JP2011222393A - Fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling efficiency while improving a sealing property of a gas seal part.SOLUTION: A fuel cell is formed by laminating a plurality of single cells, and a coolant passage is formed between separators provided to respective adjacent single cells. A coolant sealing position, at which a coolant passage seal part contacts both of the adjacent separators, is arranged on an outer periphery side of the separator from a gas sealing position, at which a first gas seal convex portion and a second gas convex portion sandwich a membrane/electrode assembly. At least one of a pair of the separators constituting the single cell has an inverted shape, is convexed toward the membrane/electrode assembly, and has a separator convex portion covered by at lest one of the first gas seal convex portion and the second gas seal convex portion. A coolant side flow restraining portion for blocking at least one part of a space formed by a concave portion of an inverted structure of the separator convex portion is provided to the coolant passage.

Description

  The present invention relates to a fuel cell.

  Conventionally, various types of fuel cells have been proposed. In general, a fuel cell in which a membrane-electrode assembly formed by forming an electrode on the surface of an electrolyte membrane is sandwiched between a pair of separators, and a gas flow path is formed between each separator and the membrane-electrode assembly. Is widely known. As one of such fuel cells, one in which a coolant channel for cooling the fuel cell is provided inside a separator formed by laminating a plurality of plates is known (see, for example, Patent Document 1). ).

JP 2008-192400 A JP 2001-185174 A JP 2009-037960 A JP 2008-034383 A

  In a fuel cell, it is important to ensure the sealing performance in the gas flow path formed on the electrode, and various configurations of the sealing portion for ensuring the sealing performance of the gas flow path have been proposed. ing. When the shape of the seal part of such a gas flow path affects the shape of the refrigerant flow path on the back side of the plate-like member that forms the separator and forms the gas flow path on the surface, the structure of the seal part is The cooling efficiency of the refrigerant may be affected. Thus, even when the configuration of the seal part of the gas flow path affects the shape of the refrigerant flow path, the fuel cell as a whole, such as further improving the sealing performance in the seal part and ensuring cooling efficiency, can be obtained. It is desirable to improve performance.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to improve the cooling efficiency of the fuel cell while improving the sealing performance in the gas seal portion.

  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 membrane-electrode assembly including an electrolyte membrane and electrodes formed on both surfaces of the electrolyte membrane, and a gas flow path disposed between the membrane-electrode assembly and the membrane-electrode assembly. A pair of separators, and a fuel cell formed by laminating a plurality of single cells,
A refrigerant flow path forming member that is disposed between the separators of each adjacent single cell and forms a part of a space that becomes a refrigerant flow path;
A gas flow path seal portion disposed between the pair of separators along the outer peripheral portion of the membrane-electrode assembly,
A refrigerant flow path seal portion that is provided so as to be in contact with both separators included in each adjacent single cell and seals the refrigerant flow path; and
With
At least one of the pair of separators has a separator convex portion that is convex to the membrane-electrode assembly side in a shape that is upside down at a position in contact with the gas flow path seal portion,
The gas flow path seal portion is provided by being bonded to one of the pair of separators, and is bonded to the first gas flow path seal member having the first gas seal convex portion and the other of the pair of separators. And a second gas flow path seal member having a second gas seal convex portion, and the membrane-electrode assembly is formed by the first gas seal convex portion and the second gas seal convex portion. By sandwiching, seal the gas flow path formed on both surfaces of the membrane-electrode assembly,
At least one of the first gas seal convex portion and the second gas seal convex portion is formed in a shape along the separator convex portion,
The refrigerant seal position where the refrigerant flow path seal portion contacts both of the adjacent separators is the gas seal position where the first gas seal convex portion and the second gas seal convex portion sandwich the membrane-electrode assembly. Than the outer peripheral side of the separator,
The fuel flow path is provided with a refrigerant side flow suppressing portion that closes at least a part of a space formed by a concave portion that is a reverse structure of the separator convex portion.

  According to the fuel cell described in Application Example 1, since at least one of the first gas seal convex portion and the second gas seal convex portion is arranged so as to overlap the separator convex portion, the gas flow path The gas sealing property in the seal portion can be enhanced. Moreover, since the position of the refrigerant seal is arranged on the outer peripheral side of the gas separator with respect to the gas seal position, the entire region where the gas flows and an electrochemical reaction can occur can be efficiently cooled by the refrigerant. In such a fuel cell, since the refrigerant side flow suppressing portion that closes at least a part of the space formed by the concave portion that is the reverse structure of the separator convex portion is provided, the separator convex portion is provided to improve the gas sealing performance. This can suppress an increase in the side flow of the refrigerant in the refrigerant flow path. By suppressing the side flow of the refrigerant, the flow rate of the refrigerant flowing in the refrigerant flow path forming portion can be relatively increased, so that the cooling efficiency of the fuel cell by the refrigerant can be improved.

[Application Example 2]
The fuel cell according to application example 1, wherein the refrigerant side flow suppressing portion is formed of an independent member fitted in the recess. According to the fuel cell of the application example 2, it is possible to increase the degree of freedom in selecting the material constituting the refrigerant side flow suppressing unit.

[Application Example 3]
The fuel cell according to Application Example 1, wherein the refrigerant side flow suppressing portion has a reverse structure of the separator convex portion in a separator adjacent to the separator formed with the separator convex portion via the refrigerant flow path. A fuel cell, which is a protrusion provided to be convex with respect to the concave surface of the concave portion. According to the fuel cell described in Application Example 3, since the refrigerant side flow suppressing portion is formed integrally with the separator, an increase in the number of parts due to the provision of the refrigerant side flow suppressing portion can be suppressed. Furthermore, when assembling the fuel cell, it is only necessary to fit the protruding portion, which is a refrigerant side flow suppressing portion provided in the separator, into the concave portion of the adjacent separator, so that alignment between the separators can be facilitated.

[Application Example 4]
The fuel cell according to Application Example 1, wherein the refrigerant side flow suppressing portion is formed integrally with the refrigerant flow path seal portion. According to the fuel cell described in Application Example 4, since the refrigerant side flow suppressing portion is formed integrally with the refrigerant flow path seal portion, an increase in the number of parts due to the provision of the refrigerant side flow suppressing portion can be suppressed.

[Application Example 5]
The fuel cell according to Application Example 1, wherein the refrigerant side flow suppressing portion is formed by extending a part of an outer periphery of the refrigerant flow path forming member. According to the fuel cell described in Application Example 5, since the refrigerant side flow suppressing portion is formed integrally with the refrigerant flow path forming portion, an increase in the number of parts due to the provision of the refrigerant side flow suppressing portion can be suppressed. Furthermore, when assembling the fuel cell, the refrigerant side flow suppressing portion provided in the refrigerant flow path forming portion only needs to be fitted into the recess of the separator, so that the operation of laminating the refrigerant flow passage forming portion with respect to the separator is performed. Can be facilitated.

[Application Example 6]
The fuel cell according to any one of Application Examples 1 to 5, wherein the concave portion provided with the refrigerant side flow suppressing portion is between an outer periphery of the refrigerant flow path forming member and the refrigerant flow path seal portion. A fuel cell provided at a position spaced apart from an inflow portion of the refrigerant into the refrigerant passage and an outflow portion of the refrigerant from the refrigerant passage. According to the fuel cell described in Application Example 6, the side flow of the refrigerant is a gap between the refrigerant flow path forming portion and the refrigerant flow path seal portion, and is generated at a position separated from the refrigerant inflow portion and the outflow portion. Therefore, the side flow in the refrigerant channel can be effectively suppressed.

[Application Example 7]
The fuel cell according to any one of Application Examples 1 to 6,
The first and second gas seal convex portions are formed so as to surround the entire outer periphery of a power generation region where an electrochemical reaction proceeds in the membrane-electrode assembly,
The first gas seal member includes an inflow portion of the first gas into a first gas flow path formed between one of the pair of separators and the membrane-electrode assembly, and In the outflow part of the first gas from the first gas flow path, a first communication hole serving as a passage for the first gas is formed,
The second gas seal member includes an inflow portion of the second gas into a second gas flow path formed between the other of the pair of separators and the membrane-electrode assembly, and A second communication hole serving as a passage for the second gas is formed in an outflow portion of the second gas from the second gas flow path.

  According to the fuel cell described in Application Example 7, the inflow and outflow of gas into the gas flow path can be ensured by the first and second communication holes. At this time, in order to seal the gas flow path by sandwiching the membrane-electrode assembly by the first and second gas seal projections formed so as to surround the entire outer periphery of the power generation region, a special operation such as adhesion is performed. It is possible to easily assemble the fuel cell by simply laminating each member without performing it.

[Application Example 8]
The fuel cell according to Application Example 7, wherein the top of the second gas seal convex portion is disposed at a position farther from the outer periphery of the power generation region than the top of the first gas seal convex portion. The first gas seal convex portion and the second gas seal convex portion are in contact with each other through the membrane-electrode assembly on the side surface near the top of each convex portion. According to the fuel cell described in Application Example 8, gas sealing can be performed not by contact by points (or lines) between the tops of the gas seal convex portions but by contact by a surface. Therefore, when assembling the fuel cell by laminating each component, it is not necessary to perform alignment as much as when the sealing performance is ensured at the top of the convex portion, and the operation of laminating is facilitated. Can do. Further, in such a fuel cell that ensures sealing performance by contact with the surface, even if a slight misalignment occurs between the gas separators, the fastening pressure is not easily lost at the contact portion between the gas seal convex portions. It is possible to secure a necessary fastening pressure and maintain high sealing performance.

[Application Example 9]
The fuel cell according to Application Example 8, wherein the first gas seal member is further spaced apart from the entire outer periphery of the power generation region than the second gas seal convex portion. The second gas seal convex portion and the third gas seal convex portion are in contact with each other on the side surface in the vicinity of the top of each convex portion. Fuel cell. According to the fuel cell of Application Example 9, the gas flow path is sealed by the contact portion between the first gas seal convex portion and the second gas seal convex portion, and the second gas seal convex portion and the third. Since it secures in two places of the contact part between these gas seal convex parts, the reliability of a gas seal can be improved.

  The present invention can be realized in various forms other than those described above. For example, the present invention can be realized in the form of a fluid sealing method in a fuel cell, a fuel cell separator, or the like.

1 is a schematic cross-sectional view illustrating a schematic configuration of a fuel cell 10. 3 is a plan view schematically showing a state of an anode facing separator 30. FIG. 3 is a plan view schematically showing a state of a cathode facing separator 31. FIG. 4 is a plan view showing the shape (planar arrangement) of linear convex portions and concave portions in the gas separator 30. FIG. 3 is a plan view showing the shape (planar arrangement) of linear convex portions and concave portions in a gas separator 31. FIG. It is explanatory drawing showing a mode that a fastening pressure is added to a linear convex part. 1 is a schematic cross-sectional view illustrating a schematic configuration of a fuel cell 10. 4 is a side view showing a state of the sealing plate 36. FIG. It is a cross-sectional schematic diagram showing a mode that the refrigerant side flow suppression part 42 is arrange | positioned. 4 is an explanatory view showing a state in which a refrigerant flows on a refrigerant flow path surface of a gas separator 30. FIG. 2 is a schematic cross-sectional view showing a configuration of a fuel cell 110. FIG. 2 is a schematic cross-sectional view illustrating a configuration of a fuel cell 210. FIG. 3 is a plan view illustrating a configuration of a gasket 234. FIG. 2 is a schematic cross-sectional view showing the configuration of a fuel cell 310. FIG. 6 is a plan view illustrating a configuration of a refrigerant flow path forming unit 325. FIG.

A. Overall configuration of the fuel cell 10:
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a fuel cell 10 according to a first embodiment of the present invention. The fuel cell 10 of the present embodiment is a polymer electrolyte fuel cell and has a stack structure in which a plurality of single cells 15 shown in FIG. 1 are stacked.

  The single cell 15 includes a membrane-electrode assembly (MEA) 20 including an electrolyte membrane and electrodes (anode and cathode) formed on both surfaces of the electrolyte membrane. Further, a pair of gas diffusion layers 21 and 22 sandwiching the MEA 20 from both sides, a pair of gas flow path forming portions 23 and 24 stacked so as to be in contact with the gas diffusion layers 21 and 22, 24 and a pair of gas separators 30 and 31 that are further stacked so as to be in contact with 24. Between the gas separator 30 and the MEA 20 is formed an in-cell fuel gas flow path through which a hydrogen-containing fuel gas flows. Between the gas separator 31 and the MEA 20, an oxidizing gas containing oxygen (this embodiment) Then, an in-cell oxidizing gas flow path through which air flows is formed. In the following description, the gas separator 30 is also referred to as an anode facing separator 30, and the gas separator 31 is also referred to as a cathode facing separator 31. Further, in the fuel cell 10 of the present embodiment in which a plurality of single cells 15 are stacked, a gas separator 30 provided in one single cell 15 and a gas separator provided in the other single cell 15 are disposed between adjacent single cells. The refrigerant flow path forming part 25 is arranged so as to contact both of the gas and the inter-cell refrigerant flow path.

  The electrolyte membrane is a proton conductive ion exchange membrane formed of a solid polymer material, for example, a fluorine-based resin, and exhibits good electrical conductivity in a wet state. The anode and the cathode include a catalyst (for example, platinum or a platinum alloy), and are formed by supporting these catalysts on a conductive carrier (for example, carbon particles). In order to form the cathode and the anode, for example, a carbon powder carrying a catalyst metal such as platinum is produced, and a paste is produced using the catalyst-carrying carbon and an electrolyte similar to the electrolyte constituting the electrolyte membrane. The prepared catalyst paste may be applied on the electrolyte membrane. The gas diffusion layers 21 and 22 can be formed of a conductive member having gas permeability, such as carbon paper or carbon cloth. The MEA 20 and the gas diffusion layers 21 and 22 are integrated by sandwiching the MEA 20 between the gas diffusion layers 21 and 22 and press-bonding them.

  The gas flow path forming portions 23 and 24 are conductive thin plate members formed of a metal porous body such as expanded metal or foam metal, a corrugated metal plate, or a carbon porous body. Yes, in this embodiment, an expanded metal made of titanium is used. Between the gas diffusion layer 21 and the gas separator 30, the space formed by the gas flow path forming portion 23 functions as the above-described in-cell fuel gas flow path together with the space formed in the gas diffusion layer 21. In addition, the space formed by the gas flow path forming unit 24 between the gas diffusion layer 22 and the gas separator 31 functions as the previously described in-cell oxidizing gas flow path together with the space formed in the gas diffusion layer 22. To do.

  The refrigerant flow path forming portion 25 is a conductive thin plate member formed of a metal porous body such as expanded metal or foam metal, a corrugated metal plate, or a carbon porous body. In the present embodiment, a corrugated plate member made of titanium is used. A space formed by the refrigerant flow path forming portion 25 between the gas separators 30 and 31 functions as the above-described inter-cell refrigerant flow path.

  The gas separators 30 and 31 are gas-impervious conductive members, for example, thin plate-like members formed of a dense carbon made of compressed carbon and gas-impermeable, baked carbon, or stainless steel. is there. In this embodiment, stainless steel is used, and the gas separators 30 and 31 are made thin by forming uneven shapes and holes, which will be described later, provided in the gas separators 30 and 31 by pressing or punching. It has become. The gas separators 30 and 31 are members constituting the wall surfaces of the in-cell fuel gas flow path, the in-cell oxidizing gas flow path, or the inter-cell refrigerant flow path, and the gas flow path forming portions 23 and 24 or the refrigerant flow. The contact portion with the path forming portion 25 is formed on a flat surface, and a predetermined uneven shape is formed on the other portion.

FIG. 2 is a plan view schematically showing the state of the anode facing separator 30. 2A shows a surface (gas flow channel surface) that forms the fuel gas flow channel in the cell, and FIG. 2B shows a surface (refrigerant flow channel surface) that forms the inter-cell refrigerant flow channel. FIG. 3 is a plan view schematically showing the state of the cathode facing separator 31. FIG. 3A represents a surface (gas flow channel surface) that forms the in-cell oxidizing gas flow channel, and FIG. 3B represents a surface (refrigerant flow channel surface) that forms the inter-cell refrigerant flow channel. The gas separators 30 and 31 are provided with a plurality of holes (holes 50 to 59) near the outer periphery thereof. Specifically, along one side of gas separators 30 and 31 (side a shown in FIGS. 2A and 3A), holes 50 to 50 are holes having the direction of side a as the longitudinal direction. 52 is formed, and holes 53 to 55 which are holes having the direction of the side b as the longitudinal direction along the side (side b shown in FIGS. 2A and 3A) facing the side a. Is formed. Further, along the other sides of the gas separators 30 and 31 (side c shown in FIGS. 2A and 3A), the holes 56 and 57 are holes having the direction of the side c as the longitudinal direction. A hole 58, which is a hole whose longitudinal direction is the direction of the side d, along the side (side d shown in FIG. 2A and FIG. 3A) facing the side c. 59 is formed. When a fuel cell is assembled by laminating a plurality of single cells 15, holes provided at corresponding positions of the gas separators overlap each other and penetrate the inside of the fuel cell to the gas separator (hereinafter referred to as the stacking direction). Forming a fluid flow path. Specifically, the holes 50 to 52 form an oxidizing gas supply manifold that supplies the oxidizing gas to the in-cell oxidizing gas flow path (represented as “Air in” in FIGS. 2 and 3). Then, an oxidizing gas discharge manifold is formed through which oxidizing gas is discharged from the oxidizing gas channel in the cell (referred to as Air out in FIGS. 2 and 3). The hole 56 forms a fuel gas discharge manifold through which the fuel gas is discharged from the in-cell fuel gas flow path (represented as H ₂ out in FIGS. 2 and 3), and the hole 59 is the in-cell fuel gas flow A fuel gas supply manifold for supplying fuel gas to the passage is formed (indicated as H ₂ in in FIGS. 2 and 3). The hole 57 forms a refrigerant supply manifold that supplies the refrigerant to the inter-cell refrigerant flow path (referred to as CLT in in FIGS. 2 and 3), and the hole 58 discharges the refrigerant from the inter-cell refrigerant flow path. The refrigerant discharge manifold is formed (denoted as CLT out in FIGS. 2 and 3).

  In FIG. 1 and FIG. 2A, a region where an electrochemical reaction proceeds in the MEA 20, specifically, a region where the MEA 20 and the gas diffusion layers 21 and 22 are in contact with each other and a region overlapping in the stacking direction are defined as a power generation region. As shown. As shown in FIG. 2A, the power generation region is formed in a square shape. Further, as shown in FIG. 1, in this embodiment, the gas flow path forming portions 23 and 24 and the refrigerant flow path forming portion 25 are also formed in a shape overlapping the power generation region.

B. Configuration related to seal:
As shown in FIGS. 1 to 3, the fuel cell 10 further includes gaskets 32, 34, 35 and sealing plates 33, 36 on the gas separators 30, 31. In the fuel cell 10, the in-cell fuel gas channel, the in-cell oxidizing gas channel, and the inter-cell refrigerant channel are sealed by providing the gasket and the sealing plate with a convex portion having a linear top. Yes. Both the gasket and the sealing plate are members for sealing the flow path, but the sealing plate seals the in-cell gas flow path (in-cell fuel gas flow path and in-cell oxidizing gas flow path) as a whole. However, the gas flow between the in-cell gas flow path and the gas manifold is enabled at a specific location. The structure of the sealing plate will be described in detail later. FIG. 1 is a cross section along line 1-1 in FIG. 2 and shows the state of the hole 51 and the vicinity thereof.

  4 and 5 show the shape of the linear protrusions formed on the gaskets and sealing plates arranged on the gas separators 30 and 31 (planar arrangement of the top of the head) and the gas separators 30 and 31. It is a top view showing the made recessed part. Specifically, FIG. 4A shows the shape of the linear protrusions formed on the gasket and sealing plate disposed on the gas flow path surface of the gas separator 30. FIG. 4B shows the shape of linear protrusions formed on the gasket disposed on the refrigerant flow path surface of the gas separator 30 and the recesses formed on the refrigerant flow path surface of the gas separator 30. FIG. 5A shows the shape of linear protrusions formed on the gasket and sealing plate disposed on the gas flow path surface of the gas separator 31. FIG. 5B shows the shape of the recess formed in the refrigerant flow path surface of the gas separator 31. 4 and 5, only the position of the sealing plate is indicated by a broken line in the gasket and the sealing plate shown in FIGS. 2 and 3. In the fuel cell 10 of the present embodiment, the gas separators 30 and 31 are formed with uneven shapes, and the linear protrusions of the gasket are placed on the formed separator protrusions so that the gas flow paths in the cell The seal is improved. Hereinafter, as an explanation of the structure related to the seal, first, the arrangement of the gasket and the sealing plate and the arrangement of the linear protrusions formed on the gasket and the sealing plate will be described in detail.

  On the gas flow path surface side of the gas separator 30, the gasket 32 and the sealing plate 33 are disposed at a position closer to the center than the area where the holes 50 to 59 are provided and closer to the outer periphery than the power generation area. (See FIG. 2A). The gasket 32 and the sealing plate 33 constitute a first gas flow path sealing member as a whole, and the first linear convex portion 60 and the third convex portion which are convex portions for sealing the in-cell fuel gas flow passage. A linear protrusion 62 is formed (see FIG. 1). The first linear convex portion 60 and the third linear convex portion 62 are formed in a shape that surrounds the entire outer periphery of the power generation region, and the third linear convex portion 62 is more than the first linear convex portion 60. It is formed closer to the outer periphery (see FIG. 4A).

  A gasket 35 and a sealing plate 36 are disposed on the gas flow path surface side of the gas separator 31 (see FIG. 3A). A part of the gasket 35 and the sealing plate 36 are disposed at a position closer to the center than the area where the holes 50 to 59 are provided and closer to the outer periphery than the power generation area. A part of these gaskets 35 and the sealing plate 36 constitute a second gas flow path sealing member as a whole, and a second linear convex part which is a convex part for sealing the in-cell oxidizing gas flow path. 61 is formed (see FIG. 1). This 2nd linear convex part 61 is formed in the shape surrounding the whole outer periphery of an electric power generation area | region (refer FIG. 5 (A)). The 2nd linear convex part 61 is provided between the position which overlaps with the 1st linear convex part 60 in the lamination direction, and the position which overlaps with the 3rd linear convex part 62 in the lamination direction, and via MEA20 The first linear protrusion 60 and the third linear protrusion 62 come into contact (see FIG. 1). In the MEA 20, it is not necessary to form an electrode closer to the outer periphery than a portion sandwiched between the second linear convex portion 61 and the first linear convex portion 60. As described above, the second linear convex portion 61, the first linear convex portion 60, and the third linear convex portion 62 come into contact with each other, thereby sealing the in-cell fuel gas channel and the in-cell oxidizing gas channel. Is done.

  On the gas flow path surface side of the gas separator 31, a fourth linear convex portion 63 is further formed in the gasket 35 in addition to the second linear convex portion 61 (see FIG. 1). This 4th linear convex part 63 is formed in the position surrounding hole parts 50-59 other than the position where the 2nd linear convex part 61 was formed (refer FIG. 5 (A)). The 4th linear convex part 63 is contact | abutted on the surface of the gas separator 30 arrange | positioned facing the gas separator 31 within the single cell 15 (refer FIG. 1). Thereby, gas or a refrigerant | coolant is sealed in the outer periphery of the holes 50-59. In addition, in the gas flow path surface of the gas separator 30 shown to FIG. 2 (A) and FIG. 4 (A), the location where the top part of the 4th linear convex part 63 contact | abuts is a 2 dotted chain line as the sealing line SL. Show.

  In addition, a gasket 34 having a fifth linear protrusion 64 formed thereon is disposed on the refrigerant flow path surface of the gas separator 30 (see FIG. 1). The gasket 34 and the 5th linear convex part 64 are arrange | positioned in the position surrounding a power generation area | region, and the position surrounding the hole parts 50-59 (refer FIG. 2 (B) and FIG. 4 (B)). The 5th linear convex part 64 contact | abuts the surface of the gas separator 31 with which the single cell 15 which adjoins through the refrigerant flow path formation part 25 (refer FIG. 1). As a result, the inter-cell refrigerant flow path is sealed, and gas or refrigerant is sealed at the outer periphery of the holes 50 to 59. However, the fifth linear convex portion 64 is not formed so as to surround the entire circumference of the power generation region, but is along the longitudinal sides of the hole portion 57 and the hole portion 58 in the entire circumference of the power generation region. There is no location. That is, it is not provided in the region along the hole 57 that is the inflow portion of the refrigerant to the inter-cell refrigerant flow path and the region along the hole 58 that is the outflow portion of the refrigerant from the inter-cell refrigerant flow path. As a result, the inter-cell refrigerant flow path and the refrigerant manifold can communicate with each other. In addition, in the refrigerant | coolant flow path surface of the gas separator 31 shown to FIG. 3 (B) and FIG. 5 (B), the location which the top part of the 5th linear convex part 64 contact | abuts is a 2 dotted chain line as the sealing line SL. Show.

  In the fuel cell 10 in which the single cells 15 are laminated, the linear protrusions formed on the gaskets and sealing plates arranged on the gas separators 30 and 31 as described above are arranged at positions where they overlap in the lamination direction. Is done. In the fuel cell 10, as described later, a fastening pressure is applied in the stacking direction, and a sealing force is realized by generating a reaction force from the gas separator or the sealing plate to the gas separator against the fastening pressure. . Here, in the fuel cell 10, the position of the refrigerant seal that overlaps in the stacking direction (the position at which the fifth linear protrusion 64 abuts the gas separator 31) is the position of the gas seal that overlaps in the stacking direction (first linear shape). The convex portion 60 and the second linear convex portion 61 are provided closer to the outer periphery of the gas separator than the position where the convex portion 60 and the second linear convex portion 61 are in contact via the MEA 20. Therefore, the entire region where the gas flows and an electrochemical reaction can occur can be efficiently cooled by the refrigerant. Further, the third linear convex portion 62 and the fifth linear convex portion 64 are provided at positions overlapping each other on both surfaces of the gas separator 30. Thereby, the 3rd linear convex part 62 and the 5th linear convex part 64 mutually support in the fuel cell 10 whole, and can improve the sealing performance in each linear convex part.

  In the gas separators 30 and 31, a convex portion that is convex in the same direction as the linear convex portion is provided in a part of the position overlapping the linear convex portion included in the gasket as a shape that reverses the front and back. On the convex part formed in such gas separators 30 and 31, the linear convex part of the gasket is formed in a shape along the convex part. Specifically, the separator convex part 70 is provided in the position which overlaps with the 1st linear convex part 60 formed in the gasket 32 in the gas flow path surface of the gas separator 30 (refer FIG. 1). The separator convex portion 70 is not provided at a position overlapping the first linear convex portion 60 formed on the sealing plate 33. In FIG. 4A, the portion formed on the separator convex portion 70 (the portion formed on the gasket 32) in the first linear convex portion 60 is represented by a thicker line, and the separator convex portion 70 is formed. A portion formed on a flat surface that is not formed (portion formed on the sealing plate 33) is represented by a thinner line. In addition, although a part of 3rd linear convex part 62 is formed on the linear recessed part so that it may mention later, in FIG. 4 (A), about 3rd linear convex part 62, it is a thin line | wire. It is represented by

  Similarly, the separator convex part 71 is provided in the position which overlaps with the 2nd linear convex part 61 formed in the gasket 35 in the gas flow path surface of the gas separator 31 (refer FIG. 7 mentioned later). The separator convex portion 71 is not provided at a position overlapping the second linear convex portion 61 formed on the sealing plate 36. In FIG. 5A, the portion formed on the separator convex portion 71 (the portion formed on the gasket 35) in the second linear convex portion 61 is represented by a thicker line, and the separator convex portion 71 is formed. A portion formed on a flat surface that is not formed (portion formed on the sealing plate 36) is represented by a thinner line. In addition, since the 4th linear convex part 63 is formed on the flat surface, it represents with a thinner line.

  Similarly, on the refrigerant flow path surface of the gas separator 30, the separator convex portion 74 is located at a position overlapping with a portion provided along the outer periphery of the power generation region in the fifth linear convex portion 64 formed on the gasket 34. Provided (see FIG. 1). In FIG. 4 (B), the part formed on the separator convex part 74 among the 5th linear convex parts 64 is represented by a thicker line, and is formed on the flat surface in which the separator convex part 74 is not formed. The part that is shown is represented by a thinner line.

  Thus, by providing the separator convex portions 70, 71, 74 on the respective gas separators 30, 31, and arranging the gasket so that the linear convex portions cover the convex portions 70, 71, 74, in this embodiment, The sealing performance in the in-cell gas flow path and the inter-cell refrigerant flow path is improved. FIG. 6 is an explanatory diagram showing a state in which a fastening pressure is applied to a linear protrusion formed on the gasket inside the fuel cell. FIG. 6A is an explanatory view showing a state in which gaskets 32, 34, and 35 having linear convex portions are arranged on separator convex portions 70, 71, and 74, and FIG. It is explanatory drawing showing a mode that the gasket was arrange | positioned on the flat gas separator surface which does not have a part. In FIG. 6, the fastening pressure applied to the contact portion between the gasket and the gas separator is indicated by a white arrow, and the reaction force generated on the gas separator in the gasket against the fastening pressure is indicated by a hatched arrow. Is shown. As shown in FIG. 6 (A), when the gasket is disposed on the separator convex portion, the thickness of the gasket is suppressed in the vicinity of the top portion of the linear convex portion, so any of the gaskets that come into contact with the gasket A strong reaction force is generated in the gasket also between the gas separator and the sealing performance in the gas flow path in the cell can be sufficiently ensured. On the other hand, as shown in FIG. 6B, when the gasket is arranged on a flat surface where the separator convex portion is not formed, the thickness of the gasket is particularly thick at the position near the top of the linear convex portion. Therefore, the reaction force generated from the gasket to the gas separator is weakened on the surface opposite to the linear convex portion.

  In addition, as described above, the convex portions 70 and 71 that are convex on the gas flow path surface side provided in the gas separators 30 and 31 have a shape that reverses the front and back as described above, and therefore, a concave portion is formed on the back surface of each gas separator. Has been. In FIG. 4 (B), the position of the recessed part 80 as a back surface shape of the separator convex part 70 is shown with the dashed-dotted line. Further, in FIG. 5B, a concave portion 81 as a back surface shape of the separator convex portion 71 is indicated by a one-dot chain line. In the gas separator 30, a concave portion is formed on the gas flow path surface side as a back side shape of the separator convex portion 74 that is convex on the refrigerant flow channel side. A third portion formed on the gasket 32 is formed on the concave portion. Since the linear convex part 62 is arrange | positioned, this recessed part is not represented in FIG. 4 (A).

As described above, the sealing plates 33 and 36 are members that seal the in-cell gas flow path and communicate the in-cell gas flow path with the gas separator corresponding to the in-cell gas flow path. The sealing plate 33 communicates the in-cell fuel gas flow path with the fuel gas manifold (hole 56 or 59). Moreover, the sealing plate 36 makes the in-cell oxidizing gas flow path and the oxidizing gas manifold (holes 50 to 55) communicate with each other. FIG. 7 is a schematic cross-sectional view showing a state in which the sealing plate 33 is arranged in the same manner as FIG. 1 showing the sealing plate 36. FIG. 7 shows the state of the hole 59 and the vicinity thereof, and the position of the cross section shown in FIG. 7 is shown in FIG. 2A as a 7-7 cross section. 1 and FIG. 7, the white arrows indicate that the oxidizing gas (O _{2 in} FIG. 1) or the fuel gas (H _{2 in} FIG. 7) flowing through the gas manifold flows into the in-cell gas flow path. ing.

  A plurality of communication holes 38 are formed in the sealing plates 33 and 36 so that the in-cell gas flow path and the manifold can communicate with each other. FIG. 8 is a side view showing the state of the sealing plate 36 shown in FIG. 1, and shows the state when the sealing plate 36 is viewed from the same direction as the arrow showing the flow direction of the oxidizing gas in FIG. The sealing plate 36 shown in FIG. 8 is formed with a plurality of parallel communication holes 38 for communicating the in-cell oxidizing gas flow path with the holes 51. Similarly, a plurality of communication holes are formed in the other sealing plates 36 and 33 in parallel with the gas flow direction between the gas manifold and the in-cell gas flow path.

  Here, the sealing plates 33 and 36 are constituted by members having such rigidity that the communication holes 38 are not crushed by the fastening pressure when the members constituting the fuel cell 10 are stacked and fastened together. Specifically, the sealing plates 33 and 36 can be made of, for example, a resin such as plastic that is sufficiently stable at the operating temperature of the fuel cell 10 or a thin plate-like metal coated with a resin. When using a resin material, the sealing plates 33 and 36 may be formed by injection molding, for example. The communication hole 38 can be formed, for example, by cutting after the molding. In the gas separators 30, 31, the separator projections 70, 71 are not provided at the locations where the sealing plates 33, 36 are disposed, so these are formed in the communication holes 38 formed in the sealing plates 33, 36. The gas flow is not suppressed by the separator protrusion.

  The gaskets 32, 34, and 35 are configured by members that have elasticity that generates a reaction force for sealing between adjacent members when the fuel cell 10 is fastened, and that are sufficiently stable at the operating temperature of the fuel cell 10. do it. As a material for such a gasket, rubber or thermoplastic elastomer can be used. Examples of the rubber include silicon rubber, polyisobutylene (PIB, butyl rubber), acrylic rubber, natural rubber, fluorine rubber, ethylene / propylene rubber such as EPM and EPDM, nitrile butadiene rubber (NBR), urethane rubber, and chloro. Sulfonated polyethylene (CSN), chlorinated polyethylene (CPE), polysulfide rubber, and epichlorohydrin rubber (CO, CEO) can be used. As the thermoplastic elastomer, for example, a styrene elastomer or a fluorine elastomer can be used. The gaskets 32, 34, and 35 may also be formed by injection molding, for example.

  The sealing plates 33 and 36 and the gaskets 32, 34, and 35 thus manufactured may be fixed at predetermined positions on the gas separators 30 and 31 prior to assembly of the fuel cell 10. In the gas separators 30 and 31, a predetermined uneven shape is formed at a place where each gasket and the sealing plate are arranged. By fitting the gasket and the sealing plate into the uneven shape of the gas separator, the gasket In addition, the sealing plate can be fixed. Or in order to improve the reliability at the time of fixing a gasket and a sealing plate to a gas separator, it is good also as fixing using an adhesive agent. In any case, the gasket and the sealing plate and the gas separator have the corresponding concavo-convex shape, so that they can be easily aligned and fixed together. Further, the gasket and the sealing plate may be formed integrally with the gas separators 30 and 31, instead of being formed separately. That is, the gas separators 30 and 31 are arranged in a mold having a shape corresponding to the gasket or the sealing plate, and injection molding is performed to form the gasket or the sealing plate. , 31 can be integrally formed.

C. Configuration for suppressing side flow of refrigerant:
In the fuel cell 10, as described above, in the gas separators 30 and 31, the separator convex portions 70 and 71 are provided at positions overlapping the linear convex portions provided on the gasket, and the refrigerant of the gas separators 30 and 31 is provided. On the flow path surface side, concave portions 80 and 81 are formed as the inverted shape of the separator convex portion. Here, in the inter-cell refrigerant flow path formed between adjacent single cells 15, a gap is formed between the outer periphery of the refrigerant flow path forming portion 25 and the gasket 34. The flow path resistance when the refrigerant flows through such a gap is generally smaller than the flow path resistance when the refrigerant flows through the pores in the refrigerant flow path forming portion 25. In particular, when the recesses 80 and 81 are formed in the gap between the outer periphery of the refrigerant flow path forming portion 25 and the gasket 34, the flow path cross-sectional area of the refrigerant increases in the gap with a small flow path resistance. , It becomes easier for the refrigerant to flow. As described above, when the flow rate of the refrigerant flowing in the gap formed in the outer periphery of the refrigerant flow path forming portion 25 (hereinafter, the refrigerant flowing in the outer periphery of the refrigerant flow path forming portion 25 is referred to as the side flow of the refrigerant) is increased. The flow rate of the refrigerant flowing through the refrigerant flow path forming portion 25 is relatively reduced. In the present embodiment, in order to suppress such a side flow of the refrigerant, a refrigerant side flow suppression unit is provided in the outer periphery of the refrigerant flow path forming unit 25.

  On the gas separator 30, a refrigerant side flow suppressing portion 40, which is an independent member, is disposed in a concave portion 80 that is a back side structure of the separator convex portion 70 that overlaps the first linear convex portion 60 (FIG. 1 and FIG. 1). 4 (B)). The recess 80 is formed between the outer periphery of the refrigerant flow path forming portion 25 and the gasket 34 so as to extend along the sides in the longitudinal direction of the gas separator 30 (side a and side b). The flow suppression unit 40 is disposed in the vicinity of the center of the side in the longitudinal direction. As shown in FIG. 1, the refrigerant side flow suppressing portion 40 is disposed by fitting a tip portion formed in a shape along the inner wall surface shape of the recess 80 into the recess 80. The other end of the refrigerant side flow suppression unit 40 is in contact with the gas separator 31 facing the gas separator 30, but may not be in contact. However, when the other end of the refrigerant side flow suppressing unit 40 is in contact with the gas separator 31, the height of the refrigerant side flow suppressing unit 40 is determined by the fastening pressure applied to the refrigerant flow path forming unit 25 when the fuel cell 10 is fastened. It is desirable that the height not be reduced. Thereby, the increase in the contact resistance resulting from the refrigerant side flow suppression unit 40 can be suppressed. Moreover, it is desirable that the refrigerant side flow suppression unit 40 does not generate a reaction force larger than that of the gasket 34 at the time of fastening. Thereby, the fall of the sealing performance in the refrigerant | coolant flow path between cells resulting from providing the refrigerant | coolant side flow suppression part 40 can be suppressed. Such a refrigerant side flow suppression unit 40 can be formed of a member made of various materials that are stable at the operating temperature of the fuel cell 10, such as a metal plate or a resin plate. By making the refrigerant side flow suppressing unit 40 an independent member separate from other members constituting the fuel cell 10, the degree of freedom in selecting the constituent material of the refrigerant side flow suppressing unit 40 can be increased. For example, when an elastic member made of rubber, thermoplastic elastomer, or the like is used, the operation of fitting and holding the refrigerant side flow suppressing portion 40 at a predetermined position on the gas separator 30 is facilitated. Further, when a resin member is used, an increase in the weight of the fuel cell 10 due to the refrigerant side flow suppression unit 40 can be suppressed. Furthermore, by configuring the refrigerant side flow suppressing unit 40 with an independent member, the refrigerant flow path forming unit 25 is stacked after the refrigerant side flow suppressing unit 40 is disposed on the gas separator 30 when the fuel cell 10 is assembled. In that case, the refrigerant flow path forming part 25 may be arranged at a position closer to the center of the gas separator 30 than the position where the refrigerant side flow suppressing part 40 is arranged. Therefore, the effect that the alignment at the time of arrange | positioning the refrigerant | coolant flow path formation part 25 becomes easy is acquired.

  Similarly, on the gas separator 31, the refrigerant side flow suppressing portion 42, which is an independent member, is disposed in the concave portion 81 that is the back side structure of the separator convex portion 71 provided at a position overlapping the second linear convex portion 61. ing. FIG. 9 is a cross-sectional view taken along the line 9-9 in FIG. 3B corresponding to the position where the refrigerant side flow suppressing portion 42 is disposed, and shows a state in the vicinity of the region between the hole 50 and the hole 51. It is a cross-sectional schematic diagram. Here, although the refrigerant side flow suppression unit 40 is not provided in the 9-9 cross section, the position corresponding to the refrigerant side flow suppression unit 40 is indicated by a broken line in FIG. 9. 3B and 5B show a planar arrangement of the refrigerant side flow suppressing portion 42. A recess 81 is formed in the gas separator 31 in the vicinity of the region between the holes 50 and 51, the holes 51 and 52, the holes 53 and 54, and the holes 54 and 55 (FIG. 5B). As shown in FIG. 9, the refrigerant side flow suppressing portion 42 is disposed so as to be fitted into the concave portion 81. 9 has a shape that does not contact the gas separator 30, but may have a shape that contacts the gas separator 30. In addition, the refrigerant side flow suppressing portion 42 can be formed of a member made of various materials in the same manner as the refrigerant side flow suppressing portion 40 described above. However, if it is formed of an elastic member, the refrigerant side flow suppressing portion 42 is fitted into the recess 81. The operation of holding with becomes easy. In addition, you may adhere | attach the refrigerant | coolant side flow suppression parts 40 and 42 on the gas separators 30 and 31 using an adhesive agent.

  When assembling the fuel cell 10, the gaskets 32, 34, 35 and the sealing plates 33, 36 are fixed to predetermined positions on the gas separators 30, 31, and the refrigerant side flow suppression units 40, 42 are fitted. Include. Then, such gas separators 30 and 31, MEA 20, gas diffusion layers 21 and 22, gas flow path forming portions 23 and 24, and refrigerant flow path forming portion 25 are sequentially stacked. Thus, when producing the laminated body of the single cell 15, a current collecting plate provided with an output terminal, an insulating plate, and an end plate are arrange | positioned at each of the both ends. Then, the entire fuel cell 10 is fastened while applying a predetermined pressing force from both sides of the end plate, and the fuel cell 10 is completed.

  According to the fuel cell 10 of the present embodiment configured as described above, the gaskets 32 and 35 or the sealing are provided so as to overlap the separator convex portions 70 and 71 provided on the gas flow path surface side of the gas separators 30 and 31. Since the linear protrusions 60 and 61 provided on the plates 33 and 36 are arranged, the sealing performance of the linear protrusions 60 and 61 can be improved. In the fuel cell 10, the position of the refrigerant seal that overlaps in the stacking direction is provided closer to the outer periphery of the gas separator than the position of the gas seal that overlaps in the stacking direction. The entire possible area can be efficiently cooled. In such a fuel cell 10, in the present embodiment, the refrigerant side flow suppressing portions 40, 42 are provided in the concave portions 80, 81 that are the back side structures of the separator convex portions 70, 71 on the refrigerant flow path surface side of the gas separators 30, 31. Since it is provided, it is possible to suppress an increase in the side flow of the refrigerant due to the provision of the separator convex portions 70 and 71 in order to improve the sealing performance. By suppressing the side flow of the refrigerant, the flow rate of the refrigerant flowing in the refrigerant flow path forming unit 25 can be relatively increased, so that the cooling efficiency of the fuel cell 10 by the refrigerant can be improved.

  Here, in the inter-cell refrigerant flow path, the refrigerant flows from the hole 57 constituting the refrigerant supply manifold to the hole 58 constituting the refrigerant discharge manifold. Therefore, the side flow in the inter-cell refrigerant flow path includes a flow along the holes 56, 50, 51, 52 and a flow along the holes 53, 54, 55, 59. FIG. 10 is an explanatory diagram showing the flow of the refrigerant on the refrigerant flow path surface of the gas separator 30. In FIG. 10, the state of the side flow of the refrigerant is indicated by broken-line arrows. Further, in FIG. 10, the refrigerant flowing in the refrigerant flow path forming portion 25 is represented by a white arrow from the hole portion 57 toward the hole portion 58.

  Of the pressure loss when the refrigerant flows through the inter-cell refrigerant flow path, ΔP1 is the pressure loss when the refrigerant flows through the refrigerant flow path forming portion 25, and the refrigerant flows through the gap formed in the outer periphery of the refrigerant flow path forming portion 25. Assuming that the pressure loss during the operation is ΔP2 (see FIG. 10), it is necessary to satisfy “ΔP1 <ΔP2” in order to secure the flow rate of the refrigerant that passes through the refrigerant flow path forming unit 25 (flows through the power generation region). . In the present embodiment, the separator convex portions 70 and 71 are provided in order to improve the sealing performance, so that the cross-sectional area of the refrigerant flow path becomes large in the concave portions 80 and 81 as the back side structure. By providing the refrigerant side flow suppressing portions 40 and 42 in the concave portions 80 and 81, it is possible to suppress a decrease in the pressure loss ΔP2 when the refrigerant flows side by side. The shape of the refrigerant side flow suppressing portions 40 and 42 may be any shape that can realize “ΔP1 <ΔP2”, and thereby, an effect of ensuring the flow rate of the refrigerant flowing in the refrigerant flow path forming portion 25 can be obtained.

  Among the recesses provided on the refrigerant flow path surface side of the gas separators 30 and 31, in particular, the recess 80 is provided continuously along the side (side a or side b) in the longitudinal direction of the gas separator 30, The action of reducing the flow path resistance and increasing the side flow of the refrigerant is strong. Therefore, the refrigerant side flow suppressing portion 40 provided in the portion extending in the longitudinal direction in the recess 80 is particularly effective in suppressing the side flow of the refrigerant. However, the recesses 81 provided apart from each other in the vicinity of the longitudinal side of the gas separator 31 also have an effect of facilitating the side flow by partially increasing the cross-sectional area of the refrigerant flow path. Therefore, a high effect of suppressing the side flow of the refrigerant can also be obtained by the refrigerant side flow suppression unit 42 provided in the recess 81.

  In addition, by providing the refrigerant side flow suppression units 40 and 42, the refrigerant flow rate in the entire power generation region can be made uniform, and the cooling efficiency can be made uniform in the power generation region, thereby improving the performance of the fuel cell. Is obtained. That is, the refrigerant side flow restraint portions 40, 42 are provided only in a part of the recesses 80, 81 in the gap formed between the outer periphery of the refrigerant flow path forming member and the gasket 34. It can spread easily into the gap in the outer peripheral portion where the flow suppressing portions 40 and 42 are not provided. Since the refrigerant side flow suppressing portions 40, 42 are provided in the gap, the refrigerant that has spread into the gap then flows into the refrigerant flow path forming portion 25. As described above, since it becomes easy to take a path for the refrigerant to once flow into the gap in the outer peripheral portion and then flow into the refrigerant flow path forming portion 25, the refrigerant flow rate in the entire power generation region can be made uniform. For example, depending on the positional relationship of the refrigerant manifold, the refrigerant flow rate is nonuniform in the power generation region. In particular, in the present embodiment, since the two refrigerant manifolds are in the vicinity of the diagonal, when the refrigerant side flow suppression portion is not provided, when the refrigerant flows from the hole portion 57 to the hole portion 58, the power generation region In the vicinity of the remaining corner of the refrigerant, the refrigerant flow rate becomes relatively small. In such an outer peripheral space of the refrigerant flow path forming portion 25 of the fuel cell 10, recesses 80 and 81 for facilitating the inflow of the refrigerant are provided, and the refrigerant side flow is suppressed in the middle of the gap formed in the longitudinal direction of the separator. By providing the portions 40 and 42, the refrigerant flow rate in the vicinity of the remaining corner portion can be relatively increased in the refrigerant side flow suppressing portion 40.

  In order to suppress the side flow of the refrigerant caused by the gap around the refrigerant flow path forming portion 25 when the refrigerant flow path forming portion 25 is manufactured, the refrigerant flow path forming portion 25 is generally manufactured with high accuracy, It is necessary to make the gap between the outer periphery of the flow path forming portion 25 and the inner periphery of the gasket 34 as small as possible. However, in this embodiment, since the side flow is suppressed by the refrigerant side flow suppression units 40 and 42, it is not necessary to increase the manufacturing accuracy of the refrigerant flow path forming unit 25, and the manufacturing cost can be reduced.

  Moreover, according to the fuel cell 10 of the present embodiment, in addition to the effects relating to the refrigerant side flow suppression units 40 and 42 described above, the following various effects are further exhibited. According to the fuel cell 10 of the present embodiment, the sealing performance to be ensured in the operation of stacking the fuel cells can be realized only by physical sealing. Specifically, if a gasket and a sealing plate on which linear convex portions for sealing are formed are fixed to predetermined positions of the gas separators 30 and 31 in advance, such a gas separator can be used as an MEA 20 or the like. The flow path can be sealed only by overlapping with other members in a predetermined order and finally fastening the whole. Here, the connection between each gas manifold and the gas flow path in the cell is ensured by a communication hole 38 provided in the sealing plate, and the first to third linear protrusions are continuously formed as a whole in the power generation region. It is formed in a shape that surrounds the entire circumference. Thus, in order to ensure the gas sealing performance by sandwiching the MEA 20 with the linear projections that surround the entire circumference of the power generation region, it is not necessary to perform a special operation such as adhesion when laminating each member. Assembly can be performed easily. In particular, when an adhesive is not used when the gasket and the sealing plate are fixed to the gas separator, it is not necessary to use an adhesive for the entire fuel cell, and the sealing performance due to a decrease in adhesiveness due to deterioration of the adhesive. Can be suppressed.

  Further, according to the fuel cell 10, the seal of the gas flow path in the cell is formed by the contact portion between the first linear convex portion 60 and the second linear convex portion 61, and the second linear convex portion 61 and the third. The reliability of the gas seal can be enhanced by using a double seal that is secured at two locations in contact with the linear protrusion 62. In the fuel cell 10 shown in FIG. 1, the MEA 20 is sandwiched between the second linear convex portion 61 and the first linear convex portion 60, and the second linear convex portion 61 and the third linear convex portion 62. However, a different configuration may be used. Although sandwiched between the second linear convex portion 61 and the first linear convex portion 60, it may not be sandwiched between the second linear convex portion 61 and the third linear convex portion 62. Even if the MEA 20 is not sandwiched, the second linear convex portion 61 and the third linear convex portion 62 are further in contact with each other, so that an effect of improving the reliability of the gas seal can be obtained by using a double seal. Furthermore, in the present embodiment, the contact portion between the linear convex portions for such a seal is provided on the side surface in the vicinity of the top portion of each linear convex portion, not the contact by the point (or line) at the top portion, Contact with the surface. For this reason, when laminating gas separators with gaskets and sealing plates fixed, it is not necessary to perform alignment as much as when sealing performance is secured at the top of the linear convex part, and laminating operation is easy. Can be Further, in the fuel cell 10 that secures the sealing performance by the contact with the surface as described above, even if a slight misalignment occurs between the gas separators during use of the fuel cell 10, Since the fastening pressure is not easily lost, it is possible to secure the necessary fastening pressure and maintain high sealing performance.

  In the first embodiment, the refrigerant side flow suppression unit 40 is provided in the recess 80 and the refrigerant side flow suppression unit 42 is provided in the recess 81, but a different configuration may be used. For example, only one of the refrigerant side flow suppression units 40 and 42 may be provided. Or when providing the refrigerant | coolant side flow suppression part 42, as providing only any one of the two refrigerant side flow suppression parts 42 located in a line along the side (side a or side b) of the longitudinal direction of a separator. Also good. In order to suppress the side flow along the side a or the side b, at least one refrigerant side flow suppression unit may be provided for each side. Further, the top portions of the refrigerant side flow suppressing portions 40 and 42 may not have a shape along (in contact with) the inner wall surfaces of the recesses 80 and 81 but may have a shape in which a gap is formed between the inner wall surfaces. If the refrigerant side flow restraint portions 40, 42 can be fitted and held in the recesses 80, 81, an effect of facilitating the operation of stacking the separators and assembling the fuel cell can be obtained. Regardless of the configuration, by providing the refrigerant side flow suppressing part, the pressure loss when the refrigerant flows in the refrigerant flow path forming part 25 is larger than the gap formed in the outer periphery of the refrigerant flow path forming part 25 than ΔP1. If ΔP2 can be increased in the pressure loss when the refrigerant flows sideways, the same effect as in the first embodiment can be obtained.

D. Second embodiment:
In the fuel cell 10, the refrigerant side flow suppression units 40 and 42, which are separate from the gas separator, are disposed in the gap formed between the gas separators 30 and 31 through which the refrigerant flows. Below, the Example provided with the refrigerant | coolant side flow suppression part of a different structure is described sequentially.

  FIG. 11 is a schematic cross-sectional view showing the configuration of the fuel cell 110 of the second embodiment. The configuration of the fuel cell 110 is the same as that of the fuel cell 10 except for the portion related to the refrigerant side flow suppression unit, and portions common to the fuel cell 10 are denoted by the same reference numerals and detailed description thereof is omitted. The fuel cell 110 constitutes a refrigerant side flow suppression portion by a part of one of the adjacent gas separators, and includes a gas separator 131 instead of the gas separator 31. The gas separator 131 is formed at the same position as the position where the refrigerant side flow suppressing portion 40 is disposed in the fuel cell 10 in a shape that is convex on the refrigerant flow path surface side and reverses upside down. A refrigerant side flow restraining convex portion 140 having a shape along the inner wall surface is formed.

  Also in the fuel cell 110 configured as described above, the refrigerant side flow suppressing convex portion 140 is provided, and the outer periphery of the refrigerant flow path forming portion 25 is more than the pressure loss ΔP1 when the refrigerant flows in the refrigerant flow path forming portion 25. The same effect as that of the first embodiment can be obtained by increasing the pressure loss ΔP2 when the refrigerant flows sideways through the gap formed in the first embodiment. At this time, the refrigerant side flow suppression convex portion 140 does not have to be formed so that the top of the refrigerant abuts against the inner wall surface of the concave portion 80, and if the pressure loss when the refrigerant flows side by side can be sufficiently increased, The height of the convex portion may be lower.

  In addition, according to the fuel cell 110, the refrigerant side flow suppressing portion is integrally formed with the gas separator as the refrigerant side flow suppressing convex portion, so that the number of parts can be suppressed as compared with the first embodiment. Furthermore, when assembling the fuel cell 110, the refrigerant side flow restraining convex portion 140 of the gas separator 131 only needs to be fitted into the concave portion 80 of the gas separator 30, so that the alignment between the gas separator 131 and the gas separator 30 is easy. Can be

  In FIG. 11, only the refrigerant side flow suppression convex portion 140 corresponding to the refrigerant side flow suppression portion 40 is provided, but in addition to the refrigerant side flow suppression convex portion 140 or instead of the refrigerant side flow suppression convex portion 140. Thus, a similar refrigerant side flow suppression convex portion 142 that protrudes toward the refrigerant flow path may be provided at the same position as the refrigerant side flow suppression portion 42 in the gas separator 30.

E. Third embodiment:
FIG. 12 is a schematic cross-sectional view showing the configuration of the fuel cell 210 of the third embodiment at the same position as in FIG. The fuel cell 210 has the same configuration as that of the fuel cell 10 except for the portion related to the refrigerant side flow suppressing unit, and the same reference numerals are assigned to the portions common to the fuel cell 10 and detailed description thereof is omitted. FIG. 12 shows a cross-sectional view at the same position as in FIG. The fuel cell 210 includes a gasket 234 instead of the gasket 34, and a part of the gasket 234 provided on the refrigerant flow path side constitutes a refrigerant side flow suppressing portion. In the gasket 234, the fuel cell 10 is provided at the same position as the position where the refrigerant side flow suppressing portion 40 is disposed so as to extend toward the power generation region side, close the recess 80 of the gas separator 30, and close to the gas separator 31 side. A convex refrigerant side flow restraining portion 240 is formed. FIG. 13 is a plan view illustrating a configuration of a gasket 234 that is disposed on the refrigerant flow path side of the gas separator 30 and in which the refrigerant side flow suppressing portion 240 is formed. In FIG. 12 and FIG. 13, the part which is the refrigerant | coolant side flow suppression part 240 in the gasket 234 is enclosed and shown with the broken line.

  Also in the fuel cell 210 configured as described above, the refrigerant side flow suppressing unit 240 is provided, and the pressure loss ΔP1 when the refrigerant flows in the refrigerant channel forming unit 25 is closer to the outer periphery of the refrigerant channel forming unit 25. By increasing the pressure loss ΔP2 when the refrigerant flows sideways through the formed gap, the same effect as in the first embodiment can be obtained. At this time, as shown in FIG. 12, the refrigerant side flow suppression unit 240 does not need to be formed so as to block the entire space formed on the concave portion 80, and only needs to block at least a part of the space on the concave portion 80. It is sufficient that the pressure loss when the refrigerant flows side by side can be sufficiently increased. Further, according to the fuel cell 210, the refrigerant side flow suppressing portion 240 is formed integrally with the gasket 234, so that the effect of suppressing the number of parts can be obtained as compared with the first embodiment.

  The refrigerant side flow suppressing unit 240 can be variously modified in addition to the shapes shown in FIGS. For example, in FIG. 12, the refrigerant side flow suppressing portion 240 has a convex portion that comes into contact with the gas separator 31, but it is not necessary to ensure sealing performance at this convex portion, and thus the convex portion is the gas separator. It is good also as not touching 30. Alternatively, in addition to the refrigerant side flow suppression unit 240 or instead of the refrigerant side flow suppression unit 240, a refrigerant side flow suppression unit 242 that blocks at least a part of the space on the recess 81 of the gas separator 31 is integrated with the gasket 234. It is good also as providing. Moreover, you may arrange | position the convex shape of the gasket 234 in the direction reverse to a lamination direction. Specifically, the gasket 234 may be disposed on the gas separator 31 without providing the separator protrusion 74 in the gas separator 30, and the fifth linear protrusion 64 may be in contact with the gas separator 30. Even in such a case, the same effect as that of the third embodiment can be obtained by providing a refrigerant side flow suppressing portion that is integrated with the gasket 234 and blocks at least a part of the space on at least one of the concave portion 80 and the concave portion 81. Can be obtained.

F. Fourth embodiment:
FIG. 14 is a schematic cross-sectional view showing the configuration of the fuel cell 310 of the fourth embodiment at the same position as in FIG. The configuration of the fuel cell 310 is the same as that of the fuel cell 10 except for the portion related to the refrigerant side flow suppression unit, and portions common to the fuel cell 10 are denoted by the same reference numerals and detailed description thereof is omitted. The fuel cell 310 includes a refrigerant channel forming unit 325 instead of the refrigerant channel forming unit 25, and a part of the refrigerant channel forming unit 325 constitutes a refrigerant side flow suppressing unit. In the refrigerant flow path forming portion 325, the outer periphery of the refrigerant flow path forming portion 325 extends to the outer peripheral side of the separator at the same position as the position where the refrigerant side flow suppressing portion 40 is disposed in the fuel cell 10, and the space on the concave portion 80. The refrigerant side flow suppressing part 340 is provided so as to block the air. FIG. 15 is a plan view illustrating a configuration of a refrigerant flow path forming unit 325 that is disposed on the refrigerant flow path side of the gas separator 30 and in which the refrigerant side flow suppression unit 340 is formed. In FIG. 14 and FIG. 15, the part which is the refrigerant side flow suppression part 340 in the refrigerant | coolant flow path formation part 325 is enclosed and shown with the broken line.

  When the refrigerant flow path forming unit 325 is configured by, for example, a corrugated metal member, first, the refrigerant side flow suppressing unit 340 is handled by punching or the like from a metal flat plate before being formed into a corrugated plate. A member having a rectangular shape as a whole is provided, provided with a protruding portion serving as the refrigerant side flow suppressing portion 340 at the position. Then, the prepared member is pressed and processed into a corrugated sheet. About the said protrusion part, the refrigerant | coolant side flow suppression part 340 of the shape fitted in the recessed part 80 can be formed by further bending by press work. Alternatively, when the refrigerant flow path forming portion 325 is formed by a flat porous body, a member prepared separately from the quadrangular porous body is fixed to the porous body by bonding or fitting. Alternatively, the refrigerant side flow suppression unit 340 may be formed.

  Also in the fuel cell 310 configured as described above, the refrigerant side flow suppressing unit 340 is provided, and the pressure loss ΔP1 when the refrigerant flows in the refrigerant channel forming unit 325 is closer to the outer periphery of the refrigerant channel forming unit 325. By increasing the pressure loss ΔP2 when the refrigerant flows sideways through the formed gap, the same effect as in the first embodiment can be obtained. At this time, it is not necessary to form the refrigerant side flow suppression unit 340 so as to block the entire space formed on the recess 80 as shown in FIG. 14, and by blocking at least a part of the space on the recess 80, It is only necessary to sufficiently increase the pressure loss when the refrigerant flows sideways. Further, according to the fuel cell 310, the refrigerant side flow suppressing part 340 is formed integrally with the refrigerant flow path forming part 325, so that the number of parts can be suppressed as compared with the first embodiment. Further, when the fuel cell 310 is assembled, the refrigerant side flow suppressing part 340 of the refrigerant flow path forming part 325 may be fitted into the recess 80 of the gas separator 30, so that the refrigerant flow path forming part 325 is formed with respect to the gas separator 30. The operation of stacking while aligning can be facilitated.

  In addition, the refrigerant side flow suppressing portion provided in the refrigerant flow path forming portion 325 can be variously modified in addition to the shapes shown in FIGS. For example, in addition to the refrigerant side flow suppression unit 340 or instead of the refrigerant side flow suppression unit 340, a refrigerant side flow suppression unit 342 that blocks at least a part of the space on the recess 81 of the gas separator 31 is formed as a refrigerant flow path. It may be provided integrally with the portion 325.

G. Variations:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

G1. Modification 1:
In the first to third embodiments, in order to suppress the side flow of the refrigerant in the longitudinal sides (side a and side b) of the gas separator, the refrigerant side flow suppression unit is provided for each of the longitudinal sides. A different configuration may be used. The refrigerant side flow suppressing unit may be provided at a position where the side flow when the refrigerant flows in the plane serving as the inter-cell refrigerant flow path can be suppressed according to the arrangement of the refrigerant manifold. For example, a hole serving as a refrigerant supply manifold and a hole serving as a refrigerant discharge manifold are disposed in the vicinity of one corner of the power generation region, and the refrigerant swirls along the outer periphery of the power generation region in the refrigerant flow path. In such a case, the refrigerant side flow suppressing portion may be provided at one place on the outer periphery of the power generation region. In order to improve gas sealing performance between the outer periphery of the refrigerant flow path forming portion and the sealing position of the gasket that seals the inter-cell refrigerant flow path, and away from the refrigerant entrance / exit to the inter-cell refrigerant flow path When the concave portion is formed as an inverted shape of the separator convex portion, an effect of suppressing the side flow of the refrigerant can be obtained by providing the refrigerant side flow suppressing portion in such a concave portion. It is only necessary that the refrigerant side flow suppression unit is provided in the path along which the refrigerant flows side by side from the refrigerant inlet to the refrigerant outlet in the inter-cell refrigerant flow path.

G2. Modification 2:
In the first to third embodiments, in order to seal the gas flow path in the cell, two linear protrusions are formed on one gas separator, and the two linear shapes are formed on the other gas separator. Although one linear convex portion in contact with both convex portions is formed, a different configuration may be used. For example, a single linear convex portion is provided at a position where both gas separators overlap with each other, and the tops of the linear convex portions are brought into contact with each other via the MEA 20, thereby sealing the gas flow path in the cell. You may do it. In order to improve the gas sealing property, the separator convex portion provided at the position overlapping the linear convex portion in the gas separator may be provided in at least one of the gas separators, and the refrigerant side flow is suppressed in the concave portion as the back side shape of the separator convex portion. If a part is provided, the same effect which suppresses the side flow of the refrigerant | coolant resulting from a separator convex part will be acquired. In a fuel cell, when the position of the refrigerant seal in the stacking direction is closer to the outer periphery of the gas separator than the position of the gas seal in the stacking direction, the separator protrusion overlaps the linear protrusion for gas sealing If the gas separator is formed in a shape that is reversed, the side flow of the refrigerant can be promoted. In such a case, the same effect as in the embodiment can be obtained by providing a refrigerant side flow suppressing portion on the back side of the separator convex portion.

G3. Modification 3:
In the first to third embodiments, the fuel cell is a solid polymer fuel cell, but may have a different configuration. If the fuel cell is provided with a gasket in each of a pair of gas separators sandwiching the MEA and the gas flow path can be sealed by sandwiching the MEA with the gasket, the present invention can be applied to obtain the same effect. it can.

10, 110, 210, 310 ... Fuel cell 15 ... Single cell 20 ... MEA
21, 22 ... Gas diffusion layer 23, 24 ... Gas flow path forming part 25, 325 ... Refrigerant flow path forming part 30, 31, 131 ... Gas separator 32, 34, 35, 234 ... Gasket 33, 36 ... Sealing plate 38 ... Communicating holes 40, 42, 240, 242, 340, 342 ... Refrigerant side flow suppression part 50-59 ... Hole part 60 ... First linear convex part 61 ... Second linear convex part 62 ... Third linear convex part 63 ... 4th linear convex part 70,71,74 ... Separator convex part 80,81 ... Concave part 140,142 ... Refrigerant side flow suppression convex part

Claims (9)

A membrane-electrode assembly including an electrolyte membrane and electrodes formed on both surfaces of the electrolyte membrane, and a gas flow path disposed between the membrane-electrode assembly and the membrane-electrode assembly. A pair of separators, and a fuel cell formed by laminating a plurality of single cells,
A refrigerant flow path forming member that is disposed between the separators of each adjacent single cell and forms a part of a space that becomes a refrigerant flow path;
A gas flow path seal portion disposed between the pair of separators along the outer peripheral portion of the membrane-electrode assembly,
A refrigerant flow path seal portion that is provided so as to be in contact with both separators included in each adjacent single cell and seals the refrigerant flow path; and
With
At least one of the pair of separators has a separator convex portion that is convex to the membrane-electrode assembly side in a shape that is upside down at a position in contact with the gas flow path seal portion,
The gas flow path seal portion is provided by being bonded to one of the pair of separators, and is bonded to the first gas flow path seal member having the first gas seal convex portion and the other of the pair of separators. And a second gas flow path seal member having a second gas seal convex portion, and the membrane-electrode assembly is formed by the first gas seal convex portion and the second gas seal convex portion. By sandwiching, seal the gas flow path formed on both surfaces of the membrane-electrode assembly,
At least one of the first gas seal convex portion and the second gas seal convex portion is formed in a shape along the separator convex portion,
The refrigerant seal position where the refrigerant flow path seal portion contacts both of the adjacent separators is the gas seal position where the first gas seal convex portion and the second gas seal convex portion sandwich the membrane-electrode assembly. Than the outer peripheral side of the separator,
The fuel flow path is provided with a refrigerant side flow suppressing portion that closes at least a part of a space formed by a concave portion that is a reverse structure of the separator convex portion. The fuel cell according to claim 1, wherein
The refrigerant side flow restraint portion is composed of an independent member fitted into the recess. The fuel cell according to claim 1, wherein
The refrigerant side flow suppressing portion is convex with respect to the concave surface of the concave portion that is the reverse structure of the separator convex portion in the separator adjacent to the separator formed with the separator convex portion via the refrigerant flow path. A fuel cell, which is a protrusion provided on the fuel cell. The fuel cell according to claim 1, wherein
The refrigerant side flow suppression portion is formed integrally with the refrigerant flow path seal portion. The fuel cell according to claim 1, wherein
The refrigerant side flow suppressing portion is formed by extending a part of the outer periphery of the refrigerant flow path forming member. A fuel cell according to any one of claims 1 to 5,
The concave portion provided with the refrigerant side flow suppressing part is between the outer periphery of the refrigerant flow path forming member and the refrigerant flow path seal part, and the inflow part of the refrigerant into the refrigerant flow path, and A fuel cell provided at a position spaced apart from an outlet of the refrigerant from the refrigerant flow path. The fuel cell according to any one of claims 1 to 6,
The first and second gas seal convex portions are formed so as to surround the entire outer periphery of a power generation region where an electrochemical reaction proceeds in the membrane-electrode assembly,
The first gas seal member includes an inflow portion of the first gas into a first gas flow path formed between one of the pair of separators and the membrane-electrode assembly, and In the outflow part of the first gas from the first gas flow path, a first communication hole serving as a passage for the first gas is formed,
The second gas seal member includes an inflow portion of the second gas into a second gas flow path formed between the other of the pair of separators and the membrane-electrode assembly, and A second communication hole serving as a passage for the second gas is formed in an outflow portion of the second gas from the second gas flow path. The fuel cell according to claim 7, wherein
The top part of the second gas seal convex part is arranged at a position farther from the outer periphery of the power generation region than the top part of the first gas seal convex part,
The first gas seal convex portion and the second gas seal convex portion are in contact with each other through the membrane-electrode assembly on a side surface near the top of each convex portion. The fuel cell according to claim 8, wherein
The first gas seal member further includes a third gas formed so as to surround the entire outer periphery of the power generation region at a position farther from the entire outer periphery of the power generation region than the second gas seal convex portion. With seal convex
The second gas seal convex portion and the third gas seal convex portion are in contact with each other on a side surface near the top of each convex portion.

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