JPH11151416A - Solid high molecular electrolytic type humidity exchanging module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to operate while interrupting the flying of dust or the like floating in the air and constantly keeping an electrolytic reaction surface in a cleaned state. SOLUTION: A single cell 30 constituting a solid high molecule electrolytic type humidity exchanging module 50 is constituted so that a pair of selective steam permeation membranes 52a, 52b are mounted to close opening parts of both surface of a frame member 55 and a solid high molecular electrolytic element 51, which is formed by press fitting porous electrodes 53a and 53b to both surface of a solid high molecular electrolyte membrane 19 through a platinum based catalytic layer by heating, is mounted so that a closed space constituted of the frame member 55 and a pair of the selective steam permeation membranes 52a and 52b is divided into a 1st closed space 54a and a 2nd closed space 54b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a humidity exchange module which incorporates a solid polymer electrolyte element for performing moisture exchange by electrolyzing water vapor using a hydrogen ion conductive solid polymer electrolyte membrane, and in particular, relates to an electrolytic solution. The present invention relates to a module structure for preventing dust and sticky chemical substances, which are factors that degrade reaction characteristics, from adhering to an electrolytic reaction surface.

[0002]

2. Description of the Related Art FIG. 10 is a cross-sectional view showing a dehumidifying device described in, for example, Japanese Patent Application Laid-Open No. 4-41616. This dehumidifying device is a solid polymer electrolytic device having a function of electrolyzing water vapor in the air. It dehumidifies the space using electrochemical functions. In FIG. 10, a dehumidifier 1 has a solid polymer electrolytic element 2 having a function of electrolyzing water vapor in the air, and a solid polymer electrolytic element 1 for electrolyzing water vapor.
, And is fitted into an opening 6 provided in a part of the wall surface of the housing 5. Then, the inside of the housing 5 is isolated from the outside by the dehumidifying device 1 to form a closed space. As shown in FIG. 11, the solid polymer
a and 8b are formed into a composite membrane by thermocompression bonding on both surfaces of a solid polymer electrolyte membrane 7 for selectively passing hydrogen ions (protons) via platinum-based catalyst layers 9 for promoting an electrolytic reaction. . Here, as the solid polymer electrolyte membrane 7, for example, a Nafion (registered trademark of Du Pont) membrane or the like is used. For the electrodes 8a and 8b, for example, expanded titanium plated with platinum or the like is used. In addition, non-woven fabric of carbon fiber or the like can be used for the electrode on the cathode side.

Next, the operation of the conventional dehumidifier will be described. The DC power supply 3 is connected to the solid polymer electrolyte element 2 fitted into the opening 6 of the housing 5 such that the dehumidified side (inside of the housing 5) is an anode and the humidified side (atmosphere side) is a cathode. Have been. Therefore, when power is supplied from the DC power supply 3 between the electrode 8a (anode) and the electrode 8b (cathode), water vapor in the air on the anode side is electrolyzed, and water molecules are formed by the reaction of the formula (1). Decomposes to generate oxygen and reduce humidity. _{Anode: 2H 2 O → O 2 +} 4H + + 4e - ··· (1) Further, entrained in the hydrogen ions move to the cathode side from the anode side through the solid polymer electrolyte membrane 7, 1-3 A plurality of water molecules move from the anode side to the cathode side. Therefore, since water molecules are consumed on the anode side, the humidity is reduced and dry air is obtained. Further, hydrogen ions (H ⁺ ) generated on the anode side during the electrolytic reaction pass through the solid polymer electrolyte membrane 7 and reach the cathode. On the other hand, the electrons (e ⁻ ) reach the cathode through an external circuit. Then, water is generated by consuming oxygen on the cathode side by the reaction of the formula (2). Cathode side: O ₂ + 4H ⁺ + 4e ⁻ → H ₂ O (2) Thereby, the air on the cathode side is humidified and becomes humid air.
The power required for the electrolytic reaction represented by the above equations (1) and (2) is supplied from the DC power supply 3. In addition, a platinum-based catalyst layer 9 is formed at the joint interface between the solid polymer electrolyte membrane 7 and the electrodes 8a and 8b, and promotes the electrolytic reactions of the formulas (1) and (2).

Therefore, the water vapor in the closed space in the housing 5 is
By opening the opening / closing shutter 4 and supplying power from the DC power supply 3 to the solid polymer electrolyte element 2,
The humidity is controlled inside. When the power supply by the DC power supply 3 is stopped, the open / close shutter 4 is closed,
The humidity flowing from the outside into the housing 5 is blocked, and the humidity in the housing 5 is kept constant.

[0005]

As described above, in the conventional dehumidifier, since the electrolytic reaction surface of the solid polymer electrolyte element 2 is in direct contact with the atmosphere, dust, oil, and tar floating in the atmosphere are removed. Such an adhesive component adheres to the electrolytic reaction surface of the solid polymer electrolyte element 2, causing a problem that contact between the gas and the catalyst layer 9 deteriorates and deteriorates the electrolytic characteristics.
In particular, when the cathode surface of the polymer electrolyte element 2 is contaminated and oxygen is not sufficiently supplied to the electrolysis reaction surface, hydrogen ions release electrons to emit flammable hydrogen gas, which is diffused. Therefore, it is necessary to always keep the electrolytic reaction surface in a clean state in order to cause a risk of causing a problem such as ignition.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has been made by covering an electrolysis reaction surface of a solid polymer electrolytic element with a selective water vapor permeable membrane that selectively allows only water vapor to pass therethrough. Prevents airborne dust, oil, and sticky chemicals such as tar from coming to the electrolytic reaction surface, and keeps the electrolytic reaction surface clean at all times to reduce dust and sticky chemicals. It is an object of the present invention to obtain a solid polymer electrolyte type humidity exchange module that can prevent a decrease in electrolytic characteristics due to adhesion and further prevent the release of flammable hydrogen gas.

[0007]

In the solid polymer electrolyte type humidity exchange module according to the present invention, a pair of selective water vapor permeable membranes for selectively transmitting only water vapor are provided on both opposite sides of the frame member. A solid polymer formed by attaching a porous electrode to both surfaces of a proton conductive solid polymer electrolyte membrane through a platinum-based catalyst layer, with the porous electrodes attached to the frame member so as to close the openings. An electrolytic element includes a closed space formed by the frame member and the pair of selective water vapor permeable membranes, a first closed space on one selective water vapor permeable membrane side and a second closed space on the other selective water vapor permeable membrane side. A single cell attached to the frame member so as to define a closed space, and a DC power supply for supplying a DC voltage between the porous electrodes of the solid polymer electrolyte element of the single cell. is there.

In addition, a plurality of the unit cells are stacked via a spacer so as to form an air passage between the adjacent unit cells, and the stacked unit cells face each other. The electrodes are electrically connected in series so that the polarities of the electrodes are the same.

[0009] Further, the air flow flowing through the adjacent air passages is configured to form a cross flow with each other.

An oxygen air supply path for supplying oxygen in the anode-side closed space of the first and second closed spaces to the cathode-side closed space of the first and second closed spaces; And an exhaust path for exhausting unreacted gas in the closed space on the cathode side of the first and second closed spaces to the outside.

Further, the oxygen gas supply passage is provided with a passage of water vapor provided through the solid polymer electrolyte element so as to communicate between the first closed space and the second closed space. The communication hole has a small diameter that can be ignored.

In addition, a noble metal catalyst layer is interposed in the exhaust path.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a sectional view showing a solid polymer electrolyte humidity exchange module according to Embodiment 1 of the present invention. In FIG. 1, a single cell 30 constituting a solid polymer electrolyte type humidity exchange module 50 includes a solid polymer electrolyte element 5
1 is disposed inside the frame member 55 with its outer peripheral portion supported by a cylindrical frame member 55, and a pair of selective water vapor permeable membranes 52.
a and 52b are arranged so as to close the openings provided on both opposing surfaces of the frame member 55, respectively. A frame member 55 and a pair of selective water vapor permeable membranes 52a, 52a,
2b is a closed space composed of the solid polymer electrolyte element 5
1 defines first and second closed spaces 54a and 54b. Then, the first closed space 54a side is the anode surface,
The DC power supply 3 is connected to the solid polymer electrolyte element 51 such that the second closed space 54b side is the cathode surface. Also,
The frame member 55 has ventilation holes 56a, 56b, 56c. Then, the first and second closed spaces 54a,
4b is a ventilation port 56a, a ventilation path 57a and a ventilation port 56b.
Are communicated through. Further, the second closed space 54b
Is communicated to the outside through a ventilation port 56c and a ventilation path 57b. And, in the path of this ventilation path 57b,
A noble metal catalyst layer 59 is provided.

Here, the solid polymer electrolyte type humidity exchange module 50 is constituted by the single cell 30 and the DC power supply 3, and the oxygen supply passage is constituted by the vents 56a and 56b and the passage 57a. And an air passage 57b constitute an exhaust passage. In addition, the solid polymer electrolyte element 51 has platinum catalyst layers on both surfaces of a hydrogen ion conductive solid polymer electrolyte membrane 49 for selectively passing hydrogen ions (protons) through the pair of porous electrodes 53a and 53b. It is formed into a composite film by thermocompression bonding. The solid polymer electrolyte membrane 49 is, for example, a Nafion (registered trademark of DuPont) membrane. Also, the porous electrode 53
For example, expanded titanium or the like plated with platinum is used for a and 53b. Note that a nonwoven fabric of carbon fiber may be used for the porous electrode on the cathode side. Further, the selective water vapor permeable membranes 52a and 52b are films having a function of selectively transmitting only water vapor and not transmitting other gas components or liquid substances, and are described in, for example, JP-A-1-194927. Film is used.

Next, the characteristics of the selective water vapor permeable membrane will be described. As the selective water vapor permeable membrane, a polytetrafluoroethylene membrane stretched to have a porous thickness of 4
A sulfonic acid group-containing fluorine-based copolymer having a thickness of 10 μm on a porous membrane having a thickness of 0 μm, a porosity of 75%, and a maximum pore size of 0.5 μm.
A film obtained by performing a drying treatment at 100 ° C. for 180 minutes after air-drying was used. This selective water vapor permeable membrane has gas permeation characteristics shown in FIG. Further, this selective water vapor permeable membrane is provided with an opening of 50 cm ² in a part of a 15 liter capacity housing, and this selective water vapor permeable membrane is attached so as to close the opening, and the housing is placed at a relative humidity. FIG. 3 shows the result of measuring the change in humidity inside the housing when placed in a 25% environment. From FIG. 3, it can be seen that the humidity inside the housing decreases over time so as to approach the humidity outside the housing. That is, when the outer surface is in a low humidity state of 25% humidity, the water vapor in the housing passes through the selective water vapor permeable membrane and is discharged to the outside, and the humidity in the housing is reduced to the same humidity as the outside air. Is shown. This shows that the humidity in the closed space can be adjusted by forming a humidity difference between the selective water vapor permeable films. FIG. 4 shows the result of measuring the amount of air passing through the permeable membrane by applying a pressure difference between the surfaces of the selective water vapor permeable membrane. From FIG. 4, it can be seen that air does not permeate when the pressure difference between the surfaces is 30 cm · Hg or less. From these facts, it can be seen that this selective water vapor permeable membrane has the property of selectively transmitting only water vapor within a certain pressure range if there is a difference in humidity between the surfaces.

Next, the operation of the solid polymer electrolyte type humidity exchange module 50 according to the first embodiment will be described. The DC power supply 3 is connected to the solid polymer electrolytic element 51 such that the porous electrode 53a serves as an anode and the porous electrode 53b serves as a cathode. Therefore, when power is supplied between the pair of porous electrodes 53a and 53b from the DC power supply 3, the first
The water vapor in the air on the closed space 54a side is electrolyzed and water molecules are decomposed by the reaction of the formula (1), generating oxygen and reducing the humidity. _{Anode: 2H 2 O → O 2 +} 4H + + 4e - ··· (1) further moves in the first closed space 54b side through the solid polymer electrolyte membrane 49 from the first closed space 54a side Along with the hydrogen ions, one to three molecules of water molecules move from the first closed space 54a to the second closed space 54b. Therefore, the air on the first closed space 54a side is dehumidified because water molecules are consumed. Further, hydrogen ions (H ⁺ ) generated on the anode side during the electrolytic reaction pass through the solid polymer electrolyte membrane 49 and reach the porous electrode 53b (cathode). On the other hand, the electron (e
^- ) Reaches the porous electrode 53b through an external circuit. Then, water is generated by consuming oxygen on the cathode side by the reaction of the formula (2). Cathode side: O ₂ + 4H ⁺ + 4e ⁻ → H ₂ O (2) Therefore, the air in the second closed space 54b is humidified and becomes highly saturated air.

As described above, since the air in the first closed space 54a is dehumidified, a humidity difference is formed between the selective water vapor permeable films 52a, and the vapor of the outside air is indicated by an arrow A in FIG. The water is transmitted through the selective water vapor permeable membrane 52a so as to be supplied to the first closed space 54a. On the other hand, the second closed space 54b
Since the air inside is humidified, the selective water vapor permeable membrane 52b
, A moisture difference is formed between the films, and the water vapor in the second closed space 54b passes through the selective water vapor permeable film 52b as shown by an arrow B in FIG. In the course of the electrolytic reaction, hydrogen ions move through the solid polymer electrolyte element 51 and react with oxygen on the cathode surface to generate water vapor. It becomes gas and accumulates on the top of the second closed space 54b. The second closed space 54b is in an oxygen gas atmosphere, and when hydrogen gas is accumulated, it reacts with oxygen to be in a dangerous state, and is released to the outside through the ventilation path 57b. At this time,
Since the noble metal catalyst layer 59 is provided in the path of the ventilation path 57b, the hydrogen gas is consumed by reacting with an equivalent amount of oxygen by the catalytic action of the white metal element constituting the noble metal catalyst layer 59, and is safe. Released outside. Therefore, if the solid polymer electrolytic humidity exchange module 50 is used in place of the dehumidifier 1 shown in FIG. 10, the humidity inside the housing 5 can be controlled. Further, since the anode-side electrolysis reaction surface is isolated from the outside air by the selective water vapor permeable membrane 52a, the anode-side electrolysis reaction surface can be operated without contacting the atmosphere.

Here, regarding the material balance at both electrodes of the solid polymer electrolyte element 51, oxygen is generated at the anode and the same amount of oxygen is consumed at the cathode. In the single cell 30, since the first and second closed spaces 54a and 54b are communicated with each other through the ventilation port 56a, the ventilation path 57a and the ventilation port 56b, the oxygen generated at the anode is reduced to the first closed space. Air is supplied from the space 54a to the second closed space 54b, and is supplied to the cathode for consumption. Therefore, the balance of oxygen is balanced, and it becomes unnecessary to supply oxygen from outside air. That is, it is possible to operate the cathode-side electrolysis reaction surface without bringing it into contact with the atmosphere. In the case where water vapor generated on the cathode side is condensed, a drain vent may be provided at the cathode side space, that is, at the bottom of the second closed space 54b to drain the condensed water.

As described above, according to the first embodiment,
Since the anode-side electrolysis reaction surface and the cathode-side electrolysis reaction surface of the solid polymer electrolysis device 51 can be operated without directly contacting the outside air, there is a danger of poisoning dust in the outside air and a catalyst substance forming a catalyst layer. Can be prevented from adhering to the electrolytic reaction surface of a gas component such as an organic acid having the above, and the electrolytic reaction surface can be always maintained in a clean state. Therefore, the gas in the first and second closed spaces 54a and 54b and the catalyst layer are always in good contact with each other, and a decrease in the electrolytic characteristics is suppressed. Further, oxygen is sufficiently supplied to the cathode-side electrolysis reaction surface, so that it is possible to prevent hydrogen ions from emitting electrons and being released as flammable hydrogen gas.

FIG. 5 shows the voltage-current characteristics of the solid polymer electrolytic humidity exchange module 50. For comparison, a curve X shows a voltage-current characteristic of the solid polymer electrolyte type humidity exchange module from which the selective water vapor permeable membranes 52a and 52b are removed. From FIG. 5, in the module in which the electrolytic reaction surface of the polymer electrolyte element 51 is in contact with the atmosphere (curve X),
The current increases as the voltage rises, and the current reaches equilibrium at 2.5 V or more, and the equilibrium current value is 1.9 A. on the other hand,
In the module of the present invention in which the electrolytic reaction surface of the polymer electrolyte element 51 does not come into contact with the atmosphere (curve Y), the current increases as the voltage increases, and the current reaches equilibrium at 2.5 V or more, and the equilibrium current value is 1 3A. This means that the module having the electrolytic reaction surface not in contact with the atmosphere (the present invention) has an equilibrium current value of 7 compared to the module in which the electrolytic reaction surface is in contact with the atmosphere.
Although it is reduced to about 0%, it means that the water vapor can be moved without bringing the electrolytic reaction surface into contact with the atmosphere, and the operation can be performed without being contaminated by dust or the like.

Embodiment 2 FIG. 6 is a perspective view showing a solid polymer electrolyte type humidity exchange module according to Embodiment 2 of the present invention, FIG. 7 is a sectional view taken along the line VII-VII of FIG. 6, and FIG.
FIG. 2 is a sectional view showing a single cell which is a component of the solid polymer electrolyte type humidity exchange module. In each figure, the solid polymer electrolyte element 51 is formed into a substantially square
5 is formed in a frame shape. The solid polymer electrolyte element 51 is mounted on the frame member 55 with its outer periphery supported by the frame member 55 over the entire circumference. Furthermore, a pair of selective water vapor permeable membranes 52 formed in a substantially square shape
a and 52b are attached so as to close the openings provided on both opposing surfaces of the frame member 55, respectively, to form the unit cell 31. That is, in the single cell 31, the solid polymer electrolyte element 51 defines a closed space formed by the frame member 55 and the pair of selective water vapor permeable membranes 52a, 52b in the first and second closed spaces 54a, 54b. It is arranged so that it may be. Also, in a part of the frame member 55,
An air passage 57a that connects the first and second closed spaces 54a and 54b is formed, and a still another portion is formed with an air passage 57b that communicates the second closed space 54b with the outside. In addition, this ventilation path 57b is open on both opposite sides of the frame member 55. Single cell 3 configured in this manner
1 has basically the same structure as the single cell 30 according to the first embodiment, and has the same function.

In the solid polymer electrolyte type humidity exchange module 60 according to the second embodiment, the plurality of single cells 31 configured as described above are maintained at a constant interval via a spacer 62 formed in a rectangular parallelepiped. And the first closed space 54a
The layers or the second closed spaces 54b are stacked so as to face each other, and are integrally formed by being pressed from both ends in the stacking direction. The space between the single cells 31 formed at a fixed interval by the spacer 62 constitutes air passages 63a and 63b as air passages. Further, the spacers 62 are alternately arranged at both ends of the single cell 31 so that the air flows flowing in the adjacent air flow paths 63a and 63b form a cross flow. Further, through holes 64 are formed in the spacer 62 in the laminating direction, and the air passages 57 b of each single cell 31 communicate with each other via the through holes 64. The second closed space 54b of each unit cell 31 is communicated with the outside through the ventilation path 57b and the through hole 64, and further through the noble metal catalyst layer 59. Each single cell 31 is electrically connected in series so that the same electrode of the porous electrode 53a (anode) and the same electrode of the porous electrode 53b (cathode) face each other,
The DC power supply 3 is connected to the upper and lower unit cells 31 in the stacking direction, so that power required for the electrolytic reaction is supplied to all the unit cells 31. The electrical connection between the single cells 31 is made, for example, by using the porous electrodes 53a and 53b of the single cell 31.
Exposing the contact piece electrically connected to the frame member 55,
This can be achieved by shorting the contacts in series.
Here, a large number of unit cells 31 and spacers 52 are stacked.
And the DC power supply 3, the solid polymer electrolyte type humidity exchange module 60 is constituted, the oxygen passage is constituted by the ventilation passage 57a, and the exhaust passage is constituted by the ventilation passage 57b and the through hole 64.

Next, the operation of the solid polymer electrolyte type humidity exchange module 60 will be described. Air flows along arrows C and D through air passages 63a and 63b formed by stacking the unit cells 31 at a certain interval by the spacer 62. Then, when power is supplied from the DC power supply 3 to the stacked body of the unit cells 31, the water vapor in the air on the first closed space 54a side of each unit cell 31 is electrolyzed to generate oxygen and generate humidity. Decrease. Further, hydrogen ions (H ⁺ ) generated on the anode side during the electrolytic reaction pass through the solid polymer electrolyte membrane 49 and reach the porous electrode 53b (cathode). On the other hand, the electrons (e ⁻ ) reach the porous electrode 53b through an external circuit.
Then, on the cathode side, water is generated by consuming oxygen, and the air in the second closed space 54b is humidified to become highly saturated air.

As described above, since the air in the first closed space 54a of each unit cell 31 is dehumidified, a humidity difference is formed between the surfaces of the selective water vapor permeable membrane 52a, and the air flows through the air passage 63b. As shown by arrow A, the water vapor of the generated air passes through the selective water vapor permeable membrane 52a and is supplied to the first closed space 54a to replenish the water vapor consumed in the electrolytic reaction. On the other hand, since the air in the second closed space 54b of each single cell 31 is humidified, a humidity difference is formed between the surfaces of the selective water vapor permeable membrane 52b, and the water vapor in the second closed space 54b is displaced by an arrow B. As shown in the figure, the air passes through the selective water vapor permeable membrane 52b and is discharged to the air passage 63a, and the air flowing through the air passage 63a is humidified. In the course of the electrolytic reaction, hydrogen ions move through the solid polymer electrolyte element 51 and react with oxygen on the cathode surface to generate water vapor. It becomes gas and accumulates in the second closed space 54b. The second closed space 54b is in an oxygen gas atmosphere, and when hydrogen gas is accumulated, it reacts with oxygen to be in a dangerous state, and is released to the outside through the ventilation path 57b and the through hole 64. At this time, the hydrogen gas reacts with an equivalent amount of oxygen by the catalytic action of the white metal element constituting the noble metal catalyst layer 59, is consumed, and is released to the outside in a safe form. The oxygen generated at the anode is sent from the first closed space 54a to the second closed space 54b via the ventilation path 57a as shown by an arrow E, and oxygen consumed at the cathode is replenished. You.

As described above, in the second embodiment, each single cell 31 is composed of the solid polymer electrolyte element 51 and the air passage 63 formed by the selective water vapor permeable membranes 52 a and 52 b and the frame member 55.
Since it is shut off from the air passing through a and 63b, the electrolysis reaction surface of the solid polymer electrolytic element 51 is made of an organic acid or the like which has a risk of poisoning dust in the air or a catalyst substance forming a catalyst layer. It does not come into direct contact with gas components and is always kept in a clean state. Further, oxygen generated at the anode is sent from the first closed space 54a to the second closed space 54b through the ventilation path 57a and is supplied to the cathode for consumption. The balance of oxygen at both electrodes is balanced. Further, the unreacted gas (hydrogen gas) accumulated in the second closed space 54b is released to the outside through the ventilation path 57b and the through-hole 64 and further through the noble metal catalyst layer 59, so that The reaction gas is consumed by reacting with an equivalent amount of oxygen by the catalytic action of the white metal element constituting the noble metal catalyst layer 59, and is discharged to the outside in a safe form. Therefore, also in the second embodiment, the first embodiment
The same effect can be obtained.

Further, according to the second embodiment, since a large number of single cells 31 are stacked, a large humidity exchange capacity can be obtained, and the present invention is also applicable to applications requiring a large humidity exchange capacity. can do. In addition, since the air flow paths 63a and 63b are formed so that the air flows form a cross flow with each other, the supply and discharge of air to and from the stacked body of the single cells 31 are facilitated.

Embodiment 3 In the first embodiment, the ventilation holes 56a and 56b are formed in the frame member 55, and the ventilation holes 56a and 56b are connected by the ventilation path 57a to communicate the first and second closed spaces 54a and 54b. In the second embodiment, the ventilation path 57a is directly formed in the frame member 55 to communicate the first and second closed spaces 54a and 54b, and the oxygen is transferred from the first closed space to the second closed space. However, in the third embodiment, as shown in FIG. 9, the passage of water vapor through some of the electrodes and the electrolytic membrane on the electrolytic reaction surface of the solid polymer electrolyte element 51 can be neglected. A communication hole 65 having such a small diameter is formed, and the first and second closed spaces 54a and 54b are communicated with each other to supply oxygen from the first closed space to the second closed space. The effect of is obtained. Further, there is no need to form the ventilation holes 56a, 56b and the ventilation path 57a in the frame member 55, which facilitates the production of the single cell. The oxygen air supply path is not limited to the communication hole 65 that communicates the first and second closed spaces 54a and 54b,
It suffices if the passage of water vapor is restricted.

[0028]

According to the present invention, a pair of selective water vapor permeable membranes for selectively transmitting only water vapor are formed on the frame member so as to close the openings respectively provided on both opposing surfaces of the frame member. The solid polymer electrolyte element is formed by attaching the porous electrodes to both surfaces of the hydrogen ion conductive solid polymer electrolyte membrane via a platinum-based catalyst layer by hot pressing. The frame member defines a closed space formed by the water vapor permeable membrane into a first closed space on one selective water vapor permeable membrane side and a second closed space on the other selective water vapor permeable membrane side. A single cell attached to the
Since a DC power supply for supplying a DC voltage between the porous electrodes of the solid polymer electrolyte device of the single cell is provided, the anode-side electrolysis reaction surface and the cathode-side electrolysis reaction surface of the solid polymer electrolysis device are directly exposed to the outside air. It can be operated without touching, and it is possible to prevent gas components such as organic acids, which have a risk of poisoning the dust in the outside air and the catalyst substance forming the catalyst layer, from adhering to the electrolytic reaction surface, It can always be kept clean. Therefore, the gas in the first and second closed spaces and the catalyst layer are always in good contact with each other, the deterioration of the electrolysis characteristics is suppressed, oxygen is sufficiently supplied to the cathode-side electrolysis reaction surface, and hydrogen ions are generated. A solid polymer electrolyte type humidity exchange module is thus obtained in which the emission of electrons to flammable hydrogen gas is prevented.

A plurality of the unit cells are stacked via a spacer so as to form an air passage between adjacent unit cells, and the stacked unit cells face each other. Since the electrodes are electrically connected in series so as to have the same polarity, the humidity exchange capacity can be increased.

Further, since the air flows flowing through the adjacent ventilation paths form a cross flow with each other,
The supply and exhaust of air becomes easy.

An oxygen air supply path for supplying oxygen in the closed space on the anode side of the first and second closed spaces to the closed space on the cathode side of the first and second closed spaces; An exhaust path for exhausting unreacted gas in the closed space on the cathode side of the first and second closed spaces is provided, so that the balance of oxygen on both electrode surfaces of the single cell is balanced, and oxygen from outside air is balanced. Supply is not required.

Further, the oxygen air supply passage is provided with a passage of water vapor provided through the solid polymer electrolyte element so as to communicate between the first closed space and the second closed space. Since the communication hole has a small diameter that can be ignored, it is easy to manufacture the frame member.

Further, since the noble metal catalyst layer is interposed in the path of the exhaust path, hydrogen gas which is an unreacted gas can be released to the outside in a safe form.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a solid polymer electrolyte humidity exchange module according to Embodiment 1 of the present invention.

FIG. 2 is a view showing a transmission speed ratio between various gas components and water vapor of a selective water vapor permeable membrane used in a solid polymer electrolyte type humidity exchange module of the present invention.

FIG. 3 is a diagram showing a water vapor transmission characteristic of a selective water vapor permeable membrane used in the solid polymer electrolyte type humidity exchange module of the present invention.

FIG. 4 is a diagram showing gas permeation characteristics of a selective water vapor permeable membrane used in the solid polymer electrolyte type humidity exchange module of the present invention.

FIG. 5 is a current-voltage characteristic diagram of the solid polymer electrolyte humidity exchange module according to Embodiment 1 of the present invention.

FIG. 6 is a cross-sectional view showing a solid polymer electrolyte type humidity exchange module according to Embodiment 2 of the present invention.

7 is a sectional view taken along the line VII-VII in FIG.

FIG. 8 is a cross-sectional view showing a single cell applied to a solid polymer electrolyte humidity exchange module according to Embodiment 2 of the present invention.

FIG. 9 is a cross-sectional view showing a solid polymer electrolyte type humidity exchange module according to Embodiment 3 of the present invention.

FIG. 10 is a cross-sectional view illustrating a conventional dehumidifier using a solid polymer electrolyte element.

FIG. 11 is a schematic configuration diagram of a conventional solid polymer electrolyte device.

[Explanation of symbols]

3 DC power supply, 30, 31 single cell, 49 solid polymer electrolyte membrane, 50, 60 solid polymer electrolyte type humidity exchange module, 51 solid polymer electrolyte element, 52a, 52b selective water vapor permeable membrane, 53a, 53b porous Electrode, 54
a first closed space, 54b second closed space, 55 frame members, 56a, 56b vents (oxygen air supply path), 56c
Vent (exhaust passage), 57a Vent (oxygen supply passage), 5
7b ventilation path (exhaust path), 59 noble metal catalyst layer, 62 spacer, 63a, 63b air flow path (air ventilation path),
64 through holes (exhaust passages), 65 communication holes (oxygen supply passages).

Claims (6)

[Claims] 1. A porous electrode, wherein a pair of selective water vapor permeable membranes for selectively transmitting only water vapor are attached to a frame member so as to respectively close openings provided on both opposing surfaces of the frame member. A solid polymer electrolyte element formed by hot-pressing each side of a proton conductive solid polymer electrolyte membrane via a platinum-based catalyst layer is composed of the frame member and the pair of selective water vapor permeable membranes. A single unit attached to the frame member so as to define a closed space to be defined as a first closed space on one selective water vapor permeable membrane side and a second closed space on the other selective water vapor permeable membrane side. A solid polymer electrolyte type humidity exchange module, comprising: a cell; and a DC power supply for supplying a DC voltage between the porous electrodes of the solid polymer electrolyte element of the single cell. 2. A plurality of the unit cells are stacked via a spacer so as to form an air passage between adjacent unit cells, and the stacked unit cells face each other. 2. The solid polymer electrolyte type humidity exchange module according to claim 1, wherein the electrodes are electrically connected in series so that the electrodes have the same polarity. 3. The solid polymer electrolyte humidity exchange module according to claim 2, wherein the air flows flowing through the adjacent ventilation paths form a cross flow with each other. 4. An oxygen air supply path for supplying oxygen in an anode-side closed space of the first and second closed spaces to a cathode-side closed space of the first and second closed spaces, First and second
4. A solid polymer electrolytic humidity exchange according to claim 1, further comprising an exhaust path for exhausting unreacted gas in the closed space on the cathode side of the closed space to the outside. module. 5. The oxygen gas supply path is provided for passing water vapor provided through the solid polymer electrolyte element so as to communicate between the first closed space and the second closed space. 5. The solid polymer electrolyte humidity exchange module according to claim 4, wherein the communication hole has a small diameter that can be ignored. 6. The solid polymer electrolyte humidity exchange module according to claim 4, wherein a noble metal catalyst layer is interposed in the exhaust path.