A compressor arrangement for a vehicle fuel cell system

Abstract

The invention relates to a compressor arrangement (1) for a vehicle fuel cell system (100), in particular of a commercial vehicle (200), the compressor arrangement (1) comprising a first compressor stage (3) configured to draw air (A) from a first-stage inlet interface (9), pressurize the air (A) and supply it as pressurized air (Ap) to a first-stage outlet interface (11), a second compressor stage (5), comprising a second-stage inlet interface (13) downstream of and in fluid communication with the first-stage outlet interface (11) and configured to further pressurize the compressed air (Ap), and supply the further compressed air (Ap) to a fuel cell stack arrangement (7), and an expander stage (8) comprising a turbine inlet (21) configured to receive exhaust air (AE) from the fuel cell stack arrangement(7) to relax the exhaust air (AE) and to release it as relaxed exhaust air (AR). It is suggested that the second compressor stage (5) comprises a dual-flow compressor device (14), said compressor device (14) having two compressor wheels (14a, 14b) operatively coupled to a common second-stage drive shaft (14c).

Description

[0001] A compressor arrangement for a vehicle fuel cell system

[0002] The present invention relates to a compressor arrangement for a vehicle fuel cell system, in particular of a commercial vehicle, the compressor arrangement comprising a first compressor stage configured to draw air from a first-stage inlet interface, pressurize the air and supply it as pressurized air to a first-stage outlet interface, a second compressor stage, comprising a second-stage inlet interface downstream of and in fluid communication with the first-stage outlet interface and configured to further pressurize the compressed air, and supply the further compressed air to a fuel cell stack arrangement fuel cell stack arrangement as cathode-side air supply, and an expander stage comprising a turbine inlet configured to receive exhaust air from the fuel cell stack arrangement to relax the exhaust air and to release it as relaxed exhaust air to an exhausted outlet interface.

[0003] Compressor arrangements of the aforementioned type art known from the art. Two- stage compressor architectures have been used in the past to achieve improvements in compressor efficiency which is particularly important when supplying pressurized air to fuel cell systems in vehicular systems.

[0004] To mitigate challenges related to the high mechanical mass and size envelopes of compressors, in particular in view of system integration requirements, there are limitations as to the maximum size of each compressor stage and also to the integration of expander systems and compressor stages in limited spaces.

[0005] EP 3483450 A1 suggests to integrate an expander to a double stage compressor by integrating three wheels of one common shaft. This design has been found to be problematic due to the high rotation speeds necessary for the compression, leading to issues with eigenmode excitation. The increased inertia acting on the drive shaft is an additional problem.

[0006] DE 102017220855 discusses different variants of compressor / expander arrangements. The expander turbine is principally coupled mechanically to a single stage compressor, and a second compressor is connected thereto in series. It has been found out that with designs as suggested in DE 102017220855 the compressor / expander arrangement is located too close to the fuel cell, meaning that only one singular fuel cell can be sourced reliably for exhaust air, making the system difficult to scale.

[0007] Also, the expander stage is principally coupled to a second or third stage of compression with no electric motor. It has been found out that with a design such as suggested in DE 102017220855, the motorized compressor accomplishing the first compression work would have to provide about 2 / 3 of the total compression effort with no help of any expander. This would result in an electric motor with a high weight and size not compatible with mass and size envelopes limitations. Furthermore, in a design such as suggested in DE 102017220855, the compressor / expander sub-assembly accomplishes the second phase of compression and would provide about only 1 / 3 of the total compression work with an intermediate phase of compression and would provide about only 1 / 3 of the total compression work with an intermediate pressure. This in turn would result in a low rotation speed of the compressor / expander assembly and high compressor impeller and expander wheel diameters which again is detrimental to the mass and size envelope of the system.

[0008] Accordingly, it was an object of the invention, to provide a compressor arrangement which overcomes the disadvantages of the prior art as much as possible. In particular, it was an object of the invention to provide a compressor arrangement of the initially mentioned type which can be operated with improved efficiency and improved scalability to higher numbers of fuel cell stacks.

[0009] The invention achieves the object by suggesting a compressor arrangement for a vehicle fuel cell system according to claim 1 . In particular, it is suggested that the second compressor stage comprises a dual-flow compressor device, said compressor device having two compressor wheels operatively coupled to a common second-stage drive shaft. In other words, the invention allows to use a combined compressor / expander / electric motor assembly to perform the first phase of the Compression and a dual-flow compressor / motor assembly to perform the second compression phase. It has been found that this special arrangement induces an electric motor torque and speed requirement for the first stage of compression similar to the one of the second stage of compression, helping to minimize the mass and space envelope of the system. Using a dual-flow compressor device for the second compressor stage allows each of the compressor wheels in the second stage to be small relative to the compressor wheel of the first compressor stage, significantly improving the flexibility of spatially locating and orienting the second compressor stage relative to the further components of the compressor arrangement on the one hand side and the fuel cell system on the other hand side. Fluid communication between the compressor stages can be done in a flexible manner, and air supply for the number of fuel stacks can be improved accordingly.

[0010] The term “dual-flow” is meant to encompass compressor devices having to separate inlets, as well as devices having one singular inlet and an internal manifold system that distributes the inlet air to the compressor wheels.

[0011] In a preferred embodiment, the two compressor wheels of the dual-flow compressor device are oppositely pitched with respect to a sense of rotation of the second stage drive shaft. Accordingly, the second-stage drive shaft is essentially free of axial loads, since the axial forces imparted by the respective compressor wheels auto-com pensate. This improves the longevity and reduces the vibration level at higher rotation speeds of the compressor arrangement. By allowing the compressor wheels of the dual-flow compressor device to mutually compensate the axial forces, it becomes easier to increase the compression ratio of the second stage relative to the mass and size envelope of the system.

[0012] In a further preferred embodiment, the first compressor stage and the expander stage are operatively coupled to a common first-stage drive shaft. By coupling the first compressor stage to the expander stage, the energy still residing in the exhaust air can be harvested to provide additional drive power to the first-stage drive shaft further improving the efficiency of the compressor arrangement.

[0013] In a further preferred embodiment, the first compressor stage comprises a compressor wheel, and the expander stage comprises a turbine wheel, wherein the compressor wheel and the turbine wheel are oppositely pitched with respect a sense of rotation of the first-stage drive shaft. Also the compressor / expander stage can be significantly improved in terms of lower vibration level and higher longevity by auto compensating the axial loads imparted by the compressor wheel on one hand side and the turbine wheel on the other hand side. Again, the axial force compensation between the turbine wheel of the expander stage and the compressor wheel of the first compressor stage allows for a higher compression ratio of the first stage relative to the mass and size envelope of the system.

[0014] In a further preferred embodiment, the first drive shaft is coupled to a first drive motor, and the second drive shaft is coupled to a second drive motor. By providing a dedicated drive motor for each drive shaft, smaller electrical machines can be used as drive motors for each stage, wherein “small” refers to the nominal power rating provided by the electrical machines when used as a motor. Smaller drive motors tend to require less space inside the compressor arrangement, thus improving further the flexibility of layout for the compressor arrangement and fuel cell system. Inertia is further reduced, leading to improved vibration behavior, and also leading to significant improvements in the startstop behavior of the system. The air and exhaust air flow can remain simple when using dedicated drive motors because the first stage and the second stage can be directly controlled to the necessary rotational speeds. If one of the stages were to remain passive, for example, the respective other stage would require a much larger electrical motor to supply enough mass flow. A system using a plurality of dedicated drive motors can provide the needed air mass flow with more immediacy, i. e. with less of a delay. Changes in mass flow, which result from changes in air requirements on the fuel-cell side can be better met when using dedicated drive motors for each compressor stage, such that the compressor arrangement using first drive motor and second drive motor can be driven more dynamically as compare to systems using only on singular drive motor.

[0015] In a further preferred embodiment, the first and second drive motors are dimensioned identically. The dimensioning again refers to the nominal power provided by the respective drive motors. Since the first stage drive motor is additionally applied with torque by the turbine wheel of the expander stage, it would also be feasible to dimension the first drive motor smaller, i.e. with a lower nominal power rating then the second drive motor.

[0016] In a further preferred embodiment, the second compressor stage comprises a second- stage outlet interface that is configured to combine the pressurized air supply from the compressor wheels to a common supply air flow path. Alternatively, the second-stage outlet interface may be configured to separately supply the pressurized air supply from the compressor wheels to a first supply air flow path and a second supply air flow path. Dividing up the supply air into different flow paths increases the flexibility of arrangement of a higher fuel cell stack arrangement in the vehicle system.

[0017] The invention has herein above been described in a first aspect relating to the compressor arrangement itself. In a second aspect, the invention further relates to a fuel cell system of a vehicle, in particular a commercial vehicle, said system being configured to provide electrical energy to an electrical system of the vehicle and comprising a compressor arrangement, a fuel cell stack arrangement and an expander stage, wherein the compressor arrangement is in fluid communication with an configured to supply cathode-side pressurized air to the fuel cell stack arrangement, and the expander stage is in fluid communication with and configured to receive pressurized exhaust air from the fuel cell stack arrangement.

[0018] The invention achieves the object mentioned initially by suggesting that the fuel cell system comprises a compressor arrangement that is formed according to anyone of the preferred embodiment described herein-above for the first aspect.

[0019] The invention is based upon the same findings and benefits described herein-above for the first aspect. Preferred embodiments of the compressor arrangement of the first aspect are at the same time also preferred embodiments of the fuel cell system of this aspect and vice versa, such that references made to the description herein-above to avoid unnecessary repetition. Relating to both the first and second aspect, the number of fuel cell stacks is understood to be refrain to one or more fuel cell stacks in general.

[0020] In a preferred embodiment, the compressor arrangement is formed such that the second-stage outlet interface is configured to combine the pressurized air supplied from the compressor wheels to a common supply air flow path, and the fuel cell stack arrangement comprises one or more fuel cell stacks, preferably a plurality of parallel fuel cell stacks, in fluid communication with the supply air flow path. ln an alternatively preferred embodiment, the compressor arrangement is formed such that the second-stage outlet interface is configured to separately supply the pressurized air supplied from the compressor wheels to a first supply air flow path and a second supply air flow path, and the fuel cell stack arrangement comprises a first subset of at least one stack in fluid communication with the first supply air flow path and a second subset of at least one stack in fluid communication with the second supply air flow path.

[0021] As can be seen here, the use of a multi-stage compressor arrangement having a dualflow second stage compressor rarely improves the flexibility of arranging and scaling the fuel cell system with a plurality of fuel cell stacks.

[0022] In a further preferred embodiment, the first subset and / or the second subset comprises a plurality of fuel cell stacks connected in parallel to the respective supply air flow path.

[0023] In a further preferred embodiment, the number of fuel cell stacks within each subset is identical.

[0024] In a further aspect, the invention further relates to a vehicle, preferably a commercial vehicle, comprising an electrical system and a fuel cell system configured to supply electrical energy to the electrical system.

[0025] The invention achieves the object mentioned initially for such a vehicle in that the fuel cell system is configured according to anyone of the preferred embodiments describes herein above for the second aspect.

[0026] In the third aspect, the invention is based upon the same findings and benefits as the first and second aspects, and preferred embodiments of the first and second aspects are at the same time also preferred embodiments of the vehicle according to the third aspect and vice versa, such that again reference is made to the description hereinabove to avoid unnecessary repetition.

[0027] The invention is herein after described in more detail with reference to the accompanying drawings of preferred embodiments, wherein, Fig. 1 shows a schematic layout of a vehicle comprising a compressor arrangement according to the present invention in a first preferred embodiment,

[0028] Fig. 2 shows an amended layout of the vehicle of Fig. 1 , and

[0029] Fig. 3 shows a further amended layout of the vehicle according to figures 1 and 2.

[0030] The first embodiment shown in Fig. 1 comprises a compressor arrangement 1 which is provided to a vehicle 200, which may for example be a commercial vehicle. The compressor arrangement 1 is configured to provide cathode-side pressurized air Ap to a fuel cell system 100. It shall be understood that the fuel cell system 100 may necessitate or at least benefit from further components for the production of electrical energy PE, such as a hydrogen supply and electronic control units. Those elements are not shown in the Figures as they are not pertaining to the invention said forth herein below and herein above.

[0031] The compressor arrangement 1 comprises a first compressor stage 3 that is configured to draw an air A, pressurize the air A and output pressurized air Ap at a first pressure pi .

[0032] The compressed arrangement 1 further comprises a second compressor stage 5 arranged downstream off and in fluid communication with the first compressor stage 3. The second compressor stage 5 is configured to receive the pressurized air Ap further pressurized the pressurized air Ap to a second pressure p2 which is higher than the first pressure pi and output the further pressurized air Ap.

[0033] In particular, the first compressor stage 3 comprises a first-stage inlet interface 9 configured to receive air, for example from the environment. The first compressor stage 3 further comprises a compressor wheel 10 and a first-stage outlet interface 11 configured to expel the pressurized air as function of operating the compressor wheel 10.

[0034] The first compressor stage 3 comprises a first drive shaft 12 which the compressor wheel 10 is operatively coupled to. The first compressor stage 3 comprises a first electrical machine which is configured to operate as a first electric motor 16 to rotate the compressor wheel 10 in a sense of rotation Ri. The second compressor stage 5 comprises a second-stage inlet interface 13 and a second-stage outlet interface 15. The second compressor stage 5 comprises a compressor device 14 having a first compressor wheel 14a and a second compressor wheel 14b which are operatively coupled to a common second drive shaft 14c. The second compressor stage 5 comprises a second electrical machine 18 which is configured to operate as an electric motor to drive the compressor wheels 14a, 14b. To supply the pressurized air Ap to the compressor wheels 14a, 14b, the second-stage inlet interface 13 is configured as a dual inlet interface having a first air inlet 13a and a second air inlet 13b, wherein each of the dedicated inlets 13a, 13b is directly coupled to one of the compressor wheels 14a, 14b of the compressor device 14. The compressor device 14 of the second compressor stage 5 thus is a dual-flow compressor device.

[0035] Drive shaft 14c and drive shaft 22 will be put into rotation by the respective dedicated electrical motors 16, 18. The sense of rotation R1 , R2 may be chosen as required for the particular design and may be identical or opposite to one another. The rotational speeds of the drive shafts will be chosen according to the layout of the respective compressor wheels and the required flow rates of air.

[0036] The compressor wheels 14a, 14b of the second compressor stage 5 may be dimensioned smaller than the compressor wheel 10 of the first compressor stage 3, since each of the compressor wheels 14a, 14b only has to operate with a portion, namely half of the pressurized air Ap conveyed through the first compressor stage 3. If, for example, the first compressor stage 3 would operate to transport a flow rate of 300g / s, each of the compressor wheels 14a, 14b of the second compressor stage 5 would need to transport a flow rate of 150g / s of the pressurized air Ap.

[0037] A fuel cell stack arrangement 7 is arranged downstream of the compressor arrangement 1 , in particular downstream of the second compressor stage 5, and is connected in fluid communication to the second-stage outlet interface 15. The fuel cell stack arrangement 7 is configured to receive the further pressurized air Ap at pressure P2 as cathode-side air supply and use the supplied air to generate electrical energy PE. The fuel cell stack arrangement 7 is configured to provide the generated electrical energy PE to an electrical system 300 of the vehicle 200. The fuel cell stack arrangement 7 is further designed to discharge exhaust air AE at a third pressure ps which typically would be lower than the first pressure pi and / or the second pressure p2.

[0038] An expander stage 8 is arranged downstream of the fuel cell stack arrangement 7 and connected to the fuel cell stack arrangement 7 in fluid communication through an exhaust line 19 which connects to a turbine inlet 21 of the expander stage 8. The expander stage 8 comprises a turbine wheel 22 which is configured to expand the exhaust air Aeprovided through the turbine inlet and discharge relaxed exhaust air AR through a turbine outlet 23. In the embodiment shown, the expander stage 8 and the first compressor stage 3 have a common drive shaft, namely the drive shaft 12 that is used to drive the first compressor wheel 10. This way, the expander stage 8 can harvest any kinetic energy still present in the exhaust air AE and contribute to driving the drive shaft 12 of the first compressor stage 3.

[0039] Since the first compressor stage 3, however, comprises the dedicated electrical machine i.e. electric motor 16, the fuel cell system 100 does not need to rely on torque provided by the expander stage 8 to start up or drive the first compressor stage 3, leading to an improved reaction time when starting up, driving and shutting down the air flow of the compressor arrangement 1.

[0040] By virtue of configuring the second compressor stage 5 with a dual-flow compressor device 14, several benefits can be achieved which shall be explained below. A first benefit which is common to all the embodiments shown here is that the second compressor stage 5 may be designed with a relatively small space requirement, since the compressor wheels 14a, 14b may be designed comparatively small at least in comparison with the first compressor stage 3. This provides more options for placing the second compressor stage 5 inside the vehicle 200. It also provides several beneficial options for transporting the pressurized air Ap to the fuel cell stack arrangement 7, which leads to further options for scaling the fuel cell stack arrangement 7 to more than one fuel cell stack 7a as shown in Fig. 1 , or with a plurality of fuel cell stacks 7a, 7b, 7c, 7d as shown in the Figures 2 and 3. In fig. 1 , the second compressor stage 5 discharges the pressurized air Ap to a common supply air flow path 17 which can then be used to supply the fuel cell stack arrangement 7 with cathode-side air supply. As a variant of this concept, and shown in Fig. 2, the fuel cell stack arrangement 100 preferably comprises a first supply air flow path 17a and a parallel second supply air flow path 17b, wherein the first supply air flow path 17a is in fluid communication with a first outlet 15a of the second-stage outlet interface 15 and the second supply air flow path 17b is in fluid communication with a second outlet 15b of the second stage outlet interface 15. This increases the options of orienting and spacing the second compressor stage 5 and the fuel cell stacks of the fuel cell stack arrangement 7 from one another.

[0041] In the embodiment shown in Fig. 2, the fuel cell stack arrangement 7 comprises a first fuel cell stack 7a and a parallel second fuel cell stack 7b. The first fuel cell stack 7a is part of a first subset 24a, where in the second fuel cell 7b is part of a second subset 24b. The first supply air flow path 17 a connects the second compressor stage 5 to the first subset 24a, wherein the second supply air flow path 17b connects the second compressor stage 5 to the second subset 24b.

[0042] As can be seen in particular in Fig. 3, which is a further variation of the layout shown in fig. 2, this allows for improved scaling of the fuel cell stack arrangement 7. The layout shown in fig. 3 is largely identical of the layout of Fig. 2 except that each subset 24a, 24b comprises a plurality of fuel cell stacks. Namely, the first subset 24a comprises at least a first fuel cell stack 7a and a second fuel cell stack 7b, wherein the second subset 24b comprises at least a third fuel cell stack 7c and a fourth fuel cell stack 7d. Depending on the configuration of the parallel compressor wheels 14a, 14b of the second compressor stage 5, the number of fuel cell stacks in each subset 24a, 24b may be identical, as shown in Fig. 3, or may be distinct from one another.

[0043] It shall be understood that the preferred embodiments shown in Figs. 1 to 3 will in practice encompass further functional and / or structural parts as may be required or desired for operating the fuel cell system, some of which shall be briefly described hereinbelow.

[0044] The flow path of the cathode-side air supply may comprise an intercooler 25, wherein the intercooler 25 is preferably interposed between the first stage outlet interface 11 and the second stage inlet interface 13. Alternatively, the intercooler 25, or an additional intercooler (not shown), might also be positioned along the common supply air flow path 17 downstream of the second compressor stage 5. The fuel cell system 100 may comprise a scavenger valve 27 arranged so as to bypass the fuel cell stack arrangement 7. The scavenger valve 27 preferably branches off from the common supply air flow path 17 downstream of the second compressor stage 5 and upstream of the fuel cell stack arrangement 7.

[0045] The fuel cell system 100 may further comprise one (cf. fig. 1 ) or more (figs. 2 and 3) pressure control valves 29 located downstream of the fuel cell stack arrangement 7. In the embodiments using a plurality of fuel cell stacks 7a, 7b (fig. 2); 7a, 7b, 7c, 7d (fig. 3), the fuel cell system 100 may comprise one pressure control valve 29 downstream of each fuel cell stack 7a, 7b (fig. 2); 7a, 7b, 7c, 7d (fig. 3).

[0046] The fuel cell system 100 further may comprise a bypass valve 31 that is configured to bypass the expander stage 8. Preferably, the bypass valve 31 branches off from the exhaust line 19.

[0047] List of reference signs (Part of the description) compressor arrangement first compressor stage second compressor stage fuel cell stack arrangementa, b, c, d fuel cell stack expander stage first-stage inlet interface 0 compressor wheel I first-stage outlet interface 2 first drive shaft 3 second-stage inlet interface3a first second-stage air inlet3b second second-stage air inlet4 dual-flow compressor device4a first compressor wheel 4b second compressor wheel4c common second drive shaft5 second-stage outlet interface5a first second-stage outlet 5b second second-stage outlet6 first electric motor 7 common supply air flow path7a first supply air flow path 7b second supply air flow path8 second electric motor 9 exhausted line 1 turbine inlet 2 turbine wheel 3 turbine outlet 4a first subset 4b second subset 5 intercooler 7 scavenger valve 29 pressure control valve

[0048] 31 bypass valve

[0049] 100 fuel cell system

[0050] 200 vehicle

[0051] 300 electrical system

[0052] A air

[0053] AE exhaust air

[0054] Ap pressurized air

[0055] AR relaxed exhaust air

[0056] PE electrical energy

[0057] Ri , R2 sense of rotation

Claims

1. A compressor arrangement (1 ) for a vehicle fuel cell system (100), in particular of a commercial vehicle (200), the compressor arrangement (1 ) comprising:- a first compressor stage (3) configured to draw air (A) from a first-stage inlet interface (9), pressurize the air (A) and supply it as pressurized air (AP) to a first-stage outlet interface (11 ),- a second compressor stage (5), comprising a second-stage inlet interface (13) downstream of and in fluid communication with the first-stage outlet interface (11 ) and configured to further pressurize the compressed air (AP), and supply the further compressed air (AP) to a fuel cell stack arrangement (7), and- an expander stage (8) comprising a turbine inlet (21 ) configured to receive exhaust air (AE) from the fuel cell stack arrangement(7) to relax the exhaust air (AE) and to release it as relaxed exhaust air (AR), characterized in that the second compressor stage (5) comprises a dual-flow compressor device (14), said compressor device (14) having two compressor wheels (14a, 14b) operatively coupled to a common second-stage drive shaft (14c).

2. The compressor arrangement (1 ) of claim 1 , characterized in that the two compressor wheels (14a, 14b) of the dual-flow compressor device (14) are oppositely pitched with respect to a sense of rotation (R2) of the second- stage drive shaft (18).

3. The compressor arrangement (1 ) of claim 1 or 2, characterized in that the first compressor stage (3) and the expander stage (8) are operatively coupled to a common first-stage drive shaft (12).

4. The compressor arrangement (1 ) of claim 3, wherein the first compressor stage (3) comprises a compressor wheel (10), and the expander stage (8) comprises a turbine wheel (22) wherein the compressor wheel (10) and the turbine wheel (22) are oppositely pitched with respect to a sense of rotation (R1) of the first-stage drive shaft (12).

5. The compressor arrangement (1 ) of any one of the preceding claims, characterized in that the first drive shaft (12) is coupled to a first drive motor (16), and the second drive shaft (14c) is coupled to a second drive motor (18).

6. The compressor arrangement (1 ) of claim 5, wherein the first and second drive motors (16, 18) are dimensioned identically.

7. The compressor arrangement (1 ) of any one of the preceding claims, characterized in that second compressor stage (5) comprises a second-stage outlet interface (15) that is configured to combine the pressurized air (AP) supplied from the compressor wheels (14a, 14b) to a common supply air flow path (17).

8. The compressor arrangement (1 ) of any one of claims 1 to 6, characterized in that the second-stage outlet interface (15) is configured to separately supply the pressurized air (AP) supplied from the compressor wheels (14a, 14b) to a first supply air flow path (17a) and a second supply air flow path (17b).

9. A fuel cell system (100) of a vehicle (200), in particular a commercial vehicle (200), said system being configured to provide electrical energy (PE) to an electrical system (300) of the vehicle (200) and comprising:- a compressor arrangement (1 ), a fuel cell stack arrangement (7), and an expander stage (8), wherein the compressor arrangement (1 ) is in fluid communication with and configured to supply pressurized air (AP) to the fuel cell stack arrangement (7), and the expander stage (8) is in fluid communication with and configured to receive exhaust air (AE) from the fuel cell stack arrangement (7), characterized in that the compressor arrangement (1 ) is formed according to any one of the preceding claims.

10. The fuel cell system (100) of claim 9, wherein the compressor arrangement (1 ) is formed according to claim 7, and the fuel cell stack arrangement (7) comprises one (7a) or more fuel cell stacks, preferably a plurality of fuel cell stacks, in fluid communication with the common supply air flow path (17).11 . The fuel cell system (100) of claim 9, wherein the compressor arrangement (1 ) is formed according to claim 8, and thefuel cell stack arrangement(7) comprises a first subset (24a) of at least one stack (7a; 7a, 7b) in fluid communication with the first supply air flow path (17a), and a second subset (24b) of at least one stack (7b; 7c, 7d) in fluid communication with the second supply air flow path (17b).

12. The fuel cell system (100) of claim 11 , wherein the first subset (24a) and / or the second subset (24b) comprises a plurality of fuel cell stacks (7a, 7b; 7c, 7d) connected in parallel to the respective supply air flow path (17a, 17b).

13. The fuel cell system (100) of claim 12, wherein the number of fuel cell stacks within each subset is identical.

14. A vehicle (200), preferably a commercial vehicle (200), comprising an electrical system (300) and a fuel cell system (100) configured to supply electrical energy (PE) to the electrical system (300), characterized in that the fuel cell system (100) is configured according to any one of claims 9 to 13.

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