JPS60246569A - Fuel cell - Google Patents

Abstract

PURPOSE:To prevent certainly the electric short between a cell main body and a surrounding member in a simple mechanism, so as to decrease the output power loss of the cell and make it easy to set up the cell, by fastening and fixing keep plates on both sides of the cell main body which is laminated of unit cells, as laying electrical insulators between the cell main body and the keep plates. CONSTITUTION:Four manifolds 17A, 17B, 17C, 17D are formed in a keep plate 16. A fuel leading-in pipe 18 is welded to the manifold 17A, and a fuel exhausting pipe 19 is welded to the manifold 17B. An oxidizing agent feeding pipe 20 is welded to the manifold 17C, and an oxidizing agent exhausting pipe 21 is welded to the manifold 17D. The keep plate 16 is constituted in this way, and a ceramic insulator 23 is set between the keep plate 16 and a cell main body 22. Manifolds, which are connected with the manifolds in the keep plate 16 respectively, at the same time, connected with gas flow routes of a separator in the cell main body, are formed in this insulator 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a fuel cell, and more particularly to a fuel cell in which electrical insulation between a cell main body and members around the main body is improved.

[Background of the invention]

1 and 2 show the structure of a conventional fuel cell. In FIG. 1, end plates 3 are arranged at both ends of a battery body 2 in which unit cells including a separator 1 are stacked. The battery body 2 is fastened and fixed to the outside of the cell 3 by a surface plate 5 via an insulating plate 4. In addition, since the fuel inlet pipe 6 and fuel discharge pipe 7 that communicate with each separator 1 in the battery body 2 are usually made of metal, electrical short circuits between the battery body 2 and the fuel inlet pipe 6 and fuel discharge pipe 7 are prevented. In order to prevent this, two insulating tubes 8 made of ceramic are provided in each of the fuel inlet tube 6 and the fuel discharge tube 7. The figure shows the fuel system flow path in particular, but in reality, the oxidizer system flow path also has insulated tubes for the oxidant inlet pipe and the oxidizer discharge pipe, so there are eight in total. Insulated tubes will be used.

However, joining metals and ceramics is difficult, and especially in molten salt fuel cells, where the cell reaction temperature is 6.
When the temperature reaches a high temperature of 50 to 700 C, the bonding strength between the metal tube and the ceramic tube is unreliable, and the thermal cycle and mechanical strength are also insufficient.

Moreover, manufacturing Ceramics in a pipe shape requires high manufacturing costs.

On the other hand, since the fuel cell is operated at high temperatures, the battery main body 2 is covered with a cover 9, and this cover 9 is fixed on a pedestal 10. In this case, for example, the fuel inlet pipe 6, the fuel exhaust pipe 7, and the oxidizer system inlet pipe and exhaust pipe must also be insulated from the pedestal 10. That is, when pulling out the fuel introduction pipe 6 from inside the cover 9 to the outside as shown in FIG.
Backing 1 that frames the flange 11 that is attached to the
2. A bolt backing 14 was used to insulate the bolt 13 that tightens the flange 11, and a flange insulator 15 was further used to insulate the introduction pipe 6 before it reached the gas source.

Such an insulating part must be provided not only in the illustrated fuel introduction pipe 6 but also in the fuel discharge pipe 7, the oxidizer introduction pipe, and the oxidizer discharge pipe. However, providing electrically insulating parts at such a large number of locations increases the risk of electrical short circuits, increases the risk of gas leakage, and has the drawback of poor workability.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel cell that reliably prevents electrical short circuits between a battery main body and members surrounding the main body with a simple device configuration, reduces battery output loss, and is easy to assemble.

[Summary of the invention]

In the present invention, electrical insulation is provided at both ends of the battery body in which unit cells are stacked, since it is technically difficult to insulate the reactant gas flow pipes, and gas leakage and loss of battery output are likely to occur. By tightening and fixing the battery to the outside using a presser plate, electrical insulation between the battery main body, the reaction gas flow path, and other members can be solved at once.

That is, a reaction gas flow path pipe is connected to a holding plate, a gas manifold is provided on the holding plate using its volume, and from this gas manifold, a reaction gas flow path is passed through an electrical insulator into the battery body. It is designed to supply and discharge a reaction gas.

[Embodiments of the invention]

3 to 5 show an embodiment of the present invention. In FIGS. 3 and 4, four manifolds 17A, 17B, 17C and 17D are formed on the holding plate 16. A fuel inlet pipe 18 is connected to the manifold 17A by welding, and a fuel discharge pipe 19 is connected to the manifold 17BK. Further, an oxidizer supply pipe 20 is connected to the manifold 17CK by welding, and an oxidizer discharge pipe 21 is connected to the manifold 17D.

A ceramic insulating plate 23 is disposed between the presser plate 16 having such a structure and the battery body 22. This insulating plate 23 is formed with a manifold that communicates with each manifold provided on the holding plate 16 and also communicates with the gas flow path of the separator in the battery main body.

When assembling the battery, the holding plate 16 is placed on the tightening cylinder 24 with the surface where the manifold is carved as the top surface as shown in FIG. 4, and the ceramic insulation plate 23 is placed on this surface. The battery body 22 is placed on the plate 23. Next, the ceramic insulating plate 23 is placed on the plate 23, and the manifold formed on the ceramic insulating plate 23 and the manifold of the presser plate 16 are surely aligned and communicated with each other. is placed, and the stain pond water body 22 and the holding plate 16 are tightened and fixed by the surface plate 25 and the tightening cylinder 24 as shown in FIG.

The thus obtained molten cell type fuel cell was heated to a cell temperature of 650C and a reactant gas was passed through it to generate electricity.

As a result, the insulation resistance between the battery body and the gas pipe is 800Ω.
, we were able to obtain more than Fuchi, and it was possible to easily insulate the battery body.

〔Effect of the invention〕

According to the present invention, electrical insulation between the battery body and the gas pipe as well as other structural members can be easily ensured.

Furthermore, not only is it easy to connect gas pipes, but they can be handled freely, eliminating concerns about electrical breakdown and gas leaks, and significantly improving work efficiency. Furthermore, by providing a manifold on the holding plate, there is no need to attach an external manifold around the battery, and the overall size of the battery can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a conventional fuel cell, FIG. 2 is a schematic configuration diagram showing an insulating part of a pipe portion of a conventional fuel cell,
FIG. 3 is a plan view of the holding plate in the fuel cell of the present invention, FIG. 4 is a sectional view taken along line A-A in FIG. 3, and FIG. 5 is a schematic configuration diagram showing an example of the fuel cell of the present invention. It is. DESCRIPTION OF SYMBOLS 1... Separator, 2... Battery body, 3... End plate, 4... Insulating plate, 5... Surface plate, 6... Fuel inlet pipe, 7... Fuel discharge pipe, 8... Insulating tube, 9... Cover, 10... Pedestal, 11... Flange, 12...
Backing, 13... Bolt, 14... Bolt backing, 15... Flange insulation part, 16... Holding plate, 17A, 17B, 17C. 17D... Manifold, 18... Fuel introduction pipe, 1
9... Fuel discharge pipe, 20... Oxidizer introduction pipe, 21.
... Oxidizer discharge pipe, 22 ... Battery body, 23 ... Ceramic insulation plate, 24 ... Tighten cylinder 12
5°/° surface plate. Patent applicant Hirobu Yoda, Director of the Agency of Industrial Science and Technology 3

Claims (1)

[Scope of Claims] 1. An electrically insulating sheet metal frame in which a reactant gas supply channel and a reactant gas discharge channel communicating with the inside of the fuel cell main body are formed at both ends of a fuel cell main body in which unit cells are stacked. Tighten and fix the holding plate in which the reaction gas supply flow path and the reaction gas discharge flow path are formed, and connect the reaction gas supply flow path formed in the support plate to a reaction gas supply pipe outside the battery main body. 2. The electrically insulating plate is made of ceramics. 2. The electrically insulating plate is made of ceramics. A fuel cell according to claim 1, characterized in that: