Cell stack support structure for fuel cell

Abstract

To provide a cell stack support structure for fuel cell which is capable of maintaining at least G-tolerance and suppressing accumulation of hydrogen in a fuel cell case with an electrical insulation state secured.SOLUTION: A cell stack support structure 10 for fuel cell is provided with a cell stack 16, a buffer material 34, and a mesh tube 38. The buffer material 34 has insulation property and is filled in a gap 32 between the cell stack 16 and a fuel cell case 12. Thus, G-tolerance can be maintained in the cell stack 16, and the buffer material 34 having insulation property can be maintain an electric insulation state in the cell stack 16. The mesh tube 38 can ventilate hydrogen and is connected to a gap part 36 for ventilation that can be communicated with an outside the fuel cell case 12. Thus, hydrogen leaked from the cell stack 16 can be discharged to the outside of the fuel cell case 12 via the mesh tube 38 and the gap part 36, and accumulation of hydrogen inside the fuel cell case 12 is suppressed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cell stack support structure for a fuel cell. [Background technology]

[0002] The following Patent Document 1 discloses a technology in which thin plate fastening (tension) plates are spanned between a pair of end plates arranged at both ends of a stack constituting a fuel cell in the stacking direction above and below the pair of end plates, and a resin cushioning material is provided on the inside of the thin plate fastening plates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-203670 A Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, fuel cell systems are expanding beyond automobiles to a wide range of mobility, and as a result, the required G-force resistance performance is increasing. Meanwhile, fuel cell stacks are high-voltage components, so they must maintain electrical insulation by stacking more than 300 cells and compressing them while floating inside the fuel cell case. In addition, hydrogen permeation occurs from the cell stack, and ventilation performance must be maintained between the cell stack and the fuel cell case in accordance with hydrogen safety regulations.

[0005] In consideration of the above, the present invention aims to provide a cell stack support structure for a fuel cell that can suppress the accumulation of hydrogen in a fuel cell case while maintaining at least G-force resistance and ensuring electrical insulation. [Means for solving the problem]

[0006] The cell stack support structure for a fuel cell according to the invention described in claim 1 comprises a cell stack supported against a fuel cell case with a gap provided between the cell stack and the fuel cell case, a cushioning material filled in the gap and having insulating properties and capable of absorbing shock, and a plurality of mesh tubes provided on the surface of the cell stack and connected to ventilation gaps that allow hydrogen ventilation and can communicate with the outside of the fuel cell case, and the spacing Y between adjacent mesh tubes is set to be smaller than the outer diameter dimension X of the mesh tubes.

[0007] The fuel cell stack support structure according to the invention described in claim 1 includes a cell stack, a cushioning material, and a mesh tube. The cell stack is supported by the fuel cell case with a gap between the cell stack and the fuel cell case. The cushioning material is filled in the gap between the cell stack and the fuel cell case, has insulating properties, and is capable of absorbing shock.

[0008] In this way, by providing a cushioning material between the cell stack and the fuel cell case, shocks input to the cell stack can be absorbed by the cushioning material, making it possible for the cell stack to maintain its G-force resistance. Furthermore, because the cushioning material has insulating properties, it is possible for the cell stack to maintain an electrically insulated state, ensuring the safety of high-voltage components.

[0009] Furthermore, in the present invention, a plurality of mesh tubes are provided on the surface of the cell stack. The mesh tubes are capable of ventilating hydrogen and are connected to a ventilation gap that can communicate with the outside of the fuel cell case. Therefore, hydrogen leaked from the cell stack flows into the mesh tubes and can be discharged to the outside of the fuel cell case through the ventilation gap. This makes it possible in the present invention to suppress the accumulation of hydrogen in the fuel cell case.

[0010] Incidentally, as a comparative example, when the distance Y between adjacent mesh tubes is wider than the outer diameter dimension X of the mesh tube (Y>X), hydrogen leaked from the cell stack may flow out to the buffer material side through the space between the adjacent mesh tubes arranged adjacent to each other and accumulate in the buffer material.

[0011] On the other hand, in the present invention, the distance Y between adjacent mesh tubes is set to be smaller than the outer diameter dimension X of the mesh tube (Y<X). Therefore, the distance between adjacent mesh tubes arranged adjacent to each other can be made narrower than in the comparative example.

[0012] As a result, it becomes possible to suppress the outflow of hydrogen leaked from the cell stack to the buffer material side. Therefore, in the present invention, it is possible to prevent the accumulation of hydrogen in the buffer material while suppressing costs, and it is possible to comply with hydrogen safety regulations.

[0013] Here, the "distance Y between mesh tubes" is the gap provided between adjacent mesh tubes when the cell stack is viewed from the outside.

Effect of the Invention

[0014] As described above, the fuel cell stack support structure according to the present invention can suppress the accumulation of hydrogen in the fuel cell case while maintaining at least the G resistance performance and ensuring the electrical insulation state.

Brief Description of the Drawings

[0015] [Figure 1] It is a schematic cross-sectional view when the fuel cell case constituting a part of the fuel cell stack support structure according to the present embodiment is cut along the longitudinal direction of the fuel cell case. [Diagram 2] (A) is a schematic cross-sectional view when cut along the line A-A' shown in FIG. 1, and (B) is a partially enlarged cross-sectional view obtained by enlarging a part of FIG. 2(A). [Diagram 3]1. FIG. 4 is a cross-sectional view corresponding to FIG. 1, showing a modified example of a cell stack support structure for a fuel cell according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a fuel cell stack support structure according to an embodiment of the present invention will be described with reference to the drawings.

[0017] (Configuration of cell stack support structure for fuel cells) First, the configuration of a cell stack support structure for a fuel cell according to an embodiment of the present invention will be described.

[0018] Fig. 1 shows a schematic cross-sectional view of a fuel cell case 12 (described later) constituting a part of a cell stack support structure 10 for a fuel cell according to this embodiment, cut along the longitudinal direction of the fuel cell case 12. As shown in Fig. 1, in this embodiment, the cell stack support structure 10 for a fuel cell includes a cell stack 16, and this cell stack 16 corresponds to a so-called fuel cell.

[0019] The cell stack 16 can be accommodated in a fuel cell case 12 having a substantially box-like shape, and is configured such that a plurality of plate-like fuel cell cells 14 are stacked along the longitudinal direction of the fuel cell case 12. End plates 18, 20 are provided at both longitudinal ends of the cell stack 16. In this embodiment, for example, the end plate 18 is set to be substantially the same size as the outer dimensions of the cells 14. Meanwhile, the end plate 20 is set to be slightly larger than the outer dimensions of the cells 14.

[0020] A rectangular hole 22 is formed in the side wall 12A of the fuel cell case 12 facing the end plate 18. For example, a rectangular rib 24 is erected from the inner edge of the rectangular hole 22 toward the outside of the fuel cell case 12, and a ventilation membrane 26 is provided on the tip surface of the rectangular rib 24. Through this ventilation membrane 26, the inside of the fuel cell case 12 can communicate with the outside air.

[0021] Support members 28, 30 are provided on the upper and lower sides, respectively, of the rectangular hole 22. The support members 28, 30 have, for example, a rectangular cylindrical shape and are disposed substantially horizontally within the fuel cell case 12. One end of the support members 28, 30 is fastened and fixed to the side wall 12A of the fuel cell case 12, and the other end of the support members 28, 30 is fastened and fixed to the end plate 18 of the cell stack 16.

[0022] In this manner, with the cell stack 16 supported by the support members 28, the cell stack 16 is set to be in a floating state relative to the fuel cell case 12, as shown in Fig. 2(A). Gaps 32 are provided between the upper, lower and lateral sides of the cell stack 16 and the fuel cell case 12, and the gaps 32 are filled with cushioning materials 34. Fig. 2(A) is a schematic cross-sectional view taken along line A-A' shown in Fig. 1.

[0023] The cushioning material 34 is made of foamed resin, rubber, or the like, has insulating properties and is capable of absorbing shock input to the cell stack 16. As shown in Fig. 1, no cushioning material 34 is provided between the rectangular hole 22 and the end plate 18, and instead, a gap 36 is provided for ventilation, and in the gap 36, an end face 34A of the cushioning material 34 forms a wall that constitutes the gap 36.

[0024] Here, in this embodiment, mesh tubes 38, 40 are attached to the surface 16A of the cell stack 16 along the longitudinal direction of the cell stack 16 via double-sided tape, adhesive, or the like. One end of the mesh tube 38 is attached to the upper end of the end plate 20, and the other end of the mesh tube 38 is disposed in the gap 36. Also, one end of the mesh tube 40 is disposed in the gap 36, and the other end of the mesh tube 40 is attached to the lower end of the end plate 20. Nothing is filled inside the mesh tubes 38, 40, and the insides of the mesh tubes 38, 40 are each connected to the gap 36.

[0025] Also, as shown in FIG. 2(A), a plurality of mesh tubes 38 are provided, for example, along the width direction of the cell stack 16. In these plurality of mesh tubes 38, as shown in FIG. 2(B), the interval Y between adjacent mesh tubes 38 arranged adjacent to each other is set to be smaller than the outer diameter dimension X of the mesh tube 38 (Y < X).

[0026] (Function and Effect of Fuel Cell) Next, the function and effect of a fuel cell to which the cell stack support structure for a fuel cell according to the embodiment of the present invention is applied will be described.

[0027] As shown in FIG. 1, in the present embodiment, the cell stack support structure 10 for a fuel cell includes a cell stack 16, a buffer material 34, and a mesh tube 38. The cell stack 16 is supported with respect to the fuel cell case 12 with a gap 32 provided between the fuel cell case 12 by support members 28 and 30. Further, the buffer material 34 is filled in the gaps 32 provided between the upper side, the lower side, and the side of the cell stack 16 and the fuel cell case 12, respectively. Furthermore, the buffer material 34 has insulating properties and is capable of absorbing impact.

[0028] Thus, in the present embodiment, by providing the buffer material 34 between the cell stack 16 and the fuel cell case 12, the impact input to the cell stack 16 can be absorbed by the buffer material 34. Thereby, in the present embodiment, it becomes possible to maintain the G tolerance performance in the cell stack 16. Also, in the present embodiment, since the buffer material 34 has insulating properties, it becomes possible to maintain an electrically insulated state in the cell stack 16, and safety in high-voltage components can be ensured.

[0029] Further, in the present embodiment, as shown in FIG. 2(A), a plurality of mesh tubes 38 and 40 are provided on the surface of the cell stack 16 along the longitudinal direction of the cell stack 16. The mesh tubes 38 and 40 are capable of hydrogen ventilation and are connected to a ventilation gap 36 that can communicate with the outside of the fuel cell case 12. The gap 36 communicates with the rectangular hole 22 and can communicate with the outside air through a ventilation film 26 provided on the tip surface of a rectangular rib 24 standing from the rectangular hole 22.

[0030] Here, the gas in the mesh tubes 38 and 40 flows (diffuses) through the mesh tubes 38 and 40 with the pressure difference, temperature difference, and concentration difference as the driving forces. On the other hand, since the gap 36 communicates with the outside air, the hydrogen concentration is always kept at a low level. Therefore, in the present embodiment, when the hydrogen leaked from the cell stack 16 flows into the mesh tube 38, it can be discharged to the outside of the fuel cell case 12 through the gap 36 with a low hydrogen concentration. Thereby, in the present embodiment, it is possible to suppress the accumulation of hydrogen in the fuel cell case 12.

[0031] Furthermore, the pressure difference or temperature difference between the inside and outside of the fuel cell case 12 always occurs during the operation of the fuel cell system. The driving force for flowing the gas due to this pressure difference or temperature difference is even greater than the driving force due to the concentration difference. Therefore, during the operation of the fuel cell system, it is possible to further improve the hydrogen ventilation performance in the fuel cell case 12. And since the ventilation amount in the mesh tubes 38 and 40 is larger than the amount of permeated hydrogen flowing into the mesh tubes 38 and 40, there is almost no possibility that hydrogen stays in the mesh tubes 38 and 40.

[0032] On the other hand, in the present embodiment, as shown in FIG. 2(B), the interval Y between adjacent mesh tubes 38 is set to be smaller than the outer diameter dimension X of the mesh tube 38 (Y < X). Although not shown in FIG. 2(B), the mesh tube 40 is the same as the mesh tube 38.

[0033] As a comparative example, although not shown in the drawings, when the distance Y between adjacent mesh tubes 38 is wider than the outer diameter dimension X of the mesh tube 38 (Y>X), hydrogen leaked from the cell stack 16 may flow out through the space between the adjacent mesh tubes 38 arranged side by side and accumulate in the buffer material 34.

[0034] On the other hand, in the present embodiment, as described above, the distance Y between adjacent mesh tubes 38 is set to be smaller than the outer diameter dimension X of the mesh tube 38 (Y<X). Therefore, in the present embodiment, the distance between adjacent mesh tubes 38 can be made narrower than in the comparative example.

[0035] As a result, it is possible to suppress the outflow of hydrogen leaked from the cell stack 16 to the buffer material 34 side. Therefore, in the present embodiment, it is possible to prevent the accumulation of hydrogen in the buffer material 34 while suppressing costs, and comply with hydrogen safety regulations.

[0036] From the above, in the cell stack 16 in the present embodiment, it is possible to suppress the accumulation of hydrogen in the fuel cell case 12 while maintaining at least the G resistance performance and ensuring the electrical insulation state.

[0037] Further, in the present embodiment, since the buffer material 34 is filled above, below, and on the side of the cell stack 16, respectively, the G resistance performance is dramatically improved as compared with the prior art of Patent Document 1 described in the background art section. Furthermore, in the present embodiment, since there is no change in the basic structure of the fuel cell case 12 and the cell stack 16, problems such as weight increase and size increase do not occur.

[0038] In the present embodiment, although the example in which the mesh tubes 38 and 40 are provided between the cell stack 16 and the buffer material 34 as shown in FIG. 1 has been described, the present invention is not limited thereto.

[0039] 3, mesh tubes 42, 44 may be provided between the cell stack 16 and the buffer material 34, as well as between the buffer material 34 and the fuel cell case 12. In the case of severe G-force resistance conditions, it becomes necessary to increase the thickness of the buffer material 34. In this case, if hydrogen that has permeated into the buffer material 34 goes to the back side of the buffer material 34, it may not be possible to collect the hydrogen using only the mesh tubes 38, 40 provided on the surface of the cell stack 16.

[0040] However, by providing mesh tubes 38, 40 between the cell stack 16 and the cushioning material 34 and mesh tubes 42, 44 between the cushioning material 34 and the fuel cell case 12, hydrogen that flows out to the cushioning material 34 side through between adjacent mesh tubes 38 (or mesh tubes 40) flows into the mesh tube 42 (or mesh tube 44). This allows hydrogen to be discharged to the outside of the fuel cell case 12 through the gap 36. Therefore, in this embodiment, it is possible to prevent hydrogen from accumulating in the cushioning material 34, and further suppress the accumulation of hydrogen in the fuel cell case 12.

[0041] Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment may be appropriately combined with various modified examples, and the present invention may of course be embodied in various forms without departing from the gist of the present invention. [Explanation of symbols]

[0042] 10. Fuel cell stack support structure 12 Fuel cell case (case) 16 Cell Stack 16A surface 32 Gap 34 Cushioning material 36 Cavity 38 Mesh Tube 40 mesh tube 42 Mesh Tube 44 Mesh Tube

Claims

[Claim 1] a cell stack supported relative to the fuel cell case with a gap provided between the cell stack and the fuel cell case; A shock-absorbing material that is filled in the gap and has insulating properties and is capable of absorbing shock; a plurality of mesh tubes provided on a surface of the cell stack, the mesh tubes being connected to a ventilation gap that allows hydrogen ventilation and can communicate with the outside of the fuel cell case; Equipped with A cell stack support structure for a fuel cell, wherein the interval Y between adjacently arranged mesh tubes is set to be smaller than the outer diameter dimension X of the mesh tubes.

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