JPH09115538A - Humidification quantity control device for solid polymer electrolytic film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the electrolytic film to be humidified certainly and effectively with a simple constitution. SOLUTION: A humidification quantity control device 60 is provided with a water permeable duct line 26 prepared inside of an electrolytic film 12, a water introduction means 56 which introduces water for humidification from a water supply passage 52 formed in a first manifold plate 46 to the water permeable duct line 26, and projection parts 54 which are provided in the first manifold plate 46 and can blockade the water permeable duct line 26 by being swelled, resulting from the electrolytic film 12 being humidified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid polymer electrolyte membrane humidification amount control device for humidifying a solid polymer electrolyte membrane constituting a fuel cell.

[0002]

2. Description of the Related Art A solid polymer electrolyte membrane fuel cell is a fuel cell structure (unit cell, which is composed of an electrolyte composed of a polymer ion exchange membrane, and a catalyst electrode and a porous carbon electrode arranged on both sides of the electrolyte. ) Is sandwiched by separators and a plurality of layers are laminated.

In this type of fuel cell, hydrogen (fuel gas) supplied to the anode electrode is hydrogen-ionized on the catalyst electrode and moves to the cathode electrode side through the appropriately humidified electrolyte. The electrons generated during that time are taken out to an external circuit and used as DC electric energy. Since an oxidant gas, for example, oxygen gas or air is supplied to the cathode side electrode, the hydrogen ions, the electrons, and oxygen react at the cathode side electrode to generate water.

By the way, the electrolyte composed of the polymer ion exchange membrane needs to be sufficiently humidified in order to maintain the ion permeability. For this reason, for example, Japanese Patent Application Laid-Open
As disclosed in Japanese Unexamined Patent Publication No. 96182, a technique for obtaining a solid polymer electrolyte membrane having a narrow passage by embedding a water-soluble thread in a solid polymer electrolyte membrane for molding, and then eluting and removing the thread. It has been known.

[0005]

However, in the above-mentioned prior art, in order to adjust the humidification amount of the solid polymer electrolyte membrane, a pump for changing the water supply pressure is provided outside the fuel cell. The pump needs to be controlled. As a result, it has been pointed out that the humidification amount control device provided with the pump becomes large in size and the control of the pump becomes complicated.

The present invention solves this kind of problem, and an object of the present invention is to provide a humidification amount control device for a solid polymer electrolyte membrane which has a simple structure and which can surely and effectively humidify an electrolyte. And

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention is to supply humidifying water from a water supply passage formed in a separator to a water passage of a solid polymer electrolyte membrane. The solid polymer electrolyte membrane diffuses and permeates into the solid polymer electrolyte membrane to be directly humidified. Then, when the solid polymer electrolyte membrane is humidified and swells, the water passage of the solid polymer electrolyte membrane or the water supply passage of the separator is closed through the operating part, and the humidification amount of the solid polymer electrolyte membrane is reduced. It Thereby, the humidification amount of the solid polymer electrolyte membrane can be automatically and accurately adjusted with a simple configuration.

The water passage is composed of a water-permeable pipe embedded in the solid polymer electrolyte membrane, and a needle member constituting water introducing means is inserted into this pipe from the water supply passage. Since this pipe is hollow and has a porous tip, the supply of humidifying water to the water passage is smoothly performed.

Further, the actuating portion may be provided with a protrusion provided inside the solid polymer electrolyte membrane and protruding toward the water passage, or an opening for communicating the water supply passage with the solid polymer electrolyte membrane. . This simplifies the structure of the operating unit all at once, and eliminates the need to install equipment outside the fuel cell.

[0010]

1 to 3, reference numeral 1
Reference numeral 0 indicates a fuel cell incorporating the humidification amount control device according to the first embodiment. This fuel cell 10 has a fuel cell structure 1 in which an air electrode (cathode-side electrode) 14 and a hydrogen electrode (anode-side electrode) 16 are provided opposite to each other with a solid polymer electrolyte membrane 12 interposed therebetween.
8 and a separator 2 for sandwiching the fuel cell structure 18
0. Fuel cell structure 18 and separator 20
Are integrally fixed by a pair of end plates 22a, 22b and a plurality of tie rods 24.

The inside of the electrolyte membrane 12 is shown in FIGS.
As shown in FIG. 5, a plurality of water permeable conduits (water passages) 26 that are vertically spaced apart from each other by a predetermined distance and extend in the vertical direction are embedded in parallel with each other. This water-permeable conduit 26 is made of tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polychlorotrifluoroethylene (PCTFE) or polyvinylidene fluoride (PVD).
Fluorine resin such as F), polyvinyl chloride polymer alloy (PVC / CPE), ethylene / propylene rubber (EP
R & EPDM), Millable Silicone Rubber (HT
V), or a fluorine-based thermoplastic elastomer (TPF)
And the like. Instead of the water permeable conduit 26, a resin tube of this type may be embedded inside the electrolyte membrane 12 and then eluted to directly form the water passage.

As shown in FIG. 2, a cooling water discharge hole 12a, an oxidant gas introduction hole 12b, and a fuel gas introduction hole 12c are provided on the upper side of the electrolyte membrane 12, while A fuel gas discharge hole 12d, an oxidant gas discharge hole 12e, and a cooling water introduction hole 12f are provided on the lower side.

On both sides of the electrolyte membrane 12, the first and second electrodes are formed.
Gaskets 30, 32 are provided. First gasket 3
0 has a large opening 34 for accommodating the hydrogen electrode 16, and the second gasket 32 has a large opening 36 for accommodating the air electrode 14. On the upper end side of the first and second gaskets 30 and 32, the cooling water discharge hole 3 is formed.
0a, 32a, oxidant gas introduction holes 30b, 32b, and fuel gas introduction holes 30c, 32c are provided, while the fuel gas discharge hole 30 is provided on one end side of the lower portion thereof.
d and 32d, oxidant gas discharge holes 30e and 32e, and cooling water introduction holes 30f and 32f are provided. On the lower side of the first gasket 30, a plurality of holes 38a are formed corresponding to the lower end positions of the water permeable conduits 26 of the electrolyte membrane 12, and on the upper side thereof, the water permeable tubes are formed. Road 2
A plurality of holes 38b are formed corresponding to the upper end position of 6.

The separator 20 comprises a first separator portion 40 which abuts on the hydrogen electrode 16 side and a second separator portion 42 which abuts on the air electrode 14 side. First separator section 40
Has a first manifold plate 46 and a fuel gas rectifying plate 50 that fits into a relatively large opening 48 formed in the first manifold plate 46 (see FIGS. 2 and 3).

The first manifold plate 46 is a rectangular flat plate made of dense carbon, and has a cooling water discharge hole portion 46a, an oxidant gas introduction hole portion 46b and a fuel gas introduction hole on the upper side thereof. A hole 46c is provided. On the lower side of the first manifold plate 46, a fuel gas discharge hole 46d is formed.
And hole 46e for discharging oxidant gas and hole 46 for introducing cooling water
f and are provided.

The holes 46c and 46d communicate with the opening 48 through the notches 47a and 47b formed in one surface (on the side of the hydrogen electrode 16) of the first manifold plate 46, while the holes 46a and 46f are connected to each other. , Communicates with the opening 48 via notches 47c and 47d formed on the other surface of the first manifold plate 46.

On the lower side surface of the first manifold plate 46,
A plurality of water supply passages 52 are formed corresponding to the water permeable conduits 26 provided in the electrolyte membrane 12 and are separated from each other by a predetermined distance. As shown in FIG. 4, the water supply passage 52 is formed on the lower side surface of the first manifold plate 46 and the first manifold plate 4
It is bent and formed so as to open to the lower end surface of 6. On the lower side surface of the first manifold plate 46, a protruding portion (actuating portion) 54 is formed so as to bulge above the end portion of each water supply passage 52 that opens in the horizontal direction.

A needle member 58, which constitutes the water introducing means 56, is fitted to the end of the water supply passage 52 that opens in the horizontal direction. The needle member 58 has a hollow shape and its tip is made porous. Water-permeable conduit 2 for electrolyte membrane 12
6, water supply passages 52, water introducing means 56 inserted into the water supply passages 52, and projections provided above the water supply passages 52 and corresponding to the water permeable conduits 26. 54 together constitute the humidification amount control device 60 according to the first embodiment.

As shown in FIG. 2, the first manifold plate 4
A water discharge path 62 is formed from the upper side surface to the upper end surface of 6, and a needle member 64 is fitted to the horizontal opening end of the water discharge path 62. Although not shown in the drawings, the vertical opening ends of the water supply paths 52 and the water discharge paths 62 are not shown.
The water supply tank and the water discharge tank are connected via a pipe or directly.

The fuel gas straightening plate 50 is made of a water-permeable carbon material. A plurality of protrusions 50a extending in the horizontal direction and arranged in a zigzag pattern are provided on one surface of the fuel gas flow straightening plate 50, and the protrusions 50a meander in the vertical direction. The first gas flow path 50b is formed. Similarly, on the other surface of the fuel gas rectifying plate 50, a plurality of protrusions 50c are provided in parallel with each other in the horizontal direction and in a staggered manner, and the same flow passage structure as the first gas flow passage 50b. The first cooling water flow path 50d having the above is formed.

The second separator portion 42 has a second manifold plate 66 and an oxidant gas rectifying plate 70 fitted in a relatively large opening 68 formed in the center of the second manifold plate 66. The second manifold plate 66 is the first
The manifold plate 46 has substantially the same structure, and a cooling water discharge hole 66a, an oxidant gas introduction hole 66b, and a fuel gas introduction hole 66c are provided on the upper side of the manifold plate 46, while the lower portion thereof is provided. A fuel gas discharge hole 66d, an oxidant gas discharge hole 66e, and a cooling water introduction hole 66f are provided on the side.

The holes 66a, 66f communicate with the opening 68 through the notches 72a, 72b formed in one surface (on the side of the first separator 40) of the second manifold plate 66, and the holes 66b, 66e. Is the second manifold plate 6
6 communicates with the opening 68 via notches 72c and 72d formed in the other surface of the plate 6.

The rectifying plate 70 for the oxidant gas is made of carbon, stainless steel, or a corrosion resistant conductive metal such as a nickel alloy such as Inconel (trademark), a conductive rubber or a conductive resin, and a combination thereof. Composed of materials. A second gas flow passage 70b is formed on one surface of the rectifying plate 70 for oxidant gas by a plurality of protrusions 70a extending in the horizontal direction and arranged in parallel and in a zigzag pattern. On the other surface of the rectifying plate 70 for oxidant gas,
Similarly, the second cooling water flow passage 70d is formed via the plurality of protrusions 70c that extend in the horizontal direction and are parallel to each other and are arranged in a staggered manner. The second gas flow channel 70b and the second cooling water flow channel 70d have the same flow channel structure and are set to flow directions opposite to each other.

The operation of the fuel cell 10 thus constructed will be described below in connection with the humidification amount control device 60 according to the first embodiment.

When the oxidant gas (oxygen gas or air) is supplied to the fuel cell 10, the oxidant gas is used to form the holes 46 of the first manifold plate 46 that form the first separator section 40.
b and the second manifold plate 66 constituting the second separator part 42, and is supplied to the hole 66b of the second manifold plate 66, and is introduced into the second gas flow passage 70b of the rectifying plate 70 for oxidant gas from the notch 72c of the hole 66b. (See FIG. 3). Therefore, the oxidant gas flows in the direction of gravity so as to meander along the second gas passage 70b, and the unused portion is discharged from the notch 72d to the hole 66e.

When the fuel gas (hydrogen gas) is supplied to the fuel cell 10, the fuel gas is supplied to the first manifold plate 46.
Hole portion 46c of the second manifold plate 66 and the hole portion 66 of the second manifold plate 66.
It is supplied to the first gas flow passage 50b of the fuel gas straightening plate 50 through the notch 47a communicating with the hole 46c. Therefore, the fuel gas flows in the gravity direction so as to meander along the first gas flow path 50b, and the unused portion is discharged from the hole 46d. As a result, the fuel gas is supplied to the hydrogen electrode 16 constituting the fuel cell structure 18 and the oxidant gas is supplied to the air electrode 14.

On the other hand, the cooling water supplied to the fuel cell 10 is supplied to the hole 46f of the first manifold plate 46,
A part of the first part of the fuel gas straightening plate 50 is provided from the notch 47d.
It is introduced into the cooling water channel 50d. Therefore, the cooling water does not have a gravity direction so as to meander between the first cooling water flow passage 50d of the fuel gas flow straightening plate 50 and the second cooling water flow passage 70d of the oxidant gas flow straightening plate 70. It flows in the opposite direction and is discharged to the hole 66a of the second manifold plate 66.

By the way, in the first embodiment, the amount of humidification of the electrolyte membrane 12 is automatically adjusted through the humidification amount controller 60. That is, as shown in FIGS. 4 and 5, needle members 58 and 64 are inserted into the water supply passage 52 and the water discharge passage 62 of the first manifold plate 46, respectively. The tips of the needle members 58, 64 are inserted into the electrolyte membrane 12 through the holes 38a, 38b formed in the first gasket 30, and enter the water permeable conduits 26 of the electrolyte membrane 12. To do. As a result, the water supply passage 52 communicates with the lower side of the water permeable conduit 26 via the needle member 58, while the upper side of the water permeable conduit 26 communicates with the water discharge passage 62 via the needle member 64. doing.

Therefore, when the humidifying water is supplied to the water supply passage 52, the humidifying water is, as shown by an arrow in FIG.
It is introduced from the inside of the needle member 58 to the lower side of each water permeable conduit 26 of the electrolyte membrane 12, penetrates through this water permeable conduit 26, diffuses and permeates into the inside of the electrolyte membrane 12, and the electrolyte membrane 12 Humidify.

When the electrolyte membrane 12 is directly humidified by the humidifying water, the electrolyte membrane 12 itself swells. At that time, the electrolyte membrane 12 includes the first and second separator portions 40, 42.
Is sandwiched by the first manifold plate 4
Reference numeral 6 denotes the electrolyte membrane 1 corresponding to each water permeable conduit 26.
A protrusion 54 that bulges toward the second side is formed. Therefore, when the electrolyte membrane 12 swells, the water-permeable conduit 26 is closed at the position corresponding to the protrusion 54, and the amount of humidifying water supplied into the electrolyte membrane 12 is limited.

As described above, in the first embodiment, the first manifold plate 46 is provided with the protrusions 54 as the operating portions corresponding to the respective water permeable conduits 26 in the electrolyte membrane 12, and The amount of humidifying water that directly humidifies the electrolyte membrane 12 is
It can be adjusted automatically and accurately. This allows
A humidification amount control device 60 is provided as compared with a conventional device in which a humidification amount control device provided with a pump is provided outside the fuel cell 10.
The structure of will be simplified at once. Moreover, the humidification amount control device 6
0 is incorporated in the fuel cell 10, the fuel cell 1
As a result, it is possible to easily downsize the entire equipment in which 0 is incorporated and to reduce the manufacturing cost.

As the amount of humidification of the electrolyte membrane 12 decreases, the volume of the whole electrolyte membrane 12 decreases. Therefore, each water permeable conduit 26 is released from the pressed state by the protrusion 54, a flow of humidifying water from the water supply passage 52 to the water discharge passage 62 is generated, and the humidification to the electrolyte membrane 12 is restarted. .

Further, in the first embodiment, the water introducing means 5
The needle member 58 constituting 6 has a hollow shape, and the tip inserted into the electrolyte membrane 12 is made porous. Therefore, there is an advantage that the humidifying water can be smoothly and surely supplied from the water supply passage 52 to each of the water permeable pipes 26.

Humidification amount control device 10 according to the second embodiment
0 is shown in FIG. This humidification amount control device 100
Is the water-permeable conduit 10 provided inside the electrolyte membrane 12.
2, the water permeable conduit 102 has a plurality of passage portions 102a and 102b extending in the horizontal direction and the vertical direction inside the electrolyte membrane 12.

A water supply passage 104 is formed at one end on the lower side of the first manifold plate 46, and a horizontal opening end of the water supply passage 104 facing the electrolyte membrane 12 side is formed at the electrolyte membrane 12 side.
It corresponds to the lower end of the water permeable conduit 102 provided inside. A needle member 106 that constitutes water introducing means is inserted into the horizontal opening end of the water supply passage 104, and the needle member 1
The tip of 06 is inserted into the electrolyte membrane 12 and faces the water-permeable conduit 102. A protrusion 108 as an actuating portion is formed so as to bulge at a position located on the side of the needle member 106 and corresponding to the water-permeable conduit 102.

A water drainage channel 110 is similarly formed on one end side of the upper portion of the first manifold plate 46, and an end portion of the water drainage channel 110 opening to the electrolyte membrane 12 side is a water permeable conduit line 102. The needle member 112 is inserted into this open end.

In the humidifying amount control device 100 according to the second embodiment having such a configuration, the single needle member 106 constituting the water introducing means is inserted into the electrolyte membrane 12 so that the needle member 106 is removed. Humidification water is supplied from the water supply passage 104 to the water permeable conduit 102 inside the electrolyte membrane 12 via the water supply passage 104. And this humidifying water is a water-permeable conduit 1
The electrolyte membrane 12 is humidified through the plurality of passages 102a and 102b forming 02, and the surplus portion is discharged from the water discharge passage 110 to the outside.

When the electrolyte membrane 12 is sufficiently humidified and swells, the protrusion 1 provided near the water supply passage 104.
The water permeable conduit 102 is closed at a portion corresponding to 08. As a result, the amount of humidifying water supplied to the inside of the electrolyte membrane 12 is automatically controlled.

Therefore, in the second embodiment, the humidifying water can be supplied to the inside of the electrolyte membrane 12 from the single water supply passage 104, and the single projecting portion 1 serves as the operating portion.
It is only necessary to include 08, and it is possible to obtain the effect of further simplifying the structure of the entire humidification amount control device 100.

FIG. 7 shows a humidification amount control device 120 according to the third embodiment. This humidification amount control device 12
0 is a water permeable conduit 1 provided inside the electrolyte membrane 12.
22 and the water permeable conduit 122 includes the first
Of the humidification amount control device 60 according to the embodiment
6, or the humidification amount control device 10 according to the second embodiment
No. 0 water-permeable conduit 102.

The first manifold plate 46 is provided with a pipe line 124 that constitutes a water supply line, and a needle member 126 is inserted in communication with the end of the pipe line 124. The first gasket 30 interposed between the first manifold plate 46 and the electrolyte membrane 12 is formed with an opening 128 for communicating the conduit 124 side with the electrolyte membrane 12 side.

In the humidifying amount control device 120 according to the third embodiment configured as described above, the needle member 1 is connected to the needle member 1 through the conduit 124.
Humidification water is supplied to the water-permeable conduit 122 of the electrolyte membrane 12 via 26, and the electrolyte membrane 12 is humidified.
On the other hand, when the electrolyte membrane 12 is sufficiently humidified and swells, the electrolyte membrane 12 swells from the opening 128 of the first gasket 30 toward the conduit 124, and the conduit 124 is closed (indicated by 2 in FIG. 7). (See dotted line). This allows the pipeline 124
The effect of limiting the supply of humidifying water from the water to the water permeable conduit 122 and easily and automatically adjusting the amount of humidification of the electrolyte membrane 12 is obtained.

In the first to third embodiments, the humidification amount control devices 60, 100 and 120 are arranged on the first manifold plate 40 side, but instead of this, the humidification amount control devices 60, 100 and 120 are arranged on the second manifold plate 66 side. It may be provided.

[0044]

EFFECT OF THE INVENTION In the humidification amount control device for a solid polymer electrolyte membrane according to the present invention, the solid polymer electrolyte is directly introduced into the water passage formed inside the solid polymer electrolyte membrane. When the solid polymer electrolyte membrane is sufficiently humidified and swells while the membrane is humidified, the supply amount of the humidifying water is adjusted via the operating portion provided in the separator. Thus, it is not necessary to provide a humidification amount control device outside the fuel cell, and the humidification amount of the solid polymer electrolyte membrane can be automatically and accurately adjusted with a simple and inexpensive structure.

[Brief description of the drawings]

FIG. 1 is a schematic perspective explanatory view of a fuel cell in which a humidification amount control device according to a first embodiment of the present invention is incorporated.

FIG. 2 is a partially exploded perspective view of the fuel cell.

FIG. 3 is a vertical cross-sectional view of the fuel cell.

FIG. 4 is an exploded perspective view of the humidification amount control device.

FIG. 5 is an operation explanatory view of the humidification amount control device.

FIG. 6 is a perspective explanatory view of a humidification amount control device according to a second embodiment.

FIG. 7 is a vertical cross-sectional explanatory view of a humidification amount control device according to a third embodiment.

[Explanation of symbols]

10 ... Fuel cell 12 ... Electrolyte membrane 14 ... Air electrode 16 ... Hydrogen electrode 18 ... Fuel cell structure 20 ... Separator 26 ... Water permeable conduits 40, 42 ... Separator part 46 ... Manifold plate 52 ... Water supply path 54 ... Projection Part 56 ... Water introducing means 58, 106, 126 ... Needle member 60, 100, 12
0 ... Humidity control device

Claims (5)

[Claims] 1. A fuel cell in which a fuel cell structure constituted by sandwiching a solid polymer electrolyte membrane between a cathode side electrode and an anode side electrode and separators sandwiching the fuel cell structure are alternately laminated, A water passage provided inside the solid polymer electrolyte membrane for allowing the humidifying water to flow therethrough and diffusing the humidifying water into the solid polymer electrolyte membrane, and the water from the water supply passage formed in the separator. Water introducing means for introducing the humidifying water into the passage, provided in the separator, the solid polymer electrolyte membrane is humidified and swelling to swell the water passage or the water supply passage, an actuating portion capable of closing. A humidification amount control device for a solid polymer electrolyte membrane, comprising: 2. The humidification amount control device according to claim 1, wherein
The humidification amount control device for a solid polymer electrolyte membrane, wherein the water passage is formed of a water permeable conduit embedded inside the solid polymer electrolyte membrane. 3. The humidification amount control device according to claim 1,
The water introduction means includes a hollow needle member having a porous tip inserted into the water passage from the water supply passage, and a humidification amount control device for a solid polymer electrolyte membrane. 4. The humidification amount control device according to claim 1,
The operating unit includes a protrusion provided on the inside of the solid polymer electrolyte membrane and protruding toward the water passage side. 5. The humidification amount control device according to claim 1,
The said operation part is provided with the opening part which connects the said water supply path side to the said solid polymer electrolyte membrane side, The humidification amount control apparatus of the solid polymer electrolyte membrane characterized by the above-mentioned.