JPH0160903B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an air-cooled fuel cell, and particularly to a fuel cell in which cooling air and reaction air are separately supplied.

(b) Prior Art Phosphoric acid electrolyte fuel cells require cooling to maintain an operating temperature of 180°C to 200°C. Air cooling methods include a method in which air sent to a common manifold is distributed to each passage as reaction air and cooling air, and a method in which cooling air is supplied separately from reaction air.

The former has the advantage that the pattern of each passage including the reaction hydrogen gas passage is simple, but it is difficult to allocate the amount of air required for reaction and cooling to each passage, and the battery reaction and battery temperature are The balance is disrupted, which is unfavorable in terms of battery characteristics.

On the other hand, in the latter case, reaction air and cooling air are separately supplied using a static screw and a manifold drawer as shown in Figures 1 and 2, so the pattern of each passage is complex, resulting in high flow resistance and the need for a large-capacity blower. There were drawbacks such as:

In view of this, the present applicant has proposed a fuel cell that is capable of separately supplying cooling air and reaction air by making slight improvements to a cell stack that commonly supplies cooling air and reaction air. did. (Japanese Patent Application No. 57-157133) As shown in FIGS. 3 and 4, the proposed battery is attached to the stack by having each cooling plate 2 interposed in the battery stack 1 protrude from the air circulation surface of the stack. The cooling air passage 5 exposed at each window 4 is connected to the inside of the cooling air manifold 6 installed on the reaction air manifold 3. .

In this case, the inside of the reaction air manifold 3 is separated by each protruding cooling plate 2', so the inside of the reaction air manifold 3 is
Openings 7 corresponding to the substack 1' between each cooling plate 2 are provided on one side of the cooling plate 2, and an auxiliary manifold 8 is attached to cover these openings 7. The hydrogen flow surface of the stack 1 is provided with a hydrogen gas manifold 9 as usual.

Therefore, the reaction air is supplied from each opening 7 through the auxiliary manifold 8 in a direction perpendicular to each reaction air passage of the substack, and therefore it is difficult to uniformly introduce the reaction air into each passage arranged in the air flow direction. That is, if the amount of supplied air is large, this is not a big problem, but if the amount of supplied air is not large, the reaction air passages that are farther away from each opening 7 tend to introduce a larger amount of air, which adversely affects the characteristics of the battery due to non-uniformity of the reaction. Sending an additional amount of air to eliminate this non-uniformity places a corresponding burden on the blower, resulting in problems such as loss of efficiency.

(c) Purpose of the Invention The purpose of the present invention is to provide a cooling air separation type fuel cell having a simple configuration, and in particular, to solve the above-mentioned problems and uniformly supply reaction air to each passage. The goal is to improve battery characteristics.

(d) Structure of the Invention The present invention comprises sequentially superimposing a reaction air manifold and a cooling air manifold on the air circulation surface of a battery stack, and each cooling plate interposed in the stack is provided to protrude from the air circulation surface. The fuel cell is of a type in which a cooling air passage is communicated with a cooling air manifold, and a large number of air reactors are provided in the reaction air manifold separated by the protruding cooling plates, corresponding to each substack. It is characterized by extending bottomed pipes each having an air outlet.

Another feature of the present invention is that an auxiliary manifold communicating with the pipe is attached to one side of the reaction air manifold, and an air outlet of the pipe opens toward the inner surface of the reaction air manifold. Be at the point where you are. Furthermore, the present invention is characterized in that the reaction air flow and the cooling air flow within the stack are configured to flow in opposite directions.

(E) Example A battery stack 1 according to the present invention includes a unit cell in which an electrolyte-impregnated matrix is inserted between negative and positive gas electrodes,
A large number of carbonaceous gas separation plates each having reaction gas (hydrogen gas and air) passages arranged in intersecting directions on both sides are stacked alternately, and air passages 5 are arranged in every 4 to 5 unit cells (substack). The upper and lower end plates are tightened with a carbonaceous cooling plate 2 interposed therebetween.

This stack configuration is similar to a so-called die gas system that commonly supplies reaction air and cooling air, but in the present invention, each cooling plate 2 is provided protruding from the air circulation surface of the stack to form a cooling air manifold 6. The cooling separation method was adopted by communicating with the

In this case, the interior of the reaction air manifold 3 is divided into compartments A corresponding to the air flow surfaces of each substack 1' by the protruding cooling plate 2', but the longitudinal direction of each compartment A is , as shown in FIGS. 5 and 6, each opening 7 has a large number of air outlets 10'.
A bottomed pipe 10 is extended.

One end of these pipes 10 may be closed with the inner surface of the side wall of the reaction air manifold 3 instead of having a bottom in advance, and the other end of the pipe 10 is connected to the auxiliary manifold 8.
It is open inward. Air outlet 1 of each pipe 10
0' opens toward the inner surface of the reaction air manifold 3 at intervals of about 2 cm, and the blown air once hits the inner wall of the manifold as shown by the arrow in Fig. 6, and is supplied to each reaction air groove of the substack 1'. .

Furthermore, if the diameters of the air outlet ports 10' are all the same, the air pressure will cause the outlet amount to increase the further away from the pipe inlet, and the amount of air supplied to each reaction air groove will become uneven. The holes are drilled in the range of 12 mmφ to 7 mmφ so that the diameter decreases gradually. The material of the pipe 10 is stainless steel or carbon in consideration of heat resistance and acid resistance.

Battery stack 1 is on the reaction air inlet side (approximately 150℃)
Since the temperature becomes higher towards the outlet side (approximately 180℃),
If cooling air is supplied from the outlet side of the reaction air,
Temperature gradients within the stack can be reduced.

Therefore, the cooling air manifold 6 on the outlet side (inlet side) is installed on the reaction air manifold 3 on the inlet side (outlet side), and as shown in FIG. The airflow (〓) is configured to be a counterflow.

It is not necessary to provide the pipe 10 as described above in the outlet-side reaction air manifold 3, and it is sufficient to simply provide an outlet corresponding to each substack 1' in the side wall of the manifold.

(E) Effects of the Invention According to the present invention, by making slight modifications to the battery stack that uses common reaction air and cooling air, it is possible to create a cooling air separation system. In comparison, the pattern of each gas passage is extremely simple, and the fabrication of the gas separation plate and cooling plate is simplified.

In addition, a portion protruding from the cooling plate interposed in the battery stack partitions the inside of the reaction air manifold, and a pipe with a large number of air outlets extends within each compartment, so that the reaction air of each substack is Reaction air can be smoothly introduced into the passage, and in particular, if the air outlet is opened toward the inner surface of the manifold, the blown air can be uniformly distributed to the reaction air passages in the vertical direction of the substack, and the diameter of the air outlet can be smoothly introduced. By making the amount smaller sequentially from the pipe inlet side, the blown air is evenly distributed to the reaction air passages in the left and right directions of the substack, and it is possible to prevent characteristic deterioration due to uneven distribution.

Furthermore, if the cooling air flow and the reaction air flow in the stack are made to flow in opposite directions, excellent effects such as making it possible to equalize the temperature gradient in the stack and improving the battery life can be achieved.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are both plan views of a conventional air-cooled fuel cell having separate cooling paths. 3 to 6 show the fuel cell of the present invention, FIG. 3 is a partially exploded slope view, FIG. 4 is a slope view of the same battery stack, FIG. 5 is an enlarged slope view of the main parts of the same, and FIG. is also an enlarged sectional view of the main part. 1...Battery stack, 1'...Sub stack, 2...
Cooling plate, 2'...Cooling plate protrusion, 3...Reaction air manifold, 5...Cooling air passage, 6...Cooling air manifold, 8...Auxiliary manifold, 9...Reaction hydrogen manifold, 10...Pipe, 10' ...air outlet,
A...Separate room.

Claims (1)

[Scope of Claims] 1. In an air-cooled fuel cell equipped with a cell stack including a plurality of cooling plates each having a cooling passage formed therein, each of the cooling plates has a protruding portion in which the cooling passage is opened on a reaction air circulation surface. The protruding portion airtightly penetrates the reaction air manifold attached to the battery stack and communicates with the inside of the cooling air manifold provided on the reaction air manifold, and the cooling plate protruding portion In the reaction air manifold separated by , pipes each having a large number of air outlets are installed from an opening on one side of the reaction air manifold, corresponding to the sub-stack between each cooling plate, and each pipe has a plurality of air outlets. An air-cooled fuel cell characterized in that a communicating auxiliary manifold is attached to the one side of the reaction air manifold. 2. The air-cooled fuel cell according to claim 1, wherein the air outlet of the pipe opens toward the inner wall of the reaction air manifold. 3. The air-cooled fuel cell according to claim 1, wherein the reaction air flow and the cooling air flow within the cell stack are configured to flow in opposite directions.