JPS6188464A - Fuel cell - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] Non-invention 1-1: This invention relates to fuel cells, and particularly relates to fuel cells that can be operated safely and with high reliability.

[@Ming background]

In general, a fuel pond that directly exchanges the chemical energy of fuel into electrical energy converts the chemical energy of the fuel into heat, and generates stains by operating the machine with the thermal fluid obtained from the heat. Unlike conventional energy conversion devices, it is possible to generate efficiency higher than the Carnot cycle, which is the upper limit of thermal cycles. For this reason.

It is seen as a promising high-efficiency power generation device, and research and development is underway.

FIG. 1 is a perspective view showing a typical example of such a fuel cell.

A general unit cell unit of a fuel cell is a separator l
, a fuel electrode 2, an electrolyte plate 3, and an air electrode 4. The fuel electrode 2 is supplied with fuel 5, and the air plate 4 is supplied with an oxidizing agent 6 such as air containing oxygen.

The electrolyte plate 3 is impregnated with 'i solyte.

The twisted fuel, etc. 2 and the air electrode 4 are porous, and the falcon 5 and the oxidizing agent 6 pass through each electrode and reach the surface of the electrolyte plate. reacts.

The protein pA plate 3 has the property of allowing ions to pass therethrough and preventing air and the like acting as the fuel 5 and oxidizing agent 6 from passing therethrough.

The separator 1 is a boundary with other cells and has the role of separating fuel and oxidizer.

Since the output of a unit cell of a fuel cell is very small, a stacked battery is constructed by stacking unit cells in multiple stages.

FIG. 2 is a perspective view of a fuel cell stack including stacked cells and the elements necessary to operate them.

In FIG. 2, the fuel cell stack includes a separator 1,
Fuel electrode 2. Electrolyte plate 3. Each side of a stacked battery in which unit cell units each consisting of an air electrode 4 are stacked is covered with a fuel Roman manifold 7, a fuel Roman manifold 8, a saponifying agent Roman manifold 9. An oxidizer outlet manifold 10 surrounds the
It is constructed by sandwiching the top and bottom of a laminated pond between end plates 12 and then fixing it with tie bolts 11, and surrounding the whole with a pressure vessel 13. The fuel supply pipe 14 is connected to the fuel manifold 7, and the fuel discharge pipe 15 is connected to the fuel quantity manifold 8.

The encased oxidizing agent supply pipe 16 is connected to the oxidizing agent manifold 9, and the oxidizing agent discharge pipe 17 is connected to the oxidizing agent manifold 10. Moreover, the inside of the pressure vessel 13 is filled with inert gas.

The fuel 5 is supplied from the outside of the pressure vessel 13 into the fuel manifold 7 through a fuel supply pipe 14 . The ff1M that has entered the fuel manifold 7 is discharged to the fuel manifold 8 after passing through the fuel electrode 2 of each cell constituting the stacked battery to exchange ions with the air electrode 4 through the man electrolyte plate 3. Ru. The waste fuel recovered by the fuel quantity Romanifold 8 is discharged into the pressure vessel through the fuel discharge pipe 15.

On the other hand, the oxidizing agent 6 is supplied from the outside of the pressure vessel 13 to the oxidizing agent manifold 9 through an oxidizing agent supply pipe 16. The fuel that has entered the oxidizing manifold 9 is introduced into the air electrode 4 of each cell in the same way as the fuel, and after passing through the electrolyte plate 3 and exchanging ions with the fuel electrode 2, it is oxidized and removed. It is discharged to the Roman Manifold 10. The exhaust oxidant recovered by the oxidation removal manifold 10 is discharged to the outside of the pressure vessel 13 through an oxidant discharge pipe 17. The stacked battery is held by applying pressure to the end plates 12 which are sandwiched between the upper and lower sides by the tie bolts 11. If the pressure difference between the fuel and oxidizer is large, the electrolyte may flow out from the electrolyte plate 3, or in extreme cases, the fuel 5 or oxidizer 6 may cross over through the electrolyte plate 3. , causing damage to the electrolyte plate 3.

For this reason, it is necessary to keep the differential pressure between the two very small. Also,
The pressure vessel 13 is filled with an inert gas slightly higher than the pressure of the fuel 5 and oxidizer 6 to prevent the fuel 5 and oxidizer 6 from leaking and to maintain safety in the event of an accident.

By the way, fuel cells are ``gravity equipment''.

It is necessary to respond to load application requests with good responsiveness. The load fluctuation corresponds to changing the supply amount of the fuel 5 and the oxidizing agent 6. Fuel 5 and 1R agent 6
Changes in the supply voltage of t may increase the pressure difference between the two or cause fluctuations. For this reason, for example, JP-A-57-2
A control device such as No. 3475 that constantly maintains these differential pressures at a very small level is provided.

However, these devices detect the pressure of the fuel 5 and the oxidizing agent 6, or the differential pressure therebetween, and the control device operates the valves for adjusting the fuel and oxidizer based on the detected signal. This has the disadvantage that it takes time to control and is difficult to follow sudden pressure fluctuations. Furthermore, since these devices are assumed to be installed outside the pressure vessel, it has been impossible to directly control the internal pressures of the fuel and oxidizer manifolds, which greatly affect the differential pressure between the electrodes.

[Purpose of the invention]

The purpose of the present invention is to constantly minimize the difference between the pressure on the fuel electrode side and the pressure on the air electrode side of a fuel cell, and to maintain a safe and reliable system even with changes in the supply amount of fuel and oxidizer due to load fluctuations. The objective is to provide a fuel cell with high performance.

[Summary of the invention]

The present invention focuses on the fact that in a fuel cell stack, the space between the pressure vessel and the manifold is filled with an inert gas close to the internal pressure of the manifold. In order to keep the differential pressure between the hold and the inert gas constant, a part of the manifold is made of an elastic material to have a variable volume, and the pressure inside and outside the manifold is balanced. .

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

FIG. 3 is a plan view showing an embodiment of the present invention. Third
In the figure, components opposite to those shown in FIG. 2 are given the same reference numerals and will be explained. In FIG. 3, the stacked battery is composed of a fuel electrode 2, an air electrode 4, etc., and on the side thereof, a fuel manifold 7, a fuel outlet manifold 8, an oxidizer manifold 9. An oxidizing agent output manifold 10 is arranged. These points are similar to the conventional example. In addition, fuel man romanifold 7
A has a fuel supply pipe 14, a fuel romanifold 8 has a fuel discharge pipe 15, an oxidizer type romanifold 9A has an oxidizer supply pipe 16, and an oxidizer outlet manifold 10 has an oxidizer discharge pipe 17. The laminated battery is surrounded by a pressure vessel 13, and an inert gas supply pipe 19 and an inert gas discharge pipe 20 are connected to the pressure vessel. These points are also similar to the conventional example. This embodiment differs from the conventional example in that an elastic body 18 is attached to each of the fuel manifold 7A and the oxidizer manifold 9A to form variable volume bodies.

The operation of the embodiment having such a configuration will be explained.

The fuel 5 is supplied to the fuel manifold 7A from the fuel supply pipe 14, passes through the fuel electrode 2, and is discharged through the fuel manifold 8 and the fuel discharge pipe 15. The oxidizing agent 6 is
The oxidizing agent is supplied from the oxidizing agent supply pipe 16 to the oxidizing romanifold 9A, and passes through the air electrode 4 to the oxidizing romanifold 1.
0, is discharged through the oxidizer discharge pipe 17.

Here, if the supply pressure of the fuel or oxidizer changes for some reason, the internal pressure of the fuel and oxidizer type manifolds 7A and 9A will change.

The elastic bodies 18 are deformed to cause a change in volume. As a result, the inert gas pressure inside the pressure vessel 13,
The gas pressures in manifolds 7A and QA will be automatically balanced.

According to this embodiment, high reliability can be maintained because devices such as sensors, control devices, and actuators are not required.

FIG. 4 is a plan view showing another embodiment of the present invention.

The difference between the embodiment shown in FIG. 4 and the embodiment shown in FIG. 3 is that a part of the fuel quantity Romanifold 8A and the oxidation creation Romanifold IOA includes a fuel manifold 7A and a pregelatinizing agent manifold. Elastic body 18 similar to 9A
The point is that a variable volume body is constructed by attaching the . Here, each elastic body 18 is adjusted in advance so that the internal pressure of the pressure vessel and the internal pressure of each manifold 7A, 8A, 9A, and IOA are balanced.

In this embodiment, in addition to controlling the fuel electrode and air electrode inlet pressures, it is also possible to control the fuel electrode and air electrode outlet pressures, so that the differential pressure between the fuel electrode and the air electrode can be further reduced.

FIG. 5 is a plan view showing still another embodiment of the present invention. The embodiment shown in FIG. 5 differs from the embodiment shown in FIG. 3 in the manifold 7B.

The elastic force of the elastic body 18 of 9B is made small, and the auxiliary elastic body 22 is attached to the manifold.

In this embodiment, since the elastic body 22 that balances the internal pressure of the manifold and the internal pressure of the pressure vessel 13 in advance can be provided separately from the manifold, initial settings can be made easily.

By installing an elastic body on the manifold and using a damper, it is possible to operate more stably.

In this embodiment, excessive movement of the manifold can be prevented and stable differential pressure control can be performed.

〔Effect of the invention〕

As described above, according to the present invention, the pressure difference between the pressure on the sound electrode side and the air electrode side can always be minimized using a manifold with variable volume, so it is safe even if sudden changes in pressure occur. This also has the effect of allowing highly reliable operation.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the basic components of a fuel cell, FIG. 2 is a perspective view showing a stack configuration of the fuel cell, FIG. 3 is a plan view showing an embodiment of the present invention, and FIG. FIG. 5 is a plan view showing an example of the same location. 2... Fuel electrode, 3... Electrolyte plate, 4... Air electrode,
7, 8...Fuel manifold, 9.10...1.
ff Curing agent manifold, 13...pressure vessel, 18
...Elastic body.

Claims (1)

[Claims] 1. A fuel electrode is provided on one surface of an electrolyte plate and an oxidation electrode is provided on the other surface, and cell units formed by sandwiching these with separators are stacked to form a stacked battery, and each side of the stacked battery is A manifold is disposed in the manifold, a fuel supply pipe, a discharge pipe, an oxidizer supply pipe, and a discharge pipe are respectively connected to the manifold, and the stacked battery is housed in a pressure vessel filled with an inert gas. 1. A fuel cell characterized in that at least a fuel and oxidant supply side manifold is a variable volume body formed using an elastic body in part.