JP2007335144A - Non-stationary fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-stationary fuel cell system which can feed the liquid with high stability even when up/down variation or inclination in fuel surface occurs in the liquid level within a liquid storage tank for the fuel or the like, and can operate with high stability even in the event of substantial postural change. <P>SOLUTION: The non-stationary fuel cell system has at least one tank 11 for storage of the liquid 12 including any one of fuel, water or mixture of the fuel and water. One end 13a of a supply piping 13 for feeding the liquid 12 in the tank 11 to fuel cells is inserted into the tank 11; and a liquid immersion means 14 consisting of a floater 15, weight 16, and the like is provided at one end 13a of the supply piping 13 in order to immerse a top end 13b of the supply piping 13 in the liquid irrespective of up/down variation and surface inclination in the liquid level 12a within the tank 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a non-stationary fuel cell system, and more particularly to a non-stationary fuel cell system that can stably supply liquid even if the liquid level in a tank storing liquid of either fuel or water or a mixture thereof is changed or inclined. The present invention relates to a stationary fuel cell system.

  In recent years, the fuel cell system is not only a stationary type represented by a fuel cell system for a cogeneration system, but also a non-stationary type fuel cell system such as a fuel cell for electric vehicles and a fuel cell for portable electronic devices. It has been actively proposed. For example, as a ubiquitous mobile power source that does not require charging from an AC adapter, a direct oxidation fuel cell that supplies fuel directly to the anode electrode has attracted attention, and active research and development has been conducted.

In a direct oxidation fuel cell, a fuel oxidation reaction occurs at the anode electrode and an oxygen reduction reaction occurs at the cathode electrode. The reaction formula for a direct methanol fuel cell using methanol as the fuel is
_{Anode: CH 3 OH + H 2 O} → CO 2 + 6H + + 6e - (1)
Cathode: 3/2 O ₂ + 6H ⁺ + 6e ⁻ → 3H ₂ O (2)
It is.

  As in the formula (1), methanol and water are required for the anode reaction. However, when both methanol and water are supplied from the outside, it is necessary to provide a space for storing water in a tank or cartridge for storing fuel. There is a corresponding decrease in energy density per volume. Therefore, in a direct methanol fuel cell, it is generally performed that a part of the water generated at the cathode is recovered in the system and reused according to the equation (2).

  Furthermore, instead of collecting only water, the fuel and water discharged from the anode and cathode of the fuel cell are once collected, and mixed with the high-concentration fuel in the fuel tank and the fuel adjusted to a predetermined concentration again. A circulating fuel system used for power generation has also been proposed. Referring to FIG. 3, reference numeral 1 denotes a fuel cell, which is composed of a cell stack in which a plurality of cells configured by disposing a membrane electrode assembly (MEA) so as to face the separator channel surface are stacked. A predetermined concentration of fuel in the fuel tank 2 and water in the recovery tank portion 3a of the gas-liquid separator 3 are mixed with the anode of the fuel cell 1 by the first pump 5 via valves 4a and 4b. The fuel is supplied to the tank 6 and diluted to a predetermined concentration. The fuel diluted to the predetermined concentration is supplied from the mixing tank 6 through the valve 7 by the second pump 8, and the air fan 9 is supplied to the cathode of the fuel cell 1. The fuel cell 1 generates power by supplying air at. In such a fuel cell system, not only the fuel tank 2 but also various liquid storage tanks such as a recovery tank portion 3a and a mixing tank 6 of the gas-liquid separator 3 and a dilution water tank provided separately in some cases. Is provided.

  In the fuel cell system used for the portable device, the fuel is supplied from the main tank in the fuel cartridge to the spare tank provided with the impregnation material at least near the take-out port by the first pump, By supplying a sufficient amount of fuel for power generation from the reserve tank to the fuel cell with the second pump, the fuel can be supplied stably regardless of the attitude and inclination of the portable device. It is known (see, for example, Patent Document 1).

As another example, a bubble trap is provided in the liquid passage on the upstream side of the micropump for supplying fuel to the fuel cell, and a bubble vent for discharging bubbles captured by the bubble trap to the outside of the liquid passage is provided. A configuration in which bubble removing means is provided is known (for example, see Patent Document 2).
JP 2004-288574 A JP 2006-2709 A

  By the way, the non-stationary fuel cell system may change its posture freely and may cause a large inclination. Therefore, even in the configuration shown in FIG. 3, various liquids such as a fuel tank are not affected by the posture. It is necessary to stably supply liquid such as fuel from the storage tank to the fuel cell 1, but one end of a supply pipe connected to the pump is inserted into a tank having a general configuration, and its tip is simply placed at the bottom. Depending on the posture, the tip of the supply pipe opens out of the liquid level, and the air is sucked into the pump and air enters the pump, causing the fuel supply to become unstable or stop. There is a problem of end.

  On the other hand, in the configuration described in Patent Document 1, fuel is supplied from the main tank to the spare tank provided with the impregnating material so that the fuel is always almost full. The possibility of air entering the second pump to be supplied can be almost eliminated, but a separate tank and a supply structure are necessary, so the structure is complicated and costly. There is a problem that fuel may not be stably supplied to the fuel cell due to stagnant fuel supply to the fuel cell for a long time.

  Moreover, although the structure described in patent document 2 is a structure which can stabilize the flow volume characteristic of a micro pump by removing the bubble mixed in the fuel in the upstream of a micro pump, it supplies in a fuel tank. In the case of an inclined posture in which the tip of the tube goes out of the liquid level of the fuel tank, it cannot cope with the stable supply of fuel.

  In view of the above-described conventional problems, the present invention can stably supply liquid even if the liquid level in a tank for storing liquid such as fuel is changed vertically or inclined, and is stable even if the posture changes greatly. An object of the present invention is to provide a non-stationary fuel cell system that operates in the same manner.

  The non-stationary fuel cell system of the present invention is a non-stationary fuel cell system having at least one tank for storing a liquid of either fuel or water or a mixture thereof, and the liquid in the tank is sent to the fuel cell. One end of the supply pipe to be fed is inserted into the tank, and the one end of the supply pipe is immersed in the liquid so that the tip of the supply pipe is immersed in the liquid regardless of the vertical change and inclination of the liquid level in the tank. Means are provided.

  According to this configuration, a non-stationary fuel in which one end of a supply pipe is inserted into a tank in which a liquid of fuel, water, or a mixture thereof is stored and the liquid in the tank is supplied to the fuel cell. In the battery system, the tip of one end of the supply pipe inserted into the tank by the liquid immersion means can be kept immersed in the liquid regardless of the vertical change and inclination of the liquid level in the tank. Because there is no risk of air being drawn from the tip of the pump and entering the pump, even if the posture changes freely and a large inclination occurs, stable operation by stably feeding liquid such as fuel to the fuel cell Can be secured.

  Further, if the immersion means is composed of a float provided at an appropriate length from the tip of one end of the supply pipe and a weight provided between the float and the tip of the supply pipe, one end of the supply pipe By simply providing a float and weight, the tip of the supply pipe is opened at a predetermined depth from the liquid level in a state where it is stably maintained in a vertical posture with respect to the liquid level. Can be surely prevented.

  Further, as a means for immersing in liquid, even if constituted by a surface having a high hydrophilicity formed on a contact surface between the float provided at a position of an appropriate length from the tip of one end of the supply pipe and the liquid surface of the float, Since the bottom surface of the float is kept in close contact with the liquid surface by surface tension, the front end of the supply pipe is maintained in a vertical posture with respect to the liquid surface without a weight in the same manner as described above. It opens at a position, and air suction can be stably and reliably prevented.

  In addition, if a flexible portion is provided in the upper part of the float at one end of the supply pipe, the followability of the float to the liquid surface is further improved, and the suction of air can be prevented more stably.

  Further, when the supply pipe and the tank wall are coupled at a portion that penetrates the wall surface of the tank of the supply pipe, and the tank wall around the coupling portion has a structure having elasticity and flexibility, the liquid level changes vertically. And the connecting part of the supply pipe and the tank wall can be easily displaced according to the inclination, and one end of the supply pipe can be moved freely, so that the supply pipe can be slid and tilted through the tank wall and supplied. The above-described effects can be ensured with a simple configuration without applying a complicated configuration in which one end of the tube is configured to be stretchable.

  In addition, if the periphery of the joint portion of the tank wall with the supply pipe has a bellows structure, the simple effect of the bellows structure can provide elasticity and flexibility. can do.

  According to the non-stationary fuel cell system of the present invention, the tip of one end of the supply pipe inserted into the tank by the liquid immersion means is immersed in the liquid regardless of the vertical change and inclination of the liquid level in the tank. Since the air can be sucked from the tip of the supply pipe and there is no danger of air entering the pump, the fuel cell can stably hold liquids such as fuel even if the posture changes freely and a large tilt occurs. Thus, stable operation can be ensured by feeding.

  Hereinafter, an embodiment of a non-stationary fuel cell system of the present invention will be described with reference to FIGS. 1 and 2. Note that the entire configuration of the non-stationary fuel cell system is basically the same as that of the conventional example described with reference to FIG.

  In FIG. 1, reference numeral 11 denotes a fuel tank 2, a recovery tank section 3a of a gas-liquid separator 3, a mixing tank 6, a dilution water tank (not shown), etc. in the non-stationary fuel cell system shown in FIG. It is a tank for storing liquid, and stores a liquid 12 such as fuel, water or a mixture thereof. Reference numeral 13 denotes a supply pipe that supplies the liquid 12 in the tank 11 to the outside, and is configured to supply the liquid 12 to the mixing tank 6, the fuel cell 1, and the like through the valve 21 by the pump 22. ing.

  One end 13 a of the supply pipe 13 is inserted into the tank 11, and the end 13 b of the supply pipe 13 is inserted into one end 13 a of the supply pipe 13 regardless of the vertical change and inclination of the liquid level 12 a in the tank 11. In-liquid dipping means 14 for dipping the liquid in the liquid is provided. This submerged immersion means 14 is constituted by a floating 15 on a disk provided at an appropriate distance from the tip 13 b of the supply pipe 13 and a weight 16 provided between the float 15 and the tip 13 b of the supply pipe 13. Has been. In addition, a flexible portion 17 configured to be freely bent by a bellows structure is provided in an upper portion of the float 15 in the one end portion 13a of the supply pipe 13.

  One end 13a of the supply pipe 13 passes through the upper wall 11a of the tank 11 and is inserted into the tank 11, and the supply pipe 13 passes through the upper wall 11a. The wall 11a is integrally coupled in a liquid-tight state. A ring-belt-shaped bellows portion 19 is provided around the coupling portion 18 of the upper wall 11a so that the circumference of the coupling portion 18 of the supply pipe 13 and the upper wall 11a has elasticity and flexibility. Further, a flexible portion 20 is provided at a suitable location outside the upper wall 11a of the tank 11 of the supply pipe 13 so that the supply pipe 13 can be deformed by following the displacement of the one end portion 13a of the supply pipe 13 without resistance. ing. In addition, when the outer part of the tank 11 of the supply pipe 13 is made of a flexible tube, it is naturally not necessary to provide the flexible part 20 separately.

  Any of the flexible parts 17 and 20 and the bellows part 19 may be any material that is excellent in chemical resistance, heat resistance, and bending durability. For example, a fluororesin material can be suitably used.

  In the above configuration, when the non-installation type fuel cell system having the above configuration is mounted on, for example, a portable personal computer or the like, the overall attitude of the non-installation type fuel cell system greatly changes, and the inside of the tank 11 The liquid level 12a is greatly inclined or moved up and down, and the liquid level 12a changes up and down due to consumption of fuel and the like. Even in such a case, the tip 13b of the supply pipe 13 inserted into the tank 11 by the liquid immersion means 14 is always maintained in a state of being immersed in the liquid 12, so that the supply pipe 13 Since there is no fear that air is sucked into the pump 22 from the tip 13b, even if the posture changes freely and a large inclination occurs, liquid such as fuel is stably fed to the fuel cell 1 and is stable. Can be ensured.

  In the illustrated example, the liquid immersion means 14 is constituted by a float 15 provided in the vicinity of the tip 13b of the supply pipe 13 and a weight 16 provided in the lower part thereof. For example, as shown in FIG. In addition, even when the liquid level 12a is greatly inclined, the tip 13b of the supply pipe 13 is maintained at a predetermined depth from the liquid level 12a in a state where the tip 13b is stably maintained in a vertical posture with respect to the liquid level 12a by the float 15 and the weight 16 Since the opening is made at this position, air suction can be stably and reliably prevented with a simple and low-cost configuration in which the float 15 and the weight 16 are provided at the one end 13a of the supply pipe 13.

  Furthermore, since the flexible part 17 is provided in the upper part of the float 15 in the one end part 13a of the supply pipe | tube 13, the followability with respect to the liquid level 12a of the float 15 improves more, and prevents the suction of air more stably. Can do.

  In addition, the supply pipe 13 and the upper wall 11a are coupled by a coupling portion 18 at a portion passing through the upper wall 11a of the tank 11 of the supply pipe 13, and the bellows is provided with stretchability and flexibility around the coupling portion 18. Since the portion 19 is provided, as shown in FIG. 2 (b) in particular, even when the liquid level 12a is greatly lowered as the liquid 12 is consumed, the bellows portion 19 is greatly deformed following that. Since the coupling portion 18 is displaced and the one end portion 13a of the supply pipe 13 can be freely lowered, the tip 13b of the supply pipe 13 is stably maintained in a vertical posture with respect to the liquid surface 12a as described above. Since the opening is made at a predetermined depth from the liquid surface 12a, air suction can be stably and reliably prevented. In addition, with this configuration, it is necessary to apply a complicated configuration in which the supply pipe 13 is slidably or tiltably penetrated through the upper wall 11a of the tank 11 or one end of the supply pipe 13 is configured to be extendable / contractable. Therefore, the above-described effects can be ensured with a simple and low-cost configuration.

  In the above description of the embodiment, the liquid immersion means 14 is exemplified by the float 15 and the weight 16. However, the float 15 provided at an appropriate length from the tip 13 b of the supply pipe 13 and the float 15 are provided. You may comprise in the surface layer (not shown) with high hydrophilicity formed in the contact surface with the 15 liquid level 12a. If comprised in this way, since the lower surface of the float 15 will be maintained in the state closely_contact | adhered to the liquid level 12a with surface tension, the suction | inhalation of air can be prevented stably and reliably without providing the weight 16. FIG. .

  The non-stationary fuel cell of the present invention has one end of a supply pipe inserted into the tank regardless of the vertical change and inclination of the liquid level in the tank in which the liquid of either fuel or water or a mixture thereof is stored. Even if the posture changes freely and a large inclination occurs, the fuel cell can maintain the tip of the part immersed in the liquid and there is no risk of air being sucked in from the tip of the supply pipe and entering the pump. As a power source for portable electronic devices such as mobile phones, personal digital assistants (PDAs), laptop computers, video cameras, etc. It is also useful for electric scooters and power sources for automobiles.

Sectional drawing which shows the arrangement | positioning state of the tank and supply pipe | tube of one Embodiment of the non-stationary fuel cell of this invention. The state at the time of use of the embodiment is shown, (a) is a sectional view in an inclined state, (b) is a sectional view in a state where the liquid level is lowered. FIG. 6 is an overall schematic configuration diagram of a conventional non-stationary fuel cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Fuel tank 3 Gas-liquid separator 3a Recovery tank 4a Valve 4b Valve 5 1st pump 6 Mixing tank 7 Valve 8 2nd pump 9 Air fan 11 Tank 12 Liquid 12a Liquid surface 13 Supply pipe 13a One end 13b Tip 14 Liquid immersion means 15 Floating 16 Weight 17 Flexible part 18 Coupling part 19 Bellows part 20 Flexible part 21 Valve 22 Pump

Claims (6)

  In a non-stationary fuel cell system having at least one tank for storing a liquid of either fuel or water or a mixture thereof, one end of a supply pipe for supplying the liquid in the tank to the fuel cell is provided in the tank. Non-stationary, characterized in that a liquid immersion means for immersing the tip of the supply pipe in the liquid irrespective of the vertical change and inclination of the liquid level in the tank is provided at one end of the supply pipe. Type fuel cell system.   2. The liquid immersion means comprises a float provided at an appropriate length from the tip of one end of the supply pipe, and a weight provided between the float and the tip of the supply pipe. Non-stationary fuel cell system.   The liquid immersion means comprises a float provided at a position of an appropriate length from the tip of one end of the supply pipe, and a highly hydrophilic surface formed on a contact surface of the float with the liquid surface. The non-stationary fuel cell system according to claim 1.   4. The non-stationary fuel cell system according to claim 2, wherein a flexible portion is provided in an upper portion of the float at one end of the supply pipe. 5.   The supply pipe and the tank wall are coupled at a portion of the supply pipe that penetrates the wall surface of the tank, and the tank wall around the coupling portion has a structure having elasticity and flexibility. The non-stationary fuel cell system according to any one of claims 1 to 4. 6. The non-stationary fuel cell system according to claim 5, wherein the tank wall has a bellows structure around a joint portion with the supply pipe.

Images