WO2021075381A1 - Fuel cell system - Google Patents

Fuel cell system Download PDF

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Publication number
WO2021075381A1
WO2021075381A1 PCT/JP2020/038335 JP2020038335W WO2021075381A1 WO 2021075381 A1 WO2021075381 A1 WO 2021075381A1 JP 2020038335 W JP2020038335 W JP 2020038335W WO 2021075381 A1 WO2021075381 A1 WO 2021075381A1
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Prior art keywords
fuel
electrode
cleaning
supply
fuel cell
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PCT/JP2020/038335
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French (fr)
Japanese (ja)
Inventor
拓也 辻口
明洋 高里
齊藤　利幸
中井　基生
厚 久保
裕介 上田
Original Assignee
株式会社ジェイテクト
国立大学法人金沢大学
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Application filed by 株式会社ジェイテクト, 国立大学法人金沢大学 filed Critical 株式会社ジェイテクト
Publication of WO2021075381A1 publication Critical patent/WO2021075381A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/008—Disposal or recycling of fuel cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/043—Processes for controlling fuel cells or fuel cell systems applied during specific periods
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
    • H01M8/04537—Electric variables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
    • H01M8/04746—Pressure; Flow
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
    • H01M8/04858—Electric variables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1009—Fuel cells with solid electrolytes with one of the reactants being liquid, solid or liquid-charged
    • H01M8/1011—Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/84—Recycling of batteries or fuel cells

Definitions

  • This disclosure relates to a fuel cell system.
  • the direct liquid fuel cell includes a fuel electrode that oxidizes fuel, an air electrode that reduces an oxidant gas such as air, and an electrolyte membrane that conducts ion conduction between the air electrode and the fuel electrode.
  • the fuel electrode is the anode and the air electrode is the cathode.
  • Both the fuel electrode and the air electrode are provided with a catalyst layer containing an electrode catalyst that accelerates the rate of redox reaction of the electrodes.
  • Japanese Patent Application Laid-Open No. 2009-217975 discloses a direct methanol fuel cell using methanol as a fuel and a direct formic acid fuel cell using formic acid as a fuel.
  • the present disclosure provides a fuel cell system having a direct liquid fuel cell that cleans the fuel electrode, removes generated by-products, and suppresses a decrease in the output voltage (cell voltage) of the fuel cell.
  • the fuel cell in a fuel cell system having a direct liquid fuel cell configured to use a liquid containing formic acid or alcohol as fuel, the fuel cell comprises a fuel electrode and air. It has a pole and an electrolyte membrane, and the fuel pole has a fuel inlet to which the fuel is supplied and a fuel outlet to which the fuel is discharged.
  • the fuel cell system includes a fuel supply cleaning device configured to supply the fuel toward the fuel inlet or supply a cleaning fluid toward the fuel inlet to clean the fuel electrode.
  • a control device that switches between the supply of the fuel by the fuel supply cleaning device and the cleaning of the fuel electrode.
  • the cleaning fluid contains the fuel
  • the control device generates power from the fuel supply cleaning device at the time of power generation.
  • the fuel is supplied to the fuel electrode at a flow rate and the elapsed time during power generation exceeds a predetermined elapsed time, or when the power generation voltage of the fuel cell during power generation is smaller than the predetermined voltage, the power generation is performed.
  • the fuel is supplied to the fuel electrode at a cleaning flow rate that is larger than the flow rate to clean the fuel electrode, and after the cleaning is completed, the flow rate of the fuel supplied to the fuel electrode is calculated from the cleaning flow rate. It is configured to change to the power generation flow rate.
  • the fuel cell in a fuel cell system having a direct liquid fuel cell configured to use a liquid containing formic acid or alcohol as fuel, the fuel cell comprises a fuel electrode and air. It has a pole and an electrolyte membrane, and the fuel pole has a fuel inlet to which the fuel is supplied and a fuel outlet to which the fuel is discharged.
  • the fuel cell system is configured to supply the fuel to the fuel inlet and to supply the cleaning fluid to the fuel inlet to clean the fuel electrode.
  • a cleaning device and a control device for switching between supply of the fuel by the fuel supply device and cleaning of the fuel electrode by the cleaning device are included.
  • the cleaning fluid contains pure water
  • the control device receives the fuel from the fuel supply device at the time of power generation. Is supplied to the fuel electrode, and when the elapsed time during power generation exceeds a predetermined elapsed time, or when the power generation voltage of the fuel cell during power generation is smaller than the predetermined voltage, the cleaning device is switched to. The cleaning fluid is supplied to the fuel electrode to clean the fuel electrode, and after the cleaning is completed, the fuel supply device is switched to supply the fuel to the fuel electrode.
  • the fuel outlet is arranged on the upper side of the fuel electrode, and the fuel inlet is the fuel electrode of the fuel electrode. It is arranged on the lower side, and a fluid supply pipe is arranged below the fuel inlet so that the fluid supply pipe guides one of the fuel and the cleaning fluid to the fuel inlet.
  • the fluid supply pipe is connected to the fuel inlet, and has a supply on-off valve capable of switching the fluid supply pipe between an open state and a closed state.
  • the control device controls the supply on-off valve to an open state at the time of the power generation or the cleaning, and when instructed to stop the power generation, switches to the cleaning device to use the cleaning fluid. After supplying to the fuel electrode and filling the fuel electrode with the cleaning fluid, the supply on-off valve is controlled to be closed to stop the power generation.
  • the fuel electrode of the fuel cell can be cleaned.
  • by-products generated at the fuel electrode can be removed, and a decrease in the generated voltage of the fuel cell can be suppressed. Therefore, it is possible to maintain the power generation efficiency of the fuel cell and improve the fuel efficiency.
  • the fuel supply device also serves as the cleaning device, cleaning is performed only by the fuel supply device without providing the cleaning device, so that the configuration of the fuel cell system can be simplified. Moreover, since the fuel electrode is cleaned with fuel, it is possible to generate electricity even during the cleaning process.
  • the fuel electrode of the fuel cell is cleaned with pure water, the fuel electrode can be cleaned without generating by-products. As a result, the cleaning can be performed more cleanly and the cleaning time can be shortened.
  • the fuel electrode by filling the fuel electrode with pure water instead of fuel in the power generation stopped state, deterioration due to drying of the electrolyte membrane and corrosion of the fuel electrode can be prevented, and the life of the fuel cell can be extended. ..
  • FIG. 1 is a diagram illustrating an overall configuration of a fuel cell system according to the first embodiment.
  • FIG. 2 is an exploded perspective view illustrating the structure of the fuel cell of the first embodiment.
  • FIG. 3 is a flowchart illustrating a cleaning process of the fuel cell of the first embodiment.
  • FIG. 4 is a flowchart illustrating a first fuel supply process, which is a fuel supply process according to the first embodiment.
  • FIG. 5 is a flowchart illustrating a first cleaning process, which is a cleaning process according to the first embodiment.
  • FIG. 6 is a flowchart illustrating the fuel supply stop processing in the first embodiment.
  • FIG. 7 is a diagram illustrating the overall configuration of the fuel cell system according to the second embodiment.
  • FIG. 1 is a diagram illustrating an overall configuration of a fuel cell system according to the first embodiment.
  • FIG. 2 is an exploded perspective view illustrating the structure of the fuel cell of the first embodiment.
  • FIG. 3 is a flowchart illustrating a cleaning process of
  • FIG. 8 is a cross-sectional view illustrating a fluid detecting means provided on a fuel electrode (fuel electrode current collector).
  • FIG. 9 is a diagram illustrating a cleaning process of the fuel cell of the second embodiment.
  • FIG. 10 is a flowchart illustrating a second fuel supply process, which is a fuel supply process according to the second embodiment.
  • FIG. 11 is a flowchart illustrating a second cleaning process, which is a cleaning process according to the second embodiment.
  • FIG. 12 is a diagram when the corrosion drying suppression treatment is applied to the second embodiment.
  • FIG. 13 is a flowchart illustrating a corrosion drying suppression process, which is a fuel supply stop process in the second embodiment.
  • the fuel cell 7 of the fuel cell system 1 described in the present embodiment is a direct liquid fuel cell that uses an aqueous solution of alcohol such as formic acid or methanol as a fuel, and below, a direct formic acid type that uses formic acid as a fuel.
  • a fuel cell will be described as an example.
  • the direct liquid fuel cell means a fuel cell in which liquid fuel is directly injected into the fuel electrode without reforming.
  • the direct formic acid type fuel cell is a fuel cell fuel that uses formic acid as a fuel and directly feeds the formic acid into the fuel electrode 10 (see FIG. 2) without reforming the formic acid.
  • the axes are orthogonal to each other, the Z-axis direction indicates a direction vertically upward, and the X-axis direction and the Y-axis direction are horizontal. It shows the direction.
  • FIG. 1 is a diagram showing an overall configuration of a fuel cell system 1X (1) including the fuel cell 7X (7) of the first embodiment
  • FIG. 2 is an exploded perspective view illustrating the configuration of the fuel cell 7X. ..
  • the fuel cell system 1X includes a control device 40, a fuel supply device 500 (fuel tank 50, fuel supply pipe 51, fuel pump 52), a fuel cell 7X (7), and a drainage tank 60. Etc.
  • the control device 40 (including, for example, a CPU, a storage device, etc.) includes a measuring means (for example, a voltmeter) that internally measures the generated voltage of the fuel cell 7X (7), and an elapsed time during power generation, although not shown. It is equipped with a timer to measure. Further, the control device 40 is connected to the fuel pump 52 constituting the fuel supply device 500 and controls the fuel pump 52.
  • a measuring means for example, a voltmeter
  • the fuel tank 50 stores a liquid (formic acid aqueous solution) containing a predetermined concentration of formic acid as a fuel.
  • concentration of formic acid as a fuel is, for example, about 10 to 40 [%].
  • one end of the fuel supply pipe 51 is connected to the fuel tank 50, and the other end of the fuel supply pipe 51 is connected to the fuel inlet 7A of the fuel cell 7X (7).
  • the fuel pump 52 is an electric pump, which is provided in the fuel supply pipe 51, and pumps (supplies) the fuel in the fuel tank 50 toward the fuel inlet 7A of the fuel cell 7X (7). Further, the fuel pump 52 is controlled by the control device 40 in terms of the amount of pumping (supply amount) and the start / stop of pumping.
  • the drainage tank 60 stores the fuel after being used in the fuel cell 7X (7) and the water generated and recovered in the air electrode 20.
  • the other end of the fuel discharge pipe 61 is connected to the drainage tank 60, and one end of the fuel discharge pipe 61 is connected to the fuel outlet 7B of the fuel cell 7X (7).
  • the drainage tank 60 is connected to the other end of the recovery pipe 62, and the one end side of the recovery pipe 62 is connected to the recovery hole 23B provided below the air electrode 20.
  • an exhaust port (not shown) that communicates the inside and the outside is provided in the upper part of the drainage tank 60, and when the pressure inside the drainage tank 60 increases, the gas in the drainage tank 60 is exhausted. It flows out of the drainage tank 60 from the mouth (not shown).
  • the fuel supply device 500 includes a fuel tank 50, a fuel supply pipe 51, and a fuel pump 52. At the time of power generation, the fuel supply device 500 drives the fuel pump 52 to supply (pump) the fuel (geic acid aqueous solution) of the power generation flow rate to the fuel electrode 10 toward the fuel inlet 7A. Further, the fuel supply device 500 is also used as a cleaning device, and supplies fuel having a cleaning flow rate, which is a flow rate larger than the generated flow rate, to the fuel electrode 10 to clean the fuel electrode 10.
  • the control device 40 controls the fuel supply device 500 and switches between the operation as the fuel supply device and the operation as the cleaning device.
  • the fuel supply device 500 according to the first embodiment may be referred to as a fuel supply cleaning device.
  • the fuel cell 7X (7) has a fuel inlet 7A into which fuel from the fuel tank 50 flows in and a fuel outlet 7B in which the used fuel is discharged, and generates electricity using the inflowing fuel.
  • the details of the structure of the fuel cell 7X (7) will be described below.
  • the fuel cell 7X (7) has a configuration in which the electrolyte membrane 30 is sandwiched between the air electrode 20 and the fuel electrode 10.
  • the air electrode 20 is configured by laminating an air electrode catalyst layer 21, an air electrode diffusion layer 22, and an air electrode current collector 23.
  • the fuel electrode 10 is configured by laminating a fuel electrode catalyst layer 11, a fuel electrode diffusion layer 12, and a fuel electrode current collector 13X (13).
  • the air electrode current collector 23 is a plate-shaped metal or the like having a thickness of about 1 to 10 [mm] and having conductivity.
  • the air electrode current collector 23 has a supply port 23A that supplies pumped air from the outside in order to allow ambient air (oxygen) to flow into the air electrode diffusion layer 22 (expose the air electrode diffusion layer 22 to the outside air). It is provided above, and a recovery hole 23B is provided below to recover the used air and the generated water.
  • an electric load for example, an electric motor
  • An air flow groove 23C is formed as a narrow flow path on the surface of the air electrode current collector 23 on the side in contact with the air electrode diffusion layer 22.
  • the air flow groove 23C may be formed in the same shape as the fuel flow groove 13B.
  • the air electrode diffusion layer 22 is formed in a layered shape having a thickness of about 0.05 to 0.5 [mm].
  • the air electrode diffusion layer 22 is a porous material that can permeate water and air and has electron conductivity, and for example, carbon paper or carbon cloth can be used.
  • the air electrode diffusion layer 22 guides the air (oxygen) that has flowed in from the supply port 23A of the air electrode current collector 23 to the air electrode catalyst layer 21 while diffusing it. Oxygen contained in the outside air permeates the air electrode diffusion layer 22 and reaches the electrode catalyst particles of the air electrode catalyst layer 21.
  • the air electrode catalyst layer 21 is formed in a layered shape having a thickness of about 0.05 to 0.5 [mm].
  • the air electrode catalyst layer 21 includes electrode catalyst particles of air electrodes (not shown) and an electrode catalyst carrier (not shown) that supports the electrode catalyst particles.
  • the electrode catalyst particles of the air electrode 20 are catalyst particles that accelerate the reaction rate of the reaction of reducing oxygen in the air, and for example, platinum (Pt) particles can be used.
  • the electrode catalyst carrier may be any as long as it can support the electrode catalyst particles and has conductivity, for example, carbon powder can be used.
  • the redox reaction represented by (Equation 1) proceeds by the electrode catalyst particles of the air electrode catalyst layer 21.
  • the generated water (H 2 O) is collected through the recovery hole 23B and guided to the drainage tank 60 via the recovery pipe 62. 2H + +1/2 O 2 + 2e - ⁇ H 2 O ( Equation 1)
  • the fuel electrode current collector 13X (13) is a plate-shaped metal or the like having a thickness of about 1 to 10 [mm] and having conductivity.
  • the fuel electrode current collector 13X (13) has a fuel distribution surface 13A in contact with the fuel electrode diffusion layer 12, and a fuel distribution groove 13B having an opening on the side of the fuel electrode diffusion layer 12 on the fuel distribution surface 13A. Is formed.
  • the fuel flow groove 13B is a narrow flow path so that fuel can flow without stagnation.
  • the electronic e - to recover, on the periphery of the fuel flow channel 13B, the land portion 13E in contact with the fuel electrode diffusing layer 12 is formed.
  • an electric load for example, an electric motor
  • the fuel flow groove 13B is a plurality of flow groove portions extending in a substantially horizontal direction from one edge portion (or the other edge portion) of the fuel electrode current collector 13X (13) to the opposite edge portion (or one edge portion). It has 13C. Further, each of the plurality of flow groove portions 13C is connected by a folded groove portion 13D formed in the vicinity of one edge portion or the other edge portion of the fuel electrode current collector 13X (13) and extending in a substantially vertical direction. Further, the fuel flow groove 13B has a fuel inlet 7A formed below the fuel electrode current collector 13X (13) and a fuel outlet 7B formed above the fuel electrode current collector 13X (13). It is connected.
  • the fuel flowing into the fuel inflow port 7A is guided from the side of one edge portion to the side of the other edge portion by the flow groove portion 13C, is changed in direction by the folded groove portion 13D, and is transferred to the next flow groove portion 13C. It is guided from the other edge side to the one edge side, and while repeating the direction change at the next folded groove portion 13D, it flows through the fuel flow groove 13B which is a serpentine type flow path, and the fuel electrode. It is diffused into the diffusion layer 12.
  • the fuel electrode diffusion layer 12 is formed in a layered shape having a thickness of about 0.05 to 0.5 [mm].
  • the fuel electrode diffusion layer 12 is a porous material that allows an aqueous solution of formic acid to permeate inside and has electron conductivity. For example, carbon paper or carbon cloth can be used.
  • the fuel electrode diffusion layer 12 guides the fuel flowing through the fuel flow groove 13B formed on the fuel flow surface 13A of the fuel electrode current collector 13X (13) to the fuel electrode catalyst layer 11 while diffusing the fuel.
  • the fuel electrode catalyst layer 11 is formed in a layered shape having a thickness of about 0.05 to 0.5 [mm].
  • the fuel electrode catalyst layer 11 includes electrode catalyst particles (not shown) and an electrode catalyst carrier (not shown) that supports the electrode catalyst particles.
  • the electrode catalyst particles of the fuel electrode 10 are catalyst particles that accelerate the rate of oxidation reaction of formic acid, which is a fuel, and for example, palladium (Pd) particles can be used.
  • the electrode catalyst carrier may be any as long as it can support the electrode catalyst particles and has conductivity, for example, carbon powder can be used.
  • the oxidation reaction shown in (Equation 2) proceeds by the electrode catalyst particles of the fuel electrode catalyst layer 11. HCOOH ⁇ CO 2 + 2H + + 2e - ( Equation 2)
  • the electrolyte membrane 30 is formed in the form of a thin film having a thickness of about 0.01 to 0.3 [mm].
  • the electrolyte membrane 30 is sandwiched between the fuel electrode catalyst layer 11 of the fuel electrode 10 and the air electrode catalyst layer 21 of the air electrode 20, has no electron conductivity, and is a proton exchange membrane capable of transmitting water and H +. Is.
  • a perfluoroethylene sulfonic acid-based membrane such as Nafion (registered trademark) manufactured by DuPont can be used.
  • the present specification describes the fuel electrode catalyst layer 11, the fuel electrode diffusion layer 12, the electrolyte membrane 30, the air electrode catalyst layer 21, and the air electrode diffusion layer 22 described above, which are joined and integrated. In the document, it may be referred to as a membrane / electrode assembly (MEA; Membrane Electrolyte Assembly).
  • the formic acid aqueous solution is sent from the fuel tank 50 to the fuel supply pipe 51, and flows into the fuel flow groove 13B from the fuel inlet 7A of the fuel electrode current collector 13X (13). As the formic acid aqueous solution flows through the fuel flow groove 13B, it permeates into the fuel electrode diffusion layer 12 and reaches the surface of the electrode catalyst particles of the fuel electrode catalyst layer 11. Then, the oxidation reaction of formic acid represented by the above (formula 2) proceeds on the surface of the electrode catalyst particles of the fuel electrode catalyst layer 11.
  • Carbon dioxide CO 2 produced by the oxidation reaction of formic acid shown in (Equation 2) gathers to form bubbles and is discharged from the fuel electrode 10, and proton H + passes through the electrolyte membrane 30 and permeates the electrode of the air electrode catalyst layer 21. Reach the catalyst particles.
  • the fuel cell 7X (7) generates electricity. Then, in the fuel electrode catalyst layer 11, the carbon dioxide CO 2 produced by the oxidation reaction of formic acid of (Equation 2) gathers to form bubbles, flows through the fuel electrode diffusion layer 12 and the fuel flow groove 13B, and flows through the fuel electrode diffusion layer 12 and the fuel flow groove 13B to the fuel outlet. It is discharged from 7B and stored in the drainage tank 60 via the fuel discharge pipe 61.
  • carbon dioxide CO 2 is generated on the surface of the electrode catalyst particles of the fuel electrode catalyst layer 11, but when carbon dioxide CO 2 stays on the surface of the electrode catalyst particles of the fuel electrode catalyst layer 11, formic acid becomes the electrode catalyst. Since it is difficult to be adsorbed on the surface, it inhibits the progress of the oxidation reaction of formic acid shown in (Equation 2). Further, the formic acid shown in (Formula 2) is also caused by poisoning the electrode catalyst particles of the fuel electrode catalyst layer 11 by carbon monoxide CO or the like generated by the side reaction of the oxidation reaction of formic acid shown in (Formula 2). The progress of the oxidation reaction is inhibited.
  • FIG. 3 is a flowchart illustrating the entire process of the fuel cell cleaning process.
  • FIG. 4 is a flowchart illustrating a first fuel supply process, which is a fuel supply process according to the first embodiment.
  • FIG. 5 is a flowchart illustrating a first cleaning process, which is a cleaning process according to the first embodiment.
  • FIG. 6 is a flowchart illustrating the fuel supply stop processing in the first embodiment.
  • the fuel cell system 1X activates the control device 40 (see FIG. 1) upon receiving an instruction to start power generation, and operates at predetermined intervals (for example, a number).
  • the fuel cell cleaning process is executed in 100 msec).
  • the operation mode is the operation mode of the fuel cell system 1X (1), and is a power generation mode in which fuel is supplied and the fuel cell 7X (7) (see FIG. 1) generates power, and a power generation mode in which power generation is stopped and the fuel electrode 10 is stopped. It consists of a cleaning mode for cleaning (see FIG. 1) and a stop mode for stopping all operations.
  • step S010A the control device 40 determines whether or not the operation mode is the power generation mode, and if it is determined that the operation mode is the power generation mode (Yes), the process proceeds to step S020A, and if not (No). ) Proceeds to step S010B.
  • step S020A the control device 40 determines whether or not the elapsed time during power generation exceeds the predetermined elapsed time, and if it is determined that the elapsed time exceeds the predetermined elapsed time (Yes), the process proceeds to step S050A. If not, the process proceeds to step S030A.
  • the control device 40 starts an internal timer with an instruction to start power generation, starts counting, and stops counting with an instruction to stop power generation.
  • the control device 40 integrates the counted count values and obtains the elapsed time based on the integrated count values.
  • the predetermined elapsed time is stored in advance in the control device 40 and is a value determined by an experiment or the like.
  • the predetermined elapsed time is, for example, several minutes to several tens of minutes.
  • step S030A the control device 40 measures the generated voltage of the fuel cell 7X and determines whether or not it is smaller than the predetermined voltage. If it is determined that the generated voltage is smaller than the predetermined voltage (Yes), the process proceeds to step S050A. If not (No), the process proceeds to step S040A.
  • the predetermined voltage is stored in advance in the control device 40, and is a value determined based on the power generation voltage required for cleaning. For example, when the required power generation voltage is 0.8V to 1.0V, the predetermined voltage is 0.6V to 0.7V.
  • step S040A the control device 40 performs a fuel supply process (first fuel supply process, see FIG. 4), and proceeds to step S010C.
  • step S050A the control device 40 sets the operation mode to the cleaning mode, and proceeds to step S060A.
  • step S060A the control device 40 initializes the elapsed time (initializes the integrated count value, refer to step S020A), and proceeds to step S010C.
  • step S010B the control device 40 determines whether or not the operation mode is the cleaning mode, and if the operation mode is determined to be the cleaning mode (Yes), the process proceeds to step S020B, and if not (No). ) Proceeds to step S040C.
  • step S020B the control device 40 determines whether or not the cleaning is completed, and if it is determined that the cleaning is completed (Yes), the process proceeds to step S050B, and if not (No), the process proceeds to step S040B. To proceed.
  • the control device 40 drives, for example, an internal timer at the same time as the start of cleaning to start counting, and when the predetermined count value (count value corresponding to the predetermined elapsed time) stored in advance is exceeded, the cleaning is completed. It is determined that the cleaning has been completed (determined after the cleaning is completed).
  • step S040B the control device 40 performs a cleaning process (first cleaning process, see FIG. 5), and proceeds to step S010C.
  • step S050B the control device 40 sets the operation mode to the power generation mode (returns to the time of power generation), and proceeds to the process in step S010C.
  • step S040C the control device 40 performs the fuel supply stop processing (see FIG. 6), and proceeds to the processing in step S010C.
  • step S010C the control device 40 determines whether or not there is a power generation stop instruction, and if it is determined that there is a power generation stop instruction (Yes), the process proceeds to step S050C, and if not (No), the process is performed. finish.
  • the control device 40 receives a stop signal from the outside (for example, a power generation stop switch) or an output signal from another device in the system as a power generation stop instruction. be able to.
  • step S050C the control device 40 sets the operation mode to the stop mode and ends the process.
  • FIG. 4 shows the details of step S040A (fuel supply processing) of FIG.
  • the control device 40 performs the first fuel supply process in step S040A of the fuel cell cleaning process (see FIG. 3). Specifically, in step SA110, the control device 40 drives the fuel pump 52 of the fuel supply device 500 to supply the fuel of the preset power generation flow rate required for power generation to the fuel electrode 10 and process it. (See Fig. 1).
  • the power generation flow rate is, for example, 3 ml / min.
  • FIG. 5 shows the details of step S040B (cleaning process) of FIG.
  • the control device 40 performs the first cleaning process in step S040B of the fuel cell cleaning process (see FIG. 3). Specifically, in step SA210, the control device 40 drives the fuel pump 52 of the fuel supply device 500 to supply fuel having a cleaning flow rate, which is a flow rate larger than the generated flow rate, to the fuel electrode 10. 10 is washed and the process is completed. To do.
  • the cleaning flow rate is larger than the power generation flow rate, and is, for example, 10 ml / min.
  • FIG. 6 shows the details of step S040C (fuel supply stop processing) of FIG.
  • the control device 40 performs the fuel supply stop processing in step S040C of the fuel supply stop processing (see FIG. 3). Specifically, in step SA310, the control device 40 stops the fuel pump 52 of the fuel supply device 500 to stop the fuel supply.
  • FIG. 7 is a diagram showing the overall configuration of the fuel cell system 1Y (1) of the second embodiment.
  • FIG. 8 is a cross-sectional view illustrating the fluid detecting means 7C provided in the fuel electrode current collector 13Y (13).
  • the fuel cell system 1Y includes a fuel cell 7Y, a fluid detection means 7C, a fuel on-off valve 53, and a fuel on-off valve 53 instead of the fuel cell 7X of the fuel cell system 1X of the first embodiment of FIG. It differs from the cleaning device 700 in that it has a supply on-off valve 82.
  • the fuel outlet 7B is arranged on the upper side of the fuel electrode 10, and the fuel inlet 7A is arranged on the lower side of the fuel electrode.
  • a fluid supply pipe 81 that guides fuel or cleaning fluid (pure water) to the fuel inlet 7A is connected. Further, the other end of the fluid supply pipe 81 is connected to the fuel supply pipe 51 and the cleaning fluid pipe 71, which will be described later, respectively.
  • the fluid supply pipe 81 is provided with a supply on-off valve 82 capable of switching the fluid supply pipe 81 between an open state and a closed state.
  • the fuel supply pipe 51 is provided with a fuel on-off valve 53 capable of switching the fuel supply pipe 51 between an open state and a closed state.
  • the cleaning fluid pipe 71 is provided with a cleaning on-off valve 73 capable of switching the cleaning fluid pipe 71 between an open state and a closed state.
  • a fluid detecting means 7C is provided in the flow groove portion 13C near the fuel outlet 7B of the fuel electrode current collector 13Y (13) with the fuel outlet 7B interposed therebetween.
  • the fluid detecting means 7C is supplied with the cleaning fluid CF (pure water) from the fuel inflow port 7A (see FIG. 7), and is filled with the cleaning fluid CF (pure water) from the lower side to the upper side.
  • a signal corresponding to the cleaning fluid CF (pure water) is transmitted to the control device 40.
  • the fluid detecting means 7C may be any as long as it can acquire the level (water level in the case of pure water) of the cleaning fluid CF.
  • various detection means can be selected as the fluid detection means 7C by utilizing the difference in physical and chemical properties between pure water and formic acid.
  • the fluid detecting means 7C can use a pH meter.
  • the fluid detecting means 7C can use an ohmmeter.
  • the cleaning device 700 includes a pure water tank 70 (cleaning fluid tank), a cleaning fluid pipe 71, a cleaning fluid pump 72, and a cleaning on-off valve 73.
  • the pure water tank 70 (cleaning fluid tank) stores pure water as a cleaning fluid. Further, one end of the cleaning fluid pipe 71 is connected to the pure water tank 70, and the other end of the cleaning fluid pipe 71 is connected to the fluid supply pipe 81.
  • the cleaning fluid pump 72 is an electric pump, which is provided in the cleaning fluid pipe 71, and pumps pure water (cleaning fluid) in the pure water tank 70 toward the fuel inlet 7A of the fuel cell 7Y (7). Supply). Further, the cleaning fluid pump 72 is controlled by the control device 40 in terms of the amount of pumping (supply amount) and the start / stop of pumping.
  • FIG. 7 shows a state in which the fuel cell 7Y is in a power generation state and the fuel supply device 500 is operating.
  • FIG. 9 shows a state in which the fuel cell 7Y is in the power generation stopped state (the fuel supply device 500 is stopped) and the cleaning device 700 is operating.
  • each on-off valve when each of the quadrants facing each other along the flow path direction is black, it indicates a closed state, and when it is not black, it indicates an open state.
  • the cleaning process of the fuel cell 7Y of the second embodiment will be described with reference to FIGS. 10 and 11.
  • the flowchart of the entire process of the second embodiment is the same as that of FIG. 3, the details of the process of step 040A of FIG. 3 are the flowchart of FIG. 10, and the details of the process of step 040B of FIG. 3 are shown in FIG.
  • the details of the process of step 040C of FIG. 3 are the flowchart of FIG.
  • step S040A (see FIG. 3) of the fuel cell cleaning process, the control device 40 executes the fuel supply process (second fuel supply process) and proceeds to step SB110.
  • step SB110 the control device 40 determines whether or not the fuel on-off valve 53 is in the closed state and the wash on-off valve 73 is in the open state, and the fuel on-off valve 53 is in the closed state and the wash on-off valve 73 is in the open state. If it is determined that the state is open (Yes), the process proceeds to step SB120, and if not (No), the process proceeds to step SB130.
  • step SB120 the control device 40 stops driving the cleaning fluid pump 72 of the cleaning device 700, stops the supply of pure water (cleaning fluid), and proceeds to step SB130.
  • step SB130 the control device 40 closes the fuel on-off valve 53 and the cleaning on-off valve 73, and proceeds to step SB140.
  • step SB140 the control device 40 drives the fuel pump 52 of the fuel supply device 500 to supply the fuel of the generated flow rate to the fuel electrode 10 and end the process (return to the time of power generation).
  • step S040B (see FIG. 3) of the fuel cell cleaning process, the control device 40 executes the cleaning process (second cleaning process) and proceeds to step SB210.
  • step SB210 the control device 40 determines whether or not the fuel on-off valve 53 is in the open state and the wash on-off valve 73 is in the closed state, and the fuel on-off valve 53 is in the open state and the wash on-off valve 73 is in the open state. If it is determined that the state is closed (Yes), the process proceeds to step SB220, and if not (No), the process proceeds to step SB230.
  • step SB 220 the control device 40 stops driving the cleaning fluid pump 72 of the cleaning device 700, stops the supply of pure water (cleaning fluid), and proceeds to step SB 230.
  • step SB230 the control device 40 sets the fuel on-off valve 53 in the closed state and the cleaning on-off valve 73 in the open state, and proceeds to the process in step SB240.
  • step SB240 the control device 40 drives the cleaning fluid pump 72 of the cleaning device 700 to supply pure water (cleaning fluid) to the fuel electrode 10 to clean the fuel electrode 10 and end the process.
  • the fuel cell system 1Y activates the control device 40 when receiving an instruction for corrosion drying suppression processing (for example, a start signal from a start switch or the like) to suppress corrosion drying. Execute the process.
  • an instruction for corrosion drying suppression processing for example, a start signal from a start switch or the like
  • step SC010 the control device 40 determines whether or not the supply on-off valve 82 is in the open state, and if it is determined that the supply on-off valve 82 is in the open state (Yes), the process proceeds to step SC020. If not (No), the process proceeds to step SC010A.
  • step SC010A the control device 40 sets the supply on-off valve 82 to the open state, and proceeds to the process in step SC020.
  • step SC020 the control device 40 sets the fuel on-off valve 53 in the closed state and the cleaning on-off valve 73 in the open state, and proceeds to the process in step SC030.
  • step SC030 the control device 40 drives the cleaning fluid pump 72 of the cleaning device 700 to supply pure water (cleaning fluid) to the fuel electrode 10 and proceed to step SC040.
  • step SC040 the control device 40 determines whether or not the fuel electrode 10 is filled with pure water (cleaning fluid), and the fuel electrode 10 is filled with pure water (cleaning fluid). If it is determined (Yes), the process proceeds to step SC050, and if not (No), the process ends. The control device 40 determines whether or not the state is filled with pure water (cleaning fluid) based on the signal from the fluid detecting means 7C.
  • step SC050 the control device 40 stops driving the cleaning fluid pump 72 of the cleaning device 700, stops the supply of pure water (cleaning fluid), and proceeds to step SC060.
  • step SC060 the control device 40 sets the supply on-off valve 82 to the closed state and ends the process (stops power generation).
  • the fuel electrode 10 of the fuel cell 7 can be cleaned. As a result, by-products generated at the fuel electrode 10 can be removed, and a decrease in the generated voltage of the fuel cell 7 can be suppressed. Therefore, the power generation efficiency of the fuel cell 7 can be maintained and the fuel efficiency can be improved.
  • the fuel supply device 500 since the fuel supply device 500 also serves as a cleaning device and cleaning is performed only by the fuel supply device 500 without providing the cleaning device, the configuration of the fuel cell system 1 (1X) should be simplified. Can be done. Further, since the fuel electrode 10 is cleaned with fuel, it is possible to generate electricity even during the cleaning process.
  • the fuel electrode 10 of the fuel cell 7 is cleaned with pure water (cleaning fluid), the fuel electrode 10 can be cleaned without generating by-products. As a result, the cleaning can be performed more cleanly and the cleaning time can be shortened.
  • the fuel cell system 1 of the present disclosure is not limited to the configuration, structure, shape, appearance, etc. described in the present embodiment, and various changes, additions, and deletions can be made without changing the gist of the present disclosure. ..
  • the fuel on-off valve 53 and the cleaning on-off valve 73 in the fuel cell system 1Y shown in FIG. 7 are not indispensable configurations, and the closed state and the opening state may be switched between the fuel pump 52 and the cleaning fluid pump 72, respectively.
  • the fuel on-off valve 53 and the cleaning on-off valve 73 may be synchronously switched between the closed state and the open state to close and open the fluid supply pipe 81.
  • a pH meter and an ohmmeter are exemplified as the fluid detecting means 7C, a capacitance meter that detects the difference in capacitance between the fuel (formic acid aqueous solution) and the cleaning fluid (pure water) may also be used.
  • the cleaning fluid is pure water or distilled water
  • the cleaning treatment may be performed using a fluid whose temperature is higher than room temperature by heating using waste heat or the like generated by the power generation of the fuel cell.
  • the control device 40 measures the generated voltage of the fuel cell 7 (see FIG. 1) after determining that the cleaning is completed in step S020B, and is higher than the predetermined voltage. If it is determined that the fuel cell 7 is small, it is determined that the fuel cell 7 cannot supply sufficient power and has reached the end of its life, and a signal for notifying an abnormality is output to a higher-level system (for example, an automobile) to which the fuel cell system 1 is applied. It may be something to do.

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Abstract

This fuel cell system has a direct-liquid-type fuel cell that uses a liquid including formic acid or an alcohol as fuel, wherein the fuel cell has a fuel electrode, an air electrode, and an electrolyte film, and the fuel electrode has a fuel inlet port through which fuel is supplied and a fuel outlet port through which fuel is discharged. The fuel cell system includes: a fuel-supply and cleaning device that supplies fuel toward the fuel inlet port or supplies a cleaning fluid toward the fuel inlet port to clean the fuel electrode; and a control device that performs switching between the cleaning of the fuel electrode and the fuel supply carried out by the fuel-supply and cleaning device.

Description

燃料電池システムFuel cell system
　本開示は、燃料電池システムに関する。 This disclosure relates to a fuel cell system.
　燃料電池には様々な種類があり、その中には、液体の燃料を改質せずに燃料極に直接投入する直接液体型燃料電池がある。直接液体型燃料電池は、燃料を酸化する燃料極と、空気などの酸化剤ガスを還元する空気極と、空気極と燃料極との間にイオン伝導を行う電解質膜とを備えている。ここで、燃料極はアノードで、空気極はカソードである。燃料極および空気極の両方の電極では、電極の酸化還元反応の速度を促進させる電極触媒を含む触媒層が設けられている。 There are various types of fuel cells, and among them, there is a direct liquid fuel cell that directly inputs the liquid fuel to the fuel electrode without reforming it. The direct liquid fuel cell includes a fuel electrode that oxidizes fuel, an air electrode that reduces an oxidant gas such as air, and an electrolyte membrane that conducts ion conduction between the air electrode and the fuel electrode. Here, the fuel electrode is the anode and the air electrode is the cathode. Both the fuel electrode and the air electrode are provided with a catalyst layer containing an electrode catalyst that accelerates the rate of redox reaction of the electrodes.
　直接液体型燃料電池に関する技術が各種提案されている。例えば、日本国特開２００９－２１７９７５号公報には、燃料にメタノールを用いる直接メタノール型燃料電池と、燃料にギ酸を用いる直接ギ酸型燃料電池とが開示されている。 Various technologies related to direct liquid fuel cells have been proposed. For example, Japanese Patent Application Laid-Open No. 2009-217975 discloses a direct methanol fuel cell using methanol as a fuel and a direct formic acid fuel cell using formic acid as a fuel.
　しかし、日本国特開２００９－２１７９７５号公報に記載の直接液体燃料電池は、燃料極に供給された燃料を電極触媒を用いて酸化させるが、一酸化炭素等の副生成物により、燃料極の電極触媒が被毒して燃料電池の出力電圧（セル電圧）が低下することが問題となっている。 However, the direct liquid fuel cell described in Japanese Patent Application Laid-Open No. 2009-217975 oxidizes the fuel supplied to the fuel electrode using an electrode catalyst, but the by-product such as carbon monoxide causes the fuel electrode to oxidize. The problem is that the electrode catalyst is poisoned and the output voltage (cell voltage) of the fuel cell drops.
　本開示は、燃料極を洗浄し発生した副生成物を除去し、燃料電池の出力電圧（セル電圧）の低下を抑制する直接液体型の燃料電池を有する燃料電池システムを提供する。 The present disclosure provides a fuel cell system having a direct liquid fuel cell that cleans the fuel electrode, removes generated by-products, and suppresses a decrease in the output voltage (cell voltage) of the fuel cell.
　本開示の第１の態様によれば、ギ酸またはアルコールを含む液体を燃料として使用するように構成された直接液体型の燃料電池を有する燃料電池システムにおいて、前記燃料電池は、燃料極と、空気極と、電解質膜とを有し、前記燃料極は、前記燃料が供給される燃料流入口と、前記燃料が排出される燃料流出口とを有している。燃料電池システムは、前記燃料流入口へ向けて前記燃料を供給する、又は、前記燃料流入口へ向けて洗浄用流体を供給し前記燃料極を洗浄する、ように構成された燃料供給洗浄装置と、前記燃料供給洗浄装置による前記燃料の供給と前記燃料極の洗浄とを切り替える制御装置と、を含む。 According to the first aspect of the present disclosure, in a fuel cell system having a direct liquid fuel cell configured to use a liquid containing formic acid or alcohol as fuel, the fuel cell comprises a fuel electrode and air. It has a pole and an electrolyte membrane, and the fuel pole has a fuel inlet to which the fuel is supplied and a fuel outlet to which the fuel is discharged. The fuel cell system includes a fuel supply cleaning device configured to supply the fuel toward the fuel inlet or supply a cleaning fluid toward the fuel inlet to clean the fuel electrode. , A control device that switches between the supply of the fuel by the fuel supply cleaning device and the cleaning of the fuel electrode.
　本開示の第２の態様によれば、上記第１の態様に係る燃料電池システムにおいて、前記洗浄用流体は、前記燃料を含み、前記制御装置は、発電時には、前記燃料供給洗浄装置から、発電流量で前記燃料を前記燃料極に供給し、前記発電時の経過時間が所定経過時間を超えた場合、または、前記発電時の前記燃料電池の発電電圧が所定電圧よりも小さい場合に、前記発電流量よりも多い流量である洗浄流量で前記燃料を前記燃料極に供給して前記燃料極を洗浄し、前記洗浄の終了後、前記燃料極に供給される前記燃料の流量を前記洗浄流量から前記発電流量に変更するように構成される。 According to the second aspect of the present disclosure, in the fuel cell system according to the first aspect, the cleaning fluid contains the fuel, and the control device generates power from the fuel supply cleaning device at the time of power generation. When the fuel is supplied to the fuel electrode at a flow rate and the elapsed time during power generation exceeds a predetermined elapsed time, or when the power generation voltage of the fuel cell during power generation is smaller than the predetermined voltage, the power generation is performed. The fuel is supplied to the fuel electrode at a cleaning flow rate that is larger than the flow rate to clean the fuel electrode, and after the cleaning is completed, the flow rate of the fuel supplied to the fuel electrode is calculated from the cleaning flow rate. It is configured to change to the power generation flow rate.
　本開示の第３の態様によれば、ギ酸またはアルコールを含む液体を燃料として使用するように構成された直接液体型の燃料電池を有する燃料電池システムにおいて、前記燃料電池は、燃料極と、空気極と、電解質膜とを有し、前記燃料極は、前記燃料が供給される燃料流入口と、前記燃料が排出される燃料流出口とを有している。燃料電池システムは、前記燃料流入口へ向けて前記燃料を供給するように構成された燃料供給装置と、前記燃料流入口へ向けて洗浄用流体を供給し前記燃料極を洗浄するように構成された洗浄装置と、前記燃料供給装置による前記燃料の供給と前記洗浄装置による前記燃料極の洗浄とを切り替える制御装置と、を含む。 According to a third aspect of the present disclosure, in a fuel cell system having a direct liquid fuel cell configured to use a liquid containing formic acid or alcohol as fuel, the fuel cell comprises a fuel electrode and air. It has a pole and an electrolyte membrane, and the fuel pole has a fuel inlet to which the fuel is supplied and a fuel outlet to which the fuel is discharged. The fuel cell system is configured to supply the fuel to the fuel inlet and to supply the cleaning fluid to the fuel inlet to clean the fuel electrode. A cleaning device and a control device for switching between supply of the fuel by the fuel supply device and cleaning of the fuel electrode by the cleaning device are included.
　本開示の第４の態様によれば、上記第３の態様に係る燃料電池システムにおいて、前記洗浄用流体は、純水を含み、前記制御装置は、発電時には、前記燃料供給装置から、前記燃料を前記燃料極に供給し、前記発電時の経過時間が所定経過時間を超えた場合、または、前記発電時の前記燃料電池の発電電圧が所定電圧よりも小さい場合に、前記洗浄装置に切り替え、前記洗浄用流体を前記燃料極に供給して前記燃料極を洗浄し、前記洗浄の終了後、前記燃料供給装置に切り替え、前記燃料を前記燃料極に供給する。 According to the fourth aspect of the present disclosure, in the fuel cell system according to the third aspect, the cleaning fluid contains pure water, and the control device receives the fuel from the fuel supply device at the time of power generation. Is supplied to the fuel electrode, and when the elapsed time during power generation exceeds a predetermined elapsed time, or when the power generation voltage of the fuel cell during power generation is smaller than the predetermined voltage, the cleaning device is switched to. The cleaning fluid is supplied to the fuel electrode to clean the fuel electrode, and after the cleaning is completed, the fuel supply device is switched to supply the fuel to the fuel electrode.
　本開示の第５の態様によれば、上記第４の態様に係る燃料電池システムにおいて、前記燃料流出口は、前記燃料極の上方の側に配置され、前記燃料流入口は、前記燃料極の下方の側に配置されており、前記燃料流入口から下方には流体供給配管が配置されており、該流体供給配管が前記燃料及び前記洗浄用流体のうち一方を前記燃料流入口へ導くように、該燃料流入口と接続されており、前記流体供給配管は、前記流体供給配管を開口状態と閉鎖状態に切り替え可能な供給開閉弁を有している。前記制御装置は、前記発電時または前記洗浄の際には、前記供給開閉弁を開口状態に制御し、前記発電を停止させる指示があった場合、前記洗浄装置に切り替えて、前記洗浄用流体を前記燃料極に供給し、前記燃料極を前記洗浄用流体で満たした後、前記供給開閉弁を閉鎖状態に制御して、前記発電を停止させるように構成される。 According to the fifth aspect of the present disclosure, in the fuel cell system according to the fourth aspect, the fuel outlet is arranged on the upper side of the fuel electrode, and the fuel inlet is the fuel electrode of the fuel electrode. It is arranged on the lower side, and a fluid supply pipe is arranged below the fuel inlet so that the fluid supply pipe guides one of the fuel and the cleaning fluid to the fuel inlet. The fluid supply pipe is connected to the fuel inlet, and has a supply on-off valve capable of switching the fluid supply pipe between an open state and a closed state. The control device controls the supply on-off valve to an open state at the time of the power generation or the cleaning, and when instructed to stop the power generation, switches to the cleaning device to use the cleaning fluid. After supplying to the fuel electrode and filling the fuel electrode with the cleaning fluid, the supply on-off valve is controlled to be closed to stop the power generation.
　第１の態様及び第３の態様によれば、燃料電池の燃料極を洗浄することができる。これにより、燃料極で発生した副生成物を除去し、燃料電池の発電電圧の低下を抑制することができる。従って、燃料電池の発電効率を維持し燃費を向上させることができる。 According to the first aspect and the third aspect, the fuel electrode of the fuel cell can be cleaned. As a result, by-products generated at the fuel electrode can be removed, and a decrease in the generated voltage of the fuel cell can be suppressed. Therefore, it is possible to maintain the power generation efficiency of the fuel cell and improve the fuel efficiency.
　第２の態様によれば、燃料供給装置が洗浄装置を兼ねることで洗浄装置を設けることなく燃料供給装置のみにより洗浄を行うため、燃料電池システムの構成をシンプルにすることができる。また燃料を用いて燃料極を洗浄するため、洗浄処理中であっても発電をすることが可能である。 According to the second aspect, since the fuel supply device also serves as the cleaning device, cleaning is performed only by the fuel supply device without providing the cleaning device, so that the configuration of the fuel cell system can be simplified. Moreover, since the fuel electrode is cleaned with fuel, it is possible to generate electricity even during the cleaning process.
　第４の態様によれば、燃料電池の燃料極を純水により洗浄するため、副生成物を発生させることなく燃料極を洗浄できる。これにより、より清浄に洗浄できるとともに、洗浄時間を短縮することができる。 According to the fourth aspect, since the fuel electrode of the fuel cell is cleaned with pure water, the fuel electrode can be cleaned without generating by-products. As a result, the cleaning can be performed more cleanly and the cleaning time can be shortened.
　第５の態様によれば、発電停止状態において、燃料極を燃料の代わりに純水で満たすことで電解質膜の乾燥による劣化と燃料極の腐食を防止し、燃料電池の寿命を延ばすことができる。 According to the fifth aspect, by filling the fuel electrode with pure water instead of fuel in the power generation stopped state, deterioration due to drying of the electrolyte membrane and corrosion of the fuel electrode can be prevented, and the life of the fuel cell can be extended. ..
図１は、第１の実施形態における燃料電池システムの全体構成を説明する図である。FIG. 1 is a diagram illustrating an overall configuration of a fuel cell system according to the first embodiment. 図２は、第１の実施形態の燃料電池の構造を説明する分解斜視図である。FIG. 2 is an exploded perspective view illustrating the structure of the fuel cell of the first embodiment. 図３は、第１の実施形態の燃料電池の洗浄処理を説明するフローチャートである。FIG. 3 is a flowchart illustrating a cleaning process of the fuel cell of the first embodiment. 図４は、第１の実施形態における燃料供給処理である第１燃料供給処理を説明するフローチャートである。FIG. 4 is a flowchart illustrating a first fuel supply process, which is a fuel supply process according to the first embodiment. 図５は、第１の実施形態における洗浄処理である第１洗浄処理を説明するフローチャートである。FIG. 5 is a flowchart illustrating a first cleaning process, which is a cleaning process according to the first embodiment. 図６は、第１の実施形態における燃料供給停止処理を説明するフローチャートである。FIG. 6 is a flowchart illustrating the fuel supply stop processing in the first embodiment. 図７は、第２の実施形態における燃料電池システムの全体構成を説明する図である。FIG. 7 is a diagram illustrating the overall configuration of the fuel cell system according to the second embodiment. 図８は、燃料極（燃料極集電体）に設けられた流体検知手段を説明する断面図である。FIG. 8 is a cross-sectional view illustrating a fluid detecting means provided on a fuel electrode (fuel electrode current collector). 図９は、第２の実施形態の燃料電池の洗浄処理を説明する図である。FIG. 9 is a diagram illustrating a cleaning process of the fuel cell of the second embodiment. 図１０は、第２の実施形態における燃料供給処理である第２燃料供給処理を説明するフローチャートである。FIG. 10 is a flowchart illustrating a second fuel supply process, which is a fuel supply process according to the second embodiment. 図１１は、第２の実施形態における洗浄処理である第２洗浄処理を説明するフローチャートである。FIG. 11 is a flowchart illustrating a second cleaning process, which is a cleaning process according to the second embodiment. 図１２は、第２の実施形態に腐食乾燥抑制処理を適用した場合の図である。FIG. 12 is a diagram when the corrosion drying suppression treatment is applied to the second embodiment. 図１３は、第２の実施形態における燃料供給停止処理である腐食乾燥抑制処理を説明するフローチャートである。FIG. 13 is a flowchart illustrating a corrosion drying suppression process, which is a fuel supply stop process in the second embodiment.
　以下に、本開示の実施の形態の燃料電池システム１について、図面を用いて説明する。なお、本実施の形態にて説明する燃料電池システム１の燃料電池７は、ギ酸またはメタノール等のアルコールの水溶液を燃料とする直接液体型燃料電池であり、以下ではギ酸を燃料とする直接ギ酸型燃料電池を例として説明する。ここで、直接液体型燃料電池とは、液体の燃料を、改質せずに燃料極に直接投入する燃料電池を意味する。そして、直接ギ酸型燃料電池は、燃料としてギ酸を用い、ギ酸を改質せずに燃料極１０（図２参照）に直接投入する燃料電池燃料である。なお、図中にＸ軸、Ｙ軸、Ｚ軸が記載されている場合、各軸は互いに直交しており、Ｚ軸方向は鉛直上方に向かう方向を示し、Ｘ軸方向とＹ軸方向は水平方向を示している。 Hereinafter, the fuel cell system 1 according to the embodiment of the present disclosure will be described with reference to the drawings. The fuel cell 7 of the fuel cell system 1 described in the present embodiment is a direct liquid fuel cell that uses an aqueous solution of alcohol such as formic acid or methanol as a fuel, and below, a direct formic acid type that uses formic acid as a fuel. A fuel cell will be described as an example. Here, the direct liquid fuel cell means a fuel cell in which liquid fuel is directly injected into the fuel electrode without reforming. The direct formic acid type fuel cell is a fuel cell fuel that uses formic acid as a fuel and directly feeds the formic acid into the fuel electrode 10 (see FIG. 2) without reforming the formic acid. When the X-axis, Y-axis, and Z-axis are described in the drawing, the axes are orthogonal to each other, the Z-axis direction indicates a direction vertically upward, and the X-axis direction and the Y-axis direction are horizontal. It shows the direction.
［第１の実施形態の燃料電池システム１Ｘ（１）の全体構成（図１）］
　図１は、第１の実施形態の燃料電池７Ｘ（７）を含む燃料電池システム１Ｘ（１）の全体構成を示す図であり、図２は燃料電池７Ｘの構成を説明する分解斜視図である。燃料電池システム１Ｘは、図１に示すように、制御装置４０と、燃料供給装置５００（燃料タンク５０、燃料供給配管５１、燃料ポンプ５２）と、燃料電池７Ｘ（７）と、排液タンク６０等を有している。 [Overall configuration of the fuel cell system 1X (1) of the first embodiment (FIG. 1)]
FIG. 1 is a diagram showing an overall configuration of a fuel cell system 1X (1) including the fuel cell 7X (7) of the first embodiment, and FIG. 2 is an exploded perspective view illustrating the configuration of the fuel cell 7X. .. As shown in FIG. 1, the fuel cell system 1X includes a control device 40, a fuel supply device 500 (fuel tank 50, fuel supply pipe 51, fuel pump 52), a fuel cell 7X (7), and a drainage tank 60. Etc.
　制御装置４０（例えば、ＣＰＵ、記憶装置等を含む）は、図示は省略するが内部に燃料電池７Ｘ（７）の発電電圧を計測する計測手段（例えば、電圧計）と、発電時の経過時間を計測するタイマーを備えている。また、制御装置４０は、燃料供給装置５００を構成する燃料ポンプ５２に接続され、燃料ポンプ５２を制御する。 The control device 40 (including, for example, a CPU, a storage device, etc.) includes a measuring means (for example, a voltmeter) that internally measures the generated voltage of the fuel cell 7X (7), and an elapsed time during power generation, although not shown. It is equipped with a timer to measure. Further, the control device 40 is connected to the fuel pump 52 constituting the fuel supply device 500 and controls the fuel pump 52.
　燃料タンク５０には、燃料となる所定濃度のギ酸を含む液体（ギ酸水溶液）が蓄えられている。燃料となるギ酸の濃度は、例えば１０～４０［％］程度である。また燃料タンク５０には燃料供給配管５１の一方端が接続され、燃料供給配管５１の他方端は燃料電池７Ｘ（７）の燃料流入口７Ａに接続されている。 The fuel tank 50 stores a liquid (formic acid aqueous solution) containing a predetermined concentration of formic acid as a fuel. The concentration of formic acid as a fuel is, for example, about 10 to 40 [%]. Further, one end of the fuel supply pipe 51 is connected to the fuel tank 50, and the other end of the fuel supply pipe 51 is connected to the fuel inlet 7A of the fuel cell 7X (7).
　燃料ポンプ５２は電動ポンプであり、燃料供給配管５１に設けられており、燃料タンク５０内の燃料を燃料電池７Ｘ（７）の燃料流入口７Ａに向けて圧送（供給）する。また、燃料ポンプ５２は、制御装置４０により、圧送する量（供給量）、圧送の開始・停止を制御される。 The fuel pump 52 is an electric pump, which is provided in the fuel supply pipe 51, and pumps (supplies) the fuel in the fuel tank 50 toward the fuel inlet 7A of the fuel cell 7X (7). Further, the fuel pump 52 is controlled by the control device 40 in terms of the amount of pumping (supply amount) and the start / stop of pumping.
　排液タンク６０には、燃料電池７Ｘ（７）内で使用された後の燃料と、空気極２０にて発生して回収された水が蓄えられている。排液タンク６０には燃料排出配管６１の他方端が接続され、燃料排出配管６１の一方端は燃料電池７Ｘ（７）の燃料流出口７Ｂに接続されている。また排液タンク６０には、回収配管６２の他方端が接続され、回収配管６２の一方端の側は、空気極２０の下方に設けられた回収孔２３Ｂに接続されている。さらに、排液タンク６０の上部には、内部と外部を連通する排気口（不図示）が設けられており、排液タンク６０の内部の圧力が高まると、排液タンク６０内の気体が排気口（不図示）から排液タンク６０外へ流出する。 The drainage tank 60 stores the fuel after being used in the fuel cell 7X (7) and the water generated and recovered in the air electrode 20. The other end of the fuel discharge pipe 61 is connected to the drainage tank 60, and one end of the fuel discharge pipe 61 is connected to the fuel outlet 7B of the fuel cell 7X (7). Further, the drainage tank 60 is connected to the other end of the recovery pipe 62, and the one end side of the recovery pipe 62 is connected to the recovery hole 23B provided below the air electrode 20. Further, an exhaust port (not shown) that communicates the inside and the outside is provided in the upper part of the drainage tank 60, and when the pressure inside the drainage tank 60 increases, the gas in the drainage tank 60 is exhausted. It flows out of the drainage tank 60 from the mouth (not shown).
　燃料供給装置５００は、燃料タンク５０と、燃料供給配管５１と、燃料ポンプ５２とを有する。燃料供給装置５００は、発電時には、燃料ポンプ５２を駆動し燃料流入口７Ａへ向けて発電流量の燃料（ギ酸水溶液）を燃料極１０に供給（圧送）する。また、燃料供給装置５００は、洗浄装置と兼用されており、発電流量よりも多い流量である洗浄流量の燃料を燃料極１０に供給して燃料極１０を洗浄する。制御装置４０は、燃料供給装置５００を制御し、燃料供給装置としての動作と洗浄装置としての動作を切り替える。なお、第１の実施形態に係る燃料供給装置５００は、燃料供給洗浄装置と呼称されてもよい。 The fuel supply device 500 includes a fuel tank 50, a fuel supply pipe 51, and a fuel pump 52. At the time of power generation, the fuel supply device 500 drives the fuel pump 52 to supply (pump) the fuel (geic acid aqueous solution) of the power generation flow rate to the fuel electrode 10 toward the fuel inlet 7A. Further, the fuel supply device 500 is also used as a cleaning device, and supplies fuel having a cleaning flow rate, which is a flow rate larger than the generated flow rate, to the fuel electrode 10 to clean the fuel electrode 10. The control device 40 controls the fuel supply device 500 and switches between the operation as the fuel supply device and the operation as the cleaning device. The fuel supply device 500 according to the first embodiment may be referred to as a fuel supply cleaning device.
　燃料電池７Ｘ（７）は、燃料タンク５０からの燃料が流入される燃料流入口７Ａと、使用された燃料を排出する燃料流出口７Ｂとを有し、流入された燃料を用いて発電する。なお、燃料電池７Ｘ（７）の構造の詳細について、以下に説明する。 The fuel cell 7X (7) has a fuel inlet 7A into which fuel from the fuel tank 50 flows in and a fuel outlet 7B in which the used fuel is discharged, and generates electricity using the inflowing fuel. The details of the structure of the fuel cell 7X (7) will be described below.
［燃料電池７Ｘ（７）の構造（図２）］
　燃料電池７Ｘ（７）は、図２に示すように、空気極２０と燃料極１０にて電解質膜３０を挟んだ構成を有している。空気極２０は、空気極触媒層２１、空気極拡散層２２、空気極集電体２３が積層されて構成されている。燃料極１０は、燃料極触媒層１１、燃料極拡散層１２、燃料極集電体１３Ｘ（１３）が積層されて構成されている。 [Structure of fuel cell 7X (7) (Fig. 2)]
As shown in FIG. 2, the fuel cell 7X (7) has a configuration in which the electrolyte membrane 30 is sandwiched between the air electrode 20 and the fuel electrode 10. The air electrode 20 is configured by laminating an air electrode catalyst layer 21, an air electrode diffusion layer 22, and an air electrode current collector 23. The fuel electrode 10 is configured by laminating a fuel electrode catalyst layer 11, a fuel electrode diffusion layer 12, and a fuel electrode current collector 13X (13).
　空気極集電体２３は、厚みが約１～１０［ｍｍ］程度の導電性を有する板状の金属等である。空気極集電体２３には、周囲の空気（酸素）を空気極拡散層２２に流入させる（空気極拡散層２２を外気にさらす）ため、圧送された空気を外部から供給する供給口２３Ａが上方に設けられ、使用された空気と発生する水を回収するため回収孔２３Ｂが下方に設けられている。空気極集電体２３には、図１に示すように、電気負荷（例えば、電動モータ）の一方端が接続される。空気極集電体２３の空気極拡散層２２に接触する側の面には、幅が狭い流路として空気流通溝２３Ｃが形成されている。なお、空気流通溝２３Ｃは、燃料流通溝１３Ｂと同形状に形成しても良い。 The air electrode current collector 23 is a plate-shaped metal or the like having a thickness of about 1 to 10 [mm] and having conductivity. The air electrode current collector 23 has a supply port 23A that supplies pumped air from the outside in order to allow ambient air (oxygen) to flow into the air electrode diffusion layer 22 (expose the air electrode diffusion layer 22 to the outside air). It is provided above, and a recovery hole 23B is provided below to recover the used air and the generated water. As shown in FIG. 1, one end of an electric load (for example, an electric motor) is connected to the air electrode current collector 23. An air flow groove 23C is formed as a narrow flow path on the surface of the air electrode current collector 23 on the side in contact with the air electrode diffusion layer 22. The air flow groove 23C may be formed in the same shape as the fuel flow groove 13B.
　空気極拡散層２２は、厚みが約０．０５～０．５［ｍｍ］程度の層状に形成されている。空気極拡散層２２は、水および空気を透過できるとともに、電子伝導性を有する多孔質材であり、例えば、カーボンペーパーやカーボンクロスを用いることができる。空気極拡散層２２は、空気極集電体２３の供給口２３Ａから流入した空気（酸素）を、拡散させながら空気極触媒層２１に導く。外気の空気に含まれる酸素は、空気極拡散層２２に浸透して空気極触媒層２１の電極触媒粒子に到達する。 The air electrode diffusion layer 22 is formed in a layered shape having a thickness of about 0.05 to 0.5 [mm]. The air electrode diffusion layer 22 is a porous material that can permeate water and air and has electron conductivity, and for example, carbon paper or carbon cloth can be used. The air electrode diffusion layer 22 guides the air (oxygen) that has flowed in from the supply port 23A of the air electrode current collector 23 to the air electrode catalyst layer 21 while diffusing it. Oxygen contained in the outside air permeates the air electrode diffusion layer 22 and reaches the electrode catalyst particles of the air electrode catalyst layer 21.
　空気極触媒層２１は、厚みが約０．０５～０．５［ｍｍ］程度の層状に形成されている。空気極触媒層２１は、空気極の電極触媒粒子（不図示）と、電極触媒粒子を担持する電極触媒担持体（不図示）とを備えている。空気極２０の電極触媒粒子は、空気中の酸素を還元する反応の反応速度を促進させる触媒の粒子であり、例えば白金（Ｐｔ）粒子を用いることができる。電極触媒担持体は、電極触媒粒子を担持できるとともに、導電性を備えるものであればよく、例えばカーボン粉末を用いることができる。燃料としてギ酸を用いた場合、空気極触媒層２１の電極触媒粒子によって、（式１）に示す酸化還元反応が進行する。なお、生成された水（Ｈ2Ｏ）は、図１に示すように、回収孔２３Ｂを介して回収されて回収配管６２を経由して排液タンク６０に導かれる。
　２Ｈ+　＋１／２　Ｏ2　＋２ｅ-　→　Ｈ2Ｏ　　　（式１） The air electrode catalyst layer 21 is formed in a layered shape having a thickness of about 0.05 to 0.5 [mm]. The air electrode catalyst layer 21 includes electrode catalyst particles of air electrodes (not shown) and an electrode catalyst carrier (not shown) that supports the electrode catalyst particles. The electrode catalyst particles of the air electrode 20 are catalyst particles that accelerate the reaction rate of the reaction of reducing oxygen in the air, and for example, platinum (Pt) particles can be used. The electrode catalyst carrier may be any as long as it can support the electrode catalyst particles and has conductivity, for example, carbon powder can be used. When formic acid is used as the fuel, the redox reaction represented by (Equation 1) proceeds by the electrode catalyst particles of the air electrode catalyst layer 21. As shown in FIG. 1, the generated water (H 2 O) is collected through the recovery hole 23B and guided to the drainage tank 60 via the recovery pipe 62.
2H + +1/2 O 2 + 2e - → H 2 O ( Equation 1)
　燃料極集電体１３Ｘ（１３）は、厚みが約１～１０［ｍｍ］程度の導電性を有する板状の金属等である。燃料極集電体１３Ｘ（１３）は、燃料極拡散層１２に接触する燃料流通面１３Ａを有しており、燃料流通面１３Ａには、燃料極拡散層１２の側が開口された燃料流通溝１３Ｂが形成されている。燃料流通溝１３Ｂは、淀みなく燃料が流れるように、幅が狭い流路とされている。また、電子ｅ-を回収するために、燃料流通溝１３Ｂの周囲には、燃料極拡散層１２に接触するランド部１３Ｅが形成されている。燃料極集電体１３Ｘ（１３）には、図１に示すように、電気負荷（例えば、電動モータ）の他方端が接続される。 The fuel electrode current collector 13X (13) is a plate-shaped metal or the like having a thickness of about 1 to 10 [mm] and having conductivity. The fuel electrode current collector 13X (13) has a fuel distribution surface 13A in contact with the fuel electrode diffusion layer 12, and a fuel distribution groove 13B having an opening on the side of the fuel electrode diffusion layer 12 on the fuel distribution surface 13A. Is formed. The fuel flow groove 13B is a narrow flow path so that fuel can flow without stagnation. The electronic e - to recover, on the periphery of the fuel flow channel 13B, the land portion 13E in contact with the fuel electrode diffusing layer 12 is formed. As shown in FIG. 1, the other end of an electric load (for example, an electric motor) is connected to the fuel electrode current collector 13X (13).
　また燃料流通溝１３Ｂは、燃料極集電体１３Ｘ（１３）の一方縁部（または他方縁部）から、対向する他方縁部（または一方縁部）へと略水平方向に延びる複数の流通溝部１３Ｃを有している。また複数の流通溝部１３Ｃのそれぞれは、燃料極集電体１３Ｘ（１３）の一方縁部または他方縁部の近傍に形成されて略鉛直方向に延びる折り返し溝部１３Ｄにて接続されている。また燃料流通溝１３Ｂは、燃料極集電体１３Ｘ（１３）の下方に形成された燃料流入口７Ａと、燃料極集電体１３Ｘ（１３）の上方に形成された燃料流出口７Ｂと、に接続されている。 Further, the fuel flow groove 13B is a plurality of flow groove portions extending in a substantially horizontal direction from one edge portion (or the other edge portion) of the fuel electrode current collector 13X (13) to the opposite edge portion (or one edge portion). It has 13C. Further, each of the plurality of flow groove portions 13C is connected by a folded groove portion 13D formed in the vicinity of one edge portion or the other edge portion of the fuel electrode current collector 13X (13) and extending in a substantially vertical direction. Further, the fuel flow groove 13B has a fuel inlet 7A formed below the fuel electrode current collector 13X (13) and a fuel outlet 7B formed above the fuel electrode current collector 13X (13). It is connected.
　従って、燃料流入口７Ａに流入された燃料は、流通溝部１３Ｃにて一方縁部の側から他方縁部の側へと導かれ、折り返し溝部１３Ｄにて方向転換されて、次の流通溝部１３Ｃにて他方縁部の側から一方縁部の側へと導かれ、次の折り返し溝部１３Ｄにて方向転換されることを繰り返しながら、サーペンタイン型流路とされた燃料流通溝１３Ｂ内を流れ、燃料極拡散層１２中に拡散される。 Therefore, the fuel flowing into the fuel inflow port 7A is guided from the side of one edge portion to the side of the other edge portion by the flow groove portion 13C, is changed in direction by the folded groove portion 13D, and is transferred to the next flow groove portion 13C. It is guided from the other edge side to the one edge side, and while repeating the direction change at the next folded groove portion 13D, it flows through the fuel flow groove 13B which is a serpentine type flow path, and the fuel electrode. It is diffused into the diffusion layer 12.
　燃料極拡散層１２は、厚みが約０．０５～０．５［ｍｍ］程度の層状に形成されている。燃料極拡散層１２は、ギ酸水溶液が内部に浸透できるとともに、電子伝導性を有する多孔質材であり、例えば、カーボンペーパーやカーボンクロスを用いることができる。燃料極拡散層１２は、燃料極集電体１３Ｘ（１３）の燃料流通面１３Ａに形成された燃料流通溝１３Ｂに流される燃料を、拡散させながら燃料極触媒層１１に導く。 The fuel electrode diffusion layer 12 is formed in a layered shape having a thickness of about 0.05 to 0.5 [mm]. The fuel electrode diffusion layer 12 is a porous material that allows an aqueous solution of formic acid to permeate inside and has electron conductivity. For example, carbon paper or carbon cloth can be used. The fuel electrode diffusion layer 12 guides the fuel flowing through the fuel flow groove 13B formed on the fuel flow surface 13A of the fuel electrode current collector 13X (13) to the fuel electrode catalyst layer 11 while diffusing the fuel.
　燃料極触媒層１１は、厚みが約０．０５～０．５［ｍｍ］程度の層状に形成されている。燃料極触媒層１１は、電極触媒粒子（不図示）と、電極触媒粒子を担持する電極触媒担持体（不図示）とを備えている。燃料極１０の電極触媒粒子は、燃料であるギ酸の酸化反応の速度を促進させる触媒の粒子であり、例えばパラジウム（Ｐｄ）粒子を用いることができる。電極触媒担持体は、電極触媒粒子を担持できるとともに、導電性を備えるものであればよく、例えばカーボン粉末を用いることができる。燃料としてギ酸を用いた場合、燃料極触媒層１１の電極触媒粒子によって、（式２）に示す酸化反応が進行する。
　ＨＣＯＯＨ　→　ＣＯ2　＋　２Ｈ+　＋２ｅ-　　　（式２） The fuel electrode catalyst layer 11 is formed in a layered shape having a thickness of about 0.05 to 0.5 [mm]. The fuel electrode catalyst layer 11 includes electrode catalyst particles (not shown) and an electrode catalyst carrier (not shown) that supports the electrode catalyst particles. The electrode catalyst particles of the fuel electrode 10 are catalyst particles that accelerate the rate of oxidation reaction of formic acid, which is a fuel, and for example, palladium (Pd) particles can be used. The electrode catalyst carrier may be any as long as it can support the electrode catalyst particles and has conductivity, for example, carbon powder can be used. When formic acid is used as the fuel, the oxidation reaction shown in (Equation 2) proceeds by the electrode catalyst particles of the fuel electrode catalyst layer 11.
HCOOH → CO 2 + 2H + + 2e - ( Equation 2)
　電解質膜３０は、厚みが約０．０１～０．３［ｍｍ］程度の薄膜状に形成されている。電解質膜３０は、燃料極１０の燃料極触媒層１１と空気極２０の空気極触媒層２１との間に挟まれており、電子伝導性を持たず、水およびＨ+を透過できるプロトン交換膜である。電解質膜３０には、例えば、Ｄｕ　Ｐｏｎｔ社製のＮａｆｉｏｎ（登録商標）等のパーフルオロエチレンスルフォン酸系膜を用いることができる。以上で説明した、燃料極触媒層１１と、燃料極拡散層１２と、電解質膜３０と、空気極触媒層２１と、空気極拡散層２２とが接合されて一体化されたものを、本明細書では、膜／電極接合体（ＭＥＡ；Ｍｅｍｂｒａｎｅ　Ｅｌｅｃｔｒｏｄｅ　Ａｓｓｅｍｂｌｙ）と記載する場合もある。 The electrolyte membrane 30 is formed in the form of a thin film having a thickness of about 0.01 to 0.3 [mm]. The electrolyte membrane 30 is sandwiched between the fuel electrode catalyst layer 11 of the fuel electrode 10 and the air electrode catalyst layer 21 of the air electrode 20, has no electron conductivity, and is a proton exchange membrane capable of transmitting water and H +. Is. As the electrolyte membrane 30, for example, a perfluoroethylene sulfonic acid-based membrane such as Nafion (registered trademark) manufactured by DuPont can be used. The present specification describes the fuel electrode catalyst layer 11, the fuel electrode diffusion layer 12, the electrolyte membrane 30, the air electrode catalyst layer 21, and the air electrode diffusion layer 22 described above, which are joined and integrated. In the document, it may be referred to as a membrane / electrode assembly (MEA; Membrane Electrolyte Assembly).
［燃料電池７Ｘ（７）の作動について］
　ギ酸水溶液は、燃料タンク５０内から燃料供給配管５１に送りだされて、燃料極集電体１３Ｘ（１３）の燃料流入口７Ａから、燃料流通溝１３Ｂに流入する。ギ酸水溶液は、燃料流通溝１３Ｂを流れるにつれ、燃料極拡散層１２に浸透して、燃料極触媒層１１の電極触媒粒子の表面に到達する。そして、燃料極触媒層１１の電極触媒粒子の表面上で、上記の（式２）に示すギ酸の酸化反応が進行する。 [About the operation of fuel cell 7X (7)]
The formic acid aqueous solution is sent from the fuel tank 50 to the fuel supply pipe 51, and flows into the fuel flow groove 13B from the fuel inlet 7A of the fuel electrode current collector 13X (13). As the formic acid aqueous solution flows through the fuel flow groove 13B, it permeates into the fuel electrode diffusion layer 12 and reaches the surface of the electrode catalyst particles of the fuel electrode catalyst layer 11. Then, the oxidation reaction of formic acid represented by the above (formula 2) proceeds on the surface of the electrode catalyst particles of the fuel electrode catalyst layer 11.
　（式２）に示す、ギ酸の酸化反応で生成された二酸化炭素ＣＯ2は、集まって泡となり燃料極１０から排出され、プロトンＨ+は電解質膜３０を透過して空気極触媒層２１の電極触媒粒子に到達する。また、ギ酸から生成された電子ｅ-は、燃料極拡散層１２、燃料極触媒層１１、燃料極集電体１３Ｘ（１３）を流れ、さらに、燃料極集電体１３Ｘ（１３）から外部回路（電気負荷）に流れる。 Carbon dioxide CO 2 produced by the oxidation reaction of formic acid shown in (Equation 2) gathers to form bubbles and is discharged from the fuel electrode 10, and proton H + passes through the electrolyte membrane 30 and permeates the electrode of the air electrode catalyst layer 21. Reach the catalyst particles. The electron generated from formic acid e - the fuel electrode diffusing layer 12, anode catalyst layer 11, the fuel electrode current collector 13X flow (13), further, the external circuit from the fuel electrode current collector 13X (13) Flows to (electric load).
　電子ｅ-は、外部回路（電気負荷）から空気極集電体２３へ流れ、さらに、空気極集電体２３、空気極拡散層２２、空気極触媒層２１を流れて空気極触媒層２１に到達する。空気極触媒層２１の電極触媒粒子表面には、外部回路（電気負荷）からの電子ｅ-と、電解質膜３０を透過したプロトンＨ+と、空気極拡散層２２を透過した外気の酸素とが到達し、上記の（式１）に示す酸化還元反応が進行する。 Electronic e - flows from an external circuit (electrical load) to the air electrode current collector 23, further air electrode current collector 23, the cathode diffusion layer 22, flows through the air electrode catalyst layer 21 to the cathode catalyst layer 21 To reach. The electrode catalyst particle surface of the air electrode catalyst layer 21, electrons e from an external circuit (electrical load) - and the protons H + that passes through the electrolyte membrane 30, the outside air of the oxygen that has passed through the cathode diffusion layer 22 Upon reaching it, the redox reaction represented by the above (formula 1) proceeds.
　以上のように、燃料電池７Ｘ（７）は発電する。そして、燃料極触媒層１１において、（式２）のギ酸の酸化反応で生成される二酸化炭素ＣＯ2は、集まって泡となり、燃料極拡散層１２、燃料流通溝１３Ｂを流れて、燃料流出口７Ｂから排出され、燃料排出配管６１を経由して排液タンク６０に溜められる。 As described above, the fuel cell 7X (7) generates electricity. Then, in the fuel electrode catalyst layer 11, the carbon dioxide CO 2 produced by the oxidation reaction of formic acid of (Equation 2) gathers to form bubbles, flows through the fuel electrode diffusion layer 12 and the fuel flow groove 13B, and flows through the fuel electrode diffusion layer 12 and the fuel flow groove 13B to the fuel outlet. It is discharged from 7B and stored in the drainage tank 60 via the fuel discharge pipe 61.
　ここで、二酸化炭素ＣＯ2は、燃料極触媒層１１の電極触媒粒子表面上で生成されるが、二酸化炭素ＣＯ2が燃料極触媒層１１の電極触媒粒子表面上にとどまると、ギ酸が電極触媒表面に吸着しにくくなるため、（式２）に示すギ酸の酸化反応の進行を阻害する。また、（式２）に示すギ酸の酸化反応の副反応で生成される一酸化炭素ＣＯ等により、燃料極触媒層１１の電極触媒粒子が被毒することによっても、（式２）に示すギ酸の酸化反応の進行が阻害される。 Here, carbon dioxide CO 2 is generated on the surface of the electrode catalyst particles of the fuel electrode catalyst layer 11, but when carbon dioxide CO 2 stays on the surface of the electrode catalyst particles of the fuel electrode catalyst layer 11, formic acid becomes the electrode catalyst. Since it is difficult to be adsorbed on the surface, it inhibits the progress of the oxidation reaction of formic acid shown in (Equation 2). Further, the formic acid shown in (Formula 2) is also caused by poisoning the electrode catalyst particles of the fuel electrode catalyst layer 11 by carbon monoxide CO or the like generated by the side reaction of the oxidation reaction of formic acid shown in (Formula 2). The progress of the oxidation reaction is inhibited.
［第１の実施形態の燃料電池７Ｘ（７）の洗浄処理（図３～図６）］
　図３～図６を用いて、第１の実施形態の燃料電池７Ｘの洗浄処理を説明する。図３は、燃料電池洗浄処理の全体の処理を説明するフローチャートである。図４は、第１の実施形態における燃料供給処理である第１燃料供給処理を説明するフローチャートである。図５は、第１の実施形態における洗浄処理である第１洗浄処理を説明するフローチャートである。図６は、第１の実施形態における燃料供給停止処理を説明するフローチャートである。 [Cleaning process of the fuel cell 7X (7) of the first embodiment (FIGS. 3 to 6)]
The cleaning process of the fuel cell 7X of the first embodiment will be described with reference to FIGS. 3 to 6. FIG. 3 is a flowchart illustrating the entire process of the fuel cell cleaning process. FIG. 4 is a flowchart illustrating a first fuel supply process, which is a fuel supply process according to the first embodiment. FIG. 5 is a flowchart illustrating a first cleaning process, which is a cleaning process according to the first embodiment. FIG. 6 is a flowchart illustrating the fuel supply stop processing in the first embodiment.
　本開示の燃料電池システム１Ｘ（図１参照）が適用されるシステムにおいて、燃料電池システム１Ｘは、発電開始の指示を受けると制御装置４０（図１参照）を起動し、所定間隔（例えば、数１００ｍｓｅｃ）で燃料電池洗浄処理を実行する。以下、図３を用いて、各ステップについて詳細に説明する。 In a system to which the fuel cell system 1X of the present disclosure (see FIG. 1) is applied, the fuel cell system 1X activates the control device 40 (see FIG. 1) upon receiving an instruction to start power generation, and operates at predetermined intervals (for example, a number). The fuel cell cleaning process is executed in 100 msec). Hereinafter, each step will be described in detail with reference to FIG.
　制御装置４０は、起動されると先ず動作モードを発電モードに設定し、燃料電池洗浄処理を開始する。なお、動作モードは、燃料電池システム１Ｘ（１）の動作のモードであり、燃料を供給し燃料電池７Ｘ（７）（図１参照）で発電をさせる発電モードと、発電を停止し燃料極１０（図１参照）を洗浄する洗浄モードと、全ての動作を停止する停止モードからなる。 When the control device 40 is activated, the operation mode is first set to the power generation mode, and the fuel cell cleaning process is started. The operation mode is the operation mode of the fuel cell system 1X (1), and is a power generation mode in which fuel is supplied and the fuel cell 7X (7) (see FIG. 1) generates power, and a power generation mode in which power generation is stopped and the fuel electrode 10 is stopped. It consists of a cleaning mode for cleaning (see FIG. 1) and a stop mode for stopping all operations.
　ステップＳ０１０Ａにて制御装置４０は、動作モードが発電モードであるか否かを判定し、動作モードが発電モードであると判定した場合（Ｙｅｓ）はステップＳ０２０Ａに処理を進め、そうでない場合（Ｎｏ）はステップＳ０１０Ｂに処理を進める。 In step S010A, the control device 40 determines whether or not the operation mode is the power generation mode, and if it is determined that the operation mode is the power generation mode (Yes), the process proceeds to step S020A, and if not (No). ) Proceeds to step S010B.
　ステップＳ０２０Ａにて制御装置４０は、発電時の経過時間が所定経過時間を超えたか否かを判定し、経過時間が所定経過時間を超えたと判定した場合（Ｙｅｓ）はステップＳ０５０Ａに処理を進め、そうでない場合（Ｎｏ）はステップＳ０３０Ａに処理を進める。なお、制御装置４０は、発電開始の指示とともに内部のタイマーを起動しカウントを開始し発電停止の指示とともにカウントを停止する。制御装置４０は、このカウントしたカウント値を積算し、積算したカウント値に基づいて経過時間を求める。所定経過時間は、制御装置４０に予め記憶されており、実験等により決められた値である。所定経過時間は、例えば、数分～数１０分である。 In step S020A, the control device 40 determines whether or not the elapsed time during power generation exceeds the predetermined elapsed time, and if it is determined that the elapsed time exceeds the predetermined elapsed time (Yes), the process proceeds to step S050A. If not, the process proceeds to step S030A. The control device 40 starts an internal timer with an instruction to start power generation, starts counting, and stops counting with an instruction to stop power generation. The control device 40 integrates the counted count values and obtains the elapsed time based on the integrated count values. The predetermined elapsed time is stored in advance in the control device 40 and is a value determined by an experiment or the like. The predetermined elapsed time is, for example, several minutes to several tens of minutes.
　ステップＳ０３０Ａにて制御装置４０は、燃料電池７Ｘの発電電圧を計測し所定電圧よりも小さいか否かを判定し、発電電圧が所定電圧よりも小さいと判定した場合（Ｙｅｓ）はステップＳ０５０Ａに処理を進め、そうでない場合（Ｎｏ）はステップＳ０４０Ａに処理を進める。なお、所定電圧は、制御装置４０に予め記憶されており、清浄時の必要な発電電圧に基づいて決められた値である。例えば、必要な発電電圧が０．８Ｖ～１．０Ｖの場合、所定電圧としては、０．６Ｖ～０．７Ｖである。 In step S030A, the control device 40 measures the generated voltage of the fuel cell 7X and determines whether or not it is smaller than the predetermined voltage. If it is determined that the generated voltage is smaller than the predetermined voltage (Yes), the process proceeds to step S050A. If not (No), the process proceeds to step S040A. The predetermined voltage is stored in advance in the control device 40, and is a value determined based on the power generation voltage required for cleaning. For example, when the required power generation voltage is 0.8V to 1.0V, the predetermined voltage is 0.6V to 0.7V.
　ステップＳ０４０Ａにて制御装置４０は、燃料供給処理（第１燃料供給処理、図４参照）を行い、ステップＳ０１０Ｃに処理を進める。 In step S040A, the control device 40 performs a fuel supply process (first fuel supply process, see FIG. 4), and proceeds to step S010C.
　ステップＳ０５０Ａにて制御装置４０は、動作モードを洗浄モードに設定し、ステップＳ０６０Ａに処理を進める。 In step S050A, the control device 40 sets the operation mode to the cleaning mode, and proceeds to step S060A.
　ステップＳ０６０Ａにて制御装置４０は、経過時間の初期化（積算したカウント値を初期化、ステップＳ０２０Ａ参照）し、ステップＳ０１０Ｃに処理を進める。 In step S060A, the control device 40 initializes the elapsed time (initializes the integrated count value, refer to step S020A), and proceeds to step S010C.
　ステップＳ０１０Ｂにて制御装置４０は、動作モードが洗浄モードであるか否かを判定し、動作モードが洗浄モードであると判定した場合（Ｙｅｓ）はステップＳ０２０Ｂに処理を進め、そうでない場合（Ｎｏ）はステップＳ０４０Ｃに処理を進める。 In step S010B, the control device 40 determines whether or not the operation mode is the cleaning mode, and if the operation mode is determined to be the cleaning mode (Yes), the process proceeds to step S020B, and if not (No). ) Proceeds to step S040C.
　ステップＳ０２０Ｂにて制御装置４０は、洗浄が終了したか否かを判定し、洗浄が終了したと判定した場合（Ｙｅｓ）はステップＳ０５０Ｂに処理を進め、そうでない場合（Ｎｏ）はステップＳ０４０Ｂに処理を進める。なお、制御装置４０は、例えば洗浄の開始とともに内部のタイマーを駆動しカウントを開始し、予め記憶されている所定のカウント値（所定経過時間に相当するカウント値）を超えた場合に洗浄が終了したと判定（洗浄の終了後と判定）する。 In step S020B, the control device 40 determines whether or not the cleaning is completed, and if it is determined that the cleaning is completed (Yes), the process proceeds to step S050B, and if not (No), the process proceeds to step S040B. To proceed. The control device 40 drives, for example, an internal timer at the same time as the start of cleaning to start counting, and when the predetermined count value (count value corresponding to the predetermined elapsed time) stored in advance is exceeded, the cleaning is completed. It is determined that the cleaning has been completed (determined after the cleaning is completed).
　ステップＳ０４０Ｂにて制御装置４０は、洗浄処理（第１洗浄処理、図５参照）を行い、ステップＳ０１０Ｃに処理を進める。 In step S040B, the control device 40 performs a cleaning process (first cleaning process, see FIG. 5), and proceeds to step S010C.
　ステップＳ０５０Ｂにて制御装置４０は、動作モードを発電モードに設定し（発電時に戻す）、ステップＳ０１０Ｃに処理を進める。 In step S050B, the control device 40 sets the operation mode to the power generation mode (returns to the time of power generation), and proceeds to the process in step S010C.
　ステップＳ０４０Ｃにて制御装置４０は、燃料供給停止処理（図６参照）を行い、ステップＳ０１０Ｃに処理を進める。 In step S040C, the control device 40 performs the fuel supply stop processing (see FIG. 6), and proceeds to the processing in step S010C.
　ステップＳ０１０Ｃにて制御装置４０は、発電停止指示が有るか否かを判定し、発電停止指示が有ると判定した場合（Ｙｅｓ）はステップＳ０５０Ｃに処理を進め、そうでない場合（Ｎｏ）は処理を終了する。なお、燃料電池システム１Ｘが適用されるシステムにおいて、制御装置４０は、外部からの停止信号（例えば発電停止スイッチ等）を、あるいは該システムにおける他の装置からの出力信号を、発電停止指示として受け取ることができる。 In step S010C, the control device 40 determines whether or not there is a power generation stop instruction, and if it is determined that there is a power generation stop instruction (Yes), the process proceeds to step S050C, and if not (No), the process is performed. finish. In the system to which the fuel cell system 1X is applied, the control device 40 receives a stop signal from the outside (for example, a power generation stop switch) or an output signal from another device in the system as a power generation stop instruction. be able to.
　ステップＳ０５０Ｃにて制御装置４０は、動作モードを停止モードに設定し、処理を終了する。 In step S050C, the control device 40 sets the operation mode to the stop mode and ends the process.
［第１燃料供給処理（図４）］
　図４は、図３のステップＳ０４０Ａ（燃料供給処理）の詳細を示している。制御装置４０は、燃料電池洗浄処理（図３参照）のステップＳ０４０Ａにて、第１燃料供給処理を行う。具体的には、ステップＳＡ１１０にて、制御装置４０は、燃料供給装置５００の燃料ポンプ５２を駆動して、発電に必要な予め設定されている発電流量の燃料を燃料極１０に供給し、処理を終了する（図１参照）。発電流量は、例えば、３ｍｌ／ｍｉｎである。 [First fuel supply process (Fig. 4)]
FIG. 4 shows the details of step S040A (fuel supply processing) of FIG. The control device 40 performs the first fuel supply process in step S040A of the fuel cell cleaning process (see FIG. 3). Specifically, in step SA110, the control device 40 drives the fuel pump 52 of the fuel supply device 500 to supply the fuel of the preset power generation flow rate required for power generation to the fuel electrode 10 and process it. (See Fig. 1). The power generation flow rate is, for example, 3 ml / min.
［第１洗浄処理（図５）］
　図５は、図３のステップＳ０４０Ｂ（洗浄処理）の詳細を示している。制御装置４０は、燃料電池洗浄処理（図３参照）のステップＳ０４０Ｂにて、第１洗浄処理を行う。具体的には、ステップＳＡ２１０にて、制御装置４０は、燃料供給装置５００の燃料ポンプ５２を駆動して、発電流量よりも多い流量である洗浄流量の燃料を燃料極１０に供給して燃料極１０を洗浄し、処理を終了する。する。なお、洗浄流量は、発電流量よりも多い量であり、例えば、１０ｍｌ／ｍｉｎである。 [First cleaning process (Fig. 5)]
FIG. 5 shows the details of step S040B (cleaning process) of FIG. The control device 40 performs the first cleaning process in step S040B of the fuel cell cleaning process (see FIG. 3). Specifically, in step SA210, the control device 40 drives the fuel pump 52 of the fuel supply device 500 to supply fuel having a cleaning flow rate, which is a flow rate larger than the generated flow rate, to the fuel electrode 10. 10 is washed and the process is completed. To do. The cleaning flow rate is larger than the power generation flow rate, and is, for example, 10 ml / min.
［燃料供給停止処理（図６）］
　図６は、図３のステップＳ０４０Ｃ（燃料供給停止処理）の詳細を示している。制御装置４０は、燃料供給停止処理（図３参照）のステップＳ０４０Ｃにて、燃料供給停止処理を行う。具体的には、ステップＳＡ３１０にて、制御装置４０は、燃料供給装置５００の燃料ポンプ５２を停止して、燃料の供給を停止する。 [Fuel supply stop processing (Fig. 6)]
FIG. 6 shows the details of step S040C (fuel supply stop processing) of FIG. The control device 40 performs the fuel supply stop processing in step S040C of the fuel supply stop processing (see FIG. 3). Specifically, in step SA310, the control device 40 stops the fuel pump 52 of the fuel supply device 500 to stop the fuel supply.
［第２の実施形態の燃料電池システム１Ｙ（１）の構成（図７、図８）］
　図７は、第２の実施形態の燃料電池システム１Ｙ（１）の全体構成を示す図である。図８は、燃料極集電体１３Ｙ（１３）に設けられた流体検知手段７Ｃを説明する断面図である。図７に示すように、燃料電池システム１Ｙは、図１の第１の実施形態の燃料電池システム１Ｘの燃料電池７Ｘの代わりに燃料電池７Ｙと、流体検知手段７Ｃと、燃料開閉弁５３と、洗浄装置７００と、供給開閉弁８２を有している点で相違する。 [Structure of the fuel cell system 1Y (1) of the second embodiment (FIGS. 7 and 8)]
FIG. 7 is a diagram showing the overall configuration of the fuel cell system 1Y (1) of the second embodiment. FIG. 8 is a cross-sectional view illustrating the fluid detecting means 7C provided in the fuel electrode current collector 13Y (13). As shown in FIG. 7, the fuel cell system 1Y includes a fuel cell 7Y, a fluid detection means 7C, a fuel on-off valve 53, and a fuel on-off valve 53 instead of the fuel cell 7X of the fuel cell system 1X of the first embodiment of FIG. It differs from the cleaning device 700 in that it has a supply on-off valve 82.
　図７で示すように、燃料流出口７Ｂは、燃料極１０の上方の側に配置され、燃料流入口７Ａは、燃料極の下方の側に配置されている。燃料流入口７Ａの下方には、燃料または洗浄用流体（純水）を燃料流入口７Ａへ導く流体供給配管８１の一方端が接続されている。また、流体供給配管８１の他方端は、燃料供給配管５１と後述する洗浄流体配管７１にそれぞれ接続されている。 As shown in FIG. 7, the fuel outlet 7B is arranged on the upper side of the fuel electrode 10, and the fuel inlet 7A is arranged on the lower side of the fuel electrode. Below the fuel inlet 7A, one end of a fluid supply pipe 81 that guides fuel or cleaning fluid (pure water) to the fuel inlet 7A is connected. Further, the other end of the fluid supply pipe 81 is connected to the fuel supply pipe 51 and the cleaning fluid pipe 71, which will be described later, respectively.
　また、流体供給配管８１には、流体供給配管８１を開口状態と閉鎖状態に切り替え可能な供給開閉弁８２が設けられている。燃料供給配管５１には、燃料供給配管５１を開口状態と閉鎖状態に切り替え可能な燃料開閉弁５３が設けられている。洗浄流体配管７１には、洗浄流体配管７１を開口状態と閉鎖状態に切り替え可能な洗浄開閉弁７３が設けられている。 Further, the fluid supply pipe 81 is provided with a supply on-off valve 82 capable of switching the fluid supply pipe 81 between an open state and a closed state. The fuel supply pipe 51 is provided with a fuel on-off valve 53 capable of switching the fuel supply pipe 51 between an open state and a closed state. The cleaning fluid pipe 71 is provided with a cleaning on-off valve 73 capable of switching the cleaning fluid pipe 71 between an open state and a closed state.
　図８で示すように、燃料極集電体１３Ｙ（１３）の燃料流出口７Ｂ近傍の流通溝部１３Ｃには、燃料流出口７Ｂを挟んで流体検知手段７Ｃが設けられている。流体検知手段７Ｃは、燃料流入口７Ａ（図７参照）から洗浄用流体ＣＦ（純水）が供給され、下方の側から上方の側へ向けて洗浄用流体ＣＦ（純水）が満たされて、流体検知手段７Ｃまで達すると、洗浄用流体ＣＦ（純水）に応じた信号を制御装置４０へ送信する。流体検知手段７Ｃは、洗浄用流体ＣＦのレベル（純水の場合、水位）を取得できるものであれば良い。 As shown in FIG. 8, a fluid detecting means 7C is provided in the flow groove portion 13C near the fuel outlet 7B of the fuel electrode current collector 13Y (13) with the fuel outlet 7B interposed therebetween. The fluid detecting means 7C is supplied with the cleaning fluid CF (pure water) from the fuel inflow port 7A (see FIG. 7), and is filled with the cleaning fluid CF (pure water) from the lower side to the upper side. When the fluid detecting means 7C is reached, a signal corresponding to the cleaning fluid CF (pure water) is transmitted to the control device 40. The fluid detecting means 7C may be any as long as it can acquire the level (water level in the case of pure water) of the cleaning fluid CF.
　洗浄用流体ＣＦとして純水を用い燃料としてギ酸水溶液を用いた場合、純水とギ酸の物理的・化学的性質の差を利用し、流体検知手段７Ｃとして、種々の検出手段を選択できる。例えば、純水とギ酸水溶液のｐＨの差を利用する場合、流体検知手段７Ｃは、ｐＨメーターを用いることができる。また、純水とギ酸水溶液の抵抗値の差を利用する場合、流体検知手段７Ｃは、抵抗計を用いることができる。 When pure water is used as the cleaning fluid CF and an aqueous solution of formic acid is used as the fuel, various detection means can be selected as the fluid detection means 7C by utilizing the difference in physical and chemical properties between pure water and formic acid. For example, when utilizing the difference in pH between pure water and an aqueous solution of formic acid, the fluid detecting means 7C can use a pH meter. Further, when the difference between the resistance values of pure water and the aqueous solution of formic acid is used, the fluid detecting means 7C can use an ohmmeter.
　図７で示すように、洗浄装置７００は、純水タンク７０（洗浄用流体タンク）と、洗浄流体配管７１と、洗浄流体ポンプ７２と、洗浄開閉弁７３を有している。 As shown in FIG. 7, the cleaning device 700 includes a pure water tank 70 (cleaning fluid tank), a cleaning fluid pipe 71, a cleaning fluid pump 72, and a cleaning on-off valve 73.
　純水タンク７０（洗浄用流体タンク）には、洗浄用流体となる純水が蓄えられている。また純水タンク７０には洗浄流体配管７１の一方端が接続され、洗浄流体配管７１の他方端は流体供給配管８１に接続されている。 The pure water tank 70 (cleaning fluid tank) stores pure water as a cleaning fluid. Further, one end of the cleaning fluid pipe 71 is connected to the pure water tank 70, and the other end of the cleaning fluid pipe 71 is connected to the fluid supply pipe 81.
　洗浄流体ポンプ７２は電動ポンプであり、洗浄流体配管７１に設けられており、純水タンク７０内の純水（洗浄用流体）を燃料電池７Ｙ（７）の燃料流入口７Ａに向けて圧送（供給）する。また、洗浄流体ポンプ７２は、制御装置４０により、圧送する量（供給量）、圧送の開始・停止を制御される。 The cleaning fluid pump 72 is an electric pump, which is provided in the cleaning fluid pipe 71, and pumps pure water (cleaning fluid) in the pure water tank 70 toward the fuel inlet 7A of the fuel cell 7Y (7). Supply). Further, the cleaning fluid pump 72 is controlled by the control device 40 in terms of the amount of pumping (supply amount) and the start / stop of pumping.
［燃料供給装置５００と洗浄装置７００との切替動作（図７、図９～図１３）］
　燃料供給装置５００と洗浄装置７００との切替動作について説明する。図７は、燃料電池７Ｙが発電状態であり、燃料供給装置５００が作動している状態を示している。図９は、燃料電池７Ｙが発電停止状態であり（燃料供給装置５００が停止）、洗浄装置７００が作動している状態を示している。なお、各開閉弁において、流路方向に沿って対向する四半円のそれぞれが黒色の場合、閉鎖状態を示し、黒色でない場合、開口状態を示している。 [Switching operation between the fuel supply device 500 and the cleaning device 700 (FIGS. 7, 9 to 13)]
The switching operation between the fuel supply device 500 and the cleaning device 700 will be described. FIG. 7 shows a state in which the fuel cell 7Y is in a power generation state and the fuel supply device 500 is operating. FIG. 9 shows a state in which the fuel cell 7Y is in the power generation stopped state (the fuel supply device 500 is stopped) and the cleaning device 700 is operating. In each on-off valve, when each of the quadrants facing each other along the flow path direction is black, it indicates a closed state, and when it is not black, it indicates an open state.
　図１０、図１１を用いて、第２の実施形態の燃料電池７Ｙの洗浄処理を説明する。なお、第２の実施形態の全体の処理のフローチャートは図３と同じであり、図３のステップ０４０Ａの処理の詳細は図１０のフローチャートであり、図３のステップ０４０Ｂの処理の詳細は図１１のフローチャートであり、図３のステップ０４０Ｃの処理の詳細は図１３のフローチャートである。 The cleaning process of the fuel cell 7Y of the second embodiment will be described with reference to FIGS. 10 and 11. The flowchart of the entire process of the second embodiment is the same as that of FIG. 3, the details of the process of step 040A of FIG. 3 are the flowchart of FIG. 10, and the details of the process of step 040B of FIG. 3 are shown in FIG. The details of the process of step 040C of FIG. 3 are the flowchart of FIG.
［第２燃料供給処理（図７、図１０）］
　以下、図７と図１０を用いて各ステップについて詳細に説明する。 [Second fuel supply process (Figs. 7 and 10)]
Hereinafter, each step will be described in detail with reference to FIGS. 7 and 10.
　燃料電池洗浄処理のステップＳ０４０Ａ（図３参照）にて制御装置４０は、燃料供給処理（第２燃料供給処理）を実行し、ステップＳＢ１１０に処理を進める。 In step S040A (see FIG. 3) of the fuel cell cleaning process, the control device 40 executes the fuel supply process (second fuel supply process) and proceeds to step SB110.
　ステップＳＢ１１０にて制御装置４０は、燃料開閉弁５３が閉鎖状態、かつ、洗浄開閉弁７３が開口状態であるか否かを判定し、燃料開閉弁５３が閉鎖状態、かつ、洗浄開閉弁７３が開口状態であると判定した場合（Ｙｅｓ）はステップＳＢ１２０に処理を進め、そうでない場合（Ｎｏ）はステップＳＢ１３０に処理を進める。 In step SB110, the control device 40 determines whether or not the fuel on-off valve 53 is in the closed state and the wash on-off valve 73 is in the open state, and the fuel on-off valve 53 is in the closed state and the wash on-off valve 73 is in the open state. If it is determined that the state is open (Yes), the process proceeds to step SB120, and if not (No), the process proceeds to step SB130.
　ステップＳＢ１２０にて制御装置４０は、洗浄装置７００の洗浄流体ポンプ７２の駆動を停止し純水（洗浄用流体）の供給を停止し、ステップＳＢ１３０に処理を進める。 In step SB120, the control device 40 stops driving the cleaning fluid pump 72 of the cleaning device 700, stops the supply of pure water (cleaning fluid), and proceeds to step SB130.
　ステップＳＢ１３０にて制御装置４０は、燃料開閉弁５３を開口状態、かつ、洗浄開閉弁７３が閉鎖状態にし、ステップＳＢ１４０に処理を進める。 In step SB130, the control device 40 closes the fuel on-off valve 53 and the cleaning on-off valve 73, and proceeds to step SB140.
　ステップＳＢ１４０にて制御装置４０は、燃料供給装置５００の燃料ポンプ５２を駆動して、発電流量の燃料を燃料極１０に供給し、処理を終了する（発電時に戻す）。 In step SB140, the control device 40 drives the fuel pump 52 of the fuel supply device 500 to supply the fuel of the generated flow rate to the fuel electrode 10 and end the process (return to the time of power generation).
［第２洗浄処理（図９、図１１）］
　以下、図９と図１１を用いて各ステップについて詳細に説明する。 [Second cleaning process (FIGS. 9 and 11)]
Hereinafter, each step will be described in detail with reference to FIGS. 9 and 11.
　燃料電池洗浄処理のステップＳ０４０Ｂ（図３参照）にて制御装置４０は、洗浄処理（第２洗浄処理）を実行し、ステップＳＢ２１０に処理を進める。 In step S040B (see FIG. 3) of the fuel cell cleaning process, the control device 40 executes the cleaning process (second cleaning process) and proceeds to step SB210.
　ステップＳＢ２１０にて制御装置４０は、燃料開閉弁５３が開口状態、かつ、洗浄開閉弁７３が閉鎖状態であるか否かを判定し、燃料開閉弁５３が開口状態、かつ、洗浄開閉弁７３が閉鎖状態であると判定した場合（Ｙｅｓ）はステップＳＢ２２０に処理を進め、そうでない場合（Ｎｏ）はステップＳＢ２３０に処理を進める。 In step SB210, the control device 40 determines whether or not the fuel on-off valve 53 is in the open state and the wash on-off valve 73 is in the closed state, and the fuel on-off valve 53 is in the open state and the wash on-off valve 73 is in the open state. If it is determined that the state is closed (Yes), the process proceeds to step SB220, and if not (No), the process proceeds to step SB230.
　ステップＳＢ２２０にて制御装置４０は、洗浄装置７００の洗浄流体ポンプ７２の駆動を停止し純水（洗浄用流体）の供給を停止し、ステップＳＢ２３０に処理を進める。 In step SB 220, the control device 40 stops driving the cleaning fluid pump 72 of the cleaning device 700, stops the supply of pure water (cleaning fluid), and proceeds to step SB 230.
　ステップＳＢ２３０にて制御装置４０は、燃料開閉弁５３を閉鎖状態に設定し、かつ、洗浄開閉弁７３が開口状態に設定して、ステップＳＢ２４０に処理を進める。 In step SB230, the control device 40 sets the fuel on-off valve 53 in the closed state and the cleaning on-off valve 73 in the open state, and proceeds to the process in step SB240.
　ステップＳＢ２４０にて制御装置４０は、洗浄装置７００の洗浄流体ポンプ７２を駆動して、純水（洗浄用流体）を燃料極１０に供給して燃料極１０を洗浄し、処理を終了する。 In step SB240, the control device 40 drives the cleaning fluid pump 72 of the cleaning device 700 to supply pure water (cleaning fluid) to the fuel electrode 10 to clean the fuel electrode 10 and end the process.
［腐食乾燥抑制処理（図１２、図１３）］
　図１２の燃料電池システム１Ｙ（１）と図１３のフローチャートを用いて、燃料電池７Ｙ（７）における腐食乾燥抑制処理を説明する。なお、図１２の燃料電池システムは、図７の燃料電池システム１Ｙと同じであるため、構成の詳細な説明は省略する。 [Corrosion drying suppression treatment (FIGS. 12 and 13)]
The corrosion drying suppression process in the fuel cell 7Y (7) will be described with reference to the fuel cell system 1Y (1) of FIG. 12 and the flowchart of FIG. Since the fuel cell system of FIG. 12 is the same as the fuel cell system 1Y of FIG. 7, detailed description of the configuration will be omitted.
　本開示の燃料電池システム１Ｙが適用されるシステムにおいて、燃料電池システム１Ｙは、腐食乾燥抑制処理の指示（例えば、開始スイッチ等からの開始信号）を受けると制御装置４０を起動し、腐食乾燥抑制処理を実行する。以下、図１２と図１３を用いて、各ステップについて詳細に説明する。 In the system to which the fuel cell system 1Y of the present disclosure is applied, the fuel cell system 1Y activates the control device 40 when receiving an instruction for corrosion drying suppression processing (for example, a start signal from a start switch or the like) to suppress corrosion drying. Execute the process. Hereinafter, each step will be described in detail with reference to FIGS. 12 and 13.
　ステップＳＣ０１０にて制御装置４０は、供給開閉弁８２が開口状態であるか否かを判定し、供給開閉弁８２が開口状態であると判定した場合（Ｙｅｓ）はステップＳＣ０２０に処理を進め、そうでない場合（Ｎｏ）はステップＳＣ０１０Ａに処理を進める。 In step SC010, the control device 40 determines whether or not the supply on-off valve 82 is in the open state, and if it is determined that the supply on-off valve 82 is in the open state (Yes), the process proceeds to step SC020. If not (No), the process proceeds to step SC010A.
　ステップＳＣ０１０Ａにて制御装置４０は、供給開閉弁８２を開口状態に設定し、ステップＳＣ０２０に処理を進める。 In step SC010A, the control device 40 sets the supply on-off valve 82 to the open state, and proceeds to the process in step SC020.
　ステップＳＣ０２０にて制御装置４０は、燃料開閉弁５３を閉鎖状態に設定し、かつ、洗浄開閉弁７３が開口状態に設定して、ステップＳＣ０３０に処理を進める。 In step SC020, the control device 40 sets the fuel on-off valve 53 in the closed state and the cleaning on-off valve 73 in the open state, and proceeds to the process in step SC030.
　ステップＳＣ０３０にて制御装置４０は、洗浄装置７００の洗浄流体ポンプ７２を駆動して、純水（洗浄用流体）を燃料極１０に供給して、ステップＳＣ０４０に処理を進める。 In step SC030, the control device 40 drives the cleaning fluid pump 72 of the cleaning device 700 to supply pure water (cleaning fluid) to the fuel electrode 10 and proceed to step SC040.
　ステップＳＣ０４０にて制御装置４０は、燃料極１０が純水（洗浄用流体）で満たされた状態か否かを判定し、燃料極１０が純水（洗浄用流体）で満たされた状態であると判定した場合（Ｙｅｓ）はステップＳＣ０５０に処理を進め、そうでない場合（Ｎｏ）は処理を終了する。なお、制御装置４０は、流体検知手段７Ｃからの信号に基づいて、純水（洗浄用流体）で満たされた状態か否かを判定する。 In step SC040, the control device 40 determines whether or not the fuel electrode 10 is filled with pure water (cleaning fluid), and the fuel electrode 10 is filled with pure water (cleaning fluid). If it is determined (Yes), the process proceeds to step SC050, and if not (No), the process ends. The control device 40 determines whether or not the state is filled with pure water (cleaning fluid) based on the signal from the fluid detecting means 7C.
　ステップＳＣ０５０にて制御装置４０は、洗浄装置７００の洗浄流体ポンプ７２の駆動を停止し純水（洗浄用流体）の供給を停止し、ステップＳＣ０６０に処理を進める。 In step SC050, the control device 40 stops driving the cleaning fluid pump 72 of the cleaning device 700, stops the supply of pure water (cleaning fluid), and proceeds to step SC060.
　ステップＳＣ０６０にて制御装置４０は、供給開閉弁８２を閉鎖状態に設定し、処理を終了する（発電の停止）。 In step SC060, the control device 40 sets the supply on-off valve 82 to the closed state and ends the process (stops power generation).
［本開示に係る効果］
　本開示によれば、燃料電池７の燃料極１０を洗浄することができる。これにより、燃料極１０で発生した副生成物を除去し、燃料電池７の発電電圧の低下を抑制することができる。従って、燃料電池７の発電効率を維持し燃費を向上させることができる。 [Effects of this Disclosure]
According to the present disclosure, the fuel electrode 10 of the fuel cell 7 can be cleaned. As a result, by-products generated at the fuel electrode 10 can be removed, and a decrease in the generated voltage of the fuel cell 7 can be suppressed. Therefore, the power generation efficiency of the fuel cell 7 can be maintained and the fuel efficiency can be improved.
　また、図１に示すように燃料供給装置５００が洗浄装置を兼ねることで洗浄装置を設けることなく燃料供給装置５００のみにより洗浄を行うため、燃料電池システム１（１Ｘ）の構成をシンプルにすることができる。また燃料を用いて燃料極１０を洗浄するため、洗浄処理中であっても発電をすることが可能である。 Further, as shown in FIG. 1, since the fuel supply device 500 also serves as a cleaning device and cleaning is performed only by the fuel supply device 500 without providing the cleaning device, the configuration of the fuel cell system 1 (1X) should be simplified. Can be done. Further, since the fuel electrode 10 is cleaned with fuel, it is possible to generate electricity even during the cleaning process.
　また、燃料電池７の燃料極１０を純水（洗浄用流体）により洗浄するため、副生成物を発生させることなく燃料極１０を洗浄できる。これにより、より清浄に洗浄できるとともに、洗浄時間を短縮することができる。 Further, since the fuel electrode 10 of the fuel cell 7 is cleaned with pure water (cleaning fluid), the fuel electrode 10 can be cleaned without generating by-products. As a result, the cleaning can be performed more cleanly and the cleaning time can be shortened.
　発電停止状態において、燃料極１０を純水で満たすことで乾燥による劣化と燃料極の腐食を防止し、燃料電池７の寿命を延ばすことができる。 By filling the fuel electrode 10 with pure water in the power generation stopped state, deterioration due to drying and corrosion of the fuel electrode can be prevented, and the life of the fuel cell 7 can be extended.
　本開示の、燃料電池システム１は、本実施の形態で説明した構成、構造、形状、外観等に限定されず、本開示の要旨を変更しない範囲で種々の変更、追加、削除が可能である。例えば、図７で示す、燃料電池システム１Ｙにおける燃料開閉弁５３と洗浄開閉弁７３は、必須の構成ではなく燃料ポンプ５２と洗浄流体ポンプ７２のそれぞれにおいて閉鎖状態と開口状態を切り替えても良い。また、同様に、供給開閉弁８２の代わりに、燃料開閉弁５３と洗浄開閉弁７３を同期して閉鎖状態と開口状態を切り替えて流体供給配管８１の閉鎖と開口を行っても良い。 The fuel cell system 1 of the present disclosure is not limited to the configuration, structure, shape, appearance, etc. described in the present embodiment, and various changes, additions, and deletions can be made without changing the gist of the present disclosure. .. For example, the fuel on-off valve 53 and the cleaning on-off valve 73 in the fuel cell system 1Y shown in FIG. 7 are not indispensable configurations, and the closed state and the opening state may be switched between the fuel pump 52 and the cleaning fluid pump 72, respectively. Similarly, instead of the supply on-off valve 82, the fuel on-off valve 53 and the cleaning on-off valve 73 may be synchronously switched between the closed state and the open state to close and open the fluid supply pipe 81.
　また、流体検知手段７Ｃとして、ｐＨメーターと抵抗計を例示したが、燃料（ギ酸水溶液）と洗浄用流体（純水）との間の静電容量の差を検出する静電容量計でも良い。 Further, although a pH meter and an ohmmeter are exemplified as the fluid detecting means 7C, a capacitance meter that detects the difference in capacitance between the fuel (formic acid aqueous solution) and the cleaning fluid (pure water) may also be used.
　洗浄用流体として、純水を使用した例で説明したが、純水の代わりに蒸留水を使用しても良い。また、洗浄用流体を純水又は蒸留水とした場合、燃料電池の発電に伴う廃熱等を利用して熱して、常温よりも高温としたものを用いて洗浄処理をしても良い。 Although the explanation was given with the example of using pure water as the cleaning fluid, distilled water may be used instead of pure water. Further, when the cleaning fluid is pure water or distilled water, the cleaning treatment may be performed using a fluid whose temperature is higher than room temperature by heating using waste heat or the like generated by the power generation of the fuel cell.
　また、他の実施の形態として、図３において、制御装置４０は、ステップＳ０２０Ｂにて洗浄が終了したと判定した後、燃料電池７（図１参照）の発電電圧を計測し、所定電圧よりも小さいと判定した場合、燃料電池７が十分な電力を供給できず寿命に達したと判定し、燃料電池システム１が適用されている上位のシステム（例えば、自動車等）へ異常を知らせる信号を出力するものでも良い。 Further, as another embodiment, in FIG. 3, the control device 40 measures the generated voltage of the fuel cell 7 (see FIG. 1) after determining that the cleaning is completed in step S020B, and is higher than the predetermined voltage. If it is determined that the fuel cell 7 is small, it is determined that the fuel cell 7 cannot supply sufficient power and has reached the end of its life, and a signal for notifying an abnormality is output to a higher-level system (for example, an automobile) to which the fuel cell system 1 is applied. It may be something to do.
　また、以上（≧）、以下（≦）、より大きい（＞）、未満（＜）等は、等号を含んでも含まなくてもよい。また、本実施の形態の説明に用いた数値は一例であり、この数値に限定されるものではない。 Further, the above (≧), the following (≦), the larger (>), the less than (<), etc. may or may not include the equal sign. Further, the numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.
　本出願は、２０１９年１０月１６日出願の日本特許出願特願２０１９-１８９１８０に基づくものであり、その内容はここに参照として取り込まれる。 This application is based on Japanese Patent Application No. 2019-189180 filed on October 16, 2019, the contents of which are incorporated herein by reference.

Claims (5)

  1. 　ギ酸またはアルコールを含む液体を燃料として使用するように構成された直接液体型の燃料電池を有する燃料電池システムにおいて、
    　前記燃料電池は、燃料極と、空気極と、電解質膜とを有し、
    　前記燃料極は、前記燃料が供給される燃料流入口と、前記燃料が排出される燃料流出口とを有し、
    　前記燃料流入口へ向けて前記燃料を供給する、又は、前記燃料流入口へ向けて洗浄用流体を供給し前記燃料極を洗浄する、ように構成された燃料供給洗浄装置と、
    　前記燃料供給洗浄装置による前記燃料の供給と前記燃料極の洗浄とを切り替えるように構成された制御装置と、を備える、
    　燃料電池システム。     In a fuel cell system having a direct liquid fuel cell configured to use a liquid containing formic acid or alcohol as a fuel.
    The fuel cell has a fuel electrode, an air electrode, and an electrolyte membrane.
    The fuel electrode has a fuel inlet to which the fuel is supplied and a fuel outlet to which the fuel is discharged.
    A fuel supply cleaning device configured to supply the fuel toward the fuel inlet or supply a cleaning fluid toward the fuel inlet to clean the fuel electrode.
    A control device configured to switch between the supply of the fuel by the fuel supply cleaning device and the cleaning of the fuel electrode is provided.
    Fuel cell system.
  2. 　請求項１に記載の燃料電池システムであって、
    　前記洗浄用流体は、前記燃料を含み、
    　前記制御装置は、
    　　発電時には、前記燃料供給洗浄装置から、発電流量で前記燃料を前記燃料極に供給し、
    　　前記発電時の経過時間が所定経過時間を超えた場合、または、前記発電時の前記燃料電池の発電電圧が所定電圧よりも小さい場合に、前記発電流量よりも多い流量である洗浄流量で前記燃料を前記燃料極に供給して前記燃料極を洗浄し、
    　　前記洗浄の終了後、前記燃料極に供給される前記燃料の流量を前記洗浄流量から前記発電流量に変更する、
    　ように構成される、
    　燃料電池システム。     The fuel cell system according to claim 1.
    The cleaning fluid contains the fuel and
    The control device is
    At the time of power generation, the fuel is supplied to the fuel electrode from the fuel supply cleaning device at the power generation flow rate.
    When the elapsed time during power generation exceeds a predetermined elapsed time, or when the power generation voltage of the fuel cell during power generation is smaller than the predetermined voltage, the fuel has a wash flow rate that is larger than the power generation flow rate. To the fuel electrode to clean the fuel electrode,
    After the cleaning is completed, the flow rate of the fuel supplied to the fuel electrode is changed from the cleaning flow rate to the power generation flow rate.
    Is configured as
    Fuel cell system.
  3. 　ギ酸またはアルコールを含む液体を燃料として使用するように構成された直接液体型の燃料電池を有する燃料電池システムにおいて、
    　前記燃料電池は、燃料極と、空気極と、電解質膜とを有し、
    　前記燃料極は、前記燃料が供給される燃料流入口と、前記燃料が排出される燃料流出口とを有し、
    　前記燃料流入口へ向けて前記燃料を供給するように構成された燃料供給装置と、
    　前記燃料流入口へ向けて洗浄用流体を供給し前記燃料極を洗浄するように構成された洗浄装置と、
    　前記燃料供給装置による前記燃料の供給と前記洗浄装置による前記燃料極の洗浄とを切り替える制御装置と、を備える、
    　燃料電池システム。     In a fuel cell system having a direct liquid fuel cell configured to use a liquid containing formic acid or alcohol as a fuel.
    The fuel cell has a fuel electrode, an air electrode, and an electrolyte membrane.
    The fuel electrode has a fuel inlet to which the fuel is supplied and a fuel outlet to which the fuel is discharged.
    A fuel supply device configured to supply the fuel to the fuel inlet, and
    A cleaning device configured to supply a cleaning fluid toward the fuel inlet and clean the fuel electrode.
    A control device for switching between supply of the fuel by the fuel supply device and cleaning of the fuel electrode by the cleaning device is provided.
    Fuel cell system.
  4. 　請求項３に記載の燃料電池システムであって、
    　前記洗浄用流体は、純水を含み、
    　前記制御装置は、
    　　発電時には、前記燃料供給装置から、前記燃料を前記燃料極に供給し、
    　　前記発電時の経過時間が所定経過時間を超えた場合、または、前記発電時の前記燃料電池の発電電圧が所定電圧よりも小さい場合に、前記洗浄装置に切り替え、前記洗浄用流体を前記燃料極に供給して前記燃料極を洗浄し、
    　　前記洗浄の終了後、前記燃料供給装置に切り替え、前記燃料を前記燃料極に供給する、
    　ように構成される、
    　燃料電池システム。     The fuel cell system according to claim 3.
    The cleaning fluid contains pure water and contains pure water.
    The control device is
    At the time of power generation, the fuel is supplied to the fuel electrode from the fuel supply device.
    When the elapsed time during power generation exceeds a predetermined elapsed time, or when the generated voltage of the fuel cell during power generation is smaller than the predetermined voltage, the device is switched to the cleaning device, and the cleaning fluid is used as the fuel electrode. To clean the fuel electrode,
    After the cleaning is completed, the fuel supply device is switched to supply the fuel to the fuel electrode.
    Is configured as
    Fuel cell system.
  5. 　請求項４に記載の燃料電池システムであって、
    　前記燃料流出口は、前記燃料極の上方の側に配置され、
    　前記燃料流入口は、前記燃料極の下方の側に配置されており、
    　前記燃料流入口から下方には流体供給配管が配置されており、該流体供給配管が前記燃料及び前記洗浄用流体のうち一方を前記燃料流入口へ導くように、該燃料流入口と接続されており、
    　前記流体供給配管は、前記流体供給配管を開口状態と閉鎖状態に切り替え可能な供給開閉弁を有しており、
    　前記制御装置は、
    　　前記発電時または前記洗浄の際には、前記供給開閉弁を開口状態に制御し、
    　　前記発電を停止させる指示があった場合、
    　　前記洗浄装置に切り替えて、前記洗浄用流体を前記燃料極に供給し、
    　　前記燃料極を前記洗浄用流体で満たした後、前記供給開閉弁を閉鎖状態に制御して、前記発電を停止させる、
    　ように構成される、
    　燃料電池システム。     The fuel cell system according to claim 4.
    The fuel outlet is located on the upper side of the fuel electrode.
    The fuel inlet is located on the lower side of the fuel electrode.
    A fluid supply pipe is arranged below the fuel inlet, and the fluid supply pipe is connected to the fuel inlet so as to guide one of the fuel and the cleaning fluid to the fuel inlet. Ori,
    The fluid supply pipe has a supply on-off valve capable of switching the fluid supply pipe between an open state and a closed state.
    The control device is
    At the time of power generation or cleaning, the supply on-off valve is controlled to be in an open state.
    When instructed to stop the power generation
    Switching to the cleaning device, the cleaning fluid is supplied to the fuel electrode, and the cleaning fluid is supplied to the fuel electrode.
    After filling the fuel electrode with the cleaning fluid, the supply on-off valve is controlled to be closed to stop the power generation.
    Is configured as
    Fuel cell system.
PCT/JP2020/038335 2019-10-16 2020-10-09 Fuel cell system WO2021075381A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002500421A (en) * 1997-12-23 2002-01-08 バラード パワー システムズ インコーポレイティド Method and apparatus for operating an electrochemical fuel cell with periodic fuel starvation at the anode
JP2008084846A (en) * 2006-08-30 2008-04-10 Sanyo Electric Co Ltd Fuel cell and fuel supply device for fuel cell
JP2008192525A (en) * 2007-02-07 2008-08-21 Fujitsu Ltd Fuel cell and its operation method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002500421A (en) * 1997-12-23 2002-01-08 バラード パワー システムズ インコーポレイティド Method and apparatus for operating an electrochemical fuel cell with periodic fuel starvation at the anode
JP2008084846A (en) * 2006-08-30 2008-04-10 Sanyo Electric Co Ltd Fuel cell and fuel supply device for fuel cell
JP2008192525A (en) * 2007-02-07 2008-08-21 Fujitsu Ltd Fuel cell and its operation method

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