JP2002025585A - Separator for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the area of an opening section through which a fuel is supplied/discharged to a single cell, without enlarging a separator, in the separator for fuel cells. SOLUTION: Air introduced from an opening 22a is discharged from an opening 22b through a fluid path formed of a distribution slot 28. The opening 22b is quadrilateral and composed of three sides parallel to outer walls, and an oblique side of an acute angle, and the oblique side is extended in the direction of a path of the separator 20. Consequently, the area of the opening 22b can be widened without swelling the outside form of the separator 20, and air can be discharged well from the opening 22b. Moreover, the surface of a wall of a folded section 32 of the distribution slot 28 which adjoins the oblique side of the opening 24b is formed with a predetermined angle to the outer wall. Then, the air introduced from the opening 22a can flow smoothly, without stagnating in the angle section of the folded section 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separator for a fuel cell, and more particularly, to a fuel cell forming a partition between cells of a fuel cell stack formed by stacking a plurality of cells for generating electricity by supplying fuel. And a separator for the same.

[0002]

2. Description of the Related Art Heretofore, as a separator for a fuel cell of this type, a separator in which a plurality of openings for supplying and discharging gas and the like in a stacking direction of cells in a fuel cell stack are arranged at an outer edge has been proposed. (JP-A-11-339822). The opening is paired with another opening to form a fluid flow path, from which gas is supplied to the unit cell. A separator having a triangular opening at a corner has also been proposed (Japanese Patent Laid-Open No. 4-47671). In this separator, the fluid flow path is formed so that the gas flows substantially perpendicularly to the oblique side of the opening and then flows in parallel to the outer wall.

[0003]

However, in these separators, the opening requires a predetermined opening area in order to smoothly supply and discharge gas. However, in order to reduce the size of the separator, a predetermined opening area is required. The opening area cannot be secured. Then, as a method of securing a predetermined opening area, a method of extending the opening outward of the separator can be considered. However, in this method, the outer shape of the separator expands and the size of the separator increases. Further, a method of extending the opening to the side of the other opening adjacent thereto is also conceivable. However, in this method, the place where the other opening is arranged is limited, and the degree of freedom in design is reduced.

An object of the separator for a fuel cell of the present invention is to secure an opening area of an opening for supplying and discharging fuel to a unit cell without increasing the size of the separator. Another object of the separator for a fuel cell of the present invention is to secure the opening area of the opening without reducing the degree of freedom in design.

[0005]

Means for Solving the Problems and Actions / Effects The fuel cell separator of the present invention employs the following means in order to achieve at least a part of the above objects.

[0006] The first fuel cell separator of the present invention forms a partition wall between cells of a fuel cell stack in which a plurality of cells that receive power and are supplied with fuel to generate electric power. A plurality of pairs of openings provided on an edge portion to form a plurality of pairs of supply and discharge channels in the stacking direction, and a fluid channel communicating with at least one pair of the plurality of pairs of openings are formed. A fuel cell separator comprising a flow path forming portion, wherein at least one of the plurality of pairs of openings is formed as an extended opening extending in the fluid flow direction. And

In the first fuel cell separator of the present invention, the opening is formed as an extension opening extending in the fluid flow direction, so that the outer shape of the separator is not expanded, that is, A predetermined opening area can be secured without increasing the size of the separator. Further, since the opening is extended in the direction of the fluid flow path, the place where another opening is arranged is not limited. As a result, it is possible to prevent a decrease in the degree of freedom in design.

In the first fuel cell separator of the present invention, at least one of the plurality of pairs of openings formed at four corners is formed as an extension opening extending in the fluid flow direction. It can also be made. In this way, even with the openings formed at the four corners, a predetermined opening area can be secured without expanding the outer shape of the separator.

In the first fuel cell separator according to the present invention, the extension opening may have a hypotenuse having a predetermined angle with respect to the flow of the fluid in the fluid flow path. With this configuration, the wall surface of the folded portion of another fluid flow path that is folded next to the extension opening can have a predetermined angle, and the flow of fluid in the folded portion can be smooth.

In the fuel cell separator according to the first aspect of the present invention, a pair of openings including the extension opening of the plurality of pairs of openings are formed along the same side wall. You can also.

The second separator for a fuel cell according to the present invention is a rectangular separator forming a partition between the cells of a fuel cell stack formed by stacking a plurality of cells which receive power and generate power. At least one of the four corners has a polygonal corner opening having three sides parallel to the outer wall and at least one inner hypotenuse formed at a predetermined angle different from 90 degrees with respect to the outer wall. Make a summary.

In the second fuel cell separator of the present invention, at least one side inside the corner opening is formed at a predetermined angle different from 90 degrees with respect to the outer wall.
A predetermined opening area can be secured without increasing the size of the separator by maintaining the rectangular shape of the separator. In addition, since the place where the other opening is arranged is not limited, it is possible to prevent the degree of freedom of design from lowering.

In the fuel cell separator according to the second aspect of the present invention, the corner opening is an opening for supplying or discharging a fluid to a fluid flow path communicating with another opening formed. It can be. With this configuration, a predetermined opening area can be secured while maintaining the rectangular shape of the separator, so that the supply or discharge of the fluid to or from the fluid flow path can be favorably performed. In the fuel cell separator according to the aspect of the present invention, the corner opening is an opening for supplying or discharging a fluid to a fluid flow path communicating with another opening formed. Can also.

[0014]

Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram schematically showing a configuration of a fuel cell stack 100 including a separator 20 as one embodiment of the present invention. Fuel cell stack 100
Is a cell 10 that receives power and generates electric power, and that is disposed between the cells and forms a partition between the cells and that the cells 1
And the separators 20 for supplying fuel to the fuel cell 0 are alternately stacked.

Although not shown, the cell 10 is, for example, a solid polymer electrolyte fuel cell in which a solid polymer electrolyte membrane sandwiched between two catalyst electrodes is further sandwiched between two gas diffusion electrodes. It is configured to generate power by receiving supply of hydrogen-rich fuel gas and air.

FIG. 2 is a perspective view showing the appearance of the separator 20. The separator 20 has a rectangular outer shape, and has six openings 22 a, 22 b, 2 formed at the edges.
4a, 24b, 26a, 26b and openings 22a and 22
b. As shown in FIG. 1, by alternately stacking the unit cells 10 and the separators 20, the openings communicate with each other in the unit cell stacking direction to form a flow path. These flow paths are used as an air supply / discharge flow path, a fuel gas supply / discharge flow path, or a cooling water supply / discharge flow path. In addition, on the back side of the separator 20 in FIG.
A flow groove similar to the flow groove 28 that communicates with the flow path 24b is formed.

The opening portions 22b and 24b at the corners are formed as a quadrilateral having three sides parallel to the outer wall of the separator 20 and an oblique side that is acute to the outer wall. Is extended in the direction. As a result, the openings 22 can be formed without expanding the outer shape of the separator 20.
The opening areas of b and 24b can be increased, and air or fuel gas can be discharged well from openings 22b and 24b.

The flow grooves 28 are provided with folded portions 32, 34, 3
6, a plurality of ribs 3 are formed at the bottom.
0, and when the unit cell 10 and the separator 20 are stacked, a fluid flow path that connects the opening 22a and the opening 22b is formed. Part of the air supplied to the opening 22a is supplied to the unit cell 10 when passing through the fluid flow path, and the rest is discharged from the opening 22b. Since the wall surface of the folded portion 32 is adjacent to the oblique side of the opening 24b, it is formed to be inclined at a predetermined angle with respect to the outer wall of the separator 20a. As a result, the air supplied to the opening 22a can flow smoothly without stagnation at the corners when being turned back at the turn-back portion 32.

The fuel cell stack 100 is also provided with another separator (not shown) having a flow groove communicating with the openings 26a and 26b.
The fuel cell stack 1 is supplied to and discharged from the fuel cell stack 6a, 26b.
00 can be cooled.

According to the separator 20 of the present embodiment described above, the openings 22b and 24b are formed in a quadrangular shape having three sides parallel to the outer wall and an oblique side acute to the outer wall, and are extended in the fluid flow direction. By making the shape, the separator 20
The opening area can be increased without expanding the outer shape of the device, and air or fuel gas can be discharged well. In addition, since the wall surface of the folded portion of the flow groove is formed to be inclined, air or fuel flows smoothly without stagnation at the corner of the wall surface.

In the separator 20 of this embodiment, the opening 2
Although the inner sides of 2b and 24b are inclined at an acute angle to the outer wall, the opening shapes of the openings 22b and 24b are 4
The side may be a rectangle parallel to the outer wall, and may be extended in the flow channel direction.

In the separator 20 of this embodiment, the sides inside the corner openings 22b and 24b are inclined at an acute angle with respect to the outer wall, but the corner openings 22a and 2b are inclined.
The inner side of 4a may be inclined at an acute angle to the outer wall.

Further, in the separator 20 of this embodiment,
The opening shapes of the openings 22b and 24b are quadrilaterals, but are not limited to quadrilaterals, and may be other polygons whose inner sides are inclined with respect to the outer wall.

In the separator 20 of this embodiment,
The unit cell 10 is a solid polymer electrolyte type fuel cell, but is not limited to this, and may be another type of unit cell. In this case, the fuel gas or the like supplied from the opening can be appropriately changed.

The embodiments of the present invention have been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various embodiments may be made without departing from the gist of the present invention. Of course, it can be carried out.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a configuration of a fuel cell stack including a separator as one embodiment of the present invention.

FIG. 2 is a perspective view showing an appearance of a separator 20.

[Explanation of symbols]

10 cells, 20 separators, 22a, 22b, 2
4a, 24b, 26a, 26b openings, 28 flow grooves, 100 fuel cell stack.

Claims (7)

[Claims] 1. A fuel cell stack comprising a plurality of unit cells that receive a supply of fuel and generate power, form a partition between the unit cells, and a plurality of pairs of supply / discharge flow paths in the stacking direction are formed in the fuel cell stack. A fuel cell comprising: a plurality of pairs of openings provided in an edge portion to be formed; and a flow path forming section that forms a fluid flow path communicating with at least one pair of the plurality of openings. A separator for a fuel cell, wherein at least one of the plurality of pairs of openings is formed as an extension opening extending in the fluid flow direction. 2. The fuel cell according to claim 1, wherein at least one of the openings formed at four corners of the plurality of pairs of openings is formed as an extension opening extending in the fluid flow direction. Separator. 3. The fuel cell separator according to claim 1, wherein the extension opening has a hypotenuse having a predetermined angle with respect to the flow of the fluid in the fluid flow path. 4. The fuel cell according to claim 1, wherein a pair of openings including the extension opening of the plurality of pairs of openings are formed along the same side wall. Separator. 5. A rectangular separator serving as a partition between unit cells of a fuel cell stack formed by stacking a plurality of unit cells that receive a supply of fuel and generate electric power, wherein at least one of the four corners is parallel to an outer wall. A fuel cell separator having a polygonal corner opening having three sides and at least one inner hypotenuse formed at a predetermined angle different from 90 degrees with respect to the outer wall. 6. The fuel cell separator according to claim 5, wherein the corner opening is an opening for supplying or discharging a fluid to a fluid flow path communicating with another opening formed. . 7. The fuel cell separator according to claim 6, wherein the corner opening and the other opening are formed along the same side wall.