JP4026302B2 - Separator for fuel cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a separator for a fuel cell, and more particularly to a separator for a fuel cell that forms a partition wall between cells of a fuel cell stack formed by stacking a plurality of unit cells that receive power and generate electricity.
[0002]
[Prior art]
Conventionally, as a separator for this type of fuel cell, a separator in which a plurality of openings for supplying and discharging gas and the like in the stacking direction of the single cells in the fuel cell stack are arranged at the outer edge has been proposed (Japanese Patent Laid-Open No. 11) -339822). This opening communicates with another opening to form a fluid flow path, and gas is supplied from this fluid flow path to the unit cell. In addition, a separator in which a triangular opening is arranged at a corner has been proposed (Japanese Patent Laid-Open No. 4-47671). In this separator, the fluid flow path is formed to flow in parallel to the outer wall after flowing the gas substantially perpendicularly to the oblique side of the opening.
[0003]
[Problems to be solved by the invention]
However, in these separators, the opening portion needs a predetermined opening area in order to smoothly supply and discharge gas, but if the separator is to be downsized, the predetermined opening area cannot be secured. Thus, as a technique for securing a predetermined opening area, a technique of extending the opening in the outer direction of the separator is conceivable. However, in this technique, the outer shape of the separator swells and the separator becomes large. Although a method of extending the opening to the side of another adjacent opening is conceivable, this method restricts a place where the other opening is arranged and reduces the degree of freedom in design.
[0004]
The separator for a fuel cell according to the present invention has an object of securing an opening area of an opening through which fuel is supplied to and discharged from a single cell without increasing the size of the separator. Another object of the separator for a fuel cell according to 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 their functions and effects]
The separator for a fuel cell of the present invention employs the following means in order to achieve at least a part of the above object.
[0006]
The separator for the first fuel cell of the present invention is:
Formed as a partition between cells of a fuel cell stack formed by stacking a plurality of unit cells that generate power upon receiving fuel supply, and to form a plurality of pairs of supply / discharge channels in the stacking direction in the fuel cell stack A separator for a fuel cell , comprising: a plurality of pairs of openings provided in a fluid passage; and a flow path forming portion that forms a fluid flow path through which fluid flows and communicates with at least a pair of openings of the plurality of pairs of openings. Because
The fluid flow path of the flow path forming portion is formed in a zigzag shape by a plurality of folded portions,
At least one of the plurality of pairs of openings has a hypotenuse having a predetermined angle with respect to the fluid flow, facing a folded portion where the fluid is first folded in the fluid flow path, It is formed as an extended opening extending in the fluid flow path direction.
[0007]
In the first fuel cell separator of the present invention, the opening is formed as an extended opening extending in the direction of the fluid flow path, so that the outer shape of the separator is not expanded, that is, the separator is large-sized. A predetermined opening area can be ensured without the need for conversion. Moreover, since an opening part is extended in the fluid flow path direction, it does not restrict | limit the place which arrange | positions another opening part. As a result, it is possible to prevent a reduction in design freedom.
[0008]
In the first fuel cell separator of the present invention, at least one of the openings formed at the four corners of the plurality of pairs of openings is formed as an extended opening extending in the fluid flow path direction. It can also be. In this way, even if the openings are formed at the four corners, a predetermined opening area can be secured without expanding the outer shape of the separator.
[0009]
In the first fuel cell separator according to the present invention, the extension opening is formed in a direction of the fluid flow path in the direction of the folded portion where the fluid is folded back with respect to the fluid flow in the fluid flow path. It can also have a hypotenuse that tilts at an acute angle . In this way, the wall surface of the folded portion of the other fluid flow path that is folded next to the extension opening can have an angle that forms an acute angle with the fluid flow path direction in the direction of the folded portion where the fluid is folded back next. The fluid flow in the folded portion can be made smooth.
[0010]
In the first fuel cell separator of the present invention, the pair of openings including the extension opening of the plurality of pairs of openings may be formed along the same side wall. .
[0011]
The separator for the second fuel cell of the present invention is
It name the partition wall between unit cells of a fuel cell stack the unit cells for generating electricity by being supplied with fuel formed by stacking a plurality and the opening of the rectangular shape, with a separator of a rectangular shape having a fluid flow path through which fluid flows There,
A polygonal corner opening having at least one of the four corners having three sides parallel to the outer wall and at least one inner oblique side that forms an acute angle with the outer wall in the fluid flow path direction in the fluid traveling direction. This is the gist.
[0012]
In the second fuel cell separator of the present invention, at least one side inside the corner opening is formed at an angle that makes an acute angle with the outer wall in the fluid flow path direction in the fluid traveling direction with respect to the outer wall . The rectangular shape of the separator can be maintained and a predetermined opening area can be secured without increasing the size of the separator. Moreover, since the place which arrange | positions another opening part is not restrict | limited, the fall of the freedom degree of design can be prevented.
[0013]
In such a separator for the second fuel cell of the present invention, the corner opening is an opening for supplying fluid to or discharging fluid from a fluid flow path communicating with the other formed opening. You can also In this way, a predetermined opening area can be secured while maintaining the rectangular shape of the separator, so that the fluid can be supplied or discharged satisfactorily. In this aspect of the fuel cell separator according to the present invention, the corner opening is an opening that supplies or discharges fluid to or from a fluid passage that communicates with another formed opening. You can also.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described using examples. FIG. 1 is a configuration diagram showing an outline of a configuration of a fuel cell stack 100 including a separator 20 as one embodiment of the present invention. In the fuel cell stack 100, the unit cells 10 that generate power upon supply of fuel and separators 20 that are arranged between the unit cells and that form a partition between the unit cells and supply fuel to the unit cells 10 are alternately arranged. It is configured to be stacked.
[0015]
Although not shown, the unit cell 10 is configured as 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 generates electricity by supplying hydrogen-rich fuel gas and air.
[0016]
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, 24 a, 24 b, 26 a, and 26 b formed at the edge and a flow groove that communicates between the openings 22 a and 22 b. 28. As shown in FIG. 1, the unit cells 10 and the separators 20 are alternately stacked, so that each opening communicates in the stacking direction of the unit cells 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. 2 is formed on the back side of the separator 20 in FIG. 2, similar to the flow groove 28 that communicates the openings 24 a and 24 b.
[0017]
The openings 22b and 24b at the corners are formed as quadrilaterals having three sides parallel to the outer wall of the separator 20 and an oblique side with an acute angle with respect to the outer wall, and extend in the direction of the flow path formed by the flow grooves 28. Has been. As a result, the opening areas of the openings 22b and 24b can be increased without expanding the outer shape of the separator 20, and air or fuel gas can be discharged from the openings 22b and 24b satisfactorily.
[0018]
The circulation groove 28 is formed in a zigzag manner by the folded portions 32, 34, and 36, and includes a plurality of ribs 30 at the bottom. When the unit cell 10 and the separator 20 are stacked, the opening 22 a and the opening 22 b are provided. Is formed. A 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, the wall surface is inclined with 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 being trapped at the corners when folded at the folded portion 32.
[0019]
The fuel cell stack 100 is also provided with another separator (not shown) having a flow groove communicating the openings 26a and 26b. By supplying and discharging cooling water to and from the openings 26a and 26b, The fuel cell stack 100 can be cooled.
[0020]
According to the separator 20 of the present embodiment described above, the openings 22b and 24b have a quadrilateral shape including three sides parallel to the outer wall and an oblique side that is acute with respect to the outer wall, and has a shape extending in the fluid flow path direction. Thus, the opening area can be increased without expanding the outer shape of the separator 20, and the air or fuel gas can be discharged well. And since the wall surface of the folding | turning part of a circulation groove is inclined, air or fuel flows smoothly without stagnating in the corner | angular part of this wall surface.
[0021]
In the separator 20 of the present embodiment, the inner sides of the openings 22b and 24b are inclined at an acute angle with respect to the outer wall. However, the four sides of the openings 22b and 24b are parallel to the outer wall. It may be rectangular and may be extended in the flow path direction.
[0022]
Further, in the separator 20 of the present embodiment, the inner sides of the corner openings 22b and 24b are inclined at an acute angle with respect to the outer wall, but the inner sides of the corner openings 22a and 24a are It may be inclined at an acute angle with respect to the outer wall.
[0023]
Furthermore, in the separator 20 of the present embodiment, the opening shapes of the openings 22b and 24b are quadrilaterals, but are not limited to quadrilaterals, but are other polygons whose inner sides are inclined with respect to the outer wall. You can also
[0024]
In the separator 20 of the present embodiment, the unit cell 10 is a solid polymer electrolyte fuel cell. However, the unit cell is not limited to this, and may be another unit cell. In this case, the fuel gas supplied from the opening can be appropriately changed.
[0025]
The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an outline of 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. FIG.
[Explanation of symbols]
10 unit cells, 20 separators, 22a, 22b, 24a, 24b, 26a, 26b openings, 28 flow channels, 100 fuel cell stacks.

Claims (7)

Formed as a partition between cells of a fuel cell stack formed by stacking a plurality of unit cells that generate power upon receiving fuel supply, and to form a plurality of pairs of supply / discharge channels in the stacking direction in the fuel cell stack A separator for a fuel cell , comprising: a plurality of pairs of openings provided in a fluid passage; and a flow path forming portion that forms a fluid flow path through which fluid flows and communicates with at least a pair of openings of the plurality of pairs of openings. Because
The fluid flow path of the flow path forming portion is formed in a zigzag shape by a plurality of folded portions,
At least one of the plurality of pairs of openings has a hypotenuse having a predetermined angle with respect to the fluid flow, facing a folded portion where the fluid is first folded in the fluid flow path, A separator for a fuel cell, formed as an extended opening extending in the fluid flow path direction.   2. The fuel cell separator 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 extended opening extending in the fluid flow path direction. Said extension opening to the flow of the fluid in the fluid flow path, the direction of the folded portion in which the fluid is then folded back, claim 1 or 2 having a hypotenuse inclined form the fluid flow path direction at an acute angle The separator for fuel cells as described.   The separator for a fuel cell according to any one of claims 1 to 3, wherein the pair of openings including the extended opening of the plurality of pairs of openings is formed along the same side wall. It name the partition wall between unit cells of a fuel cell stack the unit cells for generating electricity by being supplied with fuel formed by stacking a plurality and the opening of the rectangular shape, with a separator of a rectangular shape having a fluid flow path through which fluid flows There,
A polygonal corner opening having at least one of the four corners having three sides parallel to the outer wall and at least one inner oblique side that forms an acute angle with the outer wall in the fluid flow path direction in the fluid traveling direction. Separator for fuel cells.   6. The fuel cell separator according to claim 5, wherein the corner opening is an opening for supplying fluid to or discharging fluid from a fluid flow path communicating with another formed opening.   The separator for a fuel cell according to claim 6, wherein the corner opening and the other opening are formed along the same side wall.

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