JP2007165007A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell capable of cutting off effectively supply of fuel when power is not required. <P>SOLUTION: A shutter part 1 which adjusts the quantity of methanol is provided between a fuel holding part and a power generating part in the fuel cell. Two sheets of perforated plates 12, 13 are provided at the shutter part 11 mutually in parallel. A plurality of holes 15, 14 are respectively formed in matrix form in the perforated plates 12, 13. Then, when the fuel cell is operated to generate power, the perforated plate 13 is positioned at a first position in which the holes 14 and the holes 15 are overlapped with each other. On the other hand, when it is not required to operate the fuel cell to generate power, the perforated plate 13 is moved in diagonal direction to the perforated plate 12, that is, in a third row direction 23 with the third shortest sequence cycle of holes 14, and positioned in a second position. Thereby, the distance between the centers of the holes 14 and holes 15 is made as large as possible. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly to a fuel cell including a shutter unit that adjusts the flow rate of fuel supplied from a fuel holding unit to a power generation unit.

  As a power source for small electronic devices such as notebook personal computers, small audio players, and wireless headsets, fuel cells using methanol or the like as fuel are being put into practical use. This methanol fuel cell (DMFC) is a self-breathing fuel cell. That is, this fuel cell is provided with a fuel tank that holds fuel and a power generation unit that generates power, and methanol moves spontaneously from the fuel tank to the power generation unit by capillary action or diffusion phenomenon. Yes. On the other hand, oxygen is taken into the power generation unit from the atmosphere. The power generation unit generates electric power in the process of generating water and carbon dioxide from methanol and oxygen.

  Further, in the fuel cell as described above, when the electronic device is not used, the fuel path from the fuel tank to the power generation unit is shuttered in order to cut off the fuel supply to the power generation unit and suppress the fuel consumption. (See, for example, Patent Document 1).

JP 2004-335314 A

  An object of the present invention is to provide a fuel cell that can effectively cut off the supply of fuel when electric power is not required.

According to one aspect of the invention,
A fuel holding section for holding fuel;
A power generation unit that generates electric power by reacting the fuel supplied from the fuel holding unit with oxygen;
A shutter unit for adjusting the amount of the fuel supplied from the fuel holding unit to the power generation unit;
With
The shutter portion includes first and second perforated plates that are arranged in parallel to each other and each has a plurality of holes formed in the same arrangement.
In each of the first and second perforated plates, the holes are periodically formed along at least two directions;
Among the directions in which periodicity is recognized in the arrangement of the plurality of holes, the arrangement direction having the shortest arrangement period is the first arrangement direction, and the arrangement direction having the second shortest arrangement period is the second arrangement direction. A fuel cell is provided, wherein the first perforated plate is movable relative to the second perforated plate in a direction different from the first and second arrangement directions. Is done.
According to another aspect of the present invention,
A fuel holding section for holding fuel;
A power generation unit that generates electric power by reacting the fuel supplied from the fuel holding unit with oxygen;
A shutter unit for adjusting the amount of the fuel supplied from the fuel holding unit to the power generation unit;
With
The shutter portion includes first and second perforated plates that are arranged in parallel to each other and each has a plurality of holes formed in the same arrangement.
The first perforated plate and the second perforated plate are relatively rotatable,
In each of the first and second perforated plates, a plurality of the holes are arrayed along each of a plurality of array lines extending radially around the central axis of the rotation, and in the adjacent array lines A fuel cell is provided in which distances from the center to the holes are different from each other.

  According to the present invention, it is possible to realize a fuel cell that can effectively cut off the supply of fuel when electric power is not required.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a first embodiment of the present invention will be described.
FIG. 1 is a diagram showing a fuel cell according to this embodiment.
FIG. 2 is a plan view showing the shutter portion in an open state,
FIG. 3 is a plan view showing the shutter portion in a closed state.

As shown in FIG. 1, in the fuel cell 1 according to the present embodiment, a fuel holding unit 2 and a power generation unit 3 are provided.
The fuel holding unit 2 holds methanol and ethanol as fuel, an aqueous solution of sugars such as glucose and sugar, and the power generation unit 3 supplies fuel such as methanol supplied from the fuel holding unit 2 from the atmosphere. It reacts with the oxygen that is taken in to generate electricity. A fuel tank 4 that stores methanol in a liquid state is supplied to the fuel holding unit 2, and methanol is supplied from the fuel tank 4 by a diffusion phenomenon and a capillary phenomenon, and the supplied methanol is vaporized to face the power generation unit 3. And a porous body 5 that is uniformly supplied.
On the other hand, the power generation unit 3 is provided with an anode unit 6, an electrolyte membrane 7, and a cathode unit 8 in order from the fuel holding unit 2 side. The anode unit 6 and the cathode unit 8 are connected to an external device (not shown) that requires electric power. The external device is, for example, an operating part of an electronic device in which the fuel cell 1 is mounted.

  A shutter unit 11 that adjusts the flow rate of methanol supplied from the fuel holding unit 2 to the power generation unit 3 is provided between the fuel holding unit 2 and the power generation unit 3. In the shutter unit 11, the two perforated plates 12 and 13 are provided in parallel so as to overlap each other. The perforated plate 12 is disposed on the fuel holding unit 2 side, and the perforated plate 13 is the power generating unit 3. Arranged on the side. The perforated plates 12 and 13 are provided so as to be relatively movable. For example, the perforated plate 12 is fixed to the other part of the fuel cell 1, and the perforated plate 13 is slidable along the main surface with respect to the perforated plate 12. The perforated plate 13 may be fixed and the perforated plate 12 may be movable, and the perforated plates 12 and 13 are movable in opposite directions with respect to the other portions of the fuel cell 1. It may be said. The perforated plates 12 and 13 are made of, for example, a metal, an alloy, or a resin.

  As shown in FIG. 2, a plurality of holes 14 are formed in the perforated plate 13. The hole 14 penetrates the perforated plate 13. The shape of the hole 14 is, for example, a square when viewed from a direction perpendicular to the surface of the perforated plate 13 (hereinafter referred to as “in plan view”). Furthermore, the holes 14 are arranged in a matrix. That is, they are periodically arranged along two directions orthogonal to each other.

  Of the directions in which periodicity is recognized in the arrangement of the plurality of holes 14, the arrangement direction with the shortest arrangement period is defined as the first arrangement direction 21, and the arrangement direction with the second shortest arrangement period is the second arrangement direction 22. The perforated plate 13 is movable in the third arrangement direction 23 having the third shortest arrangement period. The third arrangement direction 23 is a vector direction obtained by synthesizing a vector directed from the hole 14 toward the nearest hole 14 separated in the first arrangement direction and a vector directed to the nearest hole 14 separated in the second arrangement direction. It is. In other words, when the third arrangement direction 23 forms a virtual rectangle by connecting the centers of the four holes 14 adjacent to each other in the first arrangement direction 21 and the second arrangement direction 22, This corresponds to the direction in which the diagonal line of the rectangle extends.

  In FIG. 2, the perforated plate 12 is hidden behind the perforated plate 13 and is not shown, but the perforated plate 12 also has a hole 15 (see FIG. 2) having the same shape as the hole 14 of the perforated plate 13. 3) is formed in the same arrangement as the holes 14.

  The perforated plate 13 has a first position where the holes 14 overlap the holes 15 in a plan view with respect to the perforated plate 12, and the third arrangement in the third arrangement direction 23 from the first position. A linear movement can be made between the second position separated by half the arrangement period of the holes 14 in the direction 23. FIG. 2 shows a state where the perforated plate 13 is in the first position, and FIG. 3 shows a state where the perforated plate 13 is in the second position. As shown in FIG. 3, when the perforated plate 13 is in the second position, the hole 14 does not overlap with the hole 15 in a plan view but is separated from the hole 15.

Next, the operation of this embodiment will be described.
The fuel tank 4 of the fuel holding unit 2 is filled with, for example, methanol. Then, this methanol spreads uniformly from the fuel tank 4 into the porous body 5 due to the diffusion phenomenon and the capillary phenomenon, reaches the surface of the porous body 5 on the shutter portion 11 side, and is vaporized.

  When the fuel cell 1 generates power, the perforated plate 13 is positioned at the first position with respect to the perforated plate 12 as shown in FIG. Thereby, the hole 15 formed in the perforated plate 12 and the hole 14 formed in the perforated plate 13 overlap in a plan view. That is, the shutter unit 11 is opened. As a result, the flow conductance of methanol in the shutter unit 11 is increased, and the vaporized methanol vapor passes through the holes 15 and 14 and is efficiently supplied to the anode unit 6 of the power generation unit 3.

The anode portion 6 can be formed using a platinum group element simple metal (for example, Pt, Ru, Rh, Ir, Oa, Pd, etc.), an alloy containing a white metal element, or the like. For example, it is desirable to use a Pt—Ru alloy having high resistance to methanol or carbon monoxide, but the present invention is not limited to this. Further, as the material of the anode portion 6, a supported catalyst using a conductive support such as a carbon material can be used.
In the anode unit 6, the methanol and water supplied from the fuel holding unit 2 cause an electrochemical reaction represented by the following chemical formula (1) to generate hydrogen ions (protons) and electrons.

CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ (1)

On the other hand, the cathode portion 8 also uses a platinum group element simple metal (for example, Pt, Ru, Rh, Ir, Os, Pd, etc.), an alloy containing a platinum group element, or a conductive support such as a carbon material. The supported catalyst can be used. The electrolyte membrane 7 can be made of, for example, a fluorine-based resin having a sulfonic acid group, a hydrocarbon-based resin having a sulfonic acid group, or an inorganic substance such as tungstic acid or phosphotungstic acid. Oxygen is taken in from the atmosphere. In addition, protons generated in the anode section 6 are supplied through the electrolyte membrane 7 and electrons are supplied through an external device to cause an electrochemical reaction represented by the following chemical formula (2). Thereby, water is generated. Part of this water passes through the electrolyte membrane 7 and is supplied to the anode unit 6 to be subjected to the reaction of the above chemical formula (1).

1.5O ₂ + 6H ⁺ + 6e ⁻ → 3H ₂ O (2)

When the above chemical formulas (1) and (2) are combined, the power generation unit 3 has a combustion reaction represented by the following chemical formula (3). In the course of this reaction, power can be supplied to the external device. Further, water and carbon dioxide generated by this reaction are discharged to the outside.

CH ₃ OH + 1.5O ₂ → CO ₂ + 2H ₂ O (3)

  On the other hand, when it is not necessary for the fuel cell 1 to generate power, the perforated plate 13 is slid in the third arrangement direction 23 with respect to the perforated plate 12 as shown in FIG. Position. Thereby, the hole 15 formed in the perforated plate 12 and the hole 14 formed in the perforated plate 13 are arranged at positions shifted from each other in plan view. That is, the shutter unit is closed. As a result, the flow conductance of methanol in the shutter portion 11 is reduced, and the flow of methanol from the porous body 5 to the anode portion 6 is suppressed. Thereby, consumption of methanol is suppressed. At this time, the supply of power to the external device is also almost stopped.

Next, the effect of this embodiment will be described.
As described above, in this embodiment, the flow rate of methanol is controlled by sliding the perforated plate 13 with respect to the perforated plate 12 and selecting the relative positional relationship between the holes 14 and 15. is doing. That is, when it is desired to supply methanol to the power generation unit 3, the perforated plate 13 is positioned at the first position, and the holes 14 and 15 are overlapped in plan view. When it is not desired to supply methanol to the power generation unit 3, the perforated plate 13 is positioned at the second position so that the hole 14 and the hole 15 do not overlap in plan view.

  However, in order to smoothly slide the perforated plate 13 with respect to the perforated plate 12, it is necessary to provide a certain amount of clearance (clearance) between the two perforated plates. For this reason, even if the position of the hole 14 is shifted from the position of the hole 15 in plan view, methanol inevitably leaks through the gap between the perforated plates. As a result, methanol is consumed even when it is not necessary to cause the fuel cell 1 to generate power, for example, when an electronic device equipped with the fuel cell 1 is not used. Thereby, the duration of the fuel cell 1 is shortened.

  In view of this, the present inventor has conducted extensive experimental research in order to effectively suppress methanol leakage. As a result, the amount of methanol leakage depends on the distance between the center of the hole 14 and the center of the hole 15 in plan view (hereinafter referred to as the center distance between the upper and lower holes). We found that the amount of leakage was reduced.

FIG. 4 is a plan view showing a shutter portion in a comparative example for explaining the effect of the present embodiment.
As shown in FIG. 4, in this comparative example, the perforated plate 13 is moved in the first arrangement direction 21. In this case, in order to make the distance between the upper and lower hole centers as long as possible with the shutter portion closed, the holes 14 are positioned at an intermediate position between the adjacent holes 15 in the first arrangement direction 21 in plan view. I am letting. At this time, in order to increase the distance L _B between the upper and lower hole centers, it is necessary to increase the arrangement period of the holes 14, but as a result, the number of holes 14 is reduced and the total area of the main surface of the perforated plate 13 is reduced. The ratio of the area of the hole 14 becomes small. In addition, it is conceivable to lengthen the arrangement period of the holes 14 and increase the size of the individual holes 14 to maintain the area ratio of the holes 14, but in this case, the concentration of methanol supplied to the power generation unit 3. Distribution becomes non-uniform.

Therefore, in the present embodiment, the perforated plate 13 is moved in the third direction 23 with respect to the perforated plate 12, as shown in FIG. As a result, the distance between the centers of the upper and lower holes can be increased without increasing the arrangement interval of the holes 14. That is, the distance L _A shown in FIG. 3 can be made longer than the distance L _B shown in FIG. As a result, the leakage of methanol can be blocked more effectively, the consumption of methanol during a period when no power is required can be suppressed, and the duration of the fuel cell 1 can be lengthened.

In the present embodiment, since the shutter portion 11 is formed by overlapping two perforated plates, the shutter portion 11 can be formed in a compact manner. Thereby, the fuel cell 1 can be reduced in size.
Furthermore, in this embodiment, since the shutter unit 11 is disposed between the porous body 5 of the fuel holding unit 2 and the anode unit 6 of the power generation unit 3, the porous unit 5 is porous even when the shutter unit is closed. Methanol is filled up to the surface of the body 5 on the shutter unit 11 side. Therefore, when the shutter unit is opened, methanol is immediately supplied to the power generation unit 3 via the shutter unit 11. For this reason, a delay time (time lag) from when the shutter unit 11 is opened until power is supplied to the external device is short.

  On the other hand, for example, it is conceivable to provide a valve or the like between the fuel tank 4 and the porous body 5 to adjust the flow rate of methanol. However, in this case, although the leakage of methanol can be effectively blocked, there is a problem that the responsiveness of the methanol flow rate to the opening and closing of the valve is low. That is, when the valve is opened, since methanol is supplied to the power generation unit 3 after the inside of the valve mechanism and the porous body 5 is filled, it takes time until the power generation is started. Further, even when the valve is closed, the supply of methanol to the power generation unit 3 is not stopped unless the methanol remaining in the valve mechanism and the porous body 5 is consumed. Moreover, since the volume of the valve mechanism itself is large, the volume of the fuel cell also becomes large.

  Furthermore, in this embodiment, since methanol spreads uniformly in the porous body 5, methanol can be uniformly supplied to the power generation unit 3 in a plane. As a result, variations in the amount of power generation in the plane can be suppressed, and stable power generation with low loss can be achieved.

  As described above, according to the present embodiment, it is possible to effectively prevent leakage of methanol in a state in which the shutter portion is closed, and to obtain a fuel cell that is small and has good responsiveness when the shutter portion is opened and closed. Can do.

Next, a modification of the first embodiment will be described.
FIG. 5 is a plan view showing the shutter portion of the fuel cell according to this modification.
In the shutter portion of this modification, perforated plates 12a and 13a are provided instead of the perforated plates 12 and 13 in the first embodiment. In plan view, the perforated plates 12a and 13a have a pair of sides parallel to the second arrangement direction 22 (see FIG. 2), and the other pair of sides extending from the outer edge 1a of the fuel cell 1. It is a parallelogram parallel to the direction 25 inclined with respect to the direction. A pair of guides 16 are provided in parallel to each other so as to be located inside the outer edge 1a of the fuel cell 1 in plan view. The guide 16 is a rod-like member extending in the direction 25, and grooves (not shown) are formed on the surfaces facing each other, and the cross-sectional shape perpendicular to the longitudinal direction (direction 25) is a U-shape. ing. And a pair of edge part extended in the direction 25 in the perforated board 13a is fitted to the groove | channel of the guide 16 so that a movement is possible.

  The moving member 17 is connected to one of the end portions extending in the second arrangement direction 22 of the perforated plate 13a. The moving member 17 is a rectangular plate-like member whose longitudinal direction extends in the direction 25, one end of which is connected to the perforated plate 13a, and the other end extends outside the outer edge 1a. Thus, when a force is applied along the direction 25 to the other end of the moving member 17, the perforated plate 13 a is guided by the guide 16 and moves in the direction 25. Thus, according to the present modification, the perforated plate can be freely moved in a direction different from the first and second arrangement directions with a simple configuration. Configurations, operations, and effects other than those described above in the present modification are the same as those in the first embodiment described above.

Next, a second embodiment of the present invention will be described.
FIG. 6 is a plan view showing a shutter portion of the fuel cell according to the present embodiment.
In the present embodiment, the holes (for example, the holes 14) are arranged in a staggered pattern in the two perforated plates (for example, the perforated plate 13) constituting the shutter unit. That is, a plurality of holes 14 are periodically arranged along the row direction 34, and a plurality of rows including the holes 14 are arranged along the column direction 35. And between adjacent rows, the phases of the holes 14 are shifted from each other by a half period. Although not shown in FIG. 6, the shape and arrangement of the holes in the perforated plate on the fuel holding unit side are the same as those of the perforated plate 33. In this case, as shown in FIG. 6, the first arrangement direction 21 and the second arrangement direction 22 are different from the above-described row direction 34 and column direction 35. Further, the third arrangement direction 23 coincides with the row direction 34.

  The perforated plate 33 is movable in the third arrangement direction 23 with respect to other portions of the fuel cell. In a plan view, the position where the hole 14 of the perforated plate 33 on the power generation unit side coincides with the hole of the perforated plate on the fuel holding unit side is the first position of the perforated plate 33. The position where 14 is disposed at the intermediate position 36 shown in FIG. 6 is the second position of the perforated plate 33. The intermediate position 36 is an intermediate position between adjacent holes along the third arrangement direction in the perforated plate on the fuel holding unit side. The state where the perforated plate 33 is in the first position is a state where the shutter portion is opened, and the state where the perforated plate 33 is in the second position is a state where the shutter portion is closed. Other configurations in the present embodiment are the same as those in the first embodiment.

  In this embodiment, by moving the perforated plate 33 in the third arrangement direction, the distance between the centers of the upper and lower holes when the shutter portion is closed is set so that the perforated plate 33 is moved in the first or second arrangement direction. It can be made larger than when moved. Thus, according to the present embodiment, even when the holes are arranged in a staggered pattern, the distance between the center of the upper and lower holes in the state where the shutter portion is closed can be increased, and fuel leakage can be effectively suppressed. it can. Operations and effects other than those described above in the present embodiment are the same as those in the first embodiment described above.

Hereinafter, as in the first and second embodiments described above, the movement direction of the perforated plate is the third arrangement direction 23 in which the arrangement period is the third shortest in the arrangement direction of the holes, and the movement distance is the first 3 will be described using a geometric model.
FIG. 7 is a model diagram showing the positional relationship of the holes in the perforated plate.
In this model, holes are represented by dots, and the area and shape of the holes are not considered. A hole is defined as a point A, and among holes separated from the point A in the first arrangement direction 21, a hole closest to the point A is designated as a point B, and separated from the point A in the second arrangement direction 22. Of the holes, the hole closest to the point A is defined as a point C, and the hole closest to the point B among the holes separated from the point B in the second arrangement direction 22 is defined as a point D. Since they are two-dimensionally and periodically arranged along the direction 21 and the second arrangement direction 22, the points A, B, C, and D form a parallelogram ABDC.

At this time, if the angle BAC is an obtuse angle, the direction from the point A to the point D becomes the third arrangement direction 23. This arrangement direction 23 coincides with the direction in which the diagonal line of the parallelogram ABDC extends. When the hole on the opposite side of the point B as viewed from the point A is the point B ₁ and the hole on the opposite side of the point D as viewed from the point C is the point D ₁ , the parallelogram B ₁ ACD ₁ is also parallel. It becomes a parallelogram having the same shape as the quadrilateral ABDC. At this time, the angle B ₁ AC is an acute angle, and the direction from the point A to the point D ₁ is the arrangement direction 24 in which the arrangement period is the fourth shortest.

If the hole located at point A is moved so that it is as far as possible from all of point A, point B, point C, and point D, this hole is located at the center E of the parallelogram ABDC. Just do it. For this purpose, the movement direction of the holes may be the third arrangement direction 23 and the movement distance of the holes may be half the arrangement period in the third arrangement direction 23. The same result can be obtained by moving the hole from the point A to the center E ₁ of the parallelogram B ₁ ACD ₁ . In this case, the movement direction may be the fourth arrangement direction 24 and the movement distance may be half of the arrangement period in the fourth arrangement direction 24. However, in this case, the moving distance becomes longer than when the hole is moved to the center E.

  Thus, according to the above-mentioned model, the hole (for example, hole 14) formed in one holed plate (for example, holed plate 13) is replaced with the other holed plate (for example, holed plate 12). In order to arrange the holes as far as possible from the holes (for example, the holes 15) formed in the plate, the movement direction of the perforated plate is the third arrangement direction 23, and the movement distance is the arrangement period of the third arrangement direction 23. The movement direction may be half, or the movement direction may be the fourth arrangement direction 24, and the movement distance may be half of the arrangement period in the fourth arrangement direction 24. And in order to make the movement distance of a perforated board as short as possible, it should just move to the 3rd arrangement direction 23.

  However, since the above model ignores the shape and area of the hole, other movement methods may be preferable depending on the shape and area of the hole. Further, the above model cannot be applied when the arrangement direction of the holes differs depending on the arrangement positions of the holes in the perforated plate as in a third embodiment described later. However, even in these cases, the movement direction of the perforated plate needs to be different from both the first arrangement direction 21 and the second arrangement direction 22.

Next, a third embodiment of the present invention will be described.
FIG. 8 is a plan view showing a shutter portion of the fuel cell according to the present embodiment.
In the present embodiment, the shape of the perforated plate 43 on the power generation unit side is a disc shape, and the center 42 rotates around the center 42. Further, in the perforated plate 43, a plurality of holes 45 are formed at the same period along a plurality of array lines 44 extending radially from the center 42. The shape of the hole 45 is, for example, a circle. In FIG. 8, the holes 45 are illustrated only in the fan-shaped region corresponding to a part of the perforated plate 43, but actually, the holes 45 are formed in a circular region corresponding to the entire perforated plate 43. ing.

  And the arrangement | sequence of the hole 45 in the adjacent arrangement | positioning line 44 among the several arrangement | sequence lines 44 has the mutually equal period, The phase has shifted | deviated by a half period mutually. That is, when assuming a plurality of concentric circles 47 centered on the center 42 of the perforated plate 43 and arranged at equal intervals when viewed from the center 42, the first array line in which the holes 45 are disposed on the concentric circles 47. 44 and second array lines 44 in which the holes 45 are arranged at the intermediate positions of the adjacent concentric circles 47 are alternately provided. At this time, the first arrangement direction 21 of the holes 45 coincides with the direction (radial direction) in which the arrangement lines 44 extend, and the second arrangement direction 22 extends from a certain hole 45 to the arrangement line 44 to which the holes 45 belong. It belongs to the adjacent array line and coincides with the direction toward the hole 45 formed closer to the center 42 than the hole 45. The movement direction of the holes 45 is different from the first arrangement direction 21 and the second arrangement direction 22 and coincides with the circumferential direction 48.

  Although not shown in FIG. 8 because it is behind the perforated plate 43, the shutter portion is also provided with a perforated plate on the fuel holding portion side, and a hole is also formed in the perforated plate. Has been. The shape and arrangement of the holes formed in the perforated plate on the fuel holding part side are the same as those of the perforated plate 43. The perforated plate on the fuel holding part side is fixed to the other part of the fuel cell. Thus, the two perforated plates are relatively rotated. Other configurations in the present embodiment are the same as those in the first embodiment.

Next, the operation of this embodiment will be described.
When opening the shutter unit, the hole 45 of the perforated plate 43 on the power generation unit side is overlapped with the hole of the perforated plate on the fuel holding unit side in plan view. Thereby, methanol which is a fuel is supplied to a power generation part through the hole of a perforated plate. On the other hand, when closing the shutter portion, the perforated plate 43 is rotated with respect to the other portions of the fuel cell with the center 42 as the rotation center. Thereby, the hole 45 is located in the position spaced apart in the circumferential direction from the hole of the perforated plate on the fuel holding unit side in a plan view. For example, the hole 45a is positioned at the position 46a. Thereby, supply of fuel is interrupted and power generation is stopped. Operations other than those described above in the present embodiment are the same as those in the first embodiment described above.

Next, the effect of this embodiment will be described.
FIG. 9 is a plan view showing a shutter portion in a comparative example for explaining the effect of the present embodiment.
As shown in FIG. 9, in this comparative example, the holes 45 are arranged in the same period and the same phase in all the arrangement lines 44 of the perforated plate 53. That is, in all the array lines 44, the holes 45 are formed at the intersections between the array lines 44 and the concentric circles 47. In this case, the second arrangement direction 22 of the holes 45 coincides with the movement direction of the holes 45, that is, the circumferential direction 48. For this reason, even if the perforated plate 53 is rotated, the distance between the holes (distance between the upper and lower holes) cannot be increased between the two perforated plates.
On the other hand, according to the present embodiment, as shown in FIG. 8, the movement direction of the holes 45 is different from both the first arrangement direction 21 and the second arrangement direction 22. When the part is closed, the distance between the centers of the upper and lower holes can be increased. Thereby, leakage of fuel when the shutter portion is closed can be effectively suppressed.

  Further, in the present embodiment, the position of the hole is not caused by the parallel movement of the perforated plate but by the rotational motion about the center of the perforated plate as the rotational center as in the first and second embodiments described above. Is shifted. For this reason, the outer shape of the shutter portion is not changed by the movement of the perforated plate, and the outer shape of the perforated plate can be made substantially the same as the outer shape of the shutter portion. Thereby, the shutter part can be further miniaturized, and the fuel cell can be miniaturized. The effects of the present embodiment other than those described above are the same as those of the first embodiment described above.

Next, a fourth embodiment of the present invention will be described.
FIG. 10 is a plan view showing a shutter portion of the fuel cell according to the present embodiment.
In the present embodiment, compared to the third embodiment described above, in the perforated plate 54, the plurality of concentric circles 55 are not equally spaced from each other as viewed from the center 56 of the perforated plate 54, but as the distance from the center 56 increases. The difference is that the distance between them is assumed to be narrow. Thereby, in each arrangement line 44, the distance between the holes 57 becomes narrower as the distance from the center 56 increases. As a result, the arrangement density of the holes 57 formed in the perforated plate 54 can be made uniform in the plane.

  Also in this embodiment, similarly to the third embodiment described above, the first array line 44 in which the holes 57 are arranged on the concentric circles 55 and the holes 57 are arranged at the center positions of the adjacent concentric circles 55. The second array lines 44 are alternately provided. As a result, when the two perforated plates are relatively rotated with the center 56 as the center of rotation, the distance between the holes (the distance between the upper and lower hole centers) is increased between the two perforated plates. And leakage of fuel when the shutter portion is closed can be effectively suppressed. For example, when the perforated plate 54 is rotated along the circumferential direction 48, the hole 57a moves to the position of the hole 58a, but the position of the hole 58a is far from any of the holes 57.

  According to the present embodiment, since the arrangement density of the holes 57 is more uniform in the plane in the shutter portion, the fuel can be uniformly supplied to the power generation portion with a face piece. Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the third embodiment described above.

In each of the above-described embodiments, an example in which the shape of the hole is a square or a circle is shown. However, the present invention is not limited to this and may have any shape. However, it is preferable that the holes formed in the two perforated plates coincide with each other in plan view when the shutter portion is opened.
Further, the shape of the perforated plate is not limited to a rectangle, a parallelogram, and a circle. For example, the outer shape of the fuel cell may be determined from a design requirement of an electronic device on which the fuel cell is mounted, and the outer shape of the perforated plate may be determined based on the outer shape of the fuel cell.
Further, in each of the above-described embodiments, an example in which the perforated plate is formed from a metal or an alloy has been shown. However, the present invention is not limited to this, and the perforated plate may be formed from a resin. Thereby, the cost can be reduced. However, as shown in the above chemical formula (3), carbon dioxide is generated in the power generation unit of the fuel cell, and thus the internal pressure of the power generation unit may be higher than the atmospheric pressure. For this reason, it is preferable that the perforated plate has a certain degree of rigidity so that the perforated plate is not deformed by the internal pressure.

Furthermore, in each of the embodiments described above, an example in which methanol is used as the fuel has been shown. However, the present invention is not limited to this, and any fuel cell that uses liquid or gaseous fuel may be used. Anything is applicable.
Furthermore, the material, size, shape, arrangement relationship, etc., of each element constituting the fuel cell of the present invention may be modified as appropriate by those skilled in the art as long as it includes the gist of the present invention. It is included in the scope of the invention.

  Hereinafter, the effect of the Example of this invention is demonstrated, comparing with a comparative example.

(Test Example 1)
In Test Example 1, when a pair of perforated plates having holes formed in a matrix is used and the relative movement direction of the perforated plates is set as the first arrangement direction (Comparative Example), The case of the arrangement direction (Example) was compared by simulation.
FIG. 11 is a plan view showing a perforated plate used in this test example,
FIG. 12 is a plan view showing each hole,
13 (a) and 13 (b) are plan views showing changes in the positional relationship between the holes as the perforated plate moves, (a) showing a comparative example, and (b) showing an example of the present invention. Indicates.
FIG. 14 is a cross-sectional view showing a fuel flow path,
FIG. 15 is a perspective view thereof.
FIG. 16 is a graph showing the influence of the distance between the holes on fuel leakage, with the horizontal axis representing the distance between the upper and lower hole centers and the vertical axis representing the fuel outlet concentration and outlet flux.
FIG. 17 is a graph showing the influence of the distance between the holes on the fuel leakage, with the horizontal axis representing the distance between the upper and lower hole centers and the vertical axis representing the fuel outlet concentration.
In addition, although the dimension of the principal part is described in FIG.11 and FIG.12, all a unit is a millimeter (mm).

As shown in FIGS. 11 and 12, in the simulation of this test example, two perforated plates 61 each having a plurality of oval holes 62 arranged in a matrix are provided and arranged in parallel to each other. did. The thickness of each perforated plate 61 was 0.5 mm, and the distance between the two perforated plates 61 was 0.2 mm.
The number of holes 62 was 15 in the X direction and 6 in the Y direction, for a total of 90 (= 15 × 6). The distance between the centers of the holes 62 in the X direction was 4.3 mm, and the distance between the centers of the holes 62 in the Y direction was 9.5 mm. Accordingly, the distance between the centers of the holes 62 located at both ends in the X direction of the perforated plate 61 is 60.2 mm (= 4.3 mm × 14), and the holes 62 located at both ends in the Y direction of the perforated plate 61. The distance between the centers is 47.5 mm (= 9.5 mm × 5).
The shape of the hole 62 is a longitudinal direction (an oblong shape in which both ends of the Y direction 9 are rounded.) The length of the hole 62 in the X direction is 1.5 mm, and the length in the Y direction is 6.5 mm. did.

  When the plurality of holes 62 are formed in the perforated plate 61 as described above, the first arrangement direction of the holes 62, that is, the arrangement direction with the shortest arrangement period is the X direction, and the second arrangement direction, that is, the arrangement period is The second shortest arrangement direction is the Y direction. The third arrangement direction is the direction of a vector obtained by combining the vector directed to the nearest hole 62 separated from the certain hole 62 in the X direction and the vector directed to the nearest hole 62 separated in the Y direction, that is, the diagonal direction. Matches.

  As shown in FIG. 13A, in the comparative example, the hole 62 formed in one of the perforated plates 61 and the hole 62 formed in the other perforated plate 61 overlap in plan view. On the basis of the state, that is, the state where the distance between the upper and lower hole centers is zero, one perforated plate 61 is moved in the first arrangement direction 21 (X direction) with respect to the other perforated plate 61, The distance between centers was set to 1.50 mm, 1.72 mm, 1.93 mm and 2.15 mm, and the leakage state of methanol at that time was simulated. When the distance between the upper and lower hole centers is 2.15 mm, the distance between the upper and lower hole centers is half of the arrangement period in the first arrangement direction, and the holes 62 formed in one of the perforated plates 61. Is the case where the other perforated plate 61 is located at an intermediate position between two holes 62 adjacent to each other in the X direction.

  On the other hand, as shown in FIG. 13 (b), in the embodiment of the present invention, one perforated plate 61 is placed with respect to the other perforated plate 61 on the basis that the distance between the upper and lower hole centers is zero. It was moved in the third arrangement direction 23, and the distance between the upper and lower hole centers was made half of the arrangement period in the third arrangement direction 23. And the leakage state of methanol at that time was simulated.

Hereinafter, the boundary conditions of this simulation will be described.
The methanol concentration at the boundary of the shutter portion on the fuel holding portion side was set to 7.533 mol / m ³ assuming a saturated state. Further, the movement resistance of methanol at the boundary on the power generation unit side was {(diffusion coefficient / (12.5 mm)}, and the environmental concentration, that is, the methanol concentration at a position 12.5 mm away, was 0 mol / m ³ . 14 and 15, a methanol flow path 70 is formed, and the concentration of methanol (outlet concentration) and the methanol flux at the outlet of the shutter, that is, the end on the power generation unit side. (Outlet flux) was calculated, and the calculation results are shown in FIGS.

  FIG. 16 is a diagram illustrating a simulation result of the comparative example. As shown in FIG. 16, among the comparative examples, the greater the distance between the center of the upper and lower holes, the smaller the outlet concentration and outlet flux of methanol, and a tendency to suppress leakage was observed. However, in the comparative example, the distance between the upper and lower hole centers is 2.15 mm at the maximum, that is, only half of the arrangement period in the first arrangement direction can be taken, so that the effect of suppressing methanol leakage is insufficient. It was a thing.

  FIG. 17 is a diagram illustrating simulation results of the example of the present invention and the comparative example. As shown in FIG. 17, according to the embodiment of the present invention, the distance between the center of the upper and lower holes can be increased, and the outlet concentration of methanol can be greatly reduced. That is, methanol leakage was sufficiently suppressed.

(Test Example 2)
In Test Example 2, a pair of perforated plates in which holes are formed in a matrix or a staggered pattern are used, and the relative movement direction of the perforated plates is matched with the first arrangement direction (comparison) Example) and a case where the first and second arrangement directions are not matched (Example) were compared by simulation. Table 1 shows the simulation conditions.

18 (a) to 18 (c) are perspective views showing the flow path of methanol formed in this test example, and FIG. 1 and (b) shows Example No. 2 (c) shows Example No. 3 is shown.
19 (a) to 19 (c) are graphs showing the simulation results of the methanol concentration in each part of the methanol flow path shown in FIG. 1 and (b) shows Example No. 2 (c) shows Example No. 3 is shown.
Further, FIG. 20 is a graph showing the leakage state of methanol with the abscissa indicating the simulation condition and the ordinate indicating the outlet concentration and outlet flux of methanol.

  In this test example, the shape of the hole was square in plan view, and the length of one side was 2 mm. Moreover, the space | interval between adjacent holes was 2 mm in both the X direction and the Y direction. However, this interval is not the distance between the centers, but the distance between the edges facing each other. As in the first test example described above, the thickness of the perforated plates was 0.5 mm, and the interval between the perforated plates was 0.2 mm. Furthermore, the boundary conditions of the simulation were the same as in the first test example described above.

As shown in Table 1 and FIG. In No. 1, holes were formed in a matrix on the perforated plate. That is, the holes were periodically arranged along the X direction and the Y direction. Both hole arrangement periods were 4 mm. At this time, the first and second arrangement directions are the X direction and the Y direction. Then, the perforated plate was moved 2 mm in the X direction, that is, in the first arrangement direction, based on the state in which the shutter portion is open, that is, the state in which the distance between the upper and lower hole centers is 0.
Further, as shown in Table 1 and FIG. In No. 2, holes were formed in a perforated plate in a staggered pattern. That is, the holes were arranged in a cycle of 4 mm along the Y direction, and a plurality of rows of holes extending in the Y direction were arranged along the X direction. Then, the phase of the hole arrangement was shifted by half a cycle between adjacent rows. At this time, the first arrangement direction is the Y direction. Then, the perforated plate was moved 2 mm in the X direction on the basis of the state where the shutter portion was open. This moving direction does not coincide with any of the first to fourth arrangement directions.
Furthermore, Example No. In No. 3, holes were formed in a matrix on the perforated plate. That is, the holes were periodically arranged along the X direction and the Y direction. Both hole arrangement periods were 4 mm. At this time, the first and second arrangement directions are the X direction and the Y direction. Then, the perforated plate was moved 2 mm in the X direction and 2 mm in the Y direction with reference to the state where the shutter portion was open. This movement direction coincides with the third arrangement direction.

The simulation results are shown in FIGS. 19 (a) to 19 (c) and FIG. In FIG. 19 (a) ~ (c) , the region a, the concentration of methanol showed an area of less than 7.2 mol / ^{m 3} or more 7.6mol / ^{m 3,} region b is the concentration of methanol 6.0mol / M ³ or more and less than 7.2 mol / m ³ is shown, region c is a region where the concentration of methanol is 5.8 mol / m ³ or more and less than 6.0 mol / m ³ , and region d is methanol A region having a concentration of 4.6 mol / m ³ or more and less than 5.8 mol / m ³ is shown, and a region e shows a region having a methanol concentration of 4.2 mol / m ³ or more and less than 4.6 mol / m ³ .

19A to 19C, the island-shaped region a corresponds to a region directly above the opening of the lower perforated plate. In addition, the band-like region a on the left side in the drawing is a region where the concentration of methanol is increased because the perforated plate is no longer disposed by moving the perforated plate. And the some convex part shown in FIG. 19 has shown the inside of an upper perforated board (not shown), and it can be said that the leakage of methanol is suppressed, so that the methanol concentration of this part is low.
As shown in FIG. In 1, the four convex portions belonging to the rightmost column in the figure are regions d, and the other 12 convex portions are regions b.
On the other hand, as shown in FIG. In FIG. 2, the four convex portions belonging to the rightmost column in the figure are comparative example Nos. Although it is the area | region d similarly to 1, the area | region c exists in three convex parts among the other 12 convex parts, and the area | region d exists in one convex part among them. For this reason, Example No. 2 is Comparative Example No. Compared to 1, it can be said that methanol leakage is suppressed.
In addition, as shown in FIG. 3, one of the four convex portions belonging to the rightmost column in the figure is an area e. Of the other 12 convex portions, three convex portions are regions d, and the remaining nine convex portions also have a region c. Therefore, Example No. 3 is the same as in Example No. It can be seen that the leakage of methanol in the shutter portion is further suppressed as compared to 2.

  Further, as shown in FIG. 2 is Comparative Example No. The outlet concentration and outlet flux of methanol are lower than those in Example 1. 3 is an example No. 3; The outlet concentration and outlet flux of methanol were lower than 2.

  Thus, Example No. 2 and no. 3 is Comparative Example No. Methanol leakage was more effectively suppressed than 1. In addition, Example No. 1 in which the moving direction of the perforated plate is the third arrangement direction. In Example 3, the perforated plate arrangement direction was not matched with the third and fourth arrangement directions. Methanol leakage was more effectively suppressed than 2.

1 is a diagram showing a fuel cell according to a first embodiment of the present invention. It is a top view which shows the shutter part in the open state. It is a top view which shows the shutter part in a closed state. It is a top view which shows the shutter part in a comparative example. It is a top view which shows the shutter part of the fuel cell which concerns on the modification of this 1st Embodiment. It is a top view which shows the shutter part of the fuel cell which concerns on the 2nd Embodiment of this invention. It is a model figure which shows the positional relationship of the hole in a perforated board. It is a top view which shows the shutter part of the fuel cell which concerns on the 3rd Embodiment of this invention. It is a top view which shows the shutter part in a comparative example. It is a top view which shows the shutter part of the fuel cell which concerns on the 4th Embodiment of this invention. 3 is a plan view showing a perforated plate used in Test Example 1. FIG. It is a top view which shows each hole. (A) And (b) is a top view which shows the change of the positional relationship between the holes accompanying the movement of a perforated board, (a) shows a comparative example, (b) shows the Example of this invention. . It is sectional drawing which shows the distribution route of fuel. FIG. It is a graph which shows the influence which the distance between holes exerts on the fuel leakage, taking the distance between the center of the upper and lower holes on the horizontal axis and the outlet concentration and outlet flux of the fuel on the vertical axis. It is a graph which shows the influence which the distance between holes has on the fuel leakage by taking the distance between the center of an upper and lower hole on a horizontal axis, and taking the fuel exit concentration on a vertical axis. (A)-(c) is a perspective view which shows the distribution channel of methanol formed in Test Example 2, (a) Comparative example No. 1 and (b) shows Example No. 2 (c) shows Example No. 3 is shown. (A)-(c) is a figure which shows the simulation result of the methanol density | concentration in each part of the distribution route of methanol shown in FIG. 1 and (b) shows Example No. 2 (c) shows Example No. 3 is shown. It is a graph which shows the leakage state of methanol, taking the simulation conditions on the horizontal axis and taking the outlet concentration and outlet flux of methanol on the vertical axis.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell, 1a outer edge, 2 Fuel holding part, 3 Power generation part, 4 Fuel tank, 5 Porous body, 6 Anode part, 7 Electrolyte membrane, 8 Cathode part, 11 Shutter part, 12, 12a, 13, 13a, 33 , 43, 53, 54, 61 perforated plate, 14, 15, 45, 45a, 46a, 57, 57a, 58a, 62 hole, 16 guide, 17 moving member, 21 first arrangement direction, 22 second Arrangement direction, 23 third arrangement direction, 24 fourth arrangement direction, 25 direction, 34 row direction, 35 column direction, 36 intermediate position, 42, 56 center, 44 arrangement line, 47, 55 concentric circle, 48 circumferential direction , 70 Distribution channel, A, B, B ₁ , C, D, D ₁ point, E, E ₁ center, a, b, c, d, e area

Claims (9)

A fuel holding section for holding fuel;
A power generation unit that generates electric power by reacting the fuel supplied from the fuel holding unit with oxygen;
A shutter unit for adjusting the amount of the fuel supplied from the fuel holding unit to the power generation unit;
With
The shutter portion includes first and second perforated plates that are arranged in parallel to each other and each has a plurality of holes formed in the same arrangement.
In each of the first and second perforated plates, the holes are periodically formed along at least two directions;
Among the directions in which periodicity is recognized in the arrangement of the plurality of holes, the arrangement direction having the shortest arrangement period is the first arrangement direction, and the arrangement direction having the second shortest arrangement period is the second arrangement direction. The fuel cell according to claim 1, wherein the first perforated plate is movable relative to the second perforated plate in a direction different from the first and second arrangement directions.   The first perforated plate is formed on the first perforated plate as viewed from a direction perpendicular to the surface of the first perforated plate with respect to the second perforated plate. Between the first position where the hole and the second hole formed in the second perforated plate overlap, and the second position where the first hole and the second hole do not overlap. The fuel cell according to claim 1, wherein the fuel cell is relatively movable.   The direction of relative movement of the first perforated plate with respect to the second perforated plate is a third arrangement direction having the third shortest arrangement period among the directions in which the periodicity is recognized, The fuel cell according to claim 2, wherein the distance of movement is half of the third shortest arrangement period.   4. The fuel cell according to claim 3, wherein the plurality of holes are arranged in a matrix in each of the first and second perforated plates.   4. The fuel cell according to claim 3, wherein the plurality of holes are arranged in a staggered pattern in each of the first and second perforated plates. The first perforated plate and the second perforated plate are relatively rotatable,
In each of the first and second perforated plates, the plurality of holes are periodically arranged along a plurality of array lines extending radially about the center axis of the rotation, and are adjacent to each other. 3. The fuel cell according to claim 1, wherein, in the array line, the array periods of the holes are equal to each other, and the phase is shifted by a half period. A fuel holding section for holding fuel;
A power generation unit that generates electric power by reacting the fuel supplied from the fuel holding unit with oxygen;
A shutter unit for adjusting the amount of the fuel supplied from the fuel holding unit to the power generation unit;
With
The shutter portion includes first and second perforated plates that are arranged in parallel to each other and each has a plurality of holes formed in the same arrangement.
The first perforated plate and the second perforated plate are relatively rotatable,
In each of the first and second perforated plates, a plurality of the holes are arrayed along each of a plurality of array lines extending radially around the central axis of the rotation, and in the adjacent array lines The fuel cell is characterized in that the distance from the center to each of the holes is different from each other.   The distance between the holes along each of the array lines in each of the first and second perforated plates is large near the center and small far from the center. Fuel cell. The fuel holding part has a porous body,
The power generation unit has an anode unit that generates hydrogen ions and electrons by decomposition of the fuel,
The fuel cell according to claim 1, wherein the shutter portion is provided adjacent to the porous body and the anode portion.