JP2011054447A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell capable of stably generating power and maintaining a high power generating efficiency and moreover suppressing drying-up of a power generation part. <P>SOLUTION: In the power generating part of a fuel cell of a natural aspiration type, barrier ribs 33 are provided opposed to an oxidant electrode 31 with a space interposed, a first communication port 371 and a second communication port 372 arranged near each of a first end part 361 and a second end part 362 lower than the first end part 361 respectively, and while diffusion of vapor toward a perpendicular direction to the oxidant electrode 31 is prevented, the air as a fuel is supplied from the second communication port 372 by thermal convection during power generation, and since the air after power generation is exhausted from the first communication port 371, a stable power generation is made possible and while a high power generation efficiency is maintained, dry-up of the power generation part 1 can be suppressed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell used as an internal power source for an external load.

  Currently, secondary batteries typified by lithium ion batteries are mainly used as power sources for electronic devices such as notebook computers and mobile phones. However, with the demand for further extension of the usage time of these electronic devices and the recent enhancement of functionality of electronic devices, the use of fuel cells that are high in output and do not require charging is expected. There are many types of fuel cells, but solid polymer fuel cells are promising for fuel cells used in the above-mentioned electronic devices because the system can be easily downsized and simplified. is there.

  In a polymer electrolyte fuel cell, power is generated by supplying fuel to the fuel electrode and oxygen in the air to the oxidizer electrode. At this time, protons that have moved from the fuel electrode into the solid polymer membrane combine with oxygen at the oxidant electrode to generate water. The water produced at the oxidant electrode is retained in the solid polymer film, but most of it evaporates into the air supplied to the oxidant electrode. Also, water is necessary for protons to move through the solid polymer membrane, but the power generation section becomes hot due to the heat generated by the fuel cell during power generation, for example, dry-up that reduces the humidity of the oxidant gas. (Dry-out) occurs and power generation performance decreases. Therefore, the power generation unit needs to maintain a certain humidity.

  Therefore, a technique has been proposed that does not cause dry-up by forcibly supplying air to the oxidizer electrode using a fan, improving heat dissipation performance, and preventing the power generation unit from becoming high temperature (for example, Patent Document 1).

  However, in the configuration described in Patent Document 1, electric power is required to operate the fan, and it is necessary to supply the electric power from the fuel cell or the secondary battery, so that the power generation efficiency of the fuel cell system is reduced. End up.

  In addition, as a technique for preventing dry-up of the power generation unit without using electric power, it is provided with a U-shaped condensation means that protrudes from the oxidizer electrode and is provided on the catalyst layer to condense water vapor, thereby increasing the water vapor pressure in the coating region. The technique which performs is proposed (for example, patent document 2).

JP2007-95581A JP2008-198385A

  However, in the configuration of Patent Document 2, the dew condensation means that condenses water vapor covers a part of the catalyst layer of the fuel, and the supply of air to the fuel electrode is obstructed, and particularly a large amount of fuel is required. Under the high current density condition, the power generation efficiency is lowered.

  Therefore, the present invention has been made in view of the above points, and an object thereof is to provide a fuel cell capable of stable power generation and capable of suppressing dry-up of a power generation unit while maintaining high power generation efficiency. And

  In order to solve the above-described problem, a first feature of the fuel cell of the present invention is that the fuel cell, the oxidant electrode, the fuel electrode and the power generation unit composed of the electrolyte membrane sandwiched between the oxidant electrode and the atmosphere communicate with each other. The fuel cell has a communication port, and air in the atmosphere is supplied to the oxidant electrode as natural oxidant via the communication port by natural intake, and the oxidant electrode and the electrolyte membrane of the oxidant electrode are disposed. And an oxidant electrode portion having a space formed by the oxidant electrode and the partition wall, the oxidant electrode side portion including a first end, A second end opposite to the first end, the first end being provided at a position higher than the second end, and the first end and the second end At least one first communication port near the first end from the center of the center, and at least near the second end from the center of the first end and the second end One second communication port of the gist that comprises a.

  According to such a feature, in the oxidant electrode of the naturally aspirated fuel cell, the communication port is provided at the inlet and the outlet of the air flow rising by thermal convection, so that sufficient supply of air and exhaust are ensured, The partition walls can prevent water vapor from diffusing into the atmosphere perpendicular to the electrolyte membrane. Therefore, it is possible to suppress dry-up during power generation while maintaining high power generation performance.

  According to a second aspect of the fuel cell of the present invention, in the fuel cell according to the first aspect, a hydration unit that supplies water to the oxidant electrode is provided on a side of the second end portion. The gist.

  According to this feature, the humidity of the oxidant electrode can be kept high by supplying water to the oxidant electrode from the air supply side communication port.

  The gist of a third feature of the fuel cell of the present invention is that, in the fuel cell of the second feature, the hydration means includes an evaporating part for evaporating water supplied from the water storage part.

  According to such a feature, dry-up can be suppressed for a long time because the water provided in the water reservoir is evaporated as water vapor.

  According to a fourth aspect of the fuel cell of the present invention, in the fuel cell according to the third aspect, the hydration unit includes a heating unit, and the evaporation unit is heated by the heating unit.

  According to such a feature, the evaporation means is kept at a high temperature by the heating means, and more water can be evaporated. Therefore, it is possible to more effectively suppress the dry-up.

  According to a fifth feature of the fuel cell of the present invention, in the fuel cell of the fourth feature, the heating means is a heat transfer body that transfers heat generated in the power generation section to the evaporation section during power generation. The gist.

  According to this feature, since the heating means uses heat generated during power generation by the power generation unit, energy is not specifically used to increase the temperature of the evaporation unit, so that dry-up can be suppressed with low energy. Can do.

  According to a sixth feature of the fuel cell of the present invention, in the fuel cell according to any one of the third to fifth features, the hydrating means has a heat insulating means on a surface in contact with the atmosphere other than the evaporation section. The gist.

  According to this feature, since the heat energy given to the hydration means is used only for the evaporation of water, the dry-up can be suppressed with a lower energy.

  A seventh feature of the fuel cell of the present invention is that, in the fuel cell according to any one of the third to sixth features, the evaporation portion is a surface having one or more raised shapes on the surface. To do.

  According to such a feature, the surface area of the evaporating part is large, and a large area where water per unit area of the evaporating part can evaporate can be ensured. Therefore, the effect of suppressing dry-up can be obtained by a small hydration means. .

  According to an eighth feature of the fuel cell of the present invention, in the fuel cell according to any one of the third to seventh features, a detection unit that detects the temperature of the power generation unit is provided, and the detection value obtained by the detection unit. The gist of the present invention is to provide a control unit for controlling the hydration means so that the water is evaporated in the evaporation unit when the value is equal to or greater than a predetermined value.

  According to this feature, the control unit controls the evaporation unit to evaporate water when the power generation unit is in a dry-up state based on the temperature information obtained by the detection unit. Therefore, since water does not evaporate in a state where it is not dry-up, an efficient dry-up suppressing effect that does not require wasteful energy can be obtained.

  According to the present invention, stable power generation is possible, and dry-up of the power generation unit can be suppressed while maintaining high power generation efficiency.

1 is a schematic view of a fuel cell according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a region indicated by a dotted line in FIG. 1. FIG. 2 is a schematic cross-sectional view of a region indicated by a broken line in FIG. 1. It is the other example of installation of the communicating port of 1st Embodiment of this invention. It is the other example of installation of the communicating port of 1st Embodiment of this invention. It is the schematic of the fuel cell which concerns on 2nd Embodiment of this invention. It is the schematic of the fuel cell which concerns on 3rd Embodiment of this invention. It is the schematic of the fuel cell which concerns on 4th Embodiment of this invention. It is the schematic of one specific example of an evaporation part. It is the schematic of the fuel cell which concerns on 5th Embodiment of this invention.

[First Embodiment]
A fuel cell according to a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic diagram of a fuel cell according to a first embodiment of the present invention, FIGS. 2 and 3 are cross-sectional views of FIG. 1, and FIGS. 4 and 5 are diagrams of another embodiment of the present embodiment shown in FIG. The outline is shown.

  As shown in FIG. 1, the power generation unit 1 is configured by sandwiching an electrolyte membrane 11 provided in a vertical direction between a fuel electrode part 2 including a fuel electrode 21 and an oxidant electrode part 3 including an oxidant electrode 31. It is a structure. The electrolyte membrane 11 is preferably arranged in the vertical direction, but is not limited to use in this posture. That is, a user of a device equipped with a fuel cell can be used so that the fuel cell is temporarily tilted or the electrolyte membrane 11 is horizontal. Fuel used for the polymer electrolyte fuel cell is supplied to the fuel electrode 21 and the oxidant electrode 31. Here, the fuel supplied to the fuel electrode 21 includes, for example, liquid fuel such as methanol, ethanol, sodium borohydride aqueous solution, hydrogen, and the like. On the other hand, oxygen in the air is supplied to the oxidant electrode 31 as fuel. The fuel electrode part 2 is preferably provided with a fuel electrode outer wall 23 in order to block these fuels from the outside. The oxidant electrode 3 is supplied with oxygen in the air as a fuel used for power generation.

  FIG. 2 shows a cross-sectional view of the portion indicated by the dotted line in FIG. The side to which fuel is supplied (the right side in the figure) is the fuel electrode part 2 with the electrolyte membrane 11 as a boundary, and the side to which air is supplied (the left side in the figure) is the oxidant electrode part 3. A catalyst layer made of carbon on which a catalyst is supported is formed on both side surfaces of the electrolyte membrane 11. Examples of the catalyst include a catalyst supporting platinum particles, an alloy catalyst of ruthenium and selenium, and the like, but is not limited to this as long as it has catalytic activity for fuel. A gas diffusion layer (GDL) is obtained on the surface of the catalyst layer to obtain conductivity while ensuring the diffusibility of the fuel with respect to the catalyst layer. The gas diffusion layer is a porous conductive material, and the most frequently used example is carbon fiber. In addition, since the gas diffusion layer is porous, the conductivity as high as that of the bulk metal cannot be obtained, and the resistance loss is large when using the gas diffusion layer as an electrode. Therefore, a current collecting member made of a metal member such as gold, SUS, aluminum, nickel, or carbon is disposed on the surface of the gas diffusion layer, and collects current with a small resistance loss. Here, the catalyst layer, the GDL, and the current collecting member are collectively treated as the fuel cell electrode. The electrode to which fuel is supplied is the fuel electrode 21, and the electrode to which air is supplied is the oxidant electrode 31. Called.

  The fuel electrode 21 is provided with a fuel supply port 22 for supplying fuel, and fuel is supplied from a fuel source (not shown). Fuel sources include fuel tanks that store fuel such as liquid fuel and compressed hydrogen, hydrogen generators that obtain hydrogen by hydrolyzing hydrogen storage metals such as sodium borohydride and aluminum hydride, and methanol. And a reformer to obtain hydrogen.

  Since it is necessary to supply oxygen in the atmosphere, a space 32 is secured on the surface of the oxidant electrode 31, and a partition wall 33 is provided so as to face the oxidant electrode 31 with the space 32 as the center. In order to ensure the diffusibility of the air to the oxidizer electrode 31, it is desirable that the space 32 basically has no shield, but it is loaded with a fastening force in the stacking direction to maintain the shape of the power generation unit 1 and to obtain conductivity. In order to achieve this, a connecting portion 34 that connects the oxidant electrode 31 and the partition wall 33 may be provided.

  Further, the end portion which is the outer surface perpendicular to the oxidant electrode 31 is provided with an oxidant electrode outer wall 35 in order to prevent mechanical destruction due to mixing of substances from the outside of the power generation unit 1 and electrical short circuit. It is desirable that However, since it is necessary to supply oxygen in the air to the space 32 at the time of power generation, not all the oxidant electrode outer walls 35 are covered, but some communication between the air outside the power generation unit 1 and the space 32 Mouth is provided.

  Here, the operation of the present invention will be described. During power generation of the fuel cell, a reaction occurs in which protons and electrons are generated at the three-phase interface of the catalyst layer / fuel / electrolyte membrane 11 of the fuel electrode 21. Protons generated on the fuel electrode 21 side move through the electrolyte membrane 11 to the oxidant electrode 31, and electrons flow through the external circuit via the current collector and move to the oxidant electrode 31. Protons that have moved to the oxidant electrode 31 combine with oxygen in the air and electrons that have moved through the external circuit at the three-phase interface in the oxidant electrode 31 to generate water. Through the above process, the power generation unit 1 generates power with heat generation. The water generated at the oxidizer electrode 31 is evaporated by the heat generated during power generation and becomes water vapor and diffuses into the space 32. The air existing in the space 32 flows upward by heat convection due to heat generated during power generation.

  As shown in FIGS. 1 and 2, one or more communication ports are provided near the first end 361 existing above the power generation unit 1 and near the second end 362 existing below the power generation unit 1. Has been placed. Here, the communication port near the first end 361 is referred to as a first communication port 371, and the communication port close to the second end 362 is referred to as a second communication port 372. The air in the space 32 flows from below to above by heat convection. In this example, in order to save wasteful power consumption and increase the energy efficiency of the power generation system, forced air supply using a pump, a blower, or the like is not performed. Therefore, the air supply is mainly performed by the above-described thermal convection. That is, since air is supplied from the second communication port 372 and the cathode off gas used for power generation is exhausted from the first communication port 371, effective diffusibility can be obtained. Here, the positions of the first communication port 371 and the second communication port 372 are the center line 38 and the center of the first end 361 and the second end 362 is the first end 361 from the center line 38. And the second end 362 is more preferably at the end than at the center. That is, it is preferable that the first communication port 371 is in the uppermost region and the second communication port 372 is in the lowermost region when the power generation unit 1 is divided into four in the vertical direction. FIG. 3 shows a cross-sectional view of the surface indicated by the broken line in FIG. A region indicated by dots in the figure is a power generation region 311, and a catalyst layer is formed in this region. Further, the first communication port 371 and the second communication port 372 are concentrated in the above-described region. Thereby, the effect that air is supplied from the outside of the power generation unit 1 into the space 32 from the lower second communication port 372 and the air in the space 32 is discharged from the upper first communication port 371 is significantly obtained.

  Here, if the partition wall 33 is not provided, the water vapor in the space 32 not only moves upward but also moves in the vertical direction of the electrolyte membrane 31 so that the water vapor is very easily diffused. Therefore, when the power generation unit 1 is at a high temperature, the water vapor is excessively diffused and easily falls into a dry-up state. On the other hand, when the partition wall 33 is present, the diffusion of water vapor in the vertical direction of the electrolyte membrane 31 is prevented, so that the water vapor pressure in the space 32 is kept higher than when the partition wall 33 is present. In addition, since the air contains water vapor generated on the oxidant electrode 31 in the process of moving upward in the space 32, the upper portion of the space 32 is kept at a higher water vapor pressure. Since the air warmed by the heat radiation from the oxidant electrode 31 is moving upward from below, the air present above becomes higher in temperature. For this reason, the heat of the oxidant electrode 31 is difficult to dissipate upward, so that the temperature of the oxidant electrode 31 becomes high, and the evaporation of water vapor is remarkably easy to dry up. In other words, by providing the partition wall 33, water vapor can be supplied to the upper oxidant electrode 31 that is easy to dry up, so that dry up can be efficiently suppressed.

  Moreover, the outline of another example of arrangement | positioning of a communicating port is shown in FIG. 4, FIG. FIG. 4 shows an example in which the partition wall 33 is provided with a wide first communication port 371 (a) and a second communication port 372 (a). The first communication port 371 (a) and the second communication port 372 (a) can obtain the same effect even if they are provided not only on the wall surface perpendicular to the oxidizer electrode 31 but also on the partition wall 33. . In this example, the first communication port 371 (a) and the second communication port 372 (a) have the same width as the power generation region 311 of the oxidant electrode 31. For this reason, air is easily supplied and exhausted, and the air diffusibility is hardly inhibited by the provision of the partition wall 33. Furthermore, as shown in FIG. 5, the same effect can be obtained when both the wall surface and the partition wall 33 are provided with a plurality of first communication ports 371 (a), (b) and second communication ports 372 (a), (b). Is obtained.

  The present invention is effective not only when applied to a single layer cell but also to a stacked cell. When applied to the stacked cell, the fuel electrode outer wall 23 can be used as the partition wall 33. Even in the case of a single-layer cell, a unit other than the power generation unit 1 such as a control unit or a fuel source used for a fuel cell, or a part of equipment used using the power of the fuel cell may be used as the partition wall 33. .

That is, according to this embodiment, it is possible to efficiently suppress dry-up while ensuring sufficient air diffusibility during power generation.
[Second Embodiment]
A fuel cell according to a second embodiment of the present invention will be described based on FIG.

  FIG. 6 is a schematic diagram for explaining the outline of the fuel cell according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same member as the fuel cell of 1st Embodiment.

  As shown in FIG. 6, the hydration means 4 is provided near the second communication port 372 of the power generation unit 1. The hydration means 4 is a structure that sends water to the oxidant electrode 31. Examples of the hydration means 4 include an ejection device that hydrates by humidifying the oxidant electrode 31 by spraying, a liquid channel disposed up to the oxidant electrode 31 using capillary force, and the like. When the usage environment of the power generation unit 1 is known, the heat generated by the oxidizer electrode 31 and the evaporation amount of water vapor associated therewith can be obtained. Can be suppressed. Similarly, with respect to the liquid channel, dry-up can be effectively suppressed by setting the capillary force in accordance with the required amount of water during power generation.

That is, according to the present embodiment, in addition to the effects shown in the first embodiment, it is possible to further suppress dry-up.
[Third Embodiment]
A fuel cell according to a third embodiment of the present invention will be described based on FIG.

  FIG. 7 is a schematic diagram for explaining the outline of the fuel cell according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same member as the fuel cell of 1st Embodiment and 2nd Embodiment.

  As shown in FIG. 7, a storage means 42 is connected to the hydration means 4 via a water conduit 41. Water is stored in the storage means 42, and water is supplied to the hydration means 4 by passing through the water conduit 41. Therefore, continuous water evaporation is possible by supplying water from the storage means 42 in the hydration means 4. Here, the hydration unit 4 includes an evaporation unit 43 that evaporates water into water vapor and supplies water vapor to the second communication port 372. Since the second communication port 372 takes in nearby air, the water vapor evaporated in the evaporation unit 43 is also taken in together with the air. Here, since the hydration means 4 only needs to have a function for evaporating water, a plate material in which water exists or the storage means itself may be used. However, in order to evaporate more water vapor, the heating means 44 may be provided in the vicinity of the evaporation section 43. Examples of the heating means 44 include heat generation by a heater, reaction heat of a hydrogen generation reaction of a hydrogen generator, heat used for a reforming reaction of a reformer, heat generation of an electronic device using a fuel cell, and the like. Of course, the substance is not limited to the above as long as it is a substance to which heat energy for evaporating water is given. The evaporation unit 43 warmed by the heating means 44 becomes a high temperature, and more water that contacts the evaporation unit 43 can be evaporated.

That is, according to this embodiment, the suppression of dry-up can be continued for a long time.
[Fourth Embodiment]
A fourth embodiment according to the present invention will be described with reference to FIG.

  FIG. 8 is a schematic diagram for explaining the outline of the fuel cell according to the fourth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same member as the fuel cell of 1st Embodiment thru | or 3rd Embodiment.

  As shown in FIG. 8, a heat transfer body 441 is provided as the heating means 44, and the heat adding means 4 is provided with a heat insulating means 45. The heat transfer body 441 is connected to the oxidant electrode 31 and the evaporation unit 43, absorbs heat generated in the power generation reaction generated at the oxidant electrode 31, and transfers the heat to the evaporation unit 43. The heat transfer body 441 preferably has a structure covering the entire power generation region 311 shown in FIG. 3 in order to absorb heat generated at the oxidant electrode 31 more efficiently. Moreover, in order not to inhibit the air supply to the oxidant electrode 31, the porous body is preferable. As an example of a porous body, since metal members, such as a foam metal and a punching metal, have high thermal conductivity, it is preferable. In order to reduce the number of constituent members of the power generation unit 1, the heat transfer body 441 and the current collector member of the oxidizer electrode 31 may be the same. Thus, the heat transfer body 441 becomes a high temperature by absorbing heat generated during power generation at the oxidant electrode 31, and the heat of the heat transfer body 441 is transmitted to the evaporation section 43 to promote evaporation of water vapor in the evaporation section 43. Can do. Further, the heat insulating means 45 is provided at a place in contact with the atmosphere other than the evaporation section 43 of the water adding means 4. Therefore, the thermal energy transmitted to the hydration means 4 is effectively used only for the evaporation of water in the evaporation section 43. Examples of the heat insulating means 45 include a vacuum heat insulating layer formed of a plate material having a vacuum layer inside, a heat insulating sheet formed of a porous resin, and the like.

  Moreover, it is preferable that the surface of the evaporation part 43 has a raised shape. The raised shape may be a shape that can secure a wide effective area for evaporating water with respect to the apparent area of the evaporation portion 43. By having the above raised shape, the evaporating unit 43 can evaporate more water.

  FIG. 9 shows another specific example of the evaporation unit 43. FIG. 9 shows a structure in which the wall surface of the second communication port 372 provided in the oxidant electrode outer wall 35 is the evaporation portion 43. Further, in order to use the heat transfer body 441 shown in FIG. 8 as a current collecting member so that heat generated in the power generation region 311 shown in FIG. 3 can be efficiently absorbed, the heat transfer body 441 shown in FIG. 31 and is in a thermally connected state. Thus, the heat generated in the power generation unit 1 is given to the evaporation unit 43 through the heat transfer body 441 shown in FIG.

  A plurality of fins 431 are provided on the wall surface of the second communication port 372 serving as the evaporation unit 43 as a raised shape. Moreover, it is desirable that the evaporation unit 43 diffuses water on the surface so that water can be effectively evaporated on all surfaces. As a means for diffusing water, the surface of the evaporating part 43 is subjected to a hydrophilic treatment, water absorbing fibers are attached to the surface of the evaporating part 43, a fine groove is provided on the surface of the evaporating part 43, and water is transferred using a capillary force. Is mentioned. Not only the diffusing means but also any means capable of diffusing water over the entire evaporation unit 43 may be used.

That is, according to the present embodiment, in addition to the effects shown in the third embodiment, the energy used for water evaporation uses the heat generated during power generation, so there is no need to use extra energy to operate the hydration unit 4. , Dry-up can be suppressed with low power consumption.
[Fifth Embodiment]
A fifth embodiment according to the present invention will be described with reference to FIG.

  FIG. 10 is a schematic diagram for explaining the outline of the fuel cell according to the fifth embodiment of the present invention. The same members as those in the fuel cells of the first to fourth embodiments are denoted by the same reference numerals.

  As shown in FIG. 10, the power generation unit 1 includes a detection unit 5, and a value obtained by the detection unit 5 is input to the control unit 6 through a signal line indicated by a broken line. Connected by signal lines shown.

  The detection unit 5 has a function of detecting the temperature of the power generation unit 1 and may be located anywhere as long as the temperature of the power generation unit 1 can be measured. It is most desirable to measure the temperature of the oxidant electrode 31 because the oxidant electrode 31 closest to the power generation part causes a dry-up phenomenon depending on the temperature condition.

  Thus, the temperature of the power generation unit 1 obtained by the detection unit 5 is input to the control unit 6 through a signal line. The controller 6 that has read the temperature controls the water vapor to evaporate the water vapor when the temperature exceeds a certain value. When the outside temperature is 25 ° C., the power generation characteristics of the power generation unit 1 are greatly reduced due to the dry-up phenomenon when the temperature is higher than 70 ° C. Therefore, when the temperature obtained by the detection unit 5 is 70 ° C. or more, It is good to evaporate water vapor.

  Examples of means for controlling the evaporation of water vapor include the following. The control unit 6 is connected to the heating means 44, and when it is necessary to evaporate water vapor, it activates the heating means 44 to promote evaporation, and when it is not necessary to evaporate water vapor, it stops the heating means 44. As described above, there is a method of controlling the evaporation amount of water vapor by properly using the heating means 44 during operation and when it is stopped. As another method, the water conduit 41 is provided with a valve, and the control unit 6 is connected to the valve. When the water vapor needs to be evaporated, the valve is opened to supply water to the evaporation unit 43. Deliver liquid. When it is not necessary to evaporate the water vapor, the valve is closed and the liquid supply to the evaporating unit 43 is stopped to stop the evaporation of the water vapor in the evaporating unit 43. There is also a method for controlling the evaporation amount of water vapor by controlling the liquid feed to the evaporation unit 43 in this way. Moreover, when the electric power generation part 1 is the heat exchanger 441 like 4th Embodiment, the example which has the switching means which switches a heat insulation structure and a heat transfer structure in the process to the evaporation part 43 of the heat exchanger 441 is given. . As an example of the switching means, when the steam is necessary, the heat transfer body 441 is thermally connected. When the steam is not required, a part of the heat transfer body 441 is separated so that the thermal insulation is achieved. There is a means to put it in a state.

  That is, according to the present embodiment, it is possible to effectively suppress the dry-up of the second to fourth embodiments with a small amount of water and heat energy.

DESCRIPTION OF SYMBOLS 1 Electric power generation part 2 Fuel electrode part 3 Oxidant electrode part 4 Hydration means 5 Detection part 6 Control part 11 Electrolyte membrane 21 Fuel electrode 22 Fuel supply port 23 Fuel electrode outer wall 31 Oxidant electrode 32 Space 33 Partition 34 Connection part 35 Oxidant electrode Outer wall 361 First end 362 Second end 38 Center line 41 Water conduit 42 Reserving means 43 Evaporating part 44 Heating means 45 Heat insulating means 371 First communication port 372 Second communication port 431 Fin

Claims (8)

A power generation unit composed of a fuel electrode, an oxidant electrode, an electrolyte membrane sandwiched between the fuel electrode and the oxidant electrode, and a communication port communicating with the atmosphere, and air in the atmosphere via the communication port Is a fuel cell that is supplied by natural intake to the oxidant electrode as an oxidant,
An oxidant electrode having the oxidant electrode, a partition wall provided to face the surface of the oxidant electrode on which the electrolyte membrane is disposed, and a space formed by the oxidant electrode and the partition wall. Part
The oxidant electrode side portion includes a first end portion and a second end portion opposite to the first end portion,
The first end is provided at a position higher than the second end,
At least one first communication port located near the first end from the center of the first end and the second end; and
At least one second communication port located near the second end from the center of the first end and the second end; and
A fuel cell comprising:   The fuel cell according to claim 1, further comprising a hydration unit that supplies water to the oxidant electrode at a side of the second end.   The fuel cell according to claim 2, wherein the hydration unit includes an evaporation unit that evaporates water supplied from a water storage unit.   4. The fuel cell according to claim 3, wherein the hydrating unit includes a heating unit, and the evaporation unit is heated by the heating unit.   The fuel cell according to claim 4, wherein the heating unit is a heat transfer body that transfers heat generated in the power generation unit during power generation to the evaporation unit.   The fuel cell according to any one of claims 3 to 5, wherein the hydrating means has a heat insulating means on a surface in contact with the atmosphere other than the evaporation section.   The fuel cell according to any one of claims 3 to 6, wherein the evaporation portion is a surface having one or more raised shapes on the surface.   A detection unit that detects the temperature of the power generation unit, and a control unit that controls a hydration unit to evaporate the water in the evaporation unit when a detection value obtained by the detection unit is a predetermined value or more. The fuel cell according to any one of claims 3 to 7, characterized in that:

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