阅读说明：本技术 用于燃料电池系统的用于输送和/或控制气态介质的输送机组 (Delivery unit for delivering and/or controlling a gaseous medium for a fuel cell system ) 是由 A·里希特 于 2020-03-11 设计创作，主要内容包括：本发明涉及一种用于燃料电池系统(31)的、用于输送和/或控制气态介质、尤其是氢气的输送机组(1),具有由处于压力下的气态介质的驱动射束驱动的喷射泵(4)和配量阀(6)；其中,输送机组(1)的输出端与燃料电池(29)的阳极输入端(15)流体连接；其中喷射泵(4)具有抽吸区域(7)、混合管(18)和扩散器(20)；其中扩散器(20)至少间接地与燃料电池(29)的阳极输入端(15)流体连接；并且其中,喷射泵(4)至少部分沿第一流动方向V的方向被气态介质流经,所述第一流动方向平行于混合管(18)的第一纵轴线(39)地延伸。根据本发明,扩散器(20)的第二纵轴线(40)在此对于混合管(18)的第一纵轴线(39)倾斜地延伸或弯曲地延伸。(The invention relates to a 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 pressurized driving jet of the gaseous medium and a metering valve (6); wherein the output of the conveyor assembly (1) is fluidly connected to the anode input (15) of the fuel cell (29); wherein the ejector pump (4) has a suction region (7), a mixing tube (18) and a diffuser (20); wherein the diffuser (20) is at least indirectly in fluid connection with the anode input (15) of the fuel cell (29); and wherein the jet pump (4) is flowed through by the gaseous medium at least partially in a first flow direction V, which extends parallel to a first longitudinal axis (39) of the mixing tube (18). According to the invention, the second longitudinal axis (40) of the diffuser (20) extends in this case obliquely or curvedly to the first longitudinal axis (39) of the mixing tube (18).)

1. A delivery unit (1) for a fuel cell system (31) for delivering and/or controlling a gaseous medium, in particular hydrogen, having an ejector pump (4) which is driven by a driving jet of the gaseous medium under pressure and having a metering valve (6), wherein an output of the delivery unit (1) is fluidically connected to an anode input (15) of a fuel cell (29), wherein the ejector pump (4) has a suction region (7), a mixing tube (18) and a diffuser (20), wherein the diffuser (20) is fluidically connected at least indirectly to the anode input (15) of the fuel cell (29), and wherein the ejector pump (4) is flowed through by the gaseous medium at least partially in the direction of a first flow direction V which runs parallel to a first longitudinal axis (39) of the mixing tube (18), characterized in that the second longitudinal axis (40) of the diffuser (20) extends obliquely or curvedly relative to the first longitudinal axis (39) of the mixing tube (18).

2. Conveyor assembly (1) according to claim 1, characterized in that a first wall (17) of the diffuser (20) extends at least partially parallel to a first longitudinal axis (39) of the mixing pipe (18) and a second wall (19) of the diffuser (20) opposite the first wall (17) extends at an angle (β) to the first longitudinal axis (39), wherein the first wall (17) extends on a side of the diffuser (20) facing away from the anode input (15) and the second wall (19) extends on a side of the diffuser (20) facing towards the anode input (15).

3. Conveyor assembly (1) according to claim 1, characterized in that a first wall (17) of the diffuser (20) has a curved trend (23) and a second wall (19) of the diffuser (20) opposite the first wall (17) has an at least almost linear trend and extends at an angle (β) with respect to a first longitudinal axis (39) of the mixing pipe (18).

4. Conveyor assembly (1) according to claim 2 or 3, characterized in that the second longitudinal axis (40) of the diffuser (20) is inclined in the direction of the anode input (15).

5. Conveyor assembly (1) according to claim 3, characterized in that the second longitudinal axis (40) of the diffuser (20) extends arcuately such that it extends at least almost parallel to the first longitudinal axis (39) of the mixing pipe (18) in a starting region of the diffuser (20) and at least almost perpendicular to the first longitudinal axis (39) of the mixing pipe (18) in an end region of the diffuser (20).

6. Conveyor assembly (1) according to one of the preceding claims, characterized in that a connection (26) and/or an outlet-bend (22) is located between the diffuser (20) and the anode input (15) of the fuel cell (29) and the connection and/or outlet-bend are at least indirectly in fluid connection with each other.

7. Conveyor assembly (1) according to claim 6, characterized in that a fourth longitudinal axis (44) of the connecting piece (26) extends parallel to a second flow path IV of the gaseous medium in the anode inlet (15), wherein the second longitudinal axis (40) of the diffuser (20) extends at least almost parallel to the fourth longitudinal axis (44) of the connecting piece (26) in the end region of the diffuser (20).

8. Conveyor assembly (1) according to one of the preceding claims, characterized in that the injection pump (4) has a heating element (11), wherein the injection pump (4) and/or the outlet bend (22) and/or the connection piece (26) are manufactured from a material or an alloy having a small specific heat capacity.

9. Conveyor assembly (1) according to one of the preceding claims, characterized in that it has as components an injection pump (4), a metering valve (6) and/or a side channel compressor (10) and/or a water separator (24), wherein these components are positioned on the end plates (2) of the fuel cells (29) such that a flow-through line extends between and/or within the components of the conveyor assembly (1) only parallel to the end plates (2), wherein the end plates (2) are arranged between the fuel cells (29) and the conveyor assembly (1).

10. A fuel cell system (31) with a conveyor assembly (1) according to any one of the preceding claims.

Technical Field

The invention relates to a delivery unit for a fuel cell system for delivering and/or controlling a gaseous medium, in particular hydrogen, which delivery unit is provided, in particular, for use in a vehicle having a fuel cell drive.

Background

In the field of vehicles, gaseous fuels, in addition to liquid fuels, are becoming increasingly important in the future. Hydrogen gas flow must be controlled especially in vehicles having fuel cell drives. In this case, the gas flow is no longer controlled discontinuously, as is the case when injecting liquid fuel, but rather the gaseous medium is removed from at least one tank, in particular a high-pressure tank, and is conducted to the conveyor assembly via the inflow line of the medium-pressure line system. The conveyor assembly directs the gas to the fuel cell through a connecting line of the low pressure piping system.

DE 102014221506 a1 discloses a supply assembly for a fuel cell system for supplying a gaseous medium, in particular hydrogen, comprising a jet pump driven by a pressurized drive jet of the gaseous medium and a metering valve. The feed unit can be designed as a combined valve-jet pump assembly and has a first component inlet, a suction region, a mixing tube and a diffuser, and the diffuser is fluidically connected to the anode inlet of the fuel cell via an outlet bend. Alternatively, the connection can be located between the outlet bend and the anode input. In this case, a medium, in particular a driving medium, can be sprayed through the nozzles by means of the conveyor assembly, which driving medium is then mixed with the recirculating medium. The drive medium flow can be controlled here by means of a metering valve. In order that the gaseous medium, after flowing through the valve-jet pump assembly, can flow into the anode input of the fuel cell, the deflection must be effected on the basis of the arrangement of the valve-jet pump assembly on the fuel cell. This deflection is effected at least almost exclusively in the region of the outlet bend by the conveyor assembly known from DE 102014221506 a1, wherein the deflection takes place at least almost at right angles and/or at least almost at 90 °, as a result of which the gaseous medium can flow out of the conveyor assembly into the fuel cell.

The conveyor assembly known from DE 102014221506 a1 may have certain disadvantages.

Since the deflection of the gaseous medium in the region of the conveyor assembly takes place at least almost exclusively in the region of the outlet bend, an at least almost right-angle deflection, in particular an at least almost 90 ° deflection, must take place only in this region. The first flow direction of the mixing tube and/or the second flow direction of the diffuser are at least approximately at right angles to a second flow path at the anode input of the fuel cell, wherein the second flow path in particular forms the inflow direction of the gaseous medium into the fuel cell. This results in high flow losses and/or friction losses and/or pressure losses between the gaseous medium and the walls of the conveyor assembly, in particular in the region of the outlet bend, due to the small length in the direction of the first longitudinal axis of the jet pump, which can be used to cause a deflection of the gaseous medium. Furthermore, in the case of the conveyor assemblies shown in the prior art, particularly in the flow region of the outlet bend, turbulence and/or flow separation which are detrimental to the efficiency of the conveyor assembly and/or the fuel cell system may occurThereby reducing the efficiency of the conveyor assembly and/or the overall fuel cell system.

Disclosure of Invention

According to the invention, a supply unit for supplying and/or recycling a gaseous medium, in particular hydrogen, for a fuel cell system is proposed, wherein the hydrogen is designated in the following as H₂。

With reference to claim 1, the second longitudinal axis of the diffuser extends obliquely or curvedly with respect to the first longitudinal axis of the mixing tube. In this way the following advantages can be achieved: the deflection of the gaseous medium in the region of the conveyor assembly no longer occurs only in the region of the outlet bend, but rather such a deflection of at least part of the gaseous medium already occurs in the region of the diffuser, which reduces the deflectionThe angle of flow deflection required in the region of the outlet bend. In this way, a deflection of the gaseous medium in the region of the conveyor assembly, in particular of the diffuser and/or the outlet bend, can be achieved over a longer flow path and/or with a smaller deflection over a flow path having a specific length. In this case, flow losses and/or friction losses and/or pressure losses between the gaseous medium and the walls of the conveyor assembly can be reduced, since the deflection takes place more fluidically and the friction of the gaseous medium with the walls of the conveyor assembly is reduced. Furthermore, reduced disadvantageous turbulence and/or flow separations occur in the region of the connection of the conveyor assembly and/or the anode input of the fuel cell, since the deflection occurs more uniformly and in the region of the diffuser in conjunction with the increased diameter, as a result of which disadvantageous flow changes, for example, due to locally strong flow rate changes, can be avoided. The flow rate of the gaseous medium in the diffuser is reduced here, while the medium simultaneously undergoes deflection, as a result of which improved inflow properties into the fuel cell can be brought about. In this way the following advantages can be achieved: losses of pulse energy, kinetic energy and pressure are almost avoided or at least reduced. Furthermore, the media to be transported, in particular H, can be realized on the basis of an improved deflection₂As little friction as possible is present between the conveyor assembly, in particular the diffuser and the flow-through geometry surfaces of the end regions of the outlet bends. Furthermore, pressure and/or friction losses which may occur as a result of flow deflection and/or changes in the direction of movement of the gaseous medium caused by deflection in the outlet bend can be reduced. In this way, the efficiency of the conveyor assembly and/or the valve-jet pump assembly and/or the entire fuel cell system can be improved. Furthermore, the following advantages can be achieved by the configuration according to the invention of the conveyor assembly: given the overall length of the structure (e.g., due to the structural space available in the entire vehicle), a larger deflection radius can be achieved, as a result of which the flow energy losses in the conveyor assembly due to friction of the gaseous medium with the flow-through geometry surfaces can be further reduced. This offers the advantage of a compact design of the conveyor assembly and at the same time a high efficiency of the conveyor assembly.

Advantageous embodiments of the conveyor assembly specified in claim 1 can be achieved by the measures specified in the dependent claims. The dependent claims relate to preferred embodiments of the invention.

According to one advantageous embodiment of the conveyor assembly, a first wall of the diffuser extends at least partially parallel to the first longitudinal axis of the mixing pipe and a second wall of the diffuser opposite the first wall extends at an angle to the first longitudinal axis of the diffuser, wherein the first wall extends on a side of the diffuser facing away from the anode inlet and the second wall extends on a side of the diffuser facing the anode inlet. In this way, a diffuser can be formed which at the same time enables a deflection of the gaseous medium. The integration of the deflection region into the diffuser is thus achieved, which can result in a more compact design of the conveyor assembly. Furthermore, a simplified and less expensive production of the flow region can be achieved by the first wall running parallel to the mixing tube.

According to a particularly advantageous development, the first wall of the diffuser has a curved course and the second wall of the diffuser, which is opposite the first wall, has an at least almost linear course and extends at an angle to the first longitudinal axis of the mixing pipe. In this way, a continuously increasing deflection of the gaseous medium in the second flow direction can be achieved, wherein the second flow axis extends in particular in an arc. Due to the curved course of the second wall, flow losses and/or friction losses and/or pressure losses can be prevented, since, for example, in the case of a linear course of the second wall with a deflecting edge, eddies and/or flow separations can occur. The efficiency of the conveyor assembly and/or the entire fuel cell system can thus be increased. Furthermore, the configuration of the conveyor assembly according to the invention makes it possible to reduce the energy losses that can occur if the friction between the gaseous medium and the walls of the flow region increases. In this way, the operating costs of the conveyor assembly and/or the fuel cell system can be reduced, since higher efficiencies can be achieved.

According to a particularly advantageous embodiment of the conveyor assembly, the second longitudinal axis of the diffuser is inclined in the direction of the anode inlet. In this way the following advantages can be achieved: the angle of the third flow direction in the outlet bend can be reduced, since the gaseous medium is already deflected in the region of the diffuser at least partially in the inflow direction of the anode input. The flow resistance of the conveyor assembly, in particular mounted on the end plate of the fuel cell, is reduced by the required flow deflection of the gaseous medium in the conveyor assembly, since the gaseous medium is already deflected in the region experiencing a reduction in the flow velocity of the gaseous medium due to the inclined second longitudinal axis of the diffuser. Therefore, only a smaller deflection of the gaseous medium has to take place in the region of the outlet bend, since at least one partial deflection already takes place in the region of the diffuser in the same direction. The flow resistance of the supply unit can be reduced in this case for the necessary and almost right-angled deflection of the gaseous medium, as a result of which the ejector pump effect of the supply unit can be improved and the medium can flow into the fuel cell at a higher speed and/or at a higher pressure and/or with a greater mass flow.

According to an advantageous embodiment of the conveyor assembly, the second longitudinal axis of the diffuser extends in an arcuate manner such that it extends at least approximately parallel to the first longitudinal axis of the mixing pipe in the initial region of the diffuser and at least approximately perpendicular to the first longitudinal axis of the mixing pipe in the final region of the diffuser. In this way, on the one hand, a fluid-optimized deflection at least approximately at a right angle can be achieved, wherein the two flow directions run at least approximately orthogonally to one another. By avoiding an edge-like flow around and/or by the configuration according to the invention of the starting and end regions of the diffuser, a reduction in turbulence and flow separation can be achieved when the gaseous medium flows into and out of the diffuser, since in this region a sudden change in direction of the flow is prevented. As a result, pressure and friction losses can be reduced on the basis of the deflection and/or change in flow direction of the gaseous medium through the arcuately extending second longitudinal axis of the diffuser, as a result of which the efficiency of the delivery unit and/or the valve-jet pump assembly and/or the entire fuel cell system can be improved.

According to an advantageous embodiment of the conveyor assembly, the connection and/or the outlet bend is located between the diffuser and the fuel cellThe anode inputs of the cells are at least indirectly in fluid connection with each other and the connection and/or the outlet-elbow. Furthermore, a fourth longitudinal axis of the connecting piece can run parallel to the flow path IV of the gaseous medium in the anode inlet, wherein the second longitudinal axis of the diffuser runs at least almost parallel to the fourth longitudinal axis of the connecting piece in the end region of the diffuser. In this way, acceleration and/or deceleration of the gaseous medium can be prevented, which can occur with several deflections, for example, if an external line system is used between the conveyor assembly and the fuel cell, in particular the anode input. In this case, it is possible to prevent the gaseous medium from losing energy, which is lost by internal and external friction when flowing through the external pipe system with the deflector. In this way the following advantages can be achieved: losses of pulse energy, kinetic energy and pressure are almost avoided or at least reduced. In addition, in this way, in particular a flow-optimized embodiment based on the connection piece and/or the outlet bend, it is possible to achieve a flow optimization of the medium to be conveyed, in particular H₂As little friction as possible is present between the surface of the throughflow geometry of the conveyor unit. Furthermore, pressure losses and/or friction losses which may occur as a result of flow deflections and/or changes in the direction of movement of the gaseous medium by means of deflection sections in the external pipe system can be reduced. In this way, the efficiency of the conveyor assembly and/or the valve-jet pump assembly and/or the entire fuel cell system can be improved. Furthermore, the following advantages can be achieved in this way: the flow connection between the jet pump and the anode input can be implemented as short as possible and/or at least with little flow deflection. Thus, the efficiency of the conveyor assembly and thus of the entire fuel cell system can be increased on the basis of reduced friction losses. Furthermore, an improved cold start capability of the conveyor assembly can be achieved with the integration of the connecting piece into the jet pump base body, since the connecting piece cools down more slowly, in particular due to the higher mass, and therefore makes it difficult to form ice bridges in the throughflow cross section, in particular in the case of short downtimes (Standzeiten).

According to one advantageous embodiment of the conveyor assembly, the injection pump has a heating element, wherein the injection pump and/or the outlet bend and/or the connecting piece are made of a material or an alloy having a low specific heat capacity. In this way the following advantages can be achieved: rapid heating-up of the conveyor assembly according to the invention, in particular in the context of a cold start-up procedure, can be achieved. Before the conveyor assembly and/or the entire fuel cell system is operated at low temperature, the heating element is supplied with energy, in particular electrical energy, wherein the heating element converts this energy into heat and/or thermal energy. This process is advantageously supported by a low specific heat capacity of the other components of the conveyor assembly, with which thermal energy can be rapidly introduced into the entire conveyor assembly and the presence of ice bridges can be eliminated. The ice bridges present can be removed more quickly by a more rapid heating of the sub-components and the conveyor assembly, in particular by melting due to heat input. Furthermore, thermal energy can enter the nozzle during a cold start shortly after the heating element is switched on and can heat up and thus eliminate the ice bridge present in the region of the nozzle and the metering valve actuator. The probability of failure due to damage to conveyor assembly components can thereby be reduced. In this way, the cold start capability of the conveyor assembly and thus of the entire fuel cell system can be improved, since ice bridges can be melted and eliminated more rapidly. Furthermore, a small amount of energy, in particular electrical and/or thermal energy, must be introduced into the conveyor assembly via the heating elements used. This makes it possible to reduce the operating costs of the conveyor assembly and of the entire fuel cell system, in particular in the case of frequent cold start processes based on low ambient temperatures and/or long parking times of the vehicle. Furthermore, by using the material according to the invention, a high resistance to the medium to be transported by the conveyor assembly and/or to other components (e.g. chemicals) from the surroundings of the conveyor assembly can also be achieved. This in turn increases the lifetime of the conveyor assembly and can reduce the probability of failure due to damage to the housing material.

According to a particularly advantageous embodiment of the conveyor assembly, the conveyor assembly has as components an injection pump, a metering valve and/or a side channel compressor and/or a water separator. The conveyor assembly and/or the components thereof are positioned on the end plates of the fuel cells such that the flow lines extend between and/or within the components of the conveyor assembly only parallel to the end plates, wherein the end plates are arranged between the fuel cells and the conveyor assembly. In this way, a compact arrangement of the conveyor assembly on the fuel cell and/or in the fuel cell system can be achieved, as a result of which the space requirement and installation space of the fuel cell system in the entire vehicle can be reduced.

In addition, in this way a direct and as short as possible throughflow line between the delivery device assembly and the fuel cell assembly can be established. Furthermore, the number of flow deflections and/or changes in the direction of movement of the gaseous medium in the conveyor assembly can be reduced to as small an amount as possible. This provides the following advantages: the flow losses and/or pressure losses in the conveyor assembly due to the length of the throughflow lines and/or the amount of flow deflection can be reduced. It is also advantageous if the flow lines between and/or in the modules of the conveyor assembly run parallel to the plate-like support element. The flow deflection of the gaseous medium is thus further reduced, whereby the flow losses can be further reduced. This improves the efficiency of the conveyor assembly and reduces the energy consumption for operating the conveyor device. Furthermore, the following advantages can be achieved in this way: simple positioning of the components relative to one another can be achieved by: the modules must be connected to the end plates, respectively. This reduces the number of components required for assembly, which in turn leads to a cost saving of the conveying device. Furthermore, the probability of assembly errors due to components of the conveyor device that are misoriented relative to one another is reduced, which in turn reduces the probability of failure of the conveyor assembly during operation.

The present invention is not limited to the embodiments described herein and the aspects highlighted therein. But a plurality of variants and/or combinations of the features and/or advantages specified in the claims can be realized within the scope given by the claims, which variants and/or combinations are within the reach of a person skilled in the art.

Drawings

The present invention is explained in detail below with reference to the accompanying drawings.

The figures show:

FIG. 1 is a partial schematic cross-sectional view of a fuel cell system having a conveyor assembly and a fuel cell;

FIG. 2 is a schematic cross-sectional view of a conveyor assembly according to a first embodiment;

FIG. 3 is a schematic cross-sectional view of a conveyor assembly according to a second embodiment;

FIG. 4 is a schematic cross-sectional view of at least one cross-section A-A extending orthogonally to the flow direction according to a first embodiment;

fig. 5 is a schematic sectional view of at least one cross section a-a extending orthogonally to the flow direction according to a second embodiment.

Detailed Description

The illustration according to fig. 1 shows a schematic sectional illustration of a fuel cell system 31 with a conveyor assembly 1, wherein the conveyor assembly 1 has a combined valve-injection pump assembly 8. The combined valve-jet pump assembly 8 has a metering valve 6 and a jet pump 4, the metering valve 6 being 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 ejector pump 4 has a first inlet 28, a second inlet 36a, the suction region 7, the mixing pipe 18, the diffuser 20 and the outlet bend 22 and/or the connection piece 26 in its base body 13. The dosing valve 6 has a second inlet 36b and a nozzle 12. In particular, 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 the first longitudinal axis 39 of the mixing tube 18.

The fuel cell system 31 shown in fig. 1 also has the components fuel cell 29, water separator 24 and side channel compressor 10. The fuel cell 29 is in this case at least indirectly fluidically connected to the water separator 24 and/or the side channel compressor 10 and/or the valve-jet pump assembly 8 by means of the anode outlet 9 and/or the anode inlet 15. In this case, the recirculating medium flows out of the fuel cell 29 in the direction of the first flow path III via the anode outlet 9 and, in particular after flowing through the further optional components 10, 24 and/or the valve-jet pump assembly 8, flows back into the fuel cell 29 in the direction of the second flow path IV via the anode inlet 15. The first flow path III and the second flow path IV are at least approximately parallel here. In this case, the component water separator 24 and/or the side channel are compressedThe vessel 10 and/or the valve-jet pump assembly 8 are at least indirectly fluidly connected to each other. The components water separator 24 and side channel compressor 10 are optional components, which are not necessarily present in the feed unit 1 and/or in the fuel cell system 31. Furthermore, the fuel cell 29 has an end plate 2, wherein the anode output 9 and the anode input 15 extend through the end plate 2. Wherein the end plate 2 is located on the side of the fuel cell 29 facing the valve-jet pump assembly 8. The module ejector pump 4, the metering valve 6 and/or the side channel compressor 10 and/or the water separator 24 are positioned on the end plate 2 of the fuel cell 29 in such a way that the flow lines between and/or within the modules of the conveyor assembly 1 extend only parallel to the end plate 2, wherein the end plate 2 is arranged between the fuel cell 29 and the conveyor assembly 1. Here, the unconsumed gaseous medium flows from the fuel cells 29, in particular the anode outlet 9 of the stack, in the flow direction III through the end plate 2, via the optional water separator 24 and the optional side channel compressor 10 into the first inlet 28 of the valve-jet pump assembly 8. From there, the gaseous medium flows into the suction region 7 and partially into the mixing pipe 18 of the ejector pump 4. The water separator 24 has the following tasks: formed during operation of the fuel cell 29 and associated with a gaseous medium, in particular H₂The water that flows back into the valve-jet pump assembly 8 through the anode output 9 together is directed out of the system. Thus, water present in the gaseous and/or liquid state cannot enter the recirculation blower 10 and/or the ejector pump 4 and/or the metering valve 6, since it is already separated from the gaseous medium directly by the water separator 24 and is conveyed out of the fuel cell system 31. This prevents damage to components of the conveyor assembly 1 and/or the fuel cell system 31, in particular movable parts of the components, due to corrosion, thereby increasing the service life of all the components flowing past.

Fig. 1 also shows that the combined valve-jet pump assembly 8 is flowed through by the medium to be supplied in at least one flow direction V, VI, VII, VIII. The majority of the region of the valve-jet pump assembly 8 through which the fluid flows is designed at least approximately tubular and is used for conveying and/or guiding a gaseous medium, in particular H, in the conveyor assembly 1₂. In this case, on the one hand, the valve-jet pump group is fed via the first inlet 28The part 8 supplies a recirculation (rezirklatit), wherein the recirculation is in particular unconsumed H from the fuel cells 29, in particular the anode region of the stack₂Wherein the recycle may also have water and nitrogen. The recirculated material flows into the valve-jet pump assembly 8 via the first inlet 28. In another aspect, the gaseous driving medium, especially H₂Through a second inlet 36 outside the valve jet pump assembly 8, the drive medium flows into the recess of the valve jet pump assembly 8 and/or into the base body 13 and/or the metering valve 6, the drive medium coming from the tank 34 and being at a high pressure, in particular more than 6 bar.

In this case, the second inlet 36a, b extends through the component base 13 and/or the metering valve 6. The drive medium is conducted out of the metering valve 6 via the nozzle 12 into the suction region 7 and/or the mixing pipe 18 by means of the actuator and the completely closable valve element, in particular intermittently. H flowing through the nozzle 12 and serving as a driving medium₂A pressure difference with the recirculating medium is provided, wherein the recirculating medium flows from the first inlet 28 into the conveyor assembly 1, wherein the drive medium has in particular a higher pressure of at least 6 bar. In order to create the so-called jet pump effect, the recirculating medium is fed into the central flow region of the conveyor assembly 1 at a low pressure and low mass flow, for example by using a side channel compressor 10 upstream of the conveyor assembly 1. The drive medium flows here through the nozzle 12 into the suction region 7 and/or into the central flow region of the mixing tube 18 with the above-mentioned pressure difference and high velocity (which can in particular approach the speed of sound and therefore lie below or above the speed of sound).

The nozzle 12 has an inner groove in the form of a flow cross section through which the gaseous medium, in particular from the metering valve 6, can flow and flow into the suction region 7 and/or the mixing tube 18. Here, the drive medium encounters the recirculating medium which is already located in the suction region 7 and/or in the central flow region of the mixing tube 18. Due to the high velocity and/or pressure difference between the driving medium and the recirculating medium, internal friction and turbulence (turbulencen) are generated between the media. Here, shear stresses are formed in the boundary layer between the fast driving medium and the significantly slower recirculating medium. This stress causes a pulse transfer, wherein the recirculating medium is accelerated and carried along. This mixing occurs according to the law of conservation of momentum. In this case, the recirculating medium is accelerated in the flow direction V and a pressure drop is formed for the recirculating medium, as a result of which the suction effect is initiated and thus additional recirculating medium is additionally conveyed from the region of the first inlet 28. This effect may be referred to as a jet pump effect.

By actuating the feed metering of the drive medium by means of the metering valve 6, the delivery rate of the recirculated medium can be adjusted and the respective requirements of the entire fuel cell system 31 can be adapted to the operating state and operating requirements. In the exemplary operating state of the conveyor assembly 1 (in this case with the metering valve 6 in the closed state), a supplementary flow of the drive medium from the second inlet 36 into the central flow region of the ejector pump 4 can be prevented, so that the drive medium can no longer continue to flow in the flow direction VII into the suction region 7 and/or the mixing pipe 18 toward the recirculating medium, and the ejector pump effect is therefore interrupted.

Furthermore, the ejector pump 4 of fig. 1 has the following technical features, which additionally improve the ejector pump effect and the delivery effect and/or further improve the cold start process and/or the production and assembly costs. In this case, the subcomponent diffuser 20 extends conically in the region of its inner flow cross section, in particular increases in the first flow direction V and the second flow direction VI. The nozzle 12 and the mixing tube 18 and/or the diffuser 20 may extend coaxially relative to one another. This shaping of the subcomponent diffuser 20 can have the advantageous effect that the kinetic energy is converted into pressure energy, as a result of which the possible delivery volume of the conveyor assembly 1 can be further increased, as a result of which more medium to be delivered, in particular H, can be delivered₂Is supplied to the fuel cell 29, whereby the efficiency of the entire fuel cell system 31 can be improved.

As shown in fig. 1, the combined valve jet pump assembly 8 has an optional heating element 11, wherein the valve jet pump assembly 8 and/or the outlet bend 22 and/or the connecting piece 26 are produced from a material or alloy having a low specific heat capacity. In this way, the cold start capability can be improved, in particular at temperatures below 0 ℃, since the ice bridge present in the flow-through region of the valve-jet pump assembly 8 can thus be eliminated. The heating element 11 can be integrated in the base body 13 of the ejector pump 4 or arranged thereon.

According to the invention, the metering valve 6 can be embodied as a proportional valve 6, in order to be able to achieve an improved metering function and a more accurate metering of the drive medium into the suction region 7 and/or the mixing tube 18. In order to further improve the throughflow geometry and the efficiency of the conveyor assembly 1, the spray nozzles 12 and the mixing tube 18 are embodied rotationally symmetrically, wherein the spray nozzles 12 extend coaxially with the mixing tube 18 of the jet pump 4.

Fig. 2 shows a schematic sectional view of a conveyor assembly 1 according to a first exemplary embodiment. In this case, a part of the inner flow contour of the conveyor assembly 1, in particular of the main body 13, is shown, wherein this part has the following regions, in particular in the flow direction of the gaseous medium: suction zone 7, mixing pipe 18, diffuser 20, outlet-elbow 22 and connection 26. The mixing pipe 18, the diffuser 20, the outlet-elbow 22 and the connection piece 26 have respective longitudinal axes 39, 40, 42, 44. Along these respective longitudinal axes 39, 40, 42, 44, the respective flow directions V, VI, VII, VIII of the gaseous medium extend in this region.

It is shown here that the gaseous medium from the suction region 7 flows at least almost completely through the flow profile of the main body 13 up to the anode input 15 of the fuel cell 29, wherein the gaseous medium flows through the mixing tube 18, the diffuser 20, the outlet bend 22 and the connecting piece 26. In the suction region 7, the driving medium from the second inlet 36 is supplied by means of the nozzle 12 and encounters the recirculating medium supplied through the first inlet 28, which in particular comes from the fuel cell 29.

Furthermore, fig. 2 shows that the mixing tube 18 has a first longitudinal axis 39, wherein the first flow direction V extends at least approximately parallel to the first longitudinal axis 39. The diffuser 20 has a second longitudinal axis 40, wherein the second flow direction VI extends parallel to the second longitudinal axis 40. The outlet bend 22 has a third longitudinal axis 42, wherein the third flow direction VII extends parallel to the third longitudinal axis 42. The connection piece 26 has a fourth longitudinal axis 44, wherein the fourth flow direction VIII extends parallel to the fourth longitudinal axis 44. The longitudinal axes 39, 40, 42, 44 and/or the flow directions V, VI, VII, VIII in the respective region have different vectors and run non-parallel and/or in the same direction, so that the gaseous medium undergoes a deflection in the respective section 18, 20, 22, 26. The second longitudinal axis 40 of the diffuser 20 is embodied at an angle, in particular at an angle α, to the first longitudinal axis 39 of the mixing tube 18, the second longitudinal axis 40 of the diffuser 20 being inclined in the direction of the anode inlet 15. Furthermore, the third longitudinal axis 42 of the outlet bend 22 is inclined, in particular by an angle γ, relative to the first longitudinal axis 39 of the mixing tube 18, wherein the third longitudinal axis 42 of the outlet bend 22 is inclined in the direction of the anode inlet 15. Furthermore, the fourth longitudinal axis 44 of the connecting piece 26 is inclined, in particular at least approximately at a right angle, relative to the first longitudinal axis 39 of the mixing tube 18, wherein a fourth flow direction VIII running parallel to the fourth longitudinal axis 44 of the connecting piece 26 is directed toward the anode inlet 15.

Furthermore, fig. 2 shows that the first wall 17 of the diffuser 20 extends at least partially parallel to the first longitudinal axis 39 of the mixing pipe 18, and that the second wall 19 of the diffuser 20 opposite the first wall 17 extends at an angle β to the first longitudinal axis 39, wherein the first wall 17 extends on the side of the diffuser 20 facing away from the anode inlet 15, and the second wall 19 extends on the side of the diffuser 20 facing the anode inlet 15. The gaseous medium flows here in the region of the nozzle 12 and/or the mixing tube 18 in the first flow direction V and from there into the diffuser 20, wherein the gaseous medium undergoes a change of direction in the transition region of the mixing tube 18 to the diffuser 20, so that the gaseous medium flows at least almost in the second flow direction VI in the diffuser 20. Here, the angle β is greater than the angle α.

Fig. 2 shows that flow cross sections are formed in the inner flow region of the ejector pump 4, which flow cross sections extend in particular orthogonally to the respective flow directions V, VI, VII, VIII. In the region of the diffuser 20, the flow cross section is configured, for example, as at least one cross section a-a, wherein the at least one cross section a-a extends orthogonally to the second flow direction VI and/or the second longitudinal axis 40 of the diffuser 20. The cross section a-a increases in the second flow direction VI. Here, a reduction of the flow velocity of the gaseous medium can take place in the diffuser 20, in particular due to the increased cross section a-a. Furthermore, the second flow direction VI and/or the second longitudinal axis 40 extend at least almost linearly in the region of the diffuser 20 due to the at least almost linear trend of the first and second walls 17, 19, so that the gaseous medium also flows at least almost linearly in the region of the diffuser 20.

After flowing through the diffuser 20, the gaseous medium flows into the outlet bend 22 and from there into the connecting piece 26. In the region of the outlet bend 22, the third wall 21 extends on the side of the outlet bend 22 facing away from the anode input 15, which is shown in fig. 2. The third wall 21 may have an at least partially linear profile and/or may have a bend 23 at least in part, wherein the bend 23 may have a radius, in particular. The gaseous medium can be deflected by the third wall 21, in particular as a bend 23, toward the anode inlet 15 when flowing through the outlet bend 22. In this case, the third longitudinal axis 42 of the outlet bend 22 and/or the third flow direction VII of the gaseous medium extend in the region of the outlet bend 22 at an angle γ with respect to the first longitudinal axis 39 of the mixing tube 18 and are directed toward the anode inlet 15. In this case, angle γ is in particular greater than angle α and/or angle β.

As shown in fig. 2, the gaseous medium undergoes a corresponding deflection when flowing through the diffuser 20 and/or the outlet bend 22 and/or the connection 26, wherein the gaseous medium is deflected from a first flow direction V extending at least almost at right angles to the first flow path III and/or the second flow path IV towards a fourth flow direction VIII extending at least almost parallel to the respective flow path III, IV.

Fig. 3 shows a schematic cross-sectional view of a conveyor assembly 1 according to a second exemplary embodiment. Here, a part of the inner flow profile of the conveyor assembly 1, in particular of the base body 13, is shown, wherein this part has the following regions: suction zone 7, mixing tube 18, diffuser 20 and connection piece 26. The mixing tube 18, diffuser 20 and connector 26 have respective longitudinal axes 39, 40, 44. The respective flow directions V, VI and VIII of the gaseous medium extend in this region along the respective longitudinal axes 39, 40, 44. The second longitudinal axis 40 of the diffuser 20 extends in an arc-shaped manner, so that the gaseous medium is deflected, in particular continuously, when flowing through the diffuser 20 toward the anode inlet 15.

The arcuate profile of the second longitudinal axis 40 of the diffuser 20 is caused by the shaping of the walls 17, 19 of the flow field. The first wall 17 of the diffuser 20 has a curvature 23, and the second wall 19 of the diffuser 20 opposite the first wall 17 has an at least almost linear profile. The second wall 19 extends here at an angle β relative to the first longitudinal axis 39 of the mixing tube 18. In another exemplary embodiment, the second wall 19 may also have a curved portion. The angle α between the second longitudinal axis 40 of the curved extension and the first longitudinal axis 39 is thereby increased with continued flow through the diffuser 20 from a value of at least approximately 0 ° to a value of at least approximately 90 ° toward the anode input 15. The second longitudinal axis 40 of the diffuser 20 extends in an arcuate manner in such a way that it extends at least approximately parallel to the first longitudinal axis 39 of the mixing tube 18 in the initial region of the diffuser 20 and at least approximately perpendicular to the first longitudinal axis 39 of the mixing tube 18 in the final region of the diffuser 20, wherein in particular the opening of the final region of the diffuser 20 points toward the anode inlet 15.

Fig. 3 also shows that the fourth longitudinal axis 44 of the connection piece 26 extends parallel to the second flow path IV of the gaseous medium in the anode inlet 15, wherein the second longitudinal axis 40 of the diffuser 20 extends at least approximately parallel to the fourth longitudinal axis 44 of the connection piece 26 in the end region of the diffuser 20.

Fig. 3 also shows that flow cross sections are formed in the inner flow area of the ejector pump 4, which flow cross sections extend in particular orthogonally to the respective flow direction V, VI, VIII. In the region of the diffuser 20, the flow cross section is configured as at least one cross section a-a, wherein the at least one cross section a-a extends orthogonally to the second flow direction VI and/or to a second longitudinal axis 40 of the diffuser 20, which extends in particular in an arc-shaped manner. The cross section a-a increases in the second flow direction VI. Here, a reduction of the flow velocity of the gaseous medium can occur in the diffuser 20, in particular due to the increased cross section a-a. Furthermore, the second flow direction VI and/or the second longitudinal axis 40 extend at least almost arcuately in the region of the diffuser 20, in particular due to the curved course of the first wall 17 and/or the at least almost linear course of the second wall 19, so that the gaseous medium also flows at least almost arcuately in the region of the diffuser 20, in particular toward the anode inlet 15.

Fig. 4 shows a schematic sectional view of at least one cross section a-a extending orthogonally to the flow direction VI according to the first embodiment. The corresponding cross section a-a of the diffuser 20 has an at least almost circular shape. A first reference axis 48 extends through the first wall 17 and the second wall 19 of the flow cross section, which first wall extends away from the anode inlet 15, in particular at least in the initial region of the diffuser 20. The second reference axis 50 extends orthogonally to the first reference axis 48. The second longitudinal axis 40 extends in a plane not shown orthogonally to the two axes 48, 50 through the intersection of the two reference axes 48, 50.

Fig. 5 shows a schematic sectional view of at least one cross section a-a extending orthogonally to the flow direction VI according to a second embodiment. The respective cross section a-a has a circular, in particular elliptical and/or oval shape. A first reference axis 48 extends through the first wall 17 and the second wall 19 of the flow cross section, which first wall extends away from the anode inlet 15, in particular at least in the initial region of the diffuser 20. The second reference axis 50 extends orthogonally to the first reference axis of the oval cross section, so that it is located in the region of the greatest distance of the walls of the flow cross section. The second longitudinal axis 40 extends in a plane not shown orthogonally to the two axes 48, 50 through the intersection of the two reference axes 48, 50.

Alternatively, the cross-section of the outlet bend 22 and/or of the flow-through region of the connection piece 26 can also have a corresponding at least almost circular and/or elliptical shape.

The following advantages can be achieved with the first and second embodiments described in fig. 4 and 5: an improved deflection of the gaseous medium is achieved when flowing through the diffuser 20, wherein friction and/or flow losses are reduced, while the installation space required for the deflection of the gaseous medium to the anode input 15 can be reduced. The conveyor assembly 1 and/or the injection pump 4 can therefore also be installed in vehicles with only a small available installation space. The flow transition in the flow cross section of the ejector pump 4 is designed to be as flow-optimized as possible, so that a swirling of the gaseous medium and/or a deceleration of the flow rate is prevented.

In particular in the second embodiment of the at least one cross section a-a, a large part of the gaseous medium to be conveyed can flow through the diffuser 20 in the second flow direction VI in the region of the second reference axis 50 and thus undergo a stronger deflection toward the anode input 15, since the second reference axis 50 has a small distance from the second wall 19 and/or the anode input 15, which leads to improved flow characteristics and a more compact design, in particular compared to the first embodiment of the at least one cross section a-a. In addition, in this way, an improved flow guidance of the gaseous medium through the diffuser 20 and/or the entire conveyor assembly 1 can be achieved.

Furthermore, this shape of the cross section a shown in fig. 4 or 5 can be used in any combination of the regions diffuser 20, outlet bend 22, connection 26 and anode inlet 15 in the conveyor assembly 1 according to the invention, depending on the embodiment of the conveyor assembly 1 and/or of the jet pump 4, but can also be used in all other flow-through regions of the fuel cell system 31.