JP2010287367A - Power generation module constituting fuel cell - Google Patents

Abstract

The present invention provides a technique for improving the assembly of a power generation module in a fuel cell.
A power generation module is stacked in a fuel cell with the arrangement directions alternately reversed. The power generation module 110 includes two membrane electrode assemblies 11 and 12 and three separators 21 to 23 provided with flow channel grooves for fluid on both sides. The membrane electrode assemblies 11 and 12 and the separators 21 to 23 are alternately arranged and are integrally held by the adhesive seal part 40. On the outer periphery of the adhesive seal portion 40, a protrusion 45 is provided that extends in the thickness direction of the power generation module 110 and projects to the side of the adjacent power generation module 110 when the fuel cell 100 is configured. When the arrangement direction of the adjacent power generation module 110 is not reversed, the protrusion 45 comes into contact with the protrusion 45 provided on the adjacent power generation module 110 to prevent the assembly of the fuel cell.
[Selection] Figure 1

Description

  The present invention relates to a fuel cell.

  A fuel cell usually has a stack structure in which a plurality of power generation modules are stacked (Patent Document 1 below). Each power generation module includes a membrane electrode assembly in which electrodes are arranged on both surfaces of the electrolyte membrane, and separators arranged on both sides of the membrane electrode assembly. Each power generation module of the fuel cell is supplied with a reaction gas such as hydrogen or oxygen or a fluid such as a refrigerant for cooling reaction heat from the outside.

  By the way, when assembling each power generation module as a fuel cell stack, if the arrangement position or the orientation of the power module is shifted, the sealing property of the fluid inside the fuel cell stack is deteriorated or the contact resistance between the power generation modules is increased. There was a case. However, until now, it has been the case that sufficient ingenuity has not been made for these problems.

Japanese Patent No. 3721321 Japanese Patent No. 3968278 Japanese Patent Laid-Open No. 2002-260689

  An object of this invention is to provide the technique which improves the assembly | attachment property of a power generation module in a fuel cell stack.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A power generation module that is stacked to constitute a fuel cell stack, and when stacked, the power generation modules can be stacked in an inverted state rotated 180 ° on a plane perpendicular to the stacking direction with respect to adjacent power generation modules. 2N (N is a natural number) membrane electrode assembly, in which electrodes are arranged on both sides of the electrolyte membrane, and a channel groove for fluid are provided on both sides. 2N + 1 separators, and the 2N membrane electrode assemblies and the 2N + 1 separators are alternately arranged so that each of the 2N membrane electrode assemblies is sandwiched by the separators. In addition, in order to prevent leakage of fluid to the outside, it is integrally held by a seal part provided so as to surround the outer periphery of the power generation module, and the outer periphery of the seal part includes An outermost separator that is provided on the outermost side of the power generation module, is provided with a protrusion that extends in the thickness direction of the power generation module and that projects to the side of the adjacent power generation module when the fuel cell is configured. When the fuel cell stack is configured, the flow channel groove provided on the outer surface of the battery is opposed to the flow channel groove of the outermost separator of the adjacent power generation module in the inverted state for the refrigerant. In the step of stacking a plurality of the power generation modules to form the fuel cell stack, the protrusions are adjacent to each other when the adjacent power generation modules are not arranged in the inverted state. A power generation module configured to contact the protrusion provided on the power generation module and prevent assembly of the fuel cell stack. Le.
According to this power generation module, when configuring the fuel cell stack, if the power generation modules are stacked in the wrong arrangement direction, the protrusions of the power generation module and the protrusions provided in the adjacent power generation modules interfere with each other. Therefore, it can suppress that a power generation module will be arrange | positioned with the incorrect arrangement | positioning direction. Therefore, the assembly property of the power generation module is improved.

  The present invention can be realized in various forms, for example, in the form of a fuel cell stack, a fuel cell system including the fuel cell stack, a vehicle equipped with the fuel cell system, and the like. Can do.

Schematic which shows the structure of a fuel cell. Schematic which shows the structure of an electric power generation module. Schematic which shows the structure of the fuel cell as a comparative example.

A. Example:
FIG. 1 is a schematic diagram showing the configuration of a fuel cell stack (hereinafter also simply referred to as “fuel cell”) as an embodiment of the present invention. The fuel cell 100 is a polymer electrolyte fuel cell that generates power by receiving supply of hydrogen and oxygen as reaction gases. The fuel cell 100 has a stack structure in which a plurality of power generation modules 110 are stacked.

  The power generation module 110 includes two membrane electrode assemblies 11 and 12 and three separators 21, 22, and 23. The membrane electrode assemblies 11, 12 and the separators 21, 22, 23 are alternately stacked. Specifically, the first separator 21, the first membrane electrode assembly 11, the second separator 22, the second membrane electrode assembly 12, and the third separator 23 are stacked in this order.

  Each of the two membrane electrode assemblies 11 and 12 is a power generator in which electrodes (not shown) are provided on both surfaces of a solid polymer thin film that exhibits good proton conductivity in a wet state. Each electrode is preferably provided with a gas diffusion layer for spreading the reaction gas over the entire electrode surface. Each electrode preferably carries a catalyst (for example, platinum (Pt)) for promoting the fuel cell reaction.

  Each of the three separators 21, 22, and 23 is configured by a plate-like member (for example, a metal plate) having gas-impermeable conductivity. Each separator 21, 22, 23 functions as a current collector for collecting electricity generated by each membrane electrode assembly 11, 12. In addition, each separator 21, 22, 23 is bent into a corrugated shape so as to have irregularities. As a result, a plurality of flow channel grooves (concave portions) that run in parallel are formed on both surfaces of each separator 21, 22, 23 with the same number and the same width. In the figure, the depth of the channel groove of the first separator 21 is formed shallower than the depth of the channel groove of the second and third separators 22, and the second and third separators 22, The depth of the channel groove 23 is approximately the same. However, the depths of the channel grooves of the separators 21, 22, and 23 may be all the same or may be all different.

  Here, in the power generation module 110, a flow path for the reaction gas is formed by the flow path grooves of the separators 21, 22 and 23 and the electrode surfaces of the membrane electrode assemblies 11 and 12. Specifically, the first hydrogen channel 31 a is formed by the channel groove of the first separator 21 and the electrode surface of the first membrane electrode assembly 11. In addition, a first oxygen channel 32 a is formed by the first membrane electrode assembly 11 and the channel groove of the second separator 22. Further, a second hydrogen channel 31b is formed by the channel groove of the second separator 22 and the electrode surface of the second membrane electrode assembly 12, and the electrode surface of the second membrane electrode assembly 12 and the third The second oxygen channel 32b is formed by the channel groove of the separator 23. The hydrogen flow paths 31a and 31b and the oxygen flow paths 32a and 32b are preferably configured to face each other with the membrane electrode assembly 11 and 12 interposed therebetween.

  An adhesive seal portion 40 is provided on the outer periphery of the power generation module 110. The adhesive seal part 40 is used to integrally bond and hold the membrane electrode assemblies 11 and 12 and the separators 21, 22, and 23 and to prevent leakage of fluid to the outside of the power generation module 110. Is. The adhesive seal portion 40 may be formed of an adhesive, or may be formed as a seal gasket by injection molding. In addition, it is preferable that the adhesive seal part 40 is non-conductive in order to prevent a short circuit between electrodes.

  The adhesive seal portion 40 is provided with a recess for arranging the gasket 42. The gasket 42 is an annular member for preventing leakage of fluid to the outside of the fuel cell 100 and is disposed at the boundary between the power generation modules 110 adjacent to each other. In addition, this gasket 42 functions also as a positioning part for suppressing that the arrangement position of each power generation module 110 shifts | deviates when each power generation module 110 is laminated | stacked.

  In addition, a protrusion 45 is provided on one side of the outer periphery of the adhesive seal portion 40. The protrusion 45 extends from the first separator 21 side to the third separator 23 side in the thickness direction (stacking direction) of the power generation module 110 and from the boundary between the power generation modules 110 to be stacked. It protrudes by length x. The function of this protrusion 45 will be described later.

  By the way, in this fuel cell 100, a plurality of power generation modules 110 are stacked with their arrangement directions alternately reversed. Specifically, each power generation module 110 is arranged in an inverted state rotated 180 ° on a plane perpendicular to the stacking direction with respect to the adjacent power generation module 110. By being laminated in this way, the convex portions of the first separator 21 and the convex portions of the third separator 23 of the power generation modules 110 are in direct contact with each other. Moreover, the recessed part of the 1st separator 21 and the recessed part of the 3rd separator 23 which mutually oppose each other mutually, and the some flow path 33 which runs side by side is formed. A refrigerant supplied from the outside for cooling the fuel cell 100 flows into the flow path 33. Hereinafter, the flow path 33 is referred to as a “refrigerant flow path 33”.

  FIG. 2 is a schematic cross-sectional view showing a cross section of the fuel cell 100 taken along the line 2-2 in FIG. In FIG. 2, by omitting hatching of the flow channel of the first separator 21, the first separator 21 is distinguished from the convex portion of the first separator 21 when viewed along the direction perpendicular to the paper surface. Further, in FIG. 2, the seal line formed by the gasket 42 is illustrated by a one-dot chain line.

  The adhesive seal portion 40 of each power generation module 110 includes hydrogen supply and discharge manifolds 51 and 52, oxygen supply and discharge manifolds 53 and 54, and refrigerant supply and discharge manifolds 55. , 56 are provided as through holes. In addition, the adhesive seal portion 40 is provided with a seal line that surrounds the manifolds 51 to 56 and a flow path that connects the manifolds 51 to 56 and the fluid flow paths 31 to 33 (FIG. 1). The illustration and description thereof will be omitted. Each manifold 51-56 is good also as what is formed in the size according to the kind of fluid. In the figure, the hydrogen manifolds 51 and 52 are provided in the smallest size, and the refrigerant manifolds 55 and 56 are formed in the largest size, but the manifolds 51 to 56 are formed in other sizes. It may be done.

  Each of the manifolds 51 to 56 is provided so that each of the supply manifolds 51 to 53 and each of the discharge manifolds 54 to 56 face each other across the power generation region. More specifically, the manifolds 51 to 56 are formed in point symmetry with the center of the power generation module 110 as the center of symmetry. Therefore, when the power generation module 110 is rotated 180 ° so as to be reversed in the vertical direction on the paper surface, the positions of the supply manifolds 51 to 53 and the positions of the discharge manifolds 54 to 56 are interchanged. That is, as described above, when the fuel cell 100 is configured, the manifolds 51 to 56 of all the power generation modules 110 are connected even when the arrangement directions of some of the power generation modules 110 are reversed. Is done. In the power generation module 110, in addition to the manifolds 51 to 56, the shape of the power generation region, the shape of the seal line provided in the adhesive seal portion 40, and the like are formed point-symmetrically with the center of the power generation module 110 as the center of symmetry. It is preferable.

  FIG. 3 is a schematic diagram showing a configuration of a fuel cell 100a as a comparative example of the present invention. FIG. 3 is substantially the same as FIG. 1 except that the protrusion 45 is not provided and that all the power generation modules 110 are stacked in the same arrangement direction.

  In the fuel cell 100a of the comparative example, at the boundary between the power generation modules 110, the convex portion of the first separator 21 and the flow channel groove of the third separator 23 face each other, so that the first and third separators 21 and 23 contact each other. Therefore, the refrigerant flow path formed between the power generation modules 110 is divided into the refrigerant flow path 33a on the third separator 23 side and the refrigerant flow path 33b on the first separator 23 side. Therefore, the flow passage cross-sectional area of each refrigerant flow passage 33a, 33b becomes smaller than the flow passage cross-sectional area of the refrigerant flow passage 33 in the fuel cell 100 of the present embodiment, the pressure loss of the refrigerant flowing in increases, and cooling by the refrigerant. Efficiency will decrease. In addition, since the contact area between the first and third separators 21 and 23 is smaller than that of the fuel cell 100 of the present embodiment, the contact resistance between the power generation modules 110 is increased.

  That is, in the fuel cell 100a of this comparative example, the power generation efficiency may be lower than that of the fuel cell 100 of the present embodiment. Therefore, as in the fuel cell 100 of the present embodiment, it is preferable to alternately stack the power generation modules 110 whose arrangement directions are rotated by 180 ° and the power generation modules 110 that are not rotated.

  Here, each power generation module 110 is provided with a protrusion 45, and this protrusion 45 protrudes from the boundary between the adjacent power generation modules 110 by a length x (FIG. 1). Therefore, in the stacking process of the power generation modules 110 for constituting the fuel cell 100, if the stacking is attempted without alternately reversing the arrangement direction of the power generation modules 110, the protrusions 45 of the power generation modules 110 come into contact with each other. Interfere with each other. Therefore, when the fuel cell 100 is assembled, it is possible to prevent the power generation module 110 from being stacked in an incorrect arrangement direction, and the assembly property of the power generation module 110 is improved.

  In addition, it is preferable that the length x that the protrusion 45 projects from the boundary of each power generation module 110 is smaller than the thickness t of the power generation module 110 (0 <x <t). Thereby, it can avoid that the projection part 45 of the power generation modules 110 with the same arrangement direction interferes. Further, the protrusion 45 may be provided with a sensor for detecting contact between the protrusions 45. This further suppresses the occurrence of errors in the arrangement direction of the power generation module 110 and improves the assemblability.

  As described above, according to the power generation module 110 of the present embodiment, the power generation module 110 is stacked in the wrong arrangement position and direction by the gasket 42 and the protrusion 45 in the stacking process when the fuel cell 100 is configured. Can be suppressed. The power generation module 110 includes two membrane electrode assemblies 11 and 12 and three separators 21, 22 and 23, and the fuel cell 100 includes a refrigerant flow path 33 at the boundary between the power generation modules 110. Is provided. Therefore, according to the power generation module 110 of the present embodiment, the fuel cell 100 can be downsized as compared with a fuel cell in which a refrigerant flow path is provided for each membrane electrode assembly. Furthermore, according to the power generation module 110 of the present embodiment, the pressure loss of the refrigerant flow path 33 formed between the power generation modules 110 in the fuel cell 100 and the contact resistance between the power generation modules 110 are reduced. The increase can be suppressed. Accordingly, a decrease in power generation efficiency of the fuel cell 100 can be suppressed.

  Although the power generation module 110 of this example has the two membrane electrode assemblies 11 and 12 and the three separators 21, 22, and 23, the power generation module 110 further includes a plurality of membrane electrode assemblies. It is good also as what has a body and a separator. In other words, the power generation module 110 has 2N (N is a natural number) membrane electrode assemblies and 2N + 1 separators, and alternately the 2N membrane electrode assemblies are sandwiched by the separators. It may be arranged.

DESCRIPTION OF SYMBOLS 11 ... 1st membrane electrode assembly 12 ... 2nd membrane electrode assembly 21 ... 1st separator 22 ... 2nd separator 23 ... 3rd separator 31a ... 1st hydrogen flow path 31b ... 2nd hydrogen Flow path 32a ... First oxygen flow path 33, 33a, 33b ... Refrigerant flow path 40 ... Adhesive seal part 42 ... Gasket 45 ... Projection part 51-56 ... Manifold 100, 100a ... Fuel cell 110 ... Power generation module

Claims (1)

A power generation module that is stacked to constitute a fuel cell stack, and when stacked, the power generation modules can be stacked in an inverted state rotated 180 ° on a plane perpendicular to the stacking direction with respect to adjacent power generation modules. A power generation module configured in
2N (N is a natural number) membrane electrode assemblies, which are power generation bodies in which electrodes are arranged on both surfaces of the electrolyte membrane;
2N + 1 separators provided on both sides with flow channel grooves for fluid;
With
The 2N membrane electrode assemblies and the 2N + 1 separators are alternately arranged so that each of the 2N membrane electrode assemblies is sandwiched between the separators, and fluid leaks to the outside. Is integrally held by a seal portion provided so as to surround the outer periphery of the power generation module,
The outer periphery of the seal portion is provided with a protrusion that extends in the thickness direction of the power generation module and projects to the side of the adjacent power generation module when the fuel cell is configured.
The flow channel groove provided on the outer surface of the outermost separator disposed on the outermost side of the power generation module is the outermost part of the adjacent power generation module in the inverted state when the fuel cell stack is configured. A coolant channel for the coolant is formed opposite to the channel groove of the separator,
In the step of stacking a plurality of the power generation modules to form the fuel cell stack, the protrusion is provided in the adjacent power generation module when the adjacent power generation modules are not arranged in the inverted state. A power generation module configured to contact a protrusion and prevent assembly of the fuel cell stack.

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