JPS6262413B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fuel cells, and in particular to manifold type fuel cells.

A fuel cell is provided with a structure for supplying and discharging fuel and an oxidant (eg, air). One method is an internal passage type in which a common flow path is provided for supplying and discharging gas within the electrode, but this method has a complicated electrode structure and requires difficulty in supplying gas to the gas reaction section. This tends to result in non-uniformity and is almost impossible to implement, especially in large fuel cells.

For this reason, as shown in Figs. 1 to 3, through the manifolds provided on the four sides of the stacked battery,
A manifold type fuel cell in which gas is supplied and discharged is used as a large fuel cell.

FIG. 1 is an exploded perspective view of battery components, FIG. 2 is a perspective view showing a stacked state, and FIG. 3 is a cutaway plan view of essential parts showing a state in which the stacked batteries are arranged in a storage tank.

In these figures, 1 is a fuel electrode, and 2 is an air electrode, which are made of, for example, graphite fiber, and each has a large number of ribs on one side to form a gas flow path 3, and the other flat surface has a gas flow path 3. For example, the catalyst layer 4 is provided by coating graphite powder in which platinum is diffused. These fuel electrodes 1 and air electrodes 2 are made of, for example, an electrolyte holding matrix (hereinafter referred to as a matrix) holding an electrolyte such as phosphoric acid.
5, and the gas flow paths 3 provided therein are arranged so as to be perpendicular to each other, thereby forming a unit cell. The unit cells configured in this way are stacked with a fuel and air separator 6 interposed therebetween. Reference numeral 7 denotes a cooler, in which a cooling pipe 8 is buried in the groove, one for each unit cell, and both ends of the cooling pipe 8 are connected to each other via an inlet branch pipe 9 and an outlet merging pipe 10. , an inlet main pipe 11, and an outlet main pipe 12.

Reference numeral 13 denotes a manifold that is attached to the four sides of the stacked batteries 14 stacked in this way and forms a space for gas supply and discharge. Each manifold 13 includes:
Gas supply pipes 15a, 15b, gas discharge pipe 16a,
16b is provided to penetrate the storage tank 17, and allows gas to be supplied and discharged from outside the storage tank 17. Reference numerals 18 and 19 are cooling water supply pipes and cooling water discharge pipes which are piped through the storage tank 17 and the manifold 13 and connected to the main inlet pipe 11 and the main outlet pipe 12 in the manifold 13.

In a fuel cell having such a configuration, as shown in FIG. 3, hydrogen serving as a fuel flows in the direction of the solid line arrow from the gas supply pipe 15a, and air flows in the direction of the dashed line arrow from the gas supply pipe 15b. Electricity is generated through an electrochemical reaction in the catalytic part.

However, in this manifold type fuel cell, the gas seal in the manifold 13 is
3 and the ends of the four side surfaces of the stacked battery 14, extremely high dimensional accuracy is required on the four side surfaces.
Furthermore, since the cooling pipes are also arranged within the manifold, the structure is extremely complicated and manufacturing is not easy.

The present invention was made in order to eliminate these problems, and aims to provide a manifold type fuel cell with a simple structure and high reliability. A plurality of unit cells each having an electrode and an oxidizer electrode are stacked with a separator in between, and a manifold for supplying and discharging gas to and from the fuel electrode and the oxidizer electrode is disposed on the side surface of the unit cell. In the fuel cell, the gas flow path for the fuel electrode and the oxidizer electrode, which are formed of a plurality of parallel grooves disposed in the electrode or in the separator, are provided so as to be orthogonal to each other. are connected to a gas supply port and a gas discharge port provided in a manifold on one side, respectively, and the gas flow path uses the gas supply port and discharge port as an inlet and an outlet, respectively, and connects the fuel electrode and the oxidizer. a first flow path consisting of a plurality of grooves that cross the agent electrode; and at least one gas flow control partition arranged in the direction of the grooves that controls gas flow between the grooves forming the first flow path. a second flow path comprising a wall, a groove interconnecting the first flow path at a position remote from the supply port and the discharge port; This is characterized by a closed flow path formed by a blocking member that abuts the flow path.

That is, the present invention was developed by focusing on the fact that the conventional manifold type fuel cell has manifolds attached to four sides of the stacked battery, which makes the structure very complicated. Alternatively, the gas flow paths provided in the separator may be structured to have a reversal function, and the gas flow paths for the fuel electrode and the oxidizer electrode may be arranged so as to be perpendicular to each other. It is possible to arrange a fuel manifold and an air manifold with gas supply ports and exhaust ports for the fuel electrode and oxidizer electrode on two adjacent sides, achieving the desired purpose. It is something to do.

Examples will be described below.

Fig. 4 is an exploded perspective view of the battery components of one embodiment, Fig. 5 is a plan view of the main parts of Fig. 4, Fig. 6 is a sectional view taken along line A-A in Fig. 5, and Fig. 7 is a storage tank. FIG. In these figures, the same parts as in FIGS. 1 to 3 are given the same reference numerals.

20 are the fuel electrode 1 and the air electrode 2 of this example.
The gas flow path 3 provided on one surface of the electrode substrate 20 is an electrode substrate used in the electrode substrate 20.
has a plurality of grooves parallel to a pair of side surfaces (the flow path formed by these grooves is referred to as a first flow path), and these grooves are arranged so that the electrode substrate 20 is It is divided into three groups of flow channels by partition walls 21a and 21b formed by impermeability treatment with plastic, the center flow channel being for gas supply and the flow channels on both sides for gas discharge. A groove that interconnects the plurality of grooves of the first flow path is located at a position far from the gas supply port 3a and gas discharge port 3b of these flow paths (the flow path formed by these grooves is called a first flow path). 2 flow paths) are provided. On the side opposite to the side where the gas supply port 3a and the gas discharge port 3b of the fuel electrode 1 and the air electrode 2 are provided, there is a plate that is in close contact with the side surface of the fuel electrode 1 and the air electrode 2 to prevent gas flow. Gas stops 26 and 27 are provided.

In the fuel electrode 1 and the air electrode 2 configured in this way, the gas supplied into the electrode substrate 20 from the respective gas supply ports 3a passes straight through the first flow path and then passes through the gas stopper 26 or 27. At the same time, the first flow path and the second flow path are prevented from going straight.
The gas changes direction at the bent portion 3c formed by the flow path, flows through the first flow path, and is discharged from the gas outlet 3b. Therefore, a uniform flow of gas can be formed within the electrode substrate 20.

And, this fuel cell has these electrode substrates 2
0 are each treated with a catalyst corresponding to the fuel air and fixed with a matrix, and arranged so that their flat surfaces face each other and the gas flow paths for fuel and air are in cross flow. stopper 2
6 and 27 are assembled, and a fuel manifold 24 and an air manifold 25 are fixed to two adjacent sides of the stacked battery where the gas supply port 3a and the gas discharge port 3b are provided, and the battery is placed inside the storage tank 17. is stored in. Note that the cooling water supply pipe 18 and the cooling water discharge pipe 19 are arranged on one side of the manifold that is not fixed.
Gas and cooling water piping are both connected to the storage tank 17.
It penetrates and is led out to the outside.

When hydrogen and air, which are fuel gases, are supplied to a fuel cell configured in this way, hydrogen flows into the electrodes as shown by the solid arrows in Figure 7, and air flows into the electrodes as shown by the broken arrows. It then makes a U-turn and flows, at which time it reacts at the catalyst and generates electricity.

In the fuel cell of this example, the manifolds are provided only on two adjacent sides, and the cooling water piping is not arranged inside the manifold.
The structure becomes very simple. Furthermore, since the gas flows of fuel and air are orthogonal to each other, gas diffusion performance is good. Furthermore, since the cooling water piping is not provided within the manifold, water leakage from the cooling water piping or gas leakage from the gas seal portion of the manifold can be easily monitored, greatly improving reliability.

When configuring the gas flow paths for the fuel electrode and air electrode, the number of flow paths on the inlet side is set higher than the number of flow paths on the outlet side, taking into account that fuel gas is consumed according to the direction of flow. If it is increased, the density of fuel molecules acting on the catalyst can be made uniform, which has the effect of making it possible to generate electricity uniformly over the entire electrode surface.

In the above embodiment, an example was explained in which gas flow paths for fuel and air were provided in the fuel electrode and the air electrode, which were arranged opposite to each other via a matrix. It is also used in a fuel cell in which a separator is provided with gas flow paths for fuel and air, and operates in the same manner and can obtain similar effects.

As described above, the fuel cell of the present invention provides a manifold type fuel cell with a simple structure and high reliability, and has great industrial effects.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of the battery components of a conventional manifold fuel cell, Fig. 2 is a perspective view showing the same stacked state, and Fig. 3 is the same stacked battery arranged in a storage tank. FIG. 4 is an exploded perspective view of the main parts of a battery component of an embodiment of the fuel cell of the present invention, and FIG. 5 is a plan view of the main parts of FIG. 4. , Figure 6 is A of Figure 5.
-A sectional view and FIG. 7 are cutaway plan views of essential parts showing a state in which similarly stacked batteries are arranged in a storage tank. 1...Fuel electrode, 2...Air electrode, 3...Gas flow path, 3a...Gas supply port, 3b...Gas discharge port,
3c... Gas diversion section, 4... Catalyst, 5... Matrix, 6... Separator, 15a, 15b...
Gas supply pipe, 16a, 16b...Gas discharge pipe, 1
7...Storage tank, 18...Cooling water supply pipe, 19
... Cooling water discharge pipe, 20 ... Electrode substrate, 21a,
21b...Partition wall, 24...Fuel manifold, 25...Air manifold, 26, 27...
...Gus Stopper.

Claims (1)

[Scope of Claims] 1. A plurality of unit cells each having a fuel electrode and an oxidizer electrode facing each other via a matrix are stacked with a separator interposed therebetween, and a gas supply to the fuel electrode and the oxidizer electrode is provided on the side surface of the unit cell. A gas flow path for the fuel electrode and the oxidizer electrode, which is provided with a discharge manifold and is comprised of a plurality of parallel grooves arranged in the fuel electrode and the oxidizer electrode or in the separator. In a fuel cell in which the gas flow paths are arranged to be perpendicular to each other, the gas flow paths communicate with a gas supply port and a gas discharge port provided in a manifold on one side, respectively, and the gas flow paths
a first channel consisting of a plurality of grooves that cross the fuel electrode and the oxidizer electrode, using the gas supply port and the gas discharge port as an inlet and an outlet, respectively; and a gap between the grooves forming the first channel; at least one partition wall for controlling gas flow arranged in the direction of the groove, and a groove interconnecting the first flow path at a position far from the supply port and the discharge port. A fuel cell comprising a closed flow path formed by a second flow path and a blocking member that abuts the first flow path at a position far from the supply port and the discharge port. 2. The fuel cell according to claim 1, wherein the number of channels constituting the gas supply port is greater than the number of channels constituting the gas discharge port.