JPS59217959A - Device for externally supplying electrolyte for fuel cell - Google Patents

Abstract

PURPOSE:To facilitate supply of electrolyte by installing a porous flexible member in such a manner as to touch a cathode member closely and installing a cartridge-type external reservoir which can be freely attached and detached by means of an insertion plate. CONSTITUTION:On both surfaces of each unit cell consisting of an electrolyte matrix 6, an anode member 5 and a cathode member 7, gas-separating plates 8 having grooves for gas flow paths are installed, thereby constituting a fuel cell. A concave for an external reservoir is provided on the surface of the gas separator 8 having no gas flow paths. In this concave, a cartridge-type external reservoir 9 having a concave 9a in which a porous flexible member 10 closely touching the cathode member 7 is installed, is placed. The external reservoir 9 is held in a desired position by means of an insertion plate 11. Therefore, very easy supply of electrolyte is secured by inserting a new reservoir 9 after extracting the insertion plate 11 and the reservoir 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolyte external replenishment device for a fuel cell.

As is well known, a fuel cell consists of fuel electrodes (
It is a type of power generation device that is operated by disposing an electrolyte matrix holding an electrolyte between an anode (anode) and an oxidant electrode (cathode), and supplying fuel gas and oxidant gas to the anode and cathode, respectively. Fuel cells are classified into alkaline type, phosphoric acid type, molten carbonate type 1, etc. depending on the type of electrolyte used, and these are equipped with a mechanism for controlling the absolute amount of electrolyte. One such method is to process a part of the gas separation plate to form an external electrolyte replenishment device (hereinafter referred to as an external reservoir).

This method has been conventionally used mainly in phosphoric acid fuel cells, which are currently considered to be the most advanced in development, particularly in the lipped separator type in which the gas separation plate is provided with reaction gas supply grooves. This method will be explained below using figures.

Figure 1 is a plan view of a gas separation plate with an external reservoir.
The gas separation plate has a convex portion l of the concave-convex gas flow path portion and a concave portion λ of the concave-convex gas flow path portion in parallel, and an external reservoir 3 is placed in the concave portion. is a side view seen from the ad side of FIG. 1, and FIG. 3 is a side view seen from the dc side, each showing an enlarged portion of the external reservoir 30. In the figure, S is a cathode member, O is an electrolyte matrix, 7 is an anode member, and g is a gas separation plate.

The external reservoir is lined with a porous member for storing electrolyte, and is connected by the electrolyte to the electrolyte matrix B through a wet seal portion of the anode member. Therefore, if there is a shortage of electrolyte in the electrolyte matrix B, electrolyte is replenished from the external reservoir to the electrolyte matrix, and conversely, if there is an excess of electrolyte IJ Lux electrolyte, the surplus is transferred to the external reservoir. It will be done. If there is a shortage of electrolyte that cannot be covered by the external reservoir, the electrolyte supply hole is opened and electrolyte is supplied from the outside. In this way, the external reservoir is a mechanism provided for the purpose of always keeping the absolute amount of electrolyte held in the electrolyte matrix at an optimum level and enabling control from the outside.

However, such external reservoir mechanisms that have been used in the past have some drawbacks.The reason is that when replenishing electrolyte from the outside using the electrolyte supply hole, it is necessary to provide sufficient fluidity to the electrolyte. ℃ using external auxiliary equipment.
It is necessary to preheat the electrolyte, which requires considerable effort and time to replenish the electrolyte, and it is difficult to grasp the appropriate amount of replenishment. For example, an external reservoir cannot be provided on the back side of the CD side (the cand side in FIG. 2).

The present invention has been made in order to eliminate the drawbacks of the conventional devices as described above, and an object of the present invention is to provide an external electrolyte replenishment device in which the external reservoir is of a cartridge type and can be freely replaced from the outside, making it easy to perform electrolyte replenishment work. With the aim of It is designed so that it can be performed from the side.

An embodiment of the present invention will be described below with reference to the drawings. qth
Figures 1 and 3 are side views of this embodiment, and correspond to Figures λ and 3 of the prior art, respectively. The cartridge type external server board has a recess as shown in Figure 6. a, and a flexible porous member 10 that tightly contacts the cathode member is inserted and housed in this recess 9a. The external reservoir board is held in position against the battery by an insert plate //. When replenishing electrolyte, first pull out the insertion plate // and then insert the cartridge type external reservoir. Push down and pull this out, so the reservade is a protruding part? b, and the insert plate // has approximately the same length as the reservoir t.

External reservoir at this point? It is possible to determine the amount of electrolyte to be replenished from the amount of electrolyte remaining.

Based on this determination, the porous member of a new cartridge with an appropriate volume is filled with electrolyte and inserted. Finally, press the cartridge upwards and insert the insertion plate to complete the replenishment process. This series of operations consists of four parts of various shapes as shown in Fig. 6, Fig. 7, Fig. 3, and Fig. 9. If a reservoir with a is prepared, it can be selected as needed, and electrolyte can be easily replenished in a very short period of time.

Furthermore, according to the present invention, an external reservoir can also be provided on the back surface of the gas separation plate. In this case, during assembly, instead of the cartridge type external reservoir 9, a pseudo cartridge lλ is inserted as shown in Fig. 1θ, and after assembly, it is replaced with the cartridge type external reservoir. If external reservoirs are provided at both ends of the anode and cathode in one cell in this way, the effect of the external reservoir can be further enhanced.

! In addition, in the part where there are no unevenness of the flow path on either the front or back of the gas separation plate, insert an IJ type external reservoir with one insertion plate on the front and back of the waste separation plate as shown in Figure 1. At the same time, the electrolytes of the upper and lower cells can be managed.

Furthermore, if a heater 13 is built into the insertion plate as shown in Fig. 12, it becomes possible to locally heat the external reservoir 9, and by utilizing the temperature difference with the fuel tank body, the electrolyte M) It is possible to control the impregnation rate of IJ Lux, thereby ensuring replenishment of electrolyte.

In the above embodiments, a separator type with ribs was described, but an electrode type with ribs that forms a reaction gas flow path in the electrode member may also be used. In this case, a similar mechanism is provided on a flat gas separation plate. It has a similar effect. In addition, even for molten carbonate type electrolytes, for which external reservoirs have not been used so far, the external reservoir of the present invention allows sufficient electrolyte management.

As described above, according to the present invention, by using a cartridge type external reservoir, electrolyte replenishment work can be carried out easily and appropriately in a short time. Further, it becomes possible to provide the gas separation plate on either the front or back side.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a waste separation plate showing the position of a conventional external reservoir, FIGS. 2 and 3 are side views of a unit cell showing a conventional external reservoir, and FIGS. A side view of a cell showing a cartridge-type external reservoir according to an embodiment of an electrolyte external replenishment device, FIG. 6 is a perspective view of the cartridge-type external reservoir, and FIGS. 7, S, and 9 are cartridge-type external reservoirs. 10 and 11 are side views of single cells according to other embodiments, and FIG. 12 is a plan view of an insertion plate containing a heater. l... Convex part of the gas flow path section, λ... Four parts of the gas flow path section, 3
・・External reservoir, ・・・External electrolyte supply hole, S・・Cathode member, 6・・Electrolyte matrix, 7・・・Anode member, g・・Gas separation plate, 9・・Cartridge type external reservoir, 10・・Porous material, ll...insertion plate, /2
...pseudo cartridge, 13...heater. In the figures, the same reference numerals indicate the same or equivalent parts. Agent Masu Oiwa Yuen 1 illustration 2 illustration M 3 illustration 4 illustration P? ) 5 figures 6 figures Most 7 figures Most 8 figures 9 figures v) 10 figures Foot 12 figures Leather 11 figures

Claims (1)

[Claims] A cartridge-type external reservoir that houses a flexible porous member that can be brought into close contact with the cathode part of a fuel cell that is incorporated into a gas separation plate; and an insertion plate for holding an external reservoir so as to hold an external reservoir.