JP2018067380A - Fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel battery which enables the suppression of the rise in the pressure in a casing of a fuel battery configured so that a laminate is encased in the casing.SOLUTION: A fuel battery 100 comprises: a laminate including a plurality of single cells laminated; a casing for encasing the laminate, which has a first wall part 41B and a second wall part 41R crossing the first wall part and having a high stiffness higher than that of the first wall part; and a porous body part 50 disposed at a corner corresponding to an intersection of the first and second wall parts in the casing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel cell.

  A fuel cell having a configuration in which a fuel cell stack including a stack of a plurality of single cells is accommodated in a case is disclosed (Patent Document 1).

JP 2016-12408 A

  When the fuel cell described in Patent Document 1 is mounted on a vehicle and used, for example, a reaction gas (for example, hydrogen gas) supplied to the fuel cell stack abnormally burns in the fuel cell stack due to a vehicle collision, and the combustion This may cause a problem that the gas or reaction gas generated by the leakage from the fuel cell causes the pressure in the case to increase excessively. If the pressure in the case increases excessively, the entire fuel cell including the fuel cell stack may be damaged. The above-described problems are not limited to fuel cells mounted on vehicles, but are common to fuel cells having a configuration in which a fuel cell stack is accommodated in a case, such as a fuel cell fixedly disposed in a building. Therefore, in a fuel cell having a configuration in which the fuel cell stack is accommodated in a case, a technique for suppressing an increase in pressure in the case is desired.

  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.

  (1) According to one embodiment of the present invention, a fuel cell is provided. The fuel cell includes: a stacked body including a plurality of stacked single cells; a first wall, and a second wall that intersects the first wall and has higher rigidity than the first wall. And a case that accommodates the laminated body; and a porous body portion that is disposed inside the case at a corner corresponding to the intersection of the first wall portion and the second wall portion. .

  According to the fuel cell of this aspect, the case includes the first wall portion and the second wall portion that intersects the first wall portion and has higher rigidity than the first wall portion. When the gas generated by abnormal combustion leaks from the laminate and the pressure in the case rises excessively, the pressure in the case is released by intentionally destroying the first wall near the intersection. , Increase in pressure in the case can be suppressed. In addition, even when the first wall portion is destroyed in this way, the porous body portion is disposed at the corner corresponding to the intersecting portion, so that while the pressure in the case is being released, the porous body portion It is possible to suppress a member having a diameter larger than the hole from entering the case.

  The present invention can be realized in various forms. For example, it can be realized in the form of a fuel cell system including a fuel cell, a vehicle including the fuel cell system, and the like.

It is a perspective view showing a schematic structure of a fuel cell in one embodiment of the present invention. It is sectional drawing which shows the 2-2 cross section shown in FIG. It is an enlarged view of the area | region shown in FIG. It is a perspective view which expands and shows the opening part of the case in the fuel cell at the time of abnormal combustion generation | occurrence | production. It is an enlarged view which shows the area | region at the time of abnormal combustion occurrence.

A. Embodiment:
A1. Fuel cell configuration:
FIG. 1 is a perspective view showing a schematic configuration of a fuel cell 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a 2-2 cross section shown in FIG. In FIGS. 1 and 2, the Z axis is set parallel to the vertical direction, and the X axis and Y axis are set parallel to the horizontal direction. The + Z direction corresponds to the vertically upward direction, and the −Z direction corresponds to the vertically downward direction. Note that the X axis, Y axis, and Z axis in FIG. 1 correspond to the X axis, Y axis, and Z axis in other drawings.

  As shown in FIGS. 1 and 2, the fuel cell 100 includes a fuel cell stack 90, a case 40, and a plurality of bolts 80. As shown in FIG. 1, the fuel cell 100 has a configuration in which a fuel cell stack 90 is accommodated in a case 40. In FIG. 1, the case lid 40b shown in FIG. 2 is omitted as the case 40, and only the case main body 40a is shown. In FIG. 2, for the convenience of explanation, the porous body portion 50 shown in FIG. 1 is represented by a broken line and hatched as in FIG. 1.

  As shown in FIG. 2, the fuel cell stack 90 includes a stacked body 10, a first end plate 20 a, a second end plate 20 b, and a pressure plate 30. The stacked body 10 includes a plurality of single cells 11 stacked along a stacking direction (hereinafter simply referred to as “stacking direction”) that is a direction substantially parallel to the X axis. Specifically, the laminated body 10 includes a plurality of single cells 11, a pair of terminal plates 12, and a pair of insulators 13.

  Each unit cell 11 is a solid polymer fuel cell in this embodiment, and uses a reaction gas supplied to an anode side catalyst electrode layer and a cathode side catalyst electrode layer provided with a solid polymer electrolyte membrane interposed therebetween. Electricity is generated by the electrochemical reaction. In the present embodiment, the reaction gas (fuel gas) on the anode side is hydrogen gas. The reaction gas (oxidant gas) on the cathode side is air. In the present embodiment, the catalyst electrode layer of each electrode includes carbon particles supporting platinum (Pt) as a catalyst and an electrolyte.

  In each single cell 11, a gas diffusion layer formed of a porous body is disposed outside the catalyst electrode layer of each electrode. As the porous body, for example, carbon porous bodies such as carbon paper and carbon cloth, and metal porous bodies such as metal mesh and foam metal are used. In addition, a conductive separator is disposed outside the gas diffusion layer of each electrode. Inside the fuel cell stack 90, there are a plurality of manifolds for supplying reaction gas to each single cell 11, discharging off-gas from each single cell 11, and supplying and discharging cooling medium to each single cell 11. And formed substantially parallel to the stacking direction.

  A pair of terminal plate 12 consists of a plate-shaped electroconductive member, and functions as a comprehensive electrode. Each terminal plate 12 is arranged adjacent to the outer surface of each outermost unit cell 11 in the stacking direction of the stacked body of the plurality of unit cells 11. Specifically, the terminal plate 12 on the + X direction side of the fuel cell stack 90 is disposed on the outer side (+ X direction) of the stack direction of the single cells 11 located at the end in the + X direction of the stack of the single cells 11. ing. The terminal plate 12 on the −X direction side of the fuel cell stack 90 is arranged on the outer side (−X direction) in the stacking direction of the single cells 11 positioned at the −X direction end of the stacked body of the plurality of single cells 11. .

  The pair of insulators 13 is made of a plate-like insulating member, and is electrically connected between one terminal plate 12 and the first end plate 20a and between the other terminal plate 12 and the second end plate 20b. Insulate. Each insulator 13 is disposed adjacent to the outer surface of each terminal plate 12 in the stacking direction. Specifically, the insulator 13 on the + X direction side of the fuel cell stack 90 is in the stacking direction with respect to one surface (the surface in the + X direction) of the two surfaces in the stacking direction of the terminal plate 12 on the + X direction side. It is arranged outside (+ X direction). The insulator 13 on the −X direction side of the fuel cell stack 90 has an outer side in the stacking direction with respect to one surface (surface in the −X direction) of two surfaces in the stacking direction of the terminal plate 12 on the −X direction side. -X direction).

  The first end plate 20a is located on the outer side (+ X direction) in the stacking direction with respect to one of the two surfaces in the stacking direction of the stacked body 10 (the surface in the + X direction). Specifically, the first end plate 20a is disposed on the outer side (+ X direction) in the stacking direction of the insulator 13 located at the end of the stacked body 10 in the + X direction. The first end plate 20a is a plate-like member. The first end plate 20a, together with the second end plate 20b described later and the pressure plate 30 described later, sandwich the stacked body 10 with a predetermined compressive force, and holds the stacked state of the stacked body 10. In the present embodiment, the first end plate 20a is made of aluminum. In addition, it may replace with aluminum and may be formed with metals and alloys, such as steel and titanium. The planar view shape (contour shape when viewed in the −X direction) of the first end plate 20a is substantially rectangular.

  The first end plate 20a has a plurality of through holes (not shown) penetrating in the thickness direction (X-axis direction). The plurality of through holes communicate with a plurality of manifolds (not shown) formed inside the stacked body 10, supply reactive gas and cooling medium to the stacked body 10, and discharge off-gas and cooling medium from the stacked body 10. Used for.

  The second end plate 20b is an outer side in the stacking direction with respect to a surface (−X direction) opposite to the side on which the first end plate 20a is disposed, of the two surfaces in the stacking direction of the stacked body 10. Located in (−X direction). Specifically, the insulator 13 positioned at the end in the −X direction of the stacked body 10 is disposed outside (−X direction) in the stacking direction. The second end plate 20b has the same shape as the first end plate 20a and is made of the same material as that of the first end plate 20a.

  The pressure plate 30 is disposed adjacent to one surface (surface in the −X direction) of the two surfaces in the stacking direction of the second end plate 20b (the surface in the −X direction) on the outer side in the stacking direction (−X direction). Yes. The pressure plate 30 has the same shape as that of the first end plate 20a and is made of the same material as that of the first end plate 20a. The pressure plate 30 is joined to the case 40 by a plurality of bolts 80. A fastening load is applied to the fuel cell stack 90 in a state where the pressure plate 30 and the case 40 are joined.

  As shown in FIG. 2, the case 40 includes a case body 40a and a case lid 40b. As shown in FIGS. 1 and 2, the case main body 40 a has a bottomed cylindrical external shape in which an opening is formed at an end on the + X direction side and an end on the opposite side (−X direction side) is closed. Have As shown in FIG. 2, the case lid 40b is fastened to the case body 40a so as to cover the opening of the case body 40a. More specifically, the case main body 40a has a flange extending around the opening of the case main body 40a along the direction from the center of the opening toward the edge of the opening. The flange portion is in contact with the surface in the −X direction of the case lid portion 40 b and is connected to the peripheral edge portion of the case lid portion 40 b by a plurality of bolts 80. The case 40 is excellent in waterproofness, dustproofness, and impact resistance, and is formed of aluminum in this embodiment.

  As shown in FIG. 1, the case main body 40a is formed of the above-described flange portion and a plurality of wall portions. The plurality of wall portions described above include a first wall portion 41B, a second wall portion 41R, a third wall portion 41E, a fourth wall portion 41L, and a fifth wall portion 41T.

  The first wall portion 41B intersects with the second wall portion 41R and the fourth wall portion 41L to form the bottom wall of the case main body portion 40a. The second wall portion 41R intersects the first wall portion 41B, the third wall portion 41E, and the fifth wall portion 41T, and forms the right side wall portion of the case main body portion 40a when viewed in the −X direction. The third wall portion 41E intersects the first wall portion 41B, the second wall portion 41R, the fourth wall portion 41L, and the fifth wall portion 41T, respectively, and sees in the −X direction, so that the rear wall of the case main body portion 40a. Forming part. The fourth wall portion 41L intersects the first wall portion 41B, the third wall portion 41E, and the fifth wall portion 41T, respectively, and forms the left side wall portion of the case main body portion 40a when viewed in the −X direction. The fifth wall portion 41T intersects the second wall portion 41R, the third wall portion 41E, and the fourth wall portion 41L to form a ceiling wall portion of the case main body portion 40a. As shown in FIG. 1, a case 40 (case main body defined by a first wall portion 41B, a second wall portion 41R, a third wall portion 41E, a fourth wall portion 41L, and a fifth wall portion 41T. The fuel cell stack 90 is arranged in the internal space of the part 40a).

  As shown in FIG. 1, the porous body part 50 is arrange | positioned at the two corner | angular parts 42a and 42b inside the case main-body part 40a, respectively. The corner 42a is a region corresponding to the intersection of the first wall 41B and the fourth wall 41L. The corner portion 42b is a region corresponding to the intersection between the first wall portion 41B and the second wall portion 41R. Here, the “region corresponding to the intersection between the wall and the wall” means a region in the vicinity of the intersection between the wall and the wall and within a predetermined distance from each wall. To do. Therefore, a part of the corner portion may be in contact with at least one wall portion, or may be separated from at least one wall portion within a predetermined distance.

  FIG. 3 is an enlarged view of the region Ar1 shown in FIG. The region Ar1 is a region including a corner 42b near the opening of the case main body 40a. In FIG. 3, illustration of the fuel cell stack 90 accommodated in the case 40 is omitted. As shown in FIGS. 2 and 3, the porous body 50 has a triangular prism-like appearance, and is disposed along the stacking direction from the opening of the case main body 40a to the third wall 41E. Yes. As shown in FIGS. 2 and 3, the porous body portion 50 is disposed in the corner portion 42 b inside the case 40 in contact with the first wall portion 41 </ b> B and the second wall portion 41 </ b> R. The cross-sectional shape of the surface parallel to the XY plane and the surface parallel to the YZ plane of the porous body portion 50 is substantially rectangular. The porous body portion 50 has a mesh shape in which a large number of holes are formed. In FIGS. 2 and 3, the holes formed in the porous body portion 50 are schematically shown. The rigidity of the porous body 50 is such that abnormal combustion of the reaction gas occurs in the fuel cell stack 90 (hereinafter referred to as “when abnormal combustion occurs”), and the gas or reaction gas generated by the abnormal combustion is the fuel cell stack. The rigidity is set such that it does not break when leaking from 90 and the pressure in the case 40 suddenly increases. Such rigidity control can be realized, for example, by adjusting the size, number, shape, and the like of the holes formed in the porous body portion 50. In the present embodiment, the porous body portion 50 is formed by combining mesh-shaped punching members. Instead of the punching member, any other member such as a metal mesh may be used as long as the member is formed with a hole through which the reaction gas can pass. Since the configuration in the vicinity of the corner 42a is the same, the description thereof is omitted.

  As shown in FIG. 3, the thickness t1 (length in the Z-axis direction) of the first wall portion 41B is smaller than the thickness t2 (length in the Y-axis direction) of the second wall portion 41R. In the present embodiment, the thicknesses t1 and t2 mean the average thickness of the respective wall portions 41B and 41R. As described above, since each wall portion (case 40) is formed of the same member (aluminum), the first wall portion 41B and the second wall portion 41R are provided with a difference in rigidity depending on the thickness. . That is, the second wall portion 41R has higher rigidity than the first wall portion 41B. Although illustration is omitted, in the present embodiment, the thicknesses of the third wall portion 41E, the fourth wall portion 41L, and the fifth wall portion 41T are the same as the thickness t2 of the second wall portion 41R.

A2. The state of the fuel cell 100 when abnormal combustion occurs:
FIG. 4 is an enlarged perspective view showing the opening of the case 40 in the fuel cell 100 when abnormal combustion occurs. Abnormal combustion occurs in the fuel cell stack 90 accommodated in the case 40, and gas and reaction gas generated by the abnormal combustion leak from the fuel cell stack 90, and the pressure in the case 40 increases. At this time, the first wall portion 41B having low rigidity and more fragile is destroyed. Particularly, in the first wall portion 41B, the first wall portion 41B is easily broken at the connection portion with the second wall portion 41R and the fourth wall portion 41L having higher rigidity than the first wall portion 41B. Accordingly, the first wall portion 41B is broken at the corner portions 42a and 42b, and the gap 70 is formed.

  FIG. 5 is an enlarged view showing a region Ar1 when abnormal combustion occurs. In FIG. 5, as in FIG. 3, illustration of the fuel cell stack 90 accommodated in the case 40 is omitted. As shown in FIG. 5, the end portion in the −Y direction of the first wall portion 41 </ b> B is broken, and a gap 70 is formed in the case 40. The void 70 is blocked by the porous body portion 50. However, since a large number of holes are formed in the porous body portion 50, the gas (hydrogen gas or the like) in the case 40 passes through the holes of the porous body portion 50 and the voids 70 and is discharged to the outside of the fuel cell 100. Is done. Therefore, an increase in the pressure in the case 40 is suppressed. Further, as described above, the porous body portion 50 is disposed in the corner portion 42b, that is, is disposed so as to cover the void 70 formed in the corner portion 42b. It is possible to prevent an object having a diameter larger than the diameter from entering the case 40 from the outside. Examples of such objects include various screws, wire harnesses, and fingers of maintenance workers. Similarly, even in the vicinity of the corner portion 42a, even if the first wall portion 41B is destroyed, an increase in pressure in the case 40 can be suppressed, and foreign matter can be prevented from entering the case 40.

  According to the fuel cell 100 having the above configuration, the case 40 includes the first wall portion 41B, the second wall portion 41R that intersects the first wall portion 41B and has higher rigidity than the first wall portion 41B, and the fourth wall portion 41R. Since the wall 41L is included, when the gas generated by the abnormal combustion of the reaction gas in the stacked body 10 leaks from the stacked body 10 and the pressure in the case 40 rises excessively, the first wall is near the intersection. The pressure in the case 40 can be released by intentionally destroying the portion 41B, and the increase in the pressure in the case 40 can be suppressed. Further, even when the first wall portion 41B is destroyed in this way, the porous body portion 50 is disposed at the corner portions 42a and 42b corresponding to the intersecting portions, so that the pressure in the case 40 is released. However, it is possible to prevent a member having a diameter larger than the hole of the porous body portion 50 from entering the case 40.

B. Variations:
B1. Modification 1:
In the above embodiment, the rigidity difference between the first wall portion 41B, the second wall portion 41R, and the fourth wall portion 41L is provided due to the difference in average thickness, but the present invention is not limited to this. For example, the corner portions 42a and 42b of the first wall portion 41B are notched at predetermined intervals along the stacking direction, and the corner portion 42a of the fourth wall portion 41L and the corner portion 42b of the second wall portion 41R are provided on the corner portions 42a and 42b. By not providing such a notch, a difference in rigidity between the first wall portion 41B, the second wall portion 41R, and the fourth wall portion 41L may be provided. In this case, the same effect as that of the above-described embodiment can be obtained by disposing the porous body portion 50 at the location where the cutout is formed in the first wall portion 41B. Also, ribs are provided on the inner surfaces of the corner portion 42a of the fourth wall portion 41L and the corner portion 42b of the second wall portion 41R, and no ribs are provided on the first wall portion 41B. A difference in rigidity between the second wall portion 41R and the fourth wall portion 41L may be provided.

  Further, the first wall portion 41B, the second wall portion 41R, and the fourth wall portion 41L are made different by making the material of the first wall portion 41B different from the material of the second wall portion 41R and the fourth wall portion 41L. A rigidity difference may be provided. For example, the first wall portion 41B may be formed of aluminum, the second wall portion 41R and the fourth wall portion 41L may be formed of iron, or the first wall portion 41B, the second wall portion 41R, and the fourth wall portion. 41L may be made of the same metal member, and the second wall portion 41R and the fourth wall portion 41L may be made of an alloy with another metal to increase the rigidity of the first wall portion 41B. The second wall portion 41R and the fourth wall portion 41L may be hardened so that the rigidity is higher than that of the first wall portion 41B. Even in such a configuration, the same effects as those of the above-described embodiment can be obtained.

B2. Modification 2:
In the said embodiment, although the porous body part 50 was arrange | positioned along the lamination direction from the opening part of the case main-body part 40a to the 3rd wall part 41E, this invention is not limited to this. For example,
After configuring the length of the porous body portion 50 in the stacking direction (X-axis direction) to be short, such a porous body portion 50 may be arranged at predetermined intervals along the stacking direction. Even in such a configuration, the same effects as those of the above-described embodiment can be obtained.

B3. Modification 3:
In the said embodiment, although the cross-sectional shape by the surface parallel to the horizontal surface of the porous body part 50 was substantially rectangular, it could replace with a rectangle and arbitrary shapes, such as a trapezoid and a circle. Even in such a configuration, the same effects as those of the above-described embodiment can be obtained.

B4. Modification 4:
In the above embodiment, the porous body 50 has a triangular prism-like appearance, but it may be a columnar shape instead of the triangular prism shape, or may be a plate shape instead of the columnar shape. For example, you may comprise as an angle member of the cross-sectional L shape provided with many holes. Even in such a configuration, the same effects as those of the above-described embodiment can be obtained.

B5. Modification 5:
In the above embodiment, the thicknesses of the third wall portion 41E, the fourth wall portion 41L, and the fifth wall portion 41T are the same as the thickness t2 of the second wall portion 41R, but the present invention is not limited to this. . For example, the thickness of the fifth wall portion 41T may be set to be the same as the thickness t1 of the first wall portion 41B. In this case, in the case 40, the corner corresponding to the intersection between the fifth wall 41T and the second wall 41R, and the corner corresponding to the intersection between the fifth wall 41T and the fourth wall 41L. By arranging the porous body portion 50 for each, the same effects as in the present embodiment can be obtained.

B6. Modification 6:
In the above embodiment, the first end plate 20a is accommodated in the case 40 (case body 40a), but the present invention is not limited to this. For example, the case lid 40b may be omitted, and the first end plate 20a may have a function as the case lid 40b. Even in such a configuration, the same effects as in the present embodiment can be obtained.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Laminated body 11 ... Single cell 12 ... Terminal plate 13 ... Insulator 20a ... 1st end plate 20b ... 2nd end plate 30 ... Pressure plate 40 ... Case 40a ... Case main-body part 40b ... Case cover part 41B ... 1st Wall part 41E ... 3rd wall part 41L ... 4th wall part 41R ... 2nd wall part 41T ... 5th wall part 42a, 42b ... Corner | angular part 50 ... Porous body part 70 ... Air gap 80 ... Bolt 90 ... Fuel cell stack 100 ... Fuel cell Ar1 ... area

Claims (1)

A fuel cell,
A laminate including a plurality of laminated single cells;
A first wall portion and a second wall portion that intersects the first wall portion and has higher rigidity than the first wall portion;
Inside the case, a porous body part disposed at a corner corresponding to the intersection of the first wall part and the second wall part,
A fuel cell comprising:

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