Fuel cell device and method for manufacturing a fuel cell device

Abstract

Fuel cell device comprising a fuel cell stack (104) in which fuel cell units (132) follow one another along a stacking direction (130), a base body (156) through which a fuel gas and / or an oxidizing agent can be supplied to the fuel cell stack (104), and a seal (154) for sealing between the fuel cell stack (104) and the base body (156), wherein the fuel cell device (100) comprises at least one fluid line (158, 162) which is fluid-tightly connected to the base body (156), extends into an interior of the fuel cell stack (104) and opens into the interior of the fuel cell stack (104) at an outlet opening (160) spaced apart from the seal (154) in the stack direction (130), and wherein the fuel cell stack (104) is detachably fixed to the base body (156), characterized by that at least one fluid line (158, 162) is welded and / or soldered to the base body (156).

Description

[0001] The present invention relates to a fuel cell device comprising a fuel cell stack in which fuel cell units follow one another along a stacking direction, a base body through which a fuel gas and / or an oxidizing agent can be supplied to the fuel cell stack, and a seal for sealing between the fuel cell stack and the base body.

[0002] Known fuel cell devices of this type include the components reformer, fuel cell stack (also referred to as "fuel cell stack"), residual gas burner and stratified heat exchanger.

[0003] In the reformer, a previously vaporized fuel, for example diesel fuel, is broken down into H2, CO, CO2, H2O, and residual hydrocarbons, for instance through partial oxidation of the higher hydrocarbons of the starting fuel. The components H2 and CO can then be electrochemically converted into electricity in the fuel cell stack.

[0004] The fuel gas that remains unused during electrochemical power generation in the fuel cell stack is recombusted in the residual gas burner after the fuel cell stack for safety, environmental, and energy efficiency reasons. The resulting residual heat is fed to the stratified heat exchanger. This heat exchanger uses the process heat to heat the oxidizer (cathode air) for the fuel cell stack before the oxidizer is fed into the fuel cell stack.

[0005] The base body connected to the fuel cell stack, through which the fuel gas and / or the oxidizer are supplied to the fuel cell stack, can, for example, include the residual gas burner and / or the reformer and / or a gas distribution plate.

[0006] To connect the fuel cell stack to the base body, it may be possible, for example, to weld the fuel cell stack directly onto the base body, particularly the residual gas burner. In this case, the initial setup of the fuel cell stack (i.e., the reduction of the electrochemically active cathode-electrolyte-anode units of the fuel cell units in the fuel cell stack and the sintering of the contact pastes) takes place during the first system test of the entire fuel cell device. Only during this initial system test is it possible to assess the functionality of the fuel cell stack. Quality assurance is not possible in this process. Furthermore, directly welding the fuel cell stack onto the base body results in high stresses (welding stresses) which, due to cracking, can cause a total system failure.

[0007] Alternatively, the fuel cell stack can be welded onto a flat plate and then connected to the base body, particularly the residual gas burner, by means of an interposed gasket. In this case, the commissioning of the fuel cell stack and the actual quality assurance (e.g., determining the fuel cell stack's performance data) can be carried out on a conventional fuel cell stack test bench before the fuel cell stack is connected to the base body. However, a potential problem in this case is the possible leakage of fuel gas and / or oxidizer through the gasket between the fuel cell stack and the base body due to a leak in the sealing medium.

[0008] EP 1 038 575 A2 discloses a plate reactor in which reaction channels follow one another along a stacking direction, and a further plate reactor upstream of the plate reactor through which a reaction gas can be supplied to the plate reactor, wherein the plate reactor comprises an insert body which is fluid-tightly connected to the plate reactor, extends into a distribution channel of the plate reactor and opens into the distribution channel of the plate reactor at an outlet opening spaced apart from an inlet opening of the plate reactor in the stacking direction.

[0009] EP 1 450 431 A1 discloses a fuel cell device according to the preamble of claim 1.

[0010] The present invention is based on the objective of creating a fuel cell device of the type mentioned at the outset in which the escape of fuel gas and / or oxidizing agent via the seal between the fuel cell stack and the base body is reduced or completely avoided.

[0011] This problem is solved by a fuel cell device according to claim 1.

[0012] The solution according to the invention is based on the concept of docking the fuel cell stack to the base body by means of a seal which comprises a sealing medium and thereby minimizing the pressure difference between the interior of the fuel cell stack, into which the fuel gas or oxidizing agent flows through the base body, on the one hand and the environment of the fuel cell stack on the other hand in the area of ​​the seal, by introducing the mass flow of the fuel gas or oxidizing agent into the fuel cell stack not directly in the area of ​​the seal, but away from the sealing medium.

[0013] The leakage rate L corresponds to the product of the pressure difference and the volume flow rate of the fuel gas or oxidizing agent and therefore depends linearly on the pressure difference across the seal between the fuel cell stack and the base body.

[0014] When the fuel gas or oxidizer flows into the interior of the fuel cell stack immediately after the seal, the pressure difference there is significantly higher than at the opposite upper end of the fuel cell stack due to the necessary mass flows for supplying the fuel cell stack, since the entire mass flow of the fuel gas or oxidizer is distributed evenly to all fuel cell units in the various successive levels of the fuel cell stack along the stacking direction.

[0015] Through the fluid line provided according to the invention, which extends into the interior of the fuel cell stack, the fuel gas or the oxidizing agent does not enter the interior of the fuel cell stack directly in the area of ​​the seal, but only at the outlet opening of the fluid line, which is spaced away from the seal in the stack direction.

[0016] The pressure of the fuel gas or oxidizer within the fuel cell stack is therefore greatest in the region of this outlet opening and decreases with increasing distance from the outlet opening, from level to level of the fuel cell stack. When the mass flow of the fuel gas or oxidizer reaches the end of the fuel cell stack facing the seal, particularly the lower end of the fuel cell stack, where the sealing medium of the seal is located between the fuel cell stack and the base body, the pressure difference between the interior of the fuel cell stack, especially between a manifold area of ​​the fuel cell stack, and the environment is lowest there, i.e., in the area of ​​the seal. This allows for a lower leakage rate compared to a design without a fluid line, regardless of the sealing medium used.

[0017] In a particular embodiment of the invention, gas-tight tubes can be welded onto the base body, especially the residual gas burner, forming a fluid line that is fluid-tightly connected to the base body. These tubes penetrate the manifold area of ​​the fuel cell stack when the fuel cell stack is docked to the base body. When the fuel cell device is put into operation, the fuel gas or oxidizer flows through the tubes and only enters the manifold area at their outlet openings. From these outlet openings, the fuel gas or oxidizer is then distributed evenly to the various levels of the fuel cell stack, with the pressure decreasing from level to level up to the seal between the fuel cell stack and the base body.

[0018] The invention provides that at least one fluid line is materially bonded to the base body, namely welded and / or soldered.

[0019] To reduce the pressure difference across the seal, it is advantageous if the outlet opening of at least one fluid line has a distance from the seal in the stacking direction that is greater than a quarter, preferably greater than half, of the extent of the fuel cell units of the fuel cell stack in the stacking direction.

[0020] It is particularly advantageous if the outlet opening of at least one fluid line has a distance from the seal in the stacking direction that is greater than 75% of the extent of the fuel cell units of the fuel cell stack in the stacking direction.

[0021] The extension of the fuel cell units of the fuel cell stack in the stacking direction refers to the total extension of all fuel cell units of the fuel cell stack in the stacking direction.

[0022] The further the outlet opening of the fluid line is from the seal in the stacking direction, the lower the pressure difference across the seal, and consequently the lower the leakage rate of the fuel gas or oxidizing agent through the seal.

[0023] In a preferred embodiment of the invention, the outlet opening of at least one fluid line is arranged in a fluid supply channel of the fuel cell stack, wherein the fluid supply channel extends substantially along the stacking direction of the fuel cell stack.

[0024] Furthermore, it may be provided that at least one fluid line comprises a tubular fluid line element.

[0025] The cross-section of the tubular fluid conduit element can, in principle, have any shape, in particular a substantially circular or polygonal shape, for example, a square shape.

[0026] In particular, it may be provided that at least one fluid line is formed in one piece from the tubular fluid line element.

[0027] Furthermore, it is preferably provided that a longitudinal axis of the fluid line element is aligned essentially parallel to the stacking direction of the fuel cell stack.

[0028] The seal between the fuel cell stack and the base body of the fuel cell device may in particular comprise a nonwoven material.

[0029] Preferably, the seal comprises a ceramic nonwoven material. The ceramic nonwoven material can, for example, comprise aluminum oxide fibers and / or zirconium oxide fibers.

[0030] In order to be able to perform a functional test of the fuel cell stack on a fuel cell test bench before the fuel cell stack is connected to the base body, or to be able to replace the fuel cell stack and the base body separately, it is advantageous that the fuel cell stack is detachably fixed to the base body.

[0031] In particular, it may be provided that the fuel cell stack is connected to the base body by means of screws.

[0032] The base body of the fuel cell device, through which fuel gas and / or oxidizing agent is supplied to the fuel cell stack, may in particular comprise a base plate.

[0033] Alternatively or additionally, the base body may include a reformer and / or a residual gas burner of the fuel cell device.

[0034] The fuel cell units of the fuel cell stack of the fuel cell device according to the invention are preferably designed as SOFC (“Solid Oxide Fuel Cell”) fuel cells and / or preferably have an operating temperature of 650 °C or more.

[0035] The fuel gas and / or the oxidizing agent preferably enter the fuel cell stack through the base body at a temperature of at least approximately 650 °C.

[0036] The present invention further relates to a method for manufacturing a fuel cell device.

[0037] The present invention is based on the further objective of creating a method for manufacturing a fuel cell device by which the escape of fuel gas and / or oxidizing agent through a seal between the fuel cell stack and a base body of the fuel cell device during operation of the fuel cell device is reduced or completely avoided.

[0038] This problem is solved by a method for manufacturing a fuel cell device according to claim 13.

[0039] Specific embodiments of such a manufacturing process have already been explained above in connection with the specific embodiments of the fuel cell device according to the invention.

[0040] Further features and advantages of the invention are the subject of the following description and the graphic representation of an exemplary embodiment.

[0041] The drawings show: Fig. 1 a schematic representation of a fuel cell device comprising a reformer, a fuel cell stack, a residual gas burner and a heat exchanger arranged downstream of the residual gas burner; Fig. 2 a schematic vertical section through the fuel cell stack and a gas distribution plate of the fuel cell device Fig. 1; Fig. 3 a schematic top view of the gas distribution plate of the fuel cell device Fig. 1; and Fig. 4 a schematic vertical section through the gas distribution plate Fig. 3 and a fluid-tight fluid line connected to it.

[0042] Identical or functionally equivalent elements are designated with the same reference symbols in all figures.

[0043] One in the Fig. The fuel cell device shown in Figures 1 to 4, designated as a whole by 100, whose basic structure consists of Fig. As can be seen in Figure 1, it comprises a reformer 102, a fuel cell stack 104, a residual gas burner 106 and an exhaust gas heat exchanger 108.

[0044] In the reformer 102, a previously vaporized starting fuel, for example diesel fuel, is converted into a fuel gas which contains electrochemically convertible components, especially H2 and CO, in the fuel cell stack 104.

[0045] The production of the fuel gas from the initial fuel in the Reformer 102 can, for example, be carried out by partial oxidation of the higher hydrocarbons of the initial fuel, such as diesel fuel, by means of which these higher hydrocarbons are broken down into H2, CO, CO2, H2O and residual hydrocarbons.

[0046] The vaporized feedstock is supplied to the reformer 102 via a feedstock supply line 112. The supplied feedstock can be at approximately room temperature.

[0047] For the purpose of carrying out the partial oxidation, air is also supplied to the reformer 102 via an air supply line 114.

[0048] The air supplied to the Reformer 102 can also be at room temperature, for example.

[0049] The partial oxidation of the initial fuel in the reformer 102 generates heat, which heats the fuel gas leaving the reformer 102, also known as reformate, to a temperature of up to approximately 900 °C. This heated fuel gas is supplied to the fuel cell stack 104 via a fuel gas line 116.

[0050] The oxidizing agent required for the electrochemical reaction in the fuel cell stack 104, for example air, is supplied to the cold side of the exhaust gas heat exchanger 108 via an oxidizing agent supply line 118. At the oxidizing agent inlet of the exhaust gas heat exchanger 108, the oxidizing agent can, for example, be at room temperature.

[0051] Exhaust gas from the residual gas burner 106 is supplied to the hot side of the exhaust gas heat exchanger 108 via an exhaust gas line 120. This exhaust gas is generated in the residual gas burner 106 by afterburning the fuel gas that was not completely converted in the fuel cell stack 104.

[0052] The process heat generated in the residual gas burner 106 during the afterburning of the fuel gas is at least partially transferred from the exhaust gas of the residual gas burner 106 to the oxidizing agent in the exhaust gas heat exchanger 108, whereby the exhaust gas is cooled from an inlet temperature of, for example, more than 950 °C to an outlet temperature of, for example, approximately 200 °C.

[0053] The cooled exhaust gas is discharged from the exhaust gas heat exchanger 108 via an exhaust gas discharge line 122.

[0054] The oxidizing agent is heated in the exhaust gas heat exchanger 108, the extent of the heating depending on the operating state of the fuel cell stack 104.

[0055] At the beginning of the heating phase of the fuel cell stack 104, when the fuel cell stack 104 is still cold, the oxidizer exits the exhaust gas heat exchanger 108 at approximately room temperature. During the heating phase of the fuel cell stack 104, the outlet temperature of the oxidizer as it exits the exhaust gas heat exchanger 108 increases and finally reaches, for example, approximately 700 °C when the fuel cell stack 104 is in its operating phase.

[0056] The oxidizing agent heated in the exhaust gas heat exchanger 108 is supplied to the fuel cell stack 104 via an oxidizing agent line 124.

[0057] The electrochemical conversion of the fuel gas and the oxidizing agent takes place in the fuel cell stack 104.

[0058] The fuel gas, which is incompletely converted in the fuel cell stack 104 and has a temperature of, for example, almost 850 °C, passes from a fuel gas outlet of the fuel cell stack 104 via a fuel gas line 126 to a fuel gas inlet of the residual gas burner 106.

[0059] The oxidizing agent, which is incompletely converted in the fuel cell stack 104, passes from the oxidizing agent outlet of the fuel cell stack 104 via an oxidizing agent line 128 to an oxidizing agent inlet of the residual gas burner 106.

[0060] In the residual gas burner 106, the fuel gas is further combusted with the oxidizer, and the resulting exhaust gas from the fuel cell stack 104 is fed to the exhaust gas heat exchanger 108 via the exhaust gas line 120, as described above. This exhaust gas can have a temperature of, for example, approximately 950 °C or more.

[0061] How best to Fig. As can be seen in Figure 2, the fuel cell stack 104 has several fuel cell units 132 arranged successively in a stacking direction 130, each of which comprises an electrochemically active cathode-electrolyte-anode unit with a cathode, an anode, and an electrolyte arranged between the cathode and the anode, as well as an anode compartment adjacent to the anode through which the fuel gas flows, and a cathode compartment 134 adjacent to the cathode through which the oxidizing agent flows. In the schematic representation of the Fig. Figure 2 shows only the cathode compartments 134 of each of the fuel cell units 132. The flow direction of the oxidizer through the fuel cell stack 104 is indicated by the arrows 166.

[0062] In Fig. Figure 2 shows an example of a fuel cell stack 104 with thirteen consecutive fuel cell units 132 arranged in the stacking direction 130. In practice, the number of fuel cell units 132 in the fuel cell stack 104 will be significantly higher.

[0063] The cathode spaces 134 of all fuel cell units 132 are connected via one or more oxidant supply channels 136, preferably running substantially parallel to the stacking direction 130, each with an oxidant passage opening 138 (see Fig. 4) connected in a gas distribution plate 140.

[0064] The oxidizing agent line 124 coming from the exhaust gas heat exchanger 108 opens into the oxidizing agent passage openings 138 in the gas distribution plate 140.

[0065] The oxidizing agent heated in the exhaust gas heat exchanger 108 is thus supplied to the oxidizing agent passage openings 138 in the gas distribution plate 140 via the oxidizing agent line 124.

[0066] The (not shown) anode spaces of all fuel cell units 132 of the fuel cell stack 104 are supplied via one or more fuel gas supply channels 142, preferably running substantially parallel to the stack direction 130 (see Fig. 3) each connected to a fuel gas passage opening 144 in the gas distribution plate 140.

[0067] The fuel gas line 116 coming from the reformer 102 opens into the fuel gas passage openings 144 of the gas distribution plate 140.

[0068] The fuel gas produced in the reformer 102 is thus supplied to the fuel gas passage openings 144 in the gas distribution plate 140 via the fuel gas line 116.

[0069] Furthermore, the cathode spaces 134 of all fuel cell units 132 are connected to an oxidant outlet 148 via one or more oxidant discharge channels 146, preferably running substantially parallel to the stacking direction 130.

[0070] The oxidizing agent outlet 148 can in particular comprise one or more oxidizing agent passage openings in the gas distribution plate 140.

[0071] The oxidizer outlet 148 of the fuel cell stack 104 is connected to the oxidizer line 128, via which unreacted oxidizer in the fuel cell stack 104 can be supplied to the residual gas burner 106.

[0072] The (not shown) anode spaces of all fuel cell units 132 are also connected to a fuel gas outlet of the fuel cell stack 104 via one or more (not shown) fuel gas discharge channels.

[0073] The fuel gas outlet can include one or more fuel gas passage openings in the gas distribution plate 140.

[0074] The fuel gas outlet of the fuel cell stack 104 is connected to the fuel gas line 126, via which fuel gas not converted in the fuel cell stack 104 can be supplied to the residual gas burner 106.

[0075] The oxidant discharge channels 146 of the fuel cell stack 104 together form an oxidant outlet manifold 150.

[0076] The fuel gas outlet channels of the fuel cell stack 104 together form a fuel gas outlet manifold.

[0077] The oxidant supply channels 136 of the fuel cell stack 104 together form an oxidant inlet manifold 152.

[0078] The fuel gas supply channels 142 of the fuel cell stack 104 together form a fuel gas inlet manifold.

[0079] The fuel gas, which is incompletely converted in the fuel cell stack 104 and has a temperature of, for example, almost 850 °C, passes from the fuel gas outlet of the fuel cell stack 104 via the fuel gas line 126 to the fuel gas inlet of the residual gas burner 106.

[0080] The oxidizing agent, which is incompletely converted in the fuel cell stack 104, passes from the oxidizing agent outlet 148 of the fuel cell stack 104 via the oxidizing agent line 128 to the oxidizing agent inlet of the residual gas burner 106.

[0081] In order to be able to replace the fuel cell stack 104 separately from the reformer 102 and the residual gas burner 106 of the fuel cell device 100 and / or to subject it to a functional test before assembling the fuel cell device 100, the fuel cell stack 104 is not welded to the gas distribution plate 140, but is detachably connected to the gas distribution plate 140, for example by screwing.

[0082] To prevent the escape of fuel gas and / or oxidizing agent at the interface between the fuel cell stack 104 and the gas distribution plate 140, a seal 154 is arranged between the fuel cell stack 104 and the gas distribution plate 140.

[0083] The seal 154 preferably rests substantially flat against the fuel cell stack 104 and the gas distribution plate 140.

[0084] In this embodiment, the gas distribution plate 140 serves as the base body 156, which supports the fuel cell stack 104.

[0085] The seal 154 can, for example, comprise a nonwoven fabric, in particular a ceramic nonwoven fabric, as a sealing medium.

[0086] Such a nonwoven fabric can, for example, comprise ceramic fibers made of aluminum oxide and / or zirconium oxide.

[0087] In the area of ​​the oxidizer passage opening 138 and the fuel gas passage opening 144 in the gas distribution plate 140, corresponding passage openings are provided in the seal 154 to allow the passage of the oxidizer or the fuel gas through the seal 154.

[0088] To keep the requirements for the sealing effect of the seal 154 as low as possible, the base body 156, in this case the gas distribution plate 140, is connected to each oxidizing agent passage opening 138 by an oxidizing agent fluid line 158 (see the Fig. 2 and Fig. 4) provided, which is fluid-tightly connected to the base body 156, extends into the interior of the oxidizer inlet manifold 152 and opens into the interior of the oxidizer inlet manifold 152 at an outlet opening 160 spaced apart from the seal 154 in the stacking direction 130, so that the oxidizer entering the fuel cell stack 104 through the oxidizer fluid line 158 only enters the oxidizer inlet manifold 152 at a point away from the seal 154.

[0089] Preferably, the distance of the outlet opening 160 of the oxidizing agent fluid line 158 from the seal 154 along the stacking direction 130 is more than d, where d denotes the extent of a single fuel cell unit 132 of the fuel cell stack 104 along the stacking direction 130.

[0090] It is particularly advantageous if the distance of the outlet opening 160 from the seal 154 along the stacking direction 130 is more than D / 4, where D denotes the total height of all fuel cell units 132 of the fuel cell stack 104 along the stacking direction 130.

[0091] Preferably the distance of the outlet opening 160 from the seal 154 along the stacking direction 130 is more than D / 2, in particular more than 0.75 D.

[0092] The oxidizing agent fluid lines 158 are preferably made of a metallic material.

[0093] The oxidizing agent fluid lines 158 are preferably welded gas-tight to the base body 156.

[0094] When the fuel cell stack 104 docks to the base body 156, with the seal 154 interposed, the oxidant fluid lines 158 penetrate into the oxidant inlet manifold 152.

[0095] When the fuel cell device 100 is put into operation, the oxidizer flows through the oxidizer fluid lines 158 and enters the interior of the oxidizer inlet manifold 152 at the outlet openings 160 of the oxidizer fluid lines 158. From there, the oxidizer is distributed evenly to the cathode spaces 134 of the fuel cell units 132 in the successive stacking levels of the fuel cell stack 104.

[0096] The pressure of the oxidizing agent is at its maximum in the area of ​​the outlet openings 160 of the oxidizing agent fluid lines 158 (p max ) and decreases from level to level with increasing distance from the outlet openings 160 of the oxidizing agent fluid lines 158.

[0097] When the oxidizer mass flow reaches the end of the fuel cell stack 104 facing the seal 154, where the sealing medium is located, the pressure of the oxidizer is minimal (p min ) and the pressure difference between the interior of the oxidizer inlet manifold 152 and the environment of the fuel cell stack 104 is therefore significantly lower than in the area of ​​the outlet openings 160.

[0098] Since the leakage rate L corresponds to the product of this pressure difference and the volume flow rate of the oxidizing agent, the leakage rate depends linearly on the pressure difference across the seal 154. Because the oxidizing agent enters the interior of the oxidizing agent inlet manifold 152 via the oxidizing agent fluid lines 158 not directly downstream of the seal 154, but at a considerable distance from the seal 154, the pressure difference between the manifold area and the environment in the area of ​​the seal 154 is significantly reduced, resulting in a lower leakage rate.

[0099] This allows a lower leakage rate of the oxidizing agent from the fuel cell stack 104 to be achieved, regardless of the sealing medium used.

[0100] To also reduce the leakage rate of the fuel gas when passing from the base body 156 into the fuel cell stack 104, the base body 156 is equipped with fuel gas fluid lines 162 in the area of ​​the fuel gas passage openings 144 in the gas distribution plate 140 (see Fig. 3) provided which are fluid-tightly connected to the base body 156, extend into the interior of the fuel gas inlet manifold of the fuel cell stack 104 and open into the interior of the fuel gas inlet manifold of the fuel cell stack 104 at outlet openings spaced apart from the seal 154 in the stack direction 130.

[0101] The outlet openings of the fuel gas fluid lines 162 preferably have the distances from the seal 154 along the stacking direction 130 already defined above in connection with the oxidizing agent fluid lines 158.

[0102] In this way, even in the case of the fuel gas, the pressure difference between the interior of the fuel gas inlet manifold on the one hand and the environment of the fuel cell stack 104 on the other hand is significantly reduced across the seal 154, because the fuel gas is distributed from the outlet openings of the fuel gas fluid lines 162 over all fuel cell units 132 in the successive stacking levels of the fuel cell stack 104 along the stacking direction 130 and therefore the pressure of the fuel gas at the seal 154 is reduced compared to the pressure of the fuel gas at the outlet openings of the fuel gas fluid lines 162, as has already been described above in connection with the oxidizing agent.

[0103] Instead of being placed on a gas distribution plate 140, the fuel cell stack 104 can also be placed directly on the reformer 102 or the residual gas burner 106 of the fuel cell device 100, in which case the reformer 102 or the residual gas burner 106 serves as the base body 156, with which the oxidant fluid lines 158 or the fuel gas fluid lines 162 are fluid-tightly connected.

[0104] The oxidizing agent fluid lines 158 and the fuel gas fluid lines 162 are preferably formed in one piece from a tubular fluid line element 164.

[0105] The base body 156 and / or the fluid line elements 164 are preferably made of a metallic material.

Claims

[1] Fuel cell device comprising a fuel cell stack (104) in which fuel cell units (132) follow one another along a stacking direction (130), a base body (156) through which a fuel gas and / or an oxidizing agent can be supplied to the fuel cell stack (104), and a seal (154) for sealing between the fuel cell stack (104) and the base body (156), wherein the fuel cell device (100) comprises at least one fluid line (158, 162) which is fluid-tightly connected to the base body (156), extends into an interior of the fuel cell stack (104) and opens into the interior of the fuel cell stack (104) at an outlet opening (160) spaced apart from the seal (154) in the stack direction (130), and wherein the fuel cell stack (104) is detachably fixed to the base body (156), characterized by , that at least one fluid line (158, 162) is welded and / or soldered to the base body (156). [2] Fuel cell device according to claim 1, characterized by , that the outlet opening (160) of at least one fluid line (158, 162) has a distance from the seal (154) in the stacking direction (130) that is greater than a quarter of the extent of the fuel cell units (132) of the fuel cell stack (104) in the stacking direction (130). [3] Fuel cell device according to claim 2, characterized by , that the outlet opening (160) of at least one fluid line (158, 162) has a distance from the seal (154) in the stacking direction (130) that is greater than 75% of the extent of the fuel cell units (132) of the fuel cell stack (104) in the stacking direction (130). [4] Fuel cell device according to any one of claims 1 to 3, characterized by, that the outlet opening (160) of at least one fluid line (158, 162) is arranged in a fluid supply channel (136, 142) of the fuel cell stack (104), wherein the fluid supply channel (136, 142) extends substantially along the stacking direction (130) of the fuel cell stack (104). [5] Fuel cell device according to any one of claims 1 to 4, characterized by , that at least one fluid line (158, 162) comprises a tubular fluid line element (164). [6] Fuel cell device according to claim 5, characterized by , that at least one fluid line (158, 162) is formed in one piece from the tubular fluid line element (164). [7] Fuel cell device according to one of claims 5 or 6, characterized by , that a longitudinal axis of the fluid conduit element (164) is oriented substantially parallel to the stacking direction (130) of the fuel cell stack (104). [8] Fuel cell device according to any one of claims 1 to 7, characterized by , that the seal (154) comprises a nonwoven material. [9] Fuel cell device according to claim 8, characterized by , that the seal (154) comprises a ceramic nonwoven material. [10] Fuel cell device according to any one of claims 1 to 9, characterized by , that the fuel cell stack (104) is connected to the base body (156) by screwing. [11] Fuel cell device according to any one of claims 1 to 10, characterized by , that the base body (156) comprises a base plate (140). [12] Fuel cell device according to any one of claims 1 to 11, characterized by , that the base body (156) comprises a reformer (102) and / or a residual gas burner (106) of the fuel cell device (100). [13] Method for manufacturing a fuel cell device (100) comprising the following process steps: - Providing a fuel cell stack (104) comprising several successive fuel cell units (132) in a stacking direction (130) and a base body (156) through which a fuel gas and / or an oxidizing agent can be supplied to the fuel cell stack (104) during operation of the fuel cell device (100); - fluid-tight connection of at least one fluid line (158, 162) to the base body (156) by welding and / or soldering; - Arranging a seal (154) between the fuel cell stack (104) and the base body (156); and - Connecting the fuel cell stack (104) to the base body (156) such that the at least one fluid line (158, 162) extends into an interior of the fuel cell stack (104) and opens into the interior of the fuel cell stack (104) at an outlet opening (160) spaced apart from the seal (154) in the stack direction (130); wherein the fuel cell stack (104) is detachably fixed to the base body (156).

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