JPS6240831B2 - - Google Patents

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 plates. The present invention relates to a reactant gas supply/discharge device for a fuel cell in which 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, and in order to prevent reaction gas leakage as much as possible, 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 member that substantially prevents the flow of air between the side wall parallel to the air gas flow path of the fuel cell stack and the inner wall of the case. The interior space of the case is divided into two parts, and air gas is sent from one space to the other space through the air supply grooves of each bipolar plate of the fuel cell stack, while the fuel gas communicates with the air supply grooves inside the fuel cell stack. This is achieved by configuring the system to supply and discharge water through a supply and discharge path that penetrates the water at locations where the water is not in use. 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. Effects can be obtained. According to another preferred embodiment of the invention, the fuel cell stack may include a heat insulator that prevents air flow between the top of the 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 following description of embodiments of the invention. FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, and is for explaining the principle structure of the present invention. In FIG. 1, reference numeral 1 denotes a case, which in the embodiment has a substantially rectangular parallelepiped shape. Case 1 is shown cut away at the hatched area for the purpose of explaining its interior. Reference numeral 2 denotes a fuel cell stack (hereinafter simply referred to as the stack), which is placed on the pedestal 3 of the case 1, and includes a sandwich body 5 of a fuel electrode, an electrolyte-impregnated matrix, and an air electrode, which are sandwiched between bipolar plates 4 and 4. It is constructed by stacking a plurality of fuel cells 6 consisting of the following. To be more precise, the fuel cell functions as a cell using the lower surface of one bipolar plate, the above-mentioned sandwich structure, and the upper surface of another bipolar plate. The fuel cell stack 2 is equipped with 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's summery. Reference numeral 9 denotes air supply grooves provided on the upper surface of the bipolar plate. In the figure, four grooves are shown per plate for simplicity, but in reality, a large number of grooves are provided. 10a and 10b are partition members that are a feature of the present invention, and are made of an insulating material and have side walls parallel to the air supply groove 9, which is the air gas flow path of the stack 2 , and the case inner wall 1.
1. A holding member 12 is fixed to the case 1 and has a U-shaped cross section and holds the partition member 10a. A holding member corresponding to the partition member 10b is not shown. A heat insulating material 13 is filled between the top of the stack 2 and the upper inner wall of the case 1, and serves to prevent air from circulating. 14 is an air gas supply port, 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 1 is divided into two spaces by the partition members 10a and 10b (strictly speaking, by the stack 2 and the heat insulating material 13), so air gas flows from one side to the other. The air supply port 14 opened in the space of the stack 2
The air is sent through the air supply groove 9 of the bipolar plate 4 to the air outlet 15 opened in the other space. On the other hand, the fuel gas is sent from the fuel gas supply port 16 through the through hole provided inside the stack to the fuel gas supply groove of each bipolar plate, and is finally partially broken off from the discharge port 18 of the end plate 8. It is returned to the fuel gas outlet 17 via the indicated pipe 19. 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 a partition member 10a,
Grooves 8a and 8b into which 10b bites, and holding member 12
Grooves 8c and 8d are cut into which the material enters. Furthermore, grooves 4b, 10b are cut into the bipolar plates 4, 4 and the insulating plate 7, into which the partition member 10b is inserted. Here, the groove 4 for the partition member 10a
a etc. are not shown. 21 is a fuel electrode, 22 is an electrolyte-impregnated matrix, and 23 is an air electrode, which are sandwiched between two bipolar plates 4, 4 to form a fuel cell 6. 24 is a current collector plate, and the corresponding one is the end plate 8.
Although an insulating plate is provided under the fuel gas, illustration thereof is omitted in order to mainly explain the fuel gas supply and discharge mechanism. The fuel gas is supplied from the fuel gas supply port 16 to the through hole 7c of the insulating plate 7, the hole 24c of the current collecting plate 24, and the through hole 4c of the bipolar plate 4 in one through hole when assembled as a stack, as shown in FIG. The fuel gas is fed through the holes forming the fuel gas and guided to the fuel gas supply grooves 25 of each bipolar plate 4. FIG. 3 shows the bipolar plate 4 in a position A and a mirror image position B shown in FIG. It reaches the hole 26, makes a U-turn, returns again via another fuel gas supply groove 27, and reaches the through hole 4d. This flow of fuel gas is performed for each bipolar plate, and is finally collected at the discharge portion 8e of the end plate 8 in FIG. The fuel gas is discharged from the fuel gas discharge port 17. 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 2 at a position that does not communicate with the air supply groove, so that supply and discharge using a manifold as in the past is not possible. Moreover, since the internal space of the case itself, which has little pressure loss, is utilized as the supply/discharge space, there is also an advantage that supply/discharge using a manifold is not necessary. Also, during assembly, the top of the case 1 can be opened, and the partition plates 10a and 10b are used as guide plates to stack the insulating plates 7, current collector plates 24, etc. from the bottom in this order. A stack can be formed, and the structure can be simple and easy to assemble. In addition, fuel cells need to be operated at relatively high temperatures, but the heat insulating material 13 for preventing the flow of air gas
This has the effect of reducing the loss of generated heat. Note that within the scope of the technical idea of the present invention,
The embodiments described above can be modified in various ways. For example, in FIG. 3, the fuel gas supply path is configured to return to each bipolar plate in a closed loop using non-through holes 26, but this is done by penetrating the entire inside of the stack like the through hole 4c, so that the fuel gas as a whole A U-turn configuration is also possible. In addition, since the fuel gas supply path may essentially be a through hole penetrating the inside of the stack, it is within the scope of the present invention to have a flow path configuration different from that shown in the drawings. Furthermore, the structure of the partition member can be modified in various ways, 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 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 at the beginning. .

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, FIG. 2 is an exploded view of its essential parts, and FIGS. 3A and 3B are a perspective view and a mirror view of a bipolar plate. 1... Case, 2 ... Fuel cell stack, 4...
...Bipolar plate, 6...Fuel cell, 1
0a, 10b...Partition member, 13...Insulating material.

Claims (1)

[Claims] 1. 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 electrolyte sandwiched between the bipolar plates. In a fuel cell in which a plurality of fuel cells each consisting of an impregnated matrix and an air electrode are stacked together to form a fuel cell stack, and this is placed in a case, a side wall parallel to the air gas flow path of the fuel cell stack is A partition member that substantially prevents air flow is provided between the inner wall of the case and the inner space of the case is divided into two parts, and air gas is passed from one space to the other space through the air supply grooves of each bipolar plate of the fuel cell stack. 1. A reaction gas supply and discharge device for a fuel cell, characterized in that fuel gas is supplied and discharged through a supply and discharge passage that penetrates the inside of a fuel cell stack at a position that does not communicate with an air supply groove. 2. In the device according to claim 1,
1. A reactant gas supply and discharge device for a fuel cell, characterized in that a partition member is inserted into a groove provided in the side wall of a fuel cell stack so as to serve also as a holding member for the fuel cell stack. 3. In the device according to claim 1,
1. A reactant gas supply/discharge device for a fuel cell, wherein the fuel cell stack has a heat insulating material for preventing air flow between the top of the fuel cell stack and the inner wall of the case.