JP2007311032A - Fuel cartridge for fuel cell and fuel cell using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve safety and reliability by suppressing remaining of a liquid fuel at the tip of a nozzle in a fuel cartridge supplying a liquid fuel to a fuel cell. <P>SOLUTION: The fuel cartridge for the fuel cell 5 is provided with a cartridge main body 8 to house the liquid fuel for fuel cell and a nozzle 9 to supply the liquid fuel to the fuel cell main body 4. The nozzle 9 is provided with a nozzle head 12 installed on the cartridge main body 8 and a valve 16 or the like arranged in the nozzle head 12. A liquid fuel passage in the nozzle 9 is sealed at a plurality of locations based on a main seal portion based on the function of valve origin and a sub seal portion constructed by combining a valve stem 16b and an inner wall face 14a or the like of the insertion portion 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cartridge for a fuel cell and a fuel cell using the same.

  In recent years, attempts have been made to use a fuel cell as a power source for portable electronic devices such as notebook computers and mobile phones so that they can be used for a long time without being charged. A fuel cell has a feature that it can generate electric power only by supplying fuel and air, and can generate electric power continuously for a long time by replenishing only fuel. For this reason, if the fuel cell can be reduced in size, it can be said that the system is extremely advantageous as a power source for portable electronic devices.

  In particular, a direct methanol fuel cell (DMFC) using methanol fuel with a high energy density can be downsized and the fuel can be easily handled, so it is promising as a power source for portable devices. Has been. As the liquid fuel supply method in the DMFC, there are known an active method such as a gas supply type and a liquid supply type, and a passive method such as an internal vaporization type in which the liquid fuel in the fuel container is vaporized inside the cell and supplied to the fuel electrode. It has been. Of these, the passive method is advantageous for downsizing the DMFC.

  In a passive type DMFC such as an internal vaporization type, the liquid fuel in the fuel storage section is vaporized through, for example, a fuel impregnation layer or a fuel vaporization layer, and the vaporized component of this liquid fuel is supplied to the fuel electrode (for example, patents). References 1-2). Further, liquid fuel is supplied to the fuel storage portion using a fuel cartridge. In satellite type (external injection type) fuel cartridges, attempts have been made to shut off and inject liquid fuel using a coupler composed of a nozzle part and a socket part each incorporating a valve mechanism (for example, (See Patent Document 3).

In supplying (injecting) liquid fuel from a satellite type (external injection type) fuel cartridge into the fuel storage portion of the DMFC, it is important to prevent leakage of the liquid fuel from the viewpoint of safety and the like. The fuel cartridge and the fuel storage part of the DMFC can shut off the liquid fuel by a coupler (nozzle part and socket part) incorporating the valve mechanism as described above. Further, when the fuel cartridge and the fuel storage portion are connected, a mechanism for sealing the connection portion between the nozzle portion and the socket portion is applied to prevent the liquid fuel from leaking.
Japanese Patent No. 3413111 JP 2004-171844 A Japanese Patent Laid-Open No. 2004-127824

  As described above, although a mechanism for preventing leakage of liquid fuel is applied to each part of the fuel cartridge and the fuel storage part, when the fuel cartridge after supplying the liquid fuel is removed from the fuel storage part In some cases, methanol fuel or the like adheres to the tip of the nozzle portion of the fuel cartridge in a liquid state. Even such a small amount of liquid fuel is required not to remain at the tip of the nozzle portion in order to improve safety and the like.

  The present invention has been made to cope with such a problem. A fuel cartridge for a fuel cell, which is improved in safety and reliability by suppressing liquid fuel remaining at the tip of a nozzle portion, and such a fuel cartridge. It aims at providing the fuel cell using this.

  A fuel cartridge for a fuel cell according to an aspect of the present invention includes a cartridge main body that stores liquid fuel for a fuel cell, a nozzle head that is mounted on the cartridge main body, and a valve mechanism that is disposed in the nozzle head. In the fuel cartridge for a fuel cell, the liquid fuel flow path in the nozzle portion is sealed at a plurality of locations.

  A fuel cell according to another aspect of the present invention includes a fuel cartridge according to the above-described aspect of the present invention, a fuel storage portion having a socket portion detachably connected to a nozzle portion of the fuel cartridge, and the fuel storage portion. And a fuel cell main body including an electromotive unit that is supplied with the liquid fuel and performs a power generation operation.

  Since the fuel cartridge for a fuel cell according to the aspect of the present invention seals the liquid fuel flow path in the nozzle portion at a plurality of locations, the liquid fuel can be prevented from remaining at the tip of the nozzle portion after the fuel cartridge is pulled out. it can. According to such a fuel cell fuel cartridge and a fuel cell using the same, safety and reliability can be improved.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, although embodiment of this invention is described based on drawing below, those drawings are provided for illustration and this invention is not limited to those drawings.

  FIG. 1 is a diagram showing a configuration of a fuel cell according to a first embodiment of the present invention. A fuel cell 1 shown in FIG. 1 includes a fuel cell body 4 mainly composed of a fuel cell 2 serving as an electromotive unit and a fuel storage unit 3, and a satellite type (external injection) for supplying liquid fuel to the fuel storage unit 3. And a fuel cartridge 5 of the formula). A fuel supply section 7 having a socket section 6 serving as a liquid fuel supply port is provided on the lower surface side of the fuel storage section 3. As will be described in detail later, the socket portion 6 incorporates a valve mechanism, and is closed except when liquid fuel is supplied.

  On the other hand, the fuel cartridge 5 has a cartridge body (container) 8 that stores liquid fuel for a fuel cell. At the tip of the cartridge body 8, there is provided a nozzle portion 9 that serves as a fuel outlet when supplying liquid fuel accommodated in the cartridge body 8 to the fuel cell body 4. As will be described in detail later, the nozzle portion 9 has a built-in valve mechanism and is closed except when liquid fuel is supplied. Such a fuel cartridge 5 is connected to the fuel cell main body 4 only when, for example, liquid fuel is injected into the fuel storage portion 3.

  The cartridge main body 8 of the fuel cartridge 5 contains liquid fuel corresponding to the fuel cell main body 4, for example, methanol fuel such as methanol aqueous solutions of various concentrations or pure methanol in the case of a direct methanol fuel cell (DMFC). The liquid fuel stored in the cartridge body 8 is not necessarily limited to methanol fuel, and may be ethanol fuel such as ethanol aqueous solution or pure ethanol, dimethyl ether, formic acid, or other liquid fuel. In any case, liquid fuel corresponding to the fuel cell main body 4 is accommodated.

  The socket portion 6 provided in the fuel storage portion 3 of the fuel cell main body 4 and the nozzle portion 9 provided in the cartridge main body 8 of the fuel cartridge 5 constitute a pair of connection mechanisms (couplers). A specific configuration of the coupler including the socket portion 6 and the nozzle portion 9 will be described with reference to FIGS. 2 and 3. FIG. 2 shows a state before the nozzle part 9 of the fuel cartridge 5 is connected to the socket part 6 of the fuel cell main body 4, and FIG. 3 shows a state after the nozzle part 9 and the socket part 6 are connected.

  In the coupler for connecting the fuel cell main body 4 and the fuel cartridge 5, a nozzle part (male side coupler) 9 as a cartridge side connection mechanism has a nozzle head 12 having a nozzle port 11 opened on the tip side. The nozzle head 12 has a base portion 13 that is attached to the front end opening of the cartridge body 8 and an insertion portion 14 that is inserted into the socket portion 6. The cylindrical insertion portion 14 is formed so as to protrude from the base portion 13 so that its axial direction is parallel to the insertion direction of the nozzle portion 9. The inner wall surface 14a of the insertion portion 14 constitutes a secondary seal portion as will be described in detail later. For example, the inner wall surface 14a has a tapered shape with a diameter reduced toward the distal end of the insertion portion 14.

  A cup-shaped valve holder 15 is disposed inside the base portion 13 of the nozzle head 12. The valve holder 15 defines a valve chamber, and the outer edge portion on the front end side is sandwiched between the cartridge body 8 and the base portion 13. A valve 16 is disposed in the valve holder 15. The valve 16 includes a valve head 16a, a valve stem 16b, and a guide pin 16c. Furthermore, communication holes 15 a and 15 b are provided at the bottom of the valve holder 15, and a guide pin 16 c provided on the rear side of the valve 16 is inserted into the communication hole 15 a. The liquid fuel in the cartridge body 8 flows out into the nozzle portion 9 through the communication holes 15a and 15b.

  The valve head 16 a is disposed in the valve chamber defined by the valve holder 15. The valve stem 16 b is accommodated in the cylindrical insertion portion 14. As shown in FIG. 4, a ring-shaped protrusion (rib) 17 that forms a sub-seal portion in combination with the tapered inner wall surface 14 a of the insertion portion 14 is provided at the distal end portion of the valve stem 16 b. That is, the ring-shaped protrusion 17 is provided along the circumferential direction on the outer peripheral surface of the valve stem 16b so as to contact the tapered inner wall surface 14a to form a secondary seal portion. The ring-shaped protrusion 17 is not limited to one place, and may be provided at a plurality of places on the outer peripheral surface of the valve stem 16b as will be described later. In this case, the ring-shaped protrusion 17 is preferably provided at least at the tip of the valve stem 16b.

  The valve 16 having the valve head 16a and the valve stem 16b as described above can be advanced and retracted in the axial direction (insertion direction of the nozzle portion 9). An O-ring 19 is disposed between the valve head 16 a and the valve seat 18 formed inside the base portion 13. A pressing force is applied to the valve 16 toward the distal end by an elastic member such as a compression spring 20, whereby the O-ring 19 is pressed against the valve seat 18. The valve head 16a, the valve seat 18, the O-ring 19 and the like constitute a main seal portion that blocks the liquid fuel flow path in the nozzle portion 12.

  In a normal state (a state in which the fuel cartridge 5 is separated from the fuel cell body 4), the spring force of the compression spring 20 is applied to the valve head 16a as a pressing force in the distal direction, whereby the O-ring 19 is It is pressed against the sheet 18. Accordingly, the main seal portion by the valve head 16a, the valve seat 18 and the like is in a closed state. In addition, since the pressing force in the distal direction by the compression spring 20 is also applied to the valve stem 16b, the ring-shaped protrusion 17 provided at the distal end of the valve stem 16b is connected to the tapered inner wall surface 14a of the insertion portion 14. It is pressed against. Therefore, the sub seal portion formed by the tapered inner wall surface 14a of the insertion portion 14 and the ring-shaped protrusion 17 is also closed.

  In the normal state, the liquid fuel flow path in the nozzle portion 9 is sealed at a plurality of locations by closing the main seal portion and the sub seal portion. On the other hand, when the fuel cartridge 5 is connected to the fuel cell body 4 as will be described later, the valve stem 16b is retracted to open the sub seal portion, and at the same time, the valve head 16a is moved to the valve as the valve stem 16b is retracted. The main seal portion is also opened by moving away from the seat 18. Thus, when the fuel cartridge 5 is connected to the fuel cell main body 4, the liquid fuel flow path in the nozzle portion 9 is established by opening the main seal portion and the sub seal portion, respectively.

  As shown in FIG. 4, the ring-shaped protrusions 17 constituting the sub-seal portion are not limited to one point on the tip of the valve stem 16b, but may be provided at a plurality of points on the outer peripheral surface of the valve stem 16b as shown in FIG. Good. Thereby, the sealing performance by the sub seal portion can be enhanced. The ring-shaped protrusion 17 is preferably provided at least at the tip of the valve stem 16b. Furthermore, as shown in FIGS. 6 and 7, it is also effective to arrange an elastic member 21 such as a rubber member along the tapered inner wall surface 14 a of the insertion portion 14 that contacts the ring-shaped protrusion 17. Thereby, the sealing performance by the sub seal portion can be further enhanced.

  The portion constituting the secondary seal portion in contact with the tapered inner wall surface 14a of the insertion portion 14 is not limited to the ring-shaped protrusion 17 such as the rib described above, but is a ring shape such as an O-ring as shown in FIG. The elastic member 22 may be used. That is, the nozzle portion 9 shown in FIG. 8 is provided with a ring-shaped elastic member 22 such as an O-ring at the tip of the valve stem 16b, and the ring-shaped elastic member 22 and the tapered inner wall surface 14a constitute a secondary seal portion. Has been. The ring-shaped elastic member 22 may be provided at a plurality of locations. Further, as shown in FIG. 9, the secondary seal portion may be constituted by the elastic member 21 arranged along the tapered inner wall surface 14 a of the insertion portion 14 and the tip end portion of the normal substantially cylindrical valve stem 16 b. Is possible.

  The sub-seal portion shown in FIGS. 4 to 9 basically constitutes a line seal. The sub-seal portion is not limited to these, and a face seal-like sub-seal portion can be applied as shown in FIG. FIG. 10 shows a secondary seal portion constituted by the tapered inner wall surface 14a of the insertion portion 14 and the tapered outer peripheral surface 16aA of the valve stem 16b. That is, the outer peripheral surface 16bA of the valve stem 16b has a tapered shape that is reduced in diameter toward the tip, and the tapered outer peripheral surface 16bA is brought into surface contact with the tapered inner wall surface 14a of the insertion portion 14 to thereby make a sub seal portion. Is configured.

  As described above, the sub seal portion only needs to be able to seal the liquid fuel flow path from the nozzle port 11 of the nozzle portion 12 to the main seal portion. As long as such a configuration is satisfied, sub seal portions having various configurations and shapes can be applied. Furthermore, the sub seal portion is not limited to one place, and may seal a plurality of places. In any case, the nozzle portion 9 of this embodiment has a liquid fuel flow path inside thereof by a main seal portion based on the original function of the valve 16 and a sub seal portion based on the secondary function of the valve 16. It is comprised so that it can interrupt | block at several places.

  As shown in FIG. 11, the insertion portion 14 of the nozzle head 12 has a key portion 23 provided on the base side thereof. This key portion 23 enables connection between the nozzle portion 9 and the socket portion 6 only when engaged with a key groove on the socket portion 6 side, which will be described later, and functions as an identification means for the fuel cartridge 5. It is. Further, the insertion portion 14 of the nozzle head 12 is provided with four claw portions 24. These claw portions 24 are engaged with the concave portions on the socket portion 6 side to hold the connection state between the nozzle portion 9 and the socket portion 6.

  On the other hand, the socket part (female side coupler) 6 as the fuel cell side connection mechanism has a cylindrical socket body 32 having a socket port 31 opened as shown in FIG. The socket main body 32 has a main body upper part 32 a, a main body middle part 32 b and a main body lower part 32 c, which are integrated and embedded in the fuel supply part 7 of the fuel cell main body 4. A rubber holder 33 is installed as an elastic holder on the middle part 32 b of the socket body 32. The rubber holder 33 is given elasticity in the axial direction based on its shape (bellows shape) and material properties (rubber elasticity). The rubber holder 33 is a seal member that forms a seal with the insertion portion 14 of the nozzle head 12, and the inside thereof is a liquid fuel flow path.

  A valve 34 is disposed in the socket body 32. The valve 34 includes a valve head 34a, a valve stem 34b, and a guide pin 34c. The valve head 34a is disposed in a valve chamber defined by the main body middle portion 32b and the main body lower portion 32c. The valve stem 34 b is accommodated in the rubber holder 33. Such a valve 34 can be moved back and forth in the axial direction (insertion direction of the nozzle portion 9). An O-ring 36 is disposed between the valve head 34a and the valve seat 35 formed on the lower surface side of the main body middle portion 32b.

  A force for pressing the valve head 34a against the valve seat 25 by an elastic member such as a compression spring 37 is constantly applied to the valve 34, whereby the O-ring 36 is pressed. In a normal state (a state in which the fuel cartridge 5 is separated from the fuel cell main body 4), the O-ring 36 is pressed against the valve seat 35 via the valve head 34a, whereby the liquid fuel flow path in the socket portion 6 is obtained. Is closed. When the fuel cartridge 5 is connected to the fuel cell body 4, the valve stem 34 b is retracted and the valve head 34 a is separated from the valve seat 35, whereby the fuel flow path in the socket portion 6 is opened.

  Communication holes 38 a and 38 b are provided in the main body lower portion 32 c of the socket main body 32, and these communication holes 38 a and 38 b are connected to the fuel storage portion 3 through the communication holes 7 a of the fuel supply portion 7. A guide pin 34c provided on the rear side of the valve 34 is inserted into the communication hole 38a. Thus, the socket part 6 is connected to the fuel accommodating part 3 through the communication holes 38a and 38b provided in the lower part 32c of the liquid fuel flow path in the socket body 32. Then, the liquid fuel stored in the fuel cartridge 5 is stored in the fuel via the nozzle 9 and the socket 6 by opening the liquid fuel flow paths in the nozzle 9 and the socket 6 with the valves 16 and 34 opened. It is possible to inject into the part 3.

  Further, as shown in FIG. 12, the socket main body 32 is provided with a key groove 39 that engages with the key portion 23 of the nozzle portion 9. Since the key portion 23 and the key groove 39 form a pair of shapes, for example, by defining the shape according to the liquid fuel, it is possible to prevent liquid fuel from being erroneously injected. That is, by making the shape of the key portion 23 and the key groove 39 in accordance with the specific liquid fuel, and enabling the nozzle portion 9 to be inserted into the socket portion 6 only when they are engaged, the fuel Only the liquid fuel corresponding to the battery body 4 can be supplied. The socket body 32 has a recess 40 that engages with the claw portion 24 of the nozzle portion 9.

  In supplying the liquid fuel accommodated in the fuel cartridge 5 to the fuel accommodating portion 3 of the fuel cell main body 4, the nozzle portion 9 of the fuel cartridge 5 is inserted into the socket portion 6 and connected. At that time, the nozzle portion 9 can be inserted into the socket portion 6 only when the shapes of the key portion 23 and the key groove 39 correspond to each other. When the nozzle portion 9 is inserted into the socket portion 6 in this manner, the tip of the insertion portion 14 of the nozzle head 12 and the tip of the rubber holder 33 first come into contact with each other, and the flow path of the liquid fuel before the valves 16 and 34 are opened. A peripheral seal is established.

  When the nozzle portion 9 is inserted into the socket portion 6 from the state in which the distal end of the insertion portion 14 of the nozzle head 12 and the rubber holder 33 are in contact with each other, the distal ends of the valve stem 16b of the nozzle portion 9 and the valve stem 34b of the socket portion 6 abut each other. When the nozzle portion 9 is further inserted into the socket portion 6 from this state, the valve 34 of the socket portion 6 moves backward to completely open the flow path, and then the valve 16 of the nozzle portion 9 moves backward to establish the liquid fuel flow path. Is done. As described above, the liquid fuel flow path on the nozzle portion 9 side is established by opening the main seal portion and the sub seal portion, respectively.

  Further, simultaneously with the establishment of the liquid fuel flow path in the nozzle part 9 and the socket part 6 described above, the claw part 24 of the nozzle part 9 engages with the concave part 40 of the socket part 6. Thereby, the connection state of the nozzle part 9 and the socket part 6 is established. As described above, the nozzle portion 9 and the socket portion 6 are connected to each other, and the liquid fuel seal portion by the valve mechanism incorporated therein is opened to open the liquid fuel flow path, thereby being accommodated in the fuel cartridge 5. The liquid fuel is supplied to the fuel storage part 3 of the fuel cell body 4.

  After the supply of the liquid fuel is completed, the fuel cartridge 5 is pulled out from the fuel storage portion 3 to release the connection between the nozzle portion 9 and the socket portion 6. At this time, the main seal portion based on the original function of the valve 16 of the nozzle portion 9 returns to the closed state when the connection state with the socket portion 6 is released, so that liquid fuel does not leak from the fuel cartridge 5. Absent. Further, at the same time as the main seal portion is shut off, the sub seal portion constituted by, for example, the valve stem 16b and the inner wall surface (for example, tapered inner wall surface) 14a of the insertion portion 14 is also shut off. Since the sub seal part is provided on the tip side of the nozzle part 9 from the main seal part, the liquid fuel remaining in the flow path between the main seal part and the tip of the nozzle part 9 is also blocked by the sub seal part. Can do.

  If only the liquid fuel is shut off based on the main function of the valve 16 of the nozzle part 9, there may be a case where a small amount of liquid fuel adhering to the surface of the valve stem 16b remains on the tip side of the nozzle part 9 (tip of the insertion part 14). is there. Even with such a small amount of liquid fuel, it is important not to touch the operator in order to improve safety and the like. Liquid fuel remaining on the surface of the valve stem 16b and the like can be prevented from leaking to the outside by closing the sub seal portion. In particular, the liquid fuel remaining on the front end side of the nozzle portion 9 can be greatly reduced by configuring the sub seal portion at the front end portion of the valve stem 16b. Therefore, the safety and reliability of the fuel cartridge 5 and the fuel cell 1 using the fuel cartridge 5 can be greatly increased.

  Next, a specific structure of the fuel cell body 4 in the fuel cell 1 of the above-described embodiment will be described. The fuel cell body 4 is not particularly limited, and for example, a passive or active DMFC to which a satellite type fuel cartridge 5 is connected when necessary can be applied. Here, an embodiment in which an internal vaporization type DMFC is applied to the fuel cell main body 4 will be described with reference to FIG. The internal vaporization type (passive type) DMFC 4 shown in FIG. 13 includes a gas selective permeable membrane 51 interposed between the fuel cell 2 and the fuel storage unit 3 constituting the electromotive unit. Yes.

  The fuel cell 2 includes an anode (fuel electrode) composed of an anode catalyst layer 52 and an anode gas diffusion layer 53, a cathode (oxidant electrode / air electrode) composed of a cathode catalyst layer 54 and a cathode gas diffusion layer 55, and an anode catalyst. A membrane electrode assembly (MEA) composed of a proton (hydrogen ion) conductive electrolyte membrane 56 sandwiched between the layer 52 and the cathode catalyst layer 54 is provided. Examples of the catalyst contained in the anode catalyst layer 52 and the cathode catalyst layer 54 include a simple substance of a platinum group element such as Pt, Ru, Rh, Ir, Os, and Pd, an alloy containing the platinum group element, and the like.

  Specifically, it is preferable to use Pt—Ru, Pt—Mo or the like having strong resistance to methanol or carbon monoxide for the anode catalyst layer 52, and Pt, Pt—Ni or the like for the cathode catalyst layer 54. Further, a supported catalyst using a conductive support such as a carbon material or an unsupported catalyst may be used. Examples of the proton conductive material constituting the electrolyte membrane 56 include fluorine-based resins such as perfluorosulfonic acid polymer having a sulfonic acid group (Nafion (trade name, manufactured by DuPont) and Flemion (trade name, manufactured by Asahi Glass Co., Ltd.). Etc.), hydrocarbon resins having a sulfonic acid group, and inorganic substances such as tungstic acid and phosphotungstic acid. However, it is not restricted to these.

  The anode gas diffusion layer 53 laminated on the anode catalyst layer 52 serves to uniformly supply fuel to the anode catalyst layer 52 and also serves as a current collector for the anode catalyst layer 52. On the other hand, the cathode gas diffusion layer 55 laminated on the cathode catalyst layer 54 serves to uniformly supply the oxidant to the cathode catalyst layer 54 and also serves as a current collector for the cathode catalyst layer 54. An anode conductive layer 57 is stacked on the anode gas diffusion layer 53, and a cathode conductive layer 58 is stacked on the cathode gas diffusion layer 55.

  The anode conductive layer 57 and the cathode conductive layer 58 are configured by a mesh, a porous film, a thin film, or the like made of a conductive metal material such as gold. Rubber O-rings 59 and 60 are interposed between the electrolyte membrane 56 and the anode conductive layer 57, and between the electrolyte membrane 56 and the cathode conductive layer 58, and thereby, fuel cell (membrane). Electrode assembly) 2 prevents fuel leakage and oxidant leakage.

  The fuel storage unit 3 is filled with methanol fuel as the liquid fuel F. Further, the fuel storage unit 3 is opened on the fuel cell 2 side, and a gas selective permeable membrane 51 is installed between the opening of the fuel storage unit 3 and the fuel cell 2. The gas selective permeable membrane 51 is a gas-liquid separation membrane that transmits only the vaporized component of the liquid fuel F and does not transmit the liquid component. Examples of the constituent material of the gas selective permeable membrane 51 include a fluororesin such as polytetrafluoroethylene. Here, the vaporization component of the liquid fuel F is a mixture of a vaporization component of methanol and a vaporization component of water when a methanol aqueous solution is used as the liquid fuel F, and a vaporization component of methanol when pure methanol is used. Means.

  A moisturizing layer 61 is laminated on the cathode conductive layer 58, and a surface layer 62 is further laminated thereon. The surface layer 62 has a function of adjusting the amount of air that is an oxidant, and the adjustment is performed by changing the number and size of the air inlets 63 formed in the surface layer 62. The moisturizing layer 61 is impregnated with a part of the water produced in the cathode catalyst layer 54 and serves to suppress the transpiration of water, and by uniformly introducing an oxidant into the cathode gas diffusion layer 55, the cathode catalyst. It also has the function of promoting uniform diffusion of the oxidant into the layer 54. The moisturizing layer 61 is composed of, for example, a porous member, and specific constituent materials include polyethylene and polypropylene porous bodies.

  Then, the gas permselective membrane 51, the fuel cell 2, the moisture retention layer 61, and the surface layer 62 are laminated in this order on the fuel storage unit 3, and further covered with, for example, a stainless steel cover 64 to hold the whole. The internal vaporization type DMFC (fuel cell main body) 4 of this embodiment is configured. The cover 64 is provided with an opening at a portion corresponding to the air inlet 63 formed in the surface layer 62. Further, the fuel storage unit 3 is provided with a terrace 65 for receiving the claw 64 a of the cover 64, and the entire fuel cell body 4 is integrally held by the cover 64 by caulking the claw 64 a to the terrace 65. . Although not shown in FIG. 13, as shown in FIG. 1, a fuel supply unit 7 having a socket unit 6 is provided on the lower surface side of the fuel storage unit 3.

In the internal vaporization type DMFC (fuel cell main body) 4 having the above-described configuration, the liquid fuel F (for example, methanol aqueous solution) in the fuel storage unit 3 is vaporized, and this vaporized component permeates the gas selective permeable membrane 51. Then, the fuel cell 2 is supplied. In the fuel cell 2, the vaporized component of the liquid fuel F is diffused in the anode gas diffusion layer 53 and supplied to the anode catalyst layer 52. The vaporized component supplied to the anode catalyst layer 52 causes an internal reforming reaction of methanol represented by the following formula (1).
CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ (1)

  In addition, when pure methanol is used as the liquid fuel F, water vapor is not supplied from the fuel storage unit 3, so water generated in the cathode catalyst layer 54 or water in the electrolyte membrane 56 is reacted with methanol (1) The internal reforming reaction is caused to occur, or the internal reforming reaction is caused by another reaction mechanism that does not require water, regardless of the internal reforming reaction of the above formula (1).

Protons (H ⁺ ) generated by the internal reforming reaction are conducted through the electrolyte membrane 56 and reach the cathode catalyst layer 54. Air (oxidant) taken from the air inlet 63 of the surface layer 62 diffuses through the moisture retaining layer 61, the cathode conductive layer 58, and the cathode gas diffusion layer 55 and is supplied to the cathode catalyst layer 54. The air supplied to the cathode catalyst layer 54 causes the reaction shown in the following formula (2). This reaction causes a power generation reaction that accompanies the generation of water.
(3/2) O ₂ + 6H ⁺ + 6e ⁻ → 3H ₂ O (2)

  As the power generation reaction based on the above-described reaction proceeds, the liquid fuel F (for example, methanol aqueous solution or pure methanol) in the fuel storage unit 3 is consumed. Since the power generation reaction stops when the liquid fuel F in the fuel storage unit 3 becomes empty, the liquid fuel is supplied from the fuel cartridge 5 into the fuel storage unit 3 at that time or before that time. As described above, the liquid fuel is supplied from the fuel cartridge 5 by inserting and connecting the nozzle portion 9 on the fuel cartridge 5 side to the socket portion 6 on the fuel cell body 4 side.

  Note that the present invention is not limited to the method and mechanism as long as it is a fuel cell that supplies liquid fuel by a fuel cartridge, but it is particularly a passive DMFC such as an internal vaporization type that is being miniaturized. It is suitable for.

It is a figure which shows the structure of the fuel cell by one Embodiment of this invention. FIG. 2 is a cross-sectional view showing the configuration (unconnected state) of a nozzle part on the fuel cartridge side and a socket part on the fuel cell body side in the fuel cell shown in FIG. 1. It is sectional drawing which shows the connection state of the nozzle part and socket part which are shown in FIG. It is sectional drawing which shows the structure of the nozzle part shown in FIG. It is sectional drawing which shows the modification of the nozzle part shown in FIG. It is sectional drawing which shows the other modification of the nozzle part shown in FIG. It is sectional drawing which shows the modification of the nozzle part shown in FIG. It is sectional drawing which shows the further another modification of the nozzle part shown in FIG. It is sectional drawing which shows the further another modification of the nozzle part shown in FIG. It is sectional drawing which shows the further another modification of the nozzle part shown in FIG. It is a top view which shows the structure of the insertion part in the nozzle part shown in FIG. It is a top view which shows the structure of the socket main body in the socket part shown in FIG. It is sectional drawing which shows the structure of internal vaporization type DMFC as an example of the fuel cell main body in the fuel cell of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell, 2 ... Fuel cell, 3 ... Fuel accommodating part, 4 ... Fuel cell main body, 5 ... Fuel cartridge, 6 ... Socket part (female side coupler), 8 ... Cartridge main body, 9 ... Nozzle part (male side) 11) Nozzle port, 12 ... Nozzle head, 14 ... Insertion part, 15 ... Valve holder, 16, 34 ... Valve, 16a, 34a ... Valve head, 16b, 34b ... Valve stem, 17 ... Ring-shaped projection, 18, 35 ... Valve seat, 19, 36 ... O-ring, 20, 37 ... Compression spring, 21 ... Elastic member, 22 ... Ring-like elastic member, 33 ... Rubber holder, 51 ... Gas selective permeable membrane.

Claims (12)

In a fuel cartridge for a fuel cell, comprising: a cartridge main body that contains a liquid fuel for a fuel cell; and a nozzle portion that has a nozzle head mounted on the cartridge main body and a valve mechanism disposed in the nozzle head.
The fuel cartridge for a fuel cell, wherein the flow path of the liquid fuel in the nozzle portion is sealed at a plurality of locations. The fuel cartridge for a fuel cell according to claim 1, wherein
The valve mechanism includes a main seal portion including a valve having a valve head and a valve stem, an elastic member that presses the valve head against a valve seat provided in the nozzle head, the valve stem, and the nozzle. A fuel cartridge for a fuel cell, comprising: a sub-seal portion configured with an inner wall surface of the head. The fuel cartridge for a fuel cell according to claim 2,
The sub-seal portion is provided along the circumferential direction on the outer peripheral surface of the valve stem, the tapered inner wall surface having a diameter reduced toward the tip of the nozzle head, and in contact with the tapered inner wall surface. A fuel cartridge for a fuel cell, comprising a ring-shaped protrusion for sealing the liquid fuel flow path. The fuel cartridge for a fuel cell according to claim 3,
The fuel cartridge for a fuel cell, wherein the ring-shaped protrusion is provided at least at a tip of the valve stem. The fuel cartridge for a fuel cell according to claim 3 or 4,
The fuel cartridge for a fuel cell, wherein the valve stem has a plurality of the ring-shaped protrusions. The fuel cartridge for a fuel cell according to claim 2,
The sub-seal portion is disposed along the circumferential direction on the outer peripheral surface of the valve stem, the tapered inner wall surface having a diameter reduced toward the tip of the nozzle head, and is in contact with the tapered inner wall surface. A fuel cartridge for a fuel cell comprising a ring-shaped elastic member for sealing the liquid fuel flow path. The fuel cartridge for a fuel cell according to any one of claims 3 to 6,
A fuel cartridge for a fuel cell, wherein an elastic member is disposed along the tapered inner wall surface of the nozzle head. The fuel cartridge for a fuel cell according to claim 2,
The sub-seal portion includes the tapered inner wall surface that is reduced in diameter toward the tip of the nozzle head, an elastic member that is disposed along the tapered inner wall surface, and the elastic member that contacts the elastic member. A fuel cartridge for a fuel cell, comprising: a tip portion of the valve stem that seals a fuel flow path. The fuel cartridge for a fuel cell according to claim 2,
The sub seal portion is tapered toward the tip of the nozzle head and tapered toward the tip of the valve stem, and contacts the tapered inner wall of the nozzle head. A fuel cartridge for a fuel cell comprising a tapered outer peripheral surface for sealing the liquid fuel flow path. A fuel cartridge for a fuel cell according to any one of claims 1 to 9,
A fuel cell body comprising: a fuel storage portion having a socket portion that is detachably connected to the nozzle portion of the fuel cartridge; and an electromotive portion that is supplied with the liquid fuel from the fuel storage portion and performs a power generation operation. A fuel cell characterized by the above. The fuel cell according to claim 10, wherein
The electromotive unit includes a fuel electrode, an oxidant electrode, and an electrolyte membrane sandwiched between the fuel electrode and the oxidant electrode. The fuel cell according to claim 11, wherein
The fuel cell further comprises a gas permselective membrane interposed between the fuel storage portion and the electromotive portion and supplying a vaporized component of the liquid fuel to the fuel electrode.

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