WO2013051397A1 - Système de pile à combustible - Google Patents

Système de pile à combustible Download PDF

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Publication number
WO2013051397A1
WO2013051397A1 PCT/JP2012/073980 JP2012073980W WO2013051397A1 WO 2013051397 A1 WO2013051397 A1 WO 2013051397A1 JP 2012073980 W JP2012073980 W JP 2012073980W WO 2013051397 A1 WO2013051397 A1 WO 2013051397A1
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WIPO (PCT)
Prior art keywords
fuel cell
hydrogen concentration
voltage
anode
cell system
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PCT/JP2012/073980
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English (en)
Japanese (ja)
Inventor
充彦 松本
青木　哲也
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日産自動車株式会社
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Publication of WO2013051397A1 publication Critical patent/WO2013051397A1/fr

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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
    • H01M8/04—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
    • H01M8/04761—Pressure; Flow of fuel cell exhausts
    • 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
    • H01M8/0444—Concentration; Density
    • H01M8/04447—Concentration; Density of anode reactants at the inlet or inside the fuel cell
    • 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
    • H01M8/04574—Current
    • H01M8/04589—Current of fuel cell stacks
    • 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
    • H01M8/04634—Other electric variables, e.g. resistance or impedance
    • H01M8/04649—Other electric variables, e.g. resistance or impedance of fuel cell stacks
    • 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
    • H01M8/04753—Pressure; Flow of fuel cell reactants
    • 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
    • H01M8/04—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
    • H01M8/04895—Current
    • H01M8/0491—Current of fuel cell stacks
    • 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

Definitions

  • the present invention relates to a fuel cell system that generates fuel by supplying an anode gas and a cathode gas.
  • JP 2005-310653A discloses a fuel cell system that calculates the hydrogen concentration in the fuel cell stack based on the pressure loss of hydrogen in the anode system and the composition of impure gases such as water vapor and nitrogen.
  • the fuel cell system described above requires a differential pressure gauge for detecting the pressure loss of hydrogen based on the upstream and downstream pressures of the check valve provided in the hydrogen recirculation passage, and calculates the hydrogen concentration.
  • the system configuration is relatively complicated.
  • An object of the present invention is to provide a fuel cell system capable of calculating the hydrogen concentration in the fuel cell with a simple configuration.
  • the phase characteristic calculation unit that calculates the phase characteristic of the internal impedance of the fuel cell based on the output signal of the fuel cell, and the hydrogen concentration in the fuel cell is calculated based on the phase characteristic of the internal impedance And a hydrogen concentration calculation unit.
  • FIG. 1 is a schematic configuration diagram of a fuel cell system according to a first embodiment of the present invention.
  • FIG. 2 is a timing chart for explaining the pulsation operation in the fuel cell system.
  • FIG. 3 is a schematic diagram showing an equivalent circuit of the fuel cell.
  • FIG. 4 is a flowchart of the internal impedance calculation process of the fuel cell stack executed by the controller provided in the fuel cell system.
  • FIG. 5 is a diagram showing the frequency-amplitude characteristics of the inverse notch filter.
  • FIG. 6 is a diagram showing the internal impedance of the fuel cell stack calculated based on the 1 kHz AC output signal on a complex plane.
  • FIG. 7 is a diagram showing the relationship between the hydrogen concentration in the fuel cell stack and the phase delay of the internal impedance.
  • FIG. 1 is a schematic configuration diagram of a fuel cell system according to a first embodiment of the present invention.
  • FIG. 2 is a timing chart for explaining the pulsation operation in the fuel cell system.
  • FIG. 8 is a flowchart showing a hydrogen concentration calculation process executed by the controller.
  • FIG. 9 is a diagram showing the relationship between the phase lag of the AC voltage with respect to the AC current and the hydrogen concentration.
  • FIG. 10 is a flowchart showing an impure gas discharge process executed by the controller.
  • FIG. 11 is a diagram showing the relationship between the hydrogen concentration and the purge valve opening.
  • FIG. 12 is a flowchart showing a hydrogen supply process executed by the controller when the system is started.
  • FIG. 13 is a diagram showing the relationship between the hydrogen concentration and the target anode inlet pressure when the system is started.
  • FIG. 14 is a diagram illustrating the relationship between the hydrogen concentration and the pressure increase rate when the system is started.
  • FIG. 15 is a flowchart showing a hydrogen supply process executed by the controller during power generation after system startup.
  • FIG. 16 is a diagram showing the relationship between the hydrogen concentration during power generation and the target anode inlet lower limit pressure.
  • FIG. 17 is a diagram showing the relationship between the hydrogen concentration during power generation and the anode pressure increase allowance.
  • FIG. 18 is a diagram showing the internal impedance of the fuel cell stack calculated based on the 1 kHz AC output signal on a complex plane.
  • FIG. 19 is a flowchart showing a hydrogen concentration calculation process executed by the controller of the fuel cell system according to the second embodiment of the present invention.
  • FIG. 20 is a diagram showing the relationship between the imaginary part component of the internal impedance of the fuel cell stack and the hydrogen concentration.
  • FIG. 21 is a diagram illustrating the relationship between frequency and alternating current, and the relationship between frequency and alternating voltage.
  • FIG. 22 is a diagram illustrating a calculation result when a phase delay of the AC voltage with respect to the AC current is calculated by performing a Fourier Fourier transform on the AC current and the AC voltage that are output signals of the fuel cell stack.
  • FIG. 23 is a block diagram illustrating a calculation unit included in the controller of the fuel cell system according to the third embodiment of the present invention.
  • FIG. 24 is a diagram schematically illustrating the calculation contents in the division unit, the inverse cosine calculation unit, and the unit conversion gain unit of the calculation unit.
  • FIG. 25 is a diagram illustrating the phase delay of the AC voltage with respect to the AC current calculated by the calculation unit.
  • FIG. 26 is a schematic configuration diagram of an anode gas circulation type fuel cell system.
  • FIG. 27 is a flowchart showing an anode gas circulation process executed by the controller of the anode gas circulation type fuel cell system.
  • FIG. 28 is a diagram showing the relationship between the hydrogen concentration and the circulating pump rotation speed.
  • the fuel cell includes an anode electrode as a fuel electrode, a cathode electrode as an oxidant electrode, and an electrolyte membrane sandwiched between these electrodes.
  • the fuel cell generates electric power using an anode gas containing hydrogen supplied to the anode electrode and a cathode gas containing oxygen supplied to the cathode electrode.
  • the electrochemical reaction that proceeds in both the anode electrode and the cathode electrode is as follows.
  • Anode electrode 2H 2 ⁇ 4H + + 4e ⁇ (1)
  • Cathode electrode 4H + + 4e ⁇ + O 2 ⁇ 2H 2 O (2)
  • the electrochemical reaction of (1) and (2) generates an electromotive force of about 1 V (volt) in the fuel cell.
  • FIG. 1 is a schematic configuration diagram of a fuel cell system 100 according to a first embodiment of the present invention.
  • the fuel cell system 100 includes a fuel cell stack 1, an anode gas supply device 2, a cathode gas supply device 3, a cooling device 4, an inverter 5, a drive motor 6, a battery 7, and a DC / DC converter 8. And a controller 60.
  • the fuel cell stack 1 is configured by stacking a predetermined number of fuel cells 10.
  • the fuel cell stack 1 generates power by receiving supply of hydrogen as an anode gas and air as a cathode gas, and supplies power to various electric devices such as a drive motor 6 that drives a vehicle.
  • the fuel cell stack 1 has an anode side terminal 11 and a cathode side terminal 12 as output terminals for taking out electric power.
  • the anode gas supply device 2 includes a high pressure tank 21, an anode gas supply passage 22, a pressure regulating valve 23, a pressure sensor 24, an anode gas discharge passage 25, a buffer tank 26, a purge passage 27, and a purge valve 28. .
  • the high-pressure tank 21 is a container that stores hydrogen as an anode gas supplied to the fuel cell stack 1 while maintaining the high-pressure state.
  • the anode gas supply passage 22 is a passage for supplying the anode gas discharged from the high-pressure tank 21 to the fuel cell stack 1.
  • One end of the anode gas supply passage 22 is connected to the high-pressure tank 21, and the other end is connected to the anode gas inlet of the fuel cell stack 1.
  • the pressure regulating valve 23 is an electromagnetic valve whose opening degree can be adjusted continuously or stepwise, and is installed in the anode gas supply passage 22.
  • the pressure regulating valve 23 adjusts the high-pressure anode gas discharged from the high-pressure tank 21 to a predetermined pressure.
  • the opening degree of the pressure regulating valve 23 is controlled by the controller 60.
  • the pressure sensor 24 is provided in the anode gas supply passage 22 on the downstream side of the pressure regulating valve 23.
  • the pressure sensor 24 detects the pressure of the anode gas flowing through the anode gas supply passage 22.
  • the pressure of the anode gas detected by the pressure sensor 24 represents the pressure of the entire anode system including the buffer tank 26 and the anode gas flow path inside the fuel cell stack 1.
  • the anode gas discharge passage 25 is a passage that allows the fuel cell stack 1 and the buffer tank 26 to communicate with each other. One end of the anode gas discharge passage 25 is connected to the anode gas outlet of the fuel cell stack 1, and the other end is connected to the upper portion of the buffer tank 26. In the anode gas discharge passage 25, there are excess anode gas that has not been used in the electrochemical reaction and impure gas containing nitrogen, water vapor, or the like that has leaked from the cathode side to the anode gas passage in the fuel cell stack 1. The mixed gas is discharged. This mixed gas is called anode off gas.
  • the buffer tank 26 is a container for temporarily storing the anode off gas flowing through the anode gas discharge passage 25. A part of the water vapor contained in the anode off-gas is condensed in the buffer tank 26 to become condensed water, and is separated from the anode off-gas.
  • the purge passage 27 is a discharge passage that allows the buffer tank 26 to communicate with the outside. One end of the purge passage 27 is connected to the lower portion of the buffer tank 26, and the other end of the purge passage 27 is formed as an open end.
  • the anode off gas stored in the buffer tank 26 is diluted by the cathode off gas flowing into the purge passage 27 from a cathode gas discharge passage 35 (described later), and discharged together with condensed water from the opening end of the purge passage 27 to the outside.
  • the purge valve 28 is an electromagnetic valve whose opening degree can be adjusted continuously or stepwise, and is installed in the purge passage 27. By adjusting the opening of the purge valve 28, the flow rate of the anode off gas discharged from the purge passage 27 to the outside is adjusted. Thus, the purge valve 28 functions as a discharge flow rate adjusting unit that adjusts the flow rate of the anode off gas discharged to the outside.
  • the opening degree of the purge valve 28 is controlled by the controller 60.
  • the cathode gas supply device 3 includes a cathode gas supply passage 31, a filter 32, a compressor 33, a pressure sensor 34, a cathode gas discharge passage 35, and a pressure regulating valve 36.
  • the cathode gas supply passage 31 is a passage through which air that is cathode gas supplied to the fuel cell stack 1 flows. One end of the cathode gas supply passage 31 is connected to the filter 32, and the other end is connected to the cathode gas inlet of the fuel cell stack 1.
  • the filter 32 removes foreign matters such as dust and dust contained in the air taken in from the outside.
  • the air from which the foreign matter has been removed by the filter 32 becomes the cathode gas supplied to the fuel cell stack 1.
  • the compressor 33 is installed in the cathode gas supply passage 31 between the filter 32 and the fuel cell stack 1.
  • the compressor 33 pumps the cathode gas taken in through the filter 32 to the fuel cell stack 1.
  • the pressure sensor 34 is provided in the cathode gas supply passage 31 on the downstream side of the compressor 33.
  • the pressure sensor 34 detects the pressure of the cathode gas flowing through the cathode gas supply passage 31.
  • the pressure of the cathode gas detected by the pressure sensor 34 represents the pressure of the entire cathode system including the cathode gas flow path and the like inside the fuel cell stack 1.
  • the cathode gas discharge passage 35 is a passage that communicates the fuel cell stack 1 and the purge passage 27 of the anode gas supply device 2. One end of the cathode gas discharge passage 35 is connected to the cathode gas outlet of the fuel cell stack 1, and the other end is connected to the purge passage 27 on the downstream side of the purge valve 28.
  • the cathode gas that has not been used for the electrochemical reaction in the fuel cell stack 1 is discharged to the purge passage 27 via the cathode gas discharge passage 35 as a cathode off gas.
  • the pressure regulating valve 36 is an electromagnetic valve whose opening degree can be adjusted continuously or stepwise, and is installed in the cathode gas discharge passage 35.
  • the opening of the pressure regulating valve 36 is controlled by the controller 60 to adjust the pressure of the cathode gas supplied to the fuel cell stack 1.
  • the cooling device 4 is a device for cooling the fuel cell stack 1 with cooling water.
  • the cooling device 4 includes a cooling water circulation passage 41, a cooling water circulation pump 42, a radiator 43, and cooling water temperature sensors 44 and 45.
  • the cooling water circulation passage 41 is a passage through which cooling water for cooling the fuel cell stack 1 flows. One end of the coolant circulation passage 41 is connected to the coolant inlet portion of the fuel cell stack 1, and the other end is connected to the coolant outlet portion of the fuel cell stack 1.
  • the cooling water circulation pump 42 is a pressure feeding device that circulates the cooling water, and is installed in the cooling water circulation passage 41.
  • the radiator 43 is a radiator for cooling the cooling water discharged from the fuel cell stack 1 and is installed in the cooling water circulation passage 41 on the upstream side of the cooling water circulation pump 42.
  • the cooling water temperature sensors 44 and 45 are sensors that detect the temperature of the cooling water.
  • the cooling water temperature sensor 44 is provided in the cooling water circulation passage 41 near the cooling water inlet of the fuel cell stack 1 and detects the temperature of the cooling water flowing into the fuel cell stack 1.
  • the cooling water temperature sensor 45 is provided in the cooling water circulation passage 41 near the cooling water outlet of the fuel cell stack 1 and detects the temperature of the cooling water discharged from the fuel cell stack 1.
  • the inverter 5 includes a switch unit 51 and a smoothing capacitor 52 and is electrically connected to the fuel cell stack 1 via the anode side terminal 11 and the cathode side terminal 12.
  • the switch unit 51 includes a plurality of switching elements, and converts direct current into alternating current or alternating current into direct current.
  • the smoothing capacitor 52 is connected in parallel to the fuel cell stack 1 and suppresses ripples caused by switching or the like in the switch unit 51.
  • the drive motor 6 is a three-phase AC motor, and is actuated by an AC current supplied from the inverter 5 to generate torque for driving the vehicle.
  • the battery 7 is electrically connected to the drive motor 6 and the fuel cell stack 1 via the DC / DC converter 8.
  • the battery 7 is a chargeable / dischargeable secondary battery such as a lithium ion secondary battery.
  • the DC / DC converter 8 is electrically connected to the fuel cell stack 1.
  • the DC / DC converter 8 is a bidirectional voltage converter that raises and lowers the voltage of the fuel cell stack 1.
  • the DC / DC converter 8 converts a direct current input voltage into an arbitrary direct current output voltage.
  • the controller 60 is a microcomputer including a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface).
  • the controller 60 includes a current sensor 61 that detects the output current of the fuel cell stack 1 and a voltage sensor 62 that detects the output voltage of the fuel cell stack 1.
  • Detection signals from an accelerator pedal sensor 63 that detects the amount of depression of an accelerator pedal provided in the vehicle and an SOC sensor 64 that detects the amount of charge of the battery 7 are input as signals for detecting the operating state of the fuel cell system 100. .
  • the controller 60 performs pulsation operation that periodically opens and closes the pressure regulating valve 23 based on these input signals to periodically increase and decrease the anode pressure.
  • the fuel cell stack 1 is not discharged. Since the anode off gas containing the used anode gas continues to be discharged to the outside through the purge passage 27, the anode gas is wasted.
  • a pulsation operation is performed in which the pressure regulating valve 23 is periodically opened and closed to periodically increase and decrease the anode pressure.
  • the anode off gas accumulated in the buffer tank 26 can be caused to flow back to the fuel cell stack 1 when the anode pressure is reduced.
  • the anode gas in the anode off gas can be reused, the amount of the anode gas discharged to the outside can be reduced, and waste can be eliminated.
  • FIG. 2 is a diagram for explaining pulsation operation during steady operation of the fuel cell system 100.
  • the controller 60 calculates the target output of the fuel cell stack 1 based on the operating state of the fuel cell system 100, and sets the upper limit value and the lower limit value of the anode pressure according to the target output. To do. Then, the anode pressure is periodically increased or decreased between the upper limit value and the lower limit value of the set anode pressure.
  • the pressure regulating valve 23 is opened to an opening at which at least the anode pressure can be increased to the upper limit.
  • anode gas is supplied from the high-pressure tank 21 to the fuel cell stack 1, and anode off-gas is discharged to the buffer tank 26.
  • the pressure regulating valve 23 is closed as shown in FIG. 2B, and the supply of anode gas from the high-pressure tank 21 to the fuel cell stack 1 is stopped. Then, the anode gas left in the anode gas flow path in the fuel cell stack 1 is consumed over time due to the electrochemical reaction (1) described above, and the anode pressure is reduced by the amount of consumption of the anode gas.
  • the pressure in the buffer tank 26 temporarily becomes higher than the pressure in the anode gas flow path of the fuel cell stack 1.
  • the anode off-gas flows back into.
  • the anode gas left in the anode gas flow path of the fuel cell stack 1 and the anode gas in the anode off-gas flowing backward from the buffer tank 26 are consumed over time.
  • the pressure regulating valve 23 When the anode pressure reaches the lower limit value at time t3, the pressure regulating valve 23 is opened in the same manner as at time t1. When the anode pressure reaches the upper limit again at time t4, the pressure regulating valve 23 is closed. In this way, the pulsation operation is performed by periodically opening and closing the pressure regulating valve 23.
  • the fuel cell system 100 described above calculates the internal impedance of the fuel cell stack 1 (internal impedance of the electrolyte membrane of the fuel cell 10) in order to maintain the system operating state normally, and the water content (fuel content of the fuel cell stack 1) The wetness of the electrolyte membrane of the battery 10 is managed.
  • the fuel cell system 100 calculates the anode gas concentration (hydrogen concentration) in the fuel cell stack 1 and manages the accumulation state of impure gas in the anode system.
  • FIG. 3 is a schematic diagram showing an equivalent circuit of the fuel cell.
  • FIG. 4 is a flowchart of the internal impedance calculation process of the fuel cell stack 1 executed by the controller 60.
  • FIG. 5 is a diagram showing the frequency-amplitude characteristics of the inverse notch filter.
  • the equivalent circuit of the fuel cell includes membrane resistance Rmem, charge transfer resistance Ra and electric double layer capacitance Ca on the anode electrode side, charge transfer resistance Rc and electric double layer capacitance Cc on the cathode electrode side. It is expressed using.
  • the amount of platinum supported on the catalyst layer of the anode electrode is smaller than the amount of platinum supported on the catalyst layer of the cathode electrode, and the electric double layer capacity Ca on the anode side is the cathode. It is set smaller than the electric double layer capacitance Cc on the side.
  • the combined impedance of the charge transfer resistance Ra and the electric double layer capacitance Ca, the charge transfer resistance Rc, and the electric double layer The composite impedance of the capacitor Cc can be ignored, and the membrane resistance Rmem of the fuel cell, that is, the internal impedance Z of the fuel cell can be calculated by dividing the voltage amplitude value ⁇ V by the current amplitude value ⁇ I.
  • the internal impedance calculation process executed by the controller 60 of the fuel cell system 100 will be described.
  • the internal impedance calculation process of the fuel cell stack 1 is based on the conventionally known AC impedance method.
  • the internal impedance calculation process is executed at a predetermined timing that requires calculation of the internal impedance of the fuel cell stack 1.
  • step 101 (S101) the controller 60 sets, as the current target fuel cell voltage, a value obtained by adding an alternating voltage of 1 kHz to the target fuel cell voltage of the fuel cell stack 1 set according to the vehicle operating state.
  • the controller 60 controls the DC / DC converter 8 so as to be the target fuel cell voltage set in S101.
  • the output signal of the fuel cell stack 1 becomes an alternating voltage and an alternating current including a frequency of 1 kHz.
  • the controller 60 detects the output current of the fuel cell stack 1 using the current sensor 61, and detects the output voltage of the fuel cell stack 1 using the voltage sensor 62.
  • the controller 60 extracts the 1 kHz component of the alternating current value and the alternating voltage value detected in S103 using an inverse notch filter, and calculates the alternating current value and the alternating voltage value at 1 kHz.
  • the inverse notch filter is a filter having frequency-amplitude characteristics in which the passband center is set to 1 kHz.
  • the controller 60 calculates the integrated current value by integrating the absolute value of the alternating current value for 100 ms.
  • the controller 60 calculates the voltage integrated value by integrating the absolute value of the AC voltage value for 100 ms.
  • the controller 60 divides the voltage integrated value calculated in S106 by the current integrated value calculated in S105, calculates the internal impedance Z of the fuel cell stack 1, and ends the internal impedance calculation process.
  • the present applicant has found that there is a correlation as shown in FIGS. 6 and 7 between the internal impedance Z of the fuel cell stack 1 calculated as described above and the hydrogen concentration in the fuel cell stack 1. It was.
  • the hydrogen concentration in the fuel cell stack 1 is the ratio of hydrogen contained in the gas existing in the anode system inside the fuel cell stack 1.
  • FIG. 6 is a diagram showing the internal impedance of the fuel cell stack 1 calculated based on the 1 kHz AC output signal on a complex plane.
  • the horizontal axis is the real part of the internal impedance, and the vertical axis is the imaginary part of the internal impedance.
  • FIG. 7 is a diagram showing the relationship between the hydrogen concentration in the fuel cell stack 1 and the phase delay ⁇ of the internal impedance.
  • phase delay ⁇ of the AC voltage with respect to the output AC current that is, the so-called internal impedance phase delay increases.
  • This phase lag is caused by a decrease in the hydrogen concentration in the fuel cell stack 1, which increases the charge transfer resistance Ra on the anode electrode side in FIG. 3 and causes an alternating current to flow through the electric double layer capacitance Ca. This is caused by a decrease in the combined value of the double layer capacities Ca and Cc.
  • the hydrogen concentration in the fuel cell stack 1 is calculated by utilizing the correlation between the phase delay of the internal impedance of the fuel cell stack 1 and the hydrogen concentration in the fuel cell stack 1.
  • FIG. 8 is a flowchart showing a hydrogen concentration calculation process executed by the controller 60.
  • FIG. 9 is a diagram showing the relationship between the phase lag of the AC voltage with respect to the AC current at 1 kHz and the hydrogen concentration.
  • the hydrogen concentration calculation process shown in FIG. 8 is executed after the internal impedance calculation process or at a predetermined timing when the hydrogen concentration needs to be calculated.
  • the controller 60 controls the DC / DC converter 8 so that the output signal of the fuel cell stack 1 includes an AC signal of 1 kHz, detects the AC current by the current sensor 61, and generates the AC voltage by the voltage sensor 62. To detect.
  • the controller 60 performs a Fourier transform process on the detected alternating current value to calculate the phase angle of the alternating current at 1 kHz.
  • the controller 60 performs a Fourier transform process on the detected AC voltage value to calculate the phase angle of the AC voltage at 1 kHz.
  • the controller 60 calculates the phase delay ⁇ of the AC voltage with respect to the AC current based on the calculated phase angle of the AC current and the phase angle of the AC voltage.
  • the phase delay ⁇ of the AC voltage with respect to the AC current corresponds to the phase delay of the internal impedance of the fuel cell stack 1.
  • the controller 60 refers to the phase delay ⁇ -hydrogen concentration characteristic shown in FIG. 9 and calculates the hydrogen concentration in the fuel cell stack 1 based on the phase delay ⁇ of the AC voltage with respect to the AC current calculated in S204. Then, the hydrogen concentration calculation process is terminated.
  • the phase lag ⁇ -hydrogen concentration characteristic in FIG. 9 is preset data used for calculating the hydrogen concentration in the fuel cell stack 1, and is stored in the ROM of the controller 60.
  • the phase delay ⁇ -hydrogen concentration characteristic is set so that the hydrogen concentration increases as the phase delay ⁇ of the AC voltage with respect to the AC current decreases.
  • FIG. 10 is a flowchart showing an impure gas discharge process executed by the controller 60.
  • FIG. 11 is a diagram showing the relationship between the hydrogen concentration and the purge valve opening.
  • the impure gas discharge process shown in FIG. 10 is executed, for example, at a cycle of 100 microseconds from when the ignition switch is turned on until it is turned off.
  • the controller 60 refers to the hydrogen concentration-purge valve opening characteristic shown in FIG. 11, and determines the opening of the purge valve 28 based on the hydrogen concentration in the fuel cell stack 1 calculated by the hydrogen concentration calculation processing. To do.
  • the hydrogen concentration-purge valve opening characteristic in FIG. 11 is preset data used for determining the opening degree of the purge valve 28, and is stored in the ROM of the controller 60.
  • the hydrogen concentration-purge valve opening characteristic is set such that the opening of the purge valve 28 increases as the hydrogen concentration decreases.
  • As the hydrogen concentration in the fuel cell stack 1 decreases it is presumed that more impurity gas such as nitrogen is present in the fuel cell stack 1, so the opening of the purge valve 28 is increased and discharged to the outside. By increasing the flow rate of the anode off gas, it is possible to prevent the impure gas from flowing backward from the buffer tank 26 into the fuel cell stack 1.
  • the controller 60 controls the purge valve 28 to achieve the opening determined in S301, and ends the impure gas discharge process.
  • the impure gas discharge process described above can prevent a decrease in the hydrogen concentration of the anode system in the fuel cell stack 1 and suppress the deterioration of the power generation efficiency of the fuel cell stack 1.
  • FIG. 12 is a flowchart showing a hydrogen supply process at the time of system startup executed by the controller 60.
  • FIG. 13 is a diagram showing the relationship between the hydrogen concentration and the target anode inlet pressure when the system is started.
  • FIG. 14 is a diagram illustrating the relationship between the hydrogen concentration and the pressure increase rate when the system is started.
  • the hydrogen supply process at the time of starting the system shown in FIG. 12 is executed when the ignition switch is turned on and the fuel cell system starts (starts up).
  • the controller 60 sets a pressure condition (anode gas pressure condition) of hydrogen supplied to the fuel cell stack 1 when the system is started.
  • the controller 60 refers to the hydrogen concentration-target anode inlet pressure characteristic shown in FIG. 13 and determines the target anode inlet pressure based on the hydrogen concentration calculated at the time of starting the system.
  • the target anode inlet pressure is a hydrogen supply pressure at the anode gas inlet of the fuel cell stack 1. Note that the hydrogen concentration calculated at the time of starting the system is the hydrogen concentration before the anode gas is supplied to the fuel cell stack 1.
  • the hydrogen concentration-target anode inlet pressure characteristic in FIG. 13 is preset data used for determining the target anode inlet pressure, and is stored in the ROM of the controller 60.
  • the hydrogen concentration-target anode inlet pressure characteristic is set so that the target anode inlet pressure increases as the hydrogen concentration at the start of the system decreases.
  • the target anode inlet pressure is set to a predetermined maximum pressure.
  • the controller 60 refers to the hydrogen concentration-pressure increase rate characteristic shown in FIG. 14, and determines the pressure increase rate based on the hydrogen concentration calculated at the time of starting the system.
  • the hydrogen concentration-pressure increase rate characteristic of FIG. 14 is preset data used for determining the increase rate when the anode pressure is increased to the target anode inlet pressure, and is stored in the ROM of the controller 60. ing.
  • the hydrogen concentration-pressure increase rate characteristic is set so that the pressure increase rate increases as the hydrogen concentration at the start of the system decreases.
  • the pressure increase speed is set to a predetermined maximum speed.
  • the controller 60 performs PID control of the pressure regulating valve 23 so that the anode pressure detected by the pressure sensor 24 increases to the target anode inlet pressure determined in S402 at the pressure increase rate determined in S403, The hydrogen supply process at the time of starting the system is terminated.
  • the catalyst on the cathode side may deteriorate due to a so-called hydrogen front.
  • the anode system is filled with air when the system is started, that is, when the hydrogen concentration in the fuel cell stack 1 is low, the target anode inlet pressure is increased and the pressure increase rate is increased. Since the speed is increased, the air remaining in the fuel cell stack 1 can be discharged to the buffer tank 26 by the strong flow of the anode gas. As a result, it is possible to suppress the generation of hydrogen front in the fuel cell stack 1 when the system is started.
  • FIG. 15 is a flowchart showing a hydrogen supply process executed by the controller 60 of the fuel cell system 100 during power generation after the system is started.
  • FIG. 16 is a diagram showing the relationship between the hydrogen concentration and the target anode inlet lower limit pressure during power generation after system startup.
  • FIG. 17 is a diagram illustrating the relationship between the hydrogen concentration and the anode pressure increase allowance during power generation after system startup.
  • the fuel cell system 100 executes the hydrogen supply process shown in FIG. 15 instead of the hydrogen supply process shown in FIG.
  • the controller 60 sets a pressure condition (anode gas pressure condition) of hydrogen supplied to the fuel cell stack 1 in S501 and S502.
  • the controller 60 refers to the hydrogen concentration-target anode inlet lower limit pressure characteristic shown in FIG. 16, and determines the target anode inlet lower limit pressure based on the hydrogen concentration calculated during power generation after the system is started.
  • the target anode inlet lower limit pressure is the minimum anode pressure necessary for running the vehicle.
  • the hydrogen concentration-target anode inlet lower limit pressure characteristic in FIG. 16 is preset data used for determining the target anode inlet lower limit pressure, and is stored in the ROM of the controller 60.
  • the hydrogen concentration-target anode inlet lower limit pressure characteristic is set such that the target anode inlet lower limit pressure increases as the hydrogen concentration decreases. Further, the hydrogen concentration-target anode inlet lower limit pressure characteristic is set for each required output current to the fuel cell stack 1, and is set so that the target anode inlet lower limit pressure at the same hydrogen concentration increases as the required output current increases. Has been.
  • the target anode inlet pressure is set to a predetermined maximum pressure based on the hydrogen concentration-target anode inlet lower limit pressure characteristic determined by the required output current.
  • the target anode inlet pressure is set to a predetermined minimum pressure based on the hydrogen concentration-target anode inlet lower limit pressure characteristic determined by the required output current.
  • the controller 60 refers to the required output current-anode pressure increase allowance characteristic shown in FIG. 17 and determines the anode pressure increase allowance based on the required output current for the fuel cell stack 1.
  • the anode pressure increase allowance is a value indicating the amount of pressure increase from the target anode inlet lower limit pressure.
  • the required output current for the fuel cell stack 1 is calculated by the controller 60 based on the detection value of the accelerator pedal sensor 63.
  • the controller 60 includes a required output current calculation unit.
  • the required output current-anode pressure increase allowance characteristic in FIG. 17 is preset data used to determine the anode pressure increase allowance, and is stored in the ROM of the controller 60.
  • the required output current-anode pressure increase allowance characteristic is set so that the anode pressure increase allowance increases as the required output current increases.
  • the controller 60 PID-controls the pressure regulating valve 23 so that the anode pressure detected by the pressure sensor 24 increases to the target anode inlet lower limit pressure plus the anode pressure increase allowance, and performs hydrogen supply processing. finish.
  • the target anode inlet lower limit pressure is set according to the required output current and the hydrogen concentration in the fuel cell stack 1, and the anode pressure increase margin is set according to the required output current. Therefore, it is possible to prevent a shortage of hydrogen concentration in the fuel cell stack 1 during power generation. Thereby, it becomes possible to suppress deterioration of the fuel cell stack 1 due to insufficient hydrogen concentration.
  • the hydrogen concentration in the fuel cell stack 1 is calculated using the phase characteristic of the internal impedance of the fuel cell stack 1 that is correlated with the hydrogen concentration in the fuel cell stack 1. Specifically, the fuel cell stack 1 is controlled so that the output signal of the fuel cell stack 1 becomes an AC signal including a predetermined frequency, and the phase delay of the AC voltage with respect to the AC current output from the fuel cell stack 1 is calculated. The hydrogen concentration in the fuel cell stack 1 is calculated based on the phase delay of the AC voltage with respect to the AC current. By calculating the hydrogen concentration based on the alternating current and the alternating voltage used for measuring the internal impedance of the fuel cell stack 1 in this way, it is possible to calculate the hydrogen concentration with a simpler configuration than in the past. .
  • the fuel cell system 100 according to the second embodiment is different from the fuel cell system according to the first embodiment in that the hydrogen concentration is calculated based on the imaginary part component of the internal impedance of the fuel cell stack 1.
  • the difference will be mainly described.
  • FIG. 18 is a diagram showing the internal impedance of the fuel cell stack 1 calculated based on the 1 kHz AC output signal on a complex plane.
  • the phase delay of the AC voltage with respect to the AC current is regarded as the phase delay of the internal impedance.
  • the imaginary part component Zim of the internal impedance is regarded as the phase delay of the internal impedance.
  • the hydrogen concentration of the fuel cell stack 1 is calculated using the imaginary part component Zim of the internal impedance that correlates with the phase delay ⁇ of the internal impedance.
  • FIG. 19 is a flowchart showing a hydrogen concentration calculation process executed by the controller 60 of the fuel cell system 100 according to the second embodiment.
  • FIG. 20 is a diagram showing the relationship between the imaginary part component Zim of the internal impedance of the fuel cell stack 1 and the hydrogen concentration. 19 and 20 replace FIG. 8 and FIG. 9 described in the first embodiment.
  • the hydrogen concentration calculation process shown in FIG. 19 is executed after the internal impedance calculation process or at a predetermined timing when the hydrogen concentration needs to be calculated.
  • the controller 60 controls the DC / DC converter 8 so that the output signal of the fuel cell stack 1 includes an AC signal of 1 kHz, detects the AC current by the current sensor 61, and generates the AC voltage by the voltage sensor 62. To detect.
  • the controller 60 performs a Fourier transform process on the detected alternating current value to calculate an imaginary part component of the amplitude of the alternating current at 1 kHz.
  • the controller 60 performs a Fourier transform process on the detected AC voltage value to calculate an imaginary part component of the amplitude of the AC voltage at 1 kHz.
  • the controller 60 calculates the imaginary part component Zim of the internal impedance of the fuel cell stack 1 by dividing the imaginary part of the AC voltage amplitude by the imaginary part of the AC current amplitude. There is a correlation between the imaginary part component Zim of the internal impedance of the fuel cell stack 1 and the phase delay of the internal impedance of the fuel cell stack 1.
  • the controller 60 refers to the imaginary part component-hydrogen concentration characteristic of the internal impedance shown in FIG. 20, and calculates the hydrogen concentration in the fuel cell stack 1 based on the imaginary part component Zim of the internal impedance calculated in S208. Then, the hydrogen concentration calculation process is terminated.
  • the imaginary part component-hydrogen concentration characteristic of the internal impedance in FIG. 20 is preset data used to calculate the hydrogen concentration in the fuel cell stack 1, and is stored in the ROM of the controller 60. Yes.
  • the imaginary part component-hydrogen concentration characteristic of the internal impedance is set so that the hydrogen concentration increases as the imaginary part component Zim of the internal impedance of the fuel cell stack 1 decreases.
  • the fuel cell stack 1 is controlled so that the output signal of the fuel cell stack 1 becomes an AC signal including a predetermined frequency, and the AC current output from the fuel cell stack 1 and An imaginary part component Zim of the internal impedance is calculated based on the AC voltage, and a hydrogen concentration in the fuel cell stack 1 is calculated based on the imaginary part component Zim of the internal impedance.
  • a fuel cell system 100 according to a third embodiment of the present invention will be described with reference to FIGS.
  • the fuel cell system 100 according to the third embodiment differs from the fuel cell system according to the first embodiment in the method of calculating the phase delay of the AC voltage with respect to the AC current.
  • the difference will be mainly described.
  • the fuel cell stack 1 is controlled so that the output signal of the fuel cell stack 1 becomes an AC signal including a frequency of 1 kHz, and the phase delay of the AC voltage with respect to the AC current is calculated.
  • the hydrogen concentration is calculated based on the phase delay.
  • the alternating current is caused by control errors by the DC / DC converter 8, detection errors by the current sensor 61 and the voltage sensor 62, and the like.
  • the frequency of the current and the AC voltage may deviate from the set frequency of 1 kHz as shown in FIGS. 21 (A) and 21 (B).
  • FIG. 22 is a diagram showing a calculation result when the phase lag of the AC voltage with respect to the AC current is calculated by subjecting the AC current and the AC voltage, which are output signals of the fuel cell stack 1, to division Fourier transform.
  • a solid line A indicates a case where the frequencies of the alternating current and the alternating voltage are not deviated from the set frequency.
  • a broken line B indicates a case where the frequencies of the alternating current and the alternating voltage are shifted from the set frequency by 0.5 Hz.
  • An alternate long and short dash line C indicates a case where the frequencies of the alternating current and the alternating voltage are shifted by 1.0 Hz from the set frequency.
  • the phase delay of the alternating voltage with respect to the alternating current converges to a true value, for example, 10 °, but the frequency of the alternating current and the alternating voltage is the set frequency.
  • the phase delay of the AC voltage with respect to the AC current becomes a value deviated from the true value as the calculation time becomes longer. If the hydrogen concentration is calculated based on the phase lag that deviates from the true value in this way, the calculation accuracy of the hydrogen concentration deteriorates.
  • the above-described decrease in calculation accuracy of the phase delay is suppressed by calculating the phase delay of the AC voltage with respect to the AC current using the calculation unit 200 shown in FIG.
  • FIG. 23 is a block diagram showing a calculation unit 200 that constitutes a part of the controller 60 of the fuel cell system 100 according to the third embodiment.
  • the calculation unit 200 calculates the phase delay of the AC voltage with respect to the AC current instead of the processing of S201 to S204 in FIG.
  • the process of S205 in FIG. 8 is executed using the phase delay calculated by the calculation unit 200 to calculate the hydrogen concentration.
  • the calculation unit 200 calculates the amplitude Ia of the alternating current based on the alternating current detected when the fuel cell stack 1 is controlled so that the output signal of the fuel cell stack 1 becomes an alternating signal including a frequency of 1 kHz.
  • the alternating current detected by the current sensor 61 is passed through the reverse notch filter similar to S104, and the alternating current value is squared by the multiplying unit 201.
  • the value calculated by the multiplication unit 201 is integrated by the integration unit 202 for a predetermined time, and the division unit 203 divides the integration value by the timer value.
  • the timer value is a value calculated by the timer value calculation unit 205 and is a half of the integration time.
  • the square root of the value calculated by the dividing unit 203 is calculated by the square root calculating unit 204, and the calculated value becomes the amplitude Ia of the alternating current.
  • the multiplication unit 201, the integration unit 202, the division unit 203, and the square root calculation unit 204 of the calculation unit 200 constitute an AC current amplitude calculation unit.
  • the arithmetic unit 200 calculates the amplitude Va of the AC voltage based on the AC voltage detected when the fuel cell stack 1 is controlled so that the output signal of the fuel cell stack 1 becomes an AC signal including a frequency of 1 kHz. To do.
  • the AC voltage detected by the voltage sensor 62 is passed through the reverse notch filter similar to S104, the positive / negative of the AC voltage value is inverted by the gain unit 206, and squared by the multiplication unit 207.
  • the value calculated by the multiplying unit 207 is integrated by the integrating unit 208 for a predetermined time, and the dividing unit 209 divides the integrated value by the timer value.
  • the timer value is a value calculated by the timer value calculation unit 205 and is a half of the integration time.
  • the square root of the value calculated by the dividing unit 209 is calculated by the square root calculating unit 210, and the calculated value becomes the amplitude Va of the AC voltage.
  • the gain unit 206, multiplication unit 207, integration unit 208, division unit 209, and square root calculation unit 210 of the calculation unit 200 constitute an AC voltage amplitude calculation unit.
  • the arithmetic unit 200 calculates the real component Vr of the AC voltage based on the AC current detected by the current sensor 61, the AC voltage detected by the voltage sensor 62, and the calculated amplitude Ia of the AC current. .
  • the alternating current value obtained by passing the detected value of the current sensor 61 through the reverse notch filter similar to that in S 104 and the alternating voltage value output from the gain unit 206 are multiplied by the multiplying unit 211.
  • the integration unit 212 integrates the calculated value for a predetermined time.
  • the integral value calculated by the integration unit 212 is divided by a timer value that is a half of the integration time, and further divided by the amplitude Ia of the alternating current calculated by the square root calculation unit 204. .
  • the value calculated by the dividing unit 213 is the real component Vr of the AC voltage.
  • the multiplication unit 211, the integration unit 212, and the division unit 213 of the calculation unit 200 constitute an AC voltage real part calculation unit.
  • the arithmetic unit 200 calculates the phase delay ⁇ of the AC voltage with respect to the AC current based on the real part component Vr of the AC voltage and the amplitude Va of the AC voltage.
  • the division unit 214 divides the real part component Vr of the AC voltage by the amplitude Va of the AC voltage, and the inverse cosine (arc cosine) of the value calculated by the division unit 214 is calculated by the inverse cosine calculation unit 215.
  • the phase delay ⁇ [°] of the AC voltage with respect to the AC current is calculated.
  • the division unit 214, the inverse cosine calculation unit 215, and the unit conversion gain unit 216 of the calculation unit 200 constitute a phase delay calculation unit.
  • FIG. 25 is a diagram illustrating the phase delay ⁇ of the AC voltage with respect to the AC current calculated by the calculation unit 200.
  • a solid line A indicates a case where the frequencies of the alternating current and the alternating voltage are not deviated from the set frequency.
  • a broken line B indicates a case where the frequency of the alternating current and the alternating voltage is deviated from the set frequency by 10 Hz.
  • An alternate long and short dash line C indicates a case where the frequency of the alternating current and the alternating voltage is shifted from the set frequency by 20 Hz.
  • the phase delay ⁇ of the AC voltage with respect to the AC current calculated by the arithmetic unit 200 is a true value even when the frequency of the AC current and the AC voltage is slightly shifted from the set frequency. For example, it converges to 10 °.
  • the calculation accuracy of the phase lag of the AC voltage with respect to the AC current due to the frequency shift is improved.
  • the deterioration can be suppressed, and the calculation accuracy of the hydrogen concentration in the fuel cell stack 1 can be improved.
  • the hydrogen concentration calculation processing has been described by taking the anode gas non-circulation type fuel cell system 100 as an example, but the hydrogen concentration calculation processing in each embodiment is the anode gas circulation type fuel cell shown in FIG. It can also be applied to the system 100.
  • FIG. 26 is a schematic configuration diagram of an anode gas circulation type fuel cell system 100.
  • the anode gas circulation type fuel cell system 100 has basically the same configuration as the fuel cell system shown in FIG. 1, but an anode off gas containing unreacted hydrogen (anode gas) discharged into the anode gas discharge passage 25. Is different in that a recirculation passage 71 for recirculating the gas to the anode gas supply passage 22 is provided.
  • the anode gas discharge passage 25 is configured to communicate the fuel cell stack 1 with the outside.
  • One end of the reflux passage 71 is connected to a three-way valve 29 provided in the anode gas discharge passage 25, and the other end is connected to the anode gas supply passage 22 between the pressure sensor 24 and the fuel cell stack 1.
  • a circulation pump 72 that pumps the anode off gas to the anode gas supply passage 22 is attached to the reflux passage 71.
  • the circulation pump 72 is configured to be able to adjust the flow rate of the anode off gas to be refluxed.
  • the circulation pump 72 functions as a reflux flow rate adjusting unit that adjusts the flow rate of the anode off-gas to be refluxed, that is, the flow rate of the hydrogen to be refluxed.
  • the anode gas circulation type fuel cell system 100 does not have the buffer tank 26 or the purge valve 28 provided in the fuel cell system shown in FIG.
  • the hydrogen concentration can be calculated using the method described in the first to third embodiments.
  • the anode gas circulation process as shown in FIG. 27 is executed using the calculated hydrogen concentration.
  • FIG. 27 is a flowchart showing an anode gas circulation process executed by the controller 60 of the fuel cell system 100.
  • the anode gas circulation process is executed at a predetermined calculation cycle (for example, a cycle of 100 microseconds) from when the ignition switch is turned on to when it is turned off.
  • the controller 60 determines whether or not an operation condition for operating the circulation pump 72 is satisfied. This is determined based on whether or not the hydrogen concentration in the fuel cell stack 1 has decreased to such an extent that the power generation performance of the fuel cell stack 1 deteriorates.
  • the controller 60 ends the anode gas circulation process.
  • the controller 60 determines that the power generation efficiency may be reduced due to the impure gas. , S602 and S603 are executed.
  • the controller 60 refers to the hydrogen concentration-circulation pump rotation speed characteristics shown in FIG. 28, and determines the circulation pump rotation speed based on the hydrogen concentration calculated during system operation. Thereby, the flow rate of hydrogen refluxed to the anode gas supply passage 22 is set.
  • the hydrogen concentration-circulation pump rotation speed characteristic in FIG. 28 is preset data used for determining the rotation speed of the circulation pump 72 and is stored in the ROM of the controller 60.
  • the hydrogen concentration-circulation pump rotation speed characteristic is set so that the circulation pump rotation speed increases as the hydrogen concentration decreases.
  • the circulation pump rotation speed is set to a predetermined maximum rotation speed.
  • the circulation pump rotation speed is set to a predetermined minimum. Set to rotation speed.
  • the controller 60 performs PID control of the circulation pump 72 so that the rotation speed detected value detected by the rotation speed sensor installed in the circulation pump 72 becomes the circulation pump rotation speed determined in S602, and the anode gas End the circular process.

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Abstract

La présente invention a trait à un système de pile à combustible qui est équipé d'une pile à combustible qui produit de l'énergie à l'aide d'hydrogène, qui est un gaz anodique, lequel système de pile à combustible est doté : d'une unité de calcul de caractéristiques de phase permettant de calculer les caractéristiques de phase de l'impédance interne de la pile à combustible en fonction du signal de sortie provenant de la pile à combustible ; et d'une unité de calcul de la concentration d'hydrogène permettant de calculer la concentration d'hydrogène dans la pile à combustible en fonction des caractéristiques de phase de l'impédance interne.
PCT/JP2012/073980 2011-10-03 2012-09-20 Système de pile à combustible WO2013051397A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016067430A1 (fr) * 2014-10-30 2016-05-06 日産自動車株式会社 Dispositif d'estimation d'état de pile à combustible, procédé d'estimation d'état et système de pile à combustible
DE102020115834A1 (de) 2020-06-16 2021-12-16 Audi Aktiengesellschaft Verfahren zum Ermitteln der Brennstoffkonzentration in einem Anodenkreislauf, Brennstoffzellenvorrichtung und Kraftfahrzeug

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014192649A1 (fr) * 2013-05-30 2014-12-04 日産自動車株式会社 Système de pile à combustible et procédé de commande de celui-ci
CA2938133C (fr) * 2014-01-30 2017-08-29 Nissan Motor Co., Ltd. Systeme de pile a combustible avec regulation de la mouillabilite et de la concentration de gaz d'anode
WO2016059709A1 (fr) * 2014-10-16 2016-04-21 日産自動車株式会社 Système de pile à combustible et procédé de mesure d'impédance
JP6702173B2 (ja) * 2016-12-22 2020-05-27 株式会社Ｓｏｋｅｎ 燃料電池システム

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005129312A (ja) * 2003-10-22 2005-05-19 Denso Corp 燃料電池の燃料供給装置
JP2006164562A (ja) * 2004-12-02 2006-06-22 Denso Corp 燃料電池システム
JP2007165103A (ja) * 2005-12-13 2007-06-28 Toyota Motor Corp 燃料電池システム及びその運転方法並びに移動体
JP2007220538A (ja) * 2006-02-17 2007-08-30 Nissan Motor Co Ltd 燃料電池システム
WO2010128555A1 (fr) * 2009-05-08 2010-11-11 トヨタ自動車株式会社 Dispositif d'estimation de la concentration en hydrogène d'une pile à combustible et système de pile à combustible

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5119565B2 (ja) * 2001-09-12 2013-01-16 株式会社デンソー 燃料電池システム
JP5617749B2 (ja) * 2010-09-10 2014-11-05 株式会社デンソー ガス濃度測定装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005129312A (ja) * 2003-10-22 2005-05-19 Denso Corp 燃料電池の燃料供給装置
JP2006164562A (ja) * 2004-12-02 2006-06-22 Denso Corp 燃料電池システム
JP2007165103A (ja) * 2005-12-13 2007-06-28 Toyota Motor Corp 燃料電池システム及びその運転方法並びに移動体
JP2007220538A (ja) * 2006-02-17 2007-08-30 Nissan Motor Co Ltd 燃料電池システム
WO2010128555A1 (fr) * 2009-05-08 2010-11-11 トヨタ自動車株式会社 Dispositif d'estimation de la concentration en hydrogène d'une pile à combustible et système de pile à combustible

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016067430A1 (fr) * 2014-10-30 2016-05-06 日産自動車株式会社 Dispositif d'estimation d'état de pile à combustible, procédé d'estimation d'état et système de pile à combustible
JPWO2016067430A1 (ja) * 2014-10-30 2018-03-22 日産自動車株式会社 燃料電池の状態推定装置、状態推定方法、及び燃料電池システム
DE102020115834A1 (de) 2020-06-16 2021-12-16 Audi Aktiengesellschaft Verfahren zum Ermitteln der Brennstoffkonzentration in einem Anodenkreislauf, Brennstoffzellenvorrichtung und Kraftfahrzeug

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