JP2560106Y2 - Fuel cell manifold plate - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manifold plate for a fuel cell, and more particularly, to an improvement in a parallel groove connecting a reaction gas section and a gas flow hole.

[0002]

2. Description of the Related Art As shown in FIGS. 4 and 5, a fuel cell A using two kinds of reaction gases comprises a solid polymer electrolyte membrane 02 sandwiched between an anode electrode substrate 03 and a cathode electrode substrate 04. Two manifold plates 0 each having a divided fuel gas section 05a and an oxidant gas section 06a
A cell stack 09 is formed by laminating a plurality of unit batteries 01 formed by laminating 5, 06 with a separator 08 interposed therebetween, and is compressed and sandwiched by a set of end plates 10 and 10 serving as a manifold by bolting. Also,
The reaction gas is composed of a fuel gas and an oxidizing gas, and the fuel gas is provided in the fuel gas section 05a including the anode electrode base material 03, while the oxidizing gas section is provided in the oxidizing gas section 06a including the cathode electrode base material 04. Are simultaneously introduced and discharged. As a result, an oxidation reaction of hydrogen occurs on the anode side and a reduction reaction of oxygen occurs on the cathode side through the solid polymer electrolyte membrane 02, and hydrogen ions move in the solid polymer electrolyte membrane, and electrons are extracted to an external circuit. This generates electrical energy.

A unit cell in this type of fuel cell simply has two manifold plates, for example, having a phase of 90.
In other words, the structure was such that only the back surfaces were opposed to each other via a seal material, and the seal material was also laminated on the outer surface.

[0004]

In such a conventional structure, the sealing material protrudes into the parallel groove due to the tightening pressure at the time of assembling the cell stack by compressing it with one set of end plates, and the sectional area of the parallel groove is increased. And the flow of the reaction gas is hindered.

[0005] In the unit cell, the hydrogen gas introduced into the fuel gas area is always in a humid state, and the supply amount of the humidified fuel gas increases as the current density increases. In the oxidant gas area, both water produced by the reaction and water that has moved along with the hydrogen ions in the solid polymer electrolyte membrane appear at the cathode. For this reason, during the continuous operation of power generation where the history of the operating state remains, the presence of moisture on the electrode surface may hinder the diffusion of the reaction gas and the electrochemical reaction. It is not easy to evenly distribute the reaction gas to the unit batteries.

The present invention has been made in view of such problems of the prior art, and prevents a sealing material at the time of press-fitting a cell stack from entering a parallel groove to narrow a flow path thereof. It is an object of the present invention to provide a fuel cell manifold plate that can adjust a gas flow rate flowing in a parallel groove portion and uniformly distribute the gas to each unit cell, and can easily recover a voltage when a sudden voltage drop occurs in an arbitrary unit cell. I do.

[0007]

According to the present invention, a plurality of manifold plates each having a fuel gas section and an oxidizing gas section divided by a solid polymer electrolyte membrane sandwiched between electrodes are provided. The unit batteries are stacked via a sealing material and a separator to form a cell stack,
In a fuel cell formed by tightening a set of end plates which also serves as a manifold, grooves protective plate covering the each of the parallel grooves provided a gas zone and the gas flow hole of the manifold plate so as to communicate the provided groove portions Mani
It is fitted flush with the surface of the hold plate,
Can also rotate into a plurality of parallel grooves of the manifold plate
Each of the moving blades is supported by pivoting the moving blade.
These channels can be opened and closed and can be operated externally.
The present invention provides a fuel cell manifold plate provided with a flow rate adjusting means .

[0008]

According to the present invention, when the cell stack is compressed and held by the mechanical fastening means (bolt fastening, air cylinder, hydraulic cylinder, etc.) of the end plate, the seal is fastened by the pressing force. The material expands and tries to escape into the parallel grooves, but the intrusion is prevented by the groove protection plate, and the parallel grooves maintain their original cross-sectional shape, so that the flow of the reaction gas is hindered. There is no.

Further, since the gas flow rate of the unit batteries of the cell stack can be individually adjusted by the gas flow rate adjusting means, a uniform gas flow rate can be distributed, and the diffusion of the reaction gas and the electrochemical reaction can be smoothly performed. That is, according to the fuel cell manifold plate of the present invention, the cross-sectional area of the parallel groove of the unit cell is not reduced by the sealing material, and the flow rate of the reactant gas to each unit cell can be made uniform. The voltage is also uniform, and the power generation function of the fuel cell can be exhibited extremely smoothly.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. The same members as those in the general example are denoted by the same reference numerals, and description thereof will be omitted. The unit cell 21 to which the fuel cell manifold plates 22 and 23 of the embodiment of the present invention are applied includes:
As shown in FIG. 2, the fuel gas side manifold plate 22 formed in a frame shape of a plane square, and the solid polymer electrolyte membrane 02 with the same shape and the same size, changing the phase by 90 degrees and facing the back surface, A fuel gas section comprising an oxidant gas side manifold 23 overlapped via a sealing material 07 integrally held in an internal space, into which an anode electrode substrate 03 and a cathode electrode substrate 04 are respectively fitted as electrodes; 22c, an oxidizing gas section 23c is formed.

The manifold plate 22 on the fuel gas side is shown in FIG.
As shown in (a) of the surface (separator side) 22a, gas flow holes 24 having a pair of elongated rectangular cross-sections are formed in each of the four peripheral edges, and the flow holes at the opposed positions are used as fuel gas. Hydrogen H2 introduction holes 25, ₂
5, and discharge holes 26, 26. On the other hand, the flow holes facing the lateral position are flow holes 27 for introducing oxygen O ₂ as the oxidizing gas, and flow holes 28 for discharge.

The fuel gas section 22c and the introduction hole 25
A plurality of parallel grooves 31 are provided as parallel grooves 30 for communicating the flow of hydrogen H ₂ with the discharge holes 26 and the discharge holes 26, respectively.
And a stainless steel groove protecting plate 34 is fitted flush with the surface 22a. In addition,
2 shows a case where the parallel grooves 31 are separated by partition walls 32. FIG.

As shown in FIG. 1B, the gas flow rate adjusting means 40 is provided on the back surface 22 b of the manifold plate 22.
A worm wheel 43 is provided in one corner,
Is projected outside the manifold plate 22. A small gear 44 integrally formed with a drive pulley 45 is meshed with the worm wheel 43. In addition, idler pulleys 46 are disposed at the other three corners of the edge of the fuel gas section 22c, and rotating blades 47 are rotatably supported in the parallel grooves 31 and extend therefrom. A shaft 48 is provided to protrude from the back surface 22 b of the manifold plate 22. In addition, a stationary blade 49 is used as a partition for forming the parallel groove 31. And each pulley 4
A string 50 is provided in an extended state so that the strings 50 and 46 and the extension shaft 48 are wound one by one and can be interlocked.

With the above configuration, when a plurality of unit batteries 21 are stacked and pressed together to assemble into a cell stack 09, conventionally, as shown in FIG.
When the pressing force F by the tightening of 0 and 10 is also applied to the surface of the sealing material 07, the sealing material 07 expands and
1 is reduced completely by the groove protection plate 34, and the cross-sectional area of the parallel groove 31 is maintained in its original state. It does not degrade the function of 21.

Further, in this embodiment, after measuring the voltage of each unit cell 21 in the cell stack 09 and calculating the average cell voltage, the unit cell 21 lower than the average cell voltage is compared with the others. The flow rate of the supplied reactant gas is adjusted to approach the average cell voltage. That is, by turning the operation shaft 42 and rotating the worm wheel 43 by the worm 41,
The drive is transmitted to a small gear (not shown) engaged with the worm wheel 43, and the pulley 4 formed integrally with the small gear is rotated. By moving the extension shaft 48 attached to the string 50 in the direction of the arrow (X2), the moving blade 47 attached to the extension shaft 48 is rotated in the direction of the arrow (X3). . Thereby, the parallel groove 3
It adjusts the flow rate of hydrogen H ₂ by reducing or closing the first flow path. Also in the manifold plate 23 of the oxidant gas side, has the same configuration as the fuel gas side, substantially the same effect can be obtained even with respect to oxygen O _2. In addition, at the time of high-output (high current density) power generation, a sudden voltage drop may occur due to blockage of a reaction site due to an increase in reaction generated water on the electrode surface or water moving in the membrane. In this case, the voltage dropped sharply. An experimental result showing that a voltage recovery was obtained by concentrating the cell stack supply gas to the unit battery 21 was obtained, and it is also possible to achieve a voltage recovery at the time of a voltage drop in an arbitrary unit battery 21. I have confirmed.

Although the embodiment of the present invention has been described above, the present invention is not necessarily limited to this embodiment, and even if the design is changed without departing from the scope of the present invention, the present invention is included in the present invention. For example, in the embodiment, the groove protecting plate is made of stainless steel. However, other materials may be used as long as the material is a carbon sintered plate or a gas dense electronically conductive material. When the parallel groove is formed with a partition, the gas flow rate adjusting means is provided with a required number of ventilation holes having the same shape and the same cross-sectional area as the parallel groove at a position where the parallel groove faces the gas flow hole. It is also possible to provide a slide plate and project its handle portion from the side surface of the manifold plate so as to operate the slide plate.

[0017]

According to the fuel cell manifold plate of the present invention, since the groove protecting plate covering the parallel groove communicating between the reactant gas area and the gas circulation hole is provided, the invasion of the sealing material is prevented. Since the cross-sectional area of the parallel groove is maintained in the original shape, the power generation function of the reaction gas can be sufficiently exhibited. In addition, since the gas flow rate adjusting means is provided for each unit cell, the amount of reactive gas distributed to each unit cell can be made uniform, so that the voltage of the cell stack is smoothed and the average voltage is improved (during high current density power generation). Not only can be achieved, but also the voltage can be restored when the voltage of any unit battery drops.

[Brief description of the drawings]

1A and 1B are views showing a fuel cell manifold plate according to an embodiment of the present invention, wherein FIG. 1A is a plan view on the front side, FIG. 1B is a plan view on the back side, and FIG. It is a partial expansion perspective view of a wing.

FIG. 2 is a partially omitted vertical sectional view of a unit battery according to an embodiment of the present invention.

FIG. 3 is an explanatory view showing a state in which a sealing material enters into a parallel groove in a conventional manifold plate by pressing.

FIG. 4 is a longitudinal sectional view showing a basic configuration of a unit battery.

FIG. 5 is a partially exploded perspective view showing the entire configuration of a conventional fuel cell.

[Explanation of symbols]

 A fuel cell 02 solid polymer electrolyte membrane 03 anode 04 cathode 07 sealing material 09 cell stack 10 end plate 21 unit battery 22 manifold plate (fuel gas side) 22c fuel gas area 23 manifold plate (oxidant gas side) 23c oxidant Gas section 24 Gas flow hole 30 Parallel groove 34 Groove protection plate 40 Gas flow adjusting means

Continuation of the front page (56) References JP-A-54-154046 (JP, A) JP-A-3-257760 (JP, A) JP-A-63-307671 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A plurality of unit cells each comprising a stack of two manifold plates each having a fuel gas section and an oxidizing gas section divided by a solid polymer electrolyte membrane sandwiched between electrodes, are sealed with a sealing material. And a fuel cell that is stacked with a separator interposed therebetween to form a cell stack, and tightened with a set of end plates also serving as a manifold.
A groove protecting plate covering each of the parallel grooves provided so as to communicate the gas area of the manifold plate and the gas circulation holes is flush with the surface of the manifold plate provided with the grooves.
The manifold plates are fitted face-to-face, and
A rotatable moving blade is supported in a number of parallel grooves to rotate the moving blade.
Each channel can be opened and closed by moving
First, a fuel cell manifold plate provided with gas flow rate control means that can be operated from the outside .