JP5309852B2 - Humidifier and fuel cell device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire conductivity between power-generating parts without using external wiring while preventing corrosion, when a pair of power-generating parts are so laminated as to sandwich a hollow fiber membrane module. <P>SOLUTION: The humidifier includes the hollow fiber membrane module and a box housing the hollow fiber membrane module, and the box is sandwiched between the pair of power-generating parts, and box and the pair of power-generating parts are so arranged as to be laminated. The box of the humidifier has insulation, and a through hole along the lamination direction is formed around the region where the hollow fiber membrane module is housed. The through hole is provided with a conductive member conducting the pair of power-generating parts. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a humidifier and a fuel cell device.

Conventionally, in a fuel cell device, it is necessary to operate by humidifying a reaction gas in order to keep the ion exchange membrane moist. For this reason, a humidifier is mounted on the fuel cell device. A humidifier equipped with a hollow fiber membrane module and a metal casing for housing the hollow fiber membrane module is known (see, for example, Patent Document 1). Patent Document 1 describes a humidifier in which an insulating resin film is disposed between a humidifier and a current collector plate in order to prevent energization of a metal casing.
JP 2008-10205 A

  Incidentally, in a flat plate type fuel cell device in which a plurality of power generation units are stacked, temperature variations in the stacking direction are likely to occur. In order to maintain high power generation efficiency, it is desirable to suppress temperature variations. Therefore, it has been studied to suppress temperature variation by interposing heat between the humidifier and the power generation unit with one or more humidifiers interposed between the power generation units.

  However, when the humidifier described in the above-mentioned document is arranged between the power generation units, a current flows through the casing because the casing is made of metal. If this happens, the metal material may corrode in a predetermined temperature / humidity environment for humidification applications such as fuel cells.

  In order to prevent this corrosion, it is conceivable to place an insulating film between the hollow fiber membrane module and the power generation unit, but when an insulating film is interposed between the humidifier and the power generation unit as described above. The electrical conductivity between the hollow fiber membrane module and the power generation unit is cut off. For this reason, it is necessary to use an external wiring to electrically connect a pair of adjacent power generation units via the hollow fiber membrane module. Use of external wiring not only increases the size of the apparatus but also increases the labor of wiring work.

  The subject of this invention is ensuring the electroconductivity between power generation parts, without using external wiring, preventing a corrosion, when a pair of power generation part is laminated | stacked so that a hollow fiber membrane module may be pinched | interposed.

According to one aspect of the invention,
Humidification provided with a hollow fiber membrane module and a housing that houses the hollow fiber membrane module, the housing being sandwiched between a pair of power generation units, and the housing and the pair of power generation units being stacked A vessel,
The casing has an insulating property, and a through hole is formed along the stacking direction in the periphery outside the area where the hollow fiber membrane module is stored .
A humidifier is provided in which the through hole is provided with a conductive member for conducting the pair of power generation units.

In the humidifier, preferably, the housing includes
An opening penetrating in the stacking direction in a region in which the hollow fiber membrane module is stored ;
An insulating and elastic film is provided so as to cover both ends of the opening in the stacking direction.
Preferably, in the humidifier described above, a plurality of the through holes are provided so as to surround a region where the hollow fiber membrane module is accommodated,
The conductive member is provided in each of the plurality of through holes.
Preferably, in the humidifier, a fastening hole into which a fastening jig for fastening the power generation unit and the housing is inserted in at least one of the intervals between the plurality of through holes is the stacked layer. It is formed along the direction.
In the humidifier, preferably, the conductive member protrudes from the through hole.
In the humidifier, preferably, the conductive member has elasticity.
In the humidifier described above, the housing is preferably made of resin .
In the humidifier, preferably, the film is made of a resin.
In the humidifier described above, the thickness of the film is preferably in the range of 0.2 μm to 20 μm.

According to another aspect of the invention,
The above humidifier,
A fuel cell device is provided, comprising: a pair of power generation units that sandwich the casing of the humidifier.

  According to the present invention, since the casing has an insulating property and the conductive member is provided in the through hole along the stacking direction, when the pair of power generation units are stacked so as to sandwich the hollow fiber membrane module, The member conducts the pair of power generation units. Therefore, when a pair of power generation units are stacked on both ends, it is possible to provide a humidifier that can ensure electrical conductivity between the power generation units without using external wiring while preventing corrosion of the casing.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

  FIG. 1 is a block diagram of a power generation device 400 provided with the fuel cell device 1. The power generation device 400 is provided in a notebook personal computer, a mobile phone, a PDA (Personal Digital Assistant), an electronic notebook, a wristwatch, a digital still camera, a digital video camera, a game device, a game machine, and other electronic devices. Yes, it is used as a power source for operating the electronic device main body.

The power generation device 400 includes a fuel container 401, a fuel pump 402, a vaporizer 403, a reformer 404, a carbon monoxide remover 405, an air pump 406, and the fuel cell device 1.
The fuel container 401 stores fuel such as methanol and water separately or in a mixed state. The fuel pump 402 sucks fuel and water from the fuel container 401 and supplies them to the vaporizer 403. The vaporizer 403 vaporizes the fuel and water supplied from the fuel container 401 via the fuel pump 402 to generate an air-fuel mixture. The reformer 404 generates hydrogen gas, carbon dioxide gas and the like from the fuel / water mixture supplied from the vaporizer 403 as shown in the following chemical reaction formulas (1) and (2).

CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ (1)
2CH ₃ OH + H ₂ O → 5H ₂ + CO + CO ₂ (2)

  The carbon monoxide remover 405 removes carbon monoxide from the air-fuel mixture by oxidizing the carbon monoxide in the air-fuel mixture supplied from the reformer 404 as shown in the following chemical reaction formula (3), and the fuel. It produces gas.

2CO + O ₂ → 2CO ₂ (3)

  The air pump 406 sucks outside air and supplies the sucked air to the carbon monoxide remover 405 and the fuel cell device 1.

  The fuel cell device 1 generates electric energy by an electrochemical reaction between hydrogen gas in the fuel gas supplied from the carbon monoxide remover 405 and oxygen gas supplied from the air pump 406.

  FIG. 2 is a perspective view showing a schematic configuration of the fuel cell device. As shown in FIG. 2, the fuel cell device 1 includes a pair of power generation units 2 and a humidifier 3 sandwiched between the pair of power generation units 2.

Each of the pair of power generation units 2 is formed by stacking a plurality of single cells 21. The single cell 21 includes a membrane electrode assembly 22 and a pair of separators 23 that sandwich the membrane electrode assembly 22 in the thickness direction. Hydrogen gas and oxygen gas flow into the single cell 21 through the humidifier 3 and pass through the separator 23 and the membrane electrode assembly 22, thereby generating a power generation reaction. Each of the pair of power generation units 2 only needs to include at least one single cell 21.
And a pair of electric power generation part 2 and the humidifier 3 are fastened by the some screw | thread 25 which is a fastening jig concerning this invention.

  3 is a top view of the humidifier 3 as viewed from above, and FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. As shown in FIGS. 3 and 4, the humidifier 3 includes a hollow fiber membrane module 30 and a housing 40 that houses the hollow fiber membrane module 30.

The hollow fiber membrane module 30 includes a hollow fiber membrane 31 and hollow fiber supports 32 provided at both ends of the hollow fiber membrane 31.
The hollow fiber membrane 31 has a large number of hollow fibers having a cavity in the center, and is a membrane having water molecule permeability. When the hollow fiber membrane 31 is immersed in water, water molecules penetrate into the hollow fiber membrane 31 and the gas flowing through the hollow fiber membrane 31 is humidified.
As such a hollow fiber membrane 31, what consists of a polyimide, a fluorine-type polymer membrane, etc. can be used. A hollow fiber membrane made of polyethylene, PVDF (polyvinylidene fluoride), polyethersulfone, polyacrylonitrile, cellulose acetate, or the like may be used.

  The hollow fiber support 32 is formed by curing, for example, a heat-curing resin, a naturally-curing resin, a photo-curing resin, or the like, and fixes both ends of the hollow fiber membrane 31. In the fixed state, both ends of the hollow fiber membrane 31 are exposed, and a fluid can enter and exit the hollow fiber membrane 31 from the end.

  The casing 40 is made of an insulating resin such as polypropylene or polyethylene. The housing | casing 40 is clamped by a pair of electric power generation part 2, and the housing | casing 40 and a pair of electric power generation part 2 are laminated | stacked by this. The housing 40 is formed with an opening 41 penetrating in the stacking direction. The opening 41 is a region in which the hollow fiber membrane module 30 is accommodated.

A plurality of through holes 42 are formed around the opening 41 so as to surround the opening 41 along the stacking direction. The through hole 42 is provided with a conductive member 43 that conducts the pair of power generation units 2. The conductive member 43 is a conductive elastomer having elasticity, for example. Specifically, the conductive elastomer is formed, for example, by highly dispersing carbon particles or metal particles in silicon rubber. As shown in FIG. 4, both end portions of the conductive member 43 protrude from the through hole 42, and the protruding portion of the conductive member 43 contracts when the casing 40 is sandwiched between the pair of power generation portions 2, thereby generating the power generation portion 2. Close contact with.
Further, as shown in FIG. 3, a fastening hole 44 into which the screw 25 is inserted is formed between each of the plurality of through holes 42 so as to follow the stacking direction.

  As shown in FIGS. 3 and 4, when the hollow fiber membrane module 30 is housed in the opening 41, the hollow fiber support 32 is in close contact with the inner peripheral surface of the opening 41, and the hollow fiber in the opening 41 is The outer regions 45 and 46 and the inner region 47 are closed from the support 32. As a result, the outer regions 45 and 46 and the inner region 47 do not communicate with each other. Moreover, since the both ends of the hollow fiber membrane 31 of the hollow fiber membrane module 30 are exposed from the hollow fiber support body 32, the hollow fiber membrane 31 and the outer regions 45 and 46 communicate with each other. The inner region 47 of the opening 41 penetrates along the stacking direction, but the outer regions 45 and 46 have shielding walls 45a and 46a formed at the upper and lower ends, respectively, and do not penetrate.

  A gas inlet 48 into which the fuel gas supplied from the carbon monoxide remover 405 or the oxygen gas supplied from the air pump 406 flows in the vicinity of one outer region 45 of the pair of outer regions 45 and 46. Is formed. The gas inlet 48 communicates with one outer region 45, and the gas flowing in from the gas inlet 48 is supplied into the hollow fiber membrane 31 through the one outer region 45.

  A gas outlet 49 communicating with the outer region 46 is formed in the vicinity of the other outer region 46 of the pair of outer regions 45 and 46. The gas outlet 49 communicates with the pair of power generation units 2. The gas that has passed through the hollow fiber membrane 31 flows out from the gas outlet 49 through the other outer region 46 and is supplied to the pair of power generation units 2.

  In the vicinity of the inner region 47, a water inlet 50 through which water flows into the inner region 47 and a water outlet 51 through which water in the inner region 47 is discharged are formed. The water inlet 50 and the water outlet 51 are respectively arranged at positions that are point-symmetric with respect to the approximate center of the inner region 47. When the hollow fiber membrane 31 allows fluids having different partial pressures of water to flow inside and outside, the water molecules that are liquid move from one to the other. When the inner region 47 is filled with water, water molecules that are liquid outside the hollow fiber membrane 31 penetrate into the hollow fiber membrane 31 and the gas flowing through the hollow fiber membrane 31 is humidified. become. For this reason, it is desirable that the hollow fiber membrane 31 is always immersed in sufficient water, and it is preferable that more water than the amount used for humidification is supplied from the water inlet 50.

At the upper and lower ends of the opening 41, a pair of reinforcing members 55 are disposed so as to be stretched along a direction orthogonal to the direction in which the hollow fiber membrane 31 extends from one outer region 45 to the other outer region 46. ing.
In addition, films 60 are provided on the upper and lower ends of the housing 40 so as to cover both ends of the inner region 47. The film 60 is an insulating and elastic film. Specifically, the film 60 may be a resin thin film such as insulating silicon rubber or polyolefin.

Next, the operation of this embodiment will be described.
When the humidifier 3 is not sandwiched between the pair of power generation units 2, when water flows in from the water inlet 50 until the inside region 47 is filled as shown in FIG. 5, the membrane 60 is elastically deformed by the water pressure. Will swell outward. Here, when the humidifier 3 does not include the elastic film 61 and the casing 40 does not have elasticity, the outer wall of the casing 40 is maintained in a flat state without swelling (see FIG. 5 Refer to the dotted line).

  Here, when the humidifier 3 is sandwiched between the pair of power generation units 2, a gap S between the humidifier 3 and the power generation unit 2 as shown in FIG. 6 due to distortion of the separator 23 caused by assembly or processing. May occur. If the humidifier 3 does not include the elastic membrane 61 and the housing 40 does not have elasticity, the membrane 61 remains flat even if the inner region 47 is filled with water. The gap S remains as it is.

The humidifier 3 is suitable for driving a fuel cell that has a dew point near the driving temperature of the fuel cell device 1 by heating the gas with heat generated by the power generation unit 2 generating electricity in addition to humidifying the gas. It also has the function of supplying wet gas. However, if the gap S remains, heat conduction from the power generation unit 2 to the humidifier 3 is suppressed.
However, if the film 60 has elasticity, the film 60 swells, so that the film 60 adheres to the surface of the separator 23 as shown in FIG. 7, and the gap S is eliminated, so that the amount of heat conduction can be increased. Become.

  In general, the thermal conductivity of the resin is about 0.1 to 0.6 W / m · K. This is significantly smaller than the thermal conductivity of metals such as SUS316 = 16 W / m · K and aluminum = 180 W / m · K. When the amount of heat conducted through the flat plate is q, the thermal conductivity of the material is λ, the thickness is L, and the temperature difference between both sides of the plate is Δθ, these relationships are expressed by the following formula (4).

  q = λ · Δθ / L (4)

  If Δθ is constant from equation (4), the thermal conductivity of SUS316 having a thickness of about 500 μm is q = 0.032Δθ. The thickness of the resin having a thermal conductivity equivalent to this is about 3.1 μm to 19 μm. Similarly, the thickness of the resin having a thermal conductivity equivalent to that of aluminum having a thickness of about 500 μm is about 0.28 μm to 1.7 μm. That is, as described above, the film 60 is a resin thin film, but it is desirable that the thickness be in the range of 0.2 μm to 20 μm in order to have a thermal conductivity equivalent to that of SUS316 or aluminum.

  When the humidifier 3 is sandwiched between the pair of power generation units 2, the protruding portion of the conductive member 43 is pushed and the conductive member 43 is compressed. Thereby, since a pair of electric power generation part 2 and the electrically-conductive member 43 contact | adhere, a pair of electric power generation part 2 will conduct | electrically_connect through the electrically-conductive member 43. FIG.

  As described above, according to the present embodiment, the housing 40 has insulating properties, and the conductive member 43 is provided in the through hole 42 along the stacking direction, so that the hollow fiber membrane module 30 is sandwiched between them. When the pair of power generation units 2 are stacked on each other, the conductive member 43 makes the pair of power generation units 2 conductive. Therefore, when a pair of power generation units are stacked on both ends, it is possible to ensure conductivity between the power generation units 2 without using external wiring while preventing corrosion of the housing 40.

In addition, since the conductive member 43 is provided in each of the plurality of through holes 42, the resistance can be reduced as compared with the case where the number of the conductive members 43 is one, and the loss can be reduced.
In addition, since the fastening hole 44 into which the screw 25 is inserted is formed in at least one of the intervals between the plurality of through holes 42, the interval between the through holes 42 can be effectively utilized, It is possible to reduce the size.

  Since the conductive member 43 protrudes from the through hole 42, when the humidifier 3 is sandwiched between the pair of power generation units 2, the conductive member 43 is pushed and contracts. Since the conductive member 43 attempts to return to elasticity, the adhesion with the separator 23 is enhanced.

  Since the housing | casing 40 and the film | membrane 60 are formed from resin, it can prevent that housing | casing 40 itself corrodes.

  Note that the present invention is not limited to the above embodiment, and can be modified as appropriate. In the following description, the same parts as those in the above embodiment are denoted by the same reference numerals and the description thereof is omitted.

  For example, in the above-described embodiment, the case where the conductive member 43 itself is formed of a material having elasticity is illustrated, but the conductive member 43a may be elastic depending on the shape as shown in FIG. The conductive member 43a shown in FIG. 8 is made of metal, and both end portions 431 are curved inward. In addition, storage recesses 421 are formed at both ends of the through-hole 42a to store part of the both ends 431 of the conductive member 43a so as to protrude outward. When the humidifier 3A provided with the conductive member 43a is sandwiched between the pair of power generation units 2, both end portions 431 of the conductive member 43a are pushed and elastically deformed in the storage recess 421 to be in close contact with the separator 23. . Accordingly, it is possible to increase the electrical conductivity as compared with the conductive member 43 made of a conductive elastomer while improving the adhesion between the conductive member 43a and the separator 23.

It is a block diagram of the electric power generating apparatus provided with the fuel cell apparatus of this embodiment. It is a perspective view which shows schematic structure of the fuel cell apparatus of this embodiment. It is the top view which looked at the humidifier with which the fuel cell apparatus of FIG. 2 is equipped from the top. It is IV-IV sectional drawing of FIG. It is sectional drawing which shows the state with which the humidifier of FIG. 4 was filled with water. It is sectional drawing which shows the relationship between the humidifier provided with the film | membrane which does not have elasticity, and the separator of a pair of electric power generation part. It is sectional drawing which shows the relationship between the humidifier of FIG. 4 and the separator of a pair of electric power generation part. It is sectional drawing which shows the 1st modification of the humidifier of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell apparatus 2 Electric power generation part 3 Humidifier 21 Single cell 22 Membrane electrode assembly 23 Separator 25 Screw (fastening jig)
DESCRIPTION OF SYMBOLS 30 Hollow fiber membrane module 31 Hollow fiber membrane 32 Hollow fiber support body 40 Case 41 Opening part 42 Through-hole 43 Conductive member 44 Fastening hole 45 Outer region 46 Outer region 47 Inner region 48 Gas inlet 49 Gas outlet 50 Water inlet 51 Water outlet 55 Reinforcement material 60 Membrane

Claims (10)

Humidification provided with a hollow fiber membrane module and a housing that houses the hollow fiber membrane module, the housing being sandwiched between a pair of power generation units, and the housing and the pair of power generation units being stacked A vessel,
The casing has an insulating property, and a through hole is formed along the stacking direction in the periphery outside the area where the hollow fiber membrane module is stored .
The humidifier, wherein the through hole is provided with a conductive member for conducting the pair of power generation units. The humidifier according to claim 1,
In the case,
An opening penetrating in the stacking direction in a region in which the hollow fiber membrane module is stored ;
A humidifier comprising an insulating and elastic film so as to cover both ends of the opening in the stacking direction. The humidifier according to claim 1 or 2,
A plurality of the through holes are provided so as to surround the periphery of the region in which the hollow fiber membrane module is stored ,
The humidifier, wherein the conductive member is provided in each of the plurality of through holes. The humidifier according to claim 3,
A fastening hole into which a fastening jig for fastening the power generation unit and the housing is inserted is formed along at least one of the intervals between the plurality of through holes along the stacking direction. A humidifier characterized by In the humidifier as described in any one of Claims 1-4,
The humidifier according to claim 1, wherein the conductive member protrudes from the through hole. The humidifier according to claim 5, wherein
The humidifier, wherein the conductive member has elasticity. In the humidifier as described in any one of Claims 1-6,
The humidifier is characterized in that the casing is made of resin. The humidifier according to claim 2, wherein
  The humidifier, wherein the film is made of resin. The humidifier according to claim 8,
  A humidifier, wherein the thickness of the film is within a range of 0.2 μm to 20 μm. The humidifier according to any one of claims 1 to 9,
  A fuel cell device comprising: a pair of power generation units that sandwich the housing of the humidifier.

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