JP2013101849A - Separator with gasket for fuel cell, and fuel cell stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separator with a gasket for a fuel cell and a fuel cell stack which surely prevent positional deviation of a gasket without causing large distortion of the gasket and a separator even in compression, and achieve improvement of durability of the gasket and prevention of damage of the separator.SOLUTION: In the separator with the gasket for the fuel cell, a gasket 2 is formed on a joint portion 12 including a projecting portion 11 provided on a separator 1, an apex portion 21 of the gasket 2 is provided so as not to overlap with the projecting portion 11 of the separator 1 when viewed from a thickness direction of the separator 1. When the gasket 2 is compressed, a compressive force applied to the apex portion 21 of the gasket 2 is received by the joint portion 12 including no projecting portion 11 of the separator, distortion in the gasket 2 is controlled to be low, and a sealing surface pressure is secured. Accordingly, durability of the gasket 2 can be improved, the gasket 2 is supported by the apex portion 11, and positional deviation of the gasket 2 can be prevented.

Description

  The present invention relates to a fuel cell separator with a gasket and a fuel cell stack.

  Fuel cells are highly reactive because they produce electricity and heat by reacting a fuel gas containing at least hydrogen and an oxidant gas containing at least oxygen, and directly or indirectly convert the chemical energy of the fuel into electrical energy. Power generation efficiency can be obtained.

  A fuel cell has a membrane electrode assembly (MEA) in which an anode and a cathode are formed on both surfaces of an electrolyte membrane, and a flow path for supplying and discharging fuel gas and oxidant gas to the anode and cathode, respectively. It is composed of a stack in which a plurality of single cell modules composed of formed separators are stacked.

  Between the separator and the MEA, or between the separator and the separator, in order to prevent the fuel gas, the oxidant gas, and the cooling water from leaking to the outside or to each other's space, a gasket is disposed in each. Sealed and airtight.

  Moreover, the separator with a gasket in which the gasket is formed integrally with the separator can improve the assemblability of the stack.

  A sectional view of a gasket joint portion of a conventional separator with gasket is shown in FIG. The integrated gasket 200 formed on the separator 100 can be formed on the separator 100 with high precision by molding, but the gasket 200 slides on the surface of the separator 100 during compression, and the sealing performance is reduced. There has been a problem that distortion occurs and the durability of the gasket 200 itself decreases.

  Thus, for example, Patent Document 1 discloses a method in which a protrusion 101 is provided on a separator 100 and a gasket 200 is formed so as to cover the protrusion 101 as shown in FIG. According to this configuration, the protrusions 101 provided on the separator 100 support the gasket 200 and prevent positional displacement, so that the durability of the gasket 200 can be improved.

JP 2001-185174 A

  However, the conventional separator with a gasket for a fuel cell has a structure in which a protrusion is provided on the separator for the purpose of preventing displacement. In this structure, the apex of the gasket overlaps with the protrusion in the cross-sectional direction. In addition, due to the compressive force applied to the apex, a strong stress is generated inside the gasket during compression, and there is a problem that the reliability of the sealing gasket is lowered.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a fuel cell separator with a gasket that reliably prevents the displacement of the gasket and improves the durability of the gasket.

  In order to solve the above-described conventional problems, in the separator with a gasket for a fuel cell of the present invention, the gasket is formed on a joint portion including a convex portion provided on the separator, and the apex portion of the gasket has a thickness of the separator. It is provided so as not to overlap the convex portion of the separator when viewed from the direction.

  The separator with a gasket for a fuel cell of the present invention can improve the durability of the gasket while maintaining the structure for preventing the displacement of the gasket.

1 is a plan configuration diagram of a fuel cell-equipped separator according to Embodiment 1 of the present invention. Cross-sectional configuration diagram of the main parts of the fuel cell separator with gasket The principal part plane and cross-sectional block diagram of the separator with a gasket for fuel cells in Embodiment 2 of this invention The principal part plane and cross-sectional block diagram of the separator with a gasket for fuel cells in Embodiment 3 of this invention Cross sectional configuration diagram of another shape of separator with gasket for fuel cell The principal part plane and cross-sectional block diagram of the separator with a gasket for fuel cells in Embodiment 4 of this invention Cross sectional configuration diagram of another shape of separator with gasket for fuel cell Cross sectional configuration diagram of another shape of separator with gasket for fuel cell The principal part plane and cross-sectional block diagram of the separator with a gasket for fuel cells in Embodiment 5 of this invention Cross-sectional configuration diagram of conventional separator with gasket for fuel cell Cross-sectional configuration diagram of another shape of conventional separator with gasket for fuel cell

  1st invention is a separator with a gasket for fuel cells provided with a separator and the gasket formed in the said separator, The above-mentioned gasket is formed on the joined part including the convex part provided in the above-mentioned separator, The apex portion of the gasket is provided so as not to overlap the convex portion of the separator when viewed from the thickness direction of the separator.

  With this configuration, when the gasket is compressed, the compressive force applied to the apex of the gasket is received at the joint that does not include the convex portion of the separator, and the distortion inside the gasket is kept low, ensuring the seal surface pressure. It is possible to improve the durability.

  In addition, since the gasket is supported by the convex portion, it is possible to prevent the gasket from being displaced, and to ensure the sealing performance and durability of the gasket.

  According to a second invention, in the first invention, the gasket includes a close contact portion including the apex portion that is in close contact with the plate body facing the separator, and a non-contact portion that is not in contact with the plate body facing the separator. The separator is provided with a convex portion so as to overlap the non-contact portion of the gasket as viewed in the thickness direction of the separator.

With this configuration, the convex portion of the separator is not formed under the close contact portion where a large stress is generated inside the gasket, so that the distortion inside the gasket can be further reduced, and the durability of the gasket can be ensured. it can.

  According to a third aspect of the present invention, in the first or second aspect, the joint portion of the separator includes a pair of convex portions, and the gasket has the apex portion positioned between the pair of convex portions. The separator is formed on the joint portion including the pair of convex portions.

  With this configuration, the movement of the apex portion is restricted between the pair of convex portions, and the apex portion can be arranged in the center of the gasket to prevent displacement, thereby improving the sealing performance and durability of the gasket. Can do.

  According to a fourth invention, in any one of the first to third inventions, the joint portion of the separator includes only the convex portion and a flat flat portion.

  With this configuration, the thickness of the separator can be secured to a certain level, and the strength of the separator can be maintained. Therefore, damage to the separator can be suppressed, and the sealing performance and durability of the gasket can be ensured. In particular, when using a separator containing carbon and a resin that easily breaks, the breakage of the separator can be more reliably suppressed.

  According to a fifth invention, in any one of the first to third inventions, the joint portion of the separator includes a recess, and the gasket includes the separator so that the contact portion is on the recess. It is formed on the joint part including the convex part and the concave part.

  With this configuration, the contact area of the joint is increased, the joint strength of the gasket is improved, and the gasket is further prevented from being displaced, so that the durability of the gasket can be further improved.

  In a sixth aspect based on the fifth aspect, the concave portion and the boundary between the concave portion and the separator body are curved surfaces.

  With this configuration, the compressive force that the gasket receives from the boundary between the recess and the separator body can be dispersed, so that the internal stress at the boundary of the gasket can be kept low, and the durability of the gasket is improved. Can do.

  Also, when a gasket is integrally formed with the separator, if a high-viscosity liquid gasket material is used, it is necessary to increase the injection pressure. However, since the concave portion is curved, the injection pressure received by the concave portion is dispersed, and the separator The internal stress in the recess can be kept low, and damage to the separator can be prevented.

  A seventh invention is characterized in that, in the fifth or sixth invention, a plurality of the recesses are arranged along a seal line in which the gasket is formed.

  With this configuration, the contact area between the recess and the gasket is increased, and the bonding strength between the recess and the gasket is improved. Therefore, the gasket is firmly fixed by the separator, and the displacement of the gasket can be further prevented.

  According to an eighth invention, in any one of the first to seventh inventions, the convex portion and a boundary portion between the convex portion and the separator body are curved surfaces.

With this configuration, it is possible to disperse the compressive force that the gasket receives from the convex portion.
The internal stress at the convex portion of the gasket can be kept low, and the durability of the gasket can be improved.

  Also, when a gasket is integrally formed with a separator, if a high-viscosity liquid gasket material is used, it is necessary to increase the injection pressure, but since the boundary between the convex part and the separator body is curved, the boundary part is The injection pressure received is dispersed, the internal stress at the boundary of the separator can be kept low, and the separator can be prevented from being damaged.

  According to a ninth invention, in any one of the first to eighth inventions, a plurality of the convex portions are arranged along a seal line on which the gasket is formed.

  With this configuration, the contact area between the convex portion and the gasket is increased, and the bonding strength between the convex portion and the gasket is improved. Therefore, the gasket is firmly fixed by the separator, and the displacement of the gasket can be further prevented.

  A tenth aspect of the invention is any one of the first to ninth aspects of the invention, comprising a membrane electrode assembly including a pair of electrodes and an electrolyte membrane, and a flow path for supplying and discharging a reaction gas to the membrane electrode assembly. A fuel cell stack in which a plurality of gasket-equipped separators for fuel cells according to the above are stacked.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the same components as those of the above-described embodiments will be denoted by the same reference numerals, and detailed description thereof will be omitted.

(Embodiment 1)
A fuel cell has a membrane electrode assembly (MEA) in which an anode and a cathode are formed on both surfaces of an electrolyte membrane having hydrogen ion conductivity, and a flow for supplying and discharging fuel gas / oxidant gas to the anode and cathode, respectively. It is composed of a stack in which a plurality of single cell modules each composed of a separator having a groove serving as a path are stacked.

  FIG. 1 is a plan view of the separator according to the first embodiment. The separator 1 disposed on the anode and the cathode is made of a conductive material such as carbon or metal, and between the separator 1 and the MEA, or between the separator 1 and another separator, and in the various manifolds 3. In order to prevent the fuel gas, the oxidant gas, and the cooling water from leaking to the outside or to each other's space, the gaskets 2 are arranged and sealed, respectively, so that airtightness is maintained.

  Further, flow paths 4 for supplying (or discharging) fuel gas and oxidant gas are formed on the sides of the separator 1 facing the electrode surfaces of the anode and the cathode, respectively. Examples of the configuration of the flow path 4 include a serpentine-shaped flow path. Further, a cooling medium flow path for supplying (or discharging) a cooling medium for cooling the fuel cell is formed on the side of the separator 1 not directly facing the anode and the cathode. In addition, the gasket 2 can be integrated with the separator 1 to improve the assemblability of the stack.

FIG. 2 is a cross-sectional view of the gasket joint portion in part A of FIG. As shown in FIG. 2, the gasket 2 of the separator with a fuel cell gasket of the first embodiment is formed on the joint 12 including the convex portion 11 provided on the separator 1, and the apex 21 of the gasket is When viewed from the thickness direction of the separator 1, the separator 1 is provided so as not to overlap with the convex portion 11 of the separator 1 so as to be positioned above the joint portion 12. With this configuration, when the gasket 2 is compressed, the compressive force applied to the apex portion 21 of the gasket 2 is received by the joint portion 12 that does not include the convex portion 11 of the separator. Since the surface pressure is ensured, the durability of the gasket 2 can be improved. Furthermore, since the gasket 2 is supported by the convex part 11, the position shift of the gasket 2 can be prevented, and the sealing performance and durability of the gasket 2 can be ensured.

  Further, the convex portion 11 and the first boundary portion 13 between the convex portion 11 and the separator 1 are curved surfaces that are chamfered, and the gasket 2 can disperse the compressive force received from the convex portion 11. It has become. With this configuration, the internal stress in the convex portion 11 of the gasket 2 can be kept low, and the durability of the gasket 2 can be improved. Further, when the gasket 2 is integrally formed with the separator 1, when a high-viscosity liquid gasket material is used, it is necessary to increase the injection pressure. However, the first boundary 13 between the convex portion 11 and the separator 1 is curved. Thus, the injection pressure received by the first boundary portion 13 is dispersed, the internal stress at the first boundary portion 13 of the separator 1 can be kept low, and the separator 1 can be prevented from being damaged.

(Embodiment 2)
The fuel cell separator with gasket of the second embodiment will be described with reference to FIG. FIG. 3 is a cross-sectional configuration diagram of a gasket 2 joint portion of a separator with a gasket for a fuel cell according to Embodiment 2 of the present invention. The gasket 2 includes a close contact portion 22 including the apex portion 21 that is in close contact with the plate body facing the separator 1 and a non-contact portion 23 that is not in contact with the plate body facing the separator 1, and from the thickness direction of the separator 1. As seen, the convex portion 11 is provided on the separator so as to overlap the non-contact portion 23 of the gasket 2. The other points are the same as those in the first embodiment, and the description is omitted.

  In particular, the gasket 2 is formed on the joint portion 12 including the convex portion 11 provided on the separator 1, and the close contact portion 22 including the apex portion 21 overlaps the joint portion 12 not including the convex portion 11 of the separator 1. It is provided as follows. With this configuration, when the gasket 2 is compressed by the plate body facing the separator 1, the compressive force applied to the close contact portion 22 where a large stress is generated inside the gasket 2 is applied to the joint portion 12 that does not include the convex portion 11 of the separator 1. Thus, the internal strain of the gasket 2 can be kept low, and the seal surface pressure can be secured. Furthermore, the height of the entire gasket 2 can be minimized, and the size of the stack in which a plurality of modules are stacked can be reduced, and the durability of the gasket 2 can be improved.

  Here, the plate body facing the separator 1 refers to a member that requires airtightness between the separator 1, such as another separator, MEA, a frame body that holds the MEA, or an end plate or manifold piping.

  Further, since the gasket 2 can be supported by the convex portion 11 formed under the non-contact portion 23 that is not stressed during compression, the gasket 2 can be prevented from being displaced, and a plurality of modules are laminated. However, it is possible to prevent the small displacement of the apex portion 21 of the gasket 2 from being overlapped, and to ensure the sealing property and durability of the gasket 2 without causing a large distortion in the gasket 2 or the separator 1 during compression. Can be prevented from being damaged.

(Embodiment 3)
The fuel cell separator with gasket according to Embodiment 3 will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 is a plan and cross-sectional configuration diagram of the gasket 2 joint portion of the separator with a gasket for a fuel cell in Embodiment 2 of the present invention. The joint portion 12 of the separator 1 includes a pair of convex portions 11a and 11b. The gasket 2 is formed on the joint portion 12 including a pair of convex portions 11a and 11b. And a pair of convex parts 11a and 11b are formed under a pair of non-contact parts 23 of gasket 2, respectively, and apex part 21 does not include convex parts 11a and 11b of separator 1, and a pair of convex parts 11a and 11b It is provided so as to overlap with the joint portion 12 located between the two. The other points are the same as those in the second embodiment, and a description thereof will be omitted.

  The shape of the pair of convex portions 11a and 11b may be a substantially triangular shape as shown in FIG. 5, and the corner portion and the first boundary portion 13 between the convex portions 11a and 11b and the separator 1 are curved surfaces that are rounded. The gasket 2 is configured to be able to disperse the compressive force received from the convex portions 11a and 11b.

  According to the configuration of the third embodiment of the present invention, the movement of the apex portion 21 is restricted between the pair of convex portions 11a and 11b, and the apex portion 21 is disposed at the center of the gasket 2 and also prevents displacement. Therefore, the sealing performance and durability of the gasket 2 can be further improved.

(Embodiment 4)
A separator with a gasket for fuel cell according to Embodiment 4 will be described with reference to FIGS. 6 is a cross-sectional view of a gasket 2 joint portion of a separator with a gasket for a fuel cell according to Embodiment 4 of the present invention. The joint portion 12 of the separator 1 includes a concave portion 14, and the gasket 2 is formed on the convex portions 11 a and 11 b and the joint portion 12 including the concave portion 14. The apex portion 21 of the gasket 2 is provided so as to overlap the concave portion 14 that does not include the convex portions 11 a and 11 b of the separator 1. With these configurations, the contact area of the joint portion 12 is increased, the joint strength of the gasket 2 is improved, and the displacement of the gasket 2 is further prevented, so that the durability of the gasket 2 can be further improved. In these respects, although different from the second embodiment, the configuration is otherwise the same, and the description is omitted. In addition, the shape of the recessed part 14 may be a shape as shown in FIG. 7 or FIG.

  Moreover, the compression force which the gasket 2 receives from the 2nd boundary part 15 of the recessed part 14 and the separator 1 is disperse | distributed by making the 2nd boundary part 15 of the recessed part 14 and the recessed part 14 and the separator 1 of FIG. The internal stress at the second boundary portion 15 of the gasket 2 can be kept low, and the durability of the gasket 2 can be improved.

  Further, when the gasket 2 is integrally formed with the separator 1, when a liquid gasket material having a high viscosity is used, it is necessary to increase the injection pressure. However, when the concave portion 14 is curved, the injection pressure received by the concave portion 14 is reduced. Dispersed, the internal stress in the recess 14 of the separator 1 can be kept low, and damage to the separator 1 can be prevented.

(Embodiment 5)
The fuel cell separator with gasket of Embodiment 5 will be described with reference to FIG. FIG. 9 is a plan view and a cross-sectional configuration diagram of a seal line in which convex portions and concave portions of the separator with a gasket for a fuel cell according to Embodiment 5 of the present invention are formed. Although it differs from Embodiment 4 by the point by which multiple convex parts 11a and 11b and the recessed part 14 are arrange | positioned along the seal line in which the gasket 2 is formed, it is the same structure except it, and description is abbreviate | omitted.

  With this configuration, the contact area between the convex portions 11a and 11b and the concave portion 14 and the gasket is increased, and the bonding strength between the convex portions 11a and 11b and the concave portion 14 and the gasket 2 is improved. The position of the gasket 2 can be further prevented from being fixed.

  In the first to fifth embodiments, an embodiment used for an internal manifold type fuel cell system is shown. However, the present invention is not limited to this and may be applied to an external manifold type fuel cell. Of course it is effective.

  As described above, the fuel cell separator and fuel cell stack of the present invention can be applied to uses such as a fuel cell that handles flammable gas such as hydrogen and water, particularly a stack in which a plurality of modules are stacked.

DESCRIPTION OF SYMBOLS 1 Separator 11, 11a, 11b Convex part 12 Joining part 13 1st boundary part 14 Recessed part 15 2nd boundary part 2 Gasket 21 Vertex part 22 Contact | adherence part 23 Non-contact part

Claims (10)

A separator;
A gasket formed on the separator;
In a separator with a gasket for a fuel cell comprising:
The gasket is formed on a joint including a convex portion provided on the separator,
The apex portion of the gasket is provided so as not to overlap the convex portion of the separator as seen from the thickness direction of the separator.
Separator with gasket for fuel cell. The gasket comprises a close contact portion including the apex portion that is in close contact with the plate body facing the separator, and a non-contact portion that does not contact the plate body facing the separator,
Providing a convex portion on the separator so as to overlap the non-contact portion of the gasket as seen from the thickness direction of the separator,
The separator with a gasket for fuel cells according to claim 1. The separator joint includes a pair of convex portions,
The gasket is formed on the joint portion including the pair of convex portions of the separator so that the apex portion is located between the pair of convex portions.
The separator with a gasket for fuel cells according to claim 1 or 2. The joint portion of the separator consists of only the convex portion and a flat flat portion.
The separator with a gasket for fuel cells as described in any one of Claims 1 thru | or 3. The joining portion of the separator includes a recess.
The gasket is formed on the joint including the convex portion and the concave portion of the separator so that the apex portion is on the concave portion.
The separator with a gasket for fuel cells as described in any one of Claims 1 thru | or 3. The recess and the boundary between the recess and the separator body are curved surfaces.
The separator with a gasket for fuel cells according to claim 5. A plurality of the recesses are arranged along a seal line where the gasket is formed.
The separator with a gasket for fuel cells according to claim 5 or 6. The convex part and the boundary part between the convex part and the separator body are curved surfaces.
The separator with a gasket for fuel cells as described in any one of Claims 1-7. A plurality of the convex portions are arranged along a seal line where the gasket is formed.
The separator with a gasket for fuel cells as described in any one of Claims 1-8. A membrane electrode assembly comprising a pair of electrodes and an electrolyte membrane;
The separator with a gasket for a fuel cell according to any one of claims 1 to 9, further comprising a flow path for supplying and discharging a reaction gas to the membrane electrode assembly.
A fuel cell stack with multiple layers.