JP2006221828A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system that can be miniaturized. <P>SOLUTION: A fuel supply 30 is arranged between a power generator 10 for generating power by the reaction between hydrogen and oxygen and a storage 20 for storing liquid fuel. The fuel supply 30 vaporizes the liquid fuel by heat, and supplies it to the power generator 10 by the expansion of the volume with the liquid fuel as a jet, namely by a thermal ink jet system, thus dispensing with a pump and an actuator for conveying the liquid fuel from the storage 30 to the power generator 10 for miniaturization. The storage 30 has a fuel tank chamber 31 for storing the liquid fuel, and a pressure control mechanism 32 for controlling the internal pressure of the fuel tank chamber 31, thus preventing the leakage of the liquid fuel in stop, the backward flow of bubbles in operation, or the like. Air is supplied to the pressure control mechanism 32 as gas for pressurization by an air supply path 51A branched from an air supply pump 51. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell system that supplies liquid fuel directly to a power generation unit, or supplies hydrogen generated by reacting liquid fuel to a power generation unit to generate power, and in particular, a fuel cell that uses an aqueous methanol solution as the liquid fuel. About the system.

  In recent years, the need for alternative clean energy sources that can replace fossil fuels such as petroleum has increased, and for example, hydrogen (gas) fuel has attracted attention. Hydrogen is a clean and inexhaustible ideal energy source because it contains a large amount of chemical energy per unit mass and does not release harmful substances or global warming gases when used.

  An example of such an energy conversion method using hydrogen is a fuel cell. A fuel cell chemically reacts hydrogen and oxygen to generate water and extract current, and direct liquid such as hydrogen solid polymer type and direct methanol type depending on the supply system and reaction mechanism of hydrogen as fuel. It is classified into fuel type, fuel reforming type, phosphoric acid type, molten solid polymer type, solid oxide type and the like.

  FIG. 21 shows an example of a conventional fuel cell system. This fuel cell system is a liquid fuel reforming type, and includes a power generation unit 210, a reforming unit 270, and a storage unit 220. The power generation unit 210 and the reforming unit 270 are connected by a first fuel supply pump 311 and a hydrogen transport connecting tube 312, and the reforming unit 270 and the storage unit 220 are connected by a second fuel supply pump 321 and a liquid fuel transport. They are connected by a connecting tube 322.

  The power generation unit 210 has a configuration in which a power generation body 211 is disposed between an anode electrode 212 and a cathode electrode 213, and a current extracted from the power generation unit 210 is a device main body (not shown) via a rectifier 240. To be supplied to. Hydrogen from the reforming unit 270 is supplied to the anode 212 side, oxygen is supplied from the air supply pump 251 to the cathode electrode 213 side, and a gas-liquid separator 252 is connected. The power generation unit 210 is temperature-controlled by a power generation unit temperature controller 291.

The reforming unit 270 is supplied with a methanol aqueous solution (CH ₃ OH, H ₂ O) as a liquid fuel from the storage unit 220, and generates hydrogen (H ₂ ) by reacting the methanol aqueous solution. The temperature of the reforming unit 270 is adjusted by a reforming unit temperature controller 292.

  The first fuel supply pump 311, the second fuel supply pump 321, the rectifier 240, the air supply pump 251, the gas-liquid separation device 252, the power generation unit temperature controller 291 and the reforming unit temperature controller 292 are supplemented respectively. Power is supplied from the power supply 260.

  As described above, in the conventional fuel cell system, hydrogen and oxygen are generally supplied to the power generation unit 210 by using a pump and an actuator on both the anode electrode 212 side and the cathode electrode 213 side. A fuel cell system using a hydrocarbon-based liquid fuel typified by methanol is expected as a power source for portable devices because of easy fuel handling, and further miniaturization and higher efficiency are required. Nevertheless, at present, only the pumps have been reduced in size, and there has been almost no report about the epoch-making simplification accompanied by the reduction of auxiliary equipment members.

Conventionally, for example, it has been proposed to reduce the size of the reformer by configuring the reformer with MEMS (Micro Electro Mechanical Systems) (see, for example, Patent Document 1).
JP 2003-45459 A

  However, the configuration described in Patent Document 1 requires a conventional pump and fuel supply pipe for fuel supply, and cannot sufficiently meet the demand for further simplification and miniaturization. There was a problem.

  The present invention has been made in view of such a problem, and an object thereof is to provide a fuel cell system that can be miniaturized.

  A first fuel cell system according to the present invention includes a power generation unit that generates power by receiving supply of liquid fuel and air, a storage unit that stores liquid fuel, and vaporizes the liquid fuel supplied from the storage unit by heat, And a fuel supply unit that supplies liquid fuel as a jet to the power generation unit due to the expansion of the volume.

  A second fuel cell system according to the present invention includes a power generation unit that generates power by a reaction between hydrogen and oxygen, a reforming unit that reacts liquid fuel to generate hydrogen, and supplies the generated hydrogen to the power generation unit. , A storage unit that stores liquid fuel, and a fuel supply unit that vaporizes the liquid fuel supplied from the storage unit by heat and supplies the liquid fuel as a jet to the reforming unit by expanding its volume. .

  In the first fuel cell system of the present invention, the liquid fuel supplied from the storage unit to the fuel supply unit is vaporized by heat, and the liquid fuel is supplied as a jet to the power generation unit by expansion of the volume. The power generation unit receives the supply of liquid fuel and air from the fuel supply unit and generates power.

  In the second fuel cell system of the present invention, the liquid fuel supplied from the storage unit to the fuel supply unit is vaporized by heat, and the liquid fuel is supplied as a jet to the reforming unit by expansion of its volume. The liquid fuel supplied to the reforming section reacts to generate hydrogen. The generated hydrogen is supplied to the power generation unit, and power generation is performed by a reaction between hydrogen and oxygen in the power generation unit.

  According to the first fuel cell system of the present invention, the liquid fuel is vaporized by heat, and the fuel supply unit that supplies the liquid fuel to the power generation unit as a jet by expansion of the volume is provided. According to the fuel cell system of the present invention, a fuel supply unit that vaporizes liquid fuel by heat and supplies the liquid fuel as a jet to the reforming unit due to the expansion of its volume is reduced, thereby reducing the number of pumps and actuators that transport the liquid fuel And can be miniaturized. In particular, according to the first fuel cell system of the present invention, the required amount of liquid fuel can be supplied to the power generation unit according to the output, and supply by crossover and carbon dioxide gas, which has been a problem in the past, Road clogging can be reduced. Therefore, it is possible to use a liquid fuel with a higher concentration, and high efficiency and high output can be expected.

  In addition, if the storage unit is provided with a fuel tank chamber for storing liquid fuel and a pressure control mechanism for controlling the internal pressure of the fuel tank chamber, liquid fuel leakage at the time of stopping is prevented, and at the time of operation. Bubble backflow from the fuel supply unit can be suppressed, and liquid fuel can be stably supplied to the power generation unit or the reforming unit.

  Furthermore, if an air supply pump that supplies air to the power generation unit and the pressure control mechanism is provided, air is supplied to both the power generation unit and the pressure control mechanism using a common air supply path. And further miniaturization can be achieved.

  In addition, if an exhaust supply path for supplying the exhaust from the power generation unit to the pressure control mechanism is provided, the exhaust from the power generation unit can be used effectively.

  Furthermore, in the second fuel cell system of the present invention, by controlling the internal pressure of the reforming unit to be higher than that of the power generation unit, hydrogen generated using the pressure difference is supplied to the power generation unit. If so, pumps and actuators for transporting hydrogen can be reduced, and further miniaturization becomes possible.

  In addition, if the reforming section has a laminated structure of a reforming reaction layer, a hydrogen separation membrane, and a hydrogen supply plate, and a lead-out path is provided on the surface of the hydrogen supply plate in contact with the hydrogen separation membrane, the reforming reaction layer The hydrogen generated in the above can be separated by the hydrogen separation membrane and moved to the lead-out path, while the movement of by-products such as carbon dioxide to the lead-out path can be suppressed. Therefore, the hydrogen partial pressure control can be facilitated and the efficiency of the power generation unit can be increased.

  Furthermore, if the power generation unit is integrated with the hydrogen supply plate so as to face the lead-out path in parallel with the hydrogen separation membrane, the reforming unit and the power generation unit can be combined and integrated. Therefore, it is possible to realize a fuel cell system with a simple structure and further reduced in size.

  In addition, the lead-out path can be simplified if the part of the lead-out path that corresponds to the power generation section is a negative-electrode channel that can supply hydrogen to the power generation section substantially evenly. Therefore, heat loss at the time of hydrogen transfer can be reduced, and the thermal efficiency of the entire fuel cell system can be improved.

  Furthermore, if a check mechanism is provided at the inlet for introducing liquid fuel in the reforming section, it is possible to prevent the fuel from flowing back from the inlet even if the fuel expands due to vaporization. And the internal pressure of the reforming section can be kept high. Therefore, hydrogen can be sent to the power generation unit by effectively using the increase in internal pressure due to the reaction of the fuel.

  In addition, if a pressure control valve is provided at the outlet for discharging the by-product due to the reaction of the liquid fuel in the reforming section, the gas may flow back from the inlet depending on the operating conditions. Can be prevented, and stable fuel supply can be performed.

  Furthermore, if a heat insulating layer is provided on the surface of the hydrogen supply plate, the amount of heat radiation can be reduced, the energy conversion efficiency of the entire fuel cell system can be increased, and stable driving can be performed.

  Hereinafter, embodiments of the present invention will be described in detail.

(First embodiment)
FIG. 1 shows the overall configuration of the fuel cell system according to the first embodiment of the present invention. This fuel cell system is of a direct methanol type used as a power source for portable devices, and includes, for example, a power generation unit 10, a storage unit 20, and a fuel supply unit 30.

  The power generation unit 10 generates power by receiving supply of liquid fuel and air. The power generation unit 10 has a configuration in which the power generation body 11 is disposed between the anode electrode 12 and the cathode electrode 13, and the current extracted from the power generation unit 10 is connected to a device main body (not shown) via a rectifier 40. Z)). For example, a 50 mol% aqueous methanol solution is supplied as liquid fuel from the fuel supply unit 30 to the anode electrode 12 side of the power generator 11, and air is supplied to the cathode electrode 13 side by an air supply pump 51, A liquid separator 52 is connected. The anode electrode 12 and the cathode electrode 13 are preferably made of a material excellent in gas tightness, for example, a resin molded body containing a carbon material. In addition, electric power is supplied to the rectifier 40 from the auxiliary power supply 60 comprised, for example with the lithium ion battery.

  The storage unit 20 stores liquid fuel. The storage unit 20 may be of a tank type that can be permanently used by replenishing when the storage amount decreases, but the cartridge type that is replaced with a new one when the stored liquid fuel is used is more compact. Is advantageous. The storage unit 20 and the fuel supply unit 30 may be connected via a connection tube (not shown) or the like, but the storage unit 20 is directly connected without using a connection tube (not shown). The size can be further reduced if it can be attached to the fuel supply unit 30.

  The fuel supply unit 30 vaporizes the liquid fuel supplied from the storage unit 20 by heat, and supplies the liquid fuel to the power generation unit 10 as a jet by expansion of its volume, that is, by a thermal ink jet method. Thereby, in this fuel cell system, the pump and actuator which transport liquid fuel from the storage part 20 to the electric power generation part 10 can be reduced, and size reduction is possible.

  As shown in FIG. 2, the fuel supply unit 30 includes a plurality of supply head units 31. These supply head portions 31 are arranged in a matrix on a substrate (not shown) made of glass, aluminum oxide (alumina), silicon (Si), or the like.

  As shown in FIG. 3, the supply head unit 31 has a liquid chamber 32 in which a flow path 34 is formed by an orifice forming plate 33 having a partition wall 33 </ b> A. A heater 35 is provided in the flow path 34, and the vicinity thereof serves as a vaporization chamber 34A. A nozzle 36 is provided in the vaporizing chamber 34 </ b> A so as to face the heater 35. The discharge amount, discharge frequency, and discharge pressure for one time are determined by the shape of the nozzle 36, the size of the flow path 34 formed by the orifice forming plate 33, and the size of the liquid chamber 32. In the fuel supply system 30 of the fuel cell system, the frequency is not greatly involved, but the discharge amount and the discharge pressure are matters related to the liquid fuel supply.

  The heater 35 is preferably made of a material capable of generating heat up to, for example, 300 ° C. or higher. Specifically, a metal such as silicon (Si), tungsten (W), molybdenum (Mo), niobium (Nb), or chromium (Cr), an alloy, or a compound thereof may be used, and the alloy may be nickel (Ni) -chromium. Alloy (for example, nickel 78 wt%, chromium 20 wt%, other 2 wt%), iron-chromium alloy or tantalum nichrome alloy (for example, nickel 58 wt%, chromium 16.5 wt%, iron 23.0 wt%, silicon 1.2 wt%), etc. Can be mentioned. The heater 35 is connected to a heating control circuit 37. The heating control circuit 37 may be formed inside the orifice forming plate 33 or may be installed outside the supply head unit 31.

  In the supply head 31, the liquid fuel is introduced into the liquid chamber 32 by capillary action, and is guided to the vaporization chamber 34 </ b> A through the flow path 34. The liquid fuel introduced into the vaporization chamber 34 </ b> A is usually heated to about 300 ° C., for example, by the heater 35 to cause film boiling to become the vaporized fuel 38. Due to the expansion of the volume, the liquid fuel in the vicinity of the nozzle 36 in the vaporization chamber 34 </ b> A is discharged from the nozzle 36 as a jet 39 and supplied to the power generation unit 10.

Regarding the amount of fuel supplied by the fuel supply unit 30, the liquid fuel needs to be sufficiently supplied when the power generation unit 10 requires the maximum output. Assuming that the volume of liquid fuel discharged from one supply head unit 31 at a time is 5 pL (picoliter) and the discharge frequency is 30 kHz, the discharge amount of liquid fuel from one supply head unit 31 per minute is 1. 5 * 10 ⁻¹⁰ m ³ /s=9.0*10 ⁻⁴ cm ³ / min. Here, it is assumed that the maximum output of the power generation unit 10 is 100 mW (0.25 V, 400 mA) / cm ² , and is necessary when the thermoelectric conversion efficiency of the liquid fuel on the catalyst surface according to Chemical Formula 1 is 70%. When the liquid fuel is calculated, the liquid fuel consumed in one minute in the power generation unit 10 is 3.6 * 10 ⁻³ cm ³ / min, and in order for the power generation unit 10 to exhibit a sufficient power generation capability, the supply head unit At least 4 or more 31 is required per 1 cm ² . That is, it is preferable that the maximum consumption amount Q1 of liquid fuel in the power generation unit 10 and the maximum discharge amount Q2 of liquid fuel in the fuel supply unit 30 satisfy Formula 1.

(Chemical formula 1)
CH ₃ OH + H ₂ O → 3H ₂ + CO ₂

(Equation 1)
Q1 ≦ Q2

  The storage unit 20 includes a fuel tank chamber 21 that stores liquid fuel and a pressure control mechanism 22 that controls the internal pressure of the fuel tank chamber 21. The aqueous methanol solution, which is a liquid fuel, has a low viscosity, and depending on the direction of the supply head unit 31, there is a risk that the liquid fuel leaks from the nozzle 37 when stopped. Can be prevented. In addition, during operation, the power generation unit 10 is not necessarily at atmospheric pressure, but rather may be in a pressurized state, but by providing the pressure control mechanism 22 in the storage unit 20, a stable pressure is applied to the liquid chamber 32. This is because liquid fuel can be supplied, pressure at each position such as the liquid fuel supply path to the liquid chamber 32 and the nozzle 36 can be appropriately maintained, and bubble backflow from the supply head unit 31 can be suppressed. .

  The pressure control mechanism 22 controls the internal pressure of the fuel tank chamber 21 using, for example, a pressurizing gas. As the pressurizing gas, for example, as shown in FIG. 1, air can be supplied through an air supply path 51 </ b> A branched from the air supply pump 51. If it does in this way, it will become possible to supply air to both the electric power generation part 10 and the pressure control mechanism 22 using a common air supply path | route, and can achieve further size reduction.

  For example, as shown in FIG. 4, an exhaust supply path 22 </ b> A for supplying exhaust from the power generation unit 10 to the pressure control mechanism 22 may be provided. If it does in this way, the exhaust_gas | exhaustion from the electric power generation part 10 can be utilized effectively.

  The pressure control mechanism 22 may adopt a system in which the pressurizing gas is directly supplied into the fuel tank chamber 21 to pressurize, but as shown in FIG. 5 or FIG. 6, the fuel tank chamber is used to introduce the pressurizing gas. It is preferable to provide a pressure chamber 23 different from 21. This is because air bubbles can be prevented from entering the fuel tank chamber 21. The pressurizing chamber 23 is separated from the fuel tank chamber 21 by the movable wall 23A as shown in FIG. 5, or the bag body 23B installed in the fuel tank chamber 21 as shown in FIG. It can be constituted by. The bag body 23B can be made of, for example, a plastic film such as polyethylene, polypropylene, nylon, or PET.

  In this pressure control mechanism 22, during operation, pressurization gas is introduced from the gas inlet 23 </ b> C into the pressurization chamber 23, and the internal pressure of the pressurization chamber 23 is adjusted so that the pressure in the vicinity of the nozzle 36 is appropriate for discharging liquid fuel. Control to a preset value. This pressure control may be performed by a system in which a back pressure is directly applied to the fuel supply port 21A of the fuel tank chamber 21, or, as shown in FIGS. 23D may be provided and this pressure control valve 23D may be used. The pressure control valve 23D can be configured by a swing type, a tilting type, a lift type, a screw tightening check valve or the like.

  On the other hand, when stopping, the air supply pump 51 stops and the introduction of the pressurizing gas is also stopped. At this time, a back pressure control valve (not shown) is provided in the air supply pump 51, and a signal from the back pressure control valve and a signal from a circuit (not shown) incorporating a control program or the like are provided. By the combination, the pressure in the air supply path 51A is controlled to a preset value so that the internal pressure of the pressurizing chamber 23 and the pressure in the vicinity of the nozzle 36 are appropriate for preventing liquid fuel leakage. Thus, the equilibrium state between the pressure applied to the nozzle 36 at the time of stop and the internal pressure of the fuel tank chamber 21 can be controlled using the air supply path 51A.

  This fuel cell system can be manufactured, for example, as follows.

First, the power generation unit 10 having an effective area of, for example, 5 × 5 cm ² and a theoretical methanol usage calculated from the amount of supported catalyst of, for example, 3.6 × 10 ⁻³ cm ³ / min is formed.

Next, the supply head portions 31 shown in FIG. 3 having a discharge amount of, for example, 5 pL and a discharge frequency of, for example, 30 kHz are arranged at, for example, 4 pieces / cm ² to form the fuel supply portion 30 having a size of, for example, 5 × 5 cm ^2. . The fuel supply unit 30 is disposed on the anode electrode 12 side of the power generation unit 10.

Subsequently, for example, a 50 mol% methanol aqueous solution is stored as the liquid fuel, and a storage unit 20 having a capacity of, for example, 100 cc (inner diameter is, for example, 4 × 5 × 5 cm ³ ) is prepared. A bag body 23B made of, for example, polyethylene / polypropylene as shown in FIG. 6 is inserted into the storage unit 20 to form a pressurizing chamber 23, and a pressure control valve 23D is provided at the gas inlet 23C. Thereby, the pressure control mechanism 22 is formed in the storage unit 20. The internal pressure of the pressurizing chamber 23 during operation is set to be 1.5 atm, for example.

  After that, an air supply pump 51 having a maximum discharge amount of, for example, 1 NL / min is connected to the cathode 11 side of the power generation unit 10 and the pressure control mechanism 22. The air supply pump 51 is provided with a back pressure control valve (not shown), and is set so that a back pressure of +0.3 to 0.5 atm is applied to the air supply path 51A when stopped. Further, the rectifier 40 and the gas-liquid separator 52 are connected to the power generation unit 10, and commercially available lithium ion secondary batteries (US18650, 3) are disposed as the auxiliary power source 60. Thus, the fuel cell system shown in FIG. 1 is completed.

  In this fuel cell system, the liquid fuel stored in the storage unit 20 is supplied to the anode electrode 12 of the power generation unit 10 by the fuel supply unit 30 and generates protons and electrons by the reaction. Protons move to the cathode 13 through the power generator 11 and react with electrons and oxygen to generate water. Here, since the liquid fuel is vaporized by heat in the fuel supply unit 30 and the volume of the liquid fuel is supplied as a jet to the power generation unit 10 due to the expansion of the volume, a necessary amount of liquid fuel is supplied to the power generation unit 10 according to the output. Is supplied. Therefore, crossover and clogging of the supply path due to carbon dioxide gas are reduced, and the output is improved.

  As described above, in the present embodiment, the liquid fuel is vaporized by heat, and the fuel supply unit 30 that supplies the liquid fuel as a jet to the power generation unit 10 by the expansion of the volume is provided. Therefore, the pump that transports the liquid fuel And the number of actuators can be reduced, and the size can be reduced. In addition, a required amount of liquid fuel can be supplied to the power generation unit 10 according to the output, and clogging of the supply path due to crossover and carbon dioxide gas, which has been a problem in the past, can be reduced. Therefore, it is possible to use a liquid fuel with a higher concentration, and high efficiency and high output can be expected.

  Furthermore, since the storage unit 20 is provided with a fuel tank chamber 21 for storing liquid fuel and a pressure control mechanism 22 for controlling the internal pressure of the fuel tank chamber 21, liquid fuel leakage at the time of stoppage is prevented. The bubble backflow from the fuel supply unit 30 during operation can be suppressed, and the liquid fuel can be stably supplied to the power generation unit 10.

  In addition, since the air supply pump 51 that supplies air to the power generation unit 10 and the pressure control mechanism 22 is provided, a common air supply path is used for both the power generation unit 10 and the pressure control mechanism 22. Thus, it is possible to supply air, and further downsizing can be achieved.

  Furthermore, since the exhaust supply path 22A for supplying the exhaust from the power generation unit 10 to the pressure control mechanism 22 is provided, the exhaust from the power generation unit 10 can be used effectively.

(Second Embodiment)
FIG. 7 shows the overall configuration of the fuel cell system according to the second embodiment of the present invention. This fuel cell system is of a liquid fuel reforming type provided with a reforming unit 70 in addition to the power generation unit 10, the storage unit 20, and the fuel supply unit 30. Accordingly, the corresponding components will be described with the same reference numerals.

  The power generation unit 10 is the first except that the hydrogen transport connecting tube 81 and the hydrogen supply pump 82 are connected to the anode electrode 12 side and hydrogen is supplied from the reforming unit 70. The configuration is the same as that of the embodiment. Note that the temperature of the power generation unit 10 is adjusted by the first temperature controller 91.

  The storage unit 20 has the same configuration as that of the first embodiment. Exhaust from the power generation unit 10 is supplied as a pressurizing gas to the pressure control mechanism 22 through the exhaust supply path 22A, so that the exhaust from the power generation unit 10 can be used effectively. As the pressurizing gas, for example, as shown in FIG. 8, air can be supplied through an air supply path 51 </ b> A branched from the air supply pump 51. Thereby, air can be supplied to both the power generation unit 10 and the pressure control mechanism 22 by using a common air supply path, and further miniaturization can be achieved.

  The fuel supply unit 30 has the same configuration as that of the first embodiment except that liquid fuel is supplied to the reforming unit 70. The fuel supply unit 30 may directly discharge the liquid fuel into the reforming unit 70, or introduce the discharged liquid fuel into the reforming unit 70 through a connection tube (not shown). You may make it do. Since both the reaction temperature of the liquid fuel in the reforming unit 70 and the heating temperature of the heater 35 of the fuel supply unit 30 are usually about 300 ° C., for example, the reforming unit 70 and the fuel supply unit 30 are common second. The temperature can be adjusted by the temperature adjuster 92, whereby the fuel cell system can be further downsized.

The reforming unit 70 reacts the liquid fuel supplied from the fuel supply unit 30 to generate hydrogen, and supplies the generated hydrogen to the power generation unit 10. The reforming unit 70 includes, for example, copper / zinc (Zn) and aluminum (Al) as a catalyst in a substrate made of copper (Cu) at a molar ratio of copper: zinc: aluminum = 6: 3: 1. A reforming reaction layer containing ZnO / Al ₂ O ₃ is formed, and its reforming efficiency a is, for example, 90%. Carbon dioxide, which is a byproduct due to the reaction of the liquid fuel, is exhausted through a carbon dioxide separation membrane (not shown) for separating and discharging carbon dioxide.

  It is preferable that the maximum consumption amount Q1 of liquid fuel in the power generation unit 10 and the maximum discharge amount Q2 of liquid fuel in the fuel supply unit 30 satisfy Formula 2.

(Equation 2)
Q1 ≦ Q2 * a
(In Equation 2, a represents the reforming efficiency in the reforming unit 70.)

  Further, the reforming unit 70 may be provided with a humidifying layer (not shown) for hydrogen humidification as necessary. The humidification layer may be any layer that can mix water vapor with the generated hydrogen gas, but is preferably small and semi-solid. Furthermore, it is more preferable that it is made of a porous structure because the contact area can be increased. As a specific configuration of the humidifying layer, a three-dimensional porous structure having excellent heat resistance such as foamed nickel and polyamide porous body is used as a skeleton structure, and polyacrylic acid, polyvinyl alcohol or hyaluronic acid is formed on the surface thereof. Such a film having a water-absorbing polymer formed thereon may be mentioned. In the case where such a humidifying layer is provided, for example, a humidifying water tank and a moisture supply path may be separately provided. Furthermore, since steam is generated by power generation in the fuel cell system, for example, if the steam is exhausted via a humidification water tank, it is desirable in terms of reuse of the generated water.

  The power generation unit 10, the reforming unit 70, the storage unit 20, and the fuel supply unit 30 can be arranged as shown in FIG. 9, for example. Furthermore, for example, as shown in FIG. 10, it is possible to combine a plurality of power generation units 10, reforming units 70, and fuel supply units 30 and arrange storage units 20 of appropriate sizes. As a result, the fuel cell system can have a card type configuration, and a thin and small fuel cell system suitable for a power source for portable devices can be realized.

  This fuel cell system can be manufactured, for example, as follows.

First, a reforming reaction layer containing Cu / ZnO / Al ₂ O ₃ containing, for example, copper, zinc and aluminum as a catalyst in a molar ratio of copper: zinc: aluminum = 6: 3: 1 on a substrate made of copper, for example. Then, the reforming portion 70 having a reforming efficiency a of 90%, for example, is formed.

Further, for example, a power generation body 11 having a catalyst supporting area of 10 cm ² , a width of 40 mm, a length of 40 mm, and a thickness of 1 mm, and an anode electrode 12 and a cathode electrode 13 having a width of 40 mm, a length of 40 mm, and a thickness of 1 mm made of the above-described materials, for example. Are prepared, and the anode 12, the power generator 11, and the cathode 13 are laminated in this order to form the power generation unit 10.

Next, the supply head portions 31 shown in FIG. 3 having a discharge amount of, for example, 5.5 pL and a discharge frequency of, for example, 30 kHz are arranged at, for example, 4 pieces / cm ² to form the fuel supply portion 30. The fuel supply unit 30 is disposed on the reforming reaction layer side of the reforming unit 70.

Subsequently, for example, a 50 mol% aqueous methanol solution is stored as the liquid fuel, and a storage unit 20 having a capacity of, for example, 100 cc (inner diameter, for example, 4 × 5 × 5 cm ³ ) is prepared. A bag body 23B made of, for example, polyethylene / polypropylene as shown in FIG. 6 is inserted into the storage unit 20 to form a pressurizing chamber 23, and a pressure control valve 23D is provided at the gas inlet 23C. Thereby, the pressure control mechanism 22 is formed in the storage unit 20. The internal pressure of the pressurizing chamber 23 during operation is set to be 1.5 atm, for example.

  After that, an air supply pump 51 having a maximum discharge amount of, for example, 1 NL / min is connected to the cathode 11 side of the power generation unit 10 and the pressure control mechanism 22. Further, the rectifier 40 and the gas-liquid separator 52 are connected to the power generation unit 10, and a commercially available lithium ion secondary battery (US18650, 3 pieces) is disposed as the auxiliary power source 60. Although not shown in FIG. 7, a humidifying water tank having a capacity of 100 cc is disposed. Thus, the fuel cell system shown in FIG. 7 is completed.

  In this fuel cell system, the liquid fuel stored in the storage unit 20 is supplied to the reforming unit 70 by the fuel supply unit 30, and hydrogen is generated by the reaction of the liquid fuel. The generated hydrogen is supplied to the power generation unit 10 and power is generated by the reaction between hydrogen and oxygen. Here, the liquid fuel is vaporized by heat in the fuel supply unit 30, and the liquid fuel is supplied to the reforming unit 70 as a jet due to the expansion of its volume. Therefore, the temperature drop of the reforming unit 70 due to the liquid fuel supply is small, the temperature in the reforming unit 70 is always maintained at a temperature at which the catalytic activity can be expressed, and stable reforming efficiency can be obtained over the entire reforming unit 70. .

  As described above, in the present embodiment, the liquid fuel is vaporized by heat, and the fuel supply unit 30 that supplies the liquid fuel as a jet to the reforming unit 70 by the expansion of the volume is provided. Pumps and actuators can be reduced, and downsizing is possible.

  Further, as in the first embodiment, the storage unit 20 is provided with the fuel tank chamber 21 that stores the liquid fuel and the pressure control mechanism 22 that controls the internal pressure of the fuel tank chamber 21. While preventing liquid fuel leakage at the time of stopping, it is possible to suppress bubble backflow from the fuel supply unit 30 during operation and to stably supply liquid fuel to the power generation unit 10.

  Further, as in the first embodiment, the exhaust supply path 22A for supplying the exhaust from the power generation unit 10 to the pressure control mechanism 22 is provided, so that the exhaust from the power generation unit 10 can be used effectively. it can.

  In addition, since the air supply pump 51 that supplies air to the power generation unit 10 and the pressure control mechanism 22 is provided as in the first embodiment, both the power generation unit 10 and the pressure control mechanism 22 are provided. On the other hand, it becomes possible to supply air using a common air supply path, and further miniaturization can be achieved.

(Third embodiment)
FIG. 11 shows the overall configuration of a fuel cell system according to the third embodiment of the present invention. This fuel cell system has the same configuration as that of the second embodiment except that the configurations of the power generation unit 10 and the reforming unit 70 are further downsized and simplified. Accordingly, the corresponding components will be described with the same reference numerals.

  The power generation unit 10 has the same configuration as that of the second embodiment except that the temperature is adjusted by a temperature controller 90 that is common to the reforming unit 70 and the fuel supply unit 30. The storage unit 20 and the fuel supply unit 30 have the same configuration as that of the second embodiment.

  The reforming unit 70 has an inlet 71 for introducing liquid fuel from the storage unit 20 and an outlet 72 for discharging carbon dioxide, which is a byproduct due to the reaction of the liquid fuel. The discharge port 72 is provided with a carbon dioxide separation membrane (not shown) for separating and discharging carbon dioxide.

  12 shows a specific configuration of the power generation unit 10 and the reforming unit 70 shown in FIG. 11, and FIG. 13 shows a cross-sectional structure thereof. The reforming unit 70 reacts with liquid fuel to generate hydrogen, and a function of selectively permeating hydrogen necessary for power generation out of the gas generated in the reforming reaction layer 73 (hydrogen A hydrogen separation membrane 74 having a separation function and a hydrogen supply plate 75 are sequentially stacked. The hydrogen supply plate 75 has a lead-out path 76 for sending hydrogen that has permeated the hydrogen separation membrane 74 toward the power generation unit 10 on the surface in contact with the hydrogen separation membrane 74. Thereby, in this fuel cell system, the hydrogen generated in the reforming reaction layer 73 is separated by the hydrogen separation membrane 74 and moved to the outlet path 76, while the by-products such as carbon dioxide move to the outlet path 76. Can be suppressed.

  The hydrogen supply plate 75 extends longer than the stacked region of the hydrogen separation membrane 74 and the reforming reaction layer 73, and the power generation unit 10 is integrated so as to face the lead-out path 76 in the extended region. That is, on the same surface side of the hydrogen supply plate 75, the power generation unit 10 is disposed adjacent to the laminated portion of the hydrogen separation membrane 74 and the reforming reaction layer 73. With this configuration, in the present embodiment, the reforming unit 70 and the power generation unit 10 can be combined and integrated, and the overall size is reduced.

  Further, the hydrogen supply plate 75 also has a function as the anode 12 (see FIG. 11) in the power generation unit 10, and a portion of the lead-out path 76 corresponding to the power generation unit 10 is illustrated in FIG. Thus, the grid-shaped negative electrode flow path 12 </ b> A capable of supplying hydrogen substantially uniformly to the power generation unit 10 is formed. Thereby, the lead-out path 76 can be simplified, the heat loss at the time of hydrogen transfer can be reduced, and the thermal efficiency of the entire fuel cell system can be improved. A portion of the lead-out path 76 corresponding to the hydrogen separation membrane 74 is formed in a stripe shape.

  The reforming unit 70 supplies the hydrogen generated using the pressure difference to the power generation unit 10 by controlling the internal pressure to be higher than that of the power generation unit 10. Thereby, in this fuel cell system, as will be described later, hydrogen can be supplied to the power generation unit 10 without using a pump or an actuator, and the size can be reduced.

  In order to maintain the internal pressure of the reforming unit 70 in a stable and high state, a check mechanism 71A is provided at the introduction port 71 as shown in FIG. Thereby, it is possible to prevent the fuel that has undergone volume expansion due to vaporization from flowing back from the inlet 71, and to effectively utilize the increase in internal pressure due to the reaction of the liquid fuel and to send hydrogen into the power generation unit 10. it can.

  As the check mechanism 71A, a back pressure is directly applied to the introduction port 71 by the pressure control mechanism 22 of the storage unit 20 (see FIGS. 4 and 5), or a swing type, tilting type, lift type, screw tightening A check valve system such as a check valve can be used. If fuel flows backward, back pressure is generated in the inlet 71 or the valve body of the check valve, and the check valve can be automatically prevented. Regardless of the method.

  On the other hand, the discharge port 72 of the reforming unit 70 is provided with a pressure control valve 72A as shown in FIG. By providing the pressure control valve 72A, it is possible to prevent the gas from flowing backward from the inlet 21 depending on the operating conditions, and to perform stable fuel supply.

  The control pressure P1 by the check mechanism 71A and the control pressure P2 by the pressure control valve 72A preferably satisfy Equation 3. If this relationship is reversed, hydrogen generated in the reforming unit 70 may flow back to the fuel supply unit 30 side.

(Equation 3)
P2 <P1

  FIG. 15 shows a cross-sectional configuration of the reforming unit 70 shown in FIG. The reforming reaction layer 73 includes a catalyst support layer 73A having a catalyst for reacting liquid fuel, a heater 73B for heating the catalyst support layer 73A, and a coating made of copper or the like covering the catalyst support layer 73A. Member 73C. The covering member 73C is made of copper, for example, and a heater 73B is embedded in the covering member 73C.

The catalyst support layer 73A is obtained by supporting a catalyst for reducing liquid fuel to a hydrogen gas state on a material having gas permeability such as a porous material. The structure for supporting the catalyst on the porous material is not particularly limited, but a structure capable of exhibiting the catalytic ability with high efficiency is desirable. Examples of the catalyst include platinum (Pt) and its alloys, gold (Au) and its alloys, manganese (Mn), iron (Fe), zinc, copper, nickel (Ni) and their alloys, cobalt (Co) and its Alloys, as well as ruthenium (Ru). In particular, Cu / ZnO / Al ₂ O ₃ is preferable. It is because it is suitable as a power source for portable equipment because it exhibits catalytic ability in a lower temperature region.

  Further, in the catalyst support layer 73A, for example, a grid-shaped fuel supply path 73D as shown in FIG. 16 is formed, and the liquid fuel is distributed into the reforming unit 70 through the fuel supply path 73D. Can be done. In FIG. 15, the fuel supply path 73D is omitted.

  The heater 73B is preferably made of a metal having a large calorific value such as tantalum (Ta). The configuration of the heater 73B is not particularly limited as long as the catalyst support layer 73A can be efficiently heated. For example, it is desirable that the heater 73B is embedded in the vicinity of the catalyst support layer 73A in order to increase thermal efficiency.

  The constituent material of the hydrogen separation membrane 74 is not particularly limited as long as it is a material that can separate or occlude / release hydrogen. Specifically, for example, vanadium (V) and its alloys, palladium (Pd) and its alloys, Ni—Nb—Zr alloy, or lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd) And a thin film of a hydrogen storage alloy such as misch metal, which is a rare earth mixture. Examples of the organic material include those obtained by thinning polyethylene, nylon, PTFE (polytetrafluoroethylene), or the like. It is desirable that the hydrogen separation membrane 74 has a dimension that does not protrude from the covering member 73C and the hydrogen supply plate 75.

  The pressure Px at which the hydrogen separation membrane 74 selectively permeates hydrogen preferably satisfies Equation 4. In general, in order for the hydrogen separation membrane 74 to exhibit a hydrogen separation function, it is necessary to generate a differential pressure on both sides of the hydrogen separation membrane 74 to make the reforming section 70 have a positive pressure. If Equation 4 is not satisfied, the gas generated in the reforming unit 70 may flow back to the fuel supply unit 30 side, or the hydrogen separation function of the hydrogen separation membrane 74 may not be fully exhibited.

(Equation 4)
Px <P2 <P1
(In Equation 4, P1 represents the control pressure by the check mechanism 71A, and P2 represents the control pressure by the pressure control valve 72A)

  The hydrogen supply plate 75 is formed of, for example, a resin molded body in which a carbon material is blended, and also has a function as an anode side separator when a plurality of fuel cell systems are combined. Further, the hydrogen supply plate 75 is provided with a heat insulating layer 75A on the surface in contact with the hydrogen separation membrane 74 and on the back surface thereof, so that heat dissipation from the hydrogen supply plate 75 is suppressed. Thereby, the thermal efficiency can be improved and stable driving can be performed.

  The thermal conductivity λ of the heat insulating layer 75A is preferably 0.001 ≦ λ ≦ 1. The heat conductivity λ of the heat insulating layer 75A is defined by a Fourier heat conduction equation expressed by the equation (5). The lower the heat conductivity, the more heat radiation to the outside is suppressed and the energy efficiency of the entire fuel cell system is improved. . Furthermore, it is more preferable if the thermal conductivity λ is 0.1 or less.

(Equation 5)
λ (W / mK) = Thickness (m) / Rs (m ² K / W)
(In Equation 5, Rs represents thermal resistance.)

Examples of the constituent material of the heat insulating layer 75A include silicon oxide (SiO ₂ ), polyimide compounds, ceramic fibers, and porous ceramics.

The improvement in energy efficiency by the heat insulating layer 75A can be calculated from the thermal conductivity λ. For example, when the reforming part 70 is constituted by a casing made of aluminum (Al) having a surface area of 100 cm ² and a wall thickness of 1 mm, and the temperature of the reforming part 70 is 300 ° C., the thermal conductivity of aluminum is 236 (W / mK), and when operated at room temperature (23 ° C.) for 1 hr, the heat dissipated energy is expressed by Equation 6 and becomes 3067 Wh. On the other hand, when a heat insulating layer 75A having a thermal conductivity of 0.1 and a thickness of 1 mm is formed on the surface, the heat dissipation amount is suppressed to 1.3 Wh.

(Equation 6)
1 hr * 236 (W / mK) * 1 (mm) / (100 (cm ² ) * (300-23) (° C.)
= 3600 (s) * 236 ( W / mK) * 0.01 (m) / (0.01 (m 2) * 277 (K))
= 3067 Wh

  The hydrogen supply plate 75 may be provided with the humidification layer for hydrogen humidification described in the second embodiment as necessary, and the humidification water tank and the moisture supply path are attached to the humidification layer. May be provided separately.

  FIG. 17 illustrates a cross-sectional configuration of the power generation unit 10 illustrated in FIG. 12. The power generator 11 is disposed between the hydrogen supply plate 75 that functions as the anode electrode 12 and the cathode electrode 13. Between the hydrogen supply plate 75 and the power generator 11, and between the cathode 13 and the power generator 11, silicone rubber, styrene-butadiene copolymer rubber, soft polyvinyl chloride, vinylidene fluoride rubber, nitrile rubber, A sealing layer 14 made of ethylene propylene rubber or butyl rubber is provided. In FIG. 17, the heat insulating layer 75A of the hydrogen supply plate 75 is omitted.

  The cathode electrode 13 has, for example, a polygonal positive electrode flow path 13A as shown in FIG. 18 on the surface on the power generation body 11 side, and supplies oxygen to the power generation unit 10 through the positive electrode flow path 13A substantially evenly. Can be done. Further, the cathode electrode 13 also has a function as a cathode-side separator when a plurality of the power generation unit 10 and the reforming unit 70 shown in FIG. 12 are combined.

  FIG. 19 schematically shows an example of the appearance of the fuel cell system shown in FIG. In this fuel cell system, for example, four power generation units 10 and four reforming units 70 shown in FIG. 12 are sandwiched between the cathode current collector 100A and the anode current collector 100B, for example. The air supply pump 51 is disposed on the storage unit 20 and the cathode current collector 100A. On the side of the reforming unit 70, a control unit 110 configured by a system control board including the rectifier 40 and the like, sensors, and the like, and an auxiliary power source 60 are disposed. In FIG. 19, the temperature controller 90, the gas-liquid separator 52 (see FIG. 11) or the humidifying water tank are omitted. The number of power generation units 10 and reforming units 70 is not limited to four, and the arrangement relationship of each component is not limited to that shown in FIG.

  This fuel cell system can be manufactured, for example, as follows.

  First, a catalyst support layer 73A in which the above-described catalyst is supported on a porous material is produced. Next, a covering member 73C having a heater 73B and a check mechanism 71A and a pressure control valve 72A is prepared, and the catalyst support layer 73A is accommodated in the covering member 73C. Thereby, for example, the reforming reaction layer 73 having a width of 40 mm, a length of 110 mm, and a thickness of 2 mm is produced.

  Subsequently, the hydrogen separation membrane 74 made of the above-mentioned material, for example, having a width of 40 mm, a length of 110 mm, and a thickness of 100 μm, and the lead-out path 76 and the negative electrode flow path 12A as shown in FIG. A hydrogen supply plate 75 having a length of 150 mm and a thickness of 1 mm is prepared, and a reforming reaction layer 73, a hydrogen separation membrane 74, and a hydrogen supply plate 75 are laminated in this order, and are shown in FIGS. A reforming unit 70 is formed. The hydrogen supply plate 75 is provided with a heat insulating layer 75A made of the above-described material so that the heat conductivity λ of the heat insulating layer 75A satisfies 0.001 ≦ λ ≦ 1.

Further, for example, a power generation body 11 having a catalyst supporting area of 10 cm ² , a width of 40 mm, a length of 40 mm, and a thickness of 1 mm and a positive electrode channel 13A as shown in FIG. 18 is formed, for example, a width of 40 mm, a length of 40 mm, and a thickness. A cathode electrode 13 having a thickness of 1 mm is prepared, and the power generator 11 and the cathode electrode 13 are stacked in this order on the remaining region of the hydrogen supply plate 75, and the power generator 10 shown in FIGS. Form.

  Thereafter, four power generation units 10 and four reforming units 70 are stacked and sandwiched between the cathode current collector 100A and the anode current collector 100B, and the storage unit 20 and the cathode current collector are placed on the reforming unit 70. Air supply pumps 51 are respectively disposed on the body 100A. In addition, a control unit 110 configured by a system control board including the rectifier 40 (see FIG. 1), sensors, and the like, and an auxiliary power source 60 are disposed on the side of the reforming unit 70. Thus, the fuel cell system shown in FIG. 19 is completed.

  In this fuel cell system, the liquid fuel stored in the storage unit 20 is supplied to the reforming unit 70 by the fuel supply unit 30, and hydrogen is generated by the reaction of the liquid fuel. The generated hydrogen is supplied to the power generation unit 10 and power is generated by the reaction between hydrogen and oxygen. Here, the liquid fuel is vaporized by heat in the fuel supply unit 30, and is discharged as a jet flow by the expansion of the volume, and is supplied to the reforming unit 70. Therefore, the temperature drop of the reforming unit 70 due to the liquid fuel supply is small, the temperature in the reforming unit 70 is always maintained at a temperature at which the catalytic activity can be expressed, and stable reforming efficiency can be obtained over the entire reforming unit 70. .

  Further, the reforming section 70 is heated to a temperature of, for example, about 300 ° C. or higher in order to enhance the catalytic action, and the fuel expands in volume by vaporization. As a result, the internal pressure of the reforming unit 70 increases, and the internal pressure of the reforming unit 70 becomes higher than that of the power generation unit 10. Due to the pressure difference, as shown in FIG. It is separated by the membrane 74 and supplied to the power generation unit 10 via the outlet path 76. Further, the check mechanism 71 </ b> A and the pressure control valve 72 </ b> A control the internal pressure of the reforming 70 to be higher than that of the power generation unit 10, and hydrogen is stably supplied to the power generation unit 10.

  As described above, in the present embodiment, by controlling the internal pressure of the reforming unit 70 to be higher than that of the power generation unit 10, hydrogen is supplied to the power generation unit 10 using the pressure difference. Therefore, pumps and actuators that transport hydrogen can be reduced. Therefore, a small and stable fuel cell system capable of driving can be realized.

  In addition, the reforming unit 70 has a stacked structure of the reforming reaction layer 73, the hydrogen separation membrane 74, and the hydrogen supply plate 75, and the lead-out path 76 is provided on the surface of the hydrogen supply plate 75 in contact with the hydrogen separation membrane 74. The hydrogen generated in the reforming reaction layer 73 is separated by the hydrogen separation membrane 74 and moved to the outlet path 76, while the movement of by-products such as carbon dioxide to the outlet path 76 can be suppressed. Therefore, the hydrogen partial pressure control can be facilitated and the efficiency of the power generation unit 10 can be increased.

  Furthermore, since the power generation unit 10 is integrated with the hydrogen supply plate 75 so as to face the lead-out path 76 in parallel with the hydrogen separation membrane 74, the reforming unit 70 and the power generation unit 10 can be combined and integrated. Therefore, it is possible to realize a fuel cell system with a simple structure and further reduced in size.

  In addition, since the portion of the lead-out path 76 corresponding to the power generation unit 10 is the negative-electrode channel 12A that can supply hydrogen to the power generation unit 10 substantially evenly, the lead-out path 76 can be simplified. Therefore, heat loss at the time of hydrogen transfer can be reduced, and the thermal efficiency of the entire fuel cell system can be improved.

  Furthermore, in the reforming unit 70, the check mechanism 71A is provided at the inlet 71 for introducing the liquid fuel, so that it is prevented that the fuel flows back from the inlet 71 even if volumetric expansion occurs due to vaporization. The internal pressure of the reforming unit 70 can be kept high. Therefore, hydrogen can be sent to the power generation unit 10 by effectively using the increase in internal pressure due to the reaction of the fuel.

  In addition, in the reforming unit 70, the pressure control valve 72A is provided at the discharge port 72 for discharging the by-product due to the reaction of the liquid fuel, so that the gas flows backward from the introduction port 71 depending on the operating conditions. Etc., and stable fuel supply can be performed.

  Furthermore, since the heat insulating layer 75A is provided on the surface of the hydrogen supply plate 75, the heat radiation amount can be reduced, the energy conversion efficiency of the entire fuel cell system can be increased, and stable driving can be performed.

  Furthermore, specific examples of the present invention will be described.

(Example 1-1)
The fuel cell system shown in FIG. 1 was produced in the same manner as in the first embodiment. First, the power generation unit 10 having an effective area of 5 × 5 cm ² and a theoretical methanol usage calculated from the amount of supported catalyst of 3.6 × 10 ⁻³ cm ³ / min was formed.

Next, the supply head portions 31 by a thermal ink jet method having a discharge amount of 5 pL and a discharge frequency of 30 kHz were arranged at 4 pieces / cm ² to form a fuel supply portion 30 having a size of 5 × 5 cm ² . That is, in this embodiment, the maximum liquid fuel consumption Q1 in the power generation unit 10 and the maximum liquid fuel discharge amount Q2 in the fuel supply unit 30 are set to satisfy Q1 ≦ Q2. The fuel supply unit 30 is disposed on the anode electrode 12 side of the power generation unit 10.

Subsequently, a 50 mol% aqueous methanol solution was stored as the liquid fuel, and a storage unit 20 having a capacity of 100 cc (inner diameter: 4 × 5 × 5 cm ³ ) was prepared. A bag 23B made of polyethylene / polypropylene as shown in FIG. 6 was inserted into the storage unit 20 to form a pressurizing chamber 23, and a pressure control valve 23D was provided at the gas inlet 23C. Thereby, the pressure control mechanism 22 was formed in the storage unit 20. The internal pressure of the pressurizing chamber 23 during operation was set to 1.5 atm.

  After that, an air supply pump 51 having a maximum discharge amount of 1 NL / min was connected to the cathode 11 side of the power generation unit 10 and the pressure control mechanism 22. The air supply pump 51 is provided with a back pressure control valve (not shown), and is set so that a back pressure of +0.3 to 0.5 atm is applied to the air supply path 51A when stopped. Furthermore, the rectifier 40 and the gas-liquid separator 52 were connected to the power generation unit 10, and commercially available lithium ion secondary batteries (US18650, 3) were disposed as the auxiliary power source 60. Thus, the fuel cell system shown in FIG. 1 was formed.

With respect to the obtained fuel cell system, when the temperature of the power generation unit 10 was set to 80 ° C. and the maximum output per power generation body 11 was examined, it was 2.6 W (110 mW / cm ² ).

  As described above, in Example 1-1, the liquid fuel is vaporized by heat, and the liquid supply is supplied as a jet by the expansion of the volume, that is, the fuel supply unit 30 to be supplied to the power generation unit 10 by the thermal ink jet method. It was confirmed that an output could be obtained even when applied to a battery system.

(Example 1-2)
A fuel cell system was fabricated in the same manner as in Example 1-1, except that the fuel supply unit 30 in which the supply head units 31 were arranged at 2 pieces / cm ² was used. In other words, in the present embodiment, the maximum discharge amount Q2 of the liquid fuel in the fuel supply unit 30 is reduced to one-half that of the embodiment 1-1 so that Q1> Q2. Also for this fuel cell system, when the maximum output per generator 11 was examined in the same manner as in Example 1-1, it was 1.35 W (52 mW / cm ² ).

  As described above, in Example 1-2 in which Q1> Q2, the maximum output was lower than that in Example 1-1 in which Q1 ≦ Q2, and only about a half was obtained. That is, it was found that the maximum output can be increased if the maximum consumption Q1 of liquid fuel in the power generation unit 10 and the maximum discharge amount Q2 of liquid fuel in the fuel supply unit 30 satisfy Q1 ≦ Q2. .

(Example 2-1)
The fuel cell system shown in FIG. 7 was produced in the same manner as in the second embodiment. First, a reforming reaction layer containing Cu / ZnO / Al ₂ O ₃ containing copper, zinc and aluminum as a catalyst in a molar ratio of copper: zinc: aluminum = 6: 3: 1 is formed on a substrate made of copper. The reforming part 70 having a reforming efficiency a of 90% was formed.

In addition, a power generation body 11 having a catalyst supporting area of 10 cm ² , a width of 40 mm, a length of 40 mm, and a thickness of 1 mm, and an anode electrode 12 and a cathode electrode 13 made of the above-mentioned materials and having a width of 40 mm, a length of 40 mm, and a thickness of 1 mm are prepared. Then, the anode electrode 12, the power generation body 11, and the cathode electrode 13 were laminated in this order to form the power generation unit 10. The theoretical hydrogen usage calculated from the amount of supported catalyst was 3.0 × 10 ⁻³ cm ³ / min in terms of the supplied liquid fuel.

Next, the supply head portions 31 by a thermal ink jet method with a discharge amount of 5.5 pL and a discharge frequency of 30 kHz were arranged at 4 pieces / cm ² to form the fuel supply portion 30. That is, in this embodiment, Q1 ≦ Q2 * a. The fuel supply unit 30 is disposed on the reforming reaction layer side of the reforming unit 70.

Subsequently, a 50 mol% aqueous methanol solution was stored as a liquid fuel, and a storage unit 20 having a capacity of 100 cc (inner diameter: 4 × 5 × 5 cm ³ ) was prepared. A bag 23B made of polyethylene / polypropylene as shown in FIG. 6 was inserted into the storage unit 20 to form a pressurizing chamber 23, and a pressure control valve 23D was provided at the gas inlet 23C. Thereby, the pressure control mechanism 22 was formed in the storage unit 20. The internal pressure of the pressurizing chamber 23 during operation was set to 1.5 atm.

  After that, an air supply pump 51 having a maximum discharge amount of 1 NL / min was connected to the cathode 11 side of the power generation unit 10 and the pressure control mechanism 22. Furthermore, the rectifier 40 and the gas-liquid separator 52 are connected to the power generation unit 10, and commercially available lithium ion secondary batteries (US18650, 3) are disposed as the auxiliary power source 60. Although not shown in FIG. 7, a humidifying water tank having a capacity of 100 cc was disposed. Thus, the fuel cell system shown in FIG. 7 was completed.

With respect to the obtained fuel cell system, when the temperature of the reforming unit 70 was set to 300 ° C. and the temperature of the power generation unit 10 was set to 80 ° C., the maximum output per power generator 11 was examined, and the result was 4.0 W (400 mW / cm ² ). It was.

  As described above, in Example 2-1, the liquid fuel is vaporized by heat, and the fuel supply unit 30 supplied to the power generation unit 10 by the thermal ink jet method as the liquid fuel is jetted by the expansion of the volume. It was confirmed that the output could be obtained even when applied to the type fuel cell system.

(Examples 2-2 and 2-3)
In Example 2-2, the fuel supply unit 30 in which the supply head units 31 are arranged at 2 pieces / cm ² is used, and in Example 2-3, the fuel supply unit 30 is configured by using the supply head unit 31 having a discharge amount of 4 pL. Except for this, a fuel cell system was fabricated in the same manner as in Example 2-1. That is, in Examples 2-2 and 2-3, both were set to satisfy Q1> Q2 * a (a is the reforming efficiency). Regarding these fuel cell systems, when the maximum output per power generator 11 was examined in the same manner as in Example 2-1, 2.0 W (200 mW / cm ² ) was obtained in Example 2-2, and Example 2-3. Then, it was 3.1 W (310 mW / cm ² ).

  Thus, in Examples 2-2 and 2-3 in which Q1> Q2 * a, the maximum output was lower than that in Example 2-1 in which Q1 ≦ Q2 * a. That is, if the maximum consumption Q1 of liquid fuel in the power generation unit 10 and the maximum discharge amount Q2 of liquid fuel in the fuel supply unit 30 satisfy Q1 ≦ Q2 * a, the maximum output can be increased. I understood.

  The present invention has been described with reference to the embodiments and examples. However, the present invention is not limited to the above embodiments and examples, and various modifications can be made. For example, in the above-described embodiments and examples, the configurations of the power generation unit 10, the storage unit 20, the fuel supply unit 30, and the reforming unit 70 have been specifically described, but may be configured by other structures or other materials. May be.

  Further, for example, in the third embodiment, as shown in FIG. 20, for example, air can be supplied as the pressurizing gas through the air supply path 51 </ b> A branched from the air supply pump 51. Thereby, air can be supplied to both the power generation unit 10 and the pressure control mechanism 22 by using a common air supply path, and further miniaturization can be achieved.

  Furthermore, in the said embodiment and Example, although the supply of the air to the electric power generation part 10 was forcedly performed using the air supply pump 51, it is good also as natural ventilation. Further, oxygen or a gas containing oxygen may be supplied instead of air.

  In addition, in the third embodiment, a stacked fuel cell system in which a plurality of power generation units 10 and reforming units 70 are stacked as illustrated in FIG. 19 has been described. However, the third embodiment is a simple example. The present invention can also be applied to a cell type.

1 is a block diagram illustrating an overall configuration of a fuel cell system according to a first embodiment of the present invention. It is a figure showing the structure of the fuel supply part shown in FIG. It is sectional drawing showing the structure of the supply head part shown in FIG. It is a block diagram showing the other structural example of the fuel cell system shown in FIG. It is sectional drawing showing an example of an internal structure of the storage part shown in FIG. It is sectional drawing showing the other example of the internal structure of the storage part shown in FIG. It is a block diagram showing the whole structure of the fuel cell system which concerns on the 2nd Embodiment of this invention. It is a block diagram showing the other structural example of the fuel cell system shown in FIG. FIG. 8 is a perspective view illustrating an arrangement example of a power generation unit, a reforming unit, and a storage unit illustrated in FIG. 7. FIG. 8 is a perspective view illustrating another arrangement example of the power generation unit, the reforming unit, and the storage unit illustrated in FIG. 7. It is a block diagram showing the whole structure of the fuel cell system which concerns on the 3rd Embodiment of this invention. It is a perspective view showing the structure of the electric power generation part and modification | reformation part which were shown in FIG. It is sectional drawing which represents typically the movement path | route of hydrogen in the electric power generation part and reforming part shown in FIG. It is a top view showing the structure which looked at the hydrogen supply board shown in FIG. 12 from the outlet path side. It is sectional drawing showing the structure of the modification part shown in FIG. FIG. 16 is a plan view illustrating a configuration of the catalyst support layer illustrated in FIG. 15 as viewed from the fuel supply path side. It is sectional drawing showing the structure of the electric power generation part shown in FIG. FIG. 18 is a plan view illustrating a configuration of the cathode electrode illustrated in FIG. 17 as viewed from the positive electrode channel side. It is the perspective view which represented typically an example of the external appearance of the fuel cell system shown in FIG. FIG. 12 is a block diagram illustrating another configuration example of the fuel cell system illustrated in FIG. 11. It is a block diagram showing an example of the conventional fuel reforming type fuel cell system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Electric power generation part, 11 ... Electric power generation body, 12 ... Anode electrode, 12A ... Negative electrode flow path, 13 ... Cathode electrode, 13A ... Positive electrode flow path, 14 ... Sealing layer, 20 ... Storage part, 21 ... Fuel tank chamber, DESCRIPTION OF SYMBOLS 22 ... Pressure control mechanism, 22A ... Exhaust supply path, 23 ... Pressurization chamber, 23A ... Movable wall, 23B ... Bag body, 30 ... Fuel supply part, 31 ... Supply head part, 32 ... Liquid chamber, 33 ... Orifice formation board 33A ... partition wall, 34 ... flow path, 35 ... heater, 36 ... nozzle, 37 ... heating control circuit, 38 ... vaporized fuel, 39 ... jet, 40 ... rectifier, 51 ... air supply pump, 51A ... air supply path, 52 ... Gas-liquid separator, 60 ... Auxiliary power supply, 70 ... Reformer, 71 ... Inlet port, 71A ... Check mechanism, 72 ... Discharge port, 72A ... Pressure control valve, 73 ... Reforming reaction layer, 74 ... Hydrogen Separation membrane, 75 ... hydrogen supply plate, 75A ... heat insulation layer, 76 Outlet passage

Claims (22)

A power generation unit that generates power by receiving supply of liquid fuel and air;
A reservoir for storing the liquid fuel;
A fuel cell system comprising: a fuel supply unit that vaporizes the liquid fuel supplied from the storage unit by heat and supplies the liquid fuel to the power generation unit as a jet by expansion of its volume.   The fuel cell system according to claim 1, wherein the storage unit includes a fuel tank chamber that stores the liquid fuel, and a pressure control mechanism that controls an internal pressure of the fuel tank chamber.   The fuel cell system according to claim 2, further comprising an air supply pump that supplies air to the power generation unit and the pressure control mechanism.   The fuel cell system according to claim 2, further comprising an exhaust supply path for supplying exhaust from the power generation unit to the pressure control mechanism. 2. The fuel cell system according to claim 1, wherein a maximum consumption amount Q1 of liquid fuel in the power generation unit and a maximum discharge amount Q2 of liquid fuel in the fuel supply unit satisfy Formula 1. 3.
(Equation 1)
Q1 ≦ Q2   2. The fuel cell system according to claim 1, wherein an aqueous methanol solution is used as the liquid fuel. A power generation unit that generates power by reaction of hydrogen and oxygen;
A reforming unit that reacts liquid fuel to generate hydrogen, and supplies the generated hydrogen to the power generation unit;
A reservoir for storing the liquid fuel;
A fuel cell system comprising: a fuel supply unit that vaporizes the liquid fuel supplied from the storage unit by heat and supplies the liquid fuel as a jet to the reforming unit by expansion of its volume.   8. The fuel cell system according to claim 7, wherein the storage unit includes a fuel tank chamber that stores the liquid fuel, and a pressure control mechanism that controls an internal pressure of the fuel tank chamber.   The fuel cell system according to claim 8, further comprising an air supply pump that supplies air to the power generation unit and the pressure control mechanism.   The fuel cell system according to claim 8, further comprising an exhaust supply path that supplies exhaust from the power generation unit to the pressure control mechanism. 8. The fuel cell system according to claim 7, wherein the maximum consumption amount Q1 of liquid fuel in the power generation unit and the maximum discharge amount Q2 of liquid fuel in the fuel supply unit satisfy Formula 2.
(Equation 2)
Q1 ≦ Q2 * a
(In Equation 2, a represents the reforming efficiency in the reforming section.)   8. The fuel cell system according to claim 7, wherein an aqueous methanol solution is used as the liquid fuel.   The fuel according to claim 7, wherein the reforming unit controls the internal pressure to be higher than that of the power generation unit, and supplies hydrogen generated using the pressure difference to the power generation unit. Battery system. The reformer is
A reforming reaction layer that reacts the liquid fuel to generate hydrogen;
A hydrogen separation membrane that is disposed in contact with the reforming reaction layer and selectively permeates hydrogen generated in the reforming reaction layer;
14. A hydrogen supply plate that is in contact with the hydrogen separation membrane and has a lead-out path on the hydrogen separation membrane side, and supplies hydrogen that has passed through the hydrogen separation membrane to the power generation unit. Fuel cell system.   The fuel cell system according to claim 14, wherein the power generation unit is integrated with the hydrogen supply plate so as to face the lead-out path in parallel with the hydrogen separation membrane.   The fuel cell system according to claim 15, wherein a portion of the lead-out path corresponding to the power generation unit is a negative electrode channel capable of supplying hydrogen to the power generation unit substantially evenly.   The fuel cell system according to claim 13, wherein the reforming unit includes an introduction port for introducing the liquid fuel and a check mechanism provided in the introduction port.   18. The fuel cell system according to claim 17, wherein the reforming unit includes a discharge port for discharging a by-product due to the reaction of the liquid fuel, and a pressure control valve provided in the discharge port. . 19. The fuel cell system according to claim 18, wherein the control pressure P1 by the check mechanism and the control pressure P2 by the pressure control valve satisfy Equation 3.
(Equation 3)
P2 <P1 19. The fuel cell system according to claim 18, wherein the pressure Px at which the hydrogen separation membrane selectively permeates hydrogen satisfies Formula 4.
(Equation 4)
Px <P2 <P1
(In Equation 4, P1 represents the control pressure by the check mechanism, and P2 represents the control pressure by the pressure control valve.)   The fuel cell system according to claim 14, wherein the hydrogen supply plate has a heat insulating layer on a surface thereof. The fuel cell system according to claim 21, wherein the thermal conductivity λ of the heat insulating layer is 0.001 ≦ λ ≦ 1.

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