Conveyor unit for conveying gaseous media in an anode circuit of a fuel cell system

Abstract

The invention relates to a conveyor assembly (3) for an anode circuit (9) of a fuel cell system (1) for conveying a gaseous medium, in particular hydrogen, from an anode region (38) of a fuel cell (2), wherein the conveyor assembly (3) comprises at least one recirculation blower (8), wherein the conveyor assembly (3) is at least indirectly fluidically connected to an outlet of the anode region (38) by means of at least one connecting line (23), and wherein the conveyor assembly (3) is fluidically connected to an inlet of the anode region (38) by means of a further connecting line (25). According to the invention, the conveyor assembly (3) has, in addition to the recirculation blower (8), a jet pump (4), a metering valve (6) and a separator (10) as further components, wherein the components (4, 6, 8, 10) are arranged at least almost completely in a common housing (7) for the flow profile of the gaseous medium.

Description

Technical Field

[0001] The invention relates to a conveyor assembly for an anode circuit of a fuel cell system for conveying a gaseous medium, in particular hydrogen, the conveyor assembly being particularly designed for use in a vehicle having a fuel cell drive. The invention also relates to a fuel cell system having such a conveyor assembly. Background Art

[0002] In the automotive sector, in addition to liquid fuels, gaseous fuels will also play an increasingly important role in the future. In particular, in vehicles with fuel cell drives, the hydrogen flow must be controlled. Here, the gas flow is no longer controlled discontinuously as with the injection of liquid fuels, but rather the gas is taken from at least one high-pressure tank and guided via an inlet line of a medium-pressure pipeline system to a conveyor unit. The conveyor unit guides the gas via a connecting line of a low-pressure pipeline system to the fuel cell.

[0003] DE 10 2011 105 710 B4 discloses a conveyor unit for a fuel cell system, which is used for conveying and / or recirculating a gaseous medium, the conveyor unit having a recirculation blower and a jet pump driven by a drive jet of a pressurized gaseous medium, wherein an anode output of the fuel cell is fluidically connected to an input of the conveyor unit, and wherein the output of the conveyor unit is fluidically connected to an anode input of the fuel cell.

[0004] DE 10 2014 105 995 A1 discloses a fuel cell system for conveying and / or recirculating a gaseous medium, wherein the gaseous medium under pressure is supplied to a jet pump by means of a metering valve.

[0005] The known conveyor assembly from DE 10 2011 105 710 B4 and the known fuel cell system from DE 10 2014 105 995 A1 may have certain disadvantages respectively. Here, the components of the conveyor assembly, in particular the recirculation blower and / or the jet pump and / or the metering valve, are at least partially connected to each other and / or to the fuel cell by means of a fluid connection device in the form of a pipeline and, if necessary, by means of an additional distributor plate with built-in channels. Here, these components exist at least partially as separate components, which are connected to each other by means of pipelines. Here, on the one hand, multiple flow deflections and therefore flow losses, in particular flow losses in all three dimensions of space, are generated. Thus, the efficiency of the conveyor assembly is reduced. In addition, the connection of the components of the conveyor assembly by pipelines is disadvantageous in this respect, that is, the pipelines may cause sealing problems during the service life of the conveyor assembly, in particular during strong temperature fluctuations, in particular in welded and / or welded pipelines. On the other hand, the disadvantage resulting from the arrangement of the individual components as at least partially separate assemblies is that these assemblies as a whole form a large surface with respect to the structural space and / or geometric volume. This facilitates rapid cooling of the components recirculation blower and / or injection pump and / or metering valve, especially when the entire vehicle is parked for a long time, which can lead to increased ice bridge formation and thus to increased damage to the components and / or the entire fuel cell system, which in turn can lead to reduced reliability and / or service life of the conveyor assembly and / or fuel cell system. Another disadvantage is the poor cold start behavior of the conveyor assembly and / or fuel cell system and / or the entire vehicle, since, especially at temperatures below 0° C., heating energy and / or thermal energy must be introduced separately into the components recirculation blower and / or injection pump and / or metering valve in order to eliminate possible ice bridges. Summary of the invention

[0006] According to the invention, a conveyor unit for a fuel cell system is proposed, which serves to convey and / or recirculate a gaseous medium, in particular hydrogen, wherein the hydrogen is referred to below as H 2 .

[0007] According to the present invention, the conveying unit is constructed in such a way that the conveying unit has a jet pump, a metering valve and a separator as other components in addition to the component recirculation blower, wherein the flow profile of the components for the gaseous medium is at least almost completely arranged in a common housing. In this way, the following advantages can be obtained: a direct and as short as possible flow line is established between the components of the conveying unit, in particular between the recirculation blower and / or the jet pump and / or the metering valve and / or the separator. In addition, the number of flow deflections and / or the change of the flow direction of the gaseous medium in the conveying unit can be reduced to the smallest possible number, because these components are positioned in a common housing and are therefore positioned relative to each other at a small distance. Here, the inlet opening and the outlet opening of the components recirculation blower and / or the jet pump and / or the metering valve and / or the separator are arranged relative to each other in a common housing so that the smallest possible length of the flow connection and the least possible flow deflection are generated between these components. Here, the flow profile is at least almost completely located in the common housing and external pipelines and / or external distributor plates can be at least almost completely omitted. As a result, on the one hand, leakages caused by leaky pipeline systems can be reduced, which reduces the probability of failure of the conveyor assembly and / or fuel cell system. On the other hand, friction losses and / or flow losses in the conveyor assembly and / or fuel cell system, especially caused by pipeline length and the number of deflections, can be reduced, thereby improving the efficiency of the conveyor assembly and / or fuel cell system.

[0008] Furthermore, by arranging the flow profiles of the components and / or the components at least almost completely in a common housing, it can be ensured in an advantageous manner that the entire surface of the conveying unit, which comprises in particular the components recirculation blower, jet pump, metering valve and separator, can be reduced in terms of the structural space and / or geometric volume. As a result, the advantage that can be achieved is that, in particular in the case of long parking times of the entire vehicle, rapid cooling of the components recirculation blower and / or jet pump and / or metering valve and / or separator is prevented, which leads to a reduction and / or avoidance of the formation of ice bridges. In this case, the effect that the components recirculation blower and / or jet pump and / or metering valve and / or separator generate heat during operation, for example by means of an electric actuator and / or by means of a magnetic actuator, can be used to avoid cooling of all components in the common housing is advantageously utilized. Furthermore, by arranging the components in a common housing, an improved cold start capability of the conveyor assembly and / or the fuel cell system can be achieved with an overall reduced volume of the conveyor assembly, in particular with long parking times of the entire vehicle, since less mass must be heated and since the existing heat of the individual components can be utilized to heat the common housing. In this case, the probability of failure of the conveyor assembly and / or the fuel cell system can also be reduced, wherein the service life can be increased. It is also advantageous that the separator does not have to be connected as an additional separate component in the anode circuit by means of external lines and / or an external distributor plate to the component recirculation blower and / or the jet pump and / or the metering valve.

[0009] Advantageous embodiments of the conveying device are given below.

[0010] According to an advantageous embodiment of the conveying unit, the recirculation blower has a compressor wheel with a surrounding outer limiting ring, which extends rotationally symmetrically with respect to the rotation axis of the compressor wheel, and wherein an at least partially enclosed separation chamber is located in the housing of the conveying unit on the side of the compressor wheel facing away from the rotation axis. In addition, the component H2O and / or the component N2 is separated from the gaseous medium in the recirculation blower, wherein the separation is carried out in the recirculation blower in particular by means of the centrifugal principle. In this way, on the one hand, the following advantages can be achieved: at least one side channel and / or the conveying unit is at least partially enclosed with respect to the outer area in the housing, in particular with respect to the separation chamber.

[0011] The efficiency of the recirculation blower and thus of the conveying unit can thus be improved. On the other hand, the following advantage can be achieved: heavy components can be discharged from the compressor chamber of the recirculation blower into the separation chamber, in particular between the outer limiting ring of the compressor wheel and the housing, and / or can be further discharged from the housing of the recirculation blower and the fuel cell system. This offers the following advantage: the increase in the efficiency of the recirculation blower and / or the fuel cell system can be maintained over the entire service life, because the proportion and / or concentration of H2 in the gaseous medium can be increased, while the proportion and / or concentration of heavy components, in particular H2O and / or N2 in the gaseous medium can be reduced. In addition, the following advantage is achieved: by conducting the heavy components out of the area of ​​the compressor chamber, the formation of so-called ice bridges between movable parts, in particular the compressor wheel and the housing, is prevented when the fuel cell system is shut down and at low ambient temperatures.

[0012] Such ice bridges make the start-up of the fuel cell system, in particular the recirculation blower, difficult or completely prevented. Therefore, the configuration of the recirculation blower according to the invention can prevent the rotating parts and / or the drive, in particular the electric drive, of the recirculation blower from being damaged by the formation of ice bridges. This leads to a higher reliability of the fuel cell system and / or the vehicle. By using the centrifugal principle to remove the heavy components, the following advantages can be achieved: the separation process is improved in such a way that the components H2O and N2 can be almost completely separated from the medium, in particular from H2. This can ensure that the highest possible proportion of H2 flows back to the fuel cell, which can increase the efficiency and / or power of the fuel cell on the one hand and only require a small amount of H2 to be supplied to the anode circuit from the outside on the other hand.

[0013] Furthermore, the following advantages can be achieved: In order to separate the components H2O and N2 from the component H2, no additional energy has to be provided and / or only a small amount of energy has to be provided, in particular from the fuel cell system and / or a higher-level system (vehicle). Therefore, it is no longer necessary to introduce further energy, in particular kinetic energy, into the medium, so that an optimal efficiency of the separation process can be achieved by means of the centrifugal principle by means of the recirculation blower. As a result, the efficiency of the fuel cell system can be increased and the operating costs can be reduced.

[0014] According to an advantageous extension of the conveying unit, the components H2O and / or N2 of the gaseous medium can be introduced from the recirculation blower into the separator by means of the centrifugal principle and / or the gravity principle and / or the pressure difference. In this way, the following advantages can be achieved: no additional components, such as pumps, are required to convey the components H2O and / or N2 from the recirculation blower into the separator. Only by means of the already existing centrifugal force and / or gravity and / or the increased pressure already present in the recirculation blower (especially for conveying the gaseous medium) can the synergistic effect be utilized to convey the components H2O and / or N2 from the recirculation blower into the separator. In addition, the separation process and / or other processes in the separator can be further improved and / or the efficiency can be increased by means of the introduced pressure and / or the energy from the recirculation blower. In this way, the efficiency of the recirculation blower and / or the separator and / or the entire fuel cell system can be improved.

[0015] According to a particularly advantageous extension of the conveying unit, the recirculation blower and the jet pump are arranged relative to each other in a common housing in such a way that the axis of rotation of the compressor wheel of the recirculation blower extends at least approximately perpendicularly to the longitudinal axis of the jet pump. In this way, the following advantages are achieved: flow losses and / or pressure losses in the conveying unit can be reduced due to the length of the flow line and / or the number of flow deflections. In addition, it is advantageous that the flow guides in the recirculation blower and the jet pump extend in parallel planes, wherein this advantageous effect can be improved in the following way, that is, the gaseous medium is advantageously introduced into the suction area of ​​the jet pump when it flows out of the recirculation blower (wherein the gaseous medium is loaded with eddy energy in particular in the recirculation blower), so that the pulse transmission and / or the jet pump effect can be improved in this area and / or in the area of ​​the mixing tube of the jet pump. In addition, the flow deflections of the gaseous medium are further reduced, thereby further reducing the flow losses in the conveying unit. As a result, the efficiency of the conveyor unit can be improved, especially at almost all operating points and / or pressure ratios of the fuel cell system, and the energy consumption for operating the conveyor unit can be reduced. In addition, the arrangement of the components recirculation blower and jet pump relative to one another can result in a compact design of the conveyor unit, so that the following advantages can be achieved: the conveyor unit requires little installation space, especially in the vehicle as a whole.

[0016] Furthermore, the configuration of the conveyor assembly according to the invention reduces the number of components required for assembling the conveyor assembly, which in turn leads to cost savings for the conveyor assembly. Furthermore, the probability of assembly errors due to incorrectly oriented components of the conveyor assembly relative to one another is reduced, which in turn reduces the probability of failure of the conveyor assembly during operation.

[0017] According to a particularly advantageous configuration of the conveying unit, the separator, in particular the collecting container of the separator, is at least indirectly connected to the compressor chamber and / or the separation chamber of the recirculation blower, wherein the connection is realized by means of a discharge channel extending at least approximately perpendicular to the axis of rotation. In this way, the following advantages can be achieved: the heavy components of the gaseous medium, in particular H2O and / or N2, can be directly discharged from the compressor chamber and / or the separation chamber of the recirculation blower into the collecting container without other components and / or external pipeline systems and / or external distributor plates being present between them. In this way, the flow losses between the collecting container of the separator and the compressor chamber and / or the separation chamber of the recirculation blower can be reduced. In addition, the required energy in the form of a pressure drop or the energy required for generating a mass flow for discharging the heavy components from the recirculation blower into the separator is reduced, because the flow losses can be reduced, and therefore, the pressure energy and / or acceleration energy already present from the recirculation blower is almost sufficient. In addition, it is advantageous that the connection is realized by means of a discharge channel extending approximately perpendicular to the axis of rotation. In this way, it can be ensured that the centrifugal force generated by the rotation of the compressor wheel, in particular also acting perpendicularly to the axis of rotation, can have the greatest effect and act with the best possible efficiency on the heavy components, in particular when these are discharged through the discharge channel. The efficiency of the conveying unit and / or the recirculation blower and / or the separator can thus be improved.

[0018] According to an advantageous embodiment, the outlet channel is provided at a low geodesic height during normal use. Arranged on the recirculation blower, in particular on the separation chamber. In addition, the outflow opening is arranged in the collecting container at a low geodesic height in conventional use. In this way, the following advantages can be achieved: gravity can be used to guide the heavy components out of the separation chamber and / or from the collecting container. Here, even when the pressure level in the separation chamber and / or the collecting container is reduced, it can be ensured that the heavy components are at least almost only guided from the component and therefore from the conveying unit and / or from the fuel cell system by means of gravity. In addition, it can be that in the arrangement of the outflow opening according to the invention, the collecting container of the separator can be at least almost completely emptied, and therefore the heavy components can be almost completely guided by means of the outflow opening arranged at a low geodesic height. Therefore, the separation degree of undesirable heavy components can be improved, thereby improving the efficiency of the recirculation blower and / or the separator and / or the fuel cell system.

[0019] According to a particularly advantageous extension, the collecting container has an outflow hole, wherein the discharge of H2O and / or N2 from the collecting container via the outflow hole can be controlled by means of a discharge valve. In addition, H2O can be discharged from the entire anode circuit only by means of the discharge valve. In addition, N2 and / or H2 can be discharged from the entire anode circuit only by means of the discharge valve. In this way, it is possible to control, according to the operating state of the fuel cell system and / or the conveying unit and / or the recirculation blower, when and how much of the medium present in the collecting container and / or in the entire anode circuit, especially heavy components such as H2O and / or N2, should be discharged by means of the discharge valve. Here, parameters that can be considered for the control of the discharge valve in the anode circuit and / or in the various components of the anode circuit, especially the collecting container, are, for example: temperature, pressure, the proportion of H2O and / or N2 in the gaseous medium, the operating state of the fuel cell, the speed of the recirculation blower, the volume flow, the mass flow. In this way, the efficiency of the fuel cell system and / or the delivery unit and / or the recirculation blower can be improved and the proportion of H2 separated from the anode circuit can be reduced, wherein the proportion of H2O and N2 separated from the anode circuit can be increased. In addition, the heavy components can be discharged in such a way that the operating state and / or driving situation of the entire vehicle can be taken into account.

[0020] Furthermore, the outlet valve can also fulfill the task of a purge valve, in which H 2 O and / or N 2 and / or H 2 are selectively discharged from the fuel cell system and / or the delivery unit and / or the recirculation blower.

[0021] According to an advantageous embodiment, the shut-off valve is located in the discharge channel, wherein the at least indirect fluid connection between the recirculation blower and the separator can be opened or closed by means of the shut-off valve. In this way, the following advantages can be achieved: by opening or closing the shut-off valve as required, a better discharge of the heavy components from the collecting container of the separator can be achieved. Here, on the one hand, the shut-off valve can be kept closed in order to prevent the gaseous medium from escaping from the recirculation blower through the discharge channel into the collecting container when the discharge valve is open, wherein in particular H2 is prevented from escaping. However, on the other hand, the shut-off valve can also be opened in such a way that the pressure and / or volume flow from the recirculation blower, in particular the separation chamber, can be used to better empty the heavy components and to better discharge the heavy components from the collecting container. In this way, the efficiency of the separator can be improved and / or the degree of separation of H2O and / or N2 relative to the gaseous medium and / or H2 can be increased, thereby improving the efficiency of the entire fuel cell system.

[0022] According to a particularly advantageous embodiment, the first sensor device and / or the second sensor device are connected to the control device, wherein in particular the first sensor device continuously senses a parameter of the separator and the second sensor device continuously senses a parameter of the recirculation blower, wherein the control device controls the opening and closing of the outlet valve and / or the shut-off valve, in particular based on the parameter sensed by the respective sensor device. In this way, the following advantages can be achieved: when a certain concentration of heavy components in the gaseous medium is determined by means of the sensor device and / or when certain pressure levels and / or temperature levels are determined and / or exceeded in different regions of the fuel cell system, in particular in the collecting container or the separation chamber, the heavy components can be removed as far as possible from the anode circuit and / or the separation chamber and / or the collecting container of the fuel cell system by means of the control, in particular opening and closing, of the outlet valve and / or the shut-off valve based on the data sensed by the sensor device. Furthermore, any pressure drop and / or flow and / or mass flow from the anode circuit, in particular the delivery unit and / or the recirculation blower and / or the first connecting line and / or the second connecting line, can be utilized in order to remove the heavy components from the anode circuit as efficiently as possible and at least with little additional energy consumption and / or to effect a corresponding separation. In this way, the efficiency of the fuel cell system can be increased.

[0023] The present invention is not limited to the embodiments described herein and the aspects emphasized therein. On the contrary, various modifications and / or combinations of the features and / or advantages described in the claims can be realized within the scope of the claims, which are within the scope of the processing of those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be described in detail below with reference to the accompanying drawings.

[0025] The accompanying drawings show:

[0026] Figure 1 Schematic diagram of a fuel cell system according to the invention with a conveyor assembly,

[0027] Figure 2 A perspective cutaway view of a conveyor unit with a recirculation blower, an ejector pump, a metering valve and a separator in one housing,

[0028] Figure 3: The conveying unit, especially the recirculation blower and the separator Figure 2 The three-dimensional cross-sectional view marked with AA in the figure,

[0029] Figure 4 The detail of the compressor chamber and / or separation chamber of the recirculation blower, which is marked with II in FIG. 3 ,

[0030] Figure 5 The part of the separator marked with III in FIG. 3,

[0031] Figure 6 Recirculation blower and separator with exhaust passage Figure 5 The part marked with IV. DETAILED DESCRIPTION

[0032] Figure 1 A schematic diagram of a fuel cell system 1 according to the invention is shown having a delivery unit 3 .

[0033] Here, in Figure 1 , the fuel cell system 1 comprises a fuel cell 2, wherein the fuel cell 2 comprises an anode region 38 and a cathode region 40. The anode region 38 of the fuel cell 2 is connected to an anode circuit 9, wherein the anode circuit 9 comprises a conveyor unit 3 and a tank 42.

[0034] Here, the anode region 38 is fluidically connected to the conveyor assembly 3 by means of a first connecting line 23, wherein the gaseous medium flows from the anode region 38 to the conveyor assembly 3 in a flow direction V. Here, in addition to the recirculation material flowing in from the anode region 38 of the fuel cell 2, the drive medium is supplied to the conveyor assembly from a tank 42. After flowing through the conveyor assembly 3, the gaseous medium consisting of the recirculation material and the drive medium flows back to the anode region 38 of the fuel cell in a flow direction V via a second connecting line 25.

[0035] The conveying unit 3 has a recirculation blower 8, a jet pump 4, a metering valve 6 and a separator 10. In this case, the recirculation blower 8 can be fluidically connected to the anode region 38 via a first connecting line 23 and / or to the separator 10 via a discharge channel 46 and / or to the jet pump 4 via a first inlet 28 in an exemplary embodiment. In addition, the jet pump 4 can be connected to the metering valve 6 via a second inlet 36. In this case, these connections can be implemented in particular as integrated in a common housing 7 (not shown here, see Figure 2) in the flow path in the anode loop 9. In addition, the metering valve 6 can be located between the box 42 and the jet pump 4. Here, the recirculation blower 8 of the conveying unit 3 conveys the unused recirculated material from the fuel cell 2 to the jet pump 4 via the first inlet 28. In addition, H2 under pressure (which is especially the driving medium) is supplied to the jet pump 4 along the flow direction VII by means of the metering valve 6 and flows into the jet pump 4 via the second inlet 36. In addition, the separation of the component H2O and / or the component N2 from the gaseous medium in the anode loop 9 is carried out by means of the recirculation blower 8 and / or by means of the separator 10. Here, H2O and / or N2 are discharged from the recirculation blower 8 into the separator 10, in particular into the collecting container 31 of the separator 10. In addition, there is an outlet valve 44 on the separator 10, by means of which the heavy components H2O and / or N2 separated from the gaseous medium can be guided out of the anode loop 9 and / or the fuel cell system 1. Furthermore, a shut-off valve 51 is located between the recirculation blower 8 and the separator 10 , in particular in the region of the outlet channel 46 .

[0036] In addition, Figure 1 , it is shown that the first sensor device 22 and / or the second sensor device 24 are connected to the control device 21, wherein in particular the first sensor device 22 continuously senses a parameter of the separator 10 and the second sensor device 24 continuously senses a parameter of the recirculation blower 8, wherein the control device 21 controls the opening and closing of the outlet valve 44 and / or the shut-off valve 51, in particular based on the parameters sensed by the sensor devices 22, 24. In this case, the sensed parameters can be, for example, pressure, temperature, volume flow, different components of the gaseous medium, such as the concentration of H2, H2O, N2 and / or dirt particles. In this case, the sensor devices 22, 24 can also be installed directly on the conveyor unit 3, for example. With the help of corresponding logic or calculation methods stored on the control device 21, for example in the form of a CPU with a storage unit, based on the sensed data, the valves 44, 51 can be controlled and / or opened and / or closed accordingly, so that the heavy components can be optimally discharged from the anode circuit 9 and / or the fuel cell system 1, wherein as much light component H2 as possible can be introduced back into the anode circuit 9 again.

[0037] Figure 2 The present invention shows a perspective sectional view of a conveyor unit 3. In addition to the component recirculation blower 8, the conveyor unit 3 has a jet pump 4, a metering valve 6 and a separator 10 as further components, wherein the flow profile of the components jet pump 4, metering valve 6, recirculation blower 8, separator 10 for the gaseous medium is at least almost completely arranged in a common housing 7.

[0038] Here, the recirculation blower 8 has a compressor wheel 12, wherein the compressor wheel 12 is rotatably supported in the housing 7 about a horizontally extending rotation axis 48. Here, a drive device 47, in particular an electric drive device, serves as a rotary drive for the compressor wheel 12 and a torque and / or a rotational movement are transmitted by the drive device 47 via, for example, a drive shaft. In addition, the housing 7 forms a gas inlet opening 14 (not shown here, see FIG. 3) and a gas outlet opening 16. Here, the gas inlet opening 14 and the gas outlet opening 16 are fluidically connected to each other, in particular via at least one side channel 19. In addition, the housing 7 has a surrounding first side channel 19a and / or a surrounding second side channel 19b in the region of the compressor chamber 30. Here, a plurality of conveying units extend in the compressor wheel 12 around the rotation axis 48 in the compressor chamber 30 of the housing 7, which almost completely surrounds the rotation axis 48. The drive device 47, which is in particular made of a heat-conducting material, can be heated in an advantageous manner, which is advantageous in particular during a cold start of the conveying unit 3 and / or the vehicle. Here, the drive 47 is heated and, for example, due to its thermal conductivity, the heat energy is transferred to the compressor wheel 12 and other components of the conveyor assembly 3 and / or to the housing 7. When the conveyor assembly 3 and / or the vehicle is shut down, especially for a long period of time and / or at low ambient temperatures below freezing, the liquid freezes and forms ice bridges. These ice bridges may cause damage to the conveyor assembly 3 and / or the fuel cell system 1 during startup and / or start-up and / or during operation. The ice bridges are melted by heating the drive 47, and the liquid changes from a solid state of aggregation to a liquid state of aggregation and can be discharged. Advantageously, the drive 47 is arranged here so that the heat introduction into the housing 7 is carried out as quickly and effectively as possible. Here, the special shaping of the integrated housing and the use of composite materials for the housing can also lead to better thermal conductivity. Alternatively, in an exemplary embodiment, the thermal effect from the fuel cell 2, especially the fuel cell stack, can be used to heat or cool the integrated housing 7. In addition, the actuator of the metering valve 6 can be used as a heat source and act similarly to the drive 47 in an advantageous manner.

[0039] Here, the compressor chamber 30 of the recirculation blower 8 is fluidically connected to the suction region 11 of the jet pump 4 via the gas outlet opening 16 and / or the first inlet 28. Here, the first inlet 28 is configured in such a way that it is configured as a flow channel 41 integrated into the housing 7, wherein the flow channel forms a bend 43. Here, the bend 43 is configured in such a flow-optimized manner that the friction losses between the gaseous medium and the integrated flow channel 41 can be kept as small as possible. In addition, the eddy energy and / or kinetic energy loaded by the gaseous medium due to passing through the compressor chamber 30 in the recirculation blower 8 can be kept as loss-free as possible at least almost when flowing through the bend 43 of the integrated flow channel 41. Therefore, a high efficiency of the conveying unit 3 can be achieved.

[0040] Here, the jet pump 4 has a suction region 11, a mixing tube 13 and a diffuser region 15 extending in a conical shape and an outlet elbow 17 on a flow direction VIII extending in particular along its longitudinal axis 50, wherein the outlet elbow is connected to a second connecting line 25. Here, a so-called jet pump effect occurs in the jet pump 4. For this purpose, a gaseous driving medium, in particular H2, flows into the metering valve 6 from the outside of the conveying unit 3, in particular from the box 42, through the second inlet 36. Now, by opening the metering valve 6, the driving medium is introduced into the suction region 11, in particular under high pressure. Here, the gaseous driving medium flows in the direction of the flow direction VIII. The H2 flowing from the second inlet 36 into the suction region 11 and used as the driving medium has a pressure difference with the recirculating medium flowing from the first inlet 28 into the suction region 11, wherein the driving medium is in particular under a higher pressure of at least 10 bar. In order to cause the jet pump effect, a recirculating medium with low pressure and low mass flow is delivered to the suction region 11 of the jet pump 4. Here, the driving medium with the described pressure difference and the high speed that is especially close to the speed of sound flows into the suction area 11 through the metering valve 6. Here, the driving medium acts on the recirculation medium that is already in the suction area 11. Due to the large speed and / or pressure difference between the driving medium and the recirculation medium, internal friction and turbulence are generated between the mediums. Here, shear stress is generated in the boundary layer between the fast driving medium and the significantly slower recirculation medium. This stress causes pulse transmission, wherein the recirculation medium is accelerated and carried. Mixing occurs according to the principle of conservation of momentum. Here, the recirculation medium is accelerated along the flow direction VI and also produces a pressure drop for the recirculation medium, whereby suction occurs and therefore other recirculation media are supplemented and delivered from the first inlet 28 and / or the area of ​​the recirculation blower. By changing and / or adjusting the opening duration and opening frequency of the metering valve 6, the delivery rate of the recirculation medium can be adjusted and the corresponding requirements of the entire fuel cell system 1 are matched according to the operating state and the operating requirements.

[0041] exist Figure 2 It is also shown that in the region of the diffuser region 15 and / or the outlet elbow 17, the low pressure sensor 45 is arranged in a space-saving and / or integrated manner in the housing 7, thereby requiring less installation space. It is also shown that the recirculation blower 8 and the jet pump 4 are arranged relative to one another in the common housing 7 such that the rotation axis 48 of the compressor wheel 12 of the recirculation blower 8 extends at least approximately perpendicularly to the longitudinal axis 50 of the jet pump 4.

[0042] FIG. 3 shows a perspective sectional view AA of a conveyor assembly 3 having a recirculation blower 8, a jet pump 4 and a metering valve 6. It is shown here that the conveyor assembly 3 has, in addition to the jet pump 4, a recirculation blower 8, a metering valve 6 and a separator 10 as further components, wherein the flow profiles of the components 4, 6, 8 for the gaseous medium and / or the components 4, 6, 8 are at least almost completely arranged in a common housing 7. In an exemplary embodiment, the housing can be designed in two, three or more parts. In this case, the individual parts are in particular made of the same material and / or have at least approximately the same coefficient of thermal expansion.

[0043] In addition, it is shown in FIG. 3 that the metering valve 6 has a medium pressure sensor 57, which in particular senses the pressure of the driving medium flowing from the tank 42 via the second inlet 36 into the metering valve 6. It is also shown that the recirculation blower 8 has a gas inlet opening 14 and a gas outlet opening 16 and a compressor wheel 12. Here, the compressor wheel 12 forms a conveying unit 20 between two impeller blades, wherein the conveying unit 20 has an outer limiting ring 39 on the side facing away from the rotation axis 48. Here, the separation chamber 34 is constructed between the housing 7 and the outer limiting ring 39 of the compressor wheel 12. The heavy components are separated and / or collected in the separation chamber, for example, by means of the centrifugal principle based on their large mass. It is also shown that the separator 10, in particular the collection container 31 of the separator 10, is at least indirectly connected to the compressor chamber 30 and / or the separation chamber 34 of the recirculation blower 8, wherein the connection is achieved by means of a discharge channel 46 extending at least approximately perpendicular to the rotation axis 48. The heavy components of the gaseous medium, for example H2O and / or N2, are introduced from the recirculation blower 8, in particular from the separation chamber 34, into the separator 10 and / or the collecting container 31 by means of the centrifugal principle and / or the gravity principle and / or the pressure difference. The collecting container 31 also has an outflow opening 52, wherein the discharge of H2O and / or N2 from the collecting container 31 via the outflow opening 52 can be controlled by means of the outlet valve 44. Here, the outflow opening 52 is closed at its end facing away from the collecting container 31 by means of a valve seat 53 of a closing element 54, wherein the outflow opening 52 and thus the outlet valve 44 are opened by means of an electric actuator 27. Here, the valve seat 53 is opened by the moving away movement of the closing element 54, wherein the closing element 54 is actuated by the actuator 27. Furthermore, the actuator 27 can be designed as an electromagnetic actuator 27. When the valve seat 53 is open and / or the outlet valve 44 is open, the gaseous medium, in particular the heavy components, flows further into the region of the connection 26 which serves as an attachment to a continued line which, for example, conveys the heavy components back into the cathode region 40 of the fuel cell 2. Alternatively, however, the heavy components can also be discharged into the surroundings.

[0044] 3 shows that the collecting container 31 located in the common housing 7 is closed by means of a closing screw 56, wherein, in order to better enclose the collecting container 31, a sealing element 55 is provided between the housing 7 and the closing screw 56. The use of the closing screw 56 provides advantages in terms of manufacturing technology and advantages in terms of manufacturing costs. In addition, in an exemplary embodiment, the low pressure sensor 45 and / or the medium pressure sensor 57 can be part of the first sensor component 22 and / or the second sensor component 24.

[0045] In an exemplary embodiment of the conveyor unit 3, H2O can be discharged from the entire anode loop 9 only by means of the discharge valve 44. In another exemplary embodiment of the conveyor unit 3, N2 and / or H2 can be discharged from the entire anode loop 9 only by means of the discharge valve 44. Therefore, it is not necessary to provide an additional drain valve and / or purge valve in the anode loop 9, thereby reducing the cost of the conveyor unit 3.

[0046] exist Figure 4 The compressor chamber 30 of the recirculation blower 8 with the compressor wheel 12 is shown in FIG. Figure 2The part marked with II in FIG. It is shown here that the compressor wheel 12 has a surrounding outer limiting ring 39, which extends rotationally symmetrically with respect to the rotation axis 48 of the compressor wheel 12. Here, in the housing 7 of the recirculation blower 8 and / or the conveying unit 3, there is a separation chamber 34 and / or an exhaust channel 46 that is at least partially, especially enclosed by at least one side channel 19, on the side of the compressor wheel 12 that faces away from the rotation axis 48. The compressor wheel 12 is shown here, which has at least one external surrounding ring 29a, b in the area of ​​the outer limiting ring 39. The outer ring 29a, b extends radially with respect to the rotation axis 48 and on the side of the outer limiting ring 39 that faces away from the rotation axis 48. Here, at least one external ring 29a, b is axially and / or radially in contact with the housing upper part and / or the housing lower part of the housing 7 and / or forms a small gap size with it, which gap size cannot be overcome by the gaseous medium at least approximately. By allowing a small gap size to be formed between the compressor wheel 12 with at least one externally disposed surrounding ring 29a, b and the housing 7, it is possible to achieve at least a partial encapsulation of the at least one side channel 19 with the separation chamber 34. The separation chamber 34 is constructed between the housing 7 and the outer limiting ring 39 at least partially around the axis of rotation 48. When the rotational speed of the compressor wheel 12 increases, the forces, in particular centrifugal forces and / or ejection forces, acting on the heavy components of the gaseous medium in the compressor chamber 30 are so great that the heavy components flow in the flow direction IX from the respective side channels 19a, b and / or the compressor chamber 30 through the corresponding ring 29a, b and the housing 7 into the separation chamber 34. As a result, the heavy components are discharged from the region of the at least one side channel 19 and the delivery unit 20 and are collected in the region of the separation chamber 34. As a result, the component H2O and / or the component N2 are separated from the gaseous medium in the recirculation blower 8, wherein the separation is carried out in the recirculation blower 8 in particular by means of the centrifugal principle. These heavy components of the gaseous medium can be, for example, undesirable waste products and / or by-products, such as N2 and / or H2 and / or dirt particles, from the operation of the fuel cell system 1. By discharging the heavy components, the conveying and compression effect of the conveyor unit 3 can be increased, since the portion of the gaseous medium to be conveyed, in particular the H2 required for the current generation in the fuel cell 2, is increased in the conveyor unit 20 and the at least one side channel 19. The efficiency of the conveyor unit 3 can thereby be increased, since heavy components that are undesirable for the operation do not have to be conveyed together.

[0047] In addition, Figure 4 It is shown that the outlet channel 46 is arranged at a low geodesic height on the recirculation blower 8 , in particular on the separation chamber 34 , during normal use.

[0048] Figure 5A section of the separator 10 marked with III in FIG. 3 is shown. It is shown here that the separation chamber 34 is at least indirectly connected to the collecting container 31 of the separator 10 via the outlet channel 46. Here, the separation chamber 34 and / or the outlet channel 46 can form an increased pressure level relative to the collecting container 31 of the separator 10, and wherein H2O and / or N2 are discharged from the recirculation blower 8 into the separator 10 along the flow direction VI. Here, the outflow opening 52 is arranged at a low geodesic height in the collecting container 31 in conventional use. The heavy components of the gaseous medium collected in the collecting container 31 are discharged into the area outside the conveying unit 3 via the outflow opening 52. In order to open or close the outflow opening 52 and thus open or close the collecting container 31 of the separator 10, the actuator 27 is actuated, wherein the actuator 27 is part of the outlet valve 44.

[0049] exist Figure 6 , a shutoff valve 51 is shown in the outlet channel 46 , wherein an at least indirect fluid connection between the recirculation blower 8 , in particular the separation chamber 34 , and the separator 10 can be opened or closed, in particular by means of the shutoff valve 51 .

[0050] The invention is not limited to the embodiments described here and the aspects highlighted here. Instead, within the scope given by the claims, a number of variants are possible which are within the capabilities of a person skilled in the art.

Claims

1. A conveyor unit (3) for an anode circuit (9) of a fuel cell system (1) for conveying a gaseous medium from an anode region (38) of a fuel cell (2), wherein: The conveyor assembly (3) comprises at least one recirculation blower (8), wherein the conveyor assembly (3) is at least indirectly fluidically connected to the outlet of the anode region (38) by means of at least one connecting line (23), and wherein the conveyor assembly (3) is fluidically connected to the inlet of the anode region (38) by means of a further connecting line (25), wherein the conveyor assembly (3) has, in addition to the recirculation blower (8), a jet pump (4), a metering valve (6) and a separator (10) as further components, wherein the The components for the flow profile of the gaseous medium are arranged almost completely in a common housing (7), characterized in that the recirculation blower (8) has a compressor wheel (12) with a surrounding outer limiting ring (39) which extends rotationally symmetrically with respect to the rotation axis (48) of the compressor wheel (12), and wherein an at least partially enclosed separation chamber (34) is located in the housing (7) of the conveying unit (3) on the side of the compressor wheel (12) facing away from the rotation axis (48).

2. The conveyor unit (3) according to claim 1, characterized in that: The component H 2 O and / or the component N 2 is separated from the gaseous medium in the recirculation blower ( 8 ), wherein the separation takes place in the recirculation blower ( 8 ).

3. The conveyor unit (3) according to claim 2, characterized in that: The components H 2 O and / or N 2 of the gaseous medium are conducted from the recirculation blower ( 8 ) into the separator ( 10 ) by means of the centrifugal principle and / or the gravity principle and / or a pressure difference.

4. The conveyor unit (3) according to any one of claims 1 to 3, characterized in that: The recirculation blower (8) and the jet pump (4) are arranged relative to one another in the common housing (7) such that the rotation axis (48) of the compressor wheel (12) of the recirculation blower (8) extends approximately perpendicularly to the longitudinal axis (50) of the jet pump (4).

5. The conveyor unit (3) according to any one of claims 1 to 3, characterized in that: The separator (10) is at least indirectly fluidically connected to a compressor chamber (30) and / or the separation chamber (34) of the recirculation blower (8), wherein the connection is realized by means of an outlet channel (46) extending approximately perpendicularly to the rotation axis (48).

6. The conveyor unit (3) according to claim 5, characterized in that: The collecting container (31) of the separator (10) is at least indirectly fluidically connected to the compressor chamber (30) of the recirculation blower (8) and / or to the separation chamber (34).

7. The conveyor unit (3) according to claim 6, characterized in that: The discharge channel (46) is arranged at a low geodesic height above the recirculation blower (8) in normal use.

8. The conveyor assembly (3) according to claim 6, characterized in that: The collecting container (31) has an outflow opening (52), wherein the discharge of H2O and / or N2 from the collecting container (31) via the outflow opening (52) can be controlled by means of an outlet valve (44).

9. The conveyor unit (3) according to claim 8, characterized in that: The outflow opening (52) is arranged in the collecting container (31) at a geodesic height which is low in normal use.

10. The conveyor unit (3) according to claim 8, characterized in that: H2O is discharged from the entire anode circuit (9) only by means of the discharge valve (44).

11. The conveyor assembly (3) according to claim 8, characterized in that: Only by means of the outlet valve (44) can N2 and / or H2 be discharged from the entire anode circuit (9).

12. The conveyor unit (3) according to claim 8, characterized in that: A shut-off valve (51) is located in the outlet channel (46), wherein an at least indirect fluid connection between the recirculation blower (8) and the separator (10) can be opened or closed by means of the shut-off valve (51).

13. The conveyor unit (3) according to claim 12, characterized in that: A first sensor device (22) and / or a second sensor device (24) are connected to a control device (21), wherein the first sensor device (22) continuously senses a parameter of the separator (10) and the second sensor device (24) continuously senses a parameter of the recirculation blower (8), wherein the control device (21) controls the opening and closing of the discharge valve (44) and / or the shut-off valve (51).

14. The conveyor assembly (3) according to claim 1, characterized in that: The gaseous medium is hydrogen.

15. The conveyor assembly (3) according to claim 2, characterized in that: The separation is carried out in the recirculation blower (8) by means of the centrifugal principle.

16. The conveyor assembly (3) according to claim 7, characterized in that: The discharge channel (46) is arranged at a low geodesic height above the separation chamber (34) during normal use.

17. The conveyor assembly (3) according to claim 13, characterized in that: The control device (21) controls the opening and closing of the discharge valve (44) and / or the shut-off valve (51) based on the parameters sensed by the sensor devices (22, 24).

18. Use of a conveyor unit (3) for an anode circuit (9) of a fuel cell system (1) according to any one of claims 1 to 17, wherein the fuel cell system is used in a vehicle for supplying electrical energy to a driving device and / or auxiliary consumer devices.

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