JPS58155669A - Reaction-gas supplying and exhausting device provided in fuel cell - Google Patents

Abstract

PURPOSE:To obtain a fuel cell which has a simple structure and can be easily assembled without using any manifolds by making a fuel gas to be supplied and exhausted through a path which penetrates the stack of the fuel cell in such a manner that it is not connected to any air supply grooves. CONSTITUTION:Since the internal space of a case 1 is divided into two spaces by means of partitioning members 10a and 10b (more strictly, by a stack 2 and a heat-insulating material 13 as well), an air gas flows from an air-supply hole 14, which opens into one of the above two spaces, through the air supply grooves 9 of the bipolar plates 4 of the stack 2, and is sent into an air exhaust hole 15 which opens into the other space. On the other hand, a fuel gas is sent into the fuel-gas supply grooves of each bipolar plate 4 from a fuel- gas supply hole 16 through a penetrating hole provided inside the stack 2, and finally, sent back to a fuel-gas exhaust hole 17 after passing from the exhaust hole 18 of a terminal plate 8 through a tube 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel cell that generates electricity using a fuel gas and an oxidizing gas (hereinafter referred to as air gas because air gas is generally used) as a reaction gas. A plurality of bipolar plates each having supply grooves disposed on different surfaces so as to be perpendicular to each other in a non-communicating state, and a plurality of fuel cells each consisting of a fuel electrode, an electrolyte-impregnated matrix, and an air electrode sandwiched between the bipolar plate and the bipolar plate. The present invention relates to a reactant gas supply/discharge device for a fuel cell in which individual fuel cells are stacked to form a fuel cell stack and placed in a case.

In conventional fuel cells of this type, the manifolds for fuel gas supply and discharge and air gas supply and discharge are anastomosed to the side of the fuel cell stack via gaskets. Measures were taken to improve flatness and use highly elastic rubber gaskets, but using a manifold requires special measures to distribute the reaction gas evenly to each cell, align the anastomosis, or seal the mechanism. Therefore, it was desired to adopt a structure that avoids the use of manifolds as much as possible.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a reaction gas supply/discharge device that does not use a manifold and has a simple structure that is easy to assemble.

This object, according to the invention, is to provide a fuel cell of the type mentioned at the outset with a partition that substantially prevents the flow of air between the parallel side walls of the nine gas flow channels of the fuel cell stack and the inner wall of the case. A member is provided to divide the interior space of the case, and air gas is sent from one space to the other space through the air supply groove of each bipolar plate of the fuel cell stack, while the air gas is sent through the supply and exhaust passage passing through the fuel cell stack at the non-fuel position. This is achieved by configuring the system to supply and discharge.

According to a preferred embodiment of the present invention, the partition member is preferably arranged so as to fit into a groove provided in the side wall of the fuel cell stack, so that the partition member also serves as a holding member for the fuel cell stack. The effect is obtained.

According to another preferred embodiment of the present invention, the fuel cell stack may include a heat insulating material that prevents air from flowing between the top of the fuel cell stack and the inner wall of the case.

In this way, an effect can be obtained in which unnecessary bypass of reaction air gas can be eliminated.

Other features and embodiments of the invention will become apparent in the detailed description of the invention that follows.

Figures W and X are partially cutaway perspective views of an embodiment of the present invention, and are for explaining the principle structure of the present invention.

In FIG. 1, l indicates a case, which in the embodiment has a substantially rectangular parallelepiped shape. Case I is shown cut away at the notched portion for the purpose of explaining its interior. The name is a fuel cell stack (hereinafter simply referred to as a stack), which is placed on a pedestal 3 of a case 1, and includes a fuel electrode sandwiched between a bipolar plate 4 and a 2-plate, an electrolyte-impregnated i-trix, and an air It is composed of a plurality of stacked fuel cells 6 each consisting of a sandwich body 5 as an electrode.More strictly speaking, the fuel cell consists of the lower surface of i bipolar plates, the sandwich body 5, and another bipolar plate. It functions as a cell with the top surface of the cell.

The fuel cell stack 7 includes an insulating plate 7 at the bottom and an end plate 8 at the top, and the end plate 8 and the frame 7 are fixed with bolts (not shown) in a stacked state. It has become. Reference numeral 9 denotes air supply grooves provided on the upper surface of the plate. Although FIG. 1 shows four grooves per plate for simplicity, there are actually a large number of grooves.

10a and 10b are partition members that are a feature of the present invention, and are made of an insulating material and are provided between the side wall parallel to the air supply #$9, which is the air gas flow path in the stack name, and the case inner wall 11. . Reference numeral 12 denotes a holding member having a U-shaped cross section, which is fixed to the case l and holds the partition member 10a. Partition member 1Obf
(A corresponding holding member is not shown. 13 is a heat insulating material, which is filled between the top of the stack l and the upper inner wall of the case l, and serves to prevent air flow. 14 is an air gas supply. 15 is an air gas discharge port, 16 is a fuel gas supply port, and 17 is a fuel gas discharge port.

As is clear from the configuration shown in FIG. 1, the internal space of the case l is divided into two spaces by the partition members 10a and lOb (more precisely, by the stack l and the heat insulating material 13), so air gas flows from one side to the other. The air is sent from the air supply port 14 opened to the other space through the air supply groove 9 of the bipolar plate 4 of the stack 1 to the air discharge port 15 opened to the other space.

On the other hand, the fuel gas is sent from the fuel gas supply port 16 to the fuel gas supply groove of each bipolar plate through the through hole provided inside the stack, and is finally partially broken off from the discharge port 18 of the end plate 8. The fuel gas is returned to the fuel gas outlet 17 via a pipe 19 shown in FIG.

This fuel gas supply and discharge mechanism is shown in the exploded view of the main parts of the stack shown in FIG.

In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals. The end plate 8 has holes 8a and 8b into which the partition members 10a and 10b fit, and holes 8c and 8 into which the holding member 12 fits.
d is cut off. Mata no (Iborabrate 4.4
Also, the partition member lOb bites into the insulating plate 7 #14
b, 10b is cut off. The groove 4a and the like for the partition member 10a are not shown here.

21 is a fuel electrode, 22 is an electrolyte-impregnated matrix, 23
are air electrodes and these are two bipolar plates 4.
4 to form a fuel cell 6.

Reference numeral 24 denotes a current collector plate, and a corresponding one is provided under the end plate 8 with an insulating plate interposed therebetween, but illustration thereof is omitted in FIG. 1 mainly to explain the fuel gas supply/discharge mechanism.

The fuel gas is supplied from the fuel gas supply port 16 to the through hole 7 of the insulating plate 7 in FIG. The fuel gas supply #I of each bipolar plate 4 is fed through each hole forming a hole.
25.

FIG. 3 shows the bipolar plate 4 in the position shown in FIG. At the other end, it reaches the non-penetrating hole 26, makes a U-turn, returns again via another fuel gas supply #127, and returns to the through-hole 4d.
reach. This flow of fuel gas is performed for each bipolar plate, and finally reaches the discharge portion 8e of the end plate 8 in FIG.
from the outlet 18 to the pipe 19, a portion of which is shown in FIG.
The fuel gas is discharged from the fuel gas outlet 17 through the fuel gas.

In this way, in the present invention, the fuel gas is supplied and discharged through the supply and discharge passage that penetrates the inside of the stack l at a position that does not communicate with the air supply groove, so that the fuel gas is supplied and discharged through the supply and discharge passage that does not communicate with the air supply groove. Moreover, since the internal space of the case itself, which has little pressure loss, is utilized as the air supply/discharge space, there is also the advantage that there is no need for supply/discharge using a manifold.

In addition, when assembling, the top of the case l can be opened, and a stack can be easily formed by simply stacking the insulating plates 7j, current collecting plates 24, etc. from the bottom using the partition plate 10a and the fob as guide plates. This allows for a simple and easy-to-assemble structure.

Further, although the fuel cell needs to be operated at a relatively high temperature, providing the heat insulating material 13 for blocking the flow of air gas has the effect of reducing the loss of generated heat.

Note that various modifications can be made to the embodiments described above within the scope of the technical idea of the present invention.

For example, the fuel gas supply route #! In Figure 3, the non-through hole 26
Although the structure is such that each bipolar plate returns in a closed loop, it is also possible to make a U-turn structure as a whole by penetrating the entire inside of the stack like the through hole 4C.

In addition, since the fuel gas supply path (in terms of fuel gas supply path) may be a through hole penetrating the inside of the stack, the flow differs from the illustrated configuration.
? It is also within the scope of the present invention to configure.

As mentioned above, various modifications can be made to the structure of the partition member, such as using a member having a width in the depth direction instead of a plate shape, or making the inner wall of the case protrude inward to perform a partitioning effect.

Although the present invention is suitable for use in phosphoric acid type fuel cells that use hydrogen gas and air gas, it is also applicable to other types of fuel cells as long as they are of the type described above. be.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention. FIG. 2 is a developed view of the main part thereof. FIGS. 3A and 3B are a perspective view 2 and a mirror view thereof of a bipolar plate. 1... Case, 2... Fuel cell stack, 4... Bipolar plate, 6... Fuel cell, 10a,
10b...T 1st 7zi

Claims (1)

[Claims] l) A bipolar plate in which grooves for supplying air gas and fuel gas are disposed on different surfaces so as to be perpendicular to each other in a non-communicating state, and a fuel electrode and an electrolyzer sandwiched between the bipolar plates. Liquid impregnation! In a fuel cell, a fuel cell stack is formed by stacking several fuel cells each consisting of Trix and an air electrode, and this stack is placed inside a case.
A partition member that substantially prevents air flow is provided between the side wall parallel to the gas flow path of the fuel cell stack and the inner wall of the case to divide the space inside the case into two, allowing the air gas to flow from one space to the fuel. The air supply groove of each bipolar plate of the cell stack is fed into the other space, while the fuel gas is supplied and discharged through a supply/discharge passage that penetrates the inside of the fuel cell stack at a position that does not communicate with the air supply groove. A reaction gas supply and discharge device for a fuel cell characterized by: 2. The device according to claim 1, characterized in that the partition member is cut into a groove provided on the I* side wall of the fuel cell stack so as to serve also as a holding member for the fuel cell stack. Fuel cell reaction gas supply and exhaust system. 3) A reactant gas supply/discharge device for a fuel cell in the apparatus according to claim 1, wherein the fuel cell stack has a heat insulating material that prevents air flow between the top of the fuel cell stack and the inner wall of the case. .