JP2005100864A - Measurement method of alcohol concentration, measurement device of alcohol concentration, and fuel cell system including the device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect alcohol concentration of an alcohol gas by a simple structure. <P>SOLUTION: This fuel cell system 660 includes a solid polyelectrolyte membrane 114, a fuel cell main body 100 including a fuel electrode 102 and an oxidizer electrode 108 arranged at the solid polyelectrolyte membrane 114, a fuel housing part 664 to house an organic liquid fuel 124a, and a polymer membrane 665 having proton conductivity and being installed at a fuel electrode tank 662, and a concentration measurement part (first electrode terminal 666, second electrode terminal 667, and concentration detecting part 670) to detect the alcohol concentration of a fuel gas 124b in the fuel electrode tank 662 by a method based on changes in the proton conductivity of the polymer membrane 665. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an alcohol concentration measurement method for alcohol gas, an alcohol concentration measurement device, and a fuel cell system including the device.

  In recent years, fuel cells with high power generation efficiency and extremely low generation of harmful gases have attracted attention and are actively researched and developed. Some fuel cells use a gas such as hydrogen as a fuel, and others use a liquid such as methanol. Since a fuel cell using gaseous fuel needs to be equipped with a fuel cylinder or the like, there is a limit to downsizing. For this reason, the use of a direct methanol fuel cell that does not require a reformer or the like is considered promising as a power source for small portable devices such as mobile phones and notebook computers.

  In the case of a direct methanol fuel cell, electrochemical reactions occurring at the fuel electrode and the oxidant electrode are represented by the following reaction formulas (1) and (2), respectively.

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

Oxidant electrode: O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (2)

  As represented by the reaction formula (1), carbon dioxide is generated at the fuel electrode. In order to generate electricity smoothly, it is necessary to efficiently supply methanol to the surface of the metal catalyst and actively cause the reaction of the above reaction formula (1). However, the supply of fuel in a conventional direct methanol fuel cell has been performed by immersing the fuel electrode with an aqueous methanol solution. Therefore, the carbon dioxide generated by the reaction formula (1) stays in the fuel electrode to generate bubbles, and the catalytic reaction in the fuel electrode may be inhibited. As a result, stable output may not be obtained.

By the way, the following Patent Document 1 discloses a reformer for a fuel cell including an ultrasonic atomizer. In this technique, fuel is atomized by an ultrasonic atomizer and supplied to a reformer that converts the fuel into a gas rich in hydrogen. Therefore, in the fuel cell using the fuel cell reformer of this technology, the carbon dioxide bubbles do not stay as described above. However, there is a limit to reducing the size and weight of a fuel cell having such a fuel cell reformer.
JP-A-11-79703 JP 2001-102070 A

  Therefore, a technology for supplying a fuel gas obtained by gasifying an organic liquid fuel such as methanol to the fuel electrode has been developed by the present applicant. By using the fuel gas, carbon dioxide generated at the fuel electrode can be efficiently removed from the electrode surface, so that carbon dioxide can be prevented from staying on the electrode surface, and power generation efficiency can be improved. .

  Further, by using the fuel gas, it is possible to reduce the problem of crossover, which is a phenomenon in which the methanol aqueous solution permeates the solid polymer electrolyte membrane and reaches the oxidant electrode side. Thereby, the fall of the power generation efficiency by the potential of an oxidant electrode falling can be reduced. Furthermore, by using the fuel gas, even if the alcohol concentration in the fuel gas is increased, the problem of crossover can be reduced. Therefore, the alcohol concentration in the gas can be increased, further improving the power generation efficiency. Can be improved.

  By using the fuel gas, the power generation efficiency can be improved in this way. Therefore, a sufficient output can be obtained even if the container of the fuel electrode tank is made small, and the fuel cell system can be downsized.

  Conventionally, when an organic liquid fuel is used as a fuel to be supplied to the fuel electrode, there is a problem of crossover. Therefore, the concentration of the organic liquid fuel to be supplied to the fuel electrode needs to be constant or lower. It was done to control the concentration. On the other hand, as described above, when the fuel gas is used as the fuel, such a problem does not occur. Therefore, there has been no idea of measuring or controlling the concentration of the fuel gas supplied to the fuel electrode.

  However, according to the study of the present inventor, in order to keep the output of the fuel cell stable and to obtain an efficient output, even when the fuel gas is used, the concentration of the fuel gas is within an appropriate range. It has been found necessary to do.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an alcohol concentration measuring device capable of detecting the alcohol concentration of fuel gas with a simple structure, a fuel cell system including the device, and an alcohol. It is to provide a concentration measurement method.

  According to the present invention, there is provided a fuel cell system that uses alcohol gas as a fuel, and a fuel cell main body including a solid polymer electrolyte membrane, and a fuel electrode and an oxidizer electrode disposed on the solid polymer electrolyte membrane; There is provided a fuel cell system comprising a container containing alcohol gas, and a concentration detector for detecting the alcohol concentration of the alcohol gas in the container.

  Here, the fuel cell main body may be a direct type that directly supplies liquid fuel to the fuel electrode. The container containing the alcohol gas includes a fuel electrode tank provided in the fuel electrode of the fuel cell main body, a buffer tank for storing fuel supplied to the fuel electrode tank, a cartridge, or a pipe connecting these.

  By setting it as such a structure, the density | concentration of the alcohol gas supplied to a fuel electrode can be maintained in an appropriate range, and the output of a fuel cell system can be stabilized. In addition, the concentration of the alcohol gas can be set within a range where the electrode reaction can be performed efficiently.

  In the fuel cell system of the present invention, the concentration detector has proton conductivity and can include a polymer membrane provided in the container. Based on the change in proton conductivity of the polymer membrane, the concentration detector The alcohol concentration of the alcohol gas can be detected.

  The polymer membrane can be composed of a material whose proton conductivity changes depending on the alcohol concentration in the alcohol gas in the container. As the polymer film, a material containing a proton acid group can be used. The polymer film can also be crosslinked.

  According to the fuel cell system of the present invention, the alcohol concentration of the alcohol gas can be detected with a simple configuration.

  In the fuel cell system of the present invention, the concentration detection unit includes a pair of electrode terminals disposed on the polymer film, a resistance measurement unit that measures a resistance value between the electrode terminals, and a resistance value measured by the resistance measurement unit. A concentration calculation unit that calculates an alcohol concentration of the alcohol gas based on the alcohol gas.

  Here, since the polymer membrane is made of a material whose proton conductivity changes according to the alcohol concentration, when a current is passed between the electrode terminals via the polymer membrane, the polymer membrane depends on the alcohol concentration of the alcohol gas. The resistance value between the electrode terminals changes. The concentration detection unit can hold reference data indicating a correspondence relationship between the resistance value between the electrode terminals and the alcohol concentration, and the concentration calculation unit can calculate the alcohol concentration of the alcohol gas based on the reference data. .

  Here, the concentration detection unit may include three or more electrode terminals, and may include, for example, four electrode terminals. In this case, one pair of electrode terminals can be used for current measurement, and the other pair of electrode terminals can be used for voltage measurement. The electrode terminal can be provided on the surface of the polymer film, but may be provided in the polymer film. Moreover, although an electrode terminal can also be provided in alcohol gas, it can also be set as the structure which does not contact alcohol gas directly. By making the electrode terminal not in direct contact with the alcohol gas, it is possible to prevent the electrode terminal from being corroded by the alcohol gas. Thereby, an electrode terminal can be kept stable. The electrode terminal can be made of any material as long as it has conductivity. The electrode terminal can be made of, for example, gold, silver, platinum, aluminum, stainless steel, or the like.

  In the fuel cell system of the present invention, in the concentration detection unit, the electrode terminal can be provided outside the container. Further, the concentration detection unit can have a hydrophobic film covering the electrode terminals.

  In the fuel cell system of the present invention, the solid polymer electrolyte membrane can be provided in a container, and a part of the solid polymer electrolyte membrane can be used as the polymer membrane. In this case, in the solid polymer electrolyte membrane, an electrode terminal can be provided in a region where the catalyst layer is not provided.

  The fuel cell system of the present invention can include a plurality of polymer membranes having different proton conductivities with respect to temperature or pH, and the concentration detection unit is based on a change in proton conductivity of each of the plurality of polymer membranes. The alcohol concentration of the alcohol gas can be detected in consideration of the temperature or pH of the alcohol gas.

  The fuel cell system of the present invention can further include gasification means for gasifying a liquid fuel containing alcohol, and the gasified alcohol gas can be supplied to the container. Here, the alcohol gas may be vaporized or atomized liquid fuel. As a method for gasifying the liquid fuel, heating by a heating device, a method for bubbling a liquid with a carrier gas such as nitrogen, a method for introducing and pressurizing a gas into a container containing the liquid fuel, and a method using an atomizing means Can be used. As the atomizing means, an ultrasonic vibration type atomizing device such as a piezoelectric vibrator can be used.

  In this way, by supplying gasified fuel to the fuel electrode, the fuel electrode is not filled with liquid, unlike a conventional fuel cell that directly supplies liquid fuel to the fuel electrode. As a result, the carbon dioxide produced at the fuel electrode separates from the fuel electrode without forming bubbles, so that the electrochemical reaction at the fuel electrode proceeds smoothly and a stable output is obtained.

  The fuel cell system of the present invention may further include a control unit that controls driving of the gasification means in accordance with the alcohol concentration detected by the concentration detection unit.

  The fuel cell system of the present invention can further include a cartridge configured to be detachable from the fuel cell main body and accommodate liquid fuel, and the gasification means can gasify the liquid fuel accommodated in the cartridge. it can.

  The fuel cell system of the present invention can further include a plurality of liquid fuel storage portions that respectively store liquid fuels having different alcohol concentrations, and the gasification means can gasify the liquid fuel for each liquid fuel. .

  In the fuel cell system of the present invention, the liquid fuel container may be a cartridge configured to be removable from the fuel cell main body.

  The fuel cell system of the present invention may further include a temperature sensor that measures the temperature in the container, and the concentration detection unit corrects the alcohol concentration of the alcohol gas in the container according to the temperature measured by the temperature sensor. Can do.

  The fuel cell system of the present invention may further include a pH measurement unit that measures the pH in the container, and the concentration detection unit corrects the alcohol concentration of the alcohol gas in the container according to the pH measured by the pH measurement unit. can do.

  The fuel cell system of the present invention presents a warning to the warning presenting unit when the alcohol concentration of the alcohol gas in the container detected by the concentration detecting unit and the concentration detecting unit is outside a predetermined range. And a control unit for instructing. For example, the control unit can instruct the warning presenting unit to present a warning when the alcohol concentration of the alcohol gas in the container becomes a predetermined value or less. In this way, it is possible to notify the user who is using the electronic device incorporating the fuel cell system of the present invention that the fuel in the container has run out.

  In the fuel cell system of the present invention, a part of the wall forming the container may be a membrane that allows carbon dioxide generated at the fuel electrode to permeate.

  According to the present invention, there is provided a portable device in which the fuel cell system having the above configuration is mounted.

  According to the present invention, there is provided a portable personal computer equipped with the fuel cell system having the above configuration.

  According to the present invention, there is provided an apparatus for measuring alcohol concentration, which has proton conductivity and a polymer membrane whose proton conductivity changes according to the alcohol concentration in the gas when in contact with a gas containing alcohol. There is provided an alcohol concentration measurement apparatus comprising: a concentration detection unit that detects an alcohol concentration in a gas based on a change in proton conductivity of a polymer membrane. The alcohol concentration measuring device can be used to measure the concentration of fuel in the fuel cell system as described above. For example, the alcohol concentration measuring device is used to measure the alcohol concentration in the environment or the alcohol concentration in human breath. You can also.

  In the alcohol concentration measurement apparatus of the present invention, the concentration detection unit includes a pair of electrode terminals disposed on the polymer film, a resistance measurement unit that measures a resistance value between the electrode terminals, and a resistance measured by the conductivity measurement unit. And a concentration calculator that converts the value into an alcohol concentration in the gas.

  According to the present invention, there is provided a method for measuring an alcohol concentration, the step of introducing a polymer film having proton conductivity into a container containing an alcohol gas to be measured, and detecting a change in proton conductivity of the polymer film. There is provided a method for measuring an alcohol concentration, comprising: a step; and a step of detecting an alcohol concentration of an alcohol gas based on a change in proton conductivity.

  In the alcohol concentration measurement method of the present invention, the step of detecting a change in proton conductivity can include a step of measuring a resistance value between a pair of electrode terminals disposed on the polymer membrane, and the alcohol concentration is determined. The step of detecting can include a step of calculating the alcohol concentration of the alcohol gas based on the resistance value.

  It should be noted that any combination of the above-described constituent elements, and those in which constituent elements and expressions of the present invention are mutually replaced between methods, apparatuses, and systems are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the alcohol concentration measuring apparatus which can detect alcohol concentration with a simple structure, the fuel cell system containing the said apparatus, and the alcohol concentration measuring method are provided.

  The application of the fuel cell system described in the following embodiments is not particularly limited. For example, a portable personal computer such as a mobile phone or a notebook type, a PDA (Personal Digital Assistant), various cameras, a navigation system, a portable music player, etc. Appropriately used for small electrical equipment.

(First embodiment)
FIG. 1 is a diagram showing an example of the configuration of the fuel cell system according to the first embodiment of the present invention.
The fuel cell system 660 generates electricity by gasifying the organic liquid fuel and supplying the gasified fuel to the fuel electrode. As the organic liquid fuel, methanol, ethanol, dimethyl ether, or other alcohols can be used. The organic liquid fuel can be an aqueous solution.

  The fuel cell system 660 includes a fuel cell main body 100, a fuel electrode tank 662, a sensor 668, a concentration measuring unit 670, a control unit 672, a fuel supply processing unit 674, a fuel storage unit 676, and a warning presenting unit 680. Including.

  The fuel cell main body 100 includes a solid polymer electrolyte membrane 114, and a fuel electrode 102 and an oxidant electrode 108 disposed on the solid polymer electrolyte membrane 114. As the oxidant supplied to the oxidant electrode 108, air can be normally used, but oxygen gas may be supplied. The detailed configuration of the fuel cell main body 100 will be described later.

In the present embodiment, the fuel storage unit 676 stores the organic liquid fuel 124a.
The fuel supply processing unit 674 includes gasification means for gasifying the organic liquid fuel 124 a stored in the fuel storage unit 676. The fuel supply processing unit 674 performs a process of supplying the fuel gas 124 b gasified by the gasification means to the fuel electrode tank 662. The detailed configuration of the fuel supply processing unit 674 will be described later.

  A sensor 668 is provided in the fuel electrode tank 662. The sensor 668 is used to detect the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662. The sensor 668 includes a polymer film 665, a first electrode terminal 666, and a second electrode terminal 667. The polymer film 665 is a polymer film having proton conductivity. The polymer film 665 is made of a material whose proton conductivity changes according to the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662. The fuel cell system 660 in the present embodiment can detect the methanol concentration of the fuel gas 124b in the fuel electrode tank 662 based on the change in proton conductivity of the polymer membrane 665.

The polymer membrane 665 can be made of any material as long as the proton conductivity changes according to the alcohol concentration of the fuel gas 124b. For example, the polymer membrane 665 can be made of the solid polymer electrolyte membrane 114 of the fuel cell main body 100. It can be comprised with the material similar to. As such a material,
An organic polymer having a polar group such as a strong acid group such as a sulfone group, a phosphoric acid group, a phosphone group or a phosphine group, or a weak acid group such as a carboxyl group is preferably used. As these organic polymers,
Aromatic-containing polymers such as sulfonated poly (4-phenoxybenzoyl-1,4-phenylene), alkylsulfonated polybenzimidazole;
Copolymers such as a polystyrene-containing sulfonic acid copolymer, a polyvinyl sulfonic acid copolymer, a crosslinked alkyl sulfonic acid derivative, a fluorine-containing polymer composed of a fluororesin skeleton and a sulfonic acid;
A copolymer obtained by copolymerizing acrylamides such as acrylamide-2-methylpropane sulfonic acid and acrylates such as n-butyl methacrylate;
Sulfone group-containing perfluorocarbon (Nafion (registered trademark, manufactured by DuPont), Aciplex (manufactured by Asahi Kasei));
Carboxyl group-containing perfluorocarbon (Flemion (registered trademark) S membrane (Asahi Glass Co., Ltd.));
Aromatic polyether, polyphenylene sulfide, polyimide, polyphosphazene, trifluorostyrene copolymer (BAM3G, manufactured by Ballard);
Etc. are exemplified.

  In addition, a crosslinkable substituent such as a vinyl group, an epoxy group, an acrylic group, a methacryl group, a cinnamoyl group, a methylol group, an azide group, or a naphthoquinonediazide group is appropriately introduced into the above polymer. A polymer crosslinked by irradiation with radiation, UV, electron beam or the like in the melted state as it is can also be used.

  The first electrode terminal 666 and the second electrode terminal 667 are provided on the surface of the polymer film 665 or in the polymer film 665 so as to be separated from each other. Here, since the polymer film 665 is made of a material whose proton conductivity changes according to the alcohol concentration, the polymer film 665 is interposed between the first electrode terminal 666 and the second electrode terminal 667. When the current flows, the resistance value between the first electrode terminal 666 and the second electrode terminal 667 changes according to the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662. The concentration measuring unit 670 measures the alcohol concentration of the fuel gas 124 b in the fuel electrode tank 662 based on the resistance value between the first electrode terminal 666 and the second electrode terminal 667. The detailed configuration of the concentration measuring unit 670 will be described later.

FIG. 2 shows the sensor 668 in detail.
2A is a diagram illustrating a surface of the sensor 668 on which the first electrode terminal 666 and the second electrode terminal 667 are provided, and FIG. 2B is a side view of FIG. 2A. The first electrode terminal 666 and the second electrode terminal 667 can be made of any material as long as it is stably present in the fuel gas 124b and has conductivity. The first electrode terminal 666 and the second electrode terminal 667 can be attached to the polymer film 665 with a conductive paste. As the conductive paste, a polymer paste containing a metal such as gold or silver, or a polymer paste such as acrylamide having a conductive property can be used. The first electrode terminal 666 and the second electrode terminal 667 are electrically connected to the concentration measuring unit 670 shown in FIG. 1 through the wiring 710a and the wiring 710b, respectively.

  FIG. 3 is a diagram illustrating another example of the sensor 668. The sensor 668 may have a configuration in which the surfaces of the first electrode terminal 666 and the second electrode terminal 667 are covered with a hydrophobic film 720 such as Teflon (registered trademark). In this way, even when the sensor 668 is introduced into the fuel electrode tank 662, the first electrode terminal 666 and the second electrode terminal 667 are not in direct contact with the fuel gas 124b in the fuel electrode tank 662. . Therefore, it is possible to prevent the first electrode terminal 666 and the second electrode terminal 667 from being corroded by the fuel gas 124b. Thereby, the 1st electrode terminal 666 and the 2nd electrode terminal 667 can be kept stable.

  FIG. 4 is a diagram illustrating another example of the sensor 668. As shown in FIG. 4A, the first electrode terminal 666 and the second electrode terminal 667 can be formed by winding a wiring 710a and a wiring 710b around a polymer film 665. Further, as shown in FIG. 4B, the wiring 710a and the wiring 710b are penetrated in the thickness direction of the polymer film 665, and the first electrode terminal 666 and the portion through which the wiring 710a and the wiring 710b penetrate is used as a fastening portion. The second electrode terminal 667 can also be formed.

  FIG. 5 is a diagram illustrating still another example of the sensor 668. As shown in FIG. 5A, the first electrode terminal 666 and the second electrode terminal 667 are configured by fixing the wiring 710a and the wiring 710b on the polymer film 665 with a conductive paste 711, respectively. You can also. As the conductive paste, as described above, a polymer paste containing a metal such as gold or silver, or a polymer paste such as acrylamide having a conductive property can be used. FIG. 5B is a side view of the sensor 668 shown in FIG. Note that also in the first electrode terminal 666 and the second electrode terminal 667 having the structure shown in FIGS. 4A and 4B, the wiring 710a and the wiring 710b are formed using the same conductive paste. The polymer film 665 can be firmly fixed.

  Further, the sensor 668 may include four electrode terminals 666a, an electrode terminal 666b, an electrode terminal 667a, and an electrode terminal 667b, as shown in FIGS. 5C and 5D. The electrode terminals 666a, 666b, 667a, and 667b are electrically connected to the concentration measuring unit 670 (see FIG. 1) through the wiring 710a, the wiring 710c, the wiring 710b, and the wiring 710d, respectively. For example, the concentration measurement unit 670 can be used to measure a current between the electrode terminal 666a and the electrode terminal 667a, and can be used to measure a voltage between the electrode terminal 666b and the electrode terminal 667b.

  Returning to FIG. 1, the alcohol concentration of the fuel gas 124 b in the fuel electrode tank 662 measured by the concentration measuring unit 670 is transmitted to the control unit 672. The control unit 672 determines whether or not the alcohol concentration measured by the concentration measuring unit 670 is within an appropriate range so that the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662 is within the appropriate range. The fuel supply processing unit 674 is controlled. The fuel supply processing unit 674 controls the supply amount of the fuel gas 124 b supplied from the fuel storage unit 676 to the fuel electrode tank 662 based on the control of the control unit 672.

  Further, the control unit 672 causes the warning presenting unit 680 to generate a warning if the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662 does not fall within an appropriate range even after the process of controlling the fuel supply processing unit 674 is repeated. .

  The fuel cell system 660 may further include a recovery processing unit 675. The recovery processing unit 675 performs processing for recovering and concentrating the gas that has not been consumed by the electrode reaction out of the fuel gas 124 b supplied to the fuel electrode tank 662 and returning it to the fuel storage unit 676 as the organic liquid fuel 124 a. The recovery processing unit 675 can obtain an aqueous alcohol solution by, for example, liquefying water and alcohol and removing other components through a gas-liquid separation membrane. In this way, the fuel gas 124b that has not been consumed by the electrode reaction can be reused.

  FIG. 6 is a diagram showing a configuration in which the fuel storage unit 676, the fuel supply processing unit 674, the fuel electrode tank 662, and the fuel cell main body 100 are integrally formed. Here, the fuel supply processing unit 674 includes a gasification processing unit 335 that gasifies the organic liquid fuel 124a to generate the fuel gas 124b, and an inverter 461.

  The fuel cell main body 100 is accommodated in the housing 338. A fuel storage portion 676 is provided below the housing 338 to store the organic liquid fuel 124a. A gasification processing unit 335 is provided below the organic liquid fuel 124 a in the fuel storage unit 676. The fuel storage portion 676 and the fuel electrode tank 662 are connected via a through-hole 341 provided in a part of the housing 338. Further, a gas permeable membrane 336 that permeates and discharges carbon dioxide generated by the electrode reaction is provided above the fuel electrode tank 662.

  The gasification processing unit 335 can be an atomization unit that emits high-frequency vibration such as ultrasonic vibration. The vibration generated by the atomization unit is conducted to the organic liquid fuel 124 a in the fuel storage unit 676. Due to this vibration, the organic liquid fuel 124a is atomized to generate a mist-like fuel gas 124b. The fuel gas 124 b enters the fuel electrode tank 662 through the through hole 341. Examples of the atomizing unit include ultrasonic vibration type atomizing units such as USH-400 manufactured by Akizuki Denshi Co., Ltd. and C-HM-2412 manufactured by Tech Jam Co., Ltd. Such an atomization unit can atomize the organic liquid fuel with good responsiveness. Further, an ultrasonic vibration type atomizing unit including a piezoelectric vibrator, such as an atomizing disk manufactured by FDK Corporation, may be used. Since such an atomization unit has low power consumption, the accumulation of carbon dioxide bubbles can be prevented and the stable power generation state can be maintained without increasing the load.

  Although not shown here, the control unit 672 controls the supply amount of the fuel gas 124 b from the fuel storage unit 676 to the fuel electrode tank 662 by changing the frequency or voltage in the inverter 461. As the inverter 461, for example, an EXCF series manufactured by Matsushita Electronic Components Co., Ltd. can be used. The control unit 672 changes the frequency or voltage of the inverter 461 according to the alcohol concentration of the fuel gas 124 b in the fuel electrode tank 662 measured by the concentration measuring unit 670. Thereby, the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662 can be maintained within an appropriate range.

  In addition, when the gasification processing unit 335 is an atomization unit, the atomization unit may be disposed at any location as long as vibration is transmitted to the organic liquid fuel 124a in the fuel storage unit 676. it can. As shown in FIG. 6, the atomization unit may be disposed on the bottom surface of the fuel storage portion 676 or on the side surface.

  In addition, the fuel storage unit 676 and the gasification processing unit 335 can be separated from each other by configuring such that vibration is transmitted to the organic liquid fuel 124a in the fuel storage unit 676 via cloth or paper. . When one end of a cloth or paper is immersed in the fuel storage unit 676 and the other end is brought into contact with the gasification processing unit 335, vibration from the gasification processing unit 335 can be conducted to the organic liquid fuel 124a in the fuel storage unit 676. The fuel gas 124b can be generated.

  The gasification processing unit 335 can include heating means such as a heater, and the organic liquid fuel 124a can be heated to vaporize the organic liquid fuel 124a to generate the fuel gas 124b as a vapor. . Further, the gasification processing unit 335 may include a bubbling means. In this case, the organic liquid fuel 124a is vaporized by bubbling the organic liquid fuel 124a using a carrier gas such as nitrogen, so that the organic liquid fuel 124a is obtained. Can be generated. In addition, the organic liquid fuel 124 a can be atomized by providing a nozzle in the fuel storage unit 676 and pressurizing the fuel storage unit 676.

  The gas permeable membrane 336 can be made of a material that selectively transmits carbon dioxide and does not transmit the fuel gas 124b. Any gas permeable membrane 336 may be used as long as it selectively transmits carbon dioxide. For example, a porous membrane having pores of about 0.05 μm to 4 μm can be used. . Such a configuration is taught in Japanese Patent Application Laid-Open No. 2001-102070.

  In addition, as another example of the gas permeable membrane 336, a gas-liquid separation filter including a porous base material and the non-porous membrane formed by coating the surface of the porous base material with a carbon dioxide selective permeable material. Can be used. Since the non-porous membrane is desired to allow carbon dioxide to pass through efficiently, it is preferable to reduce the thickness to some extent. For example, the average thickness is preferably 5 μm or less, more preferably 1 μm or less. In the case of such a thin film, it is difficult to produce by molding like a porous PTFE filter. Therefore, in the above configuration, a non-porous film formed by coating the surface of the porous substrate with a carbon dioxide permselective material is used. According to this configuration, the porous base material can function as a gas-liquid separator, and carbon dioxide can be selectively permeated through the non-porous membrane out of the gas permeated therethrough. Here, the non-porous film can be configured to contain, for example, a fluororesin.

  As described above, by using a material that selectively permeates carbon dioxide and does not permeate the fuel gas 124b as the gas permeable membrane 336, the carbon dioxide generated by the electrode reaction can be discharged from the fuel electrode tank 662 to the outside. it can. On the other hand, since the fuel gas 124b does not pass through the gas permeable membrane 336, it is possible to prevent the unreacted fuel gas 124b from being discharged to the outside. The surplus fuel gas 124b becomes droplets on the wall surface of the fuel electrode tank 662 and the like, but when the droplet grows to a certain size or more, it drops along the wall surface, is collected in the fuel storage unit 676, and is re-applied. Used.

  In the oxidant electrode 108, the oxidant 126 is introduced from an intake port 339 provided in the housing 338, and is discharged from an exhaust port 340 provided in the housing 338.

  FIG. 7 is a diagram showing another example of the fuel supply processing unit 674 shown in FIG. Here, the fuel cell system 660 may be configured to include two fuel storage units and two gasification processing units.

  In the fuel cell of FIG. 7, the first gasification processing unit 335a and the second gasification processing unit 335b are disposed in the first fuel storage unit 676a and the second fuel storage unit 676b, respectively. The first gasification processing unit 335a and the second gasification processing unit 335b transmit vibrations to the first fuel storage unit 676a and the second fuel storage unit 676b, respectively, and thereby gas the first component 481 and the second component 483, respectively. Turn into. The gasified component is introduced into the fuel electrode tank 662. The first gasification processing unit 335a and the second gasification processing unit 335b are connected to the first inverter 461a and the second inverter 461b, respectively, and the respective gasification amounts are controlled by the control unit 672.

  For example, the first component 481 and the second component 483 can be water and a highly concentrated aqueous methanol solution, respectively. In this case, the control by the control unit 672 is performed as follows. Based on the output from the concentration measurement unit 670, the control unit 672 determines whether or not the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662 is within an appropriate range. When the alcohol concentration of the fuel gas 124b is lower than the appropriate range, the gasification amount of the second component 483 from the second fuel storage portion 676b is increased. On the other hand, when the alcohol concentration of the fuel gas 124b is higher than the appropriate range, the gasification amount of the first component 481 from the first fuel storage portion 676a is increased.

  Here, since only carbon dioxide does not move to the oxidant electrode 108, it is necessary to discharge it from the fuel electrode tank 662. As described above, in the conventional direct methanol fuel cell, bubbles of carbon dioxide may remain in the fuel electrode, thereby inhibiting the progress of the reaction of the reaction formula (1). On the other hand, in the fuel cell system 660 of the present embodiment in which the organic liquid fuel 124a is gasified and supplied, there is no liquid in the fuel electrode tank 662 to generate bubbles, so that carbon dioxide bubbles are formed. Hateful. As a result, carbon dioxide does not stay on the surface of the fuel electrode 102. As shown in FIG. 6, if the gas permeable membrane 336 is provided in the fuel electrode tank 662, the carbon dioxide can be efficiently discharged to the outside. Thereby, reaction of the said Reaction formula (1) advances stably, and the stable output is obtained.

  The fuel supply processing unit 674 can be configured to include three or more fuel storage units and gasification processing units.

FIG. 8 is a diagram showing the configuration of the concentration measuring unit 670 in detail.
The concentration measuring unit 670 is based on a resistance measuring unit (R / O) 682 that measures a resistance value between the first electrode terminal 666 and the second electrode terminal 667 and a resistance value measured by the resistance measuring unit 682. A concentration calculation unit (S / O) 684 that calculates the alcohol concentration in the fuel electrode tank 662, and a reference showing the relationship between the resistance value between the first electrode terminal 666 and the second electrode terminal 667 and the methanol concentration A reference data storage unit 685 for storing data. As the resistance measuring unit 682, for example, an AC impedance meter having a bridge can be used. The resistance value between the first electrode terminal 666 and the second electrode terminal 667 can be measured using an alternating current with a low amplitude of 20 mV or less. The concentration calculation unit 684 refers to the reference data storage unit 685 and calculates the methanol concentration from the resistance value measured by the concentration calculation unit 684 based on the reference data.

  In addition, as shown in FIG. 9, the fuel cell system 660 may further include a pH sensor 686 and a temperature sensor 688. As shown in the above formula (1), carbon dioxide is generated at the fuel electrode 102. Therefore, the pH in the fuel electrode tank 662 may change depending on the concentration of carbon dioxide contained in the fuel electrode tank 662. Since the proton conductivity of the polymer membrane 665 may depend on temperature and pH, the concentration measuring unit 670 measures the methanol concentration in the fuel gas 124b in consideration of the temperature and pH in the fuel electrode tank 662. Is preferred. The pH sensor 686 and the temperature sensor 688 measure the pH and temperature in the anode tank 662, respectively. The reference data storage unit 685 (FIG. 8) can store the relationship between the resistance value between the first electrode terminal 666 and the second electrode terminal 667 and the methanol concentration for each temperature and each pH. Further, the reference data storage unit 685 can store a correction formula for the relationship between the resistance value between the first electrode terminal 666 and the second electrode terminal 667 and the methanol concentration for each temperature and each pH. In this way, the concentration measuring unit 670 can measure the methanol concentration of the fuel gas 124b in consideration of the temperature and pH in the fuel electrode tank 662, and can accurately measure the methanol concentration.

  As the temperature sensor 688, a thermocouple, a metal resistance temperature detector, a thermistor, an IC temperature sensor, a magnetic temperature sensor, a thermopile, a pyroelectric temperature sensor, or the like can be used. As the pH sensor 686, a commercially available pH meter can be used. When a pH meter having a temperature measurement function is used, the pH sensor 686 and the temperature sensor 688 can be formed integrally.

  FIG. 10 shows a diagram in which the temperature sensor 688 (or the pH sensor 686) and the sensor 668 are integrally formed. As shown in FIG. 10 (a), the sensor 668 may have a configuration in which a temperature sensor 688 (or pH sensor 686) is attached to the surface of the polymer film 665, or as shown in FIG. 10 (b). The temperature sensor 688 may be embedded in the polymer film 665. Further, as shown in FIG. 10C, the sensor 668 may be configured such that a film-like temperature sensor 688 (or pH sensor 686) is attached to the polymer film 665.

  Furthermore, as shown in FIG. 11, by using a combination of a plurality of sensors 668a, 668b, and 668c each including three or more types of polymer membranes having different proton conductivity depending on temperature and pH, alcohol in the anode tank 662 is used. Concentration, temperature, and pH can also be measured. Examples of combinations of such polymer membranes include (1) sulfonic acid group-containing polyperfluorocarbons such as Nafion, (2) sulfonic acid group-containing polyether ketones such as polyetheretherketone (PEEK), and (3) sulfone. An acid group polystyrene copolymer can be used. In this case, the concentration measurement unit 670 can include a plurality of resistance measurement units 682a, 682b, and 682c that measure the resistance values of the sensors 668a, 668b, and 668c, respectively. The concentration calculation unit 684 can detect the alcohol concentration of the fuel gas 124b based on the resistance values measured by the plurality of resistance measurement units 682a, 682b, and 682c in consideration of temperature and pH.

  Furthermore, for example, as shown in FIG. 9, the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662 can be obtained by using a temperature sensor 688 and using a combination of two or more polymer membranes having different proton conductivity depending on pH. And pH can also be measured.

  Further, as shown in FIG. 12, the sensor 668 may be provided on the wall portion of the fuel electrode tank 662. Further, as shown in FIG. 13, the sensor 668 may have a configuration in which a part of the solid polymer electrolyte membrane 114 of the fuel cell main body 100 is used as the polymer membrane 665 shown in FIG. 1.

  FIG. 14 is a view showing a modification of the sensor 668 having the configuration shown in FIGS. 12 and 13. FIG. 14A shows a modification of the sensor 668 shown in FIG. In the sensor 668, the first electrode terminal 666 and the second electrode terminal 667 may be provided outside the anode tank 662 so as not to directly contact the fuel gas 124 b in the anode tank 662. it can. If the polymer film 665 is in contact with the fuel gas 124 b in the fuel electrode tank 662, the first electrode terminal 666 and the second electrode terminal 667 are not provided in the fuel electrode tank 662. The resistance value between the electrode terminal 666 and the second electrode terminal 667 can be detected. With such a configuration, the first electrode terminal 666 and the second electrode terminal 667 are not always in contact with the fuel gas 124b, and therefore the first electrode terminal 666 and the second electrode terminal 667 are corroded by the fuel gas 124b. Can be prevented. Thereby, the 1st electrode terminal 666 and the 2nd electrode terminal 667 can be kept stable.

  FIG. 14B shows a modification of the sensor 668 shown in FIG. Here, in the sensor 668, the first electrode terminal 666 and the second electrode terminal 667 are not in direct contact with the fuel gas 124b in the fuel electrode tank 662, and the oxidant electrode 108 side of the solid polymer electrolyte membrane 114. It can be set as the structure provided in. Thereby, the 1st electrode terminal 666 and the 2nd electrode terminal 667 can be kept stable.

  In the above example, the fuel gas 124b is supplied directly from the fuel supply processing unit 674 to the fuel electrode tank 662. However, the fuel gas 124b is supplied to the fuel electrode tank 662 via the buffer tank 664. It can also be set as a form. FIG. 15 is a schematic diagram showing a mode in which the fuel gas 124 b is supplied to the fuel electrode tank 662 via the buffer tank 664. In this case, although not shown, the buffer tank 664 and the fuel electrode tank 662 can be configured such that the fuel gas 124b can be circulated through the piezoelectric pump. Here, in FIG. 15, the sensor 668 is provided in the buffer tank 664, but the sensor 668 may be provided in the fuel electrode tank 662. Further, the sensor 668 may be provided in a pipe connecting the containers.

  Next, the configuration of the fuel cell main body 100 shown in FIG. 1 will be described with reference to FIG. The fuel cell main body 100 has one or a plurality of single cell structures 101. FIG. 16 is a cross-sectional view schematically showing the single cell structure 101. Each single cell structure 101 includes a fuel electrode 102, an oxidant electrode 108 and a solid polymer electrolyte membrane 114. In the fuel cell main body 100, the fuel gas 124 b is supplied to the fuel electrode 102 of the single cell structure 101 through the fuel electrode side separator 120. Further, the oxidant 126 is supplied to the oxidant electrode 108 of each single cell structure 101 via the oxidant electrode side separator 122.

  The solid polymer electrolyte membrane 114 has a role of separating the fuel electrode 102 and the oxidant electrode 108 and moving hydrogen ions between them. For this reason, it is preferable that the solid polymer electrolyte membrane 114 is a membrane with high hydrogen ion conductivity. Further, it is preferably chemically stable and has high mechanical strength.

  The fuel electrode 102 and the oxidant electrode 108 respectively form a fuel electrode side catalyst layer 106 and an oxidant electrode side catalyst layer 112 containing carbon particles carrying a catalyst and solid electrolyte fine particles on the substrate 104 and the substrate 110, respectively. Can be configured. Examples of the catalyst include platinum and an alloy of platinum and ruthenium. The catalyst for the fuel electrode 102 and the oxidant electrode 108 may be the same or different. When the fuel cell system 660 has the configuration shown in FIG. 13, a region in the solid polymer electrolyte membrane 114 where the fuel electrode side catalyst layer 106 and the oxidant electrode side catalyst layer 112 are not provided is referred to as a polymer membrane 665. Use.

  By stacking the single cell structures 101 configured as described above, a fuel cell main body 100 including a fuel cell stack in which a plurality of single cell structures 101 are connected in series can be obtained.

  According to the fuel cell system 660 in the present embodiment, the alcohol concentration of the fuel gas 124b is measured with a simple configuration in which the first electrode terminal 666 and the second electrode terminal 667 are simply attached to the polymer film 665. Can do.

(Second embodiment)
FIG. 17 is a diagram showing an example of the configuration of the fuel cell system according to the second embodiment of the present invention. In the present embodiment, a cartridge 678 is attached to the fuel cell system 660.

  The cartridge 678 is configured to include a buffer tank 664 and a fuel storage portion 676. On the main body side 679 of the fuel cell system 660, a fuel cell main body 100, a fuel electrode tank 662, a fuel supply processing unit 674, a concentration measuring unit 670, and a control unit 672 are provided. The same components as those described in the first embodiment with reference to FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  Here, the fuel supply processing unit 674 is configured to gasify the organic liquid fuel 124a included in the fuel storage unit 676 of the cartridge 678 and supply the fuel gas 124b to the buffer tank 664 when the cartridge 678 is attached. The In the cartridge 678, the buffer tank 664 includes a sensor 668. On the main body side 679, the concentration measurement unit 670 has terminals (not shown) that are electrically connected to the first electrode terminal 666 and the second electrode terminal 667 of the sensor 668 when the cartridge 678 is attached. Provided. The fuel electrode tank 662 is configured such that the fuel gas 124 b can be introduced from the buffer tank 664.

  FIG. 18 is a schematic diagram showing a buffer tank 664 in the cartridge 678 and a fuel electrode tank 662 on the main body side 679. The fuel electrode tank 662 is provided with a fuel supply port 643, and the buffer tank 664 has a fitting portion 647 that fits with the fuel supply port 643 of the fuel electrode tank 662. On the side wall of the cartridge body 645, an electrode terminal 666a and an electrode terminal 667a that are electrically connected to the first electrode terminal 666 and the second electrode terminal 667 of the sensor 668, respectively, are provided. Here, the fuel cell main body 100 further includes an insulating sheet 130, a fuel electrode side current collector 132, and an oxidant electrode side current collector 134 in addition to the configuration shown in FIG. 17.

  Further, as shown in FIG. 19, the sensor 668 may be provided in the fuel electrode tank 662 on the main body side 679. Furthermore, as shown in FIG. 20, the fuel cell system 660 may be configured such that the cartridge 678 including only the fuel storage portion 676 can be removed. Although not shown, the cartridge 678 may include a valve. In addition, the sensor 668 can be provided on the wall portion of the cartridge 678. In this case, the sensor 668 exposed outside the cartridge 678 can be covered with a seal or the like, and the seal can be removed before being attached to the main body side 679. Thereby, it is possible to prevent liquid fuel from leaking from the cartridge 678 before the cartridge 678 is attached to the main body side 679.

  According to the fuel cell system 660 in the present embodiment, it is possible to detect the alcohol concentration of the fuel gas 124b when a cartridge containing the organic liquid fuel 124a is attached.

(Example 1)
An ultrasonic vibration type atomization unit was used as the gasification processing unit 335. As the polymer film 665, a Nafion N112 film (manufactured by DuPont, thickness of about 50 μm, width of about 5 mm, length of about 60 mm) is used, and Pt terminals (width of about 6 mm square) are formed on the surfaces of both ends of the polymer film 665 in the length direction. ) To which a sensor 668 was attached was prepared. The methanol-concentration was changed in the container to introduce a water-methanol mixed gas, and the resistance value between the electrodes was measured using an alternating current with a low amplitude of 10 mV or less using an alternating current impedance meter equipped with a bridge.

  FIG. 21 is a diagram showing the relationship between the amount of methanol permeated through the fuel electrode tank 662 and the resistance value. Here, the humidity of the water-methanol mixed gas was 100%. As shown in FIG. 21, the methanol permeation amount and the resistance value were in a substantially linear relationship. Thus, by utilizing the change in proton conductivity of the polymer membrane 665, the alcohol concentration could be detected with high accuracy.

(Example 2)
First, a fuel cell main body 100 similar to that shown in FIG. 16 was produced. As a catalyst contained in the fuel electrode side catalyst layer 106 and the oxidant electrode side catalyst layer 112, platinum (Pt) -ruthenium (Ru) alloy having a particle diameter of 3 to 5 nm is applied to carbon fine particles (Denka Black; manufactured by Denki Kagaku). Catalyst-supported carbon fine particles supported by 50% by weight were used. The alloy composition was 50 at% Ru, and the weight ratio of the alloy to the carbon fine powder was 1: 1. 18 g of 5 wt% Nafion solution manufactured by Aldrich Chemical Co. was added to 1 g of the catalyst-supporting carbon fine particles, and the mixture was stirred with an ultrasonic mixer at 50 ° C. for 3 hours to obtain a catalyst paste. 2 mg / cm ^{2 of} this paste was applied by screen printing on carbon paper (Toray: TGP-H-120) treated with water-repellent treatment with polytetrafluoroethylene and dried at 120 ° C. The agent electrode 108 was obtained. Next, the fuel electrode 102 and the oxidant electrode 108 obtained above were thermocompression bonded at 120 ° C. to a single solid polymer electrolyte membrane 114 (Nafion (registered trademark) manufactured by DuPont, film thickness 150 μm). A battery body 100 was produced.

  The fuel cell main body 100 thus manufactured was fixed in a stainless steel case, and the output was measured by changing the methanol concentration of the fuel gas. The supply of the oxidant to the oxidant electrode 108 was natural air intake. The results are shown in Table 1.

(Comparative example)
A fuel cell main body 100 was produced in the same manner as in Example 2. The fuel cell main body 100 was fixed in a stainless steel casing, and the output was measured by changing the methanol concentration of the organic liquid fuel. The results are shown in Table 2.

  As shown in Table 2, when an organic liquid fuel is used as the fuel to be supplied to the fuel electrode 102, when the methanol concentration is high (15% by volume), a crossover occurs and the output is greatly reduced. On the other hand, when fuel gas was used as the fuel, even if the methanol concentration was high (15% by volume), no reduction in output was observed. However, it has been found that even when fuel gas is used, the output decreases when the methanol concentration is further increased (20% by volume). Thus, even when fuel gas was used, it was shown that there was an appropriate alcohol concentration range in order to obtain high output.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. is there.

  In the above embodiment, the embodiment has been described in which the alcohol concentration of the fuel gas 124b is measured using the sensor 668 including a material whose proton conductivity changes according to the alcohol concentration of the fuel gas 124b. It is also possible to measure the alcohol concentration of the fuel gas 124b using a sensor including a material whose dimensions change according to the alcohol concentration of the fuel gas 124b.

  FIG. 22 is a diagram showing a sensor 698 that includes a material whose dimensions change depending on the alcohol concentration in the fuel gas 124b. The sensor 698 may include a polymer film 694 and a strain gauge 695 disposed on the polymer film 694, and the surface of the strain gauge 695 may be covered with a waterproof film 712. An electrical signal from the strain gauge 695 can be extracted from the wiring 713a and the wiring 713b.

  The strain gauge 695 is attached to the surface of the polymer film 694 or embedded therein. The strain gauge 695 can also be configured integrally with the polymer film 694. The strain gauge 695 may have any configuration. For example, a Wheatstone bridge circuit may be configured by four strain gauges, and the first terminal 696 and the second terminal may be configured by using a resistance change of the strain gauge due to strain as an electrical signal. 697 can be taken out. The concentration measuring unit 670 measures the alcohol concentration of the fuel gas 124b in the fuel electrode tank 662 based on the resistance value between the first terminal 696 and the second terminal 697.

  The polymer membrane 694 can be made of any material as long as the material changes in size according to the alcohol concentration of the fuel gas 124b. For example, the polymer membrane 694 is made of the same material as the solid polymer electrolyte membrane 114. can do.

  In addition, as shown in FIG. 23, the sensor 698 can have a structure in which a first terminal 696 and a second terminal 697 are provided on a quartz 722 attached to the surface of the polymer film 694. In this case, the concentration measuring unit 670 changes the transmission frequency from the first terminal 696 of the sensor 698, transmits a microwave or the like, receives the reflected wave from the second terminal 697, and increases the frequency according to the resonance frequency characteristic. A change in the size of the molecular film 694 can be detected.

FIG. 24 is a diagram illustrating another example of a sensor including a material whose dimensions change according to the alcohol concentration in the fuel gas 124b.
The sensor 704 is a capacitor including a first electrode 701 and a second electrode 702. 24A is a side view of the polymer film 700 and the first electrode 701 and the second electrode 702 that sandwich the polymer film 700, and FIG. 24B shows the sensor 704 as the first electrode. It is the top view seen from the 701 side. The first electrode 701 and the second electrode 702 are electrically connected to the concentration measurement unit 670 via a wiring 714a and a wiring 714b, respectively.

  In the sensor 704, the first electrode 701 and the second electrode 702 sandwich the polymer film 700. In this case, the polymer film 700 is made of an insulating material. The polymer film 700 can be made of any material as long as it is insulative and its dimensions change according to the alcohol concentration of the fuel gas 124b. Examples of the polymer film 700 include aromatic polyether, polyphenylene sulfide, polyimide, polyphosphazene, trifluorostyrene copolymer (BAM3G, manufactured by Ballard), and the like. In addition, the polymer membrane having a sulfonic acid group used as the solid polymer electrolyte membrane 114 of the fuel cell main body 100 as described above is irradiated with an electron beam, UV, X-rays, or immersed in a salt to obtain an insulating property. It is also possible to use what has been done.

It is a figure which shows an example of a structure of the fuel cell system in embodiment of this invention. It is a figure which shows a sensor in detail. It is a figure which shows the other example of a sensor. It is a figure which shows the other example of a sensor. It is a figure which shows the other example of a sensor. It is a figure which shows an example of a structure of a fuel supply process part. It is a figure which shows the other example of a structure of a fuel supply process part. It is a figure which shows the structure of the density | concentration measurement part shown in FIG. 1 in detail. It is a figure which shows the structure of the fuel cell system which further contains a pH sensor and a temperature sensor. It is a figure which shows the other example of a sensor. It is a figure which shows the density | concentration measurement part of the structure which combined the 3 or more types of polymer film from which the change of the electrical resistance with respect to temperature and pH differs. It is a figure which shows the other example of a structure of a fuel cell system. It is a figure which shows the other example of a structure of a fuel cell system. It is a figure which shows the modification of a sensor. It is a figure which shows the other example of a structure of a fuel cell system. It is sectional drawing which showed typically the single cell structure of the fuel cell main body. It is a figure which shows an example of a structure of the fuel cell system in embodiment of this invention. It is a schematic diagram which shows the buffer tank in the cartridge shown in FIG. 17, and the fuel electrode tank in a main body side. It is a figure which shows the other example of a structure of a fuel cell system. It is a figure which shows the other example of a structure of a fuel cell system. It is a figure which shows the relationship between the methanol permeation amount of a fuel electrode tank, and resistance value. It is a figure which shows the other example of a structure of a sensor. It is a figure which shows the other example of a structure of a sensor. It is a figure which shows the other example of a structure of a sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Fuel cell main body 101 Single cell structure 102 Fuel electrode 104 Base 106 Fuel electrode side catalyst layer 108 Oxidant electrode 110 Base body 112 Oxidant electrode side catalyst layer 114 Solid polymer electrolyte membrane 120 Fuel electrode side separator 122 Oxidant electrode side separator 124a Organic liquid fuel 124b Fuel gas 126 Oxidant 130 Insulating sheet 132 Fuel electrode side current collector 134 Oxidant electrode side current collector 335 Gasification processing unit 336 Gas permeable membrane 338 Housing 339 Inlet port 340 Exhaust port 341 Through port 461 Inverter 481 First fuel component 483 Second fuel component 643 Fuel supply port 645 Cartridge body 647 Fitting portion 660 Fuel cell system 662 Fuel electrode tank 664 Buffer tank 665 Polymer film 666 First electrode terminal 666a Electrode terminal 667 Second electrode Terminal 667a Electrode terminal 668 668a, 668b, 668c Sensor 670 Concentration measurement unit 672 Control unit 674 Fuel supply processing unit 675 Recovery processing unit 676 Fuel storage unit 676a First fuel storage unit 676b Second fuel storage unit 678 Cartridge 679 Main body side 680 Warning presentation unit 682 Resistance measurement unit 682a, 682b, 682c Resistance measurement unit 684 Concentration calculation unit 685 Reference data storage unit 686 pH sensor 688 Temperature sensor 694 Polymer film 695 Strain gauge 696 First terminal 697 Second terminal 698 Sensor 700 Polymer film 701 First electrode 702 Second electrode 704 Sensor 710a, 710b, 710c, 710d Wiring 711 Conductive paste 712 Waterproof film 713a, 713b Wiring 714a, 714b Wiring

Claims (21)

A fuel cell system using alcohol gas as fuel,
A fuel cell main body including a solid polymer electrolyte membrane, and a fuel electrode and an oxidizer electrode disposed on the solid polymer electrolyte membrane;
A container containing the alcohol gas;
A concentration detector for detecting the alcohol concentration of the alcohol gas in the container;
A fuel cell system comprising: The fuel cell system according to claim 1, wherein
The concentration detector has proton conductivity, includes a polymer membrane provided in the container, and determines the alcohol concentration of the alcohol gas in the container based on a change in proton conductivity of the polymer membrane. A fuel cell system for detecting. The fuel cell system according to claim 2, wherein
The concentration detection unit includes a pair of electrode terminals disposed on the polymer film, a resistance measurement unit that measures a resistance value between the electrode terminals, and the alcohol gas based on the resistance value measured by the resistance measurement unit. And a concentration calculation unit for calculating the alcohol concentration of the fuel cell system. The fuel cell system according to claim 3, wherein
In the concentration detection unit, the electrode terminal is provided outside the container. The fuel cell system according to claim 3 or 4,
The fuel cell system, wherein the concentration detector has a hydrophobic film covering the electrode terminal. The fuel cell system according to any one of claims 2 to 5,
The solid polymer electrolyte membrane is provided in the container;
A fuel cell system, wherein a part of the solid polymer electrolyte membrane is used as the polymer membrane. The fuel cell system according to any one of claims 2 to 6,
Including a plurality of polymer membranes having different proton conductivities with respect to temperature or pH;
The concentration detector detects the alcohol concentration of the alcohol gas in consideration of the temperature or pH of the alcohol gas in the container based on a change in proton conductivity of each of the plurality of polymer membranes. A fuel cell system. The fuel cell system according to any one of claims 2 to 7,
The fuel cell system, wherein the polymer membrane includes a protonic acid group. The fuel cell system according to any one of claims 2 to 8,
The fuel cell system, wherein the polymer membrane is crosslinked. The fuel cell system according to any one of claims 1 to 9,
A fuel cell system, further comprising gasification means for gasifying a liquid fuel containing alcohol, wherein the gasified alcohol gas is supplied to the container. The fuel cell system according to claim 10, wherein
The fuel cell system further comprising a control unit that controls driving of the gasification means in accordance with the alcohol concentration detected by the concentration detection unit. The fuel cell system according to claim 10 or 11,
The cartridge further includes a cartridge configured to be removable from the fuel cell main body and containing the liquid fuel,
The fuel cell system characterized in that the gasification means gasifies the liquid fuel contained in the cartridge. The fuel cell system according to claim 10 or 11,
It further includes a plurality of liquid fuel storage portions that respectively store liquid fuels having different alcohol concentrations,
The fuel gas system, wherein the gasification means gasifies the liquid fuel for each liquid fuel. The fuel cell system according to claim 13, wherein
The fuel cell system according to claim 1, wherein the liquid fuel container is a cartridge configured to be detachable from the fuel cell main body. The fuel cell system according to any one of claims 1 to 14,
Further comprising a temperature sensor for measuring the temperature in the container;
The fuel cell system, wherein the concentration detector corrects an alcohol concentration of the alcohol gas in the container according to a temperature measured by the temperature sensor. The fuel cell system according to any one of claims 1 to 15,
A pH measurement unit for measuring pH in the container;
The concentration detection unit corrects the alcohol concentration of the alcohol gas in the container according to the pH measured by the pH measurement unit. The fuel cell system according to any one of claims 1 to 16,
A warning presenting section for presenting warnings;
A control unit that instructs the warning presenting unit to present a warning when the alcohol concentration of the alcohol gas in the container detected by the concentration detecting unit is outside a predetermined range;
The fuel cell system further comprising: A device for measuring alcohol concentration,
A polymer membrane having proton conductivity and having proton conductivity changed according to the alcohol concentration in the gas containing alcohol;
Based on a change in proton conductivity of the polymer membrane, a concentration detector that detects an alcohol concentration in the gas;
An alcohol concentration measuring device comprising: The alcohol concentration measuring apparatus according to claim 18,
The concentration detection unit includes a pair of electrode terminals disposed on the polymer film, a resistance measurement unit that measures a resistance value between the electrode terminals, and a resistance value measured by the conductivity measurement unit in the gas. And an alcohol concentration measuring device for converting the alcohol concentration into an alcohol concentration measuring device. A method for measuring alcohol concentration,
Introducing a polymer film having proton conductivity into a container containing alcohol gas to be measured;
Detecting a change in proton conductivity of the polymer membrane;
Detecting the alcohol concentration of the alcohol gas based on the change in proton conductivity;
A method for measuring an alcohol concentration, comprising: In the alcohol concentration measuring method according to claim 20,
The step of detecting the change in proton conductivity includes a step of measuring a resistance value between a pair of electrode terminals disposed in the polymer membrane,
The step of detecting the alcohol concentration includes a step of calculating an alcohol concentration of the alcohol gas based on the resistance value.

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