jet 12 of a pressurized gaseous medium via the metering valve 6, wherein the pressurized gaseous medium is supplied to the conveying device 1 at least indirectly via the metering valve 6 and is present as the motive medium. According to a particularly advantageous embodiment of the conveying device 1, the at least one radial channel 3 runs orthogonally to the axis of rotation 23.In this way, the advantage can be achieved that a large part of the pressure energy and kinetic energy of the drive jet 12 injected via the metering valve 6, in particular of the drive medium, can be converted into rotational energy of the impeller 14, thereby reducing the flow losses of the drive jet 12 with the second side channel 21 and / or of the drive medium with the radial channel 3. Thus, the efficiency of the conveying device 1 and / or the side channel compressor 2 can be increased.

[0034] Furthermore, in Fig. 2 shown that the conveying device 1 has the compressor chamber 30 extending around the axis of rotation 23, which has at least one circumferential first side channel 19, with a in the housing 17 (shown in Fig. 1 The impeller 14 is rotatably arranged about the axis of rotation 23 and is driven by the drive 10. The compressor chamber 30 and the first side channel 19 extend at least approximately in an annular shape around the axis of rotation 23. The side channel compressor 2 has the impeller 14, which has blades 11 arranged around its circumference in the region of the compressor chamber 30. The impeller 14 is fluidically connected to the metering valve 6 or a tank 25 by means of at least one radial channel 3 opening into at least one radial opening 16. The motive medium is metered from the radial channel 3 into a second side channel 21 and / or flows into it, the second side channel 21 being at least almost completely fluidically separated from the first side channel 19 and / or fluidically connected only in the region of the gas outlet opening 22.

[0035] The gaseous medium is supplied to the side-channel compressor 2 via the impeller 14 by means of the metering valve 6. The supply also occurs at least nearly in the direction of the axis of rotation 23 on the side of the impeller 14 facing away from the drive 10, in particular via a nozzle 36 of the metering valve 6 which is connected to the tank 25 via an internal channel 18. The gaseous medium is supplied from the metering valve 6 into the area of ​​an axial opening 5 of the impeller 14, the axial opening 5 being, in particular, disc-shaped and circumferential around the axis of rotation 23.

[0036] Fig. 2 Furthermore, it shows that the radial channels 3 extend from the region of the axial opening 5 to the second side channel 21, and that the radial channels 3 fluidically connect the axial opening 5 and the second side channel 21. In this process, Fig. 2 A first embodiment of the conveying device 1 is shown above the axis of rotation 23 and a second embodiment of the conveying device 1 is shown below the axis of rotation 23. According to a first embodiment, the radial channels 3 of the conveying device 1 or of the impeller 14 of the side channel compressor 2 are designed as open channels 3a, wherein the respective channel 3a is open in the direction of the axis of rotation 23 on the side facing away from the drive 10.

[0037] According to a second embodiment, the radial channels 3 of the conveying device 1 are designed as closed channels 3b, wherein the channels 3b are closed by means of a separate cover 26 in such a way that they are limited in the direction of the axis of rotation 23 on the side facing away from the drive 10 by the cover 26.

[0038] Furthermore, in Fig. 2 It has been shown that the drive shaft 9 can be supported by means of at least one bearing 27, in particular in the housing 17 and / or on the drive motor 10. The drive shaft 9 and / or the impeller 14 and / or the at least one bearing 27 and / or the drive motor 10 are at least nearly rotationally symmetrical about the axis of rotation 23. The impeller 14 can be attached to the drive shaft 9 by means of a press fit. According to an advantageous embodiment of the conveying device 1, the at least one radial channel 3 can extend at an angle β to the axis of rotation 23. In this way, the flow characteristics of the drive jet 12 or the drive medium into the second side channel 21 can be improved, especially if the second side channel 21 has a flow cross-section inclined away from the first side channel 19.

[0039] In another exemplary embodiment of the conveying device 1, the two side channels 19, 21 are fluidically separated from each other only over a small portion, in particular less than 50% of the length of the compressor chamber 30 running in the direction of rotation 24. Thus, the two side channels 19, 21 are fluidically connected to each other in the remaining portion of the compressor chamber 30 upstream of the gas outlet opening 22, with this portion comprising at least 50% of the total length of the compressor chamber 30 circumferentially around the axis of rotation 23. In this way, improved mixing of the motive medium with the recirculated fluid can occur, thereby creating, in particular, a suction jet effect, as the motive medium, flowing at a higher velocity, encounters the recirculated fluid, which flows at a lower velocity in the compressor chamber 30.This involves a transfer of momentum, creating a suction jet effect, not unlike the effect in a jet pump.

[0040] In an exemplary embodiment of the conveying device 1, the elements metering valve 6 and side channel blower 2 with the drive motor 10 are located in the housing 17 of the conveying device 1, wherein, in particular, the flow contours of the metering valve 6 and the side channel blower 2 and the channels 3, 5 that connect these two elements 2, 6 are located. Thus, separate housings are not required for the elements side channel blower 2 and metering valve 6, but the common housing 17 can be used for all elements.

[0041] In Fig. 2 It is shown that the motive medium, which is particularly under high pressure, flows from the tank 25 into the inner channel 18 of a nozzle 36. The motive medium from the tank 25 is metered into the inner channel 18 via the metering valve 6. From the inner channel 18, the motive medium continues to flow in a direction at least nearly parallel to the axis of rotation 23 and is injected via a nozzle 36 of the metering valve 6 into the axial opening 5 of the impeller 14. The at least one radial channel 3 runs orthogonally to the axis of rotation 23. In this region of the axial opening 5, the gaseous medium, which is particularly a motive medium, is deflected such that it flows from the region of the axial opening 5 to the radial channel 3 at an angle β and / or at least nearly orthogonally to the axis of rotation 23, and enters it.The motive medium flows from the radial channel 3 through the respective radial opening 16 into the second side channel 21. The impeller 14 has at least one radial opening 16 on an inner wall 13, through which the impeller 14 is driven by the motive medium. The motive medium is metered into the second side channel 21 at least indirectly via the metering valve 6 and / or flows into it, the second side channel 21 being at least almost completely fluidically separated from the first side channel 19 and / or fluidically connected only in the region of the gas outlet opening 22.

[0042] Fig. 2 Figure 26 also shows that the separate cover 26 can be designed as a disk 26, which is connected to the impeller 14 by means of an assembly step. This cover 26 makes it possible to incorporate the complex structure of the at least one radial channel 3, which in particular extends spirally away from the axis of rotation 23 (shown in Figure 26). Fig. 3 ).

[0043] In Fig. 3 is one in Fig. 2 The section and / or top view, designated AA, of the conveying device 1, the side channel compressor 2, and the impeller 14 according to a first or second embodiment. The impeller 14 has blades 11 arranged around its circumference in the region of the compressor chamber 30. It is further shown that the housing 17 has the gas inlet opening 20 and the gas outlet opening 22, which are fluidically connected to each other via the compressor chamber 30, in particular via the at least one first side channel 19. The recirculated fluid is supplied to the compressor chamber 30 from the anode outlet of the fuel cell 29 via the gas inlet opening 20. The side channel compressor 2 conveys and / or compresses the recirculated fluid in the respective side channel 19. From there, the compressed recirculated fluid reaches the gas outlet opening 22 and from there returns to the fuel cell 29, in particular via the anode inlet.The interrupter section 15 is located between the gas inlet opening 20 and the gas outlet opening 22 to prevent a pressure drop and / or pressure equalization from the gas outlet opening 22 to the gas inlet opening 20, particularly in the direction of rotation 24. The interrupter section 15 extends at least partially around the axis of rotation 23 and interrupts the respective side channel 19, 21, at least fluidically.

[0044] Furthermore, the impeller 14 forms a wall 13 on its side facing away from the axis of rotation 23, wherein the impeller 14 has at least one radial opening 16 and / or a bore 4 on its inner wall 13, through which the impeller 14 is driven by means of a driving medium or the driving jet 12, particularly in the area of ​​the second side channel 21. The driving jet 12 runs at an angle α of at least nearly 0° to 60° to a tangent 32 of the inner wall 13.

[0045] Furthermore, it is shown that the radial channel 3 forms the bore 4 in the end region facing a compressor chamber 30, but in particular only over a part of its total length. The at least one radial channel 3 runs in a helical shape from the inside of the impeller 14 to the wall 13.

[0046] The motive jet 12 of the metering valve 6, which is in particular a motive medium, is introduced into the second side channel 21 at high pressure and high velocity. This exerts a force on the impeller 14 such that it is set in motion, in particular a rotational motion, and / or kept in motion due to the lever arm. The impeller 14 rotates in the direction of rotation 24. The hydrogen flowing from the tank 25, in particular a high-pressure tank 25, through the metering valve 6 into the side channel compressor 2, which has a lower temperature in the tank 25 than the operating temperature of the side channel compressor 2, can thus be used as incoming hydrogen, which is in particular a motive medium, to cool the side channel compressor 2. This reduces the probability of failure of the conveying device 1 due to overheating.

[0047] In Fig. 3 It is further shown that, depending on the operating state of the fuel cell 29, the impeller 14 is either driven by the drive motor 10, or at least indirectly by the motive jet 12 of the metering valve 6, or simultaneously driven by elements 6, 10, and 12. The flow energy contained in the hydrogen to be metered is used to drive the impeller 14 of the side-channel compressor 2. The motive jet 12 flows into the area of ​​the second side channel 21 and thus drives the impeller 14. The hydrogen is supplied axially to the impeller 14 and guided radially outwards, so that the motive jet 12 exits the impeller 14 in the circumferential direction, thereby generating a torque on the impeller 14. To prevent imbalance, the radial openings 16 and / or radial channels 3 are evenly distributed around the circumference.

[0048] In Fig. 3It is further shown that the conveying cell 28 is located between two adjacent blades 11. The blades 11 also have a symmetrical V-shaped contour, the symmetrical V-shaped contour extending in the direction of the axis of rotation 23 and the open side of the symmetrical V-shaped contour of the blades 11 oriented in the direction of rotation 24 of the impeller 14.

Claims

1. Conveying device (1) for a fuel-cell system (31) for conveying and / or recirculating a gaseous medium, in particular hydrogen, having a dosing valve (6), having a side-channel compressor (2), which has a housing (17) and a drive (10), having a compressor chamber (30), which extends in the housing (17) so as to run around an axis of rotation (23) and has at least one first side channel (19) that runs around, having an impeller (14), which is situated in the housing (17) and is arranged so as to be rotatable about the axis of rotation (23) and is driven by the drive (10), having a gas inlet opening (20), formed on the housing (17), and a gas outlet opening (22), which are connected fluidically to one another via the compressor chamber (30), in particular the first side channel (19), wherein, by means of the dosing valve (6), the conveying device (1) is driven at least partially by a motive jet (12) of a pressurized gaseous medium, wherein the pressurized gaseous medium is fed to the compressor chamber (30) at least indirectly by means of the dosing valve (6), and wherein the gaseous medium is fed by means of the dosing valve (6) to the side-channel compressor (2) via the impeller (14), characterized in that this feeding takes place at least almost in the direction of the axis of rotation (23) on that side of the impeller (14) which is directed away from the drive (10).

2. Conveying device (1) according to Claim 1, characterized in that the gaseous medium is fed from the dosing valve (6) into the region of an axial opening (5) of the impeller (14), wherein the axial opening (5) extends around the axis of rotation (23) in particular so as to run around in the form of a disc.

3. Conveying device (1) according to Claim 1 or 2, characterized in that the impeller (14) forms a wall (13) on its side directed away from the axis of rotation (23), wherein the impeller (14) has at least one radial opening (16) on its inner wall (13), via which radial opening the impeller (14) is driven by means of the motive jet (12) or motive medium, in particular in the region of a second side channel (21) of the compressor chamber (30).

4. Conveying device (1) according to Claim 3, characterized in that the impeller (14) has radial channels (3), wherein the channels (3) extend from the region of the radial opening (16) to the second side channel (21), and wherein the radial channels (3) fluidically connect the radial opening (16) and the second side channel (21).

5. Conveying device (1) according to Claim 4, characterized in that the radial channels (3) are in the form of open grooves (3a), wherein the respective groove (3a) is open on the side directed away from the drive (10) in the direction of the axis of rotation (23).

6. Conveying device (1) according to Claim 4, characterized in that the radial channels (3) are in the form of closed channels (3a), wherein the respective channels (3a) are closed by means of a separate cover (26) in such a way that the channels (3b) are limited by the cover (26) on the side directed away from the drive (10) in the direction of the axis of rotation (23).

7. Conveying device (1) according to one of the preceding claims, characterized in that the motive jet (12) or the motive medium, at least indirectly, is dosed via the dosing valve (6) into a second side channel (21) of the compressor chamber (30) and / or flows into it, wherein the second side channel (21) is at least almost completely separated fluidically from the first side channel (19) and / or is connected fluidically thereto only in the region of the gas outlet opening (22).

8. Conveying device (1) according to Claim 4, characterized in that the impeller (14), in particular according to operating state of a fuel cell (29), is driven by the drive (10), which is in particular in the form of a drive motor (10), or is driven at least indirectly by the motive jet (12) from the at least one radial channel (3) or is driven simultaneously by the elements (10, 12, 6).

9. Conveying device (1) according to Claim 4, characterized in that the at least one radial channel (3a, b) extends in a helical manner from the interior of the impeller (14) to the wall (13).

10. Use of the conveying device (1) according to one of Claims 1 to 9 in a fuel-cell system (31).