JPS5880272A - Fuel cell - Google Patents

Abstract

PURPOSE:To obtain a uniform electrode reaction and improve cooling capability of a cell by applying backpressure to each of gas supply grooves by reducing the number of outlet grooves of a reaction gas than the number of supply grooves of a gas separating plate in a matrix type fuel cell. CONSTITUTION:In a cell stack S constructed by stacking matually a unit cell 1 and a gas separating plate 4, supply grooves 2, 3 of hydrogen and air are interconnected through outlet grooves 2', 3' which have the reduced number than the number of supply grooves, via interconnecting cutting grooves 11. Thus, the cross section of an outlet passage is narrowed than that of an inlet passage so that the backpressure is applying to each supply groove from the outlet side. Concentration drop of reaction gas from the inlet side to the outlet side is compensated by increase of the reaction gas diffusion from the back of a gas electrode due to increase of the backpressure. Therefore, the electrode reaction is made practically uniform. Since manifold pipes are not narrowed, the amount of cooling air passing through a cooling plate 6 is increased and cooling efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a matrix fJ fuel cell, and in particular, to improve the gas separation plate to make the electrode reaction uniform.
&a To improve one's ability and one's purpose.

As shown in Figure 1, Jin's Hajido Pond consists of a hydrogen electrode, an air electrode, and an electrolyte retention matrix interposed between these electrodes (none of which are shown). and mutual Vc on both sides.
5F. Hydrogen supply groove (2) and air supply groove (
Carbonaceous gas separation plates (47) arranged with carbonaceous gas separation plates (47) arranged in do.

The battery stack (on the opposite side of the town is a pair of manifolds (7) and 7 for hydrogen supply, respectively.@2- and Mizuko-like)
) and a pair of air supply manifolds 18) +83 are installed, and hydrogen and air are sent to the respective gas supply grooves (2) and (3) through these manifolds. At the same time, the supplied air flows into the air passage (5) of the cooling plate [6] to cool the battery.

Now, what about the hydrogen supplied to the battery? Since it is a reformed product of methanol or natural gas, it contains about 20 volumes of carbon dioxide gas, and its flow rate is about 12 to 15 times the amount required for the reaction.

On the other hand, the air supplied to the battery also contains 1$ of Na in addition to the reactant gas, and 1!1g is used in the air cooling system.
In the case of 9, the flow rate is about 10 times the diameter of the reaction pupil, and most of it flows through the air passage (5) of the cooling plate (61).

If such hydrogen and air are supplied to the battery, they will diffuse into each supply groove (2) and the hydrogen electrode and air electrode and react, but this reaction will cause the effective components ( The partial pressure (concentration) at 1 m and 0 m is the same at the exit side because the population (IIt) of each supply groove is low. Therefore, the electrode reaction becomes non-uniform between the inlet and outlet sides, and the electrode characteristics It is a friend who has become a saving grace.

Conventionally, to prevent this, each outlet side manifold (7) (8
) to the inlet pipes (9) and (8) of the manifolds (7) and (8), respectively, to the inlet pipes (9J and small diameter (approx. One method is to increase the pressure in the side manifold and apply back pressure from the outlet side of each supply groove to compensate for the decrease in the concentration of the reactant gas by increasing the pressure and improving the diffusivity from the back side of the gas. It was broken.

According to this method, if the smooth flow of the supply gas is obstructed, the flow rate decreases at the corners, and in the case of air, the amount of cooling air flowing to the cooling plate decreases, making it impossible to cool the battery sufficiently. There was an interlayer.

The present invention solves such interlayer points by improving the supply #l of the gas separation plate, and will be explained below with reference to the drawings.

The gas separation plate shown in Fig. 3 has each supply #1 (2 bars 3J) arranged in the same line as the conventional one, with 5! It has a communicating notch U&, and through this notch 11tl, it communicates with one outlet groove 1 and one (1) smaller than the number of supply grooves.The number of outlet grooves is 4 to 1/4 of the number of supply grooves. It's Harukamushi for 1h.

In this way, the cross section of exit IIjl is changed to the cross section of 8 days 1 m11 passage L'C*6e, 5e,
) Therefore, pressure (back pressure) is applied to each supply groove from the outlet hook to the outlet grooves, which are smaller than the number of supply grooves, so the concentration drop from the inlet side to the outlet side of the reactant gas is due to this back pressure. Compensated by the diffusivity of the reaction gas from the back surface of the gas pole due to the rise, the i++ut reaction is calculated from the inlet side to the outlet mK and is approximately equal to -
can be converted.

In addition, in this system, the back pressure is obtained by improving the gas supply groove of the gas separation plate t4J, so there is no need to throttle the outlet manifold (7) and the outlet pipe (meg and uti) as in the conventional method. A smooth gas flow is obtained, and in particular, the amount of cooling air passing through the cooling plate 163 is increased, thereby improving the cooling effect.

In another embodiment shown in FIG. 4, each reaction gas supply groove (2) (3
The inlet side of J and each of the above-mentioned outlet grooves (ita5 is formed when the periphery of the gas separation plate 4J is left in the form of a thinner) 1
This gas separation plate (the peripheral part of each gas electrode that is in close contact with Shu) cuts into each gas supply groove (2) and the population of [37] and the outlet groove (6 and (31) to reduce the passage cross-sectional area of the outlet. Tashi,
An additional effect is obtained that the peripheral part of the gas electrode is not damaged or destroyed.

As described above, according to the present invention, when reformed hydrogen and air each containing Cot are used as gases to be supplied to a battery, a large number of gas supply grooves have cutouts that interconnect them near the outlet. Then, the number of grooves is smaller than the number of grooves formed.
Therefore, back pressure is applied to the gas supply groove by the outlet groove that narrows the cross section of the gas path, so there is no need to throttle the outlet side of the manifold as in the conventional case. This contributes to improving the characteristics of the battery, such as making it possible to substantially equalize the flow of cooling air across the sides and improving the cooling capacity of the cooling air.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a battery stack to which the present invention is applied, Fig. 2 is a flat view of an improved completed battery, Fig. 3 is a perspective view of a gas separation plate improved according to the present invention, and Fig. 4 8-Battery stack, 1-unit cell, 2.1. Hydrogen and air supply groove, 4.-Gas separation plate, 6- ...Cooling plate, (
5-Air passage), 7, 7'--Hydrogen supply manifold, 8.8-Air supply manifold.

Claims (1)

[Scope of Claims] ■ A battery stack in which unit cells and gas separation plates are stacked alternately, in which a number of vL gas supply capacitors formed in the primary gas separation plates are arranged near the outlet. The reactant gas passage on the outlet side (by the 5sUe outlet groove) has a notch that communicates these supply grooves with each other and an outlet groove that is smaller than the number of supply grooves. A fuel cell characterized in that pressure is applied to compensate for a partial pressure drop of 1 kM in the reactant gas from the population side of the IrII supply groove to the outlet. ■ About ti! , the fuel cell described in Patent Enclosure @ 1 Makiki, characterized in that the artificial side of the reaction gas supply groove and the 1IiJ outlet groove are formed by passing the -J gas separation plate in a tunnel shape. @liJ-Kameike Every few cells in the battery rack? v1 The fuel cell according to paragraphs 1 and 2 of the scope of the patent application, in which a cooling plate for cooling air passages is interposed.