JP4951385B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system, and more particularly to a technique for operating a fuel cell efficiently.

  Among the fuel cells, a direct methanol type fuel cell is particularly regarded as a power source for a small device. A direct methanol fuel cell uses an aqueous methanol solution as a fuel and oxygen in the air as an oxidant. Compared to the fact that many other types of fuel cells use hydrogen and require a reformer, direct methanol fuel cells have the advantage of not requiring a reformer. Further, since methanol is a liquid at room temperature, it can be easily attached to the fuel cell by being packed in a cartridge or the like, and has a high energy density. Accordingly, direct methanol fuel cells are considered promising as power sources for mobile devices.

  A direct methanol fuel cell generates electricity by the following reaction. A direct methanol fuel cell is disposed between a fuel electrode to which a methanol aqueous solution as a fuel is supplied, an air electrode to which air containing oxygen as an oxidizing agent for methanol is supplied, and the fuel electrode and the air electrode. And a polymer electrolyte membrane.

In the fuel electrode supplied with the aqueous methanol solution, carbon dioxide (CO ₂ ), protons (H ⁺ ), and electrons (e ⁻ ) are generated by the reaction of methanol and water represented by the following chemical formula (1). Protons generated at the fuel electrode go to the air electrode through the polymer electrolyte membrane. On the other hand, electrons flow to an external circuit connected to the fuel electrode. Electrons that have finished their work in the external circuit go to the air electrode. Carbon dioxide is discharged outside the system.

CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ (1)
At the air electrode, as shown in the following chemical formula (2), oxygen (O ₂ ) obtained from air, protons (H ⁺ ) coming from the fuel electrode, and electrons (e) coming from the fuel electrode through an external circuit (e ^- ) Reacts with it to produce water (H ₂ O).

(3/2) O ₂ + 6H ⁺ + 6e ⁻ → 3H ₂ O (2)
Therefore, in a direct methanol fuel cell, it is necessary to sufficiently supply air to the air electrode. Conventional air supply control techniques at the air electrode include a technique that uses natural air convection and a method that uses a small fan or pump attached to the air supply port side or exhaust port side of the fuel cell. (See Patent Document 1).

  Further, as can be seen from the chemical formula (2), moisture is generated in the air electrode by the reaction. When the produced water adheres to the air electrode, there is a problem that the amount of air supplied to the reaction decreases, and as a result, the output efficiency of the fuel cell decreases. The decrease in the amount of product water adhering to the air electrode is called flooding. On the other hand, as can be seen from the chemical formula (1), water is consumed at the fuel electrode. Therefore, it is considered to reuse the generated water by efficiently collecting the generated water at the air electrode and supplying it to the fuel electrode.

Until now, as a technique for recovering and reusing generated water at the air electrode, a method of recovering the generated water and supplying it to the fuel electrode with a pump (see Patent Document 2) and a capillary phenomenon caused by a cloth or a porous body have been used. There was a method (refer patent document 3) to do.
Japanese Patent Laying-Open No. 2004-342511 (FIG. 6, paragraph 0020) JP 2003-368866 A (FIG. 1, paragraph 0050) JP 2004-241363 A (FIG. 1, paragraphs 0068-0070)

  The technique disclosed in Patent Document 1 relates to a technique for supplying air to the air electrode, and the techniques disclosed in Patent Document 2 and Patent Document 3 efficiently recover the generated water at the air electrode. Is. Each of these techniques represents one means for solving a known problem, but there still seems to be room for improvement in terms of efficiency in the entire apparatus.

  In the technology that uses natural convection of air to supply air to the air electrode, there is a problem that the amount of power generation is limited by the amount of air supplied. If a fan and a pump are used for air supply and product water recovery, a part of the electric power is consumed and the power generation efficiency is lowered. Further, in the technology for recovering the generated water using the capillary phenomenon, the penetration of fuel into the air electrode side becomes a problem, which also causes a decrease in power generation efficiency.

  Therefore, an object of the present invention is to provide a fuel cell system capable of stably supplying air containing oxygen necessary for power generation to an air electrode.

  Another object of the present invention is to provide a fuel cell system that can stably and sufficiently supply air containing oxygen necessary for power generation and efficiently recover generated water at the air electrode. It is.

  Another object of the present invention is to efficiently supply a sufficient amount of air to the air electrode and recover the generated water in the air electrode, and to penetrate the fuel from the fuel electrode to the air electrode. It is an object of the present invention to provide a fuel cell system that can prevent the above-described problem.

  Still another object of the present invention is to efficiently realize the function of forcibly supplying air to the air electrode and the function of recovering the generated water in the air electrode, and to penetrate the fuel from the fuel electrode to the air electrode. It is to provide a fuel cell system that can be prevented.

  Another object of the present invention is to realize a function of forcibly supplying air to the air electrode and a function of collecting generated water at the air electrode using a single power source, and a fuel from the fuel electrode to the air electrode. It is an object of the present invention to provide a fuel cell system that can prevent the penetration of water.

  A fuel cell system using a predetermined liquid fuel as a fuel according to the present invention includes a fuel cell structure having a first surface and a second surface. Water is generated on the first surface of the fuel cell structure along with power generation by the fuel cell, and a predetermined liquid fuel is supplied to the second surface. The fuel cell system further includes a plate member having a main surface disposed at a predetermined distance from the first surface so as to be parallel to the first surface, and the main surface of the plate member is porous. Made of material. The fuel cell system further includes a rotation driving means for rotating the plate-like member in a predetermined direction around an axis that intersects the first surface at a right angle.

  As the fuel cell generates power, water is generated on the first surface. When the water droplet formed by this water has a certain size or more, it touches the main surface of the plate-like member arranged at a predetermined distance from the first surface. Since the main surface of the plate-like member is formed of a porous material, this water is absorbed by the plate-like member. The plate-like member is rotationally driven by the rotation driving means, and the water absorbed by the plate-like member moves outward in the plate-like member by centrifugal force and is discharged from the peripheral edge of the plate-like member. Since the water inside the plate member is quickly discharged, the water does not stay inside the plate member. Therefore, the water formed on the first surface is quickly absorbed by the plate-like member, and the water generated on the first surface does not stay on the first surface. As a result, air containing oxygen necessary for power generation of the fuel cell structure can be supplied to the first surface without being obstructed by the water retained on the first surface. That is, by setting the first surface as the surface on the air electrode side of the fuel cell structure, it is possible to provide a fuel cell system capable of stably supplying air to the air electrode.

  Preferably, the plate member is a disk member.

  By using the plate-like member as a disk-like member, the space around the plate-like member can be used without waste.

  More preferably, the plate-like member includes a substrate having a main surface and made of a material that does not transmit moisture, and a porous layer formed on the main surface of the substrate. The surface of the porous layer forms the main surface of the plate member.

  Since the main surface of the plate-like member is a porous layer, water generated on the first surface can be absorbed. A substrate that does not transmit moisture is disposed on the other surface of the porous layer. Therefore, there is no possibility that the water absorbed by the plate member leaks out from the other surface of the plate member.

  More preferably, the plate-like member has a back surface parallel to the main surface, and the plate-like member has a first opening penetrating from the back surface to the main surface, and the shape of the first opening portion Is selected so that the air on the back side is forcibly moved to the main surface side when the plate-like member is rotated about the axis by the rotation driving means.

  When the plate-like member is rotated about the axis by the rotation driving means, the air on the back surface side of the plate-like member moves to the main surface side through the first opening. That is, air containing oxygen necessary for power generation is forcibly supplied to the first surface, and a sufficient amount of air can be supplied to the air electrode.

  The plate-like member may further have a second opening penetrating from the main surface to the back surface.

  The air forcibly supplied to the first surface through the first opening is naturally discharged from the space near the first surface through the second opening.

  The shape of the second opening may be selected so that the air on the main surface side is forcibly moved to the back surface side when the plate-like member is rotated about the axis by the rotation driving means. .

  When the plate-like member is rotated about the axis by the rotation driving means, the air on the main surface side of the plate-like member moves to the back side through the second opening. That is, the air in the vicinity of the first surface is forcibly discharged, air can be smoothly supplied to the first surface through the first opening, and a sufficient amount of air can be supplied to the air electrode. become.

  The shape of the second opening is selected such that the distance between the center and the center on the back surface side of the second opening is larger than the distance between the center and the center on the main surface side. Also good.

  By forming the second opening in such a shape, the air discharged from the main surface side to the back surface side gathers near the rotation center on the back surface side. By guiding this air to the outside, the air used for the operation of the fuel cell system can be quickly discharged to the outside.

  Preferably, the first opening is formed such that a position of the first opening closest to the center of rotation of the plate-like member by the rotation driving unit is a predetermined distance from the center of rotation. The second opening is formed such that the position of the second opening farthest from the center of rotation is smaller than a predetermined distance.

  The position where the first opening is formed and the position where the second opening is formed are at different distances from the center of rotation. The air supplied from the first opening toward the first surface can be prevented from being immediately discharged from the second opening, and the first surface contains oxygen necessary for power generation. A sufficient amount of air can be stably supplied.

  The fuel cell system further includes a wall member attached at a predetermined distance from the center of the back surface of the plate member so as to surround the center of rotation of the plate member, and faces the back surface by the wall member. The space may be divided into two.

  The air supplied to the fuel cell through the first opening and the air discharged through the second opening are not mixed in the vicinity of the back surface, efficiently supplying air to the fuel cell, And used air can be discharged quickly.

  More preferably, the plate-like member has a back surface parallel to the main surface, and the plate-like member has a first opening penetrating from the main surface to the back surface. The shape of the first opening is selected so that the air on the main surface side is forcibly moved to the back surface side when the plate-like member is rotated about the axis by the rotation driving means.

  The plate-like member may further have a second opening penetrating from the back surface to the main surface.

  The shape of the second opening is selected so that the distance between the center of the second opening on the main surface side and the center is larger than the distance between the center on the back side and the center. Also good.

  The second opening is formed such that the position of the first opening closest to the center of rotation of the plate-like member by the rotation driving means is a predetermined distance from the center of rotation. The opening of the first opening is formed so that the position farthest from the center of rotation of the first opening is smaller than a predetermined distance.

  The fuel cell system further includes a wall member attached to the back surface at a predetermined distance so as to surround the center of rotation of the plate-like member, and the space facing the back surface is divided into two by the wall member. Also good.

  The air supplied to the fuel cell through the first opening and the air discharged through the second opening are not mixed in the vicinity of the back surface, efficiently supplying air to the fuel cell, And used air can be discharged quickly.

  A notch of a predetermined size may be formed around the plate member.

  Through this notch, air is efficiently supplied to the air electrode of the fuel cell.

  More preferably, the first opening is formed in a shape such that the opening on the main surface side and the opening on the back surface side do not overlap when viewed from a direction perpendicular to the main surface.

  When the fuel cell system is arranged at a position where water droplets are dropped from the first surface onto the plate member, the dropped water droplets pass through the first opening and leak to the back surface side of the plate member. Can be prevented.

  More preferably, the second opening is also formed in a shape such that the opening on the main surface side and the opening on the back surface side do not overlap when viewed from a direction perpendicular to the main surface.

  When the fuel cell system is arranged at a position where water droplets are dropped from the first surface onto the plate member, the dropped water droplets pass through the second opening and leak to the back surface side of the plate member. Can be prevented.

  The plate-like member includes a substrate having a main surface made of a material that does not transmit moisture, and a hydrophilic layer formed on the main surface of the substrate, and the surface of the hydrophilic layer covers the main surface of the plate-like member. You may come to form.

  The fuel cell system may further include a water repellent layer formed on the main surface of the substrate within a predetermined distance from the peripheral edge.

  Preferably, the plate member is a disk member. The fuel cell system further includes a cylindrical first porous body disposed around the plate-like member at a predetermined distance from the periphery of the plate-like member.

  The water discharged by the centrifugal force from the peripheral edge of the plate member is absorbed by the first porous body. Therefore, the risk that this water leaks to the outside can be reduced.

  More preferably, the cylindrical first porous body has a first end on the first surface side and a second end on the second surface side, and the first porous body has the first porous body. From the inner periphery of the second end portion of the material body, an overhang portion is formed that protrudes to a position closer to the center of rotation than the periphery of the plate-like member.

  Since water discharged from the peripheral edge of the plate-like member by centrifugal force is normally scattered outward from the peripheral edge, the water is absorbed by the portion of the first porous body arranged around the plate-like member. However, depending on the attitude of the fuel cell system, water may not reach those parts. Even in such a case, there is a high possibility that such water is absorbed by the overhang formed on the inner periphery of the second end of the first porous body, and the risk of water leaking to the outside can be further reduced.

  Preferably, the fuel cell system is further formed to be continuous with the first end portion of the first porous body, covers the second surface of the fuel cell structure, and contacts the second surface. A second porous body arranged in such a manner.

  The moisture absorbed by the plate member from the first surface is efficiently transported to the periphery of the plate member by centrifugal force and absorbed by the first porous body. The water absorbed by the first porous body is transferred from the first porous body to the second porous body formed so as to be continuous with the first porous body, and further to the second porous body. The inside is conveyed by capillary action and supplied to the second surface of the fuel cell structure. That is, the water generated on the first surface can be recovered and reused for power generation at the fuel electrode. Moreover, the 1st surface and the 1st porous body or the 2nd porous body are separated. Therefore, there is no possibility that the fuel will penetrate the first surface from the second surface through the first and second porous bodies. Further, the power necessary for this is only rotational drive means for rotating the plate-like member. That is, it is possible to efficiently supply a sufficient amount of air to the air electrode and to recover the generated water in the air electrode, and to prevent fuel from penetrating from the fuel electrode to the air electrode. It is possible to provide a fuel cell system that can be realized by using one power source.

  The fuel cell system further includes means for supplying a predetermined liquid fuel to the second porous body.

  Preferably, the first surface of the fuel cell structure is water repellent.

  Since the first surface is water-repellent, the generated water on the first surface forms water droplets and is quickly absorbed by the plate-like member from the first surface. The generated water spreads on the first surface and is less likely to cause so-called flooding, and power generation efficiency can be maintained high.

  According to the present invention, the water generated on the first surface accompanying the power generation of the fuel cell is absorbed by the plate-like member. Since the plate-like member is rotationally driven by the rotation drive means, the water absorbed by the plate-like member moves outward inside the plate-like member by centrifugal force and is quickly discharged from the periphery of the plate-like member. . The water generated on the first surface does not stay on the first surface.

  When the plate-like member is rotated about the axis by the rotation driving means, the air on the back surface side of the plate-like member moves to the main surface side through the first opening. That is, air containing oxygen necessary for power generation is forcibly supplied to the first surface, and a sufficient amount of air can be supplied to the air electrode. Further, the air on the main surface side of the plate-like member moves to the back surface side through the second opening. That is, the air in the vicinity of the first surface is forcibly discharged, air can be smoothly supplied to the first surface through the first opening, and a sufficient amount of air can be supplied to the air electrode. become.

  The water discharged by the centrifugal force from the peripheral edge of the plate member is absorbed by the first porous body. The water absorbed by the first porous body is transported by capillary action and supplied to the second surface of the fuel cell structure. That is, the water generated on the first surface can be recovered and reused for power generation at the fuel electrode. Moreover, the 1st surface and the 1st porous body or the 2nd porous body are separated. Therefore, there is no possibility that the fuel will penetrate the first surface from the second surface through the first and second porous bodies. Further, the power necessary for this is only rotational drive means for rotating the plate-like member. That is, it is possible to efficiently supply a sufficient amount of air to the air electrode and to recover the generated water in the air electrode, and to prevent fuel from penetrating from the fuel electrode to the air electrode. It is possible to provide a fuel cell system that can be realized by using one power source.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the figure, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[First Embodiment]
<Configuration>
The configuration of the system including the fuel cell system according to the first embodiment will be described below in detail with reference to FIGS. FIG. 1 shows an overall configuration of the system 20 in a block diagram form. Referring to FIG. 1, this system 20 includes a direct methanol fuel cell system 30 according to the present embodiment, a load 34 that is operated by power generated by the fuel cell system 30, and power generation by the fuel cell system 30. Power storage device 32 for storing the power to be supplied and supplying the power to load 34. Part of the electric power stored in the electricity storage device 32 is supplied to the fuel cell system 30 and used for forcibly supplying air to the fuel cell system 30.

  The fuel cell system 30 includes a fuel tank unit 40 that stores methanol as a fuel, and a fuel cell 42 that generates electric power using a reaction between fuel 54 supplied from the fuel tank unit 40 and oxygen in the air. . As will be described later, fuel cell 42 includes a fuel electrode that receives supply of fuel 54 from fuel tank unit 40 and an air electrode that receives supply of air 58 containing oxygen as an oxidant.

  The fuel cell system 30 further collects the generated water of the air electrode in the fuel cell 42 and receives a power supply from the power storage device 32 and a porous body 52 for supplying water as the water 56 to the fuel electrode using a capillary phenomenon. The function of supplying the air 58 to the air electrode of the fuel cell 42, the function of exhausting the air 60 from the air electrode of the fuel cell 42, and the generated water of the air electrode of the fuel cell 42 are efficiently porous. 52, the output voltage of the fuel cell 42 is monitored, and the rotation of the fan 50 is controlled so that the fuel cell system 30 operates with high efficiency. And a control unit 36.

  FIG. 2 shows the appearance of the fuel cell system 30. Referring to FIG. 2, the fuel cell system 30 has a substantially cylindrical shape as a whole, and includes a lower casing 72 constituting the lower part, an upper casing 70 constituting the upper part, an upper casing 70 and a lower part. It includes a seal member 74 for sealing a connection portion with the casing 72 and preventing fuel or moisture from leaking from the inside of the fuel cell system 30 to the outside.

  Around the lower housing 72, an air port 76 for intake and exhaust to the fuel cell 42 is formed. The air port 76 is vertically divided into an intake port 80 and an exhaust port 78 by a dividing member 82. A fuel tank unit mounting portion to which the fuel tank unit 40 is mounted is formed at the upper portion of the upper housing 70. By mounting the fuel tank unit 40 here, the fuel is supplied from the fuel tank unit 40 to the fuel electrode of the fuel cell 42.

  FIG. 3 is a plan view of the fuel cell system 30, and FIG. 4 is a cross-sectional view of the fuel cell system 30 taken along one-dot chain line 4-4 in FIG. 3.

  A detailed structure of the fuel cell system 30 will be described with reference to FIG. As described above, the fuel cell system 30 includes the upper housing 70 and the lower housing 72, and the seal member 74 disposed therebetween. A space in which the fuel tank unit 40 is mounted is formed in the upper part of the upper housing 70. The fuel tank unit 40 includes a housing 88 that holds the fuel 86 therein.

  Openings are formed in the center of the lower surface of the upper housing 70, the center of the upper surface of the lower housing 72, and the center of the seal member 74, and the fuel cell 42 is formed here. Details of the configuration of the fuel cell 42 will be described later.

  A fan 50 made of a porous rotating body is disposed immediately below the fuel cell 42. The fan 50 is disposed at a lower end of the shaft 94, a disk-shaped rotating plate 90 made of a porous material, a shaft 94 fixed at the center of the lower surface of the rotating plate 90 so as to rotate the rotating plate 90, and a lower housing. A motor 92 fixed on the bottom surface of the body 72 and a transmission 98 arranged in the middle of the shaft 94 are included. The rotating plate 90 is formed with an opening for forcibly supplying air to the lower surface of the fuel cell 42 as it rotates and forcibly exhausting air from the vicinity of the lower surface of the fuel cell 42. The configuration of these openings will be described later. The shaft 94 is fixed to the back surface of the rotating plate 90 so as to intersect with the surface of the rotating plate 90 at a right angle.

  The dividing member 82 extends from the outer periphery of the lower casing 72 to almost half the position from the center of the lower casing 72, and the space near the lower surface of the fuel cell 42 extends from the tip to the upper portion to the inner and outer portions. A partition plate 84 is attached. The lower portion of the lower housing 72 is divided by an internal partition wall 66, and an opening for passing the shaft 94 is formed at the center thereof. A bearing 96 is provided around the opening.

  FIG. 5 shows details of the configuration of the fuel cell 42. Referring to FIG. 5, fuel cell 42 has a water-repellent bottom surface, and the bottom surface is opposed to the top surface of rotating plate 90 with a predetermined distance and is opened to a nearby space. The air electrode 112 disposed on the lower surface of the air electrode 112, the polymer electrolyte layer 110 disposed on the air electrode 112, and the electrolyte layer 110. The fuel electrode 108 is disposed on the upper surface, and the fuel electrode 108 is supplied to the fuel 86 from the fuel tank unit 40, and the fuel electrode current collector 106 is disposed on a part of the fuel electrode 108. A structure composed of the air electrode current collector 114, the air electrode 112, the electrolyte layer 110, the fuel electrode 108, and the fuel electrode current collector 106 is hereinafter referred to as a “fuel cell structure”. A part of each of the air electrode current collector 114 and the fuel electrode current collector 106 is drawn outward, and is connected to the wiring to the power storage device 32 shown in FIG. The periphery of the electrolyte layer 110 is sealed with a seal member 74. The rotating plate 90 is disposed so that the surface thereof is parallel to the lower surface of the air electrode 112 and is spaced from the lower surface of the air electrode 112 by a predetermined distance.

  An overhang member 104 is provided on a portion of the lower housing 72 corresponding to the ceiling of the air inlet 80. On the overhang member 104, a peripheral wall portion 102 surrounding the periphery of the fuel cell structure from the outer peripheral portion of the rotating plate 90, and disposed near the upper surface of the fuel cell structure, covers the upper surface of the fuel cell structure, and A porous body 100 having an upper portion that is in contact with the upper surface (the fuel electrode 108) of the battery structure and further extends to the periphery thereof is disposed. 5 is a cross-sectional view in which the fuel electrode current collector 106 and the air electrode current collector 114 are formed up to the vicinity of the outer peripheral portion, the peripheral wall portion 102 of the porous body 100 is interrupted at this portion. In other parts, the peripheral wall 102 has a cylindrical shape surrounding the entire periphery of the fuel cell structure. The upper portion of the porous body 100 is continuous with the peripheral wall 102 at the end of the peripheral wall 102 on the cylindrical fuel tank unit 40 side. In addition, a portion of the porous body 100 that contacts the upper housing 70, the lower housing 72, and the seal member 74 and the outer periphery are water-repellent, and water inside the porous body 100 leaks to an unnecessary portion. It is not going out. The inner peripheral portion of the lower end of the cylindrical shape of the peripheral wall portion 102 of the porous body 100 slightly protrudes inward, and this protrusion extends further to the center side than the outer peripheral edge of the rotating plate 90 in this embodiment. By providing the overhang in this way, there is an effect that even when the attitude of the fuel cell system 30 is slightly changed, water scattered from the rotating plate 90 is reliably absorbed by the peripheral wall portion 102.

  In the present embodiment, the distance from the upper surface of rotating plate 90 to the lower surface of air electrode 112 is about 4 mm. The generated water on the surface of the air electrode 112 stays at the air electrode 112 up to about 3 mm, but it has been confirmed by experiments that it drops when it becomes larger than that. Therefore, in the case of a mobile device that may be used regardless of the top and bottom, it is desirable that the distance between the upper surface of the rotating plate 90 and the lower surface of the air electrode 112 be about 4 mm or less. However, in applications not intended for mobile use, it is considered that air can be supplied and water can be recovered even if this distance exceeds 4 mm.

  FIG. 6 shows a plan view of the rotating plate 90. 7 is a cross-sectional view taken along one-dot chain line 7-7 in FIG. 6, and FIG. 8 is a cross-sectional view taken along one-dot chain line 8-8 in FIG.

  Referring to FIGS. 6 and 7, air on the lower surface of the rotating plate 90 is supplied to the annular portion corresponding to the outer half of the rotating plate 90 at four positions shifted from each other by 90 degrees as the rotating plate 90 rotates. An upward opening 130 is formed on the upper surface of the rotating plate 90 so as to be forcibly moved. A rectifying plate 140 for smoothing the air flow is provided at a portion of the upward opening 130 on the upper surface side of the rotating plate 90 and upstream of the air flow 134.

  Similarly, referring to FIG. 6 and FIG. 8, the annular portion corresponding to the inner half of the rotating plate 90 has four positions shifted by 90 degrees from each other on the upper surface of the rotating plate 90 as the rotating plate 90 rotates. A downward opening 132 is formed that is selected to have a shape that forces air to move to the lower surface of the rotating plate 90. A rectifying plate 142 for smoothing the air flow is provided at a portion of the opening on the lower surface side of the rotating plate 90 in the downward opening 132 that is upstream of the air flow 136.

  Thus, in the present embodiment, the upward opening 130 is formed such that the distance to the position closest to the center of rotation of the rotating plate 90 is a predetermined distance larger than the radius of the rotating plate 90. The downward opening 132 is formed such that the distance from the center of rotation of the rotating plate 90 to the farthest position is smaller than the radius of the rotating plate 90. By doing so, the possibility that the air supplied to the air electrode 112 through the upward opening 130 is immediately discharged from the downward opening 132 is reduced, and a sufficient amount of air can be stably supplied to the air electrode 112. Can be done.

  In addition, a part of the generated water in the air electrode 112 is generated in the form of water vapor, and there is a possibility that dew condensation may occur on the parts existing around the air electrode 112 instead of the air electrode 112. In the present embodiment, since the component closest to the air electrode 112 is the rotating plate 90 and is close to the air electrode 112 over almost the entire lower surface of the air electrode 112, such moisture condensation is caused. If it occurs, it is most likely to occur on the rotating plate 90. In fact, it is considered that most of such condensation occurs on the rotating plate 90. As long as the water vapor condenses on the rotating plate 90 or inside the rotating plate 90, the water after the dew condensation is sent to the peripheral portion through the rotating plate 90 by centrifugal force, and the peripheral wall portion as well as the generated water on the air electrode 112. It moves on the porous body 100 from 102 and is collected on the fuel electrode side. Therefore, not only water generated on the air electrode 112 but also water generated near the air electrode 112 in the form of water vapor can be efficiently recovered.

<Operation>
1 to 9, the fuel cell system 30 according to the present embodiment operates as follows. Referring to FIG. 9, when the fuel tank unit 40 is attached to the upper housing 70, the fuel 86 in the fuel tank unit 40 further passes through the porous body 100 as indicated by an arrow 160, and the anode current collector 106. To reach. Since the lower surface of the air electrode 112 is open to the atmosphere, power is generated by the reaction at the fuel electrode 108 and the reaction at the air electrode 112 and is collected by the fuel electrode current collector 106 and the air electrode current collector 114. The stored power is output to the electricity storage device 32. This power is further applied to the load 34.

  On the other hand, when power is supplied from the power storage device 32 to the fan 50, the rotating plate 90 rotates in the direction indicated by the arrow 138 in FIG. By this rotation, outside air is forcibly introduced into the lower surface of the air electrode 112 as indicated by an arrow 162 in FIG. Further, as indicated by an arrow 164 in FIG. 9, the air near the lower surface of the air electrode 112 is forcibly discharged.

  Electric power is generated between the fuel electrode 108 and the air electrode 112 by the above-described reaction, and is output to the power storage device 32 shown in FIG. Along with this reaction, generated water is generated in the air electrode 112. The produced water is recovered on the fuel electrode 108 side as follows.

  The generated water in the air electrode 112 forms water droplets in the lower part of the air electrode 112. The water droplets adhere to the air electrode 112 to some extent (diameter of about 3 mm), but drop larger on the upper surface of the rotating plate 90. Since the rotating plate 90 is formed of a porous material, the water that has formed water droplets is absorbed by the rotating plate 90 as indicated by an arrow 172 in FIG. Furthermore, since the rotating plate 90 is rotating, this moisture moves to the periphery of the rotating plate 90 by centrifugal force.

  When the water reaches the periphery of the rotating plate 90, the water leaves the rotating plate 90 and tries to scatter as a water droplet around or around the outside. These water droplets hit the peripheral wall portion 102 of the porous body 100 and are absorbed by the porous body 100. The absorbed moisture moves inside the porous body 100 by capillarity as indicated by arrows 176 and 178, is mixed with the fuel 86 from the fuel tank unit 40, and is supplied to the fuel electrode 108. That is, the generated water in the air electrode 112 is efficiently collected by the centrifugal force due to the rotation of the rotating plate 90 and the capillary phenomenon by the porous body 100 and is collected on the fuel electrode 108 side.

  The basic idea in the present embodiment is that air is forcibly supplied to the lower surface of the air electrode 112, the air near the lower surface of the air electrode 112 is forcibly exhausted, and the lower surface of the air electrode 112 is Collecting the generated water efficiently in the porous body 100 is performed simultaneously with the rotation of the porous rotating plate 90. From the chemical formula, the amount of water produced, the amount of air consumed, and the amount of power generation are proportional. Since air is stably supplied to the air electrode 112 by the rotation of the rotating plate 90, there is little risk of shortage of air (oxygen) for power generation, and the amount of power generation is limited by the supply of air by natural convection. Absent. At the same time, air near the air electrode 112 is discharged to the outside, so that the air flow is smooth.

  In the configuration according to the present embodiment, air flows into the housing as indicated by an arrow 162 in FIG. 9, passes through the vicinity of the outer periphery of the rotating plate 90, and the upward opening 130 (see FIGS. 6 and 7). ), And passes through the space between the rotating plate 90 and the air electrode current collector 114 connected to the air electrode 112, and then passes through the vicinity of the inner periphery of the rotating plate 90 to the downward opening 132 (FIG. 6). And see FIG. 8) and is discharged as indicated by arrow 164. Therefore, when moisture exists in the porous body of the rotating plate 90 and the inflowing air is dry, the air humidified by the moisture contained in the rotating plate 90 is supplied to the space near the air electrode 112. It will be. That is, although it is slight, there is a possibility that the fuel cell system 30 according to the present embodiment can obtain a humidifying action on the air in the space near the air electrode 112.

  Further, the generated water in the air electrode 112 drops to the rotating plate 90 and is absorbed when it reaches a certain size. Moreover, the water | moisture content absorbed in the rotating plate 90 is rapidly conveyed outside with a centrifugal force. Accordingly, the generated water does not stay in the air electrode 112, and a decrease in power generation efficiency due to flooding can be prevented.

  Moisture absorbed by the rotating plate 90 and carried to the periphery by centrifugal force moves to the peripheral wall portion 102 of the porous body 100 and is collected on the fuel electrode 108 side by capillary action by the porous body 100.

  As described above, in the present embodiment, the supply of air to the air electrode 112, the exhaust of the air near the air electrode 112, the quick removal of the generated water in the air electrode 112 and the recovery to the fuel electrode 108 side, This is achieved by the cooperation of the porous rotating plate 90 and the porous body 100. The necessary power is only required by the motor that rotates the rotating plate 90, and power consumption can be suppressed. Further, the generated water can be efficiently recovered, and the power generation efficiency of the entire fuel cell system 30 can be maintained high.

  Since the fuel tank unit 40 is not directly related to the present invention, a detailed description thereof is omitted here. The fuel tank unit 40 can be configured to appropriately supply liquid fuel to the porous body 100 on the fuel electrode side using a valve, an injector, or the like using existing technology.

[Second Embodiment]
FIG. 10 shows a plan view of a rotating plate 200 of a fan according to the second embodiment of the present invention. FIGS. 11 and 12 show the rotating plate 200 taken along the alternate long and short dash lines 11-11 and 12-12 in FIG. FIG.

  Referring to FIGS. 10 and 11, the outer annular portion of the rotating plate 200 of the fan according to the present embodiment has four positions that are shifted from each other by 90 degrees as in the rotating plate 90 of the first embodiment. An upward opening 210 for moving the air on the lower surface of the rotating plate 200 to the upper surface of the rotating plate 200 as the rotating plate 200 rotates is formed. The upward opening 210 has an opening 230 on the upper surface side of the rotating plate 200 and an opening 232 on the lower surface side. When the rotating plate 200 rotates in the direction indicated by the arrow 220, the air on the lower surface side of the rotating plate 200 passes through the opening 232 on the lower surface side and the opening 230 on the upper surface side and passes along the path indicated by the flow path 214. Move to the side.

  In the present embodiment, the angle and the diameter of the upward opening 210 are such that the rear edge 236 of the opening 232 on the lower surface side along the rotation direction (arrow 220) of the rotating plate 200 is the opening 230 on the upper surface side. The front edge 234 is selected so as to be located in front of it.

  Similarly, referring to FIG. 10 and FIG. 12, the air on the upper surface of the rotating plate 200 is supplied to the four portions of the inner half of the rotating plate 200 that are shifted from each other by 90 degrees as the rotating plate 200 rotates. A downward opening 212 for moving to the lower surface is formed. The downward opening 212 has an opening 240 on the upper surface side of the rotating plate 200 and an opening 242 on the lower surface side. When the rotating plate 200 rotates in the direction indicated by the arrow 220, the air on the upper surface side of the rotating plate 200 passes through the opening 240 on the upper surface side and the opening 242 on the lower surface side, and along the path indicated by the flow path 216. Move to the side.

  In the present embodiment, the angle and the diameter of the downward opening 212 are such that the rear edge 244 of the upper surface side opening 240 along the rotation direction (arrow 220) of the upper surface side opening 240 is lower than the lower surface side opening 242. The front edge 246 is selected so as to be positioned forward.

  By forming the upward opening 210 and the downward opening 212 in this way, as shown in FIG. 10, there is no portion that can be seen from a direction parallel to the axis from the upper surface to the lower surface of the rotating plate 200. Therefore, there is an effect that water droplets dripping from the air electrode 112 shown in FIG. As a result, the generated water on the surface of the air electrode 112 can be prevented from leaking or evaporating to the space side toward the outside of the fuel cell casing.

  In this embodiment, the current plate as in the first embodiment is not used. However, the present invention is not limited to this embodiment, and a current plate may be used. In this case, the rectifying plate and the opening may be formed so that there is no portion including the rectifying plate that can be seen from the vertical direction of the rotating plate 200 as described above.

[Third Embodiment]
In the first embodiment and the second embodiment, the entire rotating plate 90 and rotating plate 200 of the fan are each formed of a porous body. However, the present invention is not limited to such an embodiment. In the present invention, the rotating plate may be formed so as to reliably absorb water droplets formed on the surface of the air electrode 112.

  Referring to FIG. 13, rotating plate 270 of fan 260 according to the third embodiment is formed on a surface of substrate 280 that is not a porous body and is made of a material that does not transmit moisture, for example, plastic. And a porous layer 282 formed. The surface of the porous layer 282 forms the main surface of the rotating plate 270. In the rotating plate 270, similarly to the rotating plate 90 in the first embodiment, an upward opening and a downward opening are formed at four positions shifted from each other by 90 degrees.

  When the fan 260 employing the rotating plate 270 is provided on the lower surface of the air electrode 112 and rotated, the supply of air to the air electrode 112 and the exhaust of air near the air electrode 112 are performed as in the first embodiment. The absorption of the generated water of the air electrode 112 into the porous layer 282 and the recovery of the fan to the porous body 100 (the peripheral wall portion 102) around the rotating plate 270 by centrifugal force can be performed simultaneously. Further, since a material that does not allow water to pass through is used as the substrate 280, the generated water absorbed from the air electrode 112 into the porous layer 282 leaks or evaporates to the space side toward the outside of the fuel cell housing. Can be suppressed.

[Fourth embodiment]
In the first and second embodiments described above, rotating plates 90 and 200 made of a porous material are used, respectively. In the third embodiment, a rotating plate 270 including a substrate 280 made of a material that does not transmit moisture, such as plastic, and a porous layer 282 formed on the surface of the substrate 280 is used. However, not only such a material but also other materials can be used as the rotating plate of the fan used in the fuel cell system according to the embodiment of the present invention.

  In the fourth embodiment, although not shown, for example, instead of the rotating plate 90 shown in FIG. 5, a rotating plate using a brushed surface and a hygroscopic or water absorbing material is used. Except for the material of the rotating plate, the fuel cell system according to the fourth embodiment has the same configuration as the system 20 according to the first embodiment.

  When a rotating plate made of a brushed water-absorbing or hygroscopic material is used, water generated in the fuel cell is recovered as follows. In the following description, FIG. 5 is referred to as in the first embodiment. However, instead of the rotating plate 90 in FIG. 5, a rotating plate made of a material having water absorption is used.

  Referring to FIG. 5, the air electrode side of the fuel cell includes an air electrode 112 and an air electrode current collector 114 disposed on a part of the lower surface of the air electrode 112. Part or all of the lower surface of the air electrode current collector 114 is subjected to water repellent treatment. The fuel cell is configured such that the lower surface of the air electrode current collector 114 faces the upper surface of the rotating plate (the rotating plate 90 in FIG. 5) with a predetermined distance and is open to a nearby space. A structure and a rotating plate are disposed.

  As the material of the rotating plate, a water-absorbing material having a hygroscopic property or a water-absorbing property in a felt shape, a woven shape, or a non-woven shape may be used. Although not shown in the drawing, such a felt-like, woven-like or non-woven-like material (hereinafter referred to as “water absorption”) is formed on a part or all of the surface of the porous rotating plate 90 used in the first embodiment. May be arranged.

  However, there is a possibility that the rotating plate of the porous body is deformed as the state changes. Therefore, even when the rotating plate is deformed, the water absorbing member is a peripheral wall portion, an air electrode, or a current collector of the surrounding porous body (the peripheral wall portion 102 of the porous 100, the air electrode 112, or the first embodiment). It is necessary to consider the shape of the rotating plate, the shape of the water-absorbing member, and the arrangement site so that the backflow of moisture does not occur by contacting the current collector 114).

  Further, in the rotating plate 270 according to the third embodiment shown in FIG. 13, instead of the porous layer 282 formed on the substrate 280, the material is raised, felt, woven, or non-woven, and absorbs moisture. A water-absorbing member may be used as a water-absorbing member. In order to fix these water-absorbing members to the substrate 280, screws, screws, hook-and-loop fastener structures, or hook structures are used, or the water-absorbing members are sewn to the substrate 280 with chemical-resistant or acid-resistant thread-like members. Alternatively, the water absorbing member may be fixed to the surface of the substrate 280 with a net-like member.

  Furthermore, you may arrange | position the water absorption layer which consists of an above-mentioned water absorption member in all or one part of the surface of the porous layer 282 shown in FIG.

[Fifth embodiment]
In the said embodiment, all the rotating plates have water absorption. However, the present invention is not limited to such an embodiment. The rotating plate is only a substrate made of plastic or the like that does not absorb water, and water droplets adhering to the surface of the substrate fly to a cylinder made of a water-absorbing member around the substrate by centrifugal force due to the rotation of the substrate. It can also be done. Hereinafter, the configuration of the rotating plate of the fuel cell system according to the fifth embodiment of the present invention using the rotating plate having such a configuration will be described.

  Referring to FIG. 14, rotating plate 272 includes a substrate 284 made of plastic or the like that does not transmit moisture or has low moisture transmission. The entire surface of the substrate 284 facing the air electrode is subjected to a hydrophilic treatment, and a hydrophilic layer 286 is formed. The structure of other parts is the same as that of the rotating plate 270 shown in FIG.

  In the fuel cell system according to the present embodiment, moisture generated at the air electrode during operation adheres to the surface of the rotating plate 272. A hydrophilic layer 286 is formed on the surface of the rotating plate 272, and this moisture moves to the peripheral portion of the rotating plate 272 by centrifugal force generated as the rotating plate 272 rotates while adhering to the hydrophilic layer 286. And although not shown in FIG. 14, it flies toward the cylindrical porous body arrange | positioned only a predetermined distance away from the outer periphery of the hydrophilic layer 286, and adheres there. The following movement of moisture is the same as in the first embodiment.

  Note that the hydrophilic layer 286 may be formed only on part of the surface of the substrate 284.

[Sixth Embodiment]
In the fifth embodiment, particularly the example shown in FIG. 14, a hydrophilic layer 286 is formed on the entire surface of the substrate 284 constituting the rotating plate 272. However, the present invention is not limited to such an embodiment. In the hydrophilic layer 286, a water repellent layer may be formed in a portion where moisture scatters toward the periphery, that is, in the vicinity of the peripheral portion of the rotating plate. The rotating plate according to the sixth embodiment has such a configuration.

  Referring to FIGS. 15A and 15B, a rotating plate 292 according to the present embodiment includes a circular substrate 284 made of plastic that does not allow moisture to pass through, and the surface of circular substrate 284 facing the air electrode. And a hydrophilic layer 296 formed over the entire region excluding the peripheral portion. A ring-shaped region where the hydrophilic layer 296 is not formed on the peripheral edge of the surface of the substrate 284 is subjected to water repellent treatment, and a water repellent layer 298 is formed.

  In this way, by forming the water-repellent layer 298 near the outer peripheral portion of the surface of the substrate 284, moisture that has moved the surface of the substrate 284 toward the peripheral portion due to centrifugal force is easily separated from the surface of the substrate 284. There is an effect of becoming.

  Note that the water repellent layer may be formed not only on the peripheral portion of the surface of the substrate 284 but also on the outer peripheral side surface of the substrate 284.

[Seventh Embodiment]
In the fuel cell systems according to the first to sixth embodiments, for example, as shown in FIGS. 6 to 8, an upper portion for sucking air by flowing air from the lower surface to the upper surface side of the rotating plate is provided on the outer peripheral portion. In the vicinity of the central portion of the rotating plate 90, the downward opening portion 132 for exhausting air by flowing air from the upper surface to the lower surface side of the rotating plate 90 is formed. As the rotating plate 90 rotates, intake and exhaust are performed as described above, and supply of air to the air electrode and exhaust from the vicinity of the air electrode are performed.

  However, the configuration of the rotating plate for intake and exhaust in the present invention is not limited to this. For example, when there is the upward opening 130 and air is forcibly supplied from the outside to the air electrode, the exhaust can be performed in a natural manner as the air is supplied. The fuel cell system according to the seventh embodiment uses such a rotating plate.

  FIG. 16 shows a cross-sectional view of a fuel cell system 350 according to the present embodiment. 16 is different from FIG. 4 in that a rotating plate 360 shown in a plan view in FIG. 17 is provided in place of the rotating plate 90 having the structure shown in FIGS.

  Referring to FIGS. 16 and 17, rotating plate 360 is formed of the same material as rotating plate 90 shown in FIG. 4, and is rotated by rotating shaft 94 fixed to the lower surface like rotating plate 90. . However, the rotating plate 360 is formed in the vicinity of the rotation axis at the center of the rotating plate 360 instead of the downward opening 132 shown in FIGS. 6 to 8, and as the rotating plate 360 moves from the upper surface toward the lower surface. A plurality of openings 370 and 372 are formed in such a shape that the distance from the rotation axis is reduced. That is, the distance between the center position of the opening 370 on the lower surface (the back surface of the rotating plate 360) and the rotation center is based on the distance between the center position of the opening 370 on the upper surface (the main surface of the rotating plate 360) and the rotation center. Is also getting bigger. The same applies to the opening 372. By making the orientations of the openings 370 and 372 in this way, the air moving from the upper surface to the lower surface of the rotating plate 360 gathers in the vicinity of the center of the lower surface of the rotating plate 360, and the arrow 164 in FIG. As shown, the air is quickly exhausted from the exhaust port 78 to the outside.

  The opening 370 is formed on a concentric circle around the rotation axis. Similarly, the opening 372 is formed concentrically about the rotation axis. However, the formation position of the opening 372 is closer to the outer periphery of the rotating plate 360 than the position where the opening 370 is formed. Note that the rotating plate 360 is rotated clockwise in FIG. 17 as indicated by an arrow 138 in FIG.

  Since the rotating plate 360 has such openings 370 and 372, in the present embodiment, the intake is forcibly performed as follows, and the exhaust is naturally performed accordingly.

  When the rotating plate 360 rotates in the direction indicated by the arrow 138, the air on the lower surface of the outer peripheral portion of the rotating plate 360 is forcibly moved to the upper surface of the rotating plate 360, as indicated by the arrow 134 in FIG. Along with this, the air pressure on the lower surface of the outer peripheral portion of the rotating plate 360 decreases, and air is taken into the fuel cell system 350 from the outside through the air inlet 80 as indicated by an arrow 162 in FIG. In this way, air is forcibly supplied to the space between the air electrode and the upper surface of the rotating plate 360.

  On the other hand, as described above, the openings 370 and 372 are formed in the vicinity of the center of the rotating plate 360. When air is forcibly supplied to the space between the upper surface of the rotating plate 360 and the air electrode and the air pressure in this portion rises, the air passes from the upper surface of the rotating plate 360 to the lower surface through the openings 370 and 372. Move to. At this time, the positions of the lower surface side openings of the openings 370 and 372 are closer to the center axis of rotation of the rotating plate 360 than the positions of the upper surface side openings. As a result, the air passing through the openings 370 and 372 is collected near the center of the lower surface of the rotating plate 360. Then, the air pressure in this portion rises, and the air in this portion is naturally discharged from the exhaust port 78 to the outside of the casing of the fuel cell system 350 as indicated by an arrow 164 in FIG.

  Note that both the openings 370 and 372 are positioned so that the opening area on the upper surface side and the opening area on the lower surface side of one opening do not overlap each other when viewed from a direction perpendicular to the surface of the rotating plate 360. Is formed. By forming the openings 370 and 372 in this manner, it is possible to prevent water drops dripping from the air electrode from dropping onto the lower surface side through the openings 370 or 372 without adhering to the rotating plate 360 as much as possible. The same applies to the openings in the eighth and ninth embodiments described later.

[Eighth Embodiment]
In the seventh embodiment, the air in the space on the upper surface side of the rotating plate 360 is collected in the vicinity of the center of the lower surface of the rotating plate 360 through the openings 370 and 372, thereby exhausting the air naturally. However, as shown in FIG. 16, the intake port and the exhaust port communicate with each other near the lower surface of the rotating plate 360. As a result, a part of the air supplied through the intake port indicated by the arrow 162 is not supplied to the upper surface of the rotating plate 360, and the exhaust port indicated by the arrow 164 directly at the lower portion of the rotating plate 360. May get mixed in the air to Therefore, the air supply efficiency may be slightly reduced.

  Therefore, in this embodiment, the rotating plate 390 shown in FIGS. 18 and 19 is used to prevent the mixing of the intake air and the exhaust as described above.

  FIG. 18 is a side sectional view of the lower structure of the fuel cell system according to the eighth embodiment of the present invention. FIG. 19 is a plan view of a fan used in this system.

  Referring to FIGS. 18 and 19, rotating plate 390 used in the fan of fuel cell system 380 according to the present embodiment is otherwise related to the seventh embodiment shown in FIGS. 16 and 17. Although the configuration is the same as that of the rotating plate 360, the center of the lower surface of the rotating plate 390 surrounds the lower surface side opening of the rotating plate 390 of the openings 370 and 372 instead of the rotating shaft 94 of the rotating plate 360 shown in FIG. A hollow cylindrical rotary shaft 392 having an upper end bonded thereto, and a rotary shaft 394 fixed to the center of the lower surface of the rotary shaft 392.

  The rotating shaft 392 has a plurality of openings formed in a region desired for the exhaust port 78 at a lower portion of the side surface.

  When the rotating plate 390 rotates, as in the seventh embodiment, ambient air is taken into the housing as indicated by an arrow 162 through the intake port, and the upward opening 130 is formed on the upper surface of the rotating plate 390. Is supplied through.

  Further, a case where a space is provided inside the rotating shaft in the structure for forcibly performing intake and exhausting naturally in the present invention will be described with reference to FIGS. Description of the same structural part is omitted. The difference is the structure of the shaft for rotating the rotating plate, and is that a space for exhausting is provided in the rotating shaft. The air flowing from the intake port 80 side by the air flow generated in the fan structure portion on the intake port side by the rotation of the rotating plate 390 is sent to the air electrode 112 side, passes through the space in the structure of the shaft 392 of the rotating body, and is opened. The air is exhausted into the space inside the rotary shaft 392 through 370 and 372 and further exhausted from the exhaust port to the outside of the housing. At this time, since the space on the lower surface of the rotating plate 390 is divided into the inner side and the outer side by the rotating shaft 392, the air supplied from the intake port directly passes through the upper surface of the rotating plate 390 without passing through the upper surface of the rotating plate 390. It does not get mixed into the air flow to the exhaust port side on the lower surface.

  Therefore, it is possible to provide a fuel cell system that can discharge air in a natural manner while efficiently taking in air and can operate with high efficiency.

[Ninth Embodiment]
In the eighth embodiment described above, the surface of the rotating plate is divided into a region near the center and a region far from the center, and openings 370 and 372 are formed in the region near the center. In this way, it is possible to force intake and exhaust naturally.

  However, the present invention is not limited to such an embodiment. Contrary to the eighth embodiment, the opening on the rotating plate can be formed in such a manner that exhaust is forcibly performed and intake is naturally performed accordingly. Hereinafter, the fuel cell system according to the ninth embodiment will be described.

  FIG. 20 is a side sectional view of the lower structure of the fuel cell system according to the ninth embodiment of the present invention. FIG. 21 is a plan view of a fan used in this system.

  20 and 21, the fuel cell system 400 according to the ninth embodiment of the present invention has the same configuration as the fuel cell system 380 according to the eighth embodiment shown in FIG. ing. However, in this fuel cell system 400, instead of the rotating plate 390 used in the fuel cell system 380 shown in FIG. 18, a mechanism for forcibly exhausting air from the space between the air electrodes, 18 is different from the fuel cell system 380 shown in FIG. 18 in that it includes a rotating plate 410 having a mechanism for naturally supplying air from the outside to a space between the air electrodes along with exhaust.

  Referring to FIGS. 20 and 21, a rotating shaft 412 that divides the lower surface into an outer side and an inner side is attached to rotating plate 410 according to this embodiment, similarly to rotating shaft 392 shown in FIGS. It has been. Further, in the rotating plate 410, as well shown in the plan view shown in FIG. 21, a downward opening 132 is formed in the inner half region of the upper surface of the rotating plate 390, like the rotating plate 90 shown in FIG. ing. A plurality of openings 420 and 422 are formed in the outer half region of the upper surface of the rotating plate 390. The openings 420 are formed at equal intervals on a circumference centered on the center of the rotating plate 410. The openings 422 are also formed at equal intervals on the circumference centered at the same position. However, the distance from the center of the circle to the opening 422 is larger than the distance from the center of the circle to the opening 420.

  The openings of these openings 420 and 422 are closer to the center of the rotating plate 410 on the lower surface than the upper surface of the rotating plate 410.

  Further, notches 430 are also formed on the outer periphery of the rotating plate 410 at regular intervals.

  As is clear from FIG. 21, the lower side of the opening of the downward opening 132 opens toward the space inside the rotating shaft 412. Further, the lower surface side openings of the openings 420 and 422 are located outside the rotation shaft 412.

  In the fuel cell system 400 according to this embodiment, it is assumed that the rotating plate 410 rotates clockwise as indicated by an arrow 138. By the downward opening 132, the air in the space between the upper surface of the rotating plate 410 and the air electrode is discharged into the space defined by the rotating shaft 412 below the rotating plate 410. The air in this portion is further discharged outside the housing of the fuel cell system 400 as indicated by an arrow 164 through an opening formed on the side surface of the rotating shaft 412.

  On the other hand, when the air between the upper surface of the rotating plate 410 and the air electrode is discharged as described above, the air pressure in this portion decreases. As a result, due to a pressure difference from the outside of the casing of the fuel cell system 400, external air flows into the casing of the fuel cell system 400 as indicated by an arrow 162. The air reaches the outer region of the rotating shaft 412 on the lower surface of the rotating plate 410 and flows to the upper surface of the rotating plate 410 through the openings 420 and 422 and the notch 430. At this time, since the positions on the upper surface side of the openings 420 and 422 are closer to the outer periphery than the position on the lower surface side, the air that has passed through the openings 420 and 422 flows toward the outside of the rotating plate 410 and bends upward in the middle. It flows to the downward opening 132 side while contacting the pole surface. The air is forcibly exhausted to the outside through the downward opening 132 and the inside of the rotating shaft 412 as described above.

  Therefore, forced exhaust by the downward opening 132 and natural air supply by the openings 420 and 422 and the notch 430 can be realized.

  In the present embodiment, a notch 430 is provided on the outer periphery of the rotating plate 410. However, the present invention is not limited to such an embodiment. Any configuration can be adopted as long as the air supplied from the outside of the fuel cell system 400 to the outer peripheral portion of the lower surface of the rotating plate 410 efficiently flows to the upper surface of the rotating plate 410. For example, instead of or in addition to providing the notch 430 in the outer periphery of the rotating plate 410 in FIG. 21, a cylindrical shape is provided on the outer peripheral portion of the rotating plate 410 for receiving water scattered around the rotating plate 410. A groove may be formed in the inner wall surface of the porous body 102 in the vertical direction in FIG. 20, and the air on the lower surface of the rotating plate 410 may be supplied to the upper surface side of the rotating plate 410 through the groove. .

  Or you may make it provide the exhaust port penetrated in the external direction in a part of cylindrical porous body 102 shown in FIG.

  In any configuration, air necessary for the operation of the fuel cell system can be efficiently supplied to the upper surface of the rotating plate 410 to the air electrode.

[Modifications related to driving method (applicable to all embodiments)]
In any of the first to ninth embodiments, when power is generated by the fuel cell system, the water in the reaction for power generation and the proton electrolyte from the fuel electrode side to the air electrode side in the power generation process Accompanied water accompanying the movement is generated. Such water appears in the state of water or water vapor from the air electrode side. The amount of moisture differs depending on whether the power is generated at low output or high output, but it is generated as long as the fuel cell system is operated. Therefore, it is necessary to recover and reuse such moisture.

  On the other hand, the amount of air required for power generation is proportionally small at low output and increases at high output. That is, when power is generated at a low output, air supply may be sufficient even when the fan is stopped. Therefore, it may be desirable to operate the fuel cell system with the fan stopped.

  However, in the fuel cell system configured as described above, water cannot be recovered with the rotating body stopped. Therefore, in some form, it is necessary to devise a way to collect moisture during power generation at a low output.

  As one solution, when operating the fuel cell system at a low output, it is conceivable that the water accumulated in the rotating plate is recovered via the cylindrical porous body 102 by intermittently operating the fan. Normally, the output of the fuel cell system can be kept low by stopping the fan. Moisture generated during that time is accumulated on the rotating plate of the fan and is recovered by intermittently operating the fan.

  Further, in order to collect water, it is necessary to rotate the fan rotating plate at a speed equal to or higher than a certain rotational speed to generate a sufficient centrifugal force. However, when operating at a low output, the rotational speed of the fan becomes slow and sufficient centrifugal force may not be generated. In such a case, in order to recover the moisture accumulated on the rotating plate, the rotation speed is sufficiently high considering the water recovery in addition to the slow rotation speed that secures the supply amount of air necessary for power generation. It is advisable to perform switching control between them.

  That is, when operating the above-described fuel cell system at a low output, it is necessary to intermittently provide a period for operating at an output higher than the required output in order to recover water. On the other hand, when generating electricity with the above-described fuel cell system at high output, priority is given to water recovery, and the fan is operated at a rotational speed at which moisture can always be recovered. Thus, air may be supplied in excess by or above the appropriate air volume.

[Other variations]
Although the embodiments of the present invention have been described above, the fan shape and the like are not limited to those employed in the above-described embodiments. A preferable shape can be appropriately selected depending on the design.

  In the above-described embodiment, the fan is provided below the fuel cell structure. However, the present invention is not limited to such an embodiment. As long as the fan satisfies the condition that its rotating plate faces the air electrode of the fuel cell structure and is positioned so that the distance from the air electrode is suitable for absorbing water droplets, It may be provided at any position.

  In the above-described embodiment, the outer casing has a cylindrical shape. This is because it is rational to use a cylindrical shape because the fan is provided inside, and the space around the fan can be used efficiently. However, the present invention is not limited to such an embodiment. The shape of the outer casing may be any shape as long as the fuel cell structure, the fuel cartridge, and the fan can be accommodated therein.

  Moreover, in the said embodiment, nothing processed the surface on the opposite side of the surface which faces an air electrode among the surfaces of a rotating plate. However, the present invention is not limited to such an embodiment. For example, you may make it arrange | position the heat dissipation structure for making it easy to condense generated water on the surface of a rotating plate on this surface.

  The embodiment disclosed herein is merely an example, and the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by each of the claims after taking into account the description of the detailed description of the invention, and all modifications within the meaning and scope equivalent to the wording described therein are intended. Including.

1 is a block diagram of a system 20 including a fuel cell system 30 according to a first embodiment of the present invention. 1 is an external perspective view of a fuel cell system 30. FIG. 2 is a plan view of a fuel cell system 30. FIG. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. It is an expanded sectional view of the fuel cell 42 shown in FIG. 3 is a plan view of a rotating plate 90 of a fan 50 used in the fuel cell system 30. FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6. It is sectional drawing in line 8-8 of FIG. 3 is a cross-sectional view of the fuel cell system 30 for explaining a water recovery path in the fuel cell system 30. FIG. It is a top view of the rotating plate 200 used with the fuel cell system which concerns on the 2nd Embodiment of this invention. It is sectional drawing in line 11-11 of FIG. It is sectional drawing in line 12-12 of FIG. It is a side view of the fan used in the fuel cell system concerning a 3rd embodiment of the present invention. It is a side view of the fan used in the fuel cell system concerning a 5th embodiment of the present invention. It is the side view and top view of a fan which are used in the fuel cell system concerning a 6th embodiment of the present invention. It is a sectional side view of the fuel cell system concerning a 7th embodiment of the present invention. FIG. 17 is a plan view of a fan used in the fuel cell system shown in FIG. 16. It is a sectional side view of the lower structure of the fuel cell system concerning the 8th Embodiment of this invention. It is a top view of the fan used with the fuel cell system shown in FIG. It is a sectional side view of the lower structure of the fuel cell system concerning a 9th embodiment of the present invention. It is a top view of the fan used with the fuel cell system shown in FIG.

Explanation of symbols

  30, 350, 380, 400 Fuel cell system, 32 Power storage device, 34 Load, 36 Control unit, 40, 86 Fuel tank unit, 42 Fuel cell, 50, 260 Fan, 52 Porous body, 54 Fuel, 70 Upper housing 72 Lower housing, 74 Seal member, 76 Air port, 78 Exhaust port, 80 Air intake port, 88 Housing, 90, 200, 270, 272, 292, 360, 390, 410 Rotary plate, 92 Motor, 94 shaft, DESCRIPTION OF SYMBOLS 100 Porous body, 102 Perimeter wall part, 104 Overhang member, 106 Fuel electrode current collector, 108 Fuel electrode, 110 Electrolyte layer, 112 Air electrode, 114 Air electrode current collector, 130, 210 Upward opening part, 132, 212 downward opening, 280, 284 substrate, 282 porous layer, 286, 296 hydrophilic layer, 370, 372, 420, 422 Mouth, 392 axis of rotation, 430 notches

Claims (24)

A fuel cell system using a predetermined liquid fuel as a fuel, comprising a fuel cell structure having a first surface and a second surface,
Water is generated on the first surface of the fuel cell structure along with power generation by the fuel cell, and the predetermined liquid fuel is supplied to the second surface,
The fuel cell system further includes a plate-like member having a main surface disposed at a predetermined distance from the first surface so as to be parallel to the first surface, and the main member of the plate-like member is The surface is made of porous material,
The fuel cell system further includes a rotation driving means for rotating the plate member in a predetermined direction about an axis that intersects the first surface at a right angle. The fuel cell system according to claim 1, wherein the plate-shaped member is a disk-shaped member. The plate-like member is
A substrate having a main surface formed of a material that does not transmit moisture;
A porous layer formed on the main surface of the substrate,
The fuel cell system according to claim 1 or 2, wherein a surface of the porous layer forms the main surface of the plate-like member. The plate member has a back surface parallel to the main surface,
The plate-like member has a first opening penetrating from the back surface to the main surface,
The shape of the first opening is such that the air on the back side is forcibly moved to the main surface side when the plate-like member is rotated about the axis by the rotation driving means. The fuel cell system according to any one of claims 1 to 3, wherein the fuel cell system is selected. 5. The fuel cell system according to claim 4, wherein the plate-like member further has a second opening penetrating from the main surface to the back surface. The shape of the second opening is such that the air on the main surface side is forcibly moved to the back surface side when the plate-like member is rotated around the axis by the rotation driving means. The fuel cell system according to claim 5, which is selected. The shape of the second opening is such that the distance between the center part on the back surface side of the second opening part and the center is larger than the distance between the center part on the main surface side and the center. The fuel cell system according to claim 5, wherein the fuel cell system is selected in shape. The first opening is formed such that a position of the first opening closest to the center of rotation of the plate-like member by the rotation driving unit is a predetermined distance from the center of rotation. And
The said 2nd opening part is formed so that the position farthest from the said rotation center of the said 2nd opening part may become smaller than the said predetermined distance. A fuel cell system according to claim 1. The wall according to claim 8, further comprising a wall member attached at a position of the predetermined distance on the back surface so as to surround the center of the rotation, wherein the wall member bisects the space facing the back surface. The fuel cell system described. The plate member has a back surface parallel to the main surface,
The plate-like member has a first opening penetrating from the main surface to the back surface,
The shape of the first opening is such that the air on the main surface side is forcibly moved to the back surface side when the plate-like member is rotated about the axis by the rotation driving means. The fuel cell system according to any one of claims 1 to 3, wherein the fuel cell system is selected. 11. The fuel cell system according to claim 10, wherein the plate-like member further has a second opening penetrating from the back surface to the main surface. The shape of the second opening is such that the distance between the center on the main surface side of the second opening and the center is larger than the distance between the center on the back side and the center. The fuel cell system according to claim 11, wherein the fuel cell system is selected in shape. The second opening is formed such that a position of the first opening closest to the center of rotation of the plate-like member by the rotation driving unit is a predetermined distance from the center of rotation. And
The first opening is formed so that a position of the first opening farthest from the center of rotation is smaller than the predetermined distance. Fuel cell system. A wall member attached so as to surround the center of rotation at the position of the predetermined distance on the back surface, wherein the space facing the back surface is divided into two by the wall member. The fuel cell system described. The fuel cell system according to any one of claims 10 to 14, wherein a notch having a predetermined size is formed around the plate-like member. The first opening is formed in a shape such that the opening on the main surface side and the opening on the back surface side do not overlap when viewed from a direction perpendicular to the main surface. The fuel cell system according to any one of claims 13 to 13. The second opening is formed in a shape such that the opening on the main surface side and the opening on the back surface side do not overlap when viewed from a direction perpendicular to the main surface. The fuel cell system according to any one of claims 13 to 13. The plate-like member is
A substrate having a main surface formed of a material that does not transmit moisture;
A hydrophilic layer formed on the main surface of the substrate,
The fuel cell system according to claim 1 or 2, wherein a surface of the hydrophilic layer forms the main surface of the plate-like member. The fuel cell system according to claim 18, further comprising a water repellent layer formed on the main surface of the substrate at a predetermined distance from a peripheral edge. The plate-like member is a disc-like member,
2. The fuel according to claim 1, wherein the fuel cell system further includes a cylindrical first porous body disposed around the plate-like member at a predetermined distance from a peripheral edge of the plate-like member. Battery system. The cylindrical first porous body has a first end on the first surface side and a second end on the second surface side,
21. An overhanging portion is formed from the inner periphery of the second end portion of the first porous body so as to project to a position closer to the center of rotation than the periphery of the plate-like member. The fuel cell system described in 1. The fuel cell system is further formed to be continuous with the first end portion of the first porous body, covers the second surface of the fuel cell structure, and the second surface. The fuel cell system according to claim 20 or claim 21, further comprising a second porous body disposed so as to be in contact with the fuel cell. 23. The fuel cell system according to claim 22, further comprising means for supplying the predetermined liquid fuel to the second porous body. The fuel cell system according to any one of claims 1 to 23, wherein the first surface of the fuel cell structure is water-repellent.

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