Method for operating a vehicle having a fuel cell system and fuel cell system therefor

Abstract

The invention relates to a method for operating a vehicle (200), in particular a commercial vehicle, having a fuel cell system (100), the fuel cell system (100) having a cathode-side flow path (16) which is fluidically connected to the environment (U), the cathode-side flow path (16) serves for conveying air from the environment to the fuel cell system and for conveying cathode exhaust gas from the fuel cell system into the environment, and a fluid-conducting component (24) which is connected in a fluid-conducting manner to the cathode-side flow path (16), according to the invention, the fluid-conducting means are designed to receive an accumulation of condensate (K) from air or cathode exhaust gas (LK), and the vehicle (200) has a compressed air supply (301) which is independent of the fuel cell system (100) and is designed to provide dry compressed air (LT). It is proposed that the method comprises blowing (407, 419) dry compressed air (LT) through a compressed air supply (301) into the cathode-side flow path (16), such that the fluid-conducting component (24) is flowed through by the dry compressed air (LT), and such that air or cathode exhaust gas and / or condensate (K) present is displaced from the fluid-conducting component (24) in the direction of the environment (U).

Description

Technical Field

[0001] The invention relates to a method for operating a vehicle, in particular a commercial vehicle, having a fuel cell system, wherein the fuel cell system has a cathode-side flow path connected to the environment in a fluid-conducting manner, the cathode-side flow path being used to convey air from the environment (U) to the fuel cell system and to convey cathode exhaust gas from the fuel cell system into the environment (U), and a fluid-conducting component connected to the cathode-side flow path in a fluid-conducting manner, the fluid-conducting component being designed to receive condensate accumulations from the air or the cathode exhaust gas, and the vehicle having a compressed air supply that is independent of the fuel cell system and is designed to provide dry compressed air to the fuel cell system. Background Art

[0002] Methods of the type described above are well known. In the process of energy transition, hydrogen as a form of energy is becoming increasingly important in the automotive sector, and in particular in the commercial vehicle sector. A core challenge in the operation of a fuel cell system is the efficiency of the fuel cell system and the stability of the fuel cell system. Within the fuel cell system, in addition to providing oxygen (air) as a cathode-side reactant through a compressor assembly, the cathode exhaust gas leaving the fuel cell is discharged through an expander assembly, wherein the compressor and expander are not necessarily constructed as an integrated structural unit, but this is generally the case.

[0003] After passing through the fuel cell, the cathode exhaust gas will have a substance mixture consisting of water and air, in which water is present both in the form of droplets and in a highly saturated state bound in the air. Before passing through the fuel cell of the fuel cell system, moisture may also be present in the ambient air in the flow path on the cathode side.

[0004] When air and / or cathode exhaust gas are conveyed through the flow path, cooling of the air and / or cathode exhaust gas may occur partially during operation of the fuel cell system, but especially at the end of operation, thereby causing condensation of water. Pressure drops in the flow path also cause condensation of water from the air or cathode exhaust gas.

[0005] Although undesirable, there are always locations within the flow path at the fluid-conducting components of the fuel cell system where condensate can accumulate. In this regard, it was mentioned above that the fluid-conducting components are designed to receive condensate accumulations from the air or cathode gas, which should be understood to mean that, due to space or technical requirements, the components also undesirably have areas in which condensate can accumulate and in this sense be received by these components.

[0006] In the long term, water can lead to corrosion, but also at least to increased friction of movable fluid-carrying components and to adversely affect the efficiency and / or stability of the fluid-carrying components and thus the entire fuel cell system. If condensation freezes inside the fluid-carrying components, there is the threat of component damage and, in the worst case, of functional failure of the fuel cell system.

[0007] Several solutions are known from the prior art, in which it is proposed that the compressor assembly of the fuel cell system continue to operate at the end of the operation of the fuel cell system and dry the fuel cell itself. Such systems are described, for example, in DE 10 2020 202283 A1 or DE 10 2019 214 748 A1.

[0008] However, it turns out that using the system's own compressor for drying does not guarantee that critical locations in the flow path on the cathode side are completely free of water accumulation. Summary of the invention

[0009] The object of the present invention is therefore to overcome the above disadvantages to the greatest extent possible in a method of the type mentioned at the outset. In particular, the object of the present invention is to provide a method which allows for more reliable drying of fluid-carrying components of a fuel cell system.

[0010] The invention achieves this object by providing a method according to claim 1. In particular, it is provided that the method comprises the steps of blowing compressed air into the cathode-side flow path by means of a compressed air supply, so that the fluid-conducting component is flowed through by the compressed air and the existing air and / or existing cathode exhaust gas and / or condensate are displaced from the fluid-conducting component in the direction of the environment.

[0011] In the context of the present invention, when dry compressed air is mentioned, compressed air is to be understood as compressed air that complies with ISO 8573-1:2010, class 6 or better, in particular class 4 or better.

[0012] The invention is based on the recognition that in the prior art, the air driven through the fuel cell by means of a compressor after operation always still contains moisture, which can condense due to external influences, in particular cooling of the system and / or the environment, and can accumulate at corresponding locations in the fluid-conducting components.

[0013] The invention proceeds from this and makes full use of the fact that a compressed air supply with dry compressed air is already present in the (commercial) vehicle in which the method described at the outset is used, since this dry compressed air is required, for example, for the brake system and / or air suspension system of the (commercial) vehicle. The invention proposes to use the technically prepared dry compressed air of the compressed air supply instead of the air which may be provided by any compressor components of the fuel cell system and which always entrains some residual moisture from the environment into the system, and to blow this dry compressed air into the flow path so that moisture of the air or cathode exhaust gas still in the system is driven out and any condensate accumulations within the fuel cell system are entrained and driven out of the system.

[0014] The invention makes full use of the fact that the compressed air supply of the commercial vehicle is already designed to provide compressed air at an operating pressure that is significantly higher than that which can be provided by any compressor components of the fuel cell system, and that this compressed air can already be blown into the flow path at a sufficiently high mass flow rate without the need for additional pressure loading in order to ensure that condensate accumulations are entrained. The necessary operating parameters, such as pressure and mass flow rate, can be empirically determined by simple preliminary trials, and the amount of dry compressed air blown in can also be calibrated in a generally known manner.

[0015] The invention therefore proposes a solution which can be used for all fluid-conducting components of a fuel cell system, provided that the corresponding fluid-conducting components are structurally accessible via a compressed air line.

[0016] The invention enables and provides in a preferred embodiment that moisture can be removed from one or more fluid-conducting components simultaneously or successively by blowing in compressed air.

[0017] In a preferred development of the invention, the method comprises the step of putting the fluid-conducting component into operation, wherein the step of blowing in dry compressed air begins before or simultaneously with the start-up.

[0018] Preferably, the compressed air supply is set up to provide dry compressed air at an operating pressure of 8.0 bar or more, and the method comprises the step of reducing the blowing pressure for blowing to 6.0 bar or less, preferably in the range of 3.0 bar to 5.5 bar. It has been found that the pressure reduction leads to better results in terms of water and particle emission compared to the operating pressure usually provided by the compressed air supply and usually above 8.0 bar. In particular, the blowing is carried out at this reduced blowing pressure and at the same time providing the maximum available volume flow at the blowing pressure in order to achieve the highest possible entrainment effect.

[0019] Preferably, the step of blowing in dry compressed air begins and is completed before the fluid-conducting component is put into operation. This ensures that the operation of the fuel cell system is not arbitrarily affected by air moisture or condensation.

[0020] In another preferred embodiment, the method further comprises the step of stopping the fluid-conducting component, wherein the step of blowing in compressed air begins after or simultaneously with the stopping of the fluid-conducting component. Depending on the ambient conditions, it may be advantageous to carry out the step of blowing in dry compressed air as soon as possible after the fluid-conducting component stops operating or simultaneously with the stopping of the fluid-conducting component.

[0021] However, the invention can also be used advantageously if a certain amount of system cooling can occur before the compressed air is blown in and after the fluid-carrying components have been shut down, thereby also preventing the blowing of dry compressed air into the cathode-side flow path from having a negative impact on the operation of the fuel cell system.

[0022] Particularly preferably, in a method which also comprises the injection of dry compressed air before the fluid-conducting component is put into operation, a step of injecting dry compressed air after the fluid-conducting component has been shut down is additionally performed.

[0023] In a further preferred embodiment of the method, the step of blowing in dry compressed air is carried out for a predetermined flushing duration, which is preferably in the range of 5 seconds or more, more preferably in the range of 10 seconds or more, and particularly preferably in the range of 15 seconds or more.

[0024] In another preferred embodiment, the above preferred range is limited to a maximum flushing duration of 30 seconds or less.

[0025] More preferably, the flushing duration does not exceed 20 seconds. It has been found that after the above flushing duration, there is no residual water in the system or only a small amount of residual water, thereby reliably eliminating adverse effects on the operation of the fuel cell system.

[0026] Continuing the flushing process beyond this time will no longer achieve any measurable advantage. Therefore, limiting the maximum flushing duration can save resources without causing any adverse effects.

[0027] In another preferred embodiment, the fluid-guiding component has an expander stage of a compressor assembly of a fuel cell system, and the expander stage preferably has an expander chamber and / or an expander wheel. Alternatively or additionally, the fluid-guiding component has an air bearing assembly of a compressor assembly of a fuel cell system, and the air bearing assembly preferably has one or more air bearings, which are connected to the expander stage in a fluid-guiding manner. Alternatively or additionally, the fluid-guiding component also has a condensate separator of the fuel cell system. The condensate separator is preferably arranged in the flow path on the cathode side of the cathode exhaust gas, that is, for example, arranged downstream of the fuel cell, but upstream of the expander stage. The condensate separator is also called a droplet separator, which can remove at least droplets from the existing water content in the cathode exhaust gas. Blowing compressed air into the condensate separator can improve and accelerate the discharge of moisture from this component and the other components mentioned above. Here, the risk of damage caused by freezing in winter can also be advantageously reduced.

[0028] Alternatively or additionally, the fluid-conducting component has a compressor stage of a compressor assembly of a fuel cell system, which preferably has an expander chamber and / or an expander wheel. By blowing in dry compressed air, the risk of damage due to moisture and / or particle accumulation is also advantageously reduced in a compressor stage of the above-mentioned type. For this purpose, preferably, the compressor stage has corresponding outlet openings, which can be opened during the blowing and can be closed during the operation of the fuel cell system. In a further preferred embodiment, the compressed air supply is assigned to a pneumatic brake system of the vehicle, in particular a multi-circuit brake system. In the case of being assigned to a multi-circuit brake system, the compressed air supply is preferably connected to the auxiliary consumer circuit of the brake system.

[0029] The above has been described with reference to the first aspect of the method according to the invention. In a second aspect, the invention also relates to a fuel cell system for driving a vehicle, in particular a commercial vehicle, which has a compressed air supply that is independent of the fuel cell system and is configured to provide dry compressed air, wherein the fuel cell system has a cathode-side flow path that is connected to the environment in a fluid-conducting manner, the cathode-side flow path being used to convey air from the environment to the fuel cell system and to convey cathode exhaust gas from the fuel cell system to the environment, and a fluid-conducting component that is connected to the cathode-side flow path in a fluid-conducting manner, the fluid-conducting component being configured to receive condensate accumulations from the air or the cathode exhaust gas.

[0030] The present invention also solves the task stated at the beginning for the method in the case of a fuel cell system of the above-mentioned type in the following way, namely, the fuel cell has a valve assembly that can be switched back and forth between a blocking position and a release position, wherein the valve assembly is connected to the flow path on the cathode side in a fluid-guiding manner in the release position, and is designed to connect a compressed air supply for blowing dry compressed air into the flow path on the cathode side with the flow path in the release position, so that the fluid-guiding component is flowed through by compressed air and the existing air or existing cathode exhaust gas and / or condensate is expelled from the fluid-guiding component toward the environment.

[0031] With regard to the fuel cell system, the present invention utilizes the same advantages as the method according to the first aspect of the invention. Preferred embodiments of the method are also preferred embodiments of the fuel cell system of the second aspect, and vice versa, so that reference is also made to the above statements to avoid repetition, and with regard to preferred embodiments of the method of the present invention, reference is also made to the following statements about the fuel cell system.

[0032] In a preferred development of the fuel cell system, the valve arrangement is controllable and is designed for signal-conducting connection to a control unit, wherein the control unit is preferably designed as a brake control unit or trailer brake control unit.

[0033] The controller is preferably constructed in a generally known manner, that is, the controller has a processor device and one or more data memories and is set up to at least partially implement the method according to the invention. Preferably, the controller is set up to control the injection of compressed air into the flow path on the cathode side by actuating the valve assembly in the method of the first aspect.

[0034] The valve assembly can be actuated pneumatically, electrically, electropneumatically or hydraulically.

[0035] Depending on whether one or more fluid-carrying components in the fuel cell system should be dehydrated by blowing in compressed air, the valve assembly can include one or more controllable one-way valves or multi-way valves. In a preferred embodiment, the valve assembly is configured to control one or more of these valves synchronously or individually in order to remove moisture from the fluid-carrying components connected to the valves of the valve assembly in a fluid-carrying manner.

[0036] In a further aspect, the invention relates to a vehicle, in particular a commercial vehicle, having a fuel cell system according to one of the preferred embodiments described above, and a controller, which is connected to the valve assembly in a signal-conducting manner and is configured to control the valve assembly for blowing in compressed air in a method according to one of the preferred embodiments described above, wherein the controller is preferably configured as a controller or a trailer controller.

[0037] The vehicle utilizes the same advantages as the fuel cell system according to the second aspect of the invention and the method according to the first aspect of the invention. Therefore, preferred embodiments of the method and the fuel cell system are also preferred embodiments of the vehicle at the same time, and vice versa, so in order to avoid repetition, reference is made to the previous statements. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be described in more detail below with reference to the accompanying drawings with the aid of preferred embodiments. In the accompanying drawings:

[0039] Figure 1 A schematic diagram showing a vehicle having a fuel cell system according to a preferred embodiment, and

[0040] Figure 2 The method for operating according to the present invention is shown by way of example. Figure 1 A schematic diagram of a preferred embodiment of the method of a vehicle. DETAILED DESCRIPTION

[0041] Figure 1 A vehicle 200 , in particular a commercial vehicle, is schematically shown. The vehicle 200 has a fuel cell system 100 and a brake system 300 .

[0042] The fuel cell system 100 has a fuel cell 101, to which air L is supplied on the cathode side by a compressor assembly 1. The compressor assembly 1 has a compressor housing 3, in which a rotor shaft 5 is arranged. The rotor shaft 5 is driven by means of an electric motor 7 and is supported in a contactless manner by an air bearing assembly 9. The air bearing assembly 9 has a plurality of air bearings, of which a first radial air bearing 9a and a second radial air bearing 9b are shown here by way of example. Suitably, the air bearing assembly 9 also has one or more axial air bearings, but this is not relevant to understanding the present invention and is therefore not described for the sake of clarity. Figure 1 Hidden in the.

[0043] The compressor assembly 1 has a compressor stage 11, which has a compressor chamber 13 and a compressor wheel 15 arranged in the compressor chamber, which draws in air L from the environment U due to the rotation of the rotor shaft 5, compresses it, and transports it via a (first) flow path 14 on the cathode side for reactant delivery to the fuel cell 101.

[0044] After the conversion is completed in the fuel cell 101, the cathode exhaust gas L K The cathode exhaust gas L is conveyed via the (second) flow path 16 on the cathode side to an expander stage 17 which has an expander chamber 19 and an expander wheel 21 arranged in the expander chamber. In the expander chamber 19, the cathode exhaust gas L KThe pressure is relieved by means of the expansion wheel 21 and subsequently conveyed further into the environment U.

[0045] In the cathode-side flow path 16 , between the fuel cell 101 and the expander stage 17 , a condensate separator 23 is arranged, which is designed to collect droplet-shaped water and possibly other accumulated condensate K and remove them from the cathode exhaust gas L K It is preferably discharged in the direction of the environment U.

[0046] Condensate K may accumulate not only in the condensate separator 23 but also in other areas of the flow path 16, for example, inside the expander chamber 19 and also inside the air bearing assembly 9, which is connected to the flow path 16 in a fluid-conducting manner due to the contactless bearing arrangement due to its structure and is first connected there to the expander chamber 19. Therefore, by way of example, the potential presence of condensate K is also indicated in these areas of the fuel cell system 100.

[0047] Thus, exemplarily, the condensate separator 23 , the expander stage 17 , and the air bearing assembly 9 may be understood as a fluid-conducting component 24 .

[0048] The vehicle 200 has a valve assembly 25 which is connected in a fluid-conducting manner to the fluid-conducting component 24 via dedicated fluid lines 27 a , 27 b and 27 c .

[0049] Depending on the installation conditions and customer requirements, the valve assembly 25 can be structurally assigned to the fuel cell system 100, but it can also be structurally assigned to the brake system 300. The valve assembly 25 can also be arranged at a favorable position of the vehicle 200 as a dedicated valve assembly separately from the brake system 300 and the fuel cell system 100. The functional assignment relationship is the key. The valve assembly 25 can be selectively designed to have one or more multi-way valves, or respectively have a dedicated one-way valve.

[0050] The valve assembly 25 can be reciprocated between a release position F and a blocking position F, and is configured to establish a fluid-conducting connection between the compressed air supply portion 301 of the brake system 300 and the fluid-conducting component 24 in the cathode-side flow path 16 in the release position F, so that the dry compressed air L T Blown into the cathode-side flow path 16 and in particular into the fluid-conducting component 24. This results in dry compressed air L T The condensed exhaust gas L K Air potentially containing moisture is displaced out and any condensation K that may have accumulated is driven away from the fluid-conducting component 24 .

[0051] The brake system preferably has a particle filter 303 which is connected upstream of the valve module 25 .

[0052] The brake system 300 has a (first) control unit 305, which is preferably designed as a brake control unit or a trailer brake control unit, and is configured to switch the valve assembly 25 from the blocking position S to the release position F for a predetermined flushing duration t. S , and vice versa, in order to carry out a targeted blowing process for drying the fluid-conducting component 24. For this purpose, the controller 305 is configured to be connected to a (second) controller 307, such as a compressor control unit or a fuel cell control unit, in a signal-conducting manner and can be controlled thereby. This makes it possible in a simple manner to achieve that when one, more or all of the fluid-conducting components 24 are to be put into operation or shut down due to the start-up or shutdown of the compressor assembly 1, the valve assembly 25 can always be preferably controlled by the method according to the invention to dry the fluid-conducting component 24, which will be described below in conjunction with Figure 2 Provide explanation.

[0053] exist Figure 1 In the embodiment of the present invention, the working method is explained with reference to the fluid-conducting component 24 in the second flow path 16 on the cathode side. In a further preferred embodiment (not shown separately here for the sake of clarity), the first flow path 14 on the cathode side can alternatively or additionally have a fluid-conducting component, such as a compressor chamber 13, which is dried in the same manner and method as the fluid-conducting component 24 in the second flow path 16 on the cathode side by blowing in dry compressed air. In this regard, reference is made similarly to the above and the following statements.

[0054] Figure 2 A schematic method flow is shown, in which dry compressed air L is supplied to the compressed air supply 301. T Blown into the flow path 16 on the cathode side, so that the fluid-conducting component 24 is filled with compressed air L T flow through, and the cathode exhaust gas L K And / or condensate K is displaced out of the fluid-conducting component 24 in the direction of the environment U.

[0055] In step 401, a start intention is first initiated for the fuel cell system 101. Based on the start intention, in step 403, the control instruction B V1 The second controller 307 transmits to the first controller 305. The first controller 305 then controls the valve assembly 25 in step 405 so as to occupy the release position F.

[0056] Then, in step 407, the valve assembly 25 is in the release position for the flushing duration t S , and by passing dry compressed air L T Blowing into the flow path 16 to dry the fluid-conducting component 24 until the flushing time t S At the end, the valve assembly 25 returns to its blocking position S (step 409). This can be optionally controlled by the control instruction B of the second controller 307. V0 Triggered, or automatically controlled by the first controller 305.

[0057] In step 411, after the valve assembly 25 is successfully blocked, preferably by means of the control instruction B of the second controller 307 FC1 , putting the fuel cell system 100 into operation.

[0058] If the fuel cell system 100 is to be shut down from the ongoing operation, then in step 413, when the shutdown intention occurs, a control command B is firstly sent to the motor 7 of the compressor assembly 1, preferably again triggered by the controller 307. FC0 The control command adjusts the operation and thus stops the operation of the fluid-conducting component 24 .

[0059] At the same time or after a short delay, in step 415, the second controller 307 sends a control instruction B to the first controller 305. V1 , the valve assembly 25 then takes up its release position F in a step 417 .

[0060] In step 419, the valve assembly 25 may again be held in its release position F for the duration of the flushing process t S , in order to dry the cathode-side flow path 16 in the region of the fluid-conducting component 24 until the valve assembly 25 assumes its blocking position S again in step 421. This can be attempted as before by the control command B of the second controller 307 V0 Alternatively, the first controller 305 may be used for automatic control.

[0061] The programming effort for implementing the method is simple and efficient. The present invention thus provides a very effective and at the same time easy-to-implement system for increasing the stability and efficiency of a fuel cell system 100 of a vehicle 200 .

[0062] exist Figure 1 and Figure 2In the exemplary embodiment of FIG. 1 , a compressor assembly 1 of a fuel cell system 100 is shown, wherein the fuel cell system 100 has a plurality of fluid-conducting components 24 , each of which may (undesirably) accumulate condensate K. However, the present invention is not restricted to the configuration shown, but can essentially also be realized with a system having a smaller or larger number of fluid-conducting components 24 .

[0063] List of reference numerals (part of the description):

[0064] 1 Compressor components

[0065] 3 Compressor housing

[0066] 5 Rotor shaft

[0067] 7 Motor

[0068] 9 Air bearing assembly

[0069] 9a, 9b First and second air bearings

[0070] 11 Compressor Stage

[0071] 13. Compressor Room

[0072] 14 Flow Path

[0073] 15 Compressor wheel

[0074] 16 Flow Path

[0075] 17 Expander Stage

[0076] 19 Expander room

[0077] 21 Expander wheel

[0078] 23 Condensate separator

[0079] 24 Components for guiding fluid

[0080] 25 Valve assembly

[0081] 27a, b, c Fluid lines

[0082] 100 Fuel Cell Systems

[0083] 101 Fuel Cell

[0084] 200 vehicles

[0085] 300 Braking System

[0086] 301 Compressed air supply department

[0087] 303 Particle Filter

[0088] 305 (First) Controller, Braking System

[0089] 307 (Second) Controller, Fuel Cell System

[0090] Step 401: Start the Intention

[0091] 403 Step: Manipulation

[0092] 405 Step: Release Position

[0093] 407 Step: Blow dry compressed air into

[0094] 409 Step: Blocking Location

[0095] 411 Step: Putting fluid-carrying components into operation

[0096] 413 Step: Stop Willing, Stop Running

[0097] 415 Step: Manipulation

[0098] 417 Step: Release Position

[0099] 419 Step: Blow dry compressed air into

[0100] 421 Step: Blocking Position

[0101] F Release position

[0102] K Condensate

[0103] L Air

[0104] L K Cathode exhaust gas

[0105] L T Compressed air

[0106] S Blocking position

[0107] t S Rinse duration

[0108] U Environment

[0109] B FC0 Control instructions, compressor components

[0110] B FC1 Control instructions, compressor components

[0111] B V0 Control command, valve assembly

[0112] B V1 Control command, valve assembly

Claims

1. A method for operating a vehicle (200), in particular a commercial vehicle, having a fuel cell system (100), in, The fuel cell system (100) comprises a cathode-side flow path (16) connected to the environment (U) in a fluid-conducting manner, wherein the cathode-side flow path is used to convey air from the environment (U) to the fuel cell system (100) and to convey cathode exhaust gas (L K ) from the fuel cell system (100) to the environment (U), and having a fluid-conducting component (24) connected to the cathode-side flow path (16) in a fluid-conducting manner, the fluid-conducting component being configured to receive air (L) or cathode exhaust gas (L K ) condensate (K) accumulation, and the vehicle (200) has a fuel cell system (100) which is independent of the fuel cell system (100) and is configured to provide dry compressed air (L T ) of the compressed air supply unit (301), Characterized in that the method comprises: By means of the compressed air supply unit (301), dry compressed air (L T ) is blown (407, 419) into the flow path (16) on the cathode side so that the fluid-guiding component (24) is dried by compressed air (L T ) flows through, and the existing air (L) or the existing cathode exhaust gas (L K ) and / or condensate (K) are displaced from the fluid-conducting component (24) in the direction of the environment (U).

2. The method according to claim 1, comprising: The fluid-conducting component (24) is put into operation (411), wherein dry compressed air (L T ) The blowing step (407) is started before or simultaneously with the start-up (411).

3. The method according to claim 1 or 2, in, The dry compressed air (L T ) The blowing step (407) is started and completed before the fluid-conducting component is put into operation (411).

4. The method according to any one of the preceding claims, comprising: The fluid-conducting component (24) is shut down (413), wherein dry compressed air (L T ) The blowing step (419) is started in time after the stopping of operation (413) or simultaneously with the stopping of operation.

5. The method according to any one of the preceding claims, in, The dry compressed air (L T ) The step of blowing (407, 419) is performed for a predetermined flushing duration (t S ), the flushing duration is preferably in the range of 5 seconds or longer, more preferably in the range of 10 seconds or longer, particularly preferably in the range of 15 seconds or longer.

6. A method according to any one of the preceding claims, wherein: The fluid-conducting component (24) has - an expander stage (11) of a compressor assembly (1) of the fuel cell system (100), - an air bearing assembly (9) of a compressor assembly (1) of the fuel cell system (100), - a condensate separator (23) of the fuel cell system (100), and / or - A compressor stage of a compressor assembly (1) of the fuel cell system (100).

7. A method according to any one of the preceding claims, in, The compressed air supply (301) is associated with a pneumatic brake system (300), in particular a multi-circuit brake system, of the vehicle (200).

8. A fuel cell system (100) for driving a vehicle (200), in particular a commercial vehicle, the vehicle having a compressed air supply (301) independent of the fuel cell system (100), the compressed air supply being configured to provide dry compressed air (L T ),in, The fuel cell system (100) comprises: A cathode-side flow path (16) connected to the environment (U) in a fluid-conducting manner, the cathode-side flow path is used to convey air from the environment (U) to the fuel cell system and to convey cathode exhaust gas (L K ) is delivered from the fuel cell system to the environment (U), and A fluid-conducting component (24) connected to the cathode-side flow path (16) in a fluid-conducting manner, the fluid-conducting component being configured to receive a fluid from air or cathode exhaust gas (L K ) of condensate (K) accumulation, Features The vehicle (200), preferably the fuel cell system (100), has a valve assembly (25) that can be switched back and forth between a blocking position (S) and a release position (F), wherein the valve assembly (25) is connected to the flow path (16) on the cathode side in a fluid-conducting manner in the release position (F) and is configured to, in the release position (F), transfer dry compressed air (L T ) is blown into the flow path (16) on the cathode side, and is connected to the flow path (16), so that the fluid-guiding component (24) is dried by the compressed air (L T ) flows through, and the existing air (L) or the existing cathode exhaust gas (L K ) and / or condensate (K) are thereby displaced from the fluid-conducting component (24) in the direction of the environment (U).

9. The fuel cell system (100) according to claim 8, It is characterized in that The valve module (25) is controllable and is designed to be connected to a control unit (305) in a signal-conducting manner, wherein the control unit (305) is preferably designed as a brake control unit or trailer brake control unit.

10. A vehicle (200), in particular a commercial vehicle, comprising: The fuel cell system (100) according to claim 9, and A controller (305) is connected to the valve assembly (25) in a signal transmission manner and is configured to control the valve assembly (25) in the method according to any one of claims 1 to 7 to transfer the dry compressed air (L T ) is blown in, where The control unit (305) is preferably designed as a brake control unit or a trailer brake control unit.

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