JP4890843B2 - Fuel cell stack and fuel cell stack manufacturing method - Google Patents

Description

  The present invention relates to a fuel cell stack and a method for manufacturing a fuel cell stack.

As this kind of conventional fuel cell stack, for example, Japanese Patent Application No. 2004-155202 filed by the present applicant has been cited. In this fuel cell stack, a cell support plate sealed by supporting and fixing the lower end of the cell is engaged with a step on the manifold body and sealed.
In this fuel cell stack, the bonding area is increased by the stepped portion, so that the bonding strength can be improved and the leakage of gas in the manifold can be prevented.

However, the fuel cell stack has the following problems.
(1) When both the cell support plate and the manifold main body are metal, particularly when the manifold main body is enlarged, there is a possibility that a sealing failure may occur due to deformation due to thermal expansion. In the case of a cell support plate with a cell-shaped hole, insulation between cells becomes a problem.
(2) When the cell support plate is non-metallic (glass) and the manifold main body is metal, when the manifold main body is enlarged, the deformation amount of the manifold main body is increased, and a sealing failure with the cell support plate is likely to occur.
(3) When the cell support plate and the manifold body are both non-metallic (glass), when the manifold is enlarged, strength reduction and deformation at high temperatures become problems.

  Therefore, there is a demand for a manifold structure that does not cause seal failure or deformation even when the manifold is enlarged.

  In view of the above situation, the present invention provides a fuel cell stack that can reinforce a ceramic gas manifold and can prevent damage and poor sealing even when the ceramic gas manifold is enlarged, and a method for manufacturing the fuel cell stack. Objective.

In order to solve the above problems, the present invention provides the following configurations.
According to the first aspect of the present invention, a plurality of fuel cells having gas flow paths in the axial length direction are arranged at predetermined intervals on the top plate, and one end of the fuel cell in the axial length direction is arranged on the top plate. A hollow ceramic gas manifold joined to a plate;
A gas supply pipe is joined to one side, and one outer side of the ceramic gas manifold is joined to an inner surface of the one side to which the gas supply pipe is joined, and the other outer side of the ceramic gas manifold And / or a metal or alloy supporting member that supports the bottom portion via a heat-resistant cushioning material, and provides a fuel cell stack.

The invention according to claim 2 is characterized in that the ceramic gas manifold is a top plate that is a cell support plate for arranging and joining the plurality of fuel cells.
The fuel cell stack according to claim 1, further comprising: a container-shaped gas manifold main body having an upper surface opened to form an opening, and the top plate being airtightly joined to the opening. It is to provide.

  The invention according to claim 3 is the fuel cell according to claim 1 or 2, wherein the support member is formed in a container shape having an open upper surface, and the ceramic gas manifold is accommodated in the support member. A cell stack is provided.

  According to a fourth aspect of the present invention, there is provided the fuel cell stack according to the third aspect, wherein a heat-resistant cushioning material is interposed in a gap portion between the support member and the ceramic gas manifold that is not joined. Is.

The invention according to claim 5 excludes a step of joining a metal pipe serving as a gas supply pipe to one side part of a metal or alloy container having an open upper surface, and a side part through which the metal pipe passes. Placing a ceramic slurry and an outer mold which is a heat-resistant cushioning material having poor wettability on the other inner side and inner bottom of the container; and separating the ceramic mold and the inner mold having poor wettability by being spaced apart from the outer mold by a predetermined distance. Placing the ceramic slurry into the gap between the outer mold and the inner mold and firing, and after firing, removing the inner mold to produce a manifold body having an open top surface;
A step of placing the ceramic main body on the top of the manifold main body with a cell support plate joined to one end in the axial direction of a plurality of fuel cells through a ceramic slurry, firing the ceramic slurry, and the manifold main body And a step of joining the cell support plate to the upper part. A method of manufacturing a fuel cell stack is provided.

According to the first aspect of the present invention, since one outer side portion of the ceramic gas manifold is joined to the inner side surface of the one side portion to which the gas supply pipe of the support member is joined, the joining area is small. In addition, since the support member supports the other outer side and / or bottom of the ceramic gas manifold via the heat-resistant cushioning material, the ceramic gas manifold can be reinforced by the support member, and even when the manifold is enlarged, the ceramic gas manifold can be reinforced. The deformation resulting from the difference in thermal expansion between the gas manifold and the support member can be prevented, the ceramic gas manifold can be prevented from being damaged and the sealing failure can be prevented, and the ceramic gas manifold can be reliably supported. Further, since the gas supply pipe is joined to the support member, vibration due to the gas supply pipe can be suppressed, and damage to the ceramic gas manifold and seal failure due to vibration of the gas supply pipe can be prevented.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the ceramic gas manifold includes a top plate that is a cell support plate and a container shape in which the top plate is airtightly joined to the opening on the upper surface. The gas manifold main body has a simple structure and is easy to manufacture.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, the ceramic gas manifold is accommodated in the container-shaped support member having the upper surface opening. It is protected and reinforced in a large area by the member.

  According to the invention described in claim 4, in addition to the effect of the invention described in claim 3, the ceramic gas manifold can be protected by the heat-resistant cushioning material having a large area, and the ceramic gas manifold, the support member, The deformation caused by the difference in thermal expansion of the ceramic gas manifold can be prevented, and the ceramic gas manifold can be prevented from being damaged and poorly sealed.

According to the fifth aspect of the present invention, it is possible to easily manufacture a manifold body that is bonded to one side portion of a container serving as a support member and supported on the other inner side and inner bottom of the container via a heat-resistant cushioning material. The joint area between the container and the manifold body can be reduced, and deformation caused by the difference in thermal expansion between the container and the manifold body can be prevented by the heat-resistant cushioning material. Can be prevented, and the manifold body can be reliably supported in a metal or alloy container.
In addition, since the cell support plate is joined to the upper part of the manifold body, manufacturing is also easy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings showing examples.
In FIG. 1, reference numeral 1 denotes a fuel cell stack according to the present invention. The fuel cell stack 1 includes a plurality of fuel cells 2, 2... Having gas flow paths (not shown) in the axial direction. A hollow ceramic gas manifold 4 which is arranged on the plate 3 at a predetermined interval and in which one end in the axial direction of the fuel cells 2, 2... The gas supply pipe 5 is joined in a penetrating manner to the side part 7a (right side in the figure), and the outer side part 4a of the ceramic gas manifold 4 is attached to the inner side surface of the one side part 7a to which the gas supply pipe 5 is joined. (The right outer portion in the figure) is joined, and the other outer portion 4b of the ceramic gas manifold 4 {the left outer portion and the front and rear outer portions (not shown) in the drawing} and the bottom portion 4c (in the drawing). Metal or composite that supports the lower bottom surface via the heat-resistant cushioning material 6 It has and a manufacturing of the support member 7.
The gas supply pipe 5 is not necessarily provided so as to penetrate the one side portion 7a of the support member 7. For example, the gas supply pipe 5 is provided so as not to penetrate the one side portion 7a of the support member 7. A through-hole communicating with the gas supply pipe 5 may be provided in the outer side portion 4 a of the gas manifold 4.

  The ceramic gas manifold 4 is a gas manifold made of ceramics including glass ceramics such as crystallized glass, and is a cell support plate that arranges a plurality of fuel cells 2, 2. The plate 3 is provided with an opening 8a having an upper surface opened, and a gas manifold main body 8 having a rectangular parallelepiped container shape, for example, in which the top plate 3 is airtightly joined to the opening 8a.

Further, the support member 7 is formed in, for example, a rectangular parallelepiped container shape having an open upper surface, and is configured so that the ceramic gas manifold 4 is accommodated inside the support member 7.
And the gap part between the said supporting member 7 and the ceramic gas manifold 4, ie, the other outer side part 4b (the left outer side surface and the front and rear outer side surface) of the ceramic gas manifold 4, and the other inner side part 7b ( The heat-resistant cushioning material 6 is interposed in all gaps between the left inner surface and the front and rear inner surfaces) and the inner bottom portion 7c.

  Thus, the operation of the fuel cell stack 1 will be described. The fuel gas supplied from the gas supply pipe 5 flows into the hollow part 4d in the ceramic gas manifold 4, and a plurality of fuels are supplied from the hollow part 4d. It flows into the gas flow paths of the battery cells 2, 2.

  Thus, according to the fuel cell stack 1 of the present invention, the outer side portion 4a of the ceramic gas manifold 4 is joined only to the one side portion 7a to which the gas supply pipe 5 of the support member 7 is joined. And the support member 7 supports the other outer portion 4b and the bottom portion 4c of the ceramic gas manifold 4 via the heat-resistant cushioning material 6, so that the ceramic gas manifold 4 is reinforced by the support member 7. In addition, the heat-resistant cushioning material 6 can prevent deformation caused by a difference in thermal expansion between the ceramic gas manifold 4 and the support member 7, and can prevent damage to the ceramic gas manifold 4 and poor sealing. The ceramic gas manifold 4 can be reliably supported. In particular, when the fuel cell stack 1 is enlarged, the effect is great.

In addition, since the gas supply pipe 5 is joined to the support member 7, vibration due to the gas supply pipe 5 can be suppressed by the support member 7, and damage to the ceramic gas manifold 4 and seal failure due to vibration of the gas supply pipe 5 can be prevented.
Further, the ceramic gas manifold 4 of the fuel cell stack 1 of the present invention includes a top plate 3 as a cell support plate, and a container-shaped gas manifold main body 8 in which the top plate 3 is airtightly joined to the opening 8a on the upper surface. Therefore, it has a simple configuration and is easy to manufacture. It is also possible to produce the ceramic gas manifold 4 by simultaneously molding and firing the manifold body 8 and the top plate 3 in a state where the fuel cells 2, 2,... Are set.

  Furthermore, in the fuel cell stack 1 of the present invention, since the ceramic gas manifold 4 is accommodated in the container-shaped support member 7 having an upper opening, the ceramic gas manifold 4 is protected over a wide area by the container-shaped support member 7. And reinforced.

The fuel cell stack 1 according to the present invention has a gap portion between the support member 7 and the ceramic gas manifold 4, that is, the other outer portion 4 b (left outer portion, front and rear outer portion) and bottom portion of the ceramic gas manifold 4. Since the heat-resistant cushioning material 6 is interposed over a wide area in the gap portion 4c, the ceramic gas manifold 4 can be protected over a wide area by the heat-resistant cushioning material 6, and the ceramic gas manifold 4 and Deformation resulting from a difference in thermal expansion with the support member 7 can be prevented, and damage to the ceramic gas manifold 4 and poor sealing can be prevented.
As the heat resistant buffer material 6, a material that easily absorbs the solvent of the ceramic slurry and has poor wettability can be used. However, in terms of ease of processing and heat resistance, SiO ₂ -based, SiO ₂ -Al ₂ O ₃ A system heat insulating material can be used suitably. As the ceramic slurry, borosilicate glass can be suitably used in terms of heat resistance and compact strength.

In the above description, the gas manifold body 8 has been described as having a rectangular parallelepiped container shape, for example. However, the present invention is not limited thereto, and may be formed in other shapes such as a cylindrical container shape. At that time, the same effect can be expected.
Similarly, although it has been described that the support member 7 is also formed in a rectangular parallelepiped container shape, for example, the present invention is not limited to this, and may be formed in other shapes such as a cylindrical shape. The effect can be expected.

Next, the manufacturing method of the fuel cell stack 1 of the present invention will be described with reference to FIG.
First, a metal pipe serving as a gas supply pipe 5 is joined to one side 7a (right side in the figure) of a support member 7 made of a metal or alloy container having an open top surface (step S1). An outer mold 9 serving as a ceramic slurry and a heat-resistant cushioning material 6 having poor wettability is disposed at a predetermined thickness on the other inner portion 7b and inner bottom portion 7c of the support member 7 excluding the one side portion 7a through which the gas supply pipe 5 passes ( In step S2), in order to produce the manifold body 8, ceramic slurry and the inner mold 10 having poor wettability are arranged at a predetermined interval from the outer mold 9 (step S3), and the ceramic is placed in the gap between the outer mold 9 and the inner mold 10. The rally 11 is poured and fired (step S4), and after firing, the inner mold 10 of the outer mold 9 is removed to produce a manifold body 8 having an open upper surface (step S5).
The ceramic slurry 11 is a ceramic slurry containing a glass slurry such as a crystallized glass slurry.

  On the other hand, the axial ends of the plurality of fuel cells 2, 2... Are placed on the inner bottom 12a of the dish-like mold 12 at a predetermined interval (step S6), and the cell support plate 13 and the mold 12 are placed in the mold 12. The ceramic slurry 14 is poured and fired (step S7), the mold 12 is removed, and the cell support plate 13 in which the axial ends of the plurality of fuel cells 2, 2,... Are joined is produced (step S8).

Then, a cell support plate 13 in which one end in the axial direction of the plurality of fuel cells 2, 2... Is joined to the upper portion of the manifold body 8 is used as a top plate through a ceramic slurry 15 (that is, ceramic on the mounting surface). On the other hand, the ceramic slurry 16 is also poured into the joint surface between the one side portion 7a of the support member 7 and the manifold body 8 (step S10), and the ceramic slurries 15, 16 are applied. And the cell support plate 13 is joined to the upper portion of the manifold body 8 (step S11), and the one side portion 7a of the support member 7 and the manifold body 8 are joined (step S12). Is manufactured (step S13).
The ceramic slurries 14, 15 and 16 are ceramic slurries containing a glass slurry such as a crystallized glass slurry. The slurries 15 and 16 have the same ceramic components as the slurry 14, but have a higher viscosity than the slurry 14. It is adjusted.

  Thus, according to the method for manufacturing the fuel cell stack 1, the fuel cell stack 1 having the above-described effects can be easily manufactured. In particular, the method of manufacturing the fuel cell stack 1 according to the present invention is a method of joining the cell support plate 13 as the top plate 3 to the upper portion of the manifold main body 8 and is therefore extremely easy to manufacture. Further, the joint surface between the manifold body 8 and the support member 7 can be reduced, and other side surfaces and bottom surfaces other than the joint surface of the manifold body 8 are held via the heat-resistant cushioning material 6 which is the outer mold 9. Further, it is possible to prevent the manifold main body 8 from being damaged and the sealing failure at the time of manufacturing.

  In step S10, the ceramic slurry 16 is poured into the joint surface between the support member 7 and the manifold body 8. However, in the steps S4 and S5, the manifold body 8 and the support member 7 can be sufficiently joined. In some cases, step S10 may be omitted.

FIG. 3 shows a modified support member 21 used in place of the support member (7 in FIG. 1) of the fuel cell stack (1 in FIG. 1). The support member 21 has a rectangular parallelepiped frame. A flat plate 23 is provided on one side portion of the frame structure 22 formed in the above, and one end portion of the gas supply pipe 5 is joined to the flat plate 23 in a penetrating manner.
Thus, the ceramic gas manifold 4 is accommodated in the frame structure 22 of the support member 21, one end of the ceramic gas manifold 4 is joined to the flat plate 23, and the contact portion between the ceramic gas manifold 4 and the frame structure 22 is joined. Is provided with a heat-resistant cushioning material 6.
Thus, the same effect as that of the support member 7 can be expected by the support member 21.

  As described above, in the fuel cell stack 1 of the present invention, the support member 7 joins the one side portion 7a joined through the gas supply pipe 5 to the one side portion of the ceramic gas manifold 4, and the ceramic gas Since the other side and / or bottom of the manifold 4 only needs to be held via the heat-resistant cushioning material 6, the support member 7 is not limited to the above-described rectangular parallelepiped container and frame structure 22, and is formed in various shapes. At that time, the same effect can be expected.

It is a front longitudinal cross-sectional view of the fuel cell stack according to the present invention. It is explanatory drawing of the manufacturing method of the fuel cell stack by this invention. It is a perspective view of the supporting member of the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell stack 2 Fuel cell 3 Top plate 4 Ceramic gas manifold 4a One outer side part 4b Other outer side part 4c Bottom part 5 Gas supply pipe 6 Heat resistant buffer material 7,21 Support member 7a One side part 8 Gas manifold main body 8a Opening Part 9 Outer mold 10 Inner mold 11, 15, 16 Ceramic slurry 13 Cell support plate

Claims (5)

A hollow body in which a plurality of fuel cells having gas flow paths in the axial length direction are arranged at predetermined intervals on the top plate, and one end portion in the axial length direction of the fuel cell is joined to the top plate Shaped ceramic gas manifold,
A gas supply pipe is joined to one side, and one outer side of the ceramic gas manifold is joined to an inner surface of the one side to which the gas supply pipe is joined, and the other outer side of the ceramic gas manifold And / or a metal or alloy support member that supports the bottom portion via a heat-resistant buffer material. The ceramic gas manifold is a top plate that is a cell support plate for arranging and joining the plurality of fuel cells.
The fuel cell stack according to claim 1, further comprising: a container-shaped gas manifold main body having a top surface opened to form an opening, and the top plate being airtightly joined to the opening. 3. The fuel cell stack according to claim 1, wherein the support member is formed in a container shape having an open upper surface, and the ceramic gas manifold is accommodated in the support member. The fuel cell stack according to claim 3, wherein a heat-resistant buffer material is interposed in a gap portion between the support member and the ceramic gas manifold that is not joined. A step of penetrating and joining a metal pipe serving as a gas supply pipe to one side of a metal or alloy container having an open upper surface; and the other inner side and inner part of the container excluding the one side through which the metal pipe passes. A step of disposing a ceramic slurry and a heat-resistant cushioning material having poor wettability at the bottom, a step of disposing the ceramic slurry and the inner mold having poor wettability at a predetermined distance from the outer mold, and the outer mold And a step of pouring ceramic slurry into the gap between the inner mold and firing, a step of removing the inner mold after firing and producing a manifold body having an open upper surface,
A step of placing the ceramic main body on the top of the manifold main body with a cell support plate joined to one end in the axial direction of a plurality of fuel cells through a ceramic slurry, firing the ceramic slurry, and the manifold main body And a step of joining the cell support plate to an upper part. A method for producing a fuel cell stack, comprising:

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