JPH03252061A - Fuel cell - Google Patents

Abstract

PURPOSE:To simplify the structure, to improve the reliability of sealing, to reduce the assembly work, to reduce the number of parts, and to reduce the cost, by erecting plural ribs to communicate the first suction port and the first exhaust port to the first communicating part, in the first electrode, and erecting plural ribs to communicate the second suction port and the second exhaust port to the second communicating part, in the second electrode. CONSTITUTION:In the same surface of one end of the first electrode through which a fluid fuel flows, the first suction port 16 and the first exhaust port 17 at the fluid fuel side are provided, and plural ribs 13a to 13c to communicate the first suction port 16 and the first exhaust port 17 up to the first communicating part 18 are erected in the first electrode. On the other hand, in the same surface of one end of the second electrode through which a fluid oxidizer flows, at the different side from the opening surface of the first suction port 16 and the first exhaust port 17 of the first electrode, the second suction port 26 and the second exhaust port 27 at the fluid oxidizer side are provided, and plural ribs 23a to 23c to communicate the second suction port 26 and the second exhaust port 27 up to the second communicating part 28 are erected in the second electrode. As a result, the structure is simplified, the reliability of sealing is improved, the assembly work is reduce, the number of parts is reduced, and the cost can be reduced.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a fuel cell, and particularly to a structure for disposing a flow groove through which a fluid fuel such as hydrogen and a fluid oxidizer such as oxygen flow. Regarding improvements.

(Prior Art) Fuel cells are conventionally known as devices that directly convert fuel energy into electrical energy.

This fuel cell is shown in FIG.
As shown in FIGS. 6(a) and 6(b), which are planar cross-sectional views of lines, 1 is a ribbed electrode type fuel cell using phosphoric acid as an electrolyte, and the unit cell is a matrix 1 impregnated with phosphoric acid as an electrolyte. A pair of ribbed electrodes 2 made of a carbonaceous agent are arranged with grooves regularly provided in parallel in directions perpendicular to each other, with the unit cells sandwiched between the two. It consists of Here, these grooves form flow paths for fluid fuel and fluid oxidizer, respectively.
There is. When the unit cells are stacked, a separator 3 having electrical conductivity but not gas permeability is sandwiched between each unit cell.

This fuel cell supplies highly flammable hydrogen gas and air oxygen gas, so when considering the safety structure of the device, it is important to consider the gas seal structure and gas seal material that will not cause gas leakage. Leaving only the openings on both sides of the groove of the ribbed electrode 2, each laminated cross section was airtightly sealed with a lulu to form a laminated cell.

By the way, since the ribbed electrode 2 is a porous body having pores with an average diameter of several tens of microns, the above-mentioned seal alone was not able to prevent gas diffusion leakage from both ends.

As an improvement to this sealing method, as shown in FIG. 7, Japanese Patent Application Laid-Open No. 147461/1983 discloses that the ends of the ribbed electrodes 2 are pre-filled with thermoplastic suspension at the ends perpendicular to the groove direction. There is a fuel cell technology in which a thermoplastic resin film 4 is impregnated with a slurry, and then a thermoplastic resin film 4 is attached to an end parallel to the groove direction, and the edge seal portion is formed by heating and press-fitting the film 4 into one piece.

In addition, as another technique, as shown in Fig. 8,
-173464 Publication, a thermoplastic film 6.7 is attached to the end of the ribbed electrode 2 in a direction perpendicular to the groove direction and in the same direction as the groove direction, and a gas, /-
There is a fuel cell technology that has a configuration that

(Problems to be Solved by the Invention) However, since the input and output directions of hydrogen gas and oxygen gas are orthogonal to each other, the gas seal structure is extremely complicated.

For example, in the embodiment shown in FIG. 7, a total of four thermoplastic films 4 as seals are required in the unit cell at different levels, and the ends of the ribbed electrodes 2 must be pre-impregnated with a suspension of thermoplastic resin. should not.

In the embodiment shown in FIG. 8, the thermoplastic film 6 is
．． Since 7 had to be attached, a total of 8 stickers were required for the unit cell. As a result, the structure became complicated, and assembly became difficult, required a large number of man-hours, and was difficult to set the tightening margin.As a result, there were problems such as gas leakage and damage to the structure. .

The present invention solves these problems by providing a fuel cell that has a simple structure, improves seal reliability, reduces assembly work, reduces the number of parts, and reduces costs. It is about providing.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve this object, the present invention employs a pair of fluid fuel and fluid oxidizer flow grooves with an electrolyte-impregnated matrix sandwiched therebetween. In a fuel cell in which a plurality of unit cells are stacked with a separator in between, the unit cells are arranged with ribbed electrodes and output electrical energy under the condition that fluid fuel and fluid oxidizer are flowing through each of the flow grooves. In the same plane of one end of the first electrode that flows,
A first inlet and a first outlet on the fluid fuel side are arranged, and the first
A plurality of ribs are erected on the first electrode so that the suction port and the first discharge port communicate with each other to the first communication portion, and the opening surface of the first suction port and the first discharge port of the first electrode is provided with a plurality of ribs that communicate with the first communication portion. A second suction port and a second discharge port on the fluid oxidizer side are disposed in the same plane at one end of the second pole through which the fluid oxidizer flows, in a direction different from that of the second pole. A plurality of ribs are provided upright on the second electrode so that the population and the second outlet communicate with each other up to the second communication portion.

(Function) According to the present invention, the structure is simple, the reliability of the seal is improved, the assembly work is reduced, and the number of parts and costs can be reduced.

(Example) An example of the present invention will be described with reference to FIGS. 1 and 2.

Reference numeral 11 is a matrix containing phosphoric acid as an electrolyte, and reference numerals 12 and 22 are first and second electrodes made of porous material such as carbon. The first electrode 12 on the fluid fuel side through which the fluid fuel flows is arranged on the upper surface of the matrix 11, and the second electrode 22 on the fluid oxidant side through which the fluid oxidizer flows is arranged on the lower surface of the matrix 11.

The first electrode 12 on the fluid fuel side has a plurality of ribs 13a,
13b, 13b, 13c, and 13c are arranged in parallel.

The rib 13a disposed at the center of these ribs is the longest, and the ribs 13b, 13b, and 13C113c at both ends are short. One end of these ribs is opened to the first opening 12a of the 118i12.

In addition, the first electrode 1 other than the first opening of the I-electrode I2 is
U-shaped protrusions 15a and 15b are formed along the flat plate frame shape of No. 2.
, 15c are formed.

On the other hand, 22 is the second electrode on the fluid oxidizer side, which has the same structure as the first electrode 12 on the fluid fuel side, and the corresponding structure is indicated by a number in the 20s, which is the number of the first electrode plus 10. is omitted.

Here, the directions of the inlet port 26 and the outlet port 27 on the fluid oxidizer side are 180 degrees opposite to the directions of the inlet port 16 and the outlet port 17 of the first pole 12 on the fluid fuel side.

As described above, the upper and lower sides of the unit cell structure arranged as the first electrode 12 on the fluid fuel side, the matrix 11, and the second electrode 22 on the fluid oxidant side are electrically conductive and gas permeable. A fuel cell main body is formed by stacking a plurality of unit cells with separators 30 and 30 disposed.

A box-shaped first case 40 is hermetically arranged on the fluid fuel side of such a fuel cell. This first case 40 is provided with a first intake manifold pipe 41 through which hydrogen is taken in and a first exhaust manifold pipe 42 through which the hydrogen is discharged.

Moreover, the inner surface of this first case 40 has a first suction side recess 4.
3 is formed, and a first suction manifold pipe 41 is communicated with the first suction side recess 43 . Further, a first discharge side recess 44 is provided in parallel with the first suction side recess 43, and the first discharge manifold pipe 42 is communicated with the recess 43.

Note that the recesses 43 and 44 do not intersect with each other,
It is provided via a first partition wall 45, and the open end of the first partition wall 45 is in sealing contact with the open end of the rib 13a.

Groove 1 formed by the ribs 13a, 13b, 13b
The opening surfaces of 6a, 16a, and 16a are the fluid fuel side inlet 16
The first suction recess 43 is opposed to the suction port 16.

Furthermore, the opening surfaces of the grooves 17a, 17a, 17a formed by the ribs 13a, 13c, 13c serve as a fluid fuel side discharge port 17, and the first discharge recess 44 is opposed to the discharge port 17.

Note that the grooves 16a, 16a, 16a and 1
A communication portion 18 is provided so as to communicate with 7a, 17a, 17a, and 17a.

On the other hand, the structure of the ribbed electrode 22 on the fluid oxidizer side is also similar, and the grooves 26a, 26a, 26a on the oxygen suction side form a second suction port 26 through which oxygen is sucked, and the grooves on the oxygen discharge side 27a, 27a, 27a form a second outlet 27. The rest of the structure is the same as the fluid fuel side, and each
It is expressed by adding 10 to the symbol on the fluid fuel side.

Further, the structure of the second case 50 is also similar to that of the first case 40, and each is represented by the symbol of the first case 40 plus 10.

The operation of the fuel cell configured as above will be explained.

When hydrogen is inhaled from the first intake manifold 41, it passes through the first intake recess 40, passes through the fluid fuel side intake port 16 of the first electrode 12, passes through the grooves 16a, 16a, 16a, and makes a U-turn at the communication section 18. grooves 17a, 17a, 17
a, hydrogen passes through the first discharge port 17 and is discharged from the first discharge recess 44 and the first discharge manifold 42;

Further, when oxygen is inhaled from the second suction manifold 51, it passes through the second suction recess 53 and the second outlet 26, and passes through the groove 26a.
, 26a, 26a, communication portion 28, groove 27a, 27a, 2
7a, oxidized fuel side discharge port 27, second discharge recess 54, second
Oxygen is exhausted from the exhaust manifold 52.

Due to this action, an electrochemical reaction occurs in the matrix 11, and electricity is generated.

According to the present invention, the seal structure can be integrated in the height direction as shown in FIG. 3, and only two stickers 60 are attached to each unit cell on both sides.

Next, the electrode is usually processed by cutting, but the efficient processing method of the present invention will be briefly explained with reference to the fourth drawing.

First, a U-shaped groove is formed in a flat plate H made of carbon using a milling cutter F, as shown in FIG. 2(A), to form a communicating portion R.

Next, as shown in (b), a plurality of grooves M are formed by cutting grooves using a disk-shaped cutting machine S.

It goes without saying that the present invention is not limited to the above-mentioned processing method, and may be carried out using commonly used cutting methods.

Further, in this embodiment, the openings of the ribs of the pair of electrodes were oriented 180 degrees apart from each other, but the openings may be arranged so that the directions of the open surfaces are perpendicular to each other by 90 degrees.

Further, in this embodiment, the electrodes are provided with the ribs described above, but the separator 30 may also be provided with the ribs described above.

〔Effect of the invention〕

The present invention having the structure described above has a simple structure, and the gas seal is different from conventional seals, in which it is necessary to attach at least four seals at different levels in each unit cell. Just put two stickers on it.

Since the structure does not involve applying stickers alternately, there is no need to worry about gas leaking from the seals, the assembly is easy, and the problem of electrode damage is eliminated.

In addition, conventionally, four cases were required for each of the four sides in which the manifolds were formed, but in the present invention, only two cases are required.

As a result, the present invention has the effect of reducing the number of parts, reducing costs, and eliminating seal leaks.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of the entire fuel cell showing an embodiment of the present invention, and FIG. The action diagram (b) in which hydrogen is discharged from the first exhaust port is a sectional view taken along line B-B in FIG. 1, and oxygen is inhaled from the second intake port,
An example showing a method of fabricating an electrode from the second discharge port, Fig. 5 is a perspective view of a conventional fuel cell, and Fig. 6 (a) is C of Fig. 5 in which a case for inhaling and discharging hydrogen is added. -C cross-sectional view for explaining how hydrogen is sucked in and discharged; (B) is a cross-sectional view taken along line D-D in Figure 5 with an additional case for sucking and exhausting oxygen, and explanation for sucking in and exhausting oxygen. 11...Matrix, 12...First electrode, 16...First inlet, 17...First Exhaust port, 18... First communication part, 22... Second electrode, 26... Second suction port, 27... Second discharge port, 28... Second communication part.

Claims (1)

[Scope of Claims] A pair of ribbed electrodes each having flow grooves for fluid fuel and fluid oxidant are disposed with an electrolyte-impregnated matrix sandwiched therebetween, and the fluid fuel and fluid oxidizer are flowed into each of the flow grooves. In a fuel cell in which a plurality of unit cells that output electrical energy are stacked with separators interposed therebetween under conditions where fluid fuel is flowing, there are
A first inlet and a first outlet on the fluid fuel side are arranged, and the first
A plurality of ribs are erected on the first electrode so that the suction port and the first discharge port communicate with each other to the first communication portion, and the opening surface of the first suction port and the first discharge port of the first electrode is provided. A second inlet and a second outlet on the side of the fluid oxidizer are disposed in the same plane of one end of the second electrode through which the fluid oxidizer flows, in a direction different from that of the second electrode. A fuel cell characterized in that a plurality of ribs are erected on the second electrode so that the inlet and the second outlet communicate with each other up to the second communication portion.