JP3244779B2 - Fuel cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell, and more particularly to a fuel cell in which a seal for a fuel gas or an oxidizing gas is improved.

[0002]

2. Description of the Related Art Conventionally, fuel cell seals of the type in which separators are attached to both sides of a fuel cell power generator (cell) are:
This has been done by bonding or applying a seal tape, a sealant, or an adhesive to the cell end. Therefore, when stacking cells to form a stack, the cells and the separator must be stacked while applying a sealant, an adhesive, and the like.
Productivity was low.

[0003] However, even if such measures are taken, hydrogen, which is the fuel of the fuel cell, tends to leak. When the pressurization operation is performed, for example, the fuel cell body (stack) is placed in a pressure vessel, and the hydrogen pressure in the stack and the pressure of the inert gas outside the stack are made equal with an inert gas such as nitrogen.
A method to prevent hydrogen leakage was taken.

[0004]

By the way, in a fuel cell using hydrogen, which has a danger of explosion when leaking, it is important to improve gas tightness. The present invention has been made in consideration of such circumstances, and has as its object to provide a fuel cell that can reliably and easily perform gas sealing.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a polymer
A fuel cell generator having an on-electrolyte membrane sandwiched between two gas diffusion electrodes ; and a fuel cell generator surrounding the fuel cell generator and
Seal placed in the area of the pond power generator requiring airtightness
And separators provided on both sides of the fuel cell power generator and the sealing material , respectively. A fuel gas supply groove and an oxidant gas supply groove are provided on both surfaces of the separator, respectively, and the seal is provided. Formed by material and separator
Having a hermetically sealed portion, and sealing the separator in the hermetically sealed portion.
Provided Lumpur agent groove, the sealant groove is a fuel cell characterized by being sealed by a sealing agent liquid.

[0006]

According to the present invention, a fuel cell power generator (cell) is provided.
By providing a means for sealing the fuel gas supply groove and the oxidizing gas supply groove respectively in the separator sandwiching the gasket from both sides, specifically, a sealant groove, a liquid sealant, etc., the fuel gas leakage is reduced from the conventional one. This can be significantly prevented. Also, assembly and construction can be easily performed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) Reference is made to FIGS. Here, FIG. 1 is an exploded perspective view of the fuel cell before assembly, FIG. 2 is an exploded perspective view of the stack, and FIG. 3 is a vertical sectional view of the sealing surface of FIG.

[0008] Reference numeral 1 in the figure denotes a fuel cell power generator (cell). The cell 1 includes a cell part 2 and a sealing material 3 joined to the cell part 2. Here, as shown in FIG. 3 , the cell section 2 includes an electrolyte membrane 4 and the electrolyte membrane 4.
And gas diffusion electrodes 5 disposed on both sides of the gas diffusion electrodes. The main surface of the sealing material 3 is used as a sealing surface. The connection between the cell portion 2 and the sealing material 3 has been made before the stack assembly, and there is no need to use an adhesive or a sealant at the time of stack assembly. A sealing material passage hole 6 is provided at a corner of the sealing material 3 of the cell 1.

The two main surfaces of the cell 1 are sandwiched between separators 7. An oxidizing gas supply groove 8 is provided at the center of one main surface of the separator 7, and a fuel gas supply groove 9 intersects the oxidizing gas supply groove 8 at the center of the other main surface. Is provided. A sealant groove for holding a liquid is provided in a portion of the separator 7 which is in contact with the sealing surface.
10 is provided, and a gas leakage can be prevented by filling a liquid sealing agent from the sealing agent supply hole 11 after the stack assembly is completed. FIG.
Reference numeral 11a denotes a sealant supply hole (for the back surface).

The fuel cell having such a configuration is assembled as shown in FIG. 2 to form a stack. In FIG. 2, reference numeral 12 denotes a stack in which a plurality of cells 1 and separators 3 are alternately stacked. The stack 12 is surrounded by a manifold 13 on the side wall and upper and lower end flanges 14. The end flange 14 is provided with a sealant inlet 15.

In the fuel cell according to the first embodiment, as shown in FIGS. 1 and 3, a sealant groove 10 for retaining a liquid is provided in a separator 7 which is in contact with a sealing material 3 around a cell 1, and after a stack assembly is completed. Since the liquid sealant is filled from the sealant supply hole 11, leakage of the fuel gas can be significantly prevented as compared with the related art. Therefore, the mixing of the fuel gas and the oxidizing gas in the manifold 13 after the stack assembly is completed can be made extremely small (20 ppm). (Embodiment 2) Referring to FIGS. Here, FIG. 1 is an exploded perspective view of the fuel cell before assembly, and FIG. 2 is an exploded perspective view of the stack.

Reference numeral 21 in the drawing denotes a cell comprising a cell portion 22 and a sealing member 23 around the cell portion. A sealant passage hole 24 is provided in a corner portion of the sealant 23 facing the oblique direction. On the opposite side of the cell 21, packing
25 are provided.

On both main surfaces of the cell 21 including the packing 25, an internal header type separator 26 sandwiching the cell 21 is provided.
Is arranged. A fuel gas supply groove 27 is formed in the center of one main surface of the separator 26, and a sealant groove 28 is formed so as to surround the fuel gas supply groove 27. An oxidizing gas supply groove 29 is formed at the center of the other main surface of the separator 26, and a sealing agent groove is formed so as to surround the oxidizing gas supply groove 29.

In the separator 26 near the sealant groove 28, a sealant supply hole 30 and a sealant discharge port 31 are provided diagonally opposite to each other. Further, the separator 26
A fuel gas supply port 32, a cooling water discharge port 33, and an oxidizing gas supply port 34 are provided in a line at the upper end of the separator 26, respectively. An opening 36 and a fuel gas outlet 37 are provided in a line.

As shown in FIG. 5, a plurality of such fuel cells are stacked, and a stack is formed by flanges 38, 39 on both sides and bolts 40 connecting the flanges 38, 39 to each other. In FIG. 5, reference numeral 41 denotes a sealant inlet provided on the flange 38, and reference numeral 42 denotes a sealant outlet.

According to the fuel cell of the second embodiment, the sealant groove 28 is formed on one main surface of the separator 26 so as to surround the fuel gas supply groove 27, and the other main surface of the separator 26 is oxidized. Since the sealant groove 28 is formed so as to surround the agent gas supply groove 29, similar to the first embodiment,
Fuel gas leakage can be significantly reduced as compared with the conventional case. (Embodiment 3) Referring to FIG. Example 3 shows a case in which water is used as a liquid sealant. 1 and 3 are denoted by the same reference numerals and description thereof will be omitted.

Reference numeral 51 in the drawing denotes a claw provided at a predetermined position on the separator 7. This is because when a liquid having low viscosity such as water is used as the liquid sealant, it is necessary to hold the liquid seal. In addition, the claw needs to be held similarly when the liquid sealant is pressurized when the gas pressure to be hermetically sealed is relatively high (about 3 atm to 18 atm).

By the way, using the inner header type separator shown in FIGS. 4 and 5 and the groove structure shown in FIG. 6, circulating water for cooling the cell is further introduced from the sealant supply hole, and is further discharged from the sealant discharge hole. The cooling water system was piped so as to be discharged (Fig. 7
reference). The number 52 in the figure is the cooling water circulation pump 5.
3. Cooling water line with needle valve 54 interposed, numbering
Reference numeral 55 denotes a seal water supply line, reference numeral 56 denotes a cooling water drain line, and reference numeral 57 denotes a seal water drain line. When a pump having a discharge pressure of up to 7 kgf / cm ² was used as the pump 52 and a leak test was performed up to 5.0 atg,
Airtightness was good, and good results were obtained without leakage of cooling water.

In the third embodiment, the case where water is used as the liquid sealant has been described. However, the present invention is not limited to this.
For example, cooling water for the cell, water for humidifying the polymer ion exchange membrane, or the like may be used.

[0020]

As described in detail above, according to the present invention,
The gas tightness is improved, the workability at the time of stack assembly can be improved, and the force applied by the flanges and bolts, which was performed to obtain gas tightness, is reduced by 1 /
It is possible to provide a fuel cell that can be reduced to about five.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a fuel cell according to Embodiment 1 of the present invention.

FIG. 2 is an exploded perspective view of a stack formed by stacking a plurality of the fuel cells of FIG.

FIG. 3 is a vertical sectional view of the sealing surface of FIG. 1;

FIG. 4 is an exploded perspective view showing a fuel cell according to Embodiment 2 of the present invention.

FIG. 5 is a perspective view of a stack formed by stacking a plurality of fuel cells of FIG. 4 using flanges and bolts.

FIG. 6 is a sectional view of a main part of a fuel cell according to Embodiment 3 of the present invention.

7 uses the internal header type separator shown in FIGS. 4 and 5 and the groove structure shown in FIG. 6, and introduces circulating water for cooling the cell from the sealant supply hole and discharges it from the sealant discharge hole. FIG. 1 is a diagram in which a cooling water system is piped in such a manner as to perform the following.

[Explanation of symbols]

1,21 ... cell, 2,22 ... cell part, 3,23 ... seal material, 4
... electrolyte membrane, 5 ... gas diffusion electrode, 6,24 ... sealant passage hole, 7,26 ... separator, 8,29 ... oxidant gas supply groove,
9, 27 ... fuel gas supply groove, 10, 28 ... sealant groove, 11, 11
a, 30: sealant supply hole, 12: stack, 13: manifold, 14: end flange, 15: sealant injection hole, 25:
Packing, 31… Sealant outlet, 32… Fuel gas inlet, 33… Cooling water outlet, 34… Oxidant gas inlet, 35… Oxidant outlet, 36… Cooling water inlet, 37… Fuel gas exhaust exit,
38, 39… Flange, 40… Bolt, 41… Sealant inlet,
42 ... sealant outlet, 51 ... claw.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Nagao Kurusu 1-1, Akunouracho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Inventor Satoshi Uchida 1-1, Akunouracho Nagasaki City, Nagasaki Prefecture Mitsubishi (56) References JP-A-62-73574 (JP, A) JP-A-59-186272 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8/00-8/24

Claims (1)

(57) [Claims] 1. A polymer-type ionic electrolyte membrane formed by two gas expansions.
A fuel cell power generator sandwiched between diffused electrodes and airtightness around the fuel cell power generator and the fuel cell power generator are required.
A sealing material disposed at a portion where the fuel cell
And a separator provided on both sides of the sealing material, respectively , a fuel gas supply groove and an oxidizing gas supply groove are provided on both surfaces of the separator, respectively, and the sealing material and the separator are provided.
Having an airtight portion formed by the airtight portion,
A fuel cell , wherein a sealant groove is provided in a separator, and the sealant groove is sealed with a liquid sealant.