Fuel cell module
The fuel cell module uses overlapping plate materials with recessed flow path grooves to connect gas pipes without bending, addressing layout and machinability issues, reducing parts, and enhancing sealing and compactness.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- AISIN CORP
- Filing Date
- 2022-09-29
- Publication Date
- 2026-06-30
AI Technical Summary
Existing fuel cell modules face layout and machinability issues due to the use of piping materials with low ductility, requiring large bending radii, and forming flow paths with flow path plates increases the number of parts.
A fuel cell module configuration using two plate materials with recessed flow path grooves and connection ports, allowing gas pipes to connect without bending, reducing the number of parts and ensuring strength and sealing performance.
The configuration minimizes parts, avoids layout and processing issues, reduces pressure loss, and enhances sealing performance while maintaining a compact design.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a fuel cell module.
Background Art
[0002] Conventionally, a fuel cell module has been proposed that includes a fuel cell that generates electricity based on an anode gas (fuel gas) and a cathode gas (air), a reformer that steam-reforms a raw fuel gas to generate the anode gas, a combustion unit that burns the anode off-gas discharged from the fuel cell to heat the reformer, and an evaporator that performs heat exchange between the combustion exhaust gas discharged from the combustion unit and reformed water to generate steam. For example, in the fuel cell module of Patent Document 1, a mixed gas supply pipe for supplying a mixed gas of the steam generated by the evaporator and the raw fuel gas to the reformer is provided. One end of the mixed gas supply pipe is connected to the reformer, extends substantially horizontally therefrom, then bends at a right angle and extends in the vertical direction, and the other end is connected to the evaporator.
[0003] Further, Patent Document 2 describes a heat exchange device that heats or cools a fluid such as a gas or a liquid, in which a flow path is formed by joining flow path plates in which flow path grooves are formed by press working. The flow path plates are provided with pipe-shaped inlets and outlets that communicate with the flow path grooves.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0005] As shown in Patent Document 1, some fuel cell modules use piping to form the flow paths for various gases. However, piping materials usable in high-temperature environments have relatively low ductility, requiring a large bending radius for the piping. This can lead to layout and workability problems in sections requiring bends such as right-angle bends. Alternatively, as shown in Patent Document 2, it is possible to form flow paths using flow path plates, but this increases the number of parts, as separate components are needed to connect the piping to the pipe-shaped inlet and outlet.
[0006] The primary purpose of this disclosure is to provide a configuration for the bent portion of a gas flow path that minimizes the number of parts while avoiding layout and machinability issues. [Means for solving the problem]
[0007] This disclosure employs the following means to achieve the primary objectives described above.
[0008] The fuel cell module disclosed herein is A fuel cell that generates electricity based on anode gas and cathode gas, A combustion section for burning off-gas from the fuel cell, A flow path forming section that forms a part of the flow path for at least one of the anode gas, cathode gas, and off-gas, Equipped with, The flow path forming section comprises two plate materials, each having a connection port through which a gas pipe forming the flow path of one of the gases can be connected, and a flow path groove recessed in a concave shape relative to the mating surface. The two plate materials are assembled by overlapping their mating surfaces such that the flow path groove communicates with the connection port of the mating plate material and a portion of the flow path grooves overlap each other. This is the gist of it.
[0009] In the fuel cell module of this disclosure, the flow path forming section comprises two plate materials, each having a connection port through which a gas pipe can be connected, and a flow path groove recessed in a concave shape relative to the mating surface. The two plate materials are stacked on top of each other such that the flow path groove communicates with the connection port of the other plate material, and a portion of the flow path grooves overlap each other. This allows the gas pipe connected to the connection port of one plate material and the gas pipe connected to the connection port of the other plate material to be connected in a way that allows gas to flow through the flow path forming section. Therefore, since it is only necessary to secure space for the overlapping portion of the flow path grooves, there is no need to bend the pipe or consider the space required for the bending radius of the pipe. In addition, by stacking the two plate materials, the strength of the flange portion of the connection port can be ensured while keeping the number of parts down. Thus, the bent portion of the gas flow path can be configured with a reduced number of parts while avoiding layout and processability problems.
[0010] In the fuel cell module of this disclosure, the flow path forming portion may be configured such that the flow path grooves are formed such that the flat portions of the groove bottoms face each other and overlap as part of the flow path grooves. This prevents the flow path from narrowing in the connecting portions of the flow path grooves, thereby reducing pressure loss when gas flows.
[0011] In the fuel cell module of this disclosure, the flow path forming portion may be configured such that each of the two plate materials has a plurality of fastening holes formed around the connection port and around the flow path groove of the mating plate material communicating with the connection port, which are fastened together by fastening members, and an annular sealing member having through holes corresponding to the connection port is positioned between the plate material and the flange portion of the gas piping. In this way, the plate thickness can be increased by the two plate materials to ensure flange rigidity, thereby improving sealing performance.
[0012] In the fuel cell module of this disclosure, the flow path forming section may be such that one of the two plate materials has a flow path groove formed therein, one end of which communicates with the connection port of the mating plate material, and at least two connection ports are formed therein as the connection port, and the other of the two plate materials has a branch flow path groove formed therein as the flow path groove, both ends of which communicate with the two connection ports of the mating plate material, and in the middle of the flow path it communicates with the other end of the flow path groove of the mating plate material, branching the gas that has flowed through the flow path groove of the mating plate material and discharging it from each of the two connection ports. In this way, not only is a bent portion of the flow path formed, but the flow path can also be branched as needed, thus saving space.
[0013] In the fuel cell module of the present disclosure, the combustion section is located above the fuel cell, and the flow path forming section has two plate members positioned vertically between the fuel cell and the combustion section, the lower plate member having a first flow path groove and a second flow path groove formed therein as flow path grooves, and having a first connection port to which a discharge pipe for anode off gas discharged from the fuel cell is connected and a second connection port to which a discharge pipe for cathode off gas discharged from the fuel cell is connected as connection ports, the upper plate member is The flow channel groove may be configured to include a third flow channel groove that communicates with the first connection port and partially overlaps with the first flow channel groove, and a fourth flow channel groove that communicates with the second connection port and partially overlaps with the second flow channel groove. The connection port may be configured to include a third connection port that is connected to the first flow channel groove and to which a supply pipe for supplying anode-off gas to the combustion section is connected, and a fourth connection port that is connected to the second flow channel groove and to which a supply pipe for supplying cathode-off gas to the combustion section is connected. In this way, since the flow channels for anode-off gas and cathode-off gas are formed in a single flow channel forming section, the number of parts can be reduced and space can be saved. Furthermore, by arranging the flow channel forming section between the fuel cell and the combustion section, the fuel cell module can be made more compact. [Brief explanation of the drawing]
[0014] [Figure 1] It is an external perspective view of the fuel cell module 10. [Figure 2] It is a side view of the fuel cell module 10. [Figure 3] It is a schematic configuration diagram of the fuel cell module 10. [Figure 4] It is an external perspective view of the flow path forming part 50. [Figure 5] It is a schematic configuration diagram of the lower plate 51. [Figure 6] It is a schematic configuration diagram of the upper plate 61. [Figure 7] It is a partially enlarged view of the flow path forming part 50. [Figure 8] It is a partial cross-sectional view of the flow path forming part 50. [Figure 9] It is an explanatory diagram showing the state in which gas flows through the flow path forming part 50.
Embodiments for Carrying out the Invention
[0015] Next, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is an external perspective view of the fuel cell module 10. FIG. 2 is a side view of the fuel cell module 10. FIG. 3 is a schematic configuration diagram of the fuel cell module 10. As shown in the drawings, the fuel cell module 10 includes a fuel cell stack 11, an evaporation unit 12, a reforming unit 20, a condenser 40, and a flow path forming part 50. The fuel cell stack 11 generates electricity through an electrochemical reaction between hydrogen in the anode gas and oxygen in the cathode gas. The evaporation unit 12 evaporates the reformed water to generate water vapor. The reforming unit 20 reforms the raw fuel gas (e.g., natural gas or LP gas) by steam reforming to generate the anode gas. The fuel cell stack 11, the evaporation unit 12, the reforming unit 20, and the flow path forming part 50 are housed in a box-shaped module case 15 having heat insulation properties. The condenser 40 is installed outside the module case 15. The flow path forming part 50 is disposed between the reforming unit 20 and the fuel cell stack 11.
[0016] The fuel cell module 10 constitutes a fuel cell system together with a raw fuel gas supply device, a reformed water supply device, an air supply device, and a hot water storage tank, not shown in the figure. The raw fuel gas supply device supplies raw fuel gas to the evaporation unit 12 through the raw fuel gas supply pipe 31a. The reformed water supply device supplies reformed water necessary for reforming (steam reforming) the raw fuel gas into anode gas to the evaporation unit 12 through the reformed water supply pipe 31b. The air supply device supplies air as cathode gas to the fuel cell stack 11 through the air supply pipe 34. Further, the hot water storage tank recovers the heat generated in the fuel cell module 10 and stores hot water.
[0017] The fuel cell stack 11 includes a plurality of solid oxide type single cells each having an electrolyte such as zirconium oxide and an anode and a cathode sandwiching the electrolyte. An anode gas flow path is connected to the anode of each single cell. Also, a cathode gas flow path is connected to the cathode of each single cell.
[0018] A supply pipe 31 connected to the raw fuel gas supply pipe 31a and the reformed water supply pipe 31b is connected to the evaporation unit 12. The raw fuel gas supplied from the raw fuel gas supply device to the raw fuel gas supply pipe 31a and the reformed water supplied from the reformed water supply device to the reformed water supply pipe 31b are introduced into the evaporation unit 12 from the supply pipe 31. The evaporation unit 12 is filled with a plurality of spherical heat storage members having a high thermal conductivity inside, and when the heat storage members are heated and reformed water flows in, the reformed water is evaporated to generate water vapor. The heat storage members are made of materials such as alumina and stainless steel (for example, ferritic stainless steel). Also, when the raw fuel gas is introduced, the evaporation unit 12 preheats the raw fuel gas. The mixed gas of the water vapor generated in the evaporation unit 12 and the preheated raw fuel gas is supplied to the reforming unit 20 (reforming section 22) through the mixed gas supply pipe 32.
[0019] As shown in Figures 1 and 2, the reforming unit 20 is formed in a substantially cylindrical shape and, as shown in Figure 3, integrally houses the reforming section 22, the combustion section 23, and the air heat exchange section 24. The combustion section 23, the reforming section 22, and the air heat exchange section 24 (combustion exhaust gas flow section 24a, air flow section 24b) are formed in a bottomed cylindrical shape and arranged concentrically. An igniter 25 is provided in the center of the upper wall of the reforming unit 20, extending into the combustion section 23 for ignition within the combustion section 23. The evaporation section 12 is formed separately from the reforming unit 20. In Figure 3, the evaporation section 12 is positioned to the side of the reforming unit 20, but it may also be positioned above the reforming unit 20.
[0020] The combustion section 23 is supplied with anode-off gas and cathode-off gas containing oxygen as fuel from below. Although not shown in the figures, the combustion section 23 has a fuel nozzle for injecting anode-off gas and a supply cylinder formed in a cylindrical shape surrounding the fuel nozzle for supplying cathode-off gas.
[0021] The reforming section 22 is formed in a bottomed cylindrical shape, and a reforming catalyst (not shown), such as a Ru-based or Ni-based one, is arranged in the internal space, with the outer wall of the combustion section 23 as its inner wall. The reforming section 22 also has a supply port on its upper wall to which a mixed gas supply pipe 32 is connected, and the mixed gas (raw fuel gas and water vapor) that has passed through the mixed gas supply pipe 32 is supplied to the internal space from the supply port. In the presence of heat from the combustion section 23, the reforming section 22 generates hydrogen gas and carbon monoxide through a reaction of the mixed gas by the reforming catalyst (water vapor reforming reaction). Furthermore, the reforming section 22 generates hydrogen gas and carbon dioxide through a reaction between the carbon monoxide generated in the water vapor and water vapor (carbon monoxide shift reaction). As a result, the reforming section 22 generates an anode gas containing hydrogen, carbon monoxide, carbon dioxide, water vapor, and unreformed raw fuel gas. The reforming section 22 has an outlet on its bottom wall to which an anode gas pipe 33 is connected. The generated anode gas flows from the outlet through the anode gas pipe 33 into the anode gas flow path of each single cell of the fuel cell stack 11 and is supplied to the anode.
[0022] The air heat exchange section 24 is formed in a bottomed cylindrical shape and has a combustion exhaust gas flow section 24a through which combustion exhaust gas generated in the combustion section 23 flows, and an air flow section 24b which is also formed in a bottomed cylindrical shape and through which air supplied from the air supply pipe 34 flows. The combustion exhaust gas flow section 24a forms an internal space with the outer wall of the reforming section 22 as its inner wall, and an outlet to which the combustion exhaust gas piping 39 is connected is formed in the upper wall. The combustion exhaust gas that flows through the combustion exhaust gas flow section 24a and is discharged from the outlet is supplied to the evaporation section 12 through the combustion exhaust gas piping 39, where it undergoes heat exchange with reformed water and raw fuel gas before being supplied to the condenser 40.
[0023] The air circulation section 24b has a supply port formed on its upper wall to which the air supply pipe 34 of the air supply device is connected, and an outlet formed on its side wall to which the cathode gas piping 35 is connected, forming an internal space with the outer wall of the combustion exhaust gas circulation section 24a as its inner wall. The air flowing through the air circulation section 24b is heated by heat exchange with the combustion exhaust gas flowing through the combustion exhaust gas circulation section 24a. The air that flows through the air heat exchange section 24 and is discharged from the outlet flows as cathode gas through the cathode gas piping 35 into the cathode gas flow path of each single cell of the fuel cell stack 11 and is supplied to the cathode.
[0024] In the cathode of each single cell, oxide ions (O 2- Oxide ions are generated, and these oxide ions permeate the electrolyte and react with hydrogen and carbon monoxide at the anode to obtain electrical energy. The output terminal of the fuel cell stack 11 is connected to the input terminal of a power conditioner, and the power generated by the fuel cell stack 11 is converted into AC power by the power conditioner and supplied to the electrical load.
[0025] In each single cell, anode gas (hereinafter referred to as "anode-off gas") that was not used in the electrochemical reaction (power generation) is supplied to the combustion section 23 through the anode-off gas flow path 36. Similarly, cathode gas (hereinafter referred to as "cathode-off gas") that was not used in the electrochemical reaction (power generation) in each single cell is supplied to the combustion section 23 through the cathode-off gas flow path 37. The anode-off gas flow path 36 and the cathode-off gas flow path 37 are partially formed by the flow path forming section 50, and details will be described later. The anode-off gas is a combustible gas containing fuel components such as hydrogen and carbon monoxide, and is mixed with cathode-off gas containing oxygen in the combustion section 23. The igniter 25 then ignites the mixed gas of anode-off gas and cathode-off gas, causing the mixed gas to burn. The combustion of the mixed gas generates heat necessary for the operation of the fuel cell stack 11, preheating of the raw fuel gas and generation of steam in the evaporation section 12, and the steam reforming reaction in the reforming section 22.
[0026] The combustion exhaust gas generated by the combustion of the mixed gas in the combustion section 23 passes through the air heat exchange section 24 (combustion exhaust gas flow section 24a) of the reforming unit 20, then through the combustion exhaust gas piping 39 and through the evaporation section 12. The combustion exhaust gas is supplied to the condenser 40 after supplying the heat necessary for steam reforming, the heat necessary for raising the temperature of the cathode gas (air), and the heat necessary for generating steam. The combustion exhaust gas supplied to the condenser 40 is cooled by heat exchange with hot water from the hot water storage tank, and at least a portion of the steam contained in the combustion exhaust gas is removed before it is discharged into the atmosphere. The water obtained by condensing the steam contained in the combustion exhaust gas is stored in the reformed water tank and used as reformed water.
[0027] The configuration of the flow path forming section 50 will be described below. Figure 4 is an external perspective view of the flow path forming section 50. Figure 5 is a schematic configuration diagram of the lower plate 51. Figure 6 is a schematic configuration diagram of the upper plate 61. Figure 7 is a partially enlarged view of the flow path forming section 50. Figure 8 is a partially cross-sectional view of the flow path forming section 50. The flow path forming section 50 forms a curved portion, for example, a crank-shaped portion, as a bending portion of the anode-off gas flow path 36 and the cathode-off gas flow path 37. Figure 8 shows an example of a partially cross-sectional view of the cathode-off gas flow path 37 formed by the flow path forming section 50. This flow path forming section 50 is constructed by overlapping two plate materials, for example, metal plates such as ferritic stainless steel that have been press-formed, and airtightness is ensured by bonding the two plate materials together by welding (for example, laser welding). The flow path forming section 50 is arranged between the fuel cell stack 11 and the combustion section 23, with the two plate materials positioned vertically, for example, so that the mating surfaces are horizontal.
[0028] As shown in Figures 4 and 5, the lower plate 51 has a first flow channel groove 52, a second flow channel groove 53, a first connection port 54, a second connection port 55, and a plurality of fastening holes 58. The first flow channel groove 52 and the second flow channel groove 53 are recessed flow channel grooves relative to the mating surface of the lower plate 51 (the upper surface in Figure 5). The first flow channel groove 52 is formed to bend in a roughly crank shape when viewed from above, from one end 52a to the other end 52b. The second flow channel groove 53 is formed in a straight line from one end 53a to the other end 53b.
[0029] The first connection port 54 and the second connection port 55 are circular through-holes that penetrate the lower plate 51. The anode off-gas discharge pipe 36a (discharge piping), from which anode off-gas is discharged from the fuel cell stack 11, is flange-connected to the first connection port 54. Note that the flanges of each pipe are not shown in Figure 4. The first connection port 54 is also called the first communication port because it communicates with the anode off-gas discharge pipe 36a via a flange connection. Similarly, the second connection port 55 and the third connection port 64 and fourth connection port 65, which will be described later, are also called the second communication port, third communication port, and fourth communication port. The cathode off-gas discharge pipe 37a (discharge piping), from which cathode off-gas is discharged from the fuel cell stack 11, is flange-connected to the second connection port 55. The fastening holes 58 are circular through-holes that penetrate the lower plate 51 and are formed around the first connection port 54, the second connection port 55, one end 52a of the first flow channel groove 52, and one end 53a of the second flow channel groove 53.
[0030] As shown in Figures 4 and 6, the upper plate 61 has a third flow channel groove 62, a fourth flow channel groove 63, a third connection port 64, a fourth connection port 65, a fifth connection port 66, a mounting port 67, and a number of fastening holes 68. The third flow channel groove 62 and the fourth flow channel groove 63 are flow channel grooves that are recessed in a concave shape relative to the mating surface of the upper plate 61 (the lower surface in Figure 6). The third flow channel groove 62 is formed in a straight line from one end 62a to the other end 62b, and communicates with the first connection port 54 of the lower plate 51, while partially overlapping with the middle of the first flow channel groove 52. The fourth flow channel groove 63 is formed in a straight line from one end 63a to the other end 63b, and communicates with the second connection port 55 of the lower plate 51, while partially overlapping with the other end 53b of the second flow channel groove 53.
[0031] The third connection port 64 and the fourth connection port 65 are circular through-holes that penetrate the upper plate 61. The anode-off gas supply pipe 36b (supply piping) that supplies anode-off gas to the combustion section 23 is flange-connected to the third connection port 64. The third connection port 64 also communicates with one end 52a of the first flow channel groove 52 of the lower plate 51. The cathode-off gas supply pipe 37b (supply piping) that supplies cathode-off gas to the combustion section 23 is flange-connected to the fourth connection port 65. The fourth connection port 65 also communicates with one end 53a of the second flow channel groove 53 of the lower plate 51. The recirculation piping 38 for recirculating a portion of the anode-off gas to the raw fuel gas supply pipe 31a is connected to the fifth connection port 66. The fifth connection port 66 also communicates with the other end 53b of the second flow channel groove 53 of the lower plate 51. The mounting opening 67 is formed by penetrating the bottom surface of the groove at one end of the fourth flow channel groove 63, and a protective tube 18 for a temperature sensor for measuring the temperature of the cathode-off gas is attached thereto.
[0032] The fastening holes 68 are circular through-holes that penetrate the upper plate 61 and are formed around the third connection port 64, the fourth connection port 65, one end 62a of the third flow channel groove 62, and one end 63a of the fourth flow channel groove 63. Each fastening hole 68 is formed in a position that communicates with each other when the lower plate 51 and the upper plate 61 are superimposed. Note that each fastening hole 58, 68 can be formed by passing through the lower plate 51 and the upper plate 61 when they are superimposed.
[0033] Furthermore, an annular sealing member, a gasket 70, is positioned in the flow path forming section 50 at a location corresponding to each connection port (54, 55, 64, 65). The gasket 70 shown in Figure 7 has a central through-hole positioned at a location corresponding to the second connection port 55 of the lower plate 51, and is sandwiched between the flange portion 37f of the cathode-off gas discharge pipe 37a (see Figure 8) and the flange-like portion (peripheral portion) around the second connection port 55. In Figure 8, the flange portion 37f of the cathode-off gas discharge pipe 37a and the flow path forming section 50 (lower plate 51) are shown separated, but the gasket 70 is sandwiched by fastening using fastening members such as bolts (not shown) inserted into fastening holes 58, 68 and fastening hole 37h of the flange portion 37f. Furthermore, as shown in Figure 8, the gasket 70 positioned with a through hole corresponding to the fourth connection port 65 of the upper plate 61 is sandwiched between the flange portion 37f of the cathode-off gas supply pipe 37b and the flange-like portion (peripheral portion) around the fourth connection port 65. Gaskets 70 are also positioned at the locations corresponding to the other first connection ports 54 and third connection ports 64, and are similarly sandwiched. In this way, each gasket 70 positioned at the location corresponding to each connection port (54, 55, 64, 65) is sandwiched between the flange-like peripheral portions of the lower plate 51 and the upper plate 61 and the flange portions of each pipe. Therefore, the flow path forming section 50 can have twice the plate thickness by overlapping two plate materials to ensure flange rigidity, thereby improving sealing performance.
[0034] Here, Figure 9 is an explanatory diagram showing how gas flows in the flow path forming section 50. In Figure 9 and Figure 8 mentioned above, the gas flow is indicated by dotted arrows. The cathode-off gas flows from the cathode-off gas discharge pipe 37a into the fourth flow path groove 63, flows through the fourth flow path groove 63 and the second flow path groove 53, is discharged to the cathode-off gas supply pipe 37b, and flows through the cathode-off gas supply pipe 37b to be supplied to the combustion section 23. The second flow path groove 53 and the fourth flow path groove 63 are connected in such a way that they partially overlap, and as shown in Figure 8, the flat portions of the groove bottoms are formed to overlap each other (area A in Figure 8). The second flow path groove 53 and the fourth flow path groove 63 may extend in the same direction, and more than half of their length in the longitudinal direction (extension direction) may overlap each other. Thus, the second flow channel groove 53 and the fourth flow channel groove 63 of the flow channel forming section 50 connect the cathode-off gas discharge pipe 37a and the cathode-off gas supply pipe 37b, which extend parallel to each other in the vertical direction, in the horizontal direction. Since the bent portion of the flow channel is formed in a space equal to the height (thickness) of the second flow channel groove 53 and the fourth flow channel groove 63, it is possible to save space compared to forming it by bending the pipe. In addition, since the flat portions of the groove bottoms face each other and overlap, it is possible to prevent the flow channel in the connecting portion from narrowing compared to a design where the flat portions do not face each other, thereby reducing pressure loss when cathode-off gas flows through it.
[0035] Furthermore, as shown in Figure 9, the anode-off gas flows from the anode-off gas discharge pipe 36a into the third flow channel groove 62, and then flows from the third flow channel groove 62 into the first flow channel groove 52. As described above, the first flow channel groove 52 of the lower plate 51 is formed to bend in a roughly crank shape, and the third flow channel groove 62 of the upper plate 61 is formed to overlap the middle (bent portion) of the first flow channel groove 52. For this reason, the anode-off gas that flows into the first flow channel groove 52 branches to one end 52a and the other end 52b. The anode-off gas that flows to the one end 52a is discharged into the anode-off gas supply pipe 36b and flows through the anode-off gas supply pipe 36b to be supplied to the combustion section 23. A cross-sectional view of the anode-off gas flow path 36 is omitted, but the flat portions of the groove bottoms of the first flow channel groove 52 and the third flow channel groove 62 are formed to overlap each other. Therefore, the pressure loss when anode-off gas flows through the connecting portion of the first flow channel groove 52 and the third flow channel groove 62 can be reduced. On the other hand, the anode-off gas that flows to the other end 52b flows through the return piping 38 and is returned to the raw fuel gas supply pipe 31a. In this way, the flow channel can be branched and discharged into two pipes, the anode-off gas supply pipe 36b and the return piping 38. Furthermore, even when branching the flow channel, it can be formed in a space equal to the height (thickness) of the first flow channel groove 52 and the third flow channel groove 62, and no separate parts such as branching joints are required. Therefore, it is possible to save space and reduce the number of parts.
[0036] In the fuel cell module 10 of this embodiment described above, the flow path forming section 50 is constructed by overlapping a lower plate 51 and an upper plate 61 such that a portion of the first flow path groove 52 and the third flow path groove 62 overlap each other, and a portion of the second flow path groove 53 and the fourth flow path groove 63 overlap each other. Therefore, it is only necessary to secure space for the overlapping portions of each flow path groove, eliminating the need to bend the piping or to consider the space required for the bending radius of the piping, thus reducing the number of parts. Consequently, the bending portions of the anode off-gas and cathode off-gas flow paths can be configured with a reduced number of parts while avoiding layout and processing problems, resulting in a compact configuration that reduces costs.
[0037] Furthermore, since the flow path forming section 50 is formed such that the flat portions of the groove bottoms face each other and overlap as part of each flow path groove, it prevents the flow path in the connecting section from narrowing and reduces pressure loss when off-gas flows through it.
[0038] Furthermore, gaskets 70 are positioned in the flow path forming section 50 at locations corresponding to each connection port (54, 55, 64, 65). Each gasket 70 is sandwiched between the flange-shaped peripheral portions of the lower plate 51 and the upper plate 61 and the flange portions of each pipe. Therefore, flange rigidity can be ensured by overlapping the lower plate 51 and the upper plate 61, thereby improving sealing performance.
[0039] Furthermore, the flow path forming section 50 is configured such that a third flow path groove 62 is connected to the middle of the first flow path groove 52, and the anode off gas flowing through the third flow path groove 62 is branched to one end 52a and the other end 52b of the first flow path groove 52. Therefore, not only the bend in the anode off gas flow path but also the branching of the flow path is formed, which helps to save space and reduce the number of parts. Also, since one flow path forming section 50 forms part of the anode off gas flow path 36 and part of the cathode off gas flow path 37, the number of parts can be reduced and space can be saved. In addition, by arranging the flow path forming section 50 between the fuel cell stack 11 and the combustion section 23, the fuel cell module 10 can be made compact. Furthermore, since the flow path forming section 50 can be connected to protective tubes for various sensors (protective tube 18 for the temperature sensor) and return piping 38, it can be configured with a high degree of flexibility in connections.
[0040] In this embodiment, a single flow path forming section 50 forms a portion of the anode off-gas flow path 36 and a portion of the cathode off-gas flow path 37, but it is not limited to this. That is, the flow path forming section that forms a portion of the anode off-gas flow path 36 and the flow path forming section that forms a portion of the cathode off-gas flow path 37 may be configured separately. Also, although the flow path forming section forms a portion of the off-gas flow path, it is not limited to this, and may also form flow paths for other gases such as anode gas and cathode gas. The fuel cell module may have multiple such flow path forming sections. Furthermore, the flow path forming section 50 is not limited to being located between the fuel cell stack 11 and the combustion section 23, but may be located in a different location.
[0041] In this embodiment, the first channel groove 52 is formed as a branch channel groove, but it is not limited to this, and a branch channel groove does not need to be formed. That is, the other end 52b of the first channel groove 52 and the other end 62b of the third channel groove 62 are connected, so that the anode-off gas flowing through the first channel groove 52 is discharged to the anode-off gas supply pipe 36b without being branched. Also, as an example of the flow between the channel grooves, the flat portions of the groove bottoms are shown to be facing each other and overlapping, but it is not limited to this. The flow between the channel grooves only needs to be connected in a way that at least a part of it overlaps so that gas can flow through them.
[0042] In this embodiment, a sealing member such as a gasket 70 is provided, but the invention is not limited to this, and a sealing member may not be provided. Also, although each connection port (54, 55, 64, 65) is connected to each pipe by flange connection, it may be connected by other methods such as welding.
[0043] The correspondence between the main elements of the embodiment and the main elements of the disclosure described in the section on the main elements of the embodiment and the means for solving the problems will be explained. The fuel cell stack 11 of the embodiment corresponds to the "fuel cell" of the disclosure, the combustion section 23 corresponds to the "combustion section", the flow path forming section 50 corresponds to the "flow path forming section", and the lower plate 51 and upper plate 61 correspond to "two plate materials". The gasket 70 corresponds to the "sealing member". The first flow path groove 52 corresponds to the "branch flow path groove". The upper plate 61 is referred to as the mating plate material with respect to the lower plate 51, and the lower plate 51 is referred to as the mating plate material with respect to the upper plate 61.
[0044] This specification also discloses a technical concept in which "the fuel cell module described in claim 1 or 2" in the original claim 4 was changed to "the fuel cell module described in any one of claims 1 to 3," and a technical concept in which "the fuel cell module described in claim 1 or 2" in the original claim 5 was changed to "the fuel cell module described in any one of claims 1 to 4."
[0045] Furthermore, the correspondence between the main elements of the embodiments and the main elements of the disclosure described in the section on means for solving the problems is merely an example to specifically explain the form in which the embodiments implement the disclosure described in the section on means for solving the problems, and does not limit the elements of the disclosure described in the section on means for solving the problems. In other words, the interpretation of the disclosure described in the section on means for solving the problems should be based on the description in that section, and the embodiments are merely one specific example of the disclosure described in the section on means for solving the problems.
[0046] The above describes the forms for implementing this disclosure, but this disclosure is not limited in any way to these embodiments, and it is of course possible to implement it in various forms without departing from the gist of this disclosure. [Industrial applicability]
[0047] This disclosure can be used in industries such as the manufacturing of fuel cell modules. [Explanation of symbols]
[0048] 10 Fuel cell module, 11 Fuel cell stack, 12 Evaporator, 15 Module case, 18 Protective tube, 20 Reforming unit, 22 Reforming section, 23 Combustion section, 24 Air heat exchange section, 24a Combustion exhaust gas flow section, 24b Air flow section, 31 Supply pipe, 31a Raw fuel gas supply pipe, 31b Reformed water supply pipe, 32 Mixed gas supply pipe, 33 Anode gas piping, 34 Air supply pipe, 35 Cathode gas piping, 36 Anode off-gas flow path, 36a Anode off-gas discharge pipe, 36b Anode off-gas supply pipe, 37 Cathode off-gas flow path, 37a Cathode off-gas discharge pipe, 37b Cathode off-gas supply pipe, 37f Flange section, 37h Fastening hole, 38 Recirculation piping, 39 Combustion exhaust gas piping, 40 Condenser, 50 Flow path forming section, 51 Bottom plate, 52 53 First channel groove, 54 Second channel groove, 55 First connection port, 58 Second connection port, 58 Fastening hole, 61 Top plate, 62 Third channel groove, 63 Fourth channel groove, 64 Third connection port, 65 Fourth connection port, 66 Fifth connection port, 67 Mounting port, 68 Fastening hole, 70 Gasket.
Claims
1. A fuel cell that generates electricity based on anode gas and cathode gas, A combustion section for burning off-gas from the fuel cell, A flow path forming section that forms a part of the flow path for at least one of the anode gas, cathode gas, and off-gas, Equipped with, The flow path forming section comprises two plate materials, each having a connection port through which a gas pipe forming a flow path for any of the gases can be connected, and a flow path groove recessed in a concave shape relative to the mating surface. The mating surfaces of the two plate materials are superimposed such that the flow path groove communicates with the connection port of the mating plate material and a portion of the flow path grooves overlap each other. Fuel cell module.
2. The channel forming section is such that the channel grooves are formed such that the flat portions of the groove bottoms overlap each other and face each other, as part of the channel grooves. The fuel cell module according to claim 1.
3. The flow path forming portion has multiple fastening holes formed in each of the two plate materials around the connection port and around the flow path groove of the mating plate material communicating with the connection port, which are interconnected and fastened with a fastening member, and an annular sealing member having a through hole corresponding to the connection port is positioned between the flange portion of the gas pipe and the plate material. A fuel cell module according to claim 1 or 2.
4. The aforementioned flow channel forming section is One of the two plates has a flow channel groove formed therein, one end of which communicates with the connection port of the other plate, and at least two connection ports are formed therein. In the other of the two plates, a branching channel groove is formed, which has both ends communicating with the two connection ports of the mating plate and also communicates with the other end of the channel groove of the mating plate midway through the channel, thereby branching the gas that has flowed through the channel groove of the mating plate and discharging it from each of the two connection ports. A fuel cell module according to claim 1 or 2.
5. The combustion section is located above the fuel cell. The flow path forming section has the two plate materials positioned vertically between the fuel cell and the combustion section. The lower plate material has a first flow channel groove and a second flow channel groove formed therein as the flow channel grooves, and a first connection port to which the discharge pipe for anode off-gas discharged from the fuel cell is connected, and a second connection port to which the discharge pipe for cathode off-gas discharged from the fuel cell is connected, The upper plate material has a third flow channel groove that communicates with the first connection port and partially overlaps with the first flow channel groove, and a fourth flow channel groove that communicates with the second connection port and partially overlaps with the second flow channel groove, and the connection port has a third connection port to which a supply pipe for supplying anode off gas to the combustion section is connected and which communicates with the first flow channel groove, and a fourth connection port to which a supply pipe for supplying cathode off gas to the combustion section is connected and which communicates with the second flow channel groove. A fuel cell module according to claim 1 or 2.