Fuel cell device and method for producing a fuel cell device

Abstract

The invention relates to a fuel cell device (10) and to a method for producing such a fuel cell device (10), comprising at least one component (14, 18, 36, 39), in particular a processor unit (14), preferably a heat exchanger (18, 36, 39), which is at least partially formed from steel. It is proposed that the steel of the at least one component (14, 18, 36, 39) is at least partially covered, preferably coated, with a metallic material (56) and / or a ceramic material (58).

Description

[0001] The present invention relates to a fuel cell device and a method for producing a fuel cell device, wherein at least one component of the fuel cell device, in particular a processor unit, preferably a heat exchanger, is at least partially formed of steel. Prior Art

[0002] Fuel cell devices are known from the prior art which include at least one processor unit, such as a heat exchanger, wherein the processor unit is made of steel. Summary of the Invention

[0003] The advantage of the present fuel cell device having the features of the main claim is that the steel of the at least one component is at least partially covered, preferably coated, with a metallic material and / or a ceramic material.

[0004] In the context of the present invention, "component" is to be understood in particular as a unit and / or a component of a fuel cell device.

[0005] In the context of the present invention, "unit" is to be understood in particular as a processor unit and / or a fuel cell unit. In particular, the fuel cell unit is a fuel cell stack and / or a fuel cell. Preferably, the fuel cell stack in turn includes a plurality of fuel cells.

[0006] In the context of the present invention, "processor unit" is to be understood in particular as a unit or a component of a fuel cell device which is not a fuel cell unit, or a fuel cell and / or a fuel cell stack. In particular, the processor unit is for the preferred chemical and / or thermal preparation and / or post-treatment of at least one medium to be converted and / or converted in the fuel cell unit, such as fuel gas, air and / or exhaust gas. The processor unit is preferably a reformer, a burner and / or a heat exchanger.

[0007] In the context of the present invention, "component" is to be understood in particular as a prefabricated and / or to-be-prefabricated part for constructing a fuel cell device. Such a part can be included by a unit of the fuel cell device and / or correspondingly be a part of the unit. Thus, in particular here it can be a part of a fuel cell unit, such as a (carrier) plate of a fuel cell stack. However, such a part can also not be included by a unit and / or, for example, be a part of the fuel cell device outside the unit. Thus, in particular here it can be a part connecting different units, such as a pipe for medium conduction.

[0008] Advantageous developments of the invention according to the main claim can be obtained by the features listed in the dependent claims.

[0009] Thus, it is advantageous that the metallic material comprises aluminum (Al), nickel (Ni), titanium (Ti), cobalt (Co), silicon (Si), copper (Cu) and / or manganese (Mn), and / or the ceramic material comprises oxides, nitrides and / or carbides, in particular oxides, nitrides and / or carbides of the metallic material, preferably aluminum oxide (Al 2 O 3 ), silicon nitride (Si 3 N 4 ) and / or titanium carbide (TiC).

[0010] In an advantageous embodiment, heat transfer is provided between the at least one component, in particular the processor unit, preferably the heat exchanger, wherein at least one of the at least two media-guiding spaces is covered, preferably coated, with a metallic material and / or a ceramic material.

[0011] It is advantageous to provide the at least one media-guiding space covered, preferably coated, with a metallic material and / or a ceramic material for guiding the media supplied to the fuel cell unit, in particular air.

[0012] It is also advantageous to provide the at least one media-guiding space covered, preferably coated, with a metallic material and / or a ceramic material for guiding the media discharged from the fuel cell unit, in particular the exhaust gas.

[0013] It is also advantageous that both of the at least two media-guiding spaces are covered, preferably coated, with a metallic material and / or a ceramic material.

[0014] The method for producing a fuel cell device according to the invention, in particular a fuel cell device according to the foregoing description, has the following advantages over the prior art: the steel of the at least one processor unit is at least partially covered, preferably coated, with a metallic material and / or a ceramic material.

[0015] In an advantageous embodiment, the metallic material is at least partially oxidized, nitrided and / or carbonized, in particular oxidized, nitrided and / or carbonized into a ceramic material, before assembling the at least one processor unit.

[0016] Preferably, by heat treatment, preferably in a furnace, the metallic material is at least partially oxidized, nitrided and / or carbonized.

[0017] In another advantageous embodiment, the metallic material is at least partially oxidized, nitrided and / or carbonized, in particular oxidized, nitrided and / or carbonized into a ceramic material, after assembling the at least one processor unit.

[0018] Preferably, during the operation of the fuel cell device, in particular during the initial operation, the metallic material is at least partially oxidized, nitrided and / or carbonized.

[0019] The present invention can simplify the production of fuel cell devices and improve the operating performance of fuel cell devices. In particular, fuel cell devices can be provided in a simpler and more economical manner, wherein power losses during the service life of the fuel cell device are reduced, while operating safety is improved and the environment is protected.

[0020] Accompanying drawings

[0021] Embodiments of the present invention are schematically shown in the accompanying drawings and are explained in more detail in the following description. Shown therein are

[0022] Figure 1 a schematic circuit diagram of an embodiment of a fuel cell device,

[0023] Figure 2 is Figure 1 a cross-sectional schematic view of a heat exchanger of an embodiment of the fuel cell device in

[0024] Embodiment description

[0025] Figure 1 A schematic circuit diagram of an embodiment of a fuel cell device 10 is shown. The fuel cell device 10 includes two fuel cell units 12. In the illustrated embodiment, the fuel cell unit 12 is designed as a fuel cell stack having a plurality of fuel cells (in this case, solid oxide fuel cells (Solid Oxide Fuel Cell, SOFC)). In addition, the fuel cell device 10 includes a plurality of processor units 14.

[0026] In the context of the present invention, a "processor unit" should be understood as a unit or component of the fuel cell device 10 in particular, which is not a fuel cell unit 12, or a fuel cell stack and / or a fuel cell. In particular, the processor unit 14 is for preferably chemically and / or thermally preparing and / or post-treating at least one medium to be converted and / or converted in the fuel cell unit, such as fuel gas B, RB, air L and / or exhaust gas A, KA, AA. The processor unit 14 is preferably a reformer 26, a combustor 28 and / or heat exchangers 18, 36, 39.

[0027] One of the processor units 14 is a heat exchanger 18 arranged in the air supply line 16, which is used to heat the oxygen-containing air L supplied to the fuel cell unit 12. In this case, the air L is supplied to each cathode chamber 20 of the fuel cell unit 12 during normal operation, for example, while the reformed fuel RB (in this case, hydrogen) is supplied to each anode chamber 22. In the fuel cell unit 12, the reformed fuel RB is electrochemically converted under the combined action of oxygen in the air L to generate current and heat.

[0028] The reformed fuel RB is generated by supplying fuel B (natural gas in this case) to the fuel cell device 10 through the fuel supply line 24, and the fuel B is reformed in a further processor unit 14 (a reformer 26 in this case).

[0029] In addition, the fuel cell unit 12 is connected to another processor unit 14 on the exhaust gas side, and is connected to a combustor 28 in this case. The exhaust gas of the fuel cell unit 12 (cathode exhaust gas KA in this case) is supplied to the combustor 28 through the cathode exhaust gas line 30, and a part of the anode exhaust gas AA is supplied to the combustor 28 through the anode exhaust gas line 32. The cathode exhaust gas KA contains unconsumed air L or unconsumed oxygen, and the anode exhaust gas AA optionally contains unreacted reformed fuel RB and / or optionally un-reformed fuel B. With the help of the combustor 28, the anode exhaust gas AA or the unreacted reformed fuel RB optionally contained therein and / or the un-reformed fuel B optionally contained therein burns in the case of being mixed with the oxygen of the cathode exhaust gas KA or the air L contained therein, so that additional heat can be generated.

[0030] The hot exhaust gas A generated during combustion in the combustor 28 is discharged from the combustor 28 through the exhaust gas line 34 via another processor unit 14 (via a heat exchanger 36 in this case). The heat exchanger 36 is in fluid connection with the reformer 26 here, so that the heat is transferred from the hot exhaust gas A to the fuel B supplied to the reformer 26. Accordingly, the heat of the hot exhaust gas A can be used to reform the fuel B supplied in the reformer 26.

[0031] Downstream of the heat exchanger 36, there is another processor unit 14 (a heat exchanger 18 in this case) in the exhaust gas line 34, so that the remaining heat of the hot exhaust gas A can be transferred to the air L supplied in the air supply line 16. Accordingly, the remaining heat of the hot exhaust gas can be used to preheat the air L supplied in the air supply line 16.

[0032] In addition, the fuel cell device 10 has a reflux line 38, through which a part of the anode exhaust gas AA can branch out from the anode exhaust gas line 32 and be supplied to the anode recirculation loop 40. Here, the branched anode exhaust gas AA passes through another processor unit 14 (another heat exchanger 39 in this case).

[0033] Through the anode recirculation loop 40, a branched portion of the anode exhaust gas AA can be returned or re-supplied to the respective anode chambers 22 of the fuel cell unit 12 and / or the reformer 26, so that the unreacted reforming fuel RB optionally contained in the branched anode exhaust gas AA can subsequently be converted in the fuel cell unit 12 and / or the un-reformed fuel B optionally contained in the branched anode exhaust gas AA can subsequently be reformed in the reformer 26. Thereby, the efficiency of the fuel cell device 10 can be further improved. In addition, fresh fuel B can be mixed into the branched anode exhaust gas AA recycled in the anode recirculation loop 40 through the fuel supply line 24. Then, with the aid of another heat exchanger 39, heat can be transferred from the branched anode exhaust gas AA from the return line 38 to the fuel mixture in the anode recirculation loop 40 generated due to the mixing of fresh fuel B for heat treatment.

[0034] Through the compressors 42 in the respective pipelines, the supply of air L in the air supply line 16, the supply of fuel B in the fuel supply line 24, and the recirculation rate of the anode exhaust gas AA in the anode recirculation loop 40 can be adjusted and / or coordinated with each other.

[0035] For the stable design of the components of the fuel cell device 10 (especially the processor unit 14 in the illustrated embodiment, such as the heat exchangers 18, 36, and / or 39), they are at least partially (completely in this case in the first step) made of steel. In the illustrated embodiment, the steel is especially high-temperature resistant stainless steel.

[0036] The present fuel cell device 10 is now characterized in that the steel of at least one component of the fuel cell device (the steel of at least one processor unit 14 in the illustrated embodiment) is at least partially covered with (coated in the illustrated case) a metal material 56 and / or a ceramic material 58.

[0037] In the illustrated embodiment, the metal material 56 can also be correspondingly understood as a metal layer 56. In the illustrated embodiment, the ceramic material 58 can also be correspondingly understood as a ceramic layer 58.

[0038] The metal material can include aluminum (Al), nickel (Ni), titanium (Ti), cobalt (Co), silicon (Si), copper (Cu), and / or manganese (Mn). In the illustrated case, the metal material includes aluminum (Al).

[0039] The ceramic material can include oxides, nitrides, and / or carbides, in this case oxides, nitrides, and / or carbides of the metal material, such as aluminum oxide (Al 2 O 3 ), silicon nitride (Si 3 N 4) and / or titanium carbide (TiC). In the shown case, the ceramic material comprises aluminum oxide (Al 2 O 3 ).

[0040] By means of the metallic material 56 and / or the ceramic material 58 (in this case by aluminum (Al) and aluminum oxide (Al 2 O 3 )) during the operation of the fuel cell device 10, the dissolution (so-called chromium evaporation) of chromium in the steel of at least one component of the fuel cell device 10 (in this case the processor unit 14) can be significantly reduced. Thereby, the power loss during the service life of the fuel cell device 10 can be reduced, and at the same time the operating safety of the fuel cell device 10 can be improved.

[0041] In the illustrated embodiment, the processor unit 14 (in this case the heat exchangers 18 and 36) comprises at least two medium guiding spaces 50, between which heat transfer is provided.

[0042] Accordingly, Figure 2 shows Figure 1 a cross-sectional schematic view of the heat exchanger 18 of the embodiment of the fuel cell device 10 in. In the illustrated embodiment, the heat exchanger 18 comprises two medium guiding spaces 50, specifically a first medium guiding space 52 and a second medium guiding space 54.

[0043] At least one of the at least two medium guiding spaces 50 (in the shown case the first medium guiding space 52) is covered, preferably coated, with the metallic material 56 and / or the ceramic material 58 (in the shown case aluminum (Al) and / or aluminum oxide (Al 2 O 3 ))). In the context of the present invention, this can also be understood as meaning that in particular the wall 60 of the medium guiding space 50 (preferably on the inside with respect to the medium guiding element) is covered, preferably coated, with the metallic material 56 and / or the ceramic material 58 (in the shown case aluminum (Al) and / or aluminum oxide (Al 2 O 3 ))). This makes it possible to specifically reduce the chromium evaporation in the medium guiding space 50. Therefore, the chromium content in the corresponding medium flow of the fuel cell device 10 can be specifically reduced.

[0044] In the shown case, one of the at least two medium guiding spaces 50 (in this example the first medium guiding space 52) is at least substantially completely covered or coated with the metallic material 56 and / or the ceramic material 58, or aluminum (Al) and / or aluminum oxide (Al 2 O 3 ).

[0045] In the illustrated embodiment, the at least one dielectric guiding space 50 (in the illustrated case, the first dielectric guiding space 52) covered, preferably coated, with a metallic material 56 and / or a ceramic material 58 is provided to guide the media B, RB, L (in this case, air L) to be supplied to the fuel cell unit 12. In this way, it is possible to specifically prevent chromium evaporation from occurring in the first dielectric guiding space 52 of the heat exchanger 18 during the operation of the fuel cell device 10, and to prevent the chromium dissolved therefrom from entering the fuel cell unit 12 through the media flow (in this case, the air flow) to be supplied to the fuel cell unit 12. Accordingly, chromium enrichment in the fuel cell unit 12 can be at least substantially prevented, thereby reducing the power loss in the fuel cell unit 12 caused by chromium enrichment.

[0046] In an alternative embodiment (not shown), the at least one dielectric guiding space 50 covered, preferably coated, with a metallic material 56 and / or a ceramic material 58, in particular aluminum (Al) and / or aluminum oxide (Al 2 O 3 2) can also be provided to guide the media A, AA, KA discharged from the fuel cell unit 12, in particular the exhaust gas A. In this context, the second dielectric guiding space 54 of the heat exchanger 18 can be covered, preferably coated, with a metallic material 56 and / or a ceramic material 58, in particular aluminum (Al) and / or aluminum oxide (Al 2 O 3 2). However, in this context, the dielectric guiding space of the heat exchanger 36 guiding the exhaust gas A can also be covered, preferably coated, with a metallic material 56 and / or a ceramic material 58, in particular aluminum (Al) and / or aluminum oxide (Al 2 O 3 2). In both cases, it is possible to specifically prevent chromium evaporation from occurring in the corresponding dielectric guiding spaces of the heat exchanger 18 or 36 during the operation of the fuel cell device 10, and to prevent the chromium that may be dissolved therefrom from escaping from the fuel cell device 10 through the media flow (in this case, the exhaust gas flow) discharged from the fuel cell unit 12, in particular into the atmosphere. Accordingly, the risk of chromium enrichment in the atmosphere can be reduced, thereby improving safety and also protecting the environment.

[0047] In another alternative embodiment (not shown), both of the at least two dielectric guiding spaces 50 of the heat exchanger 18 can also be covered, preferably coated, with a metallic material 56 and / or a ceramic material 58, in particular aluminum (Al) and / or aluminum oxide (Al 2 O 3 2). This makes it possible to both reduce the power loss in the fuel cell unit 12 caused by chromium enrichment and reduce the risk of chromium enrichment in the atmosphere, or improve safety and also protect the environment.

[0048] For the illustrated embodiment, before assembling the fuel cell device 10 or before assembling into the fuel cell device 10, at least one component of the fuel cell device (in the illustrated case at least one processor unit 14, in this example a heat exchanger 18, specifically a first medium guiding space 52) is coated with a metallic material 56 (in the illustrated embodiment aluminum (Al)).

[0049] Within the scope of the present invention, now, before assembling the at least one component (in the illustrated case the at least one processor unit 14, in this example a heat exchanger 18), the metallic material 56 is at least partially oxidized, nitrided and / or carbonized. In the illustrated case, specifically, aluminum (Al) will be oxidized to aluminum oxide (Al 2 O 3 ). Thereby, an inexpensive method for forming a ceramic material 58 on the steel of the processor unit 14 will be achieved.

[0050] It is conceivable here that the metallic material 56 is at least partially oxidized, nitrided and / or carbonized by heat treatment, for example in a furnace. Thus, in the illustrated case, a particularly inexpensive method for forming a ceramic material 58 on the steel of the processor unit 14 will be achieved.

[0051] However, alternatively, for the illustrated embodiment, after assembling the at least one component or processor unit 14 (in this example a heat exchanger 18), the metallic material 56 or aluminum (Al) is at least partially oxidized, nitrided and / or carbonized, oxidized in the illustrated case. This makes it possible to omit, for example, the oxidation, nitriding and / or carbonization steps in a furnace, thereby simplifying the production of the fuel cell device 10 again.

[0052] For the illustrated embodiment, during the operation or initial operation of the fuel cell device 10, the metallic material 56 is at least partially (in this case substantially) oxidized, nitrided and / or carbonized. In this case, specifically, during the operation or initial operation of the fuel cell device 10, aluminum (Al) is oxidized to aluminum oxide (Al 2 O 3 ). This is also a heat treatment, where this precisely occurs during the operation or initial operation of the fuel cell device 10. Thereby, the production of the fuel cell device 10 can be particularly simplified.

[0053] Therefore, the fuel cell device 10 of the illustrated embodiment includes a component, in the illustrated case a processor unit 14, specifically a heat exchanger 18, which is at least partially covered with or coated with a metallic material 56 or aluminum (Al) and a ceramic material 58 or aluminum oxide (Al 2 O 3), but at different times. Thus, before or during the assembly of the fuel cell device 10 or when assembled into the fuel cell device 10, the component or the processor unit 14 (in this example, the heat exchanger 18) is only coated with the metal material 56 or aluminum (Al) in the illustrated embodiment. After the fuel cell device 10 is operated or initially operated, or after the metal material 56 is oxidized, nitrided, and / or carbonized, the component or the processor unit 14 (in this example, the heat exchanger 18) is only coated with the ceramic material 58 or aluminum oxide (Al 2 O 3 ). Accordingly, the operation or initial operation of the fuel cell device 10 can still be understood as part of the method of manufacturing the fuel cell device 10.

[0054] In both cases of heat treatment, before assembly, for example, in a furnace, or during the operation of the fuel cell device 10, this is advantageously carried out in the temperature range of 350 °C to 1100 °C, particularly 500 °C to 950 °C, preferably at a temperature of 850 °C.

[0055] When the heat treatment is carried out in the temperature range of 500 °C to 950 °C, the metal material 56 (in this example, at least 70%) is advantageously oxidized, nitrided, and / or carbonized into the ceramic material 58, particularly aluminum (Al) is oxidized into aluminum oxide (Al 2 O 3 ).

[0056] When the heat treatment is carried out at a temperature of 850 °C, almost the entire metal material 56 (in this case, at least 90% of the metal material 56) is particularly advantageously oxidized, nitrided, and / or carbonized into the ceramic material 58, particularly aluminum (Al) is oxidized into aluminum oxide (Al 2 O 3 ).

[0057] In the illustrated embodiment, the steel covered or coated with the metal material 56 or the metal layer 56 has a thickness of 100 μm, while the metal material 56 or the metal layer 56 has a thickness of 1 - 2 μm. During the oxidation, nitridation, and / or carbonization of the metal material 56 or the metal layer 56, its thickness decreases, so that the ceramic material 58 or the ceramic layer 58 formed here has a thickness of 0.5 - 2 μm. Thus, a thick enough ceramic layer 58 is formed, which particularly advantageously avoids the chromium evaporation explained previously.

Claims

1. A fuel cell device (10) comprising at least one component (14, 18, 36, 39), in particular a processor unit (14), preferably heat exchangers (18, 36, 39), which is at least partially formed of steel, characterized in that, the steel of the at least one component (14, 18, 36, 39) is at least partially covered, preferably coated, with a metallic material (56) and / or a ceramic material (58).

2. The fuel cell device (10) according to claim 1, characterized in that, The metallic material (56) comprises aluminum (Al), nickel (Ni), titanium (Ti), cobalt (Co), silicon (Si), copper (Cu) and / or manganese (Mn), and / or the ceramic material (58) comprises oxides, nitrides and / or carbides, in particular oxides, nitrides and / or carbides of the said metallic material (56), preferably alumina (Al 2 O 3 ), silicon nitride (Si 3 N 4 ) and / or titanium carbide (TiC).

3. The fuel cell device (10) according to any one of claims 1 or 2, characterized in that, the at least one component (14, 18, 36, 39), in particular the processor unit (14), preferably the heat exchangers (18, 36, 39) comprises at least two medium guiding spaces (50, 52, 54) in which heat transfer is provided between the medium guiding spaces, wherein at least one of the at least two medium guiding spaces (50, 52, 54) is covered, preferably coated, with a metallic material (56) and / or a ceramic material (58).

4. The fuel cell device (10) according to claim 3, characterized in that, the at least one medium guiding space (52) covered, preferably coated, with a metallic material (56) and / or a ceramic material (58) is provided to guide the medium (B, RB, L), in particular air (L), supplied to the fuel cell unit (12).

5. The fuel cell device (10) according to claim 3 or 4, characterized in that, the at least one medium guiding space covered, preferably coated, with a metallic material (56) and / or a ceramic material (58) is provided to guide the medium (A, AA, KA), in particular the exhaust gas (A), discharged from the fuel cell unit.

6. The fuel cell device (10) according to claim 3, characterized in that, both of the at least two medium guiding spaces (50, 52, 54) are covered, preferably coated, with a metallic material (56) and / or a ceramic material (58).

7. A method of manufacturing a fuel cell device (10), in particular a fuel cell device (10) according to any one of the preceding claims, wherein at least one component (14, 18, 36, 39) of the fuel cell device (10), in particular a processor unit (14), preferably heat exchangers (18, 36, 39) is at least partially formed of steel, characterized in that, the steel of the at least one component (14, 18, 36, 39) is at least partially covered, preferably coated, with a metallic material (56) and / or a ceramic material (58).

8. The method according to claim 7, characterized in that, before assembling the at least one component (14, 18, 36, 39), the metallic material (56) is at least partially oxidized, nitrided and / or carbonized, in particular oxidized, nitrided and / or carbonized into a ceramic material (58).

9. The method according to claim 8, characterized in that, the metallic material (56) is at least partially oxidized, nitrided and / or carbonized by heat treatment, preferably in a furnace.

10. The method according to claim 7, characterized in that, After assembling the at least one component (14, 18, 36, 39), the metallic material (56) is at least partially oxidized, nitrided and / or carbonized, in particular oxidized, nitrided and / or carbonized to a ceramic material (58).

11. The method according to claim 10, characterized in that during operation of the fuel cell device (10), in particular during initial operation, the metallic material (56) is at least partially oxidized, nitrided and / or carbonized.

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