Delivery unit for a fuel cell system for delivering and / or controlling a gaseous medium, fuel cell system, method for producing a nozzle for the delivery unit
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- ROBERT BOSCH GMBH
- Filing Date
- 2024-06-12
- Publication Date
- 2026-05-20
AI Technical Summary
Current fuel cell delivery units experience high flow losses, friction losses, and pressure losses due to the abrupt deflection of hydrogen gas, leading to inefficiencies and increased production costs, particularly in the design of asymmetrical diffuser areas which complicate manufacturing.
A delivery unit with a jet pump and metering valve, featuring an asymmetrical nozzle with an internal channel aligned to the axis of symmetry, where the nozzle's asymmetrical outlet diffuser compensates for asymmetrical flow, allowing for a longer, less abrupt deflection path, reducing losses and enhancing flow efficiency by integrating deflection within the diffuser area.
This design reduces flow resistance and pressure losses, enabling hydrogen to flow into the fuel cell at higher speed and pressure, improving the efficiency of the delivery unit and the entire fuel cell system while simplifying manufacturing and reducing costs.
Smart Images
Figure EP2024066169_16012025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Title fabric cells- to Medium, fuel cell Procedure for
[0003] State of the art
[0004] The present invention relates to a delivery unit for a fuel cell system for delivering and / or controlling a gaseous medium, in particular hydrogen, which is intended in particular for use in vehicles with a fuel cell drive. Furthermore, the present invention relates to a fuel cell system and a method for producing a nozzle for the delivery unit.
[0005] In the future, gaseous fuels will play an increasingly important role in the automotive sector, alongside liquid fuels. Hydrogen gas flows must be controlled, particularly in fuel cell-powered vehicles. The gas flows are no longer controlled discontinuously, as with liquid fuel injection. Instead, the gas is drawn from at least one tank, particularly a high-pressure tank, and fed to the delivery unit via an inlet line of a medium-pressure line system. This delivery unit then feeds the gas to a fuel cell via a connecting line of a low-pressure line system.
[0006] DE 10 2014 221 506 A1 discloses a delivery unit for a fuel cell system for delivering a gaseous medium, in particular hydrogen, comprising a jet pump driven by a propellant jet of a pressurized gaseous medium and a metering valve. The delivery unit can be designed as a combined valve-jet pump arrangement and comprises the components of a first inlet, intake region, mixing tube, and a diffuser region, wherein the diffuser region is fluidly connected to an anode inlet of a fuel cell via an outlet manifold. Optionally, a connecting piece can be located between the outlet manifold and the anode inlet. By means of the delivery unit, a medium, in particular a propellant medium, can be discharged through the nozzle, which is then mixed with a recirculation medium. The flow of the propellant medium can be controlled by means of the metering valve.In order for the gaseous medium to flow into the anode inlet of the fuel cell after passing through the valve-jet pump assembly, a deflection must occur due to the arrangement of the valve-jet pump assembly on the fuel cell. This deflection occurs at least almost exclusively in the area of the outlet manifold in the delivery unit known from DE 10 2014 221 506 A1, with the deflection occurring at least almost at a right angle and / or at least almost 90° so that the gaseous medium can flow from the delivery unit into the fuel cell.
[0007] DE 10 2019 214 676 A1 discloses a delivery unit for a fuel cell system for delivering and / or controlling a gaseous medium, in particular hydrogen. The delivery unit comprises the jet pump driven by a propulsion jet of a pressurized gaseous medium and the metering valve, wherein an output of the delivery unit is fluidically connected to the anode inlet of a fuel cell. The jet pump has the intake region, the mixing tube and the diffuser region, wherein the diffuser region is at least indirectly fluidically connected to the anode inlet of the fuel cell and wherein the gaseous medium flows through the jet pump at least partially in a first flow direction that runs parallel to a first longitudinal axis of the mixing tube. A second longitudinal axis of the diffuser region runs at an angle to the first longitudinal axis of the mixing tube, in particular at an angle α.According to the invention, a first wall of the diffuser region extends at an angle γ to the first longitudinal axis, and a second wall of the diffuser region opposite the first wall extends at an angle β to the first longitudinal axis, with the first wall extending on the side of the diffuser region facing away from the anode inlet and the second wall extending on the side of the diffuser region facing the anode inlet. The walls extend at least almost entirely linearly and are inclined toward the anode inlet in a second flow direction. Thus, the diffuser region is inclined toward the fuel cell and the fuel cell inlet.
[0008] The delivery unit known from DE 10 2014 221 506 A1 can have certain disadvantages. Since the deflection of the gaseous medium in the region of the delivery unit occurs at least almost exclusively in the region of the outlet manifold, an at least almost right-angled deflection must occur exclusively in this region, in particular by at least almost 90°. The first flow direction of the mixing tube and / or the second flow direction of the diffuser region runs at least almost at right angles to a second flow path of the anode inlet of the fuel cell, wherein the second flow path in particular forms the inflow direction of the gaseous medium into the fuel cell.This leads to high flow losses and / or friction losses and / or pressure losses between the gaseous medium and the walls of the delivery unit, particularly in the area of the outlet manifold, due to the short length in the direction of the first longitudinal axis of the jet pump available to deflect the gaseous medium. Furthermore, the delivery unit shown in the prior art, particularly in the flow area of the outlet manifold, can cause turbulence and / or flow separation that are detrimental to the efficiency of the delivery unit and / or the fuel cell system. This reduces the efficiency of the delivery unit and / or the entire fuel cell system.
[0009] The delivery unit known from DE 10 2019 214 676 A1 can have certain disadvantages. An asymmetrical flow field is created in such a way that the gaseous medium in the diffuser region is at least partially deflected toward the anode inlet by tilting the diffuser region toward the anode inlet and / or extending at an angle toward the anode inlet. However, such a design of the diffuser region described in DE 10 2019 214 676 A1 is associated with increased manufacturing and / or machining costs for the internal flow contours of a base body of the jet pump, since in this case the internal flow contours of the jet pump are no longer at least nearly rotationally symmetrical about an axis of symmetry. Thus, the diffuser region can no longer be incorporated into the base body using a single process step.Furthermore, limited access to the mixing tube and / or intake area can lead to difficult and costly processing. This can lead to increased production costs for the delivery unit shown in the prior art document DE 10 2019 214 676 A1, which in turn increases the costs of the entire fuel cell system.
[0010] Disclosure of the invention
[0011] Advantages of the invention
[0012] According to the invention, a delivery unit for a fuel cell system is proposed for the delivery and / or recirculation of a gaseous medium, in particular hydrogen. The delivery unit comprises a jet pump driven by a propulsion jet of a pressurized gaseous medium and a metering valve. An outlet of the delivery unit is fluidically connected to an anode inlet of a fuel cell, wherein the jet pump has a base body and, in this base body, a nozzle is arranged between the metering valve and the jet pump. The nozzle has an internal channel running along an axis of symmetry, wherein the jet pump has an intake region, a mixing tube, and a diffuser region, and wherein the diffuser region is at least indirectly fluidically connected to the anode inlet of the fuel cell.The jet pump runs at least partially in the direction of a first flow direction V, which runs parallel to the axis of symmetry and is flowed through by the gaseous medium.
[0013] Referring to claim 1, the nozzle has an asymmetrical outlet diffuser in the region of its channel opening facing the intake area and / or the mixing tube. In this way, an asymmetrical flow within the jet pump can be compensated for, and improved flow behavior of the gaseous medium through the intake area can be achieved, in particular the interaction of a propellant medium emerging from the outlet diffuser and impinging on the recirculated material. Furthermore, highly asymmetrical inflow conditions, in particular a swirl flow in the intake area and / or mixing tube, can be compensated for. In this way, a deflection of the gaseous medium in the region of the delivery unit can be achieved in an advantageous manner, in particular over a longer flow path and / or by means of a smaller deflection on a flow path of a specific length.This can reduce flow losses and / or friction losses and / or pressure losses between the gaseous medium and the walls of the delivery unit, as the deflection is more fluidically favorable. This improves the efficiency of the delivery unit and / or a valve jet pump arrangement and / or the entire fuel cell system.
[0014] The measures listed in the subclaims enable advantageous further developments of the conveying unit specified in claim 1. The subclaims relate to preferred further developments of the invention.
[0015] According to an advantageous embodiment of the delivery unit, the asymmetrical outlet diffuser of the nozzle is designed such that the outlet diffuser forms a first depression wall on the side of an inner diameter of the channel facing away from the fuel cell, in particular in an end region of the channel, wherein the first depression wall runs at an angle β to the axis of symmetry. This achieves the advantage that the propellant coming from the inner channel of the nozzle flows into the intake region at an angle β, wherein the propellant entrains a recirculate located in the intake region, thus creating a jet pump effect based on a momentum transfer between the particles of the propellant medium and the recirculate.The mixed gaseous medium, consisting of the propellant and the recirculated material, now flows in a third flow direction VI at a resulting angle α away from the nozzle through the intake area, with the resulting gaseous medium flowing in an arc through the jet pump and undergoing a deflection, for example, in the area of the mixing tube. In the area of the mixing tube, the gaseous medium flows partially at least almost parallel to the axis of symmetry and, due to the deflection in the mixing tube, ultimately flows further in the area of the diffuser area in a vector directed toward the anode inlet and / or in a direction directed toward the anode inlet.In this way, the gaseous medium is deflected toward the anode inlet already in the diffuser region, so that the medium needs to be deflected less in the components downstream of the diffuser region, such as the outlet of the delivery unit, in order to flow into the anode inlet region of the fuel cell, flowing at least approximately in a fourth flow direction VII. This achieves the integration of a deflection region into the diffuser region, allowing a more compact design of the delivery unit. In addition, pressure losses and / or friction losses can be reduced by deflection in a downstream region of the diffuser region, thereby improving the efficiency of the delivery unit of the entire fuel cell system.In this way, the flow resistance of the delivery unit for the necessary and almost right-angled deflection of the gaseous medium can be reduced, whereby a jet pump effect of the delivery unit can be improved and the medium can flow into the fuel cell at a higher speed and / or a higher pressure and / or a higher mass flow.
[0016] According to a particularly advantageous embodiment of the delivery unit, the asymmetrical outlet diffuser of the nozzle is designed such that the outlet diffuser forms the first depression wall on the side of the inner diameter of the channel facing away from the anode inlet, in particular in the end region of the channel. The first depression wall runs at an angle 82 to the axis of symmetry. Furthermore, the outlet diffuser forms a second depression wall on the side of the inner diameter of the channel facing the anode inlet, in particular in the end region of the channel, wherein the second depression wall runs at an angle y to the axis of symmetry. This allows the advantage of achieving a one-sidedly deflected propulsion jet of the propulsion medium coming from the inner channel of the nozzle.The propellant medium flows into the intake area at an angle ß2, whereby the propellant medium entrains the recirculate located in the intake area and a jet pump effect occurs which is based on a momentum transfer between the particles of the propellant medium and the recirculate. The mixed gaseous medium, consisting of the propellant medium and the recirculate then flows in a third flow direction VI at a resulting angle θ2 away from the nozzle through the intake area, whereby the resulting gaseous medium flows in an arc through the jet pump and is deflected, for example, in the area of the mixing tube. In the area of the mixing tube, the gaseous medium flows partly at least almost parallel to the axis of symmetry and, due to the deflection in the mixing tube, finally flows further in the area of the diffuser area in a vector directed towards the anode inlet and / or in a direction facing the anode inlet.In this way, the gaseous medium is deflected toward the anode inlet already in the diffuser region, so that the medium needs to be deflected less in the components downstream of the diffuser region, such as the outlet of the delivery unit, in order to flow into the anode inlet region of the fuel cell, flowing at least approximately in a fourth flow direction VII. This achieves the integration of a deflection region into the diffuser region, allowing a more compact design of the delivery unit. In addition, pressure losses and / or friction losses can be reduced by deflection in the downstream region of the diffuser region, thereby improving the efficiency of the delivery unit of the entire fuel cell system.In this way, the flow resistance of the delivery unit for the necessary and almost right-angled deflection of the gaseous medium can be reduced, whereby a jet pump effect of the delivery unit can be improved and the medium can flow into the fuel cell at a higher speed and / or a higher pressure and / or a higher mass flow.
[0017] According to an advantageous embodiment of the delivery unit, the angle θ2 is at least greater than the angle γ, but a width b2 of the first depression wall corresponds at least to a width c1 of the second depression wall. In this way, the propellant medium can be deflected in the region of the outlet diffuser such that it flows away from the outlet opening of the inner channel at an angle β2. This has the advantage of allowing an improved flow of the gaseous medium in an arcuate manner through the jet pump, whereby losses of impulse energy, kinetic energy and pressure are almost eliminated or at least reduced. Thus, the efficiency of the delivery unit and / or the valve jet pump arrangement and / or the entire fuel cell system can be improved.
[0018] According to a particularly advantageous development of the delivery unit, the angle δ2 corresponds at least almost to the angle γ, although the width b2 of the first depression wall is greater than the width c1 of the second depression wall. In this way, the propellant medium can be deflected in the region of the outlet diffuser such that it flows away from the outlet opening of the inner channel at an angle β2. This has the advantage of improving the flow of the gaseous medium in an arcuate manner through the jet pump, whereby losses of impulse energy, kinetic energy, and pressure are almost completely avoided or at least reduced. This improves the efficiency of the delivery unit and / or the valve-jet pump arrangement and / or the entire fuel cell system.
[0019] According to a particularly advantageous development of the delivery unit, the axis of symmetry of the nozzle runs at least almost congruent with the longitudinal axis of the jet pump and thus of the mixing tube and the diffuser area. In this way, a compact design of the delivery unit can be achieved by arranging the nozzle with the metering valve and the jet pump in such a way that they are not very bulky. Furthermore, the advantage can be achieved that the propellant can flow into the intake area and towards the recirculate with high efficiency, thus creating a highly efficient jet pump effect. This improves the efficiency of the delivery unit and / or the valve-jet pump arrangement and / or the entire fuel cell system.
[0020] According to an advantageous embodiment of the delivery unit, the nozzle of the jet pump is at least partially integrated into the metering valve. This provides the advantage of achieving high efficiency in generating jet energy. Furthermore, a compact design of the delivery unit is possible, since the metering valve and nozzle are integrated into the jet pump, and the delivery unit requires less length in terms of installation space along the symmetry axis.
[0021] A method for manufacturing the nozzle with the asymmetrical outlet diffuser for the conveyor unit is also proposed. In a first step, a nozzle with the internal channel is provided. In a second step, a cutting and / or forming conical tool is moved into the end region of the channel in the direction of a machining axis, wherein the machining axis extends at an angle ß to the axis of symmetry. In a third step, a conical extension is formed, whereby a first countersink wall is formed exclusively on the side of the inner diameter of the channel facing away from the anode inlet.
[0022] Furthermore, a method for producing the nozzle with the asymmetrical outlet diffuser for the conveyor unit is proposed. In a first step, a nozzle with the internal channel is provided. In a second step, a cutting and / or forming conical tool is moved into the end region of the channel in the direction of a machining axis, wherein the machining axis is offset by an offset m1 and runs at least almost parallel to the axis of symmetry. In a third step, the conical widening is formed, with a first countersink wall forming on the side of the inner diameter of the channel facing away from the anode inlet and the second countersink wall forming on the side of the inner diameter of the channel facing towards the anode inlet.
[0023] The invention is not limited to the exemplary embodiments described here and the aspects highlighted therein. Rather, a multitude of modifications and / or combinations of the features and / or advantages described in the claims are possible within the scope of expert practice.
[0024] Short description of the drawing
[0025] The invention is described in more detail below with reference to the drawing.
[0026] It shows:
[0027] Figure 1 is a partially schematic sectional view of a fuel cell system with a feed unit and a fuel cell,
[0028] Figure 2 is a schematic sectional view of the delivery unit, in particular a nozzle and a metering valve, according to a first embodiment,
[0029] Figure 3 is a schematic sectional view of the delivery unit, in particular a nozzle and a metering valve, according to a second embodiment,
[0030] Figure 4 is a simplified representation of a flow chart to illustrate the claimed method according to a first embodiment,
[0031] Figure 5 is a simplified representation of a flow chart to illustrate the claimed method according to a second embodiment.
[0032] Embodiments of the invention
[0033] The illustration in Fig. 1 shows a schematic sectional view of a fuel cell system 31 with a delivery unit 1 and a fuel cell 29, wherein the delivery unit 1 has a combined valve-jet pump arrangement 8. The combined valve-jet pump arrangement 8 has a metering valve 6 and a jet pump 4, wherein the metering valve 6 is connected to the jet pump 4, in particular to a base body 13 of the jet pump 4, for example by means of a screw connection. The jet pump 4 has in its base body 13 a first inlet 28, a second inlet 36a, an intake region 7, a mixing tube 9, a diffuser region 11 and / or a connecting piece 26. The metering valve 6 has a second inlet 36b and a nozzle 12. The metering valve 6 is inserted into the jet pump 4, in particular into an opening in the base body 13 of the jet pump 4, in particular in the direction of a longitudinal axis 40, in particular of the mixing tube 9.
[0034] The fuel cell system 31 shown in Fig. 1 also includes the fuel cell component 29. The fuel cell 29 is at least indirectly fluidically connected to the valve jet pump arrangement 8 by means of an anode outlet 17 and / or an anode inlet 15. In this case, a propellant medium coming from a tank 34 flows in a first flow direction IV through the second inlet 36a, b into the metering valve 6. The propellant medium coming from the tank 34 is under high pressure, in particular of more than 6 bar, and / or it flows at a high speed, in particular at least almost the speed of sound, through an internal channel 14 of the nozzle 12. Furthermore, a recirculation medium coming from the fuel cell 29, which is in particular an unused recirculate, flows in the direction of a second flow direction V through the anode outlet 17 of the fuel cell 29 and then into the first inlet 28 of the delivery unit 1.From the first inlet 28, the recirculation medium reaches the intake area 7 of the jet pump 4. The second inlet 36a, b runs through the components base body 13 and / or metering valve 6. From the metering valve 6, the propellant is discharged by means of an actuator and a fully closable valve element, in particular intermittently, through the internal channel 14 of the nozzle 12 into the intake area 7 and / or the mixing tube 9. The hydrogen flowing through the nozzle 12 and serving as the propellant has a pressure difference to the recirculation medium, wherein the recirculation medium flows from the first inlet 28 into the delivery unit 1 and wherein the propellant medium has in particular a higher pressure of at least 6 bar.In order to achieve a so-called jet pump effect, the recirculation medium is conveyed at a low pressure and a low mass flow into a central flow region X of the delivery unit 1, for example by using a side channel compressor upstream of the delivery unit 1. The driving medium flows through the nozzle 12 into the central flow region X of the intake area 7 and / or the mixing tube 9 at the described pressure difference and at a high velocity, which can in particular be close to the speed of sound and thus below or above it. The driving medium then strikes the recirculation medium, which is already located in the central flow region of the intake area 7 and / or the mixing tube 9. Due to the high velocity and / or pressure difference between the driving medium and the recirculation medium, internal friction and turbulence are generated between the media.This creates a shear stress in the boundary layer between the fast-moving propellant medium and the much slower recirculation medium. This stress causes a momentum transfer, accelerating and entraining the recirculation medium. Mixing occurs according to the principle of conservation of momentum. The recirculation medium is accelerated in one flow direction, resulting in a pressure drop for the recirculation medium, which creates a suction effect and thus draws additional recirculation medium from the area of the first inlet 28. This effect can be referred to as the jet pump effect.
[0035] Furthermore, Fig. 1 shows that the gaseous medium, after flowing through the valve jet pump arrangement 8, flows back into the fuel cell 29 via the anode inlet 15 in a fourth flow direction VII. The first flow direction III and / or the second flow direction IV and / or the fourth flow direction VII run at least approximately parallel. Furthermore, the fuel cell 29 has an end plate 2, with the anode outlet 17 and the anode inlet 15 running through the end plate 2. The end plate 2 is located on the side of the fuel cell 29 facing the valve jet pump arrangement 8. The unused gaseous medium flows from the anode outlet 17 of the fuel cell 29, in particular a stack, in the second flow direction V through the end plate 2 into the first inlet 28 of the valve jet pump arrangement 8.From there, the gaseous medium flows into the intake area 7 and partially into the mixing tube 9 of the jet pump 4. An axis of symmetry 32 of the nozzle 12 runs at least almost congruent with the longitudinal axis 40 of the jet pump 4 and thus of the mixing tube 9 and the diffuser area 11. However, outlet diffuser 33 (shown in Fig. 2) of the inner channel 14 of the nozzle 12 runs asymmetrically to the respective axis of symmetry 32 and / or longitudinal axis 40, so that the propellant medium flows into the central flow region X as a propellant jet 20 at a resulting angle α. The mixed gaseous medium, consisting of the propellant medium and the recirculate, now flows in a third flow direction VI away from the nozzle 12 through the intake region 7, wherein the resulting gaseous medium flows in an arc through the jet pump 4 and undergoes a deflection, for example in the region of the mixing tube 9.
[0036] By controlling the metered addition of the propellant medium using the metering valve 6, the feed rate of the recirculation medium can be regulated and adapted to the respective needs of the entire fuel cell system 31 depending on the operating state and operating requirements. In an exemplary operating state of the feed unit 1 in which the metering valve 6 is closed, the propellant medium can be prevented from flowing from the second inlet 36 into the central flow area of the jet pump 4, so that the propellant medium cannot flow into the intake area 7 and / or the mixing tube 9 to the recirculation medium, thus interrupting the jet pump effect.
[0037] Furthermore, the jet pump 4 from Fig. 1 has technical features that further improve the jet pump effect and the conveying efficiency and / or further improve the cold start process and / or manufacturing and assembly costs. The diffuser region section 11 extends conically in the region of its inner flow cross-section. The nozzle 12 and the mixing tube 9 and / or the diffuser region 11 can run coaxially to one another. This shape of the diffuser region section 11 can produce the advantageous effect of converting the kinetic energy into pressure energy, whereby the possible conveying volume of the conveying unit 1 can be further increased, whereby more of the medium to be conveyed, in particular H2, can be supplied to the fuel cell 29, whereby the efficiency of the entire fuel cell system 31 can be increased.According to the invention, the metering valve 6 can be designed as a proportional valve 6 in order to enable an improved metering function and a more precise metering of the driving medium into the suction area 7 and / or the mixing tube 9.
[0038] Fig. 2 shows a schematic sectional view of the delivery unit 1, in particular of the nozzle 12 and the metering valve 6, according to a first exemplary embodiment. A portion of the inner flow contour of the nozzle 12 is shown. The nozzle 12 has the asymmetrical outlet diffuser 33 in the opening of the channel 14 facing the intake region 7 and / or the mixing tube 9. Furthermore, the asymmetrical outlet diffuser 33 of the nozzle 12 is designed such that the outlet diffuser 33 forms a first countersunk wall 37 on the side of an inner diameter 21 of the channel 14 facing away from the anode inlet 15. This first countersunk wall 37 is formed in an end region 23 of the channel 14, with the first countersunk wall 37 extending at an angle 51 to the axis of symmetry 32. The first countersink wall 37 extends over a width b1.The axis 38, which is in particular a machining axis 38, of the outlet diffuser 33 is slightly pivoted relative to the axis of symmetry 32 of the nozzle 12 and / or the metering valve 6, in particular by the angle ß. The outlet diffuser 33 is conical in shape, with the axis 38 being the cone axis 38.
[0039] Fig. 2 shows a particularly advantageous embodiment of the delivery unit 1 and / or the nozzle 12, in which the inner surface of the end region 23 of the inner channel 14 facing the fuel cell 29 and / or the anode inlet 15 remains at least unchanged and thus runs at least almost parallel to the axis of symmetry 32. A conical extension 35 is tilted by the angle ß such that the outer surface of the conical extension 35 falls onto the inner surface of the channel 14, at least on the side facing the fuel cell 29 and / or the anode inlet 15. The nozzle 12 of the jet pump 4 is at least partially integrated into the metering valve 6. The asymmetrical outlet diffuser 33 serves to compensate for an asymmetrical jet pump flow. The asymmetrical outlet diffuser 33 of the inner channel 14 of the nozzle 12 can be implemented easily and cost-effectively in production.In addition, this propulsion nozzle diffuser 33 is very small and can therefore be manufactured with little effort compared to the flow contours of the jet pump 4. The asymmetrical shape of the outlet diffuser 33 creates an asymmetry in the propulsion jet 20, which, if correctly aligned with the central flow region X and / or the axis of symmetry 32 of the jet pump 4, can compensate for the negative effects of the inflow and outflow, in particular the second flow direction V and / or the fourth flow direction VII. The delivery unit 1 and / or the nozzle 12 according to a first embodiment can be manufactured using a method 100 (shown in Fig. 4). A nozzle 12 is provided with the internal channel 14.In this case, a cutting and / or forming conical tool is moved into the end region 23 of the channel 14 in the direction of the machining axis 38, wherein the machining axis 38 runs at an angle ß to the axis of symmetry 32. In this case, the conical widening 35 of the outlet diffuser 33 is formed, wherein the first countersink wall 37 is formed exclusively on the side of the inner diameter 21 of the channel 14 facing away from the anode inlet 15.
[0040] Fig. 3 shows a schematic sectional view of the delivery unit 1, in particular the nozzle 12 and the metering valve 6, according to a second embodiment. The asymmetrical outlet diffuser 33 of the nozzle 12 is designed such that the outlet diffuser 33 forms the first countersunk wall 37 on the side of the inner diameter 21 of the channel 14 facing away from the fuel cell 29, in particular in the end region 23 of the channel 14. The first countersunk wall 37 runs at an angle δ2 to the axis of symmetry 32. In addition, the outlet diffuser 33 forms a second countersunk wall 39 on the side of the inner diameter 21 of the channel 14 facing the anode inlet 15, in particular in the end region 23 of the channel 14, the second countersunk wall 39 running at an angle γ to the axis of symmetry 32.In the delivery unit 1 and / or the nozzle 12 according to the second exemplary embodiment, the angle θ2 is at least greater than the angle γ, wherein, however, a width b2 of the first countersunk wall 37 corresponds at least to a width c1 of the second countersunk wall 39. The angle θ2 corresponds at least almost to the angle y, wherein, however, the width b2 of the first countersunk wall 37 is greater than the width c1 of the second countersunk wall 39. The axis 38, which is in particular the processing axis 38, of the outlet diffuser 33 is offset by an offset m1 relative to the axis of symmetry 32 of the nozzle 12 and / or the metering valve 6. The outlet diffuser 33 is conical, wherein the axis 38 is the cone axis 38. The delivery unit 1 and / or the nozzle 12 according to the second embodiment can be manufactured by means of a method 100 (shown in Fig. 5).A nozzle 12 is provided with an internal channel 14. A cutting and / or forming conical tool is moved into the end region 23 of the channel 14 in the direction of the machining axis 38, wherein the machining axis 38 is offset by the offset m1 and runs at least almost parallel to the axis of symmetry 32. The outlet diffuser 33 is conical, wherein the axis 38 is the cone axis 38. The conical extension 35 of the outlet diffuser 33 is formed, wherein the first countersunk wall 37 forms on the side of the inner diameter 21 of the channel 14 facing away from the anode inlet 15 and the second countersunk wall 39 forms on the side of the inner diameter 21 of the channel 14 facing towards the anode inlet 15.
[0041] Fig. 4 shows a simplified representation of a flow chart to illustrate the claimed method 100, which is represented in a highly simplified manner by rectangles 110 to 130 and arrows arranged therebetween. It shows how the multi-stage method for producing the nozzle 12 with the asymmetrical outlet diffuser 33 for the delivery unit 1 of the fuel cell system 31 can proceed. In a first method step 110, a nozzle 12 with an internal channel 14 is provided. In a second method step 120, a cutting and / or forming conical tool is moved 120 into the end region 23 of the channel 14 in the direction of the machining axis 38, wherein the machining axis 38 runs at an angle ß to the axis of symmetry 32.In a third method step 130, the conical extension 35 is formed, with the first countersunk wall 37 forming exclusively on the side of the inner diameter 21 of the channel 14 facing away from the anode inlet 15. The method 100 shown here serves to manufacture the nozzle 12 and / or the delivery unit 1 according to a first embodiment.
[0042] Fig. 5 shows a simplified representation of a flow chart to illustrate the claimed method 200, which is represented in a highly simplified manner by rectangles 210 to 230 and arrows arranged therebetween. It shows how the multi-stage method for producing the nozzle 12 with the asymmetrical outlet diffuser 33 for the delivery unit 1 of the fuel cell system 31 can proceed. In a first method step 210, a nozzle 12 with an internal channel 14 is provided. In a second method step 220, a cutting and / or forming conical tool is moved 120 into the end region 23 of the channel 14 in the direction of the machining axis 38, wherein the machining axis 38 is offset by the offset m1 and runs at least almost parallel to the axis of symmetry 32.In a third method step 230, the conical extension 35 is formed, with the first countersunk wall 37 forming on the side of the inner diameter 21 of the channel 14 facing away from the anode inlet 15, and the second countersunk wall 39 forming on the side of the inner diameter 21 of the channel 14 facing the anode inlet 15. The method 200 shown here serves to produce the nozzle 12 and / or the delivery unit 1 according to a second embodiment.
Claims
Claims 1. Delivery unit (1) for a fuel cell system (31) for delivering and / or controlling a gaseous medium, in particular hydrogen, comprising a jet pump (4) driven by a propulsion jet (20) of a pressurized gaseous medium and a metering valve (6), wherein an outlet (16) of the delivery unit (1) is fluidically connected to an anode inlet (15) of a fuel cell (29), wherein the jet pump (4) has a base body (13) and, in this base body (13), a nozzle (12) is arranged between the metering valve (6) and the jet pump (4), wherein the nozzle (12) has an internal channel (14) running along an axis of symmetry (32), wherein the jet pump (4) has an intake region (7), a mixing tube (9), and a diffuser region (20),wherein the diffuser region (20) is fluidically connected at least indirectly to the anode inlet (15) of the fuel cell (29), and wherein the jet pump (4) is directed at least partially in a first flow direction (V) which runs parallel to the axis of symmetry (32) and through which the gaseous medium flows, characterized in that the nozzle (12) has an asymmetrical outlet diffuser (33) in the region of its opening of the channel (14) facing the intake region (7) and / or the mixing tube (9).
2. Delivery unit (1) according to claim 1, characterized in that the asymmetrical outlet diffuser (33) of the nozzle (12) is designed such that the outlet diffuser (33) forms a first countersunk wall (37) on the side of an inner diameter (21) of the channel (14) facing away from the anode inlet (15), in particular in the end region (23) of the channel (14), wherein the first countersunk wall (37) runs at an angle (51) to the axis of symmetry (32).
3. Conveying unit (1) according to claim 1, characterized in that the asymmetrical outlet diffuser (33) of the nozzle (12) is designed such that the outlet diffuser (33) forms the first countersunk wall (37) on the side of the inner diameter (21) of the channel (14) facing away from the anode inlet (15), in particular in the End region (23) of the channel (14), wherein the first depression wall (37) runs at an angle (52) to the axis of symmetry (32) and that the outlet diffuser (33) forms a second depression wall (39) on a side of the inner diameter (21) of the channel (14) facing the anode inlet (15), in particular in the end region (23) of the channel (14), wherein the second depression wall (39) runs at an angle (y) to the axis of symmetry (32).
4. Conveying unit (1) according to claim 3, characterized in that the angle 52 is at least greater than the angle y, but a width b2 of the first countersunk wall (37) corresponds to at least a width c1 of the second countersunk wall (39) 5. Conveying unit (1) according to claim 3, characterized in that the angle 52 corresponds at least almost to the angle y, but the width b2 of the first countersunk wall (37) is greater than the width c1 of the second countersunk wall (39) 6. Delivery unit (1) according to one of the preceding claims, characterized in that the axis of symmetry (32) of the nozzle (12) is at least almost congruent with a longitudinal axis (40) of the jet pump (4) and thus of the mixing tube (9) and the diffuser region (11) 7. Delivery unit (1) according to one of the preceding claims, characterized in that the nozzle (12) of the jet pump (4) is at least partially integrated into the metering valve (6) 8. Fuel cell system (31) with a feed unit (1) according to one of the preceding claims, wherein the feed unit (1) is arranged in an anode circuit of the fuel cell system (31) 9. Method (100) for producing the nozzle (12) with the asymmetrical outlet diffuser (33) for the delivery unit (1) of a fuel cell system (31) according to one of the preceding claims, comprising the following steps: Providing (110) a nozzle (12) with an internal channel Moving (120) a cutting and / or forming conical tool into the end region (23) of the channel (14) in the direction of a machining axis (38), wherein the machining axis (38) extends at an angle ß to the axis of symmetry (32). Shaping (130) the conical extension (35), wherein the first countersink wall (37) is formed exclusively on the side of the inner diameter (21) of the channel (14) facing away from the anode inlet (15).
10. Method (200) for producing the nozzle (12) with the asymmetrical outlet diffuser (33) for the delivery unit (1) of a fuel cell system (31) according to one of the preceding claims, comprising the following steps: Providing (210) a nozzle (12) with an internal channel (14) Moving (220) a cutting and / or forming conical tool into the end region (23) of the channel (14) in the direction of a machining axis (38), wherein the machining axis (38) is offset by an offset m1 and runs at least almost parallel to the axis of symmetry (32). Forming (230) the conical extension (35), whereby the first countersunk wall (37) is formed on the side of the inner diameter (21) of the channel (14) facing away from the anode inlet (15) and the second countersunk wall (39) is formed on the side of the inner diameter (21) of the channel (14) facing the anode inlet (15),