JP3258378B2 - Fuel cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fuel cell using a solid polymer membrane.

[0002]

2. Description of the Related Art Conventionally, a fuel gas and an oxidizing gas of a fuel cell have been supplied orthogonally because of a manifold structure. There is also an example in which an internal header system is employed and a fuel gas and an oxidizing gas are allowed to flow in parallel (Japanese Patent Application No. 3-154558). However, as can be seen from this embodiment, the gas flow direction is gravity. There was no cooling water circulating without stagnating downward.

[0003]

When a solid polymer membrane is used as an electrolyte, many electrolytes cannot exhibit high performance unless they contain sufficient water.
For example, Nafion (produced by DuPont), which is a proton conductor, is a typical example. When a fuel cell is formed using these solid polymer membranes, a method of supplying one or both of gases introduced as a fuel and an oxidant is used as a method for supplying water to the membrane.

[0004] However, depending on the operating conditions of the fuel cell, water may drain on the surface of the separator. Although there is a thin groove for gas supply on the surface of the separator, if this narrow groove is covered with drain, gas supply becomes impossible and the performance is remarkably deteriorated.

In the conventional separator, such a situation is not taken into consideration, and in order to operate under conditions where moisture adheres to the surface of the separator, the gas utilization rate is reduced, the exhaust gas is increased, and the The drain had to be removed by the flow.

The present invention has been made in view of such circumstances, and the fuel gas supply groove and the oxidizing gas supply groove in the separator are made to flow in parallel, and the flow direction is made lower in the direction of gravity to drain and discharge. It is an object of the present invention to provide a fuel cell that can be operated under various conditions without lowering the gas utilization rate.

[0007]

According to the present invention, there is provided a fuel cell in which an oxidizer electrode and a fuel electrode are provided on both sides of a solid polymer membrane as a solid electrolyte membrane, and a fuel cell provided on both sides of the fuel cell. A separator, wherein the separator is formed on one side with an oxidizing gas supply plate formed with an oxidizing gas supply groove reaching the vicinity of the end , and on one side is substantially the same length as the oxidizing gas supply groove. It is near the end
A fuel gas supply plate having a fuel gas supply groove formed therein, and a cooling water plate disposed between the two gas supply plates and having a cooling water groove formed in a non-contact state with the fuel cell. A cooling water supply hole provided in a lower portion of the separator, and a cooling water drain hole provided in the separator positioned above the cooling water supply hole, so that a fuel gas and an oxidizing gas are respectively supplied to the fuel gas supply hole. And the cooling water is supplied from the lower part of the separator and then discharged from the cooling water drain hole through the cooling water groove. There is provided a fuel cell.

[0008]

According to the present invention, a fuel gas supply groove and an oxidant gas supply groove which are parallel to each other are provided on both surfaces of the separator, and the fuel gas and the oxidant gas flow downward in the direction of gravity (vertical direction) in the groove. Because it is configured to be discharged naturally, it can be operated under various conditions without lowering the gas utilization rate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Embodiment 1 Referring to FIG.

Reference numeral 1 in the drawing denotes a fuel cell power generator (cell). The fuel cell 1 has a configuration in which a solid polymer membrane as an electrolyte membrane and an oxidizer electrode 2 and a fuel electrode 3 are attached to both surfaces of the solid polymer membrane. Packings 4 are attached to the left and right of the fuel cell 1.

The two main surfaces of the fuel cell 1 and the packing 4 are sandwiched between separators 5. One side of the upper corner of the separator 5 is provided with a fuel gas supply hole 6.
A fuel gas discharge hole 7 is provided on one side of the lower corner, and a fuel gas supply groove 8 is provided in the center of one main surface of the separator 5 in the vertical direction . An oxidizing gas supply hole 9 is provided on the other side of the upper corner of the separator 5, an oxidizing gas discharge hole 10 is provided on the other side of the lower corner, and a central portion of the other main surface of the separator 5 is provided. Is provided with an oxidizing gas supply groove 11 in a vertical direction. Here, the fuel gas supply groove 8 and the oxidizing gas supply groove 11 are formed in parallel. Incidentally, reference numeral 1a in the drawing denotes a cell end seal.

In the fuel cell having such a configuration, the fuel gas (hydrogen) introduced from the fuel gas supply hole 6 is supplied from the header provided inside the separator 5 to the fuel cell 1 through the fuel gas supply groove 8 on the separator surface. The fuel is supplied to the fuel electrode 3 side. On the other hand, the oxidant gas (air) is introduced from the oxidant gas supply hole 9 and supplied to the oxidant electrode 2 side of the fuel cell 1 through the path between the fuel gas and the back surface.

As described above, according to the fuel cell of the first embodiment, the fuel cell 1 in which the oxidizer electrode 2 and the fuel electrode 3 are provided on both surfaces of the solid polymer membrane as the solid electrolyte membrane, A separator 5 provided on both sides of the battery cell 1; a fuel gas supply groove 8 and an oxidant gas supply groove 11 which are parallel to each other on both surfaces of the separator 5; Since it is configured to be naturally discharged downward in the direction of gravity in the groove, it is possible to greatly improve the gas utilization rate and obtain sufficient power generation performance even under various operating conditions. In particular, the utilization rate of the oxidizing gas (oxygen in the air) can be increased to 70% or more. Further, the operation is performed with the moisture content of the gas before being introduced into the fuel cell being equivalent to the saturated vapor at a temperature equal to or higher than that of the fuel cell, and continuous power generation is possible even in a situation where drainage occurs in the fuel cell. (Example 2)

Please refer to FIG. 2 and FIG. Here, FIG. 2 is an explanatory view of the fuel cell according to the second embodiment, and FIG. 3 is an exploded perspective view of a separator which is one configuration of the fuel cell of FIG. In addition,
1 are denoted by the same reference numerals and description thereof is omitted.

Embodiment 2 is an embodiment in which a method of flowing cooling water into a separator is employed. The separator 5 includes a fuel gas supply plate 21, an oxidizing gas supply plate 22, and a cooling water plate 23 interposed between these two supply plates. A cooling water supply hole 24 is formed at a lower portion of the separator 5, and a cooling water drain hole 25 is formed at an upper portion of the separator 5. The cooling water plate 23 is formed with a cooling water supply groove 26 that connects the cooling water supply hole 24 and the cooling water drain hole 25. On the oxidizing gas supply plate 22, a cooling water supply header 27 communicating with the cooling water supply hole 24 and a cooling water discharge header 28 communicating with the cooling water drain hole 25 are formed. The oxidizing gas supply plate 22 is formed with an oxidizing gas supply header 29 communicating with the oxidizing gas supply hole 9 and an oxidizing gas discharge header 30 communicating with the oxidizing gas discharge hole 10.

In the fuel cell having such a configuration, the cooling water enters through the cooling water supply hole 24 provided at the lower part of the separator, passes through the cooling water supply groove 26 provided on the cooling water plate 23, and flows through the cooling water drain hole 25 provided at the upper part of the separator. Is discharged. Thus, FIG.
By using the separator shown in (1), both the fuel gas and the oxidizing gas flow from the upper side to the lower side in the gas supply groove, and the cooling water can flow smoothly without forming an air pocket or the like.

In the above embodiment, the case where the fuel cell is composed of one fuel cell and the separators on both sides of the cell has been described. However, the present invention is not limited to this, and a large number of fuel cells and separators are alternately stacked. The configuration may be as follows.

[0018]

As described in detail above, according to the present invention,
The fuel gas supply groove and the oxidizing gas supply groove in the separator are made to flow in parallel, and the flow direction is downward in the direction of gravity, and the structure is configured to be discharged with drain so that the gas utilization rate can be reduced without decreasing the gas utilization rate. A fuel cell that can be operated under various conditions can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a fuel cell according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory view of a fuel cell according to Embodiment 2 of the present invention.

FIG. 3 is an exploded perspective view of a separator which is one configuration of the fuel cell of FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel cell, 2 ... Oxidizer electrode, 3 ... Fuel electrode, 4 ... Packing, 5 ... Separator, 6 ... Fuel gas supply hole, 7 ...
Fuel gas discharge hole, 8: fuel gas supply groove, 9: oxidant gas supply hole, 10: oxidant gas discharge hole, 21: cooling water supply plate, 22
... Oxidant gas supply plate, 24 ... Cooling water supply hole, 25 ... Cooling water drain hole, 26 ... Cooling water supply groove, 27 ... Cooling water supply header, 28 ...
Cooling water discharge header 28.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Joi Sueda 4--22 Kannon Shinmachi, Nishi-ku, Hiroshima, Hiroshima Prefecture Inside the Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Isao Hirata 4-chome, Kannon Shinmachi, Nishi-ku, Hiroshima, Hiroshima Prefecture No. 6-22 Inside Mitsubishi Heavy Industries, Ltd. Hiroshima Laboratory (56) References JP-A-60-163375 (JP, A) JP-A-60-236459 (JP, A) JP-A-3-102774 (JP, A) Kaihei 4-266706 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8/02 H01M 8/04 H01M 8/10

Claims (1)

(57) [Claims] 1. A fuel cell comprising an oxidant electrode and a fuel electrode provided on both sides of a solid polymer film as a solid electrolyte membrane, and separators provided on both sides of the fuel cell, respectively. Is an oxidizing gas supply plate formed with an oxidizing gas supply groove reaching one end near the end, and is substantially the same length as the oxidizing gas supply groove on one surface being parallel to the oxidizing gas supply groove.
A fuel gas supply plate formed with a fuel gas supply groove both reaching near the end, and a fuel gas supply plate disposed between the two gas supply plates;
A cooling water plate formed with a cooling water groove in a non-contact state with the fuel cell unit, wherein a cooling water supply hole is provided at a lower portion of the separator, and the separator is located above the cooling water supply hole. Cooling water drain holes are provided in the fuel gas supply grooves and the oxidizing gas , respectively.
The structure is such that the oxidizing gas supply groove is naturally discharged in the direction of gravity in the gravity direction, and the cooling water is supplied from the lower part of the separator and then discharged from the cooling water drain hole through the cooling water groove. Features fuel cell.