JP2024049874A - Fuel Cell Module - Google Patents

Abstract

[Problem] To provide a configuration in which the number of parts is reduced while avoiding layout and workability problems at the bent portion of the gas flow path. [Solution] A fuel cell module includes a fuel cell that generates electricity based on anode gas and cathode gas, a combustion section that combusts off-gas from the fuel cell, and a flow path forming section that forms a part of the flow path of at least one of the anode gas, cathode gas, and off-gas, the flow path forming section including a connection port through which a gas pipe that forms the flow path of one of the gases passes so as to be connectable, and two plate materials each having a flow path groove that is recessed into the mating surfaces, and the mating surfaces of the two plate materials are overlapped so that the flow path groove communicates with the connection port of the other plate material and the flow path grooves partially overlap each other. [Selected Figure] Figure 8

Description

This disclosure relates to a fuel cell module.

Conventionally, a fuel cell module has been proposed that includes a fuel cell that generates electricity based on anode gas (fuel gas) and cathode gas (air), a reformer that generates anode gas by steam reforming raw fuel gas, a combustion section that heats the reformer by burning anode off-gas discharged from the fuel cell, and an evaporator that generates steam by performing heat exchange between the combustion exhaust gas discharged from the combustion section and reforming water. For example, the fuel cell module of Patent Document 1 is provided with a mixed gas supply pipe for supplying a mixed gas of the raw fuel gas and the steam generated in the evaporator to the reformer. One end of the mixed gas supply pipe is connected to the reformer, extends from there approximately horizontally, then bends at a right angle and extends vertically, and the other end is connected to the evaporator.

Patent Document 2 describes a heat exchanger for heating or cooling fluids such as gases and liquids, in which flow channels are formed by joining flow channel plates, each of which has a flow channel groove formed by press processing. The flow channel plates are provided with pipe-shaped inlets and outlets that communicate with the flow channel grooves.

JP 2016-51508 A JP 2015-64132 A

As in Patent Document 1, in fuel cell modules, the flow paths for various gases are formed using pipes, but the ductility of pipe materials that can be used in high-temperature environments is relatively low, so the bending radius of the pipes needs to be large. For this reason, problems with layout and workability can arise in areas that require bending, such as at right angles. It is also possible to form the flow paths using flow path plates, as in Patent Document 2, but this increases the number of parts, such as requiring separate parts to connect the pipes to the pipe-shaped inlets and outlets.

The primary objective of this disclosure is to configure the bent portion of the gas flow path with a reduced number of parts while avoiding layout and workability issues.

This disclosure takes the following steps to achieve the above-mentioned primary objective:

The fuel cell module of the present disclosure comprises:
a fuel cell that generates electricity based on an anode gas and a cathode gas;
a combustion section that combusts off-gas from the fuel cell;
a flow passage forming portion that forms a part of a flow passage for at least one of the anode gas, the cathode gas, and the off-gas;
Equipped with
The flow path forming portion includes two plate materials each having a connection port through which a gas pipe forming a flow path of one of the gases can be connected and a flow path groove recessed into the mating surfaces, and the mating surfaces of the two plate materials are overlapped with each other so that the flow path groove communicates with the connection port of the other plate material and portions of the flow path grooves overlap each other.

In the fuel cell module of the present disclosure, the flow path forming section includes 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, and the two plate materials are overlapped so that the flow path groove communicates with the connection port of the other plate material and the flow path grooves partially 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 so that gas can flow through the flow path forming section. Therefore, it is only necessary to secure the space for the overlapping portion of the flow path grooves, so there is no need to bend the pipe or to consider the space required for the bending radius of the pipe. In addition, by overlapping two plate materials, the strength of the flange portion of the connection port can be ensured while reducing the number of parts. Therefore, the bent portion of the gas flow path can be configured to reduce the number of parts while avoiding problems with layout and workability.

In the fuel cell module of the present disclosure, the flow passage forming portion may be such that the flow passage grooves are formed as part of each other such that the flat portions of the groove bottoms face and overlap each other. This prevents the flow passages at the communicating portions between the flow passage grooves from narrowing, thereby reducing pressure loss when gas flows.

In the fuel cell module of the present disclosure, the flow path forming portion may be such that a plurality of fastening holes are formed in each of the two plate materials around the connection port and around the flow path groove of the mating plate material that communicates with the connection port, the fastening holes being fastened with fastening members so as to penetrate the plate material so as to communicate with each other, and an annular sealing member having a through hole corresponding to the connection port is disposed so as to be sandwiched between the flange portion of the gas pipe. In this way, the plate thickness can be increased by the two plate materials to ensure flange rigidity, thereby improving sealing performance.

In the fuel cell module of the present disclosure, the flow path forming portion may be such that, in one of the two plate materials, the flow path groove is formed, one end of which is connected to the connection port of the mating plate material, and at least two connection ports are formed as the connection port, and in the other of the two plate materials, a branch flow path groove is formed, the both ends of which are connected to the two connection ports of the mating plate material, and the branch flow path groove is formed in the middle of the flow path, and the gas that has flowed through the flow path groove of the mating plate material is branched and discharged from each of the two connection ports. In this way, not only is it possible to form a bent portion of the flow path, but it is also possible to branch the flow path as necessary, thereby saving space.

In the fuel cell module of the present disclosure, the combustion section may be disposed above the fuel cell, and the flow path forming section may include two plates disposed one above the other between the fuel cell and the combustion section. The lower plate may have a first flow path groove and a second flow path groove formed as the flow path grooves, and a first connection port to which an exhaust piping for anode offgas discharged from the fuel cell is connected and a second connection port to which an exhaust piping for cathode offgas discharged from the fuel cell is connected as the connection ports. The upper plate may have a third flow path groove communicating with the first connection port and communicating with the first flow path groove so as to overlap a portion thereof, and a fourth flow path groove communicating with the second connection port and communicating with the second flow path groove so as to overlap a portion thereof, and the connection ports may be a third connection port to which a supply piping for supplying anode offgas to the combustion section is connected and communicating with the first flow path groove, and a fourth connection port to which a supply piping for supplying cathode offgas to the combustion section is connected and communicating with the second flow path groove as the connection ports. In this way, a single flow path forming section forms the flow paths for the anode off-gas and the cathode off-gas, reducing the number of parts and saving space. In addition, by locating the flow path forming section between the fuel cell and the combustion section, the fuel cell module can be configured in a compact manner.

1 is an external perspective view of a fuel cell module 10. FIG. FIG. 2 is a side view of the fuel cell module 10. 1 is a schematic diagram of a fuel cell module 10. FIG. FIG. 2 is an external perspective view of a flow passage forming portion 50. FIG. 4 is a schematic diagram of a lower plate 51. FIG. 4 is a schematic diagram of an upper plate 61. 3 is a partial enlarged view of a flow path forming portion 50. FIG. 3 is a partial cross-sectional view of a flow path forming portion 50. FIG. 5 is an explanatory diagram showing a state in which gas flows in a flow passage forming portion 50. FIG.

Next, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is an external perspective view of a fuel cell module 10. FIG. 2 is a side view of the fuel cell module 10. FIG. 3 is a schematic diagram of the fuel cell module 10. As shown in the figure, the fuel cell module 10 includes a fuel cell stack 11, an evaporation section 12, a reforming unit 20, a condenser 40, and a flow path forming section 50. The fuel cell stack 11 generates power by an electrochemical reaction between hydrogen in the anode gas and oxygen in the cathode gas. The evaporation section 12 evaporates reforming water to generate steam. The reforming unit 20 reforms raw fuel gas (e.g., natural gas or LP gas) by steam reforming to generate anode gas. The fuel cell stack 11, the evaporation section 12, the reforming unit 20, and the flow path forming section 50 are housed in a box-shaped module case 15 having thermal insulation properties. The condenser 40 is installed outside the module case 15. The flow path forming section 50 is disposed between the reforming unit 20 and the fuel cell stack 11.

The fuel cell module 10, together with a raw fuel gas supply device, a reforming water supply device, an air supply device, and a hot water storage tank (not shown), constitutes a fuel cell system. The raw fuel gas supply device supplies raw fuel gas to the evaporation section 12 through a raw fuel gas supply pipe 31a. The reforming water supply device supplies reforming water required for reforming the raw fuel gas into anode gas (steam reforming) to the evaporation section 12 through a reforming water supply pipe 31b. The air supply device supplies air as cathode gas to the fuel cell stack 11 through an air supply pipe 34. The hot water storage tank recovers heat generated by the fuel cell module 10 and stores it in hot water.

The fuel cell stack 11 includes multiple solid oxide type single cells, each of which has an electrolyte such as zirconium oxide and an anode and a cathode that sandwich the electrolyte. An anode gas flow path is connected to the anode of each single cell. A cathode gas flow path is connected to the cathode of each single cell.

The evaporator 12 is connected to a supply pipe 31 connected to a raw fuel gas supply pipe 31a and a reforming water supply pipe 31b. The raw fuel gas supplied from the raw fuel gas supply device to the raw fuel gas supply pipe 31a and the reforming water supplied from the reforming water supply device to the reforming water supply pipe 31b are introduced from the supply pipe 31 to the evaporator 12. The evaporator 12 is filled with a plurality of spherical heat storage members having high thermal conductivity, and when the reforming water flows into the heat storage member in a heated state, the reforming water is evaporated to generate water vapor. The heat storage member is made of a material such as alumina or stainless steel (e.g., ferritic stainless steel). The evaporator 12 preheats the raw fuel gas by introducing the raw fuel gas. The mixed gas of the water vapor and the preheated raw fuel gas generated in the evaporator 12 is supplied to the reforming unit 20 (reformer 22) through the mixed gas supply pipe 32.

The reforming unit 20 is formed in a substantially cylindrical shape as shown in Figs. 1 and 2, and as shown in Fig. 3, the reforming section 22, the combustion section 23, and the air heat exchange section 24 are integrally housed. 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 cylindrical shape with a bottom and are arranged concentrically. An igniter 25 is provided in the center of the upper wall of the reforming unit 20, which extends into the combustion section 23 and serves to ignite the combustion section 23. The evaporation section 12 is formed separately from the reforming unit 20. In Fig. 3, the evaporation section 12 is arranged to the side of the reforming unit 20, but it may be arranged above the reforming unit 20.

The combustion section 23 is supplied with anode off-gas as fuel and cathode off-gas containing oxygen from the bottom. Although not shown, the combustion section 23 has a fuel nozzle that injects the anode off-gas and a supply tube that is cylindrically shaped to surround the fuel nozzle and supplies the cathode off-gas.

The reforming section 22 is formed in a cylindrical shape with a bottom, and a Ru-based or Ni-based reforming catalyst (not shown) is disposed in the internal space with the outer wall of the combustion section 23 as the inner wall. The reforming section 22 also has a supply port connected to the mixed gas supply pipe 32 provided in the upper wall, and the mixed gas (raw fuel gas and steam) passing through the mixed gas supply pipe 32 is supplied from the supply port to the internal space. In the presence of heat from the combustion section 23, the reforming section 22 generates hydrogen gas and carbon monoxide by a reaction (steam reforming reaction) of the mixed gas by the reforming catalyst. Furthermore, the reforming section 22 generates hydrogen gas and carbon dioxide by a reaction (carbon monoxide shift reaction) between the carbon monoxide generated in the steam reforming reaction and the steam. As a result, the reforming section 22 generates an anode gas containing hydrogen, carbon monoxide, carbon dioxide, steam, unreformed raw fuel gas, etc. The reforming section 22 has an exhaust port connected to the anode gas pipe 33 provided in the bottom wall, and the generated anode gas flows from the exhaust port through the anode gas pipe 33 into the anode gas flow path of each unit cell of the fuel cell stack 11 and is supplied to the anode.

The air heat exchanger 24 has a combustion exhaust gas flow section 24a formed in a cylindrical shape with a bottom, through which the combustion exhaust gas generated in the combustion section 23 flows, and an air flow section 24b formed in a cylindrical shape with a bottom, 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 exhaust port 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 exhaust port is supplied to the evaporation section 12 through the combustion exhaust gas piping 39, and is heat exchanged with the reforming water and raw fuel gas in the evaporation section 12 before being supplied to the condenser 40.

The air flow section 24b has a supply port formed in the upper wall to which the air supply pipe 34 of the air supply device is connected, and an exhaust port formed in the side wall to which the cathode gas pipe 35 is connected, forming an internal space with the outer wall of the combustion exhaust gas flow section 24a as the inner wall. The air flowing through the air flow section 24b is heated by heat exchange with the combustion exhaust gas flowing through the combustion exhaust gas flow section 24a. The air that flows through the air heat exchange section 24 and is discharged from the exhaust port flows as cathode gas through the cathode gas pipe 35 into the cathode gas flow path of each single cell of the fuel cell stack 11 and is supplied to the cathode.

Oxide ions (O ^2- ) are generated at the cathode of each unit cell, and these oxide ions pass through the electrolyte and react with hydrogen and carbon monoxide at the anode to generate electrical energy. An input terminal of a power conditioner is connected to the output terminal of the fuel cell stack 11, and the power generated by the fuel cell stack 11 is converted to AC power by the power conditioner and supplied to an electrical load.

The anode gas (hereinafter referred to as "anode off-gas") that was not used in the electrochemical reaction (power generation) in each unit cell is supplied to the combustion section 23 through the anode off-gas flow passage 36. The cathode gas (hereinafter referred to as "cathode off-gas") that was not used in the electrochemical reaction (power generation) in each unit cell is supplied to the combustion section 23 through the cathode off-gas flow passage 37. The anode off-gas flow passage 36 and the cathode off-gas flow passage 37 are partially formed by the flow passage forming section 50, and will be described in detail later. The anode off-gas is a combustible gas containing fuel components such as hydrogen and carbon monoxide, and is mixed with the cathode off-gas containing oxygen in the combustion section 23. The igniter 25 then ignites the mixed gas of the anode off-gas and the cathode off-gas to burn the mixed gas. The mixed gas is burned to generate heat necessary for the operation of the fuel cell stack 11, preheating the raw fuel gas and generating steam in the evaporation section 12, and the steam reforming reaction in the reforming section 22.

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, and then passes through the combustion exhaust gas piping 39 and the evaporation section 12. The combustion exhaust gas is supplied with the heat required for steam reforming, the heat required for raising the temperature of the cathode gas (air), and the heat required for generating water vapor, and is then supplied to the condenser 40. The combustion exhaust gas supplied to the condenser 40 is then cooled by heat exchange with hot water from the hot water storage tank, and at least a portion of the water vapor contained in the combustion exhaust gas is removed, and the gas is then discharged into the atmosphere. The water obtained by condensing the water vapor contained in the combustion exhaust gas is stored in a reforming water tank and used as reforming water.

The configuration of the flow path forming unit 50 will be described below. FIG. 4 is an external perspective view of the flow path forming unit 50. FIG. 5 is a schematic diagram of the lower plate 51. FIG. 6 is a schematic diagram of the upper plate 61. FIG. 7 is a partial enlarged view of the flow path forming unit 50. FIG. 8 is a partial cross-sectional view of the flow path forming unit 50. The flow path forming unit 50 forms, for example, a crank-shaped bent portion as a bending portion of the anode off-gas flow path 36 and the cathode off-gas flow path 37. Note that FIG. 8 illustrates a partial cross-sectional view of the cathode off-gas flow path 37 formed by the flow path forming unit 50. The flow path forming unit 50 is configured by overlapping two plates formed by pressing metal plates such as ferritic stainless steel, and the two plates are bonded together by welding (for example, laser welding) or the like to ensure airtightness. The flow path forming unit 50 is arranged between the fuel cell stack 11 and the combustion unit 23, with the two plates arranged vertically so that, for example, the mating surfaces are horizontal.

As shown in Figs. 4 and 5, the lower plate 51, which is the lower plate material, is formed with a first flow groove 52, a second flow groove 53, a first connection port 54, a second connection port 55, and a plurality of fastening holes 58. The first flow groove 52 and the second flow groove 53 are flow grooves that are recessed in a concave shape with respect to the mating surface of the lower plate 51 (the upper surface in Fig. 5). The first flow groove 52 is formed so as to bend in a substantially crank shape in a top view from one end 52a side to the other end 52b side. The second flow groove 53 is formed in a straight line from one end 53a side to the other end 53b side.

The first connection port 54 and the second connection port 55 are circular through-holes that penetrate the lower plate 51. The first connection port 54 is flange-connected to the anode off-gas exhaust pipe 36a (exhaust pipe) through which the anode off-gas is exhausted from the fuel cell stack 11. Note that the flanges of each pipe are omitted in FIG. 4. The first connection port 54 is also called the first communication port because it is connected to the anode off-gas exhaust pipe 36a by flange connection. Similarly, the second connection port 55 and the third and fourth connection ports 64 and 65 described later are also called the second communication port, the third communication port, and the fourth communication port. The second connection port 55 is flange-connected to the cathode off-gas exhaust pipe 37a (exhaust pipe) through which the cathode off-gas is exhausted from the fuel cell stack 11. 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 52, and one end 53a of the second flow channel 53.

As shown in Figs. 4 and 6, the upper plate 61, which is the upper plate material, is formed with a third flow groove 62, a fourth flow groove 63, a third connection port 64, a fourth connection port 65, a fifth connection port 66, an attachment port 67, and a plurality of fastening holes 68. The third flow groove 62 and the fourth flow groove 63 are flow grooves that are recessed in a concave shape with respect to the mating surface of the upper plate 61 (the lower surface in Fig. 6). The third flow 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 and communicates with the first flow groove 52 so as to overlap a part of it in the middle. The fourth flow 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 and communicates with the other end 53b of the second flow groove 53 so as to overlap a part of it.

The third connection port 64 and the fourth connection port 65 are circular through-holes that penetrate the upper plate 61. The third connection port 64 is flange-connected to the anode off-gas supply pipe 36b (supply pipe) that supplies the anode off-gas to the combustion section 23. The third connection port 64 is also connected to one end 52a of the first flow groove 52 of the lower plate 51. The fourth connection port 65 is flange-connected to the cathode off-gas supply pipe 37b (supply pipe) that supplies the cathode off-gas to the combustion section 23. The fourth connection port 65 is also connected to one end 53a of the second flow groove 53 of the lower plate 51. The fifth connection port 66 is connected to the return pipe 38 for returning a portion of the anode off-gas to the raw fuel gas supply pipe 31a. The fifth connection port 66 is also connected to the other end 53b of the second flow groove 53 of the lower plate 51. The mounting port 67 is formed through the bottom surface of one end of the fourth flow channel 63, and a protective tube 18 for a temperature sensor for measuring the temperature of the cathode off-gas is attached to it.

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 groove 62, and one end 63a of the fourth flow groove 63. Each fastening hole 68 is formed at a position that communicates with each fastening hole 58 when the lower plate 51 and the upper plate 61 are overlapped. Note that each fastening hole 58, 68 may be formed by penetrating the lower plate 51 and the upper plate 61 in a state where they are overlapped.

In addition, the flow path forming part 50 is provided with a gasket 70, which is an annular sealing member, at a position corresponding to each connection port (54, 55, 64, 65). The gasket 70 shown in FIG. 7 is arranged at a position where the central through hole corresponds to the second connection port 55 of the lower plate 51, and is sandwiched between the flange portion 37f (see FIG. 8) of the cathode off-gas exhaust pipe 37a and the flange-shaped portion (peripheral portion) around the second connection port 55. Note that FIG. 8 shows a state where the flange portion 37f of the cathode off-gas exhaust pipe 37a and the flow path forming part 50 (lower plate 51) are separated, but the gasket 70 is sandwiched by fastening using a fastening member such as a bolt (not shown) inserted into the fastening holes 58, 68 and the fastening hole 37h of the flange portion 37f. As shown in FIG. 8, the gasket 70, whose through hole is disposed at a position 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-shaped portion (peripheral portion) around the fourth connection port 65. Gaskets 70 are also disposed at positions corresponding to the other first connection port 54 and the third connection port 64, and are similarly sandwiched. In this way, each gasket 70 disposed at a position corresponding to each connection port (54, 55, 64, 65) is sandwiched between the flange-shaped peripheral portion of the lower plate 51 and the upper plate 61 and the flange portion of each pipe. Therefore, the flow path forming portion 50 can ensure flange rigidity by overlapping two plates, which doubles the plate thickness, thereby improving sealing performance.

Here, FIG. 9 is an explanatory diagram showing the state of gas flow in the flow path forming section 50. In this FIG. 9 and the above-mentioned FIG. 8, the gas flow is indicated by dotted arrows. The cathode off-gas flows from the cathode off-gas exhaust 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 is supplied to the combustion section 23 through the cathode off-gas supply pipe 37b. The second flow path groove 53 and the fourth flow path groove 63 are connected to each other so as to overlap in part, and as shown in FIG. 8, the flat parts of the groove bottoms are formed to face each other and overlap each other (range A in FIG. 8). The second flow path groove 53 and the fourth flow path groove 63 may extend in the same direction and overlap each other by half or more of their lengths in the longitudinal direction (extension direction). In this way, the second flow groove 53 and the fourth flow groove 63 of the flow path forming part 50 horizontally connect the cathode off-gas exhaust pipe 37a and the cathode off-gas supply pipe 37b that extend parallel to each other in the up-down direction (vertical direction). In this way, the bent part of the flow path is formed in a space equivalent to the height (thickness) of the second flow groove 53 and the fourth flow groove 63, so it is possible to save space compared to forming it by bending the pipe. In addition, since the flat parts of the groove bottoms face each other and overlap each other, it is possible to prevent the flow path of the communication part from narrowing compared to when the flat parts do not face each other, and to reduce the pressure loss when the cathode off-gas flows.

9, the anode off-gas flows from the anode off-gas discharge pipe 36a into the third flow groove 62, and then flows from the third flow groove 62 into the first flow groove 52. As described above, the first flow groove 52 of the lower plate 51 is formed to be bent in an approximately crank shape, and the third flow groove 62 of the upper plate 61 is formed to overlap the middle (bent portion) of the first flow groove 52. Therefore, the anode off-gas that flows into the first flow groove 52 branches into one end 52a and the other end 52b. The anode off-gas that flows to the one end 52a is discharged to the anode off-gas supply pipe 36b, and is supplied to the combustion section 23 through the anode off-gas supply pipe 36b. Although the cross-sectional view of the anode off-gas flow path 36 is omitted, the flat portions of the groove bottoms of the first flow groove 52 and the third flow groove 62 are formed to face each other and overlap each other. This reduces the pressure loss when the anode off-gas flows through the communication portion between the first flow groove 52 and the third flow groove 62. Meanwhile, the anode off-gas that flows to the other end 52b flows through the reflux pipe 38 and is returned to the raw fuel gas supply pipe 31a. In this way, the flow path can be branched and discharged to two pipes, the anode off-gas supply pipe 36b and the reflux pipe 38. In addition, even if the flow path is branched, it can be formed in a space equivalent to the height (thickness) of the first flow groove 52 and the third flow groove 62, and separate parts such as joints for branching are not required. This makes it possible to save space and reduce the number of parts.

In the fuel cell module 10 of this embodiment described above, the flow path forming portion 50 is configured by overlapping the lower plate 51 and the upper plate 61 so that the first flow path groove 52 and the third flow path groove 62 partially overlap each other and the second flow path groove 53 and the fourth flow path groove 63 partially overlap each other. Therefore, it is only necessary to secure space for the overlapping parts of each flow path groove, and there is no need to bend the piping or to consider the space required for the bending radius of the piping, and the number of parts can be reduced. Therefore, the bending parts of the flow paths for the anode off-gas and cathode off-gas can be configured with a reduced number of parts while avoiding layout and workability problems, making it possible to achieve a compact configuration with reduced costs.

In addition, the flow path forming section 50 is formed as part of each flow path groove so that the flat portions of the groove bottoms face each other and overlap, preventing the flow path in the communicating portion from narrowing and reducing the pressure loss when the off-gas flows.

In addition, gaskets 70 are arranged in the flow path forming section 50 at positions corresponding to each connection port (54, 55, 64, 65). Each gasket 70 is sandwiched between the flange-shaped peripheral portion of the lower plate 51 and the upper plate 61 and the flange portion of each pipe. Therefore, by overlapping the lower plate 51 and the upper plate 61, flange rigidity can be ensured and sealing performance can be improved.

The flow passage forming section 50 is formed so that the third flow passage groove 62 is connected to the middle of the first flow passage groove 52, and the anode off-gas flowing through the third flow passage groove 62 is branched to one end 52a side and the other end 52b side of the first flow passage groove 52. Therefore, not only the bent portion of the anode off-gas flow passage but also the branching of the flow passage can be formed, thereby saving space and reducing the number of parts. In addition, since a part of the anode off-gas flow passage 36 and a part of the cathode off-gas flow passage 37 are formed by one flow passage forming section 50, the number of parts can be reduced and space can be saved. In addition, by arranging the flow passage forming section 50 between the fuel cell stack 11 and the combustion section 23, the fuel cell module 10 can be made compact. In addition, the flow passage forming section 50 can be connected to various sensor protection tubes (temperature sensor protection tube 18) and return pipe 38, etc., so that the configuration can be made with a high degree of freedom in connection.

In the embodiment, a single flow path forming section 50 forms a part of the anode off-gas flow path 36 and a part of the cathode off-gas flow path 37, but this is not limited to the above. That is, the flow path forming section that forms a part of the anode off-gas flow path 36 and the flow path forming section that forms a part of the cathode off-gas flow path 37 may be configured separately. In addition, the flow path forming section forms a part of the off-gas flow path, but this is not limited to the above, and the flow path forming section may form a flow path for other gases such as anode gas and cathode gas. The fuel cell module may include multiple such flow path forming sections. In addition, the flow path forming section 50 is not limited to being disposed between the fuel cell stack 11 and the combustion section 23, and may be disposed in another location.

In the embodiment, the first flow groove 52 is formed as a branch flow groove, but this is not limited thereto, and a branch flow groove may not be formed. In other words, the other end 52b side of the first flow groove 52 and the other end 62b side of the third flow groove 62 may be connected to each other, and the anode off-gas that flows through the first flow groove 52 may be discharged to the anode off-gas supply pipe 36b without being branched. In addition, although an example in which the flat portions of the groove bottoms face each other and overlap as part of each flow groove has been shown, this is not limited thereto. It is sufficient that each flow groove is connected to each other by overlapping at least a portion so that gas can flow.

In the embodiment, a sealing member such as a gasket 70 is provided, but this is not limited, and a sealing member may not be provided. Also, each connection port (54, 55, 64, 65) is connected to each pipe by a flange connection, but may be connected by other methods such as welding.

The correspondence between the main elements of the embodiment and the main elements of the present disclosure described in the section on means for solving the problems will be explained. The fuel cell stack 11 of the embodiment corresponds to the "fuel cell" of the present 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 the upper plate 61 correspond to the "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 relative to the lower plate 51, and the lower plate 51 is referred to as the mating plate material relative to the upper plate 61.

This specification also discloses the technical idea of changing "the fuel cell module according to claim 1 or 2" in claim 4 originally filed to "the fuel cell module according to any one of claims 1 to 3" and the technical idea of changing "the fuel cell module according to claim 1 or 2" in claim 5 originally filed to "the fuel cell module according to any one of claims 1 to 4".

The correspondence between the main elements of the embodiment and the main elements of the present disclosure described in the Means for Solving the Problem column does not limit the elements of the present disclosure described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the present disclosure described in the Means for Solving the Problem column. In other words, the interpretation of the present disclosure described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the present disclosure described in the Means for Solving the Problem column.

Although the above describes the forms for implementing this disclosure, this disclosure is in no way limited to these embodiments, and it goes without saying that this disclosure can be implemented in various forms without departing from the spirit of this disclosure.

This disclosure can be used in the fuel cell module manufacturing industry, etc.

10 fuel cell module, 11 fuel cell stack, 12 evaporation section, 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 reforming water supply pipe, 32 mixed gas supply pipe, 33 anode gas pipe, 34 air supply pipe, 35 cathode gas pipe, 36 anode off gas flow path, 36a anode off gas exhaust pipe, 36b anode off gas supply pipe, 37 cathode off gas flow path, 37a cathode off gas exhaust pipe, 37b cathode off gas supply pipe, 37f flange section, 37h fastening hole, 38 return pipe, 39 combustion exhaust gas pipe, 40 condenser, 50 flow path forming section, 51 lower plate, 52 first flow path groove, 53 Second flow groove, 54 first connection port, 55 second connection port, 58 fastening hole, 61 upper plate, 62 third flow groove, 63 fourth flow groove, 64 third connection port, 65 fourth connection port, 66 fifth connection port, 67 mounting port, 68 fastening hole, 70 gasket.

Claims (5)

a fuel cell that generates electricity based on an anode gas and a cathode gas;
a combustion section that combusts off-gas from the fuel cell;
a flow passage forming portion that forms a part of a flow passage for at least one of the anode gas, the cathode gas, and the off-gas;
Equipped with
The flow path forming portion includes two plate materials each having a connection port through which a gas pipe forming a flow path of any one of the gases can be connected and a flow path groove recessed into a mating surface, and the mating surfaces of the two plate materials are overlapped with each other so that the flow path groove communicates with the connection port of the other plate material and parts of the flow path grooves overlap with each other.
Fuel cell module. The flow path forming portion is formed such that flat portions of the groove bottoms face each other and overlap each other as parts of the flow path grooves.
The fuel cell module of claim 1 . The flow path forming portion has a plurality of fastening holes formed in the peripheral portion of the connection port of each of the two plate materials and in the peripheral portion of the flow path groove of the mating plate material communicating with the connection port, the fastening holes penetrating the connection port so as to communicate with each other and fastening with a fastening member, and an annular seal member having a through hole corresponding to the connection port is disposed so as to be sandwiched between the flange portion of the gas pipe.
3. The fuel cell module according to claim 1 or 2. The flow path forming portion is
One of the two plate materials has the flow channel formed therein, one end of which is connected to the connection port of the other plate material, and at least two connection ports are formed as the connection ports;
In the other of the two plate materials, a branch flow channel is formed as the flow channel, the both ends of which are connected to the two connection ports of the mating plate material, respectively, and the branch flow channel is connected to the other end of the flow channel of the mating plate material in the middle of the flow channel, and the gas that has flowed through the flow channel of the mating plate material is branched and discharged from each of the two connection ports.
3. The fuel cell module according to claim 1 or 2. the combustion section is disposed above the fuel cell,
the flow passage forming section is disposed between the fuel cell and the combustion section, and the two plates are disposed one above the other;
the lower plate member has a first flow path groove and a second flow path groove formed as the flow path grooves, and a first connection port to which an exhaust pipe for an anode off-gas discharged from the fuel cell is connected and a second connection port to which an exhaust pipe for a cathode off-gas discharged from the fuel cell is connected as the connection ports;
The upper plate member is formed with the flow grooves including a third flow groove communicating with the first connection port and communicating with a portion of the first flow groove so as to overlap therewith, and a fourth flow groove communicating with the second connection port and communicating with a portion of the second flow groove so as to overlap therewith, and the connection ports include 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 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 groove.
3. The fuel cell module according to claim 1 or 2.

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