JPS62262373A - Electrolyte feeding device for fuel cell - Google Patents

Abstract

PURPOSE:To eliminate a leakage through a small cutting or crack in the section of partition plates, and to improve the reliability and safety of electrolyte feeding, by linking the electrolyte storage grooves of neighboring gas partition plates with pipes set or screwed to penetrating holes. CONSTITUTION:At an end of electrolyte storage grooves 3 of partition plates 2 and 20, penetrating holes 4'and 4' are formed, in which fluorine resin pipes 8 and 8 with outside screws are screwed up. At the sealing surfaces between the neighboring partition plates, a pair of shims 9 and 10, and a carbon matrix 11 are placed, and each pipe 8 forms a linking route through the permeable holes of the shims 9 and 10, and of the matrix 11, up to the elctrolyte storage grooves 3 at the down stream side. At the shim 10 contacting to the electrolyte storage grooves 3, a slot-form cutting 12 is furnished, and the electrolyte storage grooves 3 oppose to the periphery of the carbon matrix 11 through the slot-form cutting 12. When the matrix is dried and necessary to feed the electrolyte, the electrolyte is fed from an external feeding pipe 13, and stored one by one in the storage grooves 3 of the partition plates through the pipes 8. The electrolyte in the storage grooves 3 is impregnated to the carbon matrix 11 through the slit-form cutting 12 of the shim 10.

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to a fluid replacement device for a fuel cell.

(o) In conventional fuel cells, the phosphoric acid electrolyte is held in a matrix interposed between the fuel electrode and the air bridge, but during cell operation, the matrix is dried by the high-temperature reaction gases flowing through various back surfaces. This is one of the causes of deterioration in battery performance. Therefore, a method is adopted in which an electrolytic solution storage section is provided in the 4/Ih and the electrolytic solution is supplied to the IJ from the outside via this storage section.

Figure 3 shows a battery stack (S) equipped with such a fluid replacement device.
), each carbonaceous gas separation plate (2) interposed between cells fl1 has a liquid storage groove (
3), and these liquid storage grooves (3) are communicated through a through hole (4) to form a serial liquid replacement path.

In the carbonaceous gas separation plate (2), the storage liquid 14 (31
and each reaction gas supply groove (51 (61 is formed when creating the separation plate by hot pressing, while the through hole (4)
is formed by drilling after the separation plate is completed.

Therefore, when the electrolytic solution flows through the through hole (4), there is a risk that the electrolyte will leak to the outside if a minute scratch or crack is created in the cross section of the separator plate. In particular, the cooling plate/gas separation plate shown in Figures 4 and 5 (2& is the fuel side half plate (2+)
and air side half plate R) and connect the cooling gas passage (
7), there were problems such as the risk of liquid leakage from the adhesive portion facing the through hole (4).

el Problems to be Solved by the Invention The present invention solves the problems mentioned above during fluid replacement and improves the reliability and safety of fluid replacement.

B) Means for Solving Problems This invention provides an acid-resistant through-hole between the liquid storage grooves formed on each sealing surface of the coal・It should be a communication path formed by fitting or screwing a heat-resistant pipe.

(E) Function This invention prevents liquid leakage to the outside during liquid replacement, especially from the adhesive surface of the gas separation plate that also serves as a cooling plate, and provides smooth flow of the liquid, thereby improving reliability and ty. Sexuality is improved.

(F) Embodiment An embodiment of the present invention will be explained with reference to the drawings, and the corresponding parts are designated with the same number 6 as in FIGS. 3 to 5 above.

Figure 1 is a partial view of the battery stack (S) along the fluid replacement path (X-Y line in Figure 4), with stacked gas separation plates (
2) and a gas separation plate S that also serves as a cooling plate are shown.

These separation plates + 2K)cX One end of the liquid storage groove (3)
Threaded fluororesin pipes (8081 are each screwed on. This pipe has an inner diameter of 5W1 and an outer diameter of 7 to 8 m,
In the case of the gas separation plate G that also serves as a cooling plate, it also serves as a connecting member with the fuel side half plate (2+) and the air side half plate (2+).

Also, the through hole should not be a screw hole (the pipe may be tightly fitted).

A pair of shims (9) αω and a carbon matrix αD are interposed between the sealing surfaces between adjacent distribution plates, and each pipe (8) is connected to the downstream storage via the shims (9) αω and the through holes in the matrix αD. A communication path leading to the liquid groove (3) is formed.

The shim side in contact with each of the liquid storage grooves (3) has a slit-like notch (2), and each of the liquid storage grooves (3) faces the periphery of the carbon matrix αD via the slit-like notch.

When the IJ hook is dry and requires fluid replacement, the electrolyte can be injected from the external supply pipe 03 and the electrolyte will flow through the liquid storage groove of each separation plate (
3) through each pipe (8). In this case, the water repellency of the pipe (8) allows for smooth flow and there is no risk of leakage. The electrolyte in each liquid storage groove (3) is
The liquid is impregnated into the carbon matrix (111) through the slit-shaped notch of the shim U■, and also transferred to the SiC matrix coated on the air electrode (not shown), completing the liquid replacement.

(Ton effect) According to the present invention, the storage 1 & grooves of the adjacent gas separation plates are communicated with each other by a pipe fitted or screwed into the through hole. Particularly in the case of a two-split cooling plate that also serves as a gas component^1 plate, this prevents liquid from leaking from the joint surface to the outside, and the pipe also serves as a joining member for the split plates, helping to improve strength. Furthermore, when the pipe is made of fluororesin, its water repellency allows for smooth liquid flow and eliminates the risk of liquid clogging.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the main parts of a battery stack equipped with the device of the present invention, Fig. 2 is a front view of the pipes constituting the same device, Fig. 3 is a schematic diagram of a stack equipped with a fluid replacement path, and Fig. 4 is a conventional device. Fig. 5 is a sectional view of the main part taken along the X-Y line in Fig. 4. Separation plate, (3)・
...Liquid storage groove, (4)...Threaded through hole, (8)...
・Pipe, +91, αω...Shim, (Ill...
・Sword - Bon Matrix, Shi...Slit-like notch.

Claims (3)

[Claims] (1) In a battery stack in which a large number of cells and carbonaceous gas separation plates are stacked alternately and a gas separation plate that also serves as a cooling plate is interposed every few cells, the gas separation plates that are adjacent to each other through the cells are A fluid replacement device for a fuel cell, characterized in that fluid storage grooves formed on each sealing surface are communicated by a heat-resistant and acid-resistant pipe fitted into a through hole. (2) The liquid replacement device for a fuel cell according to claim 1, wherein the through hole is a screw hole, and the pipe is screwed into the through hole. (3) The liquid replacement device for a fuel cell according to claim 1 or 2, wherein the pipe is made of fluororesin.