Gas conducting device for delivering a reactant gas into a fuel cell system and for separating any liquid components from the reactant gas

Abstract

The invention relates to a gas conducting device for delivering a reactant gas into a fuel cell system (9) and for separating any liquid components (10) from the reactant gas, wherein the gas conducting device comprises: a gas inlet (3) and a gas outlet (7) and a gas transport channel (2) that extends therebetween and is configured to conduct the reactant gas, when it is fed in at the gas inlet (3), from there as a reactant gas flow (4) to the gas outlet (7) in order to supply the reactant gas to one or more fuel cells or fuel cell stacks (8) of the fuel cell system (9), which fuel cells or fuel cell stacks can be connected to the gas outlet (7); and a liquid outlet (5), different from the gas outlet (7), on the gas transport channel (2); wherein the gas transport channel (2) is additionally designed in such a way as a liquid separator for separating liquid components (10) from the reactant gas flow (4) that the geometry thereof defines a gas conducting path (11), for guiding the reactant gas flow (4) from the gas inlet (3) to the gas outlet (7), such that the gas conducting path (11) has a change of direction (12), and the geometry further defines a liquid conducting path (13), for guiding any liquid components (10) entrained in the gas flow to the liquid outlet (5), such that the gas conducting path (11) and the liquid conducting path (13) separate from one another at the location of the change of direction (12) of the gas conducting path (11) in such a way that the liquid conducting path (13) has no change of direction (12) there or only a smaller change of direction than the gas conducting path.

Description

[0001] 120703P1348PC / 2024P025

[0002] Gas supply device for feeding a reactant gas into a fuel cell system and for separating any liquid components from the reactant gas

[0003] The present invention relates to a gas guidance device for supplying a reactant gas to a fuel cell system and for separating any liquid components from the reactant gas, as well as a fuel cell system equipped with at least one such gas guidance device.

[0004] Fuel cell systems (FCS) are a well-known method for providing energy supply systems that deliver electrical energy electrochemically. In particular, the use of fuel cell systems for the environmentally friendly electrical power supply of electric or hybrid vehicles has long been recognized as a possibility and has already been implemented by various vehicle manufacturers. Stationary fuel cell systems for environmentally friendly local energy generation, for example for powering buildings or other infrastructure, are also known.

[0005] For operation, a fuel cell system must be supplied on the anode side with a suitable, usually gaseous, fuel as the first reactant, and on the cathode side with a suitable, usually also gaseous, oxidizer as the second reactant, in order to maintain the intended chemical reaction in the fuel cells of the fuel cell system, converting the reactants and releasing usable electrical energy. A fuel cell system can thus be considered an energy conversion system designed to convert at least a portion of the chemical reaction energy of the supplied fuel and the oxidizer into electrical energy. Many well-known fuel cell systems use hydrogen-oxygen fuel cells, i.e.,Fuel cells are designed to use hydrogen as fuel and oxygen or air as an oxidizer, although in the case of air, the oxygen it contains is crucial for proper oxidation. Certain fuel cell types can use other fuels instead of hydrogen, particularly methanol, butane, or natural gas.

[0006] By its very nature, a fuel cell system is also a thermal system, which is subject to significant temperature fluctuations due to both the chemical reactions occurring within its fuel cells and external influences. Due to the design of the fuel cell system, it is usually impossible to completely prevent a reaction product formed on the cathode side, particularly water (H₂O) in liquid or vapor form, from diffusing partially to the anode side. Furthermore, if an anode-side fuel recirculation system uses fuel mixed with liquid or vapor components (especially H₂O), incompletely consumed fuel from the fuel cell anodes can circulate back to a supply of fresh, usually "dry," fuel. This means that such components may be present as an admixture in the fuel gas stream subsequently supplied to the anodes.

[0007] The problem here is that when the fuel cell system cools down, especially after being switched off, particularly at cold temperatures such as in winter, vapor components present in the fuel cell system, especially water vapor, can condense. The liquid formed during condensation can then enter the gas supply channels intended for fuel delivery and collect there, for example, in the form of drops, puddles, or large films (120703P1348PC / 2024P025). During subsequent operation, especially a cold start or even a start from freezing, there is a risk that the liquid will be carried (especially blown) into the fuel cells by the gas flow forming in the respective gas supply channel.There, it can lead to blockages, especially of gas channels, such as fine gas channels on the bipolar plates of PEM fuel cells, and consequently to reduced performance or even damage, such as corrosion, in such affected fuel cells.

[0008] It is an object of the present invention to address one or more of the problems mentioned above. In particular, it aims to prevent the unwanted ingress of liquid from gas supply channels into the fuel cells of the fuel cell system.

[0009] To solve this problem, a gas supply device and a fuel cell system are proposed according to the teaching of the independent claims. Various embodiments and further developments of the solution are the subject of the dependent claims.

[0010] terms

[0011] Some of the terms used herein to describe the present solution are explained in more detail below:

[0012] The term "liquid," as used herein, refers to matter in a liquid state. This includes, in particular, small bodies of liquid, such as liquid droplets like water droplets.

[0013] The term "gas conveying device," as used herein, refers to a device configured to convey gas from one location to another along a defined transport path, in particular with substantially no gas loss. For this purpose, a gas conveying device may include a gas transport channel, in particular a tube- or hose-like channel, from which the gas to be conveyed can escape substantially only at one or more designated gas outlets.

[0014] The term "reactant gas," as used herein, refers to a gas that contains, or even essentially consists of, a reactant for the substance used in the fuel cell system for electrochemical energy conversion. Specifically, in a hydrogen-oxygen fuel cell, hydrogen gas (H2) as fuel constitutes a first reactant gas, and gaseous oxygen (O2) in pure form or as a component of air constitutes a second reactant gas for electrochemical energy conversion.

[0015] The term "reactant gas flow", as used herein, refers to a mass flow formed at least partially by a reactant gas flowing along a transport path.

[0016] The term "gas transport channel," as used herein, refers to a structure, particularly a tubular or hose-shaped one, configured to convey gas from one location to another along a defined transport path, especially with substantially no gas loss. A gas conveying device thus regularly comprises one or more gas transport channels for guiding a gas to be transported.

[0017] The term "change of direction," as used herein, refers to a change in direction along a real or imagined line, i.e., at least a local deviation from a linear path. The magnitude of a change of direction can be defined, in particular, by the angle between the initial direction of the line 120703P1348PC / 2024P025 immediately before the change of direction and the final direction of the line after the change of direction has occurred. For example, if a line bends orthogonally at a certain point, forming a kink or curve, the magnitude of the change of direction can be expressed as 90° or TT / 2.

[0018] The term "path," as used herein, refers to an imaginary (i.e., virtual) line that characterizes the course of a mass flow or a channel for conveying a mass flow. In particular, the path can be defined as a line extending along the course of the channel, such as a gas or liquid transport channel, at its center.

[0019] The term "gas guidance path", as used herein, refers to a path along which a mass flow consisting at least partially, and in particular predominantly, of gas is guided.

[0020] The term "liquid guidance path" refers to a path along which a mass flow consisting at least partially, and in particular predominantly, of liquid is guided.

[0021] The term "siphon," as used herein, refers to a depression, for example a "V"-shaped or "U"-shaped depression, in a pipe-like channel. Since the depression defines at least a locally lowest point in the channel, liquid can collect there—at least in the absence of sufficiently opposing forces beyond gravity, such as sufficiently strong suction or pressure forces.

[0022] Any terms used herein, such as "includes," "contains," "includes," "indicates," "has," "with," or any other variant thereof, are intended to cover non-exclusive inclusion. For example, 120703P1348PC / 2024P025

[0023] A method or apparatus comprising or featuring a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent in such a method or apparatus.

[0024] Furthermore, unless explicitly stated otherwise, "or" refers to an inclusive "or" and not an exclusive "or". For example, a condition A or B is satisfied by one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0025] The terms "ein" or "eine," as used here, are defined as "one or more." The terms "ein anderer" and "ein Weitere," as well as any other variant thereof, are to be understood as "at least one more."

[0026] The term "plural", as it may be used here, is to be understood in the sense of "two or more".

[0027] The terms “first”, “second”, “third”, and similar terms in the description and in the claims are used to distinguish between similar or otherwise identically named elements and not necessarily to describe a sequential, spatial, or chronological order. It is understood that the terms used in this way are interchangeable under suitable circumstances and that the embodiments of the solution described herein may also function in orders other than those described or illustrated here. 120703P1348PC / 2024P025

[0028] The terms "configured" or "set up" to perform a specific function (and their respective variations), as used here, mean that a device or component thereof already exists in a configuration or setting capable of performing the function, or at least is adjustable—i.e., configurable—so that it can perform the function after appropriate adjustment. Configuration can be achieved, for example, by adjusting process parameters or by using switches or similar devices to activate or deactivate functionalities or settings. In particular, the device may have several predefined configurations or operating modes, allowing configuration by selecting one of these.

[0029] A first aspect of the solution presented here concerns a gas supply device for feeding a reactant gas into a fuel cell system and for separating any liquid components from the reactant gas. The gas supply device comprises:

[0030] (i) a gas inlet and a gas outlet and an intervening gas transport channel configured to carry the reactant gas, when fed into the gas inlet, from there as a reactant gas stream to the gas outlet in order to supply one or more fuel cells or fuel cell stacks of the fuel cell system connectable to the gas outlet with the reactant gas; and

[0031] (ii) a liquid outlet on the gas transport channel that is different from the gas outlet.

[0032] The gas transport channel is also designed as a liquid separator, such that its geometry 120703P1348PC / 2024P025

[0033] - firstly, the gas flow path for directing the reactant gas flow from the gas inlet to the gas outlet is defined in such a way that the gas flow path has a change of direction, and

[0034] - secondly, a liquid guidance path for directing any liquid components carried in the gas stream to the liquid outlet is defined in such a way that the gas guidance path and the liquid guidance path separate from each other at the point of change of direction of the gas guidance path in such a way that the liquid guidance path has no change of direction there or only a smaller change of direction than the gas guidance path.

[0035] The gas supply device can thus, in addition to its primary task of supplying the reactant gas stream to the fuel cell(s), simultaneously fulfill another task as a liquid separator, at least partially separating liquid components carried along with the reactant gas stream, so that the separated amount of liquid cannot enter the fuel cell(s) together with the reactant and thus the problems mentioned at the beginning are addressed.

[0036] The principle behind liquid separation is based on the fact that the liquid components, such as water droplets, regularly have a greater particle mass (e.g., water droplet mass) than the fuel particles (e.g., H2 molecules). Due to the resulting difference in inertia, the heavier liquid components, at comparable speeds (approximately the gas flow velocity), can no longer follow the gas flow path, at least partially, in the area where the direction of the gas flow changes. Instead, they enter the liquid guide path leading to the liquid outlet.Figuratively speaking, this can also be expressed as follows: in the area of ​​the change of direction, the reactant gas stream, as a gas, can follow the "curve" defined by the change of direction to the gas outlet due to its lower inertia, while the heavier liquid, due to its liquid state and greater inertia, "flies out of the curve" and therefore "flies" through the gas outlet.

[0037] This results in an inertial separation of liquid components from the reactant gas stream, allowing the separated liquid components to be discharged from the fuel cell system, bypassing the fuel cells. Furthermore, the liquid separator operates purely passively and requires no separate energy supply for the separation process.

[0038] In some embodiments, the gas flow device further comprises a reactant discharge channel configured to discharge the depleted reactant flowing out of the at least one fuel cell during operation of the fuel cell system. The liquid outlet is fluidly connected to the reactant discharge channel via a bypass channel. This creates a bypass that bridges the fuel cell(s), through which the liquid separated from the reactant flowing towards the fuel cells via the liquid outlet is discharged by being mixed with the depleted reactant stream coming from the fuel cell(s). This mixing advantageously takes place at a location from which the depleted reactant stream is not (or no longer) potentially recirculated back to the fuel cell(s), as otherwise a renewed introduction of liquid would be a concern.This is particularly relevant for the anode side. The bypass allows the liquid separated from the reactant gas stream to be efficiently removed from the fuel cell system using an existing reactant discharge channel that is independent of the bypass.

[0039] In some embodiments, the bypass channel has a collection area spaced apart from both ends of the bypass channel, which is designed as a siphon for collecting liquid occurring in the bypass channel. This can be advantageously used to prevent the possible collection of 120703P1348PC / 2024P025

[0040] The aim is to focus or even restrict the liquid in the bypass channel to a location spaced apart from both ends of the bypass channel, the collection area, so that in the event of freezing of the collected liquid, no damage to the end connections of the bypass channel, such as connectors, to the gas outlet or to the reactant removal channel is to be feared.

[0041] In some embodiments, the gas guide device also includes a heating device for heating the bypass channel. This prevents the freezing of any liquid collected in the bypass channel, thus avoiding unwanted blockages and a potential source of ice clumps that could lead to blockages or damage further downstream in the bypass channel or the reactant discharge channel. The heating device can be integrated into the bypass channel or designed as a surrounding sleeve (heating sleeve).

[0042] In some embodiments, the bypass channel includes at least one flow restrictor to reduce or limit the flow velocity of a fluid flow occurring in the bypass channel during operation of the fuel cell system. This allows for the targeted limitation of reactant loss for energy conversion in the fuel cell(s) caused by the fluid flow in the bypass channel, particularly in such a way as to achieve an optimal compromise between effectively separating liquid components from the reactant gas and the resulting loss of reactant gas. The type, geometry, and position of the flow restrictor(s) can be determined, especially during the design of the fuel cell system, by means of simulation or within the framework of test series. 120703P1348PC / 2024P025

[0043] In some embodiments, the gas transport channel further features one or more liquid separators in the area of ​​the gas flow path, each configured to drain any liquid accumulations occurring in the gas transport channel. This is therefore an additional design measure aimed at preventing or at least reducing liquid accumulations in the gas transport channel, particularly those occurring upstream of the liquid outlet.

[0044] For this purpose, the liquid separator, or at least one, can be connected to the bypass channel, particularly via a fluid-conducting connection, to drain the liquid it collects. In this case, the bypass channel can thus efficiently fulfill another function as a combined discharge channel for liquid that is to be separated from the gas transport channel by the liquid separator or by the liquid separator, bypassing the fuel cell^).

[0045] In some embodiments, the liquid separator, or at least one of it, has a groove and / or orifice arranged on the inner wall of the gas transport channel. The groove or orifice can thus act as a barrier, particularly for any liquid that collects in the gas transport channel. Especially during starting, particularly during cold or freezing starts, of the fuel cell system, the previously collected liquid can be driven by the now occurring reactant gas flow and accumulate in the groove or in front of the orifice, and from there be discharged from the gas transport channel through one or more discharge openings in its inner wall.

[0046] The groove or orifice can be designed, in particular, as an annular groove or orifice running along the inner wall of the gas flow channel. This allows for, especially during startup or operation of the 120703P1348PC / 2024P025

[0047] Fuel cell systems can also collect and separate liquid components at the groove or aperture that may occur not (only) at the bottom of the gas transport channel, but at other points on its inner wall, due to the reactant gas flow or other influences, such as accelerations to which the fuel cell system may be subjected in automotive applications.

[0048] In some embodiments, at least one liquid separator is arranged along the gas flow path originating from the gas inlet, upstream of the gas outlet or, if the outlet has multiple outlet openings, upstream of the gas outlet opening closest to the gas inlet. This allows liquid to be separated from the gas flow even before the (first) outlet opening, thus effectively reducing the amount of liquid that might still pass through the outlet.

[0049] In some embodiments, the gas transport channel is designed as a common-rail channel and features multiple gas outlet openings located at various points along the gas flow path, which together form the gas outlet. The gas outlet openings are configured to simultaneously supply a corresponding number of fuel cells or fuel cell stacks of the fuel cell system with a proportionate share of the reactant gas stream. This allows not only for the space-saving supply of reactants to all fuel cells or fuel cell stacks using a single gas transport channel, but also for the standardized removal of liquid components from the reactant gas stream.

[0050] In some embodiments, the geometry of the gas transport channel is defined such that its inner wall is at least in one area between 120703P1348PC / 2024P025

[0051] The section between the gas inlet and the gas outlet has a smooth, edgeless inner wall. An edge would increase the likelihood of liquid adhering to it over a longer period and thus to the inner wall. The absence of edges, on the other hand, facilitates the drainage of any liquid that may accumulate on the inner wall. During operation of the fuel cell system, the liquid can thus flow with the reactant gas stream along the gas path until its direction changes, and from there along the liquid path to the liquid outlet. Alternatively, particularly when the fuel cell system is switched off or operating at low power, it can drain well to the bottom of the gas transport channel, where it can be separated from the gas transport channel, especially by one of the aforementioned liquid separators.

[0052] In some embodiments, the gas guide device is at least partially integrated into a media distribution plate for the fuel cell system. This allows the supply of the reactant gas, including the separation of any liquid components, to be combined with the supply of one or more other media, in particular coolant for cooling the fuel cell(s), in a space-saving, integrated manner.

[0053] In some embodiments, the gas supply device is configured for the anode-side supply of a gaseous fuel as a reactant into the fuel cell system. Accordingly, the gas supply device can be used to supply one of the fuels to the fuel cell(s), such as hydrogen gas (H2), including the separation of any liquid components from it.

[0054] In some embodiments, the gas supply device is configured for the cathode-side supply of a gaseous oxidizing agent as a reactant into the fuel cell system. Accordingly, the gas supply device (120703P1348PC / 2024P025) can be used to supply an oxidizing agent to the fuel cell(s), such as air or oxygen gas (O2), including the separation of any liquid components.

[0055] A second aspect of the solution presented here concerns a fuel cell system. It comprises one or more fuel cells or fuel cell stacks, and, for supplying at least one reactant gas to them, a gas supply device according to the first aspect, located on the anode side and / or cathode side. The fuel cell system is configured to discharge liquid components leaving the associated gas transport channel through the respective liquid outlet of each gas supply device, bypassing the fuel cells of the fuel cell system. Thus, a combination of both an anode-side and a cathode-side gas supply device is possible within the fuel cell system, allowing the advantages of both to be utilized.It has one or more fuel cells or fuel cell stacks and, for supplying at least one reactant gas to them, a gas supply device according to the first aspect on both the anode and / or cathode side. The fuel cell system is configured to discharge liquid components leaving the associated gas transport channel through the respective liquid outlet of each gas supply device, bypassing the fuel cells of the fuel cell system. Thus, a combination of both an anode-side and a cathode-side gas supply device is particularly possible in the fuel cell system, allowing the advantages of both to be utilized. 120703P1348PC / 2024P025.

[0056] In some embodiments, the fuel cell system has a gas guide device according to the first aspect on both the anode and cathode sides, wherein, in a section extending upwards from the respective point of change of direction in a reactant gas stream, the gas transport channel of the anode-side gas guide device has a smaller cross-sectional area than the gas transport channel of the cathode-side gas guide device. This design is particularly advantageous for fuel cell types in which the gaseous fuel exhibits better, and especially better laminar, flow properties than the gaseous oxidizer under the same pressure and temperature conditions. Thus, the smaller channel cross-section on the anode side, and therefore a smaller installation space in the fuel cell system, is sufficient to accommodate the gas flow.to supply the fuel cells with an amount of fuel gas sufficient for the chemical reaction of the amount of oxidizing agent supplied simultaneously on the cathode side in the fuel cell(s).

[0057] In some embodiments, the fuel cell system includes a gas flow control device for generating, controlling, or regulating the reactant gas flow through the gas transport channel. This device is configured to impart an average flow velocity of at least 10 m / s to the reactant gas flow at the point of change of direction during operation of the fuel cell system. It has been found that at or above this flow velocity value, the inertia-based separation of liquid, particularly water, from the reactant gas flow by the liquid separator can be achieved particularly effectively and reliably.

[0058] In some embodiments, the fuel cell system is configured such that, at least during idling operation, where it generates only a minimal mass flow rate of the reactant gas stream along the gas path within its target operating range, at most 3%, in particular at most 2%, or even at most 1% of the reactant gas stream by volume leaves the gas transport channel through the liquid outlet. This allows for a particularly good compromise between the requirements of effectively removing liquid from the reactant gas stream on the one hand, and minimizing the amount of reactant gas bypassing the fuel cell(s) on the other.

[0059] The solution will be explained in more detail below using figures that merely illustrate exemplary implementations. The figures show

[0060] Fig. 1 shows an exemplary embodiment of a gas guidance device,

[0061] Fig. 2 schematically shows a fuel cell system in a side sectional view with a bottom-side media distribution plate, into which a gas guidance device, in particular according to Fig. 1, is integrated on the anode side and / or cathode side, and

[0062] Fig. 3 schematically shows a side view of a fuel cell system according to an exemplary embodiment.

[0063] Figure 1 schematically illustrates an exemplary embodiment of a gas supply device 1. It can be used on the anode side and thus for fuel supply, or on the cathode side for supplying the oxidizing agent, each in gaseous form. Fuel and oxidizing agent are collectively referred to here as the "reactant".

[0064] The gas guide device 1 has a gas transport channel 2 designed as a tube, which extends between a gas inlet 3 at a first end 120703P1348PC / 2024P025 of the tube for introducing a reactant gas stream 4 and a liquid outlet 5 for discharging liquid at the opposite end of the tube. In this example, two gas outlet openings 6, collectively referred to as gas outlets 7, are located on the tube wall of the gas transport channel 2 between the gas inlet 3 and the liquid outlet 5. Each of the gas outlet openings 6 serves to be fluidly connected to a fuel cell, in practice usually to an entire fuel cell stack 8 consisting of a plurality of fuel cells, so that during operation of the fuel cell system 9, the fuel cells can be supplied with the reactant from the reactant gas stream 4 through the gas outlet opening 6.Instead of the two fuel stacks shown, the fuel cell system 9 can also have a different number of fuel stacks, in particular only one or three fuel stacks. The number of gas outlet openings 6 is then adjusted accordingly. In the case of more than one fuel cell stack 8 connected to the gas transport channel 2, the gas transport channel 2 can be referred to as a common-rail channel, since several fuel stacks then share the same gas transport channel 2 for reactant supply.

[0065] In practice, during the operation of the fuel cell system 9, the reactant gas stream 4 may carry not only the reactant itself, but also liquid components 10, such as water droplets. The reactant gas stream 4, which enters the gas transport channel 2 through the gas inlet 3, initially moves on average along a gas flow path 11 defined by the geometry of the tubular gas transport channel 2 towards the liquid outlet 5. Upon reaching the gas outlet 7, the reactant, due to its gaseous state and gas pressure, can reach the gas outlet openings 6 and from there enter the respective connected fuel cell stacks 8. In this sense, the gas stream thus undergoes, on average, at least a partial change of direction 12.The strength of the change of direction 12 can be defined as the angle > 120703P1348PC / 2024P025 by which the average direction of the reactant gas stream 4 changes on its way from the gas inlet 3 to the respective gas outlet opening 6.

[0066] The liquid components 10 carried in the reactant gas stream 4 regularly have a significantly larger mass than the gas particles of the reactant. Therefore, at a sufficiently high flow velocity of the reactant gas stream 4, which is advantageously at or above 10 m / s, they cannot follow the change of direction 12. Instead, at the point of the change of direction 12, they leave the gas flow path, at least partially, ideally predominantly, and instead, due to inertia, follow a liquid flow path 13, which separates from the gas flow path 11, to the liquid outlet 5. Because of its geometry described above, the gas transport channel 2 thus acts as a liquid separator for at least partially separating liquid components 10 from the reactant gas stream 4.

[0067] The liquid outlet 5 is connected via a channel bridging the fuel cell stack(s) 8, referred to here as bypass channel 14, to a reactant discharge channel 15 of the gas supply device 1. This channel is designed to discharge the reactant gas 16 emerging from the fuel stack(s) and depleted there due to the electrochemical reaction. Through the bypass channel 14, the liquid components 10 of the original reactant gas stream 4 exiting the liquid outlet 5 from the gas transport channel 2 can thus enter the reactant discharge channel 15 and from there, together with the depleted reactant gas 16, be discharged from the fuel cell system 9 as reactant discharge 17.

[0068] Additionally, one or more liquid separators can be arranged in or on the gas transport channel 2. Their primary function is to discharge liquid accumulations 18, such as those occurring due to condensation of moisture in the gas transport channel 2, directly and without having to pass through the liquid outlet 5 at the end of the gas transport channel 2. Such a liquid separator can, in particular, have an orifice 19 or groove 20 arranged on the inner wall of the gas transport channel 2, which acts as a barrier for the liquid accumulation 18 and ensures that the liquid drains into a discharge channel branching off from the gas transport channel 2. In Fig. 1, an orifice 19 and a groove 20 (dashed lines) are shown simultaneously for better illustration. Both can be used either individually or in combination.

[0069] The discharge channel can, for example, lead into the bypass channel 14 to dispose of the draining liquid there. The orifice 19 or groove 20 can, in particular, be designed as an annular orifice or annular groove around the inner wall of the gas transport channel 2, so that liquid components 10, especially liquid films, that have settled above the bottom of the gas transport channel 2 can be specifically drained away. The barrier effect of the orifice 19 or groove 20 is particularly relevant when starting the fuel cell system 9, when the resulting reactant gas flow 4 drives the liquid accumulation 18 towards the orifice 19 or groove 20.

[0070] Fig. 2 schematically shows an exemplary embodiment of a fuel cell system 9 in a side sectional view, with a media distribution plate on the bottom side into which a gas guide device 1, in particular according to Fig. 1, is integrated on the anode side and / or cathode side. The fuel cell system 9 has a housing 21 in which both the fuel cells in one or (as shown) several fuel cell stacks 8 and the media distribution plate with the gas guide device(s) 1 are arranged. The fuel cell system 9 can include further components that are known in principle to those skilled in the art. 120703P1348PC / 2024P025

[0071] Fig. 3 schematically shows a side view of a fuel cell system 9 according to an exemplary embodiment, such as the fuel cell system 9 from Fig. 2. In the fuel cell system 9, a gas guide device 1, such as that shown in Fig. 1, is installed on both the anode and cathode sides. Thus, on the inlet side, there is an anode-side gas inlet 3 and a cathode-side gas inlet 3 leading into respective gas transport channels 2. The same applies accordingly to the reactant discharge channels 22 downstream of the fuel cell stacks 8 with respect to gas flow. In the illustration of Fig. 3, the upper channels are assigned to the anode side and the lower channels to the cathode side, and each has a smooth, circular cross-section. Due to the better flow properties of hydrogen as the fuel used here, the cross-sectional areas can be, as shown,Due to the circular symmetry, the diameters of the cross-sections on the anode side can be optionally smaller than those on the cathode side.

[0072] Between the respective liquid outlet 5 and the associated reactant discharge channel 15 on the anode and cathode sides, respectively, runs a bypass channel 14, which is shaped such that it has a collection area 23 between its ends, usable as a siphon for liquid. Should a liquid accumulation 18 occur in the bypass channel 14, for example during the cooling of the fuel cell system 9, it will thus be located predominantly in the collection area 23 and therefore away from the ends and any connectors that may be located there.

[0073] Furthermore, as shown, a heating device 24 may be provided for heating the bypass channels 14, particularly for the purpose of preventing or dissolving ice formation. It may be integrated into the bypass channel 14, for example into its wall, or be designed as a heating sleeve that at least partially surrounds it. 120703P1348PC / 2024P025

[0074] Finally, flow restrictors 25 may also be present in each of the bypass channels 14, which can serve in particular to limit the flow rate of gas through the respective bypass.

[0075] While at least one exemplary embodiment has been described above, it should be noted that a large number of variations exist. It should also be noted that the described exemplary embodiments are merely non-limiting examples, and it is not intended to restrict the scope, applicability, or configuration of the systems, devices, and methods described herein. Rather, the preceding description will provide the person skilled in the art with guidance for implementing at least one exemplary embodiment. It is understood that various modifications to the function and arrangement of the elements described in an exemplary embodiment can be made without deviating from the subject matter defined in the appended claims.

[0076] 120703P1348PC / 2024P025

[0077] Reference symbol list

[0078] 1 Gas guide device

[0079] 2 Gas transport canal

[0080] 3 Gas inlet

[0081] 4 Reactant gas stream

[0082] 5. Liquid outlet

[0083] 6 gas outlet openings

[0084] 7 Gas outlet

[0085] 8 fuel cell stacks

[0086] 9 Fuel cell system

[0087] 10 liquid components

[0088] 11 Gas routing path

[0089] 12 changes of direction

[0090] 13 Fluid guidance path

[0091] 14 Bypass channel

[0092] 15 reactant removal channel

[0093] 16 depleted reactant

[0094] 17 Reactant stream

[0095] 18 fluid accumulations

[0096] 19 aperture

[0097] 20 Nut

[0098] 21 cases

[0099] 22 reactant removal channels

[0100] 23 Collection area

[0101] 24 Heating device

[0102] 25 flow restrictors

[0103] 26 Media distribution panel

[0104] 27 Gas flow control device

[0105] □ Angle

Claims

120703P1348PC / 2024P025 Patentansprüche 1. Gas supply device for supplying a reactant gas to a fuel cell system (9) and for separating any liquid components (10) from the reactant gas, the gas supply device comprising: a gas inlet (3) and a gas outlet (7) and an intermediate gas transport channel (2) configured to direct the reactant gas, when fed into the gas inlet (3), from there as a reactant gas stream (4) to the gas outlet (7) in order to supply one or more fuel cells or fuel cell stacks (8) of the fuel cell system (9) connectable to the gas outlet (7) with the reactant gas; and a liquid outlet (5) on the gas transport channel (2) separate from the gas outlet (7);wherein the gas transport channel (2) is also designed as a liquid separator for separating liquid components (10) from the reactant gas stream (4) such that its geometry defines a gas guidance path (11) for guiding the reactant gas stream (4) from the gas inlet (3) to the gas outlet (7) such that the gas guidance path (11) has a change of direction (12), and the geometry further defines a liquid guidance path (13) for guiding any liquid components (10) carried in the gas stream to the liquid outlet (5) such that the gas guidance path (11) and the liquid guidance path (13) separate from each other at the location of the change of direction (12) of the gas guidance path (11) such that the liquid guidance path (13) has no change of direction (12) there or only a smaller change of direction (12) than the gas guidance path. 120703P1348PC / 2024P025 2. Gas guidance device according to claim 1, wherein the gas guidance device (1) further comprises a reactant discharge channel (15) configured to discharge the depleted reactant (16) flowing out of the at least one fuel cell during operation of the fuel cell system (9); and the liquid outlet (5) is fluidly connected to the reactant discharge channel (15) via a bypass channel (14).

3. Gas guiding device according to claim 2, wherein the bypass channel (14) has a collection area (23) spaced apart from the two ends of the bypass channel (14), which is designed as a siphon for collecting liquid occurring in the bypass channel (14).

4. Gas guiding device according to claim 2 or 3, further comprising a heating device (24) for heating the bypass channel (14).

5. Gas guidance device according to one of claims 2 to 4, wherein the bypass channel (14) has at least one flow limiter (25) for reducing or limiting a flow velocity of a fluid flow occurring in the bypass channel (14) during operation of the fuel cell system (9).

6. Gas guidance device according to one of the preceding claims, wherein in the gas transport channel (2) one or more liquid separators are further arranged in the area of ​​the gas guidance path (11), each configured to drain liquid accumulations (18) occurring in the gas transport channel (2) from the gas transport channel (2). 120703P1348PC / 2024P025 7. Gas guiding device according to claim 6, in combination with one of claims 2 to 5 wherein the or at least one liquid separator for draining the liquid collected by it is fluidly connected to the bypass channel.

8. Gas guiding device according to claim 6 or 7, wherein the or at least one liquid separator has a groove (20) and / or aperture (19) arranged on the inner wall of the gas transport channel (2).

9. Gas guiding device according to claim 8, wherein the groove (20) or aperture (19) is designed as an annular groove or annular aperture circumferential along the inner wall of the gas guiding channel.

10. Gas guiding device according to one of claims 6 to 9, wherein at least one liquid separator is arranged along the course of the gas guiding path (11) starting from the gas inlet (3) in the reactant gas stream upstream of the gas outlet (7) or, if the latter has several gas outlet openings (6), in the reactant gas stream upstream of the gas outlet opening (6) of the gas outlet (7) that is closest to the gas inlet (3).

11. Gas guidance device according to one of the preceding claims, wherein the gas transport channel (2) is designed as a common-rail channel and for this purpose has a plurality of gas outlet openings (6) adjacent to the gas guidance path (11) at different locations, which together form the gas outlet (7) and are configured to supply a number of fuel cells or fuel cell stacks (8) of the fuel cell system (9) corresponding to their number simultaneously with the reactant gas stream (4). 120703P1348PC / 2024P025 12. Gas guiding device according to one of the preceding claims, wherein the geometry of the gas transport channel (2) is defined such that its inner wall has an edge-free inner wall at least in a section located between the gas inlet (3) and the gas outlet (7).

13. Gas guidance device according to one of the preceding claims, wherein the gas guidance device (1 ) is at least partially integrated into a media distribution plate (26) for the fuel cell system (9).

14. Gas supply device according to one of the preceding claims, wherein the gas supply device (1 ) is configured for supplying a gaseous fuel as a reactant to the fuel cell system (9) on the anode side.

15. Gas supply device according to one of claims 1 to 11, wherein the gas supply device (1) is configured for supplying a gaseous oxidizing agent as a reactant to the fuel cell system (9) on the cathode side.

16. Fuel cell system (2), comprising one or more fuel cells or fuel cell stacks (8) and a gas supply device (1) according to claim 11 on the anode side and / or a gas supply device (1) according to claim 12 on the cathode side for supplying at least one reactant gas thereto; wherein the fuel cell system (9) is configured to discharge liquid components (10) leaving the associated gas transport channel (2) through the respective liquid outlet (5) of each gas supply device from the fuel cell system (9) bypassing the fuel cells of the fuel cell system (9). 120703P1348PC / 2024P025 17. Fuel cell system (2) according to claim 14, comprising both an anode-side gas guidance device (1) according to claim 11 and a cathode-side gas guidance device (1) according to claim 1, wherein in a section extending upwards from the respective location of the change of direction (12) in a reactant gas stream, the gas transport channel (2) of the anode-side gas guidance device (1) has a smaller cross-sectional area than the gas transport channel (2) of the cathode-side gas guidance device (1).

18. Fuel cell system (2) according to claim 14 or 15, wherein the fuel cell system (9) has a gas flow control device (27) for generating, controlling or regulating the reactant gas flow (4) flowing through the gas transport channel (2), which is configured to give the reactant gas flow (4) an average flow velocity at the point of change of direction (12) of at least 10 m / s when the fuel cell system (9) is in operation.

19. Fuel cell system (2) according to one of claims 16 to 18, wherein the fuel cell system (9) is configured such that, during its operation, at least in the case of idle operation, in which it generates only a minimal mass flow rate of the reactant gas stream (4) along the gas guide path (11) within its target operating range, at most 3%, in particular at most 2% or even at most 1% of the reactant gas stream (4) leaves the gas transport channel (2) through the liquid outlet.

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