Fuel cell system and vehicle with a fuel cell system

Abstract

The technology disclosed herein relates to a fuel cell system (10) for a vehicle (100) comprising a main fuel cell stack (12) comprising at least one main process fluid channel (17) extending in a stacking direction (18) through the main fuel cell stack (12), at least one auxiliary fuel cell stack (13) comprising at least one auxiliary process fluid channel (19) extending in the stacking direction (18) through the auxiliary fuel cell stack (13), a control unit (14) for controlling a process fluid mass flow through the at least one main process fluid channel (17) and the at least one auxiliary process fluid channel (19), and a stack housing (16), wherein the main fuel cell stack (12), the at least one auxiliary fuel cell stack (13), and the control unit (14) are at least partially positioned in the stack housing (16).The technology also relates to a vehicle (100) with the fuel cell system (10).

Description

[0001] The technology disclosed here relates to a fuel cell system with a modular fuel cell stack and a vehicle with such a fuel cell system.

[0002] Fuel cell systems for vehicles are known in the art. In a vehicle, the fuel cell system is configured in particular to provide energy for at least one drive motor for propulsion of the vehicle. Generic fuel cell systems comprise a fuel cell stack. The fuel cell stack typically comprises a plurality of fuel cells, each having two electrodes and a membrane arrangement between the two electrodes. In the fuel cell stack, fuel can react with oxygen during reverse electrolysis, generating electricity. The fuel, for example hydrogen, can be supplied to the fuel cell stack from one or more high-pressure containers that are also installed in the vehicle. The oxygen is typically taken from the ambient air.

[0003] Depending on the vehicle's operating state, the fuel cell system generates more or less electricity. For the most efficient operation of the fuel cell system, it is desirable that the fuel cell system generates only a correspondingly small amount of electricity in vehicle operating states where little or no electricity is required.

[0004] The object of the present invention is to provide a fuel cell system and a vehicle with a fuel cell system by means of which the most efficient power generation possible is possible while at the same time operating the fuel cell system in a gentle manner.

[0005] The above object is achieved by the patent claims. In particular, the above object is achieved by the fuel cell system according to claim 1 and the vehicle according to the independent claim. Further advantages of the disclosed technology emerge from the dependent claims, the description, and the figures. Features described in connection with the fuel cell system also apply in connection with the vehicle, and vice versa, so that with regard to the disclosure of the individual aspects, reference is and / or can always be made to each other.

[0006] According to a first aspect of the present technology, a fuel cell system for a vehicle is proposed. The fuel cell system has a main fuel cell stack comprising a plurality of fuel cells and at least one main process fluid channel, wherein the main process fluid channel extends through the main fuel cell stack in a stacking direction. The fuel cell system further has at least one auxiliary fuel cell stack comprising a plurality of fuel cells and at least one auxiliary process fluid channel, wherein the auxiliary process fluid channel extends through the auxiliary fuel cell stack in the stacking direction. The fuel cell system also has a control unit for controlling a process fluid mass flow through the at least one main process fluid channel and the at least one auxiliary process fluid channel.The control unit can be set to an enable state, in which a process fluid connection is established between the at least one main process fluid channel and the at least one additional process fluid channel, and to a blocking state, in which a process fluid connection between the at least one main process fluid channel and the at least one additional process fluid channel is disconnected. The fuel cell system further comprises a stack housing, wherein the main fuel cell stack, the at least one additional fuel cell stack, and the control unit are at least partially positioned in the stack housing.

[0007] Accordingly, a modular fuel cell stack is provided whose stack modules can be easily functionally connected to and separated from one another using the control unit. If the control unit is or is set to the lock state, electricity can only be generated by the fuel cells in the main fuel cell stack. If the control unit is set to the enable state, electricity can be generated by the fuel cells in the main fuel cell stack and in at least one additional fuel cell stack. In this way, switching between different operating modes can be done easily and reliably. If an operating state is desired in which only a low maximum power or a correspondingly low maximum power generation is possible or desired, the control unit is set to the lock state.This operating mode can be selected to achieve low fuel consumption, whereby an excessive reduction in power below a predefined minimum power can be prevented. By reducing the number of active fuel cells, undesirable degradation of the fuel cells can also be prevented. If, however, the highest possible output power is desired or the generation of correspondingly high currents is desired, the control unit can be switched to the enable state. The number of usable fuel cells is then increased, whereby a correspondingly increased maximum output power can be achieved. The main fuel cell stack can be configured to cover a base load in the vehicle. The at least one additional fuel cell stack can be configured to meet a peak load requirement that is higher than the maximum base load.

[0008] The proposed fuel cell system can be implemented in a particularly compact manner, especially compared to solutions that use two or more separate and / or independent fuel cell stacks. Furthermore, the proposed fuel cell system can be implemented with a particularly simple process fluid channel structure. For example, a complex and space-intensive process fluid piping system, through which different stack modules must be supplied with process fluid separately, can be dispensed with. The integration of the control unit into the stack housing creates a significantly more compact and simpler system for the functional and / or process fluid-related separation and connection of the modular fuel cell stacks.

[0009] The main fuel cell stack and the at least one additional fuel cell stack can each be considered a stack module. In addition to the main fuel cell stack, the fuel cell system can have at least one additional additional fuel cell stack, for example, two, three, or even more additional fuel cell stacks. The main fuel cell stack can be understood as a first fuel cell stack, and the at least one additional fuel cell stack can be understood as a second, a third, and / or a further fuel cell stack, each fuel cell stack having a plurality of fuel cells. The main fuel cell stack and the at least one additional fuel cell stack can have the same number of fuel cells or a different number of fuel cells.

[0010] The fact that the main fuel cell stack and the at least one additional fuel cell stack are positioned in the stack housing can be understood to mean that the main fuel cell stack and the at least one additional fuel cell stack are positioned in a housing volume defined by the stack housing. The stack housing can be understood to mean a single stack housing in which the main fuel cell stack, the at least one additional fuel cell stack, and at least one part of the control unit are installed. The main fuel cell stack, the at least one additional fuel cell stack, and the control unit can be integrated into one another and / or configured as an integral unit.

[0011] The at least one main process fluid channel can be understood as the process fluid channels of a fuel cell stack that extend through the fuel cell stack in a stacking direction of the respective fuel cell stack. Thus, the at least one main process fluid channel can be understood as a fuel channel through the main fuel cell stack, an oxidizing gas channel through the main fuel cell stack, and a coolant channel through the main fuel cell stack. The respective channels can each be understood as an anode-side process fluid channel and / or a cathode-side process fluid channel. The at least one main process fluid channel can, for example, comprise a fuel channel, an oxidizing gas channel, and a coolant channel, each of which extends in the stacking direction as a process fluid supply channel and / or as a process fluid outlet channel of the main fuel cell stack.The same applies analogously to the at least one additional process fluid channel of the at least one additional fuel cell stack. The oxidation gas channel can be understood as a cathode gas channel leading to the individual fuel cells, as well as a cathode exhaust gas channel leading away from the individual fuel cells. The fuel gas channel can be understood as an anode gas channel leading to the individual fuel cells, as well as an anode exhaust gas channel leading away from the individual fuel cells. The coolant channel can be understood as a coolant channel that carries a coolant and / or a temperature control medium to the individual fuel cells for cooling and / or temperature control of the individual fuel cells. In the context of the present technology, a fluid can be understood as a gas, a gas mixture, and / or a liquid.

[0012] Accordingly, the control unit can, for example, be configured to establish or break a process fluid connection between the fuel channels, between the oxidation gas channels, and / or between the cooling fluid channels of the respective stack modules. The proposed solution is not limited to establishing and breaking a process fluid connection between the main fuel cell stack and the at least one additional fuel cell stack. For example, it is possible for the control unit to be configured to selectively establish or break a process fluid connection between two additional fuel cell stacks, while a process fluid connection between a main fuel cell stack and another additional fuel cell stack is established or broken by means of the control unit. The control unit can therefore be considered a single-piece or multi-piece component.In particular, the control unit can comprise several individual components that are positioned at a distance from one another, for example between the respective stack modules on the respective electrode sides.

[0013] The control unit can be understood as a unit for controlling and / or regulating the process fluid mass flow through the at least one main process fluid channel and the at least one additional process fluid channel. For this purpose, the control unit can be configured to change a flow cross-sectional area through the at least one main process fluid channel and / or through the at least one additional process fluid channel. For example, the flow cross-sectional area through the at least one main process fluid channel and / or through the at least one additional process fluid channel can be increased and / or decreased by means of the control unit.This means that the control unit can be configured to continuously increase the flow cross-sectional area directly within the at least one main process fluid channel, directly within the at least one additional process fluid channel and / or within a connecting channel, which can be configured between the at least one main process fluid channel and the at least one additional process fluid channel, up to a maximum flow cross-sectional area and / or to continuously reduce it down to the blocking state.

[0014] The control unit can be understood as a valve unit that has one valve or several spaced-apart valves for establishing the release state and the lock state. The control unit can be set and / or adjusted to the desired state by an actuator. The actuator can be controlled by a control unit. The control unit can be programmed such that the actuator is controlled depending on a predefined and / or predefinable operating state of the fuel cell system and / or the vehicle. Accordingly, the fuel cell system can be configured such that the control unit is set to the release state or the lock state depending on the predefined and / or predefinable operating state of the fuel cell system and / or the vehicle.The actuator system can be understood as an adjustment mechanism for adjusting a relative position of the control unit to the main fuel cell stack and / or to at least one additional fuel cell stack. The actuator system and the control unit can be understood as part of the fuel cell system.

[0015] The fuel cell system is preferably configured for mobile applications such as vehicles, in particular for providing energy for at least one drive unit, such as an electric motor, to propel the vehicle. In its simplest form, the fuel cell is an electrochemical energy converter that converts fuel and oxidant into reaction products, thereby producing electricity and heat. Each fuel cell may have an anode and a cathode separated from each other by an ion-selective or ion-permeable separator.

[0016] According to a further embodiment of the present technology, it is possible for the control unit to be positioned in the stacking direction between the main fuel cell stack and the at least one additional fuel cell stack. This means that the control unit or a part of the control unit can be positioned in the stacking direction in a sandwich-like and / or layer-like manner between the main fuel cell stack and the at least one additional fuel cell stack. It is also possible for the control unit or a further part of the control unit to be positioned between the additional fuel cell stack and another additional fuel cell stack in the same way.In this case, the various subsections of the control unit can be understood as a type of intermediate layer between the main fuel cell stack and the at least one additional fuel cell stack, as well as as intermediate layers between each two fuel cell stacks. Each intermediate layer or subsection of the control unit can be configured to control the process fluid mass flow between the respective fuel cell stacks or stack modules. The individual fuel cell stacks and the control unit(s) positioned between them can be installed one above the other in the stacking direction within the same stack housing. This allows for a compact yet simple design.

[0017] Furthermore, in the fuel cell system proposed here, it is possible for the control unit or at least a portion of the control unit to be displaceably positioned for setting the release state and for setting the lock state. In this way, the control unit can be particularly easily adjusted between the release state and the lock state. In this case, the control unit can be plate-shaped or substantially plate-shaped. The control unit and / or the portion of the control unit positioned between two fuel cell stacks can have at least two through-openings.The control unit and / or the subsection of the respective control unit can have a first through-opening for establishing a process fluid mass flow between the two fuel cell stacks on a process fluid supply side and a second through-opening for establishing a process fluid mass flow between the two fuel cell stacks on a process fluid outlet side. If the control unit or the subsection of the control unit is in the release state, the through-openings can be positioned directly adjacent to the respective process fluid channel.If the control unit or the partial section of the control unit has been moved into the blocking state, the through-openings are positioned at a distance from the respective process fluid channel, and a transition region from at least one main process fluid channel to at least one auxiliary process fluid channel is blocked by a wall region configured adjacent to the respective through-opening. A control unit as described above can have not only two, but also, for example, four or six through-openings. Thus, by moving the control unit or the partial section of the control unit, four or six spaced-apart process fluid mass flows can be established or interrupted simultaneously between the main fuel cell stack and the at least one additional fuel cell stack.

[0018] The fuel cell system proposed here may include a lever mechanism configured to set the enabled state and the disabled state using leverage. The lever mechanism allows the control unit to be switched between the enabled state and the disabled state in a simple yet reliable manner.

[0019] Furthermore, it is possible for the described fuel cell system to have at least one connecting channel between the at least one main process fluid channel and the at least one additional process fluid channel, with at least a part of the control unit being positioned in the connecting channel. In this way, the control unit or the at least one part of the control unit can be easily installed in the fuel cell system as a further modular component. In the event of a fault or damage, the at least one part of the control unit can be easily repaired or replaced. Alternatively or in addition to being positioned in the at least one connecting channel, the at least one part of the control unit can be positioned directly in the at least one main process fluid channel and / or directly in the at least one additional process fluid channel.The connecting channel is preferably configured directly between the main fuel cell stack and the at least one additional fuel cell stack and within the stack housing.

[0020] Furthermore, in the fuel cell system described here, it is possible for the control unit to have at least one membrane that is elastically deformable for setting the release state and the lock state. This membrane allows for a particularly space-saving solution. Furthermore, the membrane is relatively lightweight, which is particularly advantageous in mobile applications. Furthermore, the membrane allows for relatively simple, fluid-tight switching between the release state and the lock state.

[0021] In the fuel cell system proposed here, the at least one membrane can be tubular or each tubular in shape. A fastening ring can be provided on each of the two ends of the membrane, wherein a first fastening ring can be positioned on the at least one main process fluid channel and a second fastening ring can be positioned on the at least one additional process fluid channel. When adjusting the control unit to the blocking state, at least one of the fastening rings can be moved away from one of the process fluid channels, while the resulting opening on this process fluid channel can be simultaneously closed or sealed fluid-tight with a closure means of the control unit. Such an adjustment can be implemented, for example, by means of a lever mechanism as described above.

[0022] Furthermore, in a fuel cell system according to the described technology, it is possible for the control unit to have a valve body with at least one through-opening, wherein the valve body is rotatably positioned for setting the release state and for setting the blocking state. In this way, switching between the release state and the blocking state is particularly easy. The valve body can be mounted rotatably or rotatably about an axis of rotation. The axis of rotation can extend transversely to the stacking direction, for example, orthogonally to the stacking direction. The valve body can also be rotatably mounted about an axis of rotation that extends along the stacking direction or parallel to the stacking direction. In this case, the valve body can be considered a type of ball valve body and / or roller valve body.In this case, the control unit may have at least one valve body, two valve bodies, four valve bodies, six valve bodies or more valve bodies.

[0023] According to a further embodiment of the described technology, it is possible for the valve body to be cylindrical and have at least one through-opening. Thus, a rotational movement of the valve body allows for particularly quick and easy switching between the release state and the blocking state. In this case, the valve body can have two through-openings in order to establish or break a process fluid connection simultaneously on a process fluid supply side and on a process fluid outlet side. In this case, the valve body can be rotated, in particular, about an axis that extends transversely and, in particular, orthogonally to the stacking direction.Nevertheless, it is possible for a roller-shaped valve body to be positioned in the at least one main process fluid channel, in the at least one additional process fluid channel, and / or in at least one connecting channel. The valve body is mounted for rotation about an axis extending along the stacking direction. Such a valve body can also be configured such that rotation of the valve body allows switching between the release state and the blocking state.

[0024] In a further embodiment of the present invention, it is possible for the at least one main process fluid channel and the at least one additional process fluid channel to each be configured to conduct an oxidizing gas. In this case, the at least one main process fluid channel and the at least one additional process fluid channel can be understood as oxidizing gas channels for supplying oxidizing gas to the fuel cell stacks and oxidizing gas channels for discharging oxidizing gas from the fuel cell stacks. With the proposed embodiment, the desired switching on and off of the at least one additional fuel cell stack via the oxidizing gas channels can be implemented particularly efficiently. In this case, the oxidizing gas can be understood as cathode gas and / or cathode exhaust gas, for example, air and another oxygen-containing gas.The oxidation gas channel can be understood as a cathode gas channel and / or a cathode exhaust gas channel.

[0025] Furthermore, in a fuel cell system of the technology described here, it is possible for the main fuel cell stack to have more fuel cells than the at least one additional fuel cell stack. As already described above, in this case, the main fuel cell stack can be configured, in particular, to cover a base load in the vehicle, while the at least one additional fuel cell stack can be configured to cover a peak load requirement that is higher than the base load.

[0026] The described fuel cell system can comprise a first main current collector and a second main current collector on the main fuel cell stack, and an additional current collector on each additional fuel cell stack. In this way, the current generated can be particularly easily tapped from the active fuel cell stacks. The current collectors can each be integrated into the stack housing. For this purpose, the fuel cell system can, for example, have a DC / DC converter with a suitable number of switching inputs.

[0027] A further aspect of the proposed technology relates to a vehicle having a fuel cell system as described above and at least one electric motor for driving the vehicle, wherein the fuel cell system is configured to supply power to the at least one electric motor. The vehicle thus offers the same advantages as have been described in detail with reference to the fuel cell system. The vehicle can be understood to mean a motor vehicle such as a motor-driven two-wheeler, a passenger car, and a truck. The vehicle can also be understood to mean a road vehicle, an aircraft, a watercraft, a rail vehicle, a spacecraft, and a robot. The vehicle can also be understood to mean a purely electric vehicle and a hybrid electric vehicle, which, in addition to the at least one electric motor, has an internal combustion engine for driving the vehicle.The vehicle can be understood as a so-called FCEV (Fuel Cell Electric Vehicle).

[0028] Further measures will become apparent from the following description of various exemplary embodiments, which are schematically illustrated in the figures. All features and / or advantages arising from the claims, the description, or the figures, including structural details and spatial arrangements, may be significant both individually and in various combinations.

[0029] They show schematically: Fig. 1 a fuel cell system according to a first embodiment of the present technology in a first operating state, Fig. 2 the fuel cell system according to the first embodiment of the present technology in a second operating state, Fig. 3 shows a fuel cell system according to a second embodiment of the present technology in a first operating state, Fig. 4 shows the fuel cell system according to the second embodiment of the present technology in a second operating state, Fig. 5 shows a fuel cell system according to a third embodiment of the present technology in a first operating state, Fig. 6 the fuel cell system according to the third embodiment of the present technology in a second operating state, Fig. 7 shows a fuel cell system according to a fourth embodiment of the present technology in a first operating state, Fig. 8 shows the fuel cell system according to the fourth embodiment of the present technology in a second operating state, Fig. 9 shows a fuel cell system according to a fifth embodiment of the present technology in a first operating state, Fig. 10 the fuel cell system according to the fifth embodiment of the present technology in a second operating state, Fig. 11 shows a fuel cell system according to a sixth embodiment of the present technology in a first operating state, Fig. 12 the fuel cell system according to the sixth embodiment of the present technology in a second operating state, Fig. 13 a plan view of a stacking arrangement, Fig. 14 a vehicle with a fuel cell system according to an embodiment of the present technology.

[0030] Elements with the same function and mode of operation are provided with the same reference symbols in the figures.

[0031] Fig. Figure 1 shows a fuel cell system 10 according to a possible embodiment. The illustrated fuel cell system 10 has a main fuel cell stack 12 comprising a plurality of fuel cells and six main process fluid channels 17. The main process fluid channels 17 are Fig. 13 and comprise an anode gas channel 31, an anode exhaust gas channel 32, a coolant supply channel 33, a coolant outlet channel 34, a cathode gas channel 35 and a cathode exhaust gas channel 36. The main process fluid channels 17 each extend in a stacking direction 18 through the main fuel cell stack 12. The fuel cell system 10 shown also has an additional fuel cell stack 13, which also comprises several fuel cells and six additional process fluid channels 19. The six additional process fluid channels 19 correspond to the Fig. 13 and extend in the stacking direction 18 through the additional fuel cell stack 13.

[0032] The Fig. The fuel cell system 10 shown in Figure 1 further comprises a control unit 14 for controlling a process fluid mass flow through the main process fluid channels 17 and the additional process fluid channels 19. More specifically, the Fig. 1, the control unit 14 illustrated by way of example is configured to control the cathode gas flow through the cathode gas channel 35 and the cathode exhaust gas flow through the cathode exhaust gas channel 36. In alternative embodiments, the control unit 14 could alternatively or additionally be positioned in additional or fewer process fluid channels 17, 19 and / or be configured to alternatively or additionally control the process fluid mass flow in additional or fewer process fluid channels 17, 19. The main fuel cell stack 12 and the auxiliary fuel cell stack 13 are installed in the same stack housing 16 of the fuel cell system 10.

[0033] The control unit 14 can be set to a locking state S2 and an enabling state S1. The locking state S2 is in Fig. 1 and the release state S1 is in Fig. 2. In the illustrated blocking state S1, a process fluid connection between the cathode gas channel 35 of the main fuel cell stack 12 and the cathode gas channel 35 of the auxiliary fuel cell stack 13, as well as a process fluid connection between the cathode exhaust gas channel 36 of the main fuel cell stack 12 and the cathode exhaust gas channel 36 of the auxiliary fuel cell stack 13, are blocked. This means that in the embodiment shown, the control unit 14 is set such that no cathode gas can flow from the main fuel cell stack 12 to the auxiliary fuel cell stack 13, and no cathode exhaust gas can flow from the auxiliary fuel cell stack 13 to the main fuel cell stack 12.

[0034] In the release state S1, which is Fig. 2, a process fluid connection is established between the cathode gas channel 35 of the main fuel cell stack 12 and the cathode gas channel 35 of the auxiliary fuel cell stack 13, and a process fluid connection is established between the cathode exhaust gas channel 36 of the main fuel cell stack 12 and the cathode exhaust gas channel 36 of the auxiliary fuel cell stack 13. In this case, the control unit 14 is set such that cathode gas can flow from the main fuel cell stack 12 to the auxiliary fuel cell stack 13, and cathode exhaust gas can flow from the auxiliary fuel cell stack 13 to the main fuel cell stack 12. This means that the main fuel cell stack 12 and the one auxiliary fuel cell stack 13 are in process fluid communication with each other.

[0035] As in Fig. 1 and Fig. As shown in Figure 2, the control unit 14 is installed within the stack housing 16. A connecting channel 21 is formed between the cathode gas channel 35 of the main fuel cell stack 12 and the cathode gas channel 35 of the auxiliary fuel cell stack 13, as well as between the cathode exhaust gas channel 36 of the main fuel cell stack 12 and the cathode exhaust gas channel 36 of the auxiliary fuel cell stack 13. The control unit 14 is formed in the connecting channels 21. In the embodiment shown, the control unit 14 is therefore installed in the stacking direction 18 between the main fuel cell stack 12 and the one auxiliary fuel cell stack 13. The illustrated control unit 14 can be understood as a cylindrical valve body 23 with two through openings 24, wherein the valve body 23 is rotatably positioned for setting the release state S1 and for setting the blocking state S2. To adjust the control unit 14 orof the valve body 23 from that shown in . Fig. 1 shown blocking state S2 in the Fig. In the release state S1 shown in Figure 2, the valve body 23 can be rotated by 90°. If the valve body 23 is rotated in a range between 0° and 90° about the rotation axis 29, which extends orthogonally to the stacking direction 18, the maximum flow cross-sectional area between the cathode gas channels 35 and the cathode exhaust gas channels 36 of the two fuel cell stacks 12, 13 can be changed. By changing the flow cross-sectional area, the mass flow of the cathode gas from the main fuel cell stack 12 to the additional fuel cell stack 13 and the mass flow of the cathode exhaust gas from the additional fuel cell stack 13 to the main fuel cell stack 12 can be controlled or controlled and / or regulated.

[0036] The Fig. 1 and Fig. The fuel cell system 10 shown in Figure 2 has a first main current collector 25 and a second main current collector 26 on the main fuel cell stack 12, as well as an additional current collector 27 on the additional fuel cell stack 13. Depending on the switching state of the control unit 14, the current generated by the fuel cell stacks 12, 13 can be tapped by means of the current collectors 25, 26, 27, either from the main fuel cell stack 12 alone or in combination from the main fuel cell stack 12 and the additional fuel cell stack 13. For this purpose, the fuel cell system can have a DC / DC converter (not shown). In an alternative embodiment with several additional fuel cell stacks, it is possible to configure the current collectors and, if applicable, the DC / DC converter such that, at least in a certain operating state of the fuel cell system 10, only current is drawn from one or more additional fuel cell stacks 13.

[0037] The Fig. 1 and Fig. The fuel cell system 10 shown in Figure 2 further comprises an actuator 15, by means of which the control unit 14 can be set and / or adjusted to the desired state. The actuator 15 is controlled by a control unit 28, which can be considered part of the fuel cell system 10. The control unit 28 can be configured such that the actuator 15 is controlled depending on a predefined and / or depending on a predefinable operating state of the fuel cell system 10. Accordingly, the fuel cell system 10 can be configured such that the control unit 14 is set to the enable state S1 or the disable state S2 depending on the predefined and / or depending on the predefinable operating state of the fuel cell system 10.The actuator 15 can be understood as an adjustment mechanism that is configured to adjust the control unit 14 into the release state S1, the lock state S2, and a state between the release state S1 and the lock state S2. In . Fig. 1 and Fig. 2, the illustrated main fuel cell stack 12 has more fuel cells than the additional fuel cell stack 13.

[0038] In Fig. 3 and Fig. 4 shows a fuel cell system 10 according to a second embodiment. The fuel cell system 10 shown there is characterized in particular by the fact that the control unit 14 or at least a part of the control unit 14 is positioned rotatably about a rotation axis 30 that extends along the stacking direction 18. The adjustment of the control unit 14 between the release state S1 and the blocking state S2 is shown in Fig. 3 and Fig. 4 is shown purely symbolically. The control unit 14 shown can, for example, comprise a vertical roller and / or a hollow cylinder, which, depending on the rotational state, opens or closes the connecting channel 21, the cathode gas channel 35, and / or the cathode exhaust gas channel 36 for a process fluid connection.

[0039] In Fig. 5 and Fig. Figure 6 shows a fuel cell system 10 according to a third embodiment. The fuel cell system 10 shown therein is characterized in particular by the fact that the control unit 14 has two tubular membranes 22, which are elastically deformable for setting the release state S1 and for setting the blocking state S2. The fuel cell system 10 further comprises a lever mechanism 20 (not shown in detail), by which the release state S1 and the blocking state S2 can be set using leverage. The lever mechanism 20 can be understood as part of the actuator system 15.

[0040] In Fig. 7 and Fig. Figure 8 shows a fuel cell system 10 according to a fourth embodiment. The fuel cell system 10 shown there is characterized in particular by the fact that the control unit 14 has membranes 22 that are expandable, for example, inflatable, to set the blocking state S2. To set the release state S1, the membranes 22 are compressible. In the example shown, the actuator system 15 can be used to set a negative pressure within the membranes 22 and / or a lower pressure than in the blocking state S2.

[0041] In Fig. 9 and Fig. 10 shows a fuel cell system 10 according to a fifth embodiment. The fuel cell system 10 shown there is characterized in particular by the fact that the control unit 14 is displaceably positioned for setting the release state S1 and for setting the blocking state S2. In this case, the control unit 14 is plate-shaped and has two through-openings through which, in the release state S1, cathode exhaust gas can flow from the cathode gas channel 35 of the main fuel cell stack 12 into the additional fuel cell stack 13, and cathode exhaust gas can flow from the cathode exhaust gas channel 36 of the additional fuel cell stack 13 into the main fuel cell stack 12. The actuator system 15 can have the lever mechanism described above for displacing the control unit 14 or can be configured as such.

[0042] In Fig. 11 and Fig. Figure 12 shows a fuel cell system 10 according to a sixth embodiment. The fuel cell system 10 shown therein is characterized in particular by the fact that the control unit 14 is not positioned in a connecting area between the main fuel cell stack 12 and the auxiliary fuel cell stack 13, but rather directly within the main fuel cell stack 12. More specifically, the control means 14 is installed in the cathode gas channel 35 and the cathode exhaust gas channel 36 of the main fuel cell stack 12.

[0043] Fig. 13 shows a plan view of a fuel cell system 10. In Fig. 13 shows in particular a bipolar plate with the through-openings usually designed there for forming the main process fluid channels 17 and the additional process fluid channels 19. In Fig. 13 accordingly shows in particular through-openings of the bipolar plate, which in the final stack structure of the fuel cell system form the anode gas channel 31, the anode exhaust gas channel 32, the coolant supply channel 33, the coolant outlet channel 34, the cathode gas channel 35 and the cathode exhaust gas channel 36.

[0044] In Fig. 14 shows a vehicle 100 in the form of a passenger car. The vehicle 100 has a fuel cell system 10 as described above and two electric motors 40 for driving the vehicle 100, wherein the fuel cell system 10 is configured to supply power to the electric motors 40. The vehicle 100 further has a high-pressure tank 50 filled with fuel for supplying fuel to the fuel cell system 10.

[0045] The technology disclosed here allows for further design principles in addition to the embodiments shown. This means that the technology should not be considered limited to the embodiments explained with reference to the figures. List of reference symbols 10 Fuel cell system 12 main fuel cell stacks 13 additional fuel cell stacks 14 Control unit 15 Actuators 16 stackable enclosures 17 Main process fluid channel 18 Stacking direction 19 Additional process fluid channel 20 lever mechanism 21 connecting channel 22 Membran 23 Valve body 24 passage opening 25 first main pantograph 26 second main pantograph 27 first additional pantograph 28 Control unit 29 axis of rotation 30 axis of rotation 31 Anode gas channel 32 Anode exhaust duct 33 Coolant supply channel 34 Coolant outlet channel 35 Cathode gas channel 36 Cathode exhaust channel 40 electric motor 50 high-pressure vessels 100 vehicles S1 release state S2 Locked state

Claims

[1] Fuel cell system (10) for a vehicle (100), comprising: - a main fuel cell stack (12) comprising a plurality of fuel cells and at least one main process fluid channel (17), wherein the main process fluid channel (17) extends through the main fuel cell stack (12) in a stacking direction (18), - at least one additional fuel cell stack (13) comprising a plurality of fuel cells and at least one additional process fluid channel (19), wherein the additional process fluid channel (19) extends through the additional fuel cell stack (13) in the stacking direction (18), - a control unit (14) for controlling a process fluid mass flow through the at least one main process fluid channel (17) and the at least one additional process fluid channel (19), - wherein the control unit (14) is adjustable into a release state (S1), in which a process fluid connection between the at least one main process fluid channel (17) and the at least one additional process fluid channel (19) is established, and into a blocking state (S2), in which a process fluid connection between the at least one main process fluid channel (17) and the at least one additional process fluid channel (19) is disconnected, and - a stacking housing (16), wherein - the main fuel cell stack (12), the at least one additional fuel cell stack (13) and the control unit (14) are at least partially positioned in the stack housing (16). [2] Fuel cell system (10) according to claim 1, wherein the control unit (14) is positioned in the stacking direction (18) between the main fuel cell stack (12) and the at least one additional fuel cell stack (13). [3] Fuel cell system (10) according to one of the preceding claims, wherein the control unit (14) is displaceably positioned for setting the release state (S1) and for setting the lock state (S2). [4] Fuel cell system (10) according to one of the preceding claims, comprising a lever mechanism (20) for setting the release state (S1) and for setting the lock state (S2) by means of leverage. [5] Fuel cell system (10) according to one of the preceding claims, comprising at least one connecting channel (21) between the at least one main process fluid channel (17) and the at least one additional process fluid channel (19), wherein at least a part of the control unit (14) is positioned in the connecting channel (21). [6] Fuel cell system (10) according to one of the preceding claims, wherein the control unit (14) has at least one membrane (22) which is elastically deformable for setting the release state (S1) and for setting the blocking state (S2). [7] Fuel cell system (10) according to claim 6, wherein the at least one membrane (22) is tubular. [8] Fuel cell system (10) according to one of the preceding claims, wherein the control unit (14) comprises a valve body (23) with at least one through-opening (24), wherein the valve body (23) is rotatably positioned for setting the release state (S1) and for setting the blocking state (S2). [9] Fuel cell system (10) according to claim 8, wherein the valve body (23) is cylindrical and has at least one through-opening (24). [10] Fuel cell system (10) according to one of the preceding claims, wherein the at least one main process fluid channel (17) and the at least one additional process fluid channel (19) are each configured to conduct an oxidizing gas. [11] Fuel cell system (10) according to one of the preceding claims, wherein the main fuel cell stack (12) has more fuel cells than the at least one additional fuel cell stack (13). [12] Fuel cell system (10) according to one of the preceding claims, comprising a first main current collector (25) and a second main current collector (26) on the main fuel cell stack (12) and an additional current collector (27) on each further additional fuel cell stack (13). [13] Vehicle (100) comprising a fuel cell system (10) according to one of the preceding claims and at least one electric motor (40) for driving the vehicle (100), wherein the fuel cell system (10) is configured to supply power to the at least one electric motor (40).

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