JP2015195225A - Start-up method for fuel cell system and fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of a fuel cell from occurring at the time of start-up.SOLUTION: A controller 32 executes: a first process of determining whether or not hydrogen exists in an anode gas passage 44; a second process of making a contactor 30 be in a connection state when it is determined, in the first process, that hydrogen exists in the anode gas passage 44; a third process of driving a circulation pump 22; a fourth process of opening a purge valve 23 while starting supply of an anode gas; a fifth process of closing the purge valve 23; a sixth process of supplying a cathode gas to a cathode; and a seventh process of starting power generation of a fuel cell stack 11 before generating power while keeping its voltage being equal to or lower than predetermined voltage in the case that it is determined, in the first process, that hydrogen exists and the voltage of the fuel cell stack 11 has reached the predetermined voltage, or not starting power generation of the fuel cell stack 11 in the case that it is determined, in the first process, that hydrogen does not exist.

Description

  The present invention relates to a method for starting a fuel cell system and a fuel cell system.

Conventionally, when the fuel cell stack is started, in order to replace (purge) the air existing in the anode with hydrogen, when hydrogen is continuously supplied to the anode, air is not supplied to the cathode, and this replacement (purging) is involved. There is known a starting method in which, after the start-up is completed, the supply of air to the cathode is started and an electric load is connected to the fuel cell stack to generate electric power (see, for example, Patent Document 1).
Conventionally, a method for starting a fuel cell system from a state in which the anode and cathode of a fuel cell stack are filled with air is known (see, for example, Patent Document 2).
In this starting method, when the fuel cell system is started, first, hydrogen is supplied to the anode while adjusting the hydrogen supply flow rate so that the recirculation flow path of the anode does not contain hydrogen and oxygen in a combustible ratio. To form a mixed state of hydrogen and air. Water is then generated by the reaction of hydrogen and oxygen on the anode catalyst until oxygen is no longer present in the anode recirculation flow path. Next, supply of hydrogen and air to the anode and the cathode at a normal flow rate is started, and electric power is generated by connecting an electric load to the fuel cell stack. In this starting method, before the supply of hydrogen to the anode is started, power is generated by connecting an auxiliary load resistor to the fuel cell stack without supplying air to the cathode, and oxygen is generated in the anode recirculation flow path. The cell voltage is kept below a predetermined voltage until it no longer exists.

Japanese Patent No. 4357836 Japanese Patent No. 4137996

By the way, according to the starting method according to the above prior art, since the electric load is connected after the start-up of the fuel cell stack is completed, the cathode has a high potential (for example, the cathode potential is 0.9 V or more). There is a risk that the fuel cell stack deteriorates without being able to avoid becoming.
Also, according to the fuel cell system start-up method according to the above-described prior art, power generation is performed in a state where the hydrogen concentration in the anode is lower than the desired concentration, as in the state where the anode and cathode of the fuel cell stack are filled with air. If this is done, the fuel cell stack may be deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of starting a fuel cell system and a fuel cell system that can prevent the deterioration of the fuel cell during startup.

  In order to solve the above problems and achieve the object, a fuel cell system start-up method according to the first aspect of the present invention includes an anode gas (for example, an anode 11A in the embodiment) supplied to an anode ( For example, a fuel cell (for example, in the embodiment) that generates electricity by cathode gas (for example, air in the embodiment) supplied to a cathode (for example, cathode 11B in the embodiment) and cathode (for example, cathode 11B in the embodiment) Fuel cell stack 11), an anode gas flow path (for example, an anode gas flow path 44 in the embodiment) connected to the anode, and an anode gas supply means for supplying the anode gas to the anode gas flow path (For example, the hydrogen tank 19, the hydrogen cutoff valve 20, and the hydrogen supply valve 21 in the embodiment) and a cathode gas flow path ( For example, the cathode gas channel 41 in the embodiment and cathode gas supply means for supplying the cathode gas to the cathode gas channel (for example, the air pump 13 and the sealing inlet valve 15 and the sealing in the embodiment) An outlet valve 16), voltage detecting means for detecting the voltage of the fuel cell (for example, the voltage sensor 34 in the embodiment), and a contactor capable of switching between connection and disconnection of the fuel cell and an electric load (for example, The contactor 30 in the embodiment, the control means for controlling the anode gas supply means and the cathode gas supply means (for example, the control device 32 in the embodiment), the fuel cell to the electric load And a fuel cell system starting method comprising: adjusting means for adjusting discharge, wherein the fuel cell system seals the cathode of the fuel cell. A valve (for example, the sealing inlet valve 15 and the sealing outlet valve 16 in the embodiment) and an anode gas circulation channel (for example, the circulation channel 46 in the embodiment) capable of circulating the anode gas to the anode. ) And circulation means (for example, the circulation pump 22 in the embodiment), an anode gas discharge channel (for example, the anode gas discharge channel 45 in the embodiment) connected to the discharge side of the anode, A purge valve (for example, a purge valve 23 in the embodiment) that can be switched between opening and closing of the anode gas discharge channel to the outside, and the sealing valve before execution of the power generation mode at startup of the fuel cell A first step of determining whether or not the anode gas is present in the anode gas flow path as the start-up power generation mode, and the anode gas flow path in the first step to the anode gas flow path. When it is determined that node gas is present, the second step of bringing the contactor into a connected state, the third step of driving the circulating means after execution of the second step, and the execution of the third step, A fourth step of starting supply of the anode gas to the anode gas flow path and opening the purge valve; a fifth step of closing the purge valve after execution of the fourth step; and opening the sealing valve. And the sixth step of supplying the cathode gas to the cathode through the cathode gas flow channel, and after the execution of the sixth step, the anode gas is present in the anode gas flow channel in the first step. If the fuel cell voltage detected by the voltage detection means reaches a predetermined voltage, the fuel cell starts to generate power and keeps the voltage below the predetermined voltage. And while performing the power generation of the fuel cell, when the anode gas to the anode gas flow path in said first step determines that there comprises a seventh step is not started power generation of the fuel cell.

  Furthermore, in the fuel cell system activation method according to the second aspect of the present invention, the fuel cell system is mounted on a vehicle (for example, the vehicle 1 in the embodiment), and an activation input that instructs activation of the vehicle. Means (for example, the switch 2 in the embodiment), and the first step includes a step for leaving the fuel cell to stop when the start input means instructs the start of the vehicle, When at least one of voltage, pressure of the anode, and oxygen concentration of the anode or the cathode is in each predetermined state, it is determined that the anode gas is present in the anode gas flow path.

  Furthermore, in the start-up method of the fuel cell system according to the third aspect of the present invention, the fuel cell system includes a cathode gas discharge channel (for example, in the embodiment) connected to the cathode discharge side of the fuel cell. Cathode gas discharge flow path 42) and a bypass flow path (for example, bypass flow path 43 in the embodiment) that can bypass the cathode of the fuel cell and flow the cathode gas to the cathode gas discharge flow path And a bypass valve (for example, the bypass valve 18 in the embodiment), and the sixth step is executed while opening the bypass valve.

  Further, in the fuel cell system start-up method according to the fourth aspect of the present invention, the seventh step is executed such that the voltage of the fuel cell detected by the voltage detection means falls within a predetermined range. The

  Further, the fuel cell system activation method according to the fifth aspect of the present invention includes the execution of the startup power generation mode to the execution of the normal power generation mode when a predetermined time has elapsed from the start of execution of the startup power generation mode. Transition.

  Furthermore, the fuel cell system according to the sixth aspect of the present invention includes an anode gas (for example, hydrogen in the embodiment) and a cathode (for example, implementation) supplied to the anode (for example, the anode 11A in the embodiment). The fuel cell (for example, the fuel cell stack 11 in the embodiment) that generates power by the cathode gas (for example, air in the embodiment) supplied to the cathode 11B) in the form of the anode, and the anode connected to the anode Gas flow path (for example, anode gas flow path 44 in the embodiment) and anode gas supply means for supplying the anode gas to the anode gas flow path (for example, hydrogen tank 19 and hydrogen cutoff valve in the embodiment) 20 and a hydrogen supply valve 21), a cathode gas flow path (for example, a cathode gas flow path 41 in the embodiment) connected to the cathode, and Cathode gas supply means for supplying the cathode gas to the cathode gas flow path (for example, the air pump 13 and the sealing inlet valve 15 and the sealing outlet valve 16 in the embodiment) and a voltage for detecting the voltage of the fuel cell Detection means (for example, voltage sensor 34 in the embodiment), contactor (for example, contactor 30 in the embodiment) capable of switching between connection and disconnection of the fuel cell and the electric load, and supply of the anode gas And a control means for controlling the cathode gas supply means (for example, the control device 32 in the embodiment) and an adjustment means for adjusting the discharge from the fuel cell to the electric load. The fuel cell system includes a sealing valve that seals the cathode of the fuel cell (for example, the sealing inlet valve 15 and the sealing outlet in the embodiment). 16), an anode gas circulation channel (for example, circulation channel 46 in the embodiment) and circulation means (for example, circulation pump 22 in the embodiment) capable of circulating the anode gas to the anode, An anode gas discharge channel (for example, an anode gas discharge channel 45 in the embodiment) connected to the anode discharge side, and a purge valve that can switch between opening and shutting off the anode gas discharge channel to the outside ( For example, with the purge valve 23) in the embodiment, the control means performs a step of closing the sealing valve before the start-up power generation mode of the fuel cell, and as the start-up power generation mode, A first step of determining whether or not the anode gas is present in the anode gas flow path; and when it is determined in the first step that the anode gas is present in the anode gas flow path A second step of bringing the contactor into a connected state; a third step of driving the circulation means after execution of the second step; and after execution of the third step, the anode gas in the anode gas flow path. The cathode gas flow path is executed by starting the supply and opening the purge valve; performing the fourth step after the fourth step; closing the purge valve; opening the sealing valve; A sixth step of supplying the cathode gas to the cathode via the first step, and after the execution of the sixth step, it is determined in the first step that the anode gas is present in the anode gas flow path, and the voltage detecting means When the voltage of the fuel cell detected by the above reaches a predetermined voltage, the power generation of the fuel cell is started, the power generation of the fuel cell is performed while maintaining the voltage below a predetermined voltage, When the anode gas to the anode gas passage in the first step is determined that there is no executes a seventh step is not started power generation of the fuel cell.

  Furthermore, in the fuel cell system according to a seventh aspect of the present invention, the fuel cell system is mounted on a vehicle (for example, the vehicle 1 in the embodiment), and an activation input means (for example, an instruction to activate the vehicle) The control means includes a switch 2) according to the embodiment, and the control means, when the start input means is instructed to start the vehicle in the first step, It is determined that the anode gas is present in the anode gas flow path when at least one of the battery voltage, the anode pressure, and the oxygen concentration of the anode or the cathode is in each predetermined state. .

  Furthermore, in the fuel cell system according to an eighth aspect of the present invention, the fuel cell system includes a cathode gas discharge channel (for example, cathode gas in the embodiment) connected to the cathode discharge side of the fuel cell. A discharge channel 42), a bypass channel (for example, bypass channel 43 in the embodiment) and a bypass valve that can bypass the cathode of the fuel cell and flow the cathode gas to the cathode gas discharge channel (For example, the bypass valve 18 in the embodiment), and the control means executes the sixth step while opening the bypass valve.

  Furthermore, in the fuel cell system according to a ninth aspect of the present invention, the control means executes the seventh step so that the voltage of the fuel cell detected by the voltage detection means falls within a predetermined range. To do.

  Further, in the fuel cell system according to a tenth aspect of the present invention, the control means executes the normal power generation mode instead of the start-time power generation mode when a predetermined time has elapsed from the start of execution of the start-time power generation mode. To do.

According to the start-up method of the fuel cell system according to the first aspect of the present invention, the cathode gas is wasted on the cathode via the cathode gas flow path in the absence of the anode gas on the anode by performing each step in order. Can be prevented.
Furthermore, it is possible to prevent an electric load from being connected to the fuel cell in the absence of anode gas at the anode (that is, the fuel cell generates power), and the fuel cell is caused by a shortage of anode gas during power generation. Can be prevented from deteriorating.
Also, by including the seventh step, an excessive increase in potential without any load (for example, an increase in cathode potential) is prevented, and the fuel cell deteriorates due to the excessive increase in potential. Can be prevented.
In addition, after the bypass valve is opened, the sixth step is performed while the bypass valve is closed and the sealing valve is opened, so that the cathode gas concentration of the cathode can be accurately set to a desired concentration. .
Further, the anode gas concentration of the anode can be accurately set to a desired concentration, and an excessive voltage increase can be appropriately prevented.

According to the starting method of the fuel cell system according to the second aspect of the present invention, at least one of the fuel cell stop leaving time, the fuel cell voltage, the anode pressure, and the anode or cathode oxygen concentration is selected. When one of these is in each predetermined state, it is determined that the anode gas is present in the anode gas flow path.
For example, if the fuel cell stoppage time is within a predetermined time, it is determined that anode gas exists in the anode and the cathode.
For example, if the voltage of the fuel cell is equal to or lower than a predetermined voltage, it is determined that the anode gas is present at the anode.
Further, for example, if the anode pressure is equal to or higher than a predetermined pressure or if the change width of the anode pressure while the fuel cell is stopped is decreasing, it is determined that the anode gas exists in the anode.
Further, for example, when the oxygen concentration of the anode or the cathode is equal to or lower than a predetermined concentration, it is determined that the anode gas exists in the anode.

According to the fuel cell system start-up method of the third aspect of the present invention, when the cathode gas is supplied to the cathode via the cathode gas flow path, the anode gas present in the cathode is discharged into the cathode gas by the cathode gas. Pushed to the road.
In this case, by opening the bypass valve, the anode gas in the cathode gas discharge channel can be diluted with the cathode gas that has flowed through the bypass channel.
Furthermore, since the cathode gas supplied to the cathode gas flow path branches and flows into the cathode and the bypass flow path, the cathode gas introduced into the cathode can be reduced, and the anode gas discharged from the cathode It can prevent that the density | concentration of becomes excessive.

  According to the starting method of the fuel cell system according to the fourth aspect of the present invention, for example, by setting the voltage of the fuel cell to a voltage within a predetermined range by constant voltage control or the like, it is excessively large without requiring complicated control. An increase in potential can be easily prevented.

  According to the fuel cell system startup method of the fifth aspect of the present invention, the gas supply amount and the generated current can be reduced by executing the normal power generation mode after the completion of startup of the fuel cell system. Driving efficiency can be improved.

According to the fuel cell system of the sixth aspect of the present invention, the control means performs the respective steps in order, so that the cathode gas is supplied to the cathode via the cathode gas flow path in the absence of the anode gas in the anode. It is possible to prevent wasteful supply.
Furthermore, it is possible to prevent an electric load from being connected to the fuel cell in the absence of anode gas at the anode (that is, the fuel cell generates power), and the fuel cell is caused by a shortage of anode gas during power generation. Can be prevented from deteriorating.
In addition, the control means executes the seventh step to prevent an excessive increase in potential without any load (for example, an increase in cathode potential), and the fuel cell is caused by the excessive increase in potential. Deterioration can be prevented.
Also, the control means opens the bypass valve, then closes the bypass valve and opens the sealing valve, and executes the sixth step to accurately adjust the cathode gas concentration of the cathode to a desired concentration. can do.
In addition, the control means can accurately set the anode gas concentration of the anode to a desired concentration and appropriately prevent an excessive voltage increase.

According to the fuel cell system of the seventh aspect of the present invention, the control means includes at least one of the fuel cell stop standing time, the fuel cell voltage, the anode pressure, and the anode or cathode oxygen concentration. When any one is in each predetermined state, it is determined that the anode gas is present in the anode gas flow path.
For example, if the fuel cell stoppage time is within a predetermined time, it is determined that anode gas exists in the anode and the cathode.
Further, for example, when the voltage of the fuel cell is equal to or lower than a predetermined voltage, it is determined that the anode gas exists in the anode.
Further, for example, if the anode pressure is equal to or higher than a predetermined pressure or the change width of the anode pressure while the fuel cell is stopped is declining, it is determined that the anode gas exists in the anode.
Further, for example, if the oxygen concentration of the anode or the cathode is not more than a predetermined concentration, it is determined that the anode gas is present at the anode.

According to the fuel cell system of the eighth aspect of the present invention, when the cathode gas is supplied to the cathode through the cathode gas flow path, the anode gas existing in the cathode is transferred to the cathode gas discharge flow path by the cathode gas. Extruded.
In this case, the control means can dilute the anode gas in the cathode gas discharge channel with the cathode gas flowing through the bypass channel by opening the bypass valve.
Furthermore, since the cathode gas supplied to the cathode gas flow path branches and flows into the cathode and the bypass flow path, the cathode gas introduced into the cathode can be reduced, and the anode gas discharged from the cathode It can prevent that the density | concentration of becomes excessive.

  According to the fuel cell system of the ninth aspect of the present invention, the control means is configured so that the voltage of the fuel cell is set within a predetermined range by constant voltage control, for example. Can be easily prevented.

  According to the fuel cell system of the tenth aspect of the present invention, the control means can reduce the gas supply amount and the generated current by executing the normal power generation mode after the start of the fuel cell system is completed, and the fuel cell system The driving efficiency can be improved.

1 is a configuration diagram of a fuel cell system according to an embodiment of the present invention. It is a graph which shows the example of the change of the voltage of a fuel cell stack, the pressure of an anode, and the gas density | concentration of an anode and a cathode in the stop standing state of the fuel cell system which concerns on embodiment of this invention. 5 is a flowchart showing an operation of the fuel cell system according to the embodiment of the present invention, in particular, a control operation by the control device at the time of starting the fuel cell system (that is, a starting method of the fuel cell system). It is a figure which shows the state of each system of an anode, a cathode, and a power supply at the time of starting of the fuel cell system concerning an embodiment of the invention. It is a graph which shows the example of the change of the electric potential of the cathode of the Example and comparative example at the time of starting of the fuel cell system which concerns on embodiment of this invention.

  Hereinafter, a fuel cell system and a fuel cell system activation method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

The fuel cell system 10 according to the present embodiment is mounted as a power source in a vehicle 1 including a motor (M) for driving and a power drive unit (PDU) that controls the motor (M), for example.
The vehicle 1 includes a switch 2 that outputs a signal instructing activation of the vehicle 1 in accordance with an input operation by the driver, such as an ignition switch.

  For example, as shown in FIG. 1, the fuel cell system 10 includes a fuel cell stack 11, an intake 12, an air pump 13, a humidifier 14, a sealed inlet valve 15, a sealed outlet valve 16, and a pressure control valve. 17, bypass valve 18, hydrogen tank 19, hydrogen cutoff valve 20, hydrogen supply valve 21, circulation pump 22, purge valve 23, diluter 24, anode temperature sensor 25 and anode pressure sensor 26. A cathode humidity sensor 27, a cathode temperature sensor 28, a cathode pressure sensor 29, a contactor 30, a voltage regulator 31, and a control device 32.

The fuel cell stack 11 includes, for example, a stacked body (not shown) in which a plurality of fuel battery cells (not shown) are stacked, and a pair of end plates (not shown) that sandwich the stacked body from both sides in the stacking direction. I have.
The fuel cell includes, for example, a membrane electrode assembly (MEA) (not shown) and a pair of separators (not shown) that sandwich the membrane electrode assembly from both sides in the joining direction.
The membrane electrode assembly includes, for example, a fuel electrode (anode) 11A composed of an anode catalyst and a gas diffusion layer, an oxygen electrode (cathode) 11B composed of a cathode catalyst and a gas diffusion layer, and an anode and a cathode from both sides in the thickness direction. And a solid polymer electrolyte membrane 11C made of a cation exchange membrane or the like sandwiched therebetween.

For example, a fuel gas (anode gas) made of hydrogen is supplied from the hydrogen tank 19 to the anode 11A of the fuel cell stack 11, and air, for example, an oxidant gas (cathode gas) containing oxygen is supplied to the cathode 11B. Supplied from the air pump 13.
The hydrogen supplied to the anode 11A is ionized by a catalytic reaction on the anode catalyst, and the hydrogen ions move to the cathode 11B through the appropriately polymerized solid polymer electrolyte membrane 11C. Electrons generated with the movement of hydrogen ions can be taken out to an external circuit (not shown) as a direct current.
The hydrogen ions that have moved from the anode 11A onto the cathode catalyst of the cathode 11B react with oxygen supplied to the cathode and electrons on the cathode catalyst to produce water.

Note that, for example, a reference electrode (not shown) such as DHE (Dynamic Hydrogen Electrode) may be connected to the plurality of fuel cells of the fuel cell stack 11.
For example, the reference electrode can measure the potential (anode potential) of the anode 11A with respect to the reference potential with hydrogen as the reference potential (0 V), and can output a measurement result signal to the control device 32.
For example, the reference electrode may be provided in all of the plurality of fuel cells, or may be provided only in a predetermined fuel cell among the plurality of fuel cells.

The air pump 13 includes, for example, an air compressor that is driven and controlled by the control device 32, takes in air from the outside via the intake 12, compresses the compressed air, and the cathode gas flow path connected to the anode 11 </ b> A 41 is discharged.
For example, the intake 12 is provided with an air flow sensor 33. The air flow sensor 33 detects the flow rate Fb of air taken in from the outside by the air pump 13, and outputs a detection result signal.

The humidifier 14 includes, for example, a water permeable membrane such as a hollow fiber membrane, and uses an exhaust gas (cathode offgas) such as air discharged from the cathode discharge port 11b of the fuel cell stack 11 as a humidifying gas. The air (cathode gas) supplied from the air pump 13 is humidified.
That is, the humidifier 14 makes the exhaust gas by contacting the air supplied from the air pump 13 and the wet exhaust gas discharged from the cathode discharge port 11b of the fuel cell stack 11 through the water permeable membrane, for example. Moisture (especially, water vapor) contained in the water is added to the air (cathode gas) through the membrane holes of the water permeable membrane.

  The sealing inlet valve 15 is provided, for example, in the cathode gas flow path 41 that connects the air pump 13 and the cathode supply port 11a that can supply air to the cathode 11B of the fuel cell stack 11, and is controlled by the control device 32. The cathode gas channel 41 can be shut off.

  The sealing outlet valve 16 is provided, for example, in a cathode gas discharge passage 42 that connects the cathode discharge port 11 b that can discharge air or the like from the cathode 11 B of the fuel cell stack 11 and the diluter 24, and the control device 32. The cathode gas discharge channel 42 can be shut off by controlling the above.

  The pressure control valve 17 is provided, for example, between the humidifier 14 and the diluter 24 in the cathode gas discharge channel 42, and controls the pressure of the cathode off gas in the cathode gas discharge channel 42 under the control of the control device 32.

The bypass valve 18 is, for example, a bypass flow path that connects between the air pump 13 and the humidifier 14 in the cathode gas flow path 41 and between the pressure control valve 17 and the diluter 24 in the cathode gas discharge flow path 42. 43.
The bypass valve 18, for example, can branch the air supplied from the air pump 13 from the cathode gas flow path 41 and supply it to the diluter 24 via the bypass flow path 43, and can be bypassed under the control of the control device 32. The flow path 43 can be blocked.

The hydrogen tank 19 can store compressed hydrogen and discharge hydrogen, for example.
The hydrogen cutoff valve 20 is provided, for example, in an anode gas flow path 44 that connects the hydrogen tank 19 and the anode supply port 11c that can supply hydrogen to the anode 11A of the fuel cell stack 11, and is controlled by the control device 32. The anode gas channel 44 can be shut off.

  The hydrogen supply valve 21 is provided between the hydrogen cutoff valve 20 and the anode supply port 11c in the anode gas flow path 44, for example, for control of the control device 32 or signal pressure due to the pressure of air discharged from the air pump 13. Hydrogen of a corresponding pressure is supplied from the hydrogen tank 19 to the anode gas passage 44. Thereby, the inter-electrode differential pressure between the anode 11A and the cathode 11B of the fuel cell stack 11 is maintained at a predetermined pressure.

The hydrogen supply valve 21 includes, for example, an ejector (not shown) connected to a branch channel 47 branched from the anode gas discharge channel 45.
For example, when the circulation pump 22 is not in operation, the ejector passes at least part of unreacted hydrogen discharged from the anode discharge port 11d through the anode 11A of the fuel cell stack 11 from the hydrogen cutoff valve 20 to the anode. It is mixed with hydrogen supplied to the gas flow path 44 and supplied again to the anode 11 </ b> A of the fuel cell stack 11.

The circulation pump 22 includes, for example, between the hydrogen supply valve 21 and the anode supply port 11c in the anode gas flow path 44, an anode discharge port 11d that can discharge hydrogen and the like from the anode 11A of the fuel cell stack 11, and a diluter 24. Are connected to the circulation flow path 46 connecting the anode gas discharge flow path 45 and the anode gas discharge flow path 45.
The circulation pump 22 passes at least a part of unreacted hydrogen discharged from the anode discharge port 11d through the anode 11A of the fuel cell stack 11 into hydrogen supplied to the anode gas flow path 44 from the hydrogen supply valve 21. After mixing, the fuel cell stack 11 is supplied again to the anode 11A.

  The purge valve 23 is provided, for example, between the anode outlet 11d and the diluter 24 in the anode gas discharge channel 45, and can shut off the anode gas discharge channel 45 under the control of the control device 32. Exhaust gas such as unreacted hydrogen discharged from the outlet 11 d can be supplied to the diluter 24 under the control of the control device 32.

  For example, the diluter 24 dilutes the hydrogen concentration of the exhaust gas supplied from the purge valve 23 with the air supplied from the pressure control valve 17, and the exhaust gas whose diluted hydrogen concentration is reduced to a predetermined concentration or less is externally supplied. (E.g. in the atmosphere).

  The anode temperature sensor 25 and the anode pressure sensor 26 detect, for example, the temperature Ta and the pressure Pa of hydrogen, which is the anode gas supplied to the anode 11A of the fuel cell stack 11, and output a detection result signal.

  The cathode humidity sensor 27, the cathode temperature sensor 28, and the cathode pressure sensor 29 detect, for example, the humidity Hb, temperature Tb, and pressure Pb of air that is cathode gas supplied to the cathode 11B of the fuel cell stack 11, and the detection results. The signal is output.

  The contactor 30 is connected to, for example, a positive electrode and a negative electrode of the fuel cell stack 11, and is connected to the fuel cell stack 11 and an electric load (for example, a power drive unit (PDU) and a motor (M)) under the control of the control device 32. And can be switched off.

  For example, between the fuel cell stack 11 and the contactor 30, the voltage between the positive electrode and the negative electrode of the fuel cell stack 11 (that is, the total voltage that is the sum of the voltages of the plurality of fuel cells) VFC is detected. A sensor 34 is provided, and the voltage sensor 34 outputs a detection result signal.

  The voltage regulator (FCVCU) 31 is disposed, for example, between the positive and negative electrodes of the fuel cell stack 11 via the contactor 30 and the electric load, and is output from the fuel cell stack 11 under the control of the control device 32. The voltage and current can be adjusted.

  The control device 32, for example, after the signal instructing the start of the vehicle 1 from the switch 2 is output, based on the detection result signal output from each sensor 25 to 29, 33, 34, the fuel cell system 10. To control the operation.

In addition, the fuel cell system 10 includes, for example, electric devices to which electric power is supplied from the fuel cell stack 11 such as a driving motor (M) and a power drive unit (PDU) mounted on the vehicle 1, An electric load (for example, a discharge resistor or an electronic load) that can be switched between connection and disconnection to the fuel cell stack 11 and that can change the load current under the control of the control device 32 may be provided.
In this case, the control device 32 can control the discharge to the electric load as the discharge (discharge) at the time of power generation of the fuel cell stack 11.

For example, the control device 32 executes each process as a power generation mode at the time of startup of the fuel cell system 10.
For example, in the first step, the control device 32 determines whether or not hydrogen is present in the anode gas flow path 44.
For example, in the second step, the control device 32 places the contactor 30 in a connected state when it is determined in the first step that hydrogen is present in the anode gas flow path 44.
For example, in the sixth step, the control device 32 supplies air to the cathode 11B via the cathode gas channel 41.
For example, in the seventh step, the control device 32 connects an electric load to the fuel cell stack 11 when the voltage VFC detected by the voltage sensor 34 reaches a predetermined voltage, and outputs the output voltage VFC to the predetermined voltage. While maintaining the following, power generation of the fuel cell stack 11 (that is, discharge to an electric load) is performed.

  For example, in the second step, when the start of the vehicle 1 is instructed by the switch 2, the control device 32, when the start of the vehicle 1 is instructed (soak time), the voltage VFC of the fuel cell stack 11, the anode When at least one of the pressure Pa of 11A and the oxygen concentration of the anode 11A or the cathode 11B is in each predetermined state, the contactor 30 is brought into a connected state.

For example, if the stop standing time (soak time) of the fuel cell system 10 is within a predetermined time, the control device 32 determines that hydrogen is present in the anode 11A and the cathode 11B.
For example, if the voltage VFC of the fuel cell stack 11 is equal to or lower than a predetermined voltage, the control device 32 determines that hydrogen exists in the anode 11A. On the other hand, when the voltage VFC of the fuel cell stack 11 is higher than a predetermined voltage, the voltage VFC rises due to the presence of oxygen at the cathode 11B and the supply of hydrogen to the anode 11A. Judge that there is a possibility.
Further, for example, if the pressure Pa of the anode 11A is equal to or higher than the predetermined pressure or if the change width of the pressure Pa of the anode 11A while the fuel cell system 10 is stopped is decreasing, the control device 32 indicates that hydrogen exists in the anode 11A. judge.
For example, the control device 32 determines that hydrogen is present in the anode 11A if the oxygen concentration of the anode 11A or the cathode 11B is equal to or lower than a predetermined concentration.

For example, as shown in FIGS. 2A to 2C, after the fuel cell system 10 is stopped last time, a predetermined power generation at the time of stop is executed and the oxygen concentration of the cathode 11B is reduced. When the sealing outlet valve 16 is shut off and left in a stopped state, the oxygen concentration of the cathode 11B becomes substantially zero.
On the other hand, as the soak time increases, the hydrogen concentration and pressure of the anode 11A change with a tendency to decrease due to the outflow of hydrogen from the anode 11A and the consumption of hydrogen accompanying the inflow of air to the anode 11A.
When the soak time is increased, for example, after time ta, when the hydrogen concentration of the anode 11A decreases to a predetermined concentration or less, the air flowing into the anode 11A remains, so that the voltage VFC of the fuel cell stack 11 is zero. The pressure of the anode 11A changes to an increasing tendency.
Therefore, it is determined that hydrogen exists in the anode 11A when the voltage VFC of the fuel cell stack 11 is equal to or lower than the predetermined voltage and when the change width of the pressure Pa of the anode 11A tends to decrease.

For example, the control device 32 performs the sixth step while opening the bypass valve 18.
For example, after the bypass valve 18 is opened, the control device 32 closes the bypass valve 18 and opens the sealing inlet valve 15 and the sealing outlet valve 16 to execute the sixth step.
The control device 32 executes the seventh step so that the voltage VFC of the fuel cell stack 11 detected by the voltage sensor 34 becomes a voltage within a predetermined range by, for example, constant voltage control.

For example, the control device 32 executes the normal power generation mode instead of the power generation mode at startup when a predetermined time has elapsed since the start of execution of the power generation mode at startup.
The normal power generation mode is an operation mode including, for example, an idle operation state of the fuel cell system 10, and is more air-stoky (that is, a cathode required to output a desired power generation current) than the power generation mode at startup. This is an operation mode in which the ratio of the supply amount to the theoretical gas consumption amount is smaller and the generated current is smaller.

Moreover, the control apparatus 32 performs each process as the power generation mode at the time of starting of the fuel cell system 10, for example.
For example, in the second step, the control device 32 switches the contactor 30 from the open state to the connected state.
For example, the control device 32 drives the circulation pump 22 in the third step.
For example, in the fourth step, the control device 32 starts supplying hydrogen to the anode gas flow path 44 and opens the purge valve 23.

For example, in the fifth step, the control device 32 closes the purge valve 23 after performing a predetermined purge.
For example, in the sixth step, the control device 32 supplies air to the cathode 11B via the cathode gas channel 41.
For example, in the seventh step, the control device 32 connects an electric load to the fuel cell stack 11 when the voltage VFC detected by the voltage sensor 34 reaches a predetermined voltage, and outputs the output voltage VFC to the predetermined voltage. While maintaining the following, power generation of the fuel cell stack 11 (that is, discharge to an electric load) is performed.

  The fuel cell system 10 according to the present embodiment has the above-described configuration. Next, the fuel cell system after a signal instructing the operation of the fuel cell system 10, particularly the start of the vehicle 1, is output from the switch 2. The control operation by the control device 32 at the time of starting 10 (that is, the starting method of the fuel cell system 10) will be described.

First, for example, in step S01 shown in FIG. 3, whether or not the stop time (soak time) of the fuel cell system 10 with the sealing inlet valve 15 and the sealing outlet valve 16 shut off is within a predetermined time, Alternatively, whether or not the voltage VFC of the fuel cell stack 11 is equal to or lower than a predetermined voltage, or whether or not the pressure of the anode 11A (for example, the pressure of hydrogen at the inlet side of the anode 11A) Pa is equal to or higher than the predetermined pressure. judge.
If at least one of these determination results is “YES”, it is determined that hydrogen exists in the anode 11A, and the process proceeds to step S02. In step S02, “1” indicating that the power generation of the fuel cell stack 11 (that is, the discharge to the electric load) is performed is set in the flag value of the startup discharge execution flag F_STDCHGOK.
On the other hand, when all of these determination results are “NO”, it is determined that hydrogen does not exist in the anode 11A, and the process proceeds to step S03. In step S03, “0” indicating prohibition of power generation (that is, discharge to the electric load) of the fuel cell stack 11 is set in the flag value of the startup discharge execution flag F_STDCHGOK.

Next, in step S04, the contactor 30 is switched from the open state to the connected state. And the bypass valve 18, the hydrogen cutoff valve 20, and the hydrogen supply valve 21 are opened.
Then, the circulating pump 22 is driven, and a predetermined starting command value (predetermined circulating pump command value) is set as a command value for the rotational speed of the circulating pump 22.

  Next, in step S05, the air pump 13 is driven, and as a command value for the number of revolutions of the air pump 13, for example, a predetermined startup command value corresponding to a predetermined dilution air amount of air supplied to the diluter 24 ( Predetermined air pump command value) is set.

  Next, in step S06, supply of hydrogen to the anode gas flow path 44 is started, and control is performed so that the pressure of the anode 11A (for example, the pressure of hydrogen at the inlet side of the anode 11A) Pa becomes a predetermined target pressure. To do.

Next, in step S07, it is determined whether or not the pressure of the anode 11A (for example, the pressure of hydrogen on the inlet side of the anode 11A) Pa is higher than a predetermined purge permission pressure.
If the determination result is “NO”, the determination process of step S07 is repeated.
On the other hand, if the determination is “YES”, the flow proceeds to step S08.

In step S08, the purge valve 23 is opened.
In step S09, it is determined whether the hydrogen purge amount (that is, the hydrogen discharge amount from the purge valve 23) is larger than a predetermined OCV purge amount.
If the determination result is “NO”, the determination process of step S07 is repeated.
On the other hand, if the determination result is “YES”, the purge valve 23 is closed and the process proceeds to step S10.

Next, in step S10, it is determined whether or not a predetermined time has elapsed since the purge valve 23 was closed.
If the determination result is “NO”, the determination process of step S10 is repeated.
On the other hand, if this determination is “YES”, the flow proceeds to step S11.
Next, in step S11, the sealed inlet valve 15 and the sealed outlet valve 16 in the shut-off state are switched to the open state.

Next, in step S12, it is determined whether or not the startup discharge execution flag F_STDCHGOK is “1”.
If this determination is “NO”, the flow proceeds to step S 15 described later.
On the other hand, if the determination is “YES”, the flow proceeds to step S13.

Next, in step S13, it is determined whether or not the voltage VFC of the fuel cell stack 11 is higher than a predetermined power generation permission voltage.
If this determination is “NO”, the flow proceeds to step S 15 described later.
On the other hand, if the determination is “YES”, the flow proceeds to step S14.
In step S14, the power generation of the fuel cell stack 11 (that is, discharge to the electric load) is started.

Next, in step S15, it is determined whether or not a predetermined time has elapsed since the sealed inlet valve 15 and the sealed outlet valve 16 in the shut-off state are switched to the open state.
If the determination result is “NO”, the determination process of step S15 is repeated.
On the other hand, if this determination is “YES”, the flow proceeds to step S16.
In step S16, the bypass valve 18 is closed.
Next, in step S17, as a command value for the rotation speed of the air pump 13, for example, a predetermined activation corresponding to a predetermined normal operation air amount discharged to the cathode gas passage 41 in an idle operation state of the air pump 13 or the like. A post command value (for example, a predetermined idle command value) is set, and the process proceeds to the end.

  For example, in the state where the fuel cell system 10 is stopped (soaked) when the vehicle 1 is stopped as in the period from time t0 to time t1 shown in FIG. 4, the sealing inlet valve 15, the sealing outlet valve 16, and the bypass valve 18, the hydrogen cutoff valve 20, the hydrogen supply valve 21, and the purge valve 23 are in a cutoff (CLOSE) state. Further, the air pump 13 and the circulation pump 22 are in a stopped (OFF) state, the contactor 30 is in an open (OFF) state, and the pressure of the anode 11A, the voltage VFC of the fuel cell stack 11 and the generated current are zero.

For example, at time t1 when a signal instructing activation of the vehicle 1 is output from the switch 2, replacement of the anode 11A with hydrogen in a no-load state (that is, a non-power generation state) in which the fuel cell stack 11 is disconnected from an electric load ( A so-called OCV purge is started.
In this anode replacement, the bypass valve 18, the hydrogen cutoff valve 20, and the hydrogen supply valve 21 are switched from the cutoff state to the open (OPEN) state. Then, the contactor 30 is switched from the open state to the connected (ON) state. Then, the circulation pump 22 starts to be driven.
Further, the air pump 13 starts to be driven at time t1, that is, at time t2 after a predetermined time from the connection (ON) timing of the contactor 30.

Thus, for example, hydrogen is added to the anode 11A where it is determined that hydrogen exists according to the soak time, and the anode pressure Pa gradually increases from zero after time t1.
For example, when the pressure Pa of the anode 11A reaches a predetermined purge permission pressure P1 at time t3, the purge valve 23 is switched from the shut-off state to the open state.
For example, at time t4 when the hydrogen purge amount (that is, the hydrogen discharge amount from the purge valve 23) is larger than the predetermined OCV purge amount, the purge valve 23 is switched from the open state to the shut-off state.

  For example, at a time t5 when a predetermined time has elapsed since the purge valve 23 is turned off, the sealing inlet valve 15 and the sealing outlet valve 16 are switched from the cutoff state to the open state. Thereby, the anode replacement is completed, and the replacement of the cathode 11B with air is started. By the start of the cathode replacement, air is supplied to the cathode 11B, and the voltage VFC of the fuel cell stack 11 gradually increases from zero after time t5.

  In addition, after a predetermined time has elapsed after the purge valve 23 is shut off, the anode replacement is terminated and the cathode replacement is performed, whereby the hydrogen discharged from the purge valve 23 in the anode replacement is diluted with air, The concentration of hydrogen discharged from the purge valve 23 by cathode replacement is set so as not to exceed a predetermined specified value.

For example, the bypass valve 18 is closed at a time t6 when an appropriate time has elapsed.
Further, for example, at time t7 when the voltage VFC of the fuel cell stack 11 reaches a predetermined power generation permission voltage V1, power generation of the fuel cell stack 11 (that is, discharge to an electric load) is started by constant voltage control, and the fuel cell stack 11 generated current changes from zero to a predetermined current I1.

  Then, for example, at time t8 when a predetermined time has elapsed since the sealed inlet valve 15 and the sealed outlet valve 16 are switched to the open state, the air pump 13 is stopped, the cathode replacement is completed, and the fuel cell system 10 Is complete.

When the fuel cell system 10 is started by executing anode replacement and cathode replacement as shown in FIG. 4 described above, the fuel cell stack 11 is taken at time ts, for example, as in the embodiment shown in FIG. By executing this power generation (that is, discharging to an electric load), the potentials of the cathodes 11B of the plurality of fuel cells of the fuel cell stack 11 can be suppressed to about the predetermined potential Va.
On the other hand, when the fuel cell system 10 is started without executing the power generation of the fuel cell stack 11 (that is, discharging to the electric load), for example, as in the comparative example shown in FIG. There is a possibility that the potential of the cathode 11B of the plurality of fuel cells of the battery stack 11 rises to about the potential Vb higher than the predetermined potential Va, and the cathode catalyst is deteriorated.

As described above, according to the fuel cell system 10 and the start-up method of the fuel cell system 10 according to the present embodiment, when it is determined that hydrogen is present in the anode gas passage 44, the cathode gas passage 41 is interposed. Since air is supplied to the cathode 11B, it is possible to prevent wasteful supply of air to the cathode 11B via the cathode gas channel 41 in a state where hydrogen does not exist in the anode 11A.
Further, it is possible to prevent an electrical load from being connected to the fuel cell stack 11 in the absence of hydrogen at the anode 11A, and the fuel cell stack 11 is deteriorated due to a shortage of anode gas during power generation of the fuel cell stack 11. Can be prevented.
Further, by generating the fuel cell stack 11 while maintaining the voltage VFC below a predetermined voltage (that is, discharging to an electric load), an excessive increase in potential without load (for example, increase in the potential of the cathode 11B) ), And deterioration of the fuel cell stack 11 due to an excessive increase in potential can be prevented.

Further, the bypass valve 18 is opened when the sealed inlet valve 15 and the sealed outlet valve 16 in the shut-off state are switched to the open state and the supply of air to the cathode 11B via the cathode gas flow path 41 is started. Thus, the hydrogen in the cathode gas discharge passage 42 pushed out by air from the cathode 11B can be diluted with the air flowing through the bypass passage 43.
Furthermore, since the air supplied to the cathode gas channel 41 branches and flows into the cathode 11B and the bypass channel 43, the air introduced into the cathode 11B can be reduced and discharged from the cathode 11B. It is possible to prevent the hydrogen concentration from becoming excessive.

  Further, when the fuel cell stack 11 performs power generation (that is, discharge to an electric load), after opening the bypass valve, the bypass valve 18 is closed and the sealed inlet valve 15 and the sealed outlet valve 16 are opened. Thus, the oxygen concentration of the cathode 11B can be accurately set to a desired concentration.

  Further, when power generation of the fuel cell stack 11 (that is, discharge to an electric load) is performed, complicated control is required by setting the voltage VFC of the fuel cell stack 11 within a predetermined range by, for example, constant voltage control or the like. Therefore, an excessive increase in potential can be easily prevented.

  In addition, after the completion of startup of the fuel cell system 10, it is possible to reduce the amount of air supplied to the cathode 11 </ b> B and the generated current by executing the normal power generation mode including the idling operation state, thereby improving the operation efficiency of the fuel cell system 10 Can be made.

Further, by performing the anode replacement, the hydrogen concentration of the anode 11A can be accurately set to a desired concentration.
Further, by maintaining the sealed state of the cathode 11B by the sealed inlet valve 15 and the sealed outlet valve 16 during the anode replacement, the oxygen in the system of the cathode 11B has a lower concentration than the atmosphere. The generation of the in-plane current can be suppressed (that is, the inter-electrode movement of hydrogen ions can be suppressed).

In the above-described embodiment, for example, the contactor 30 and the circulation pump 22 may be omitted.
Further, when the concentration of hydrogen existing in the anode 11A in advance is equal to or higher than a predetermined concentration, anode replacement, that is, supply of hydrogen to the anode 11A and opening of the purge valve 23 over a predetermined period may be omitted.

In the embodiment described above, for example, as shown in FIG. 4, after the air is supplied to the cathode 11B, after the voltage VFC of the fuel cell stack 11 reaches a predetermined power generation permission voltage V1, the fuel cell stack 11 However, the present invention is not limited to this. For example, the power generation of the fuel cell stack 11 may be started simultaneously with the start of the supply of air to the cathode 11B.
Even in this case, since it is known in advance that hydrogen is present in the anode 11A, the supply to the anode stoichiometric (that is, supply of the theoretical consumption of anode gas required for outputting a desired generated current) The amount ratio) can be prevented from being insufficient, and the deterioration of the fuel cell stack 11 can be prevented.

  Note that, in the above-described embodiment, the gas environment inside the fuel cell stack 11 changes depending on the external environment by including the sealing inlet valve 15 and the sealing outlet valve 16 and putting the cathode 11B in a sealed state. Can be prevented satisfactorily.

  In the embodiment described above, the sealing inlet valve 15 and the sealing outlet valve 16 may be omitted.

  The present embodiment described above shows an example in carrying out the present invention, and it goes without saying that the present invention is not construed as being limited to the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Switch 10 Fuel cell system 11 Fuel cell stack (fuel cell)
11A Anode 11B Cathode 13 Air pump (cathode gas supply means)
15 Sealing inlet valve (cathode gas supply means, sealing valve)
16 Sealing outlet valve (cathode gas supply means, sealing valve)
18 Bypass valve 19 Hydrogen tank (Anode gas supply means)
20 Hydrogen shut-off valve (Anode gas supply means)
21 Hydrogen supply valve (anode gas supply means)
22 Circulation pump (circulation means)
23 Purge valve 30 Contactor 32 Control device (control means)
34 Voltage sensor (voltage detection means)
41 Cathode gas passage 42 Cathode gas discharge passage 43 Bypass passage 44 Anode gas passage 45 Anode gas discharge passage 46 Circulation passage (Anode gas circulation passage)

In order to solve the above problems and achieve the object, a fuel cell system start-up method according to the first aspect of the present invention includes an anode gas (for example, an anode 11A in the embodiment) supplied to an anode ( For example, a fuel cell (for example, in the embodiment) that generates electricity by cathode gas (for example, air in the embodiment) supplied to a cathode (for example, cathode 11B in the embodiment) and cathode (for example, cathode 11B in the embodiment) Fuel cell stack 11), an anode gas flow path (for example, an anode gas flow path 44 in the embodiment) connected to the anode, and an anode gas supply means for supplying the anode gas to the anode gas flow path (For example, the hydrogen tank 19, the hydrogen cutoff valve 20, and the hydrogen supply valve 21 in the embodiment) and a cathode gas flow path ( For example, the cathode gas channel 41 in the embodiment and cathode gas supply means for supplying the cathode gas to the cathode gas channel (for example, the air pump 13 and the sealing inlet valve 15 and the sealing in the embodiment) Outlet valve 16), voltage detection means for detecting the voltage of the fuel cell (for example, voltage sensor 34 in the embodiment), control means for controlling the anode gas supply means and the cathode gas supply means (for example, A control device 32) in the embodiment, and an electric load (for example, a motor, a power drive unit, and a circulation pump 22 in the embodiment) connected to the fuel cell. , the fuel cell system comprises determining means for determining whether the anode gas exists in the anode gas passage, the startup onset As the mode, wherein when said anode gas to the anode gas flow path is determined in the first step of determining whether there, and the anode gas to the anode gas flow path in said first step exists Driving the cathode gas supply means to supply the cathode gas to the cathode via the cathode gas flow path; determining that the anode gas is present in the anode gas flow path in the first step; and When the voltage of the fuel cell detected by the voltage detecting means reaches a predetermined voltage, the electric load is connected and the fuel cell is generated while maintaining the voltage at a predetermined voltage or less, and the first including the a higher power determination Engineering I do not want to start power generation of the fuel cell when the anode gas to the anode gas channel is determined not to exist in step Mu

Further, in the fuel cell system start-up method according to the second aspect of the present invention, the fuel cell system is capable of circulating the anode gas through an anode gas circulation channel (for example, the circulation channel 46 in the embodiment). A circulation means for circulating at least a part of the unreacted anode gas discharged through the anode to the anode (for example, the circulation pump 22 in the embodiment), the fuel cell, and the electricity A contactor (for example, contactor 30 in the embodiment) that can be switched between connection and disconnection with a load, and the fuel cell and the electric load are arranged, and the voltage and current output from the fuel cell are Adjusting means (for example, voltage regulator 31 in the embodiment) for adjusting, the electrical load includes the circulating means, the contactor from the open state to the connected state A switch, said by adjusting means to enable driving said circulating means by adjusting the voltage and current output from the fuel cell, comprising the step of circulating the anode gas to the anode.

Furthermore, in the start-up method of the fuel cell system according to the third aspect of the present invention, the fuel cell system includes an anode gas discharge channel (for example, anode gas discharge in the embodiment) connected to the discharge side of the anode. A flow path 45) and a purge valve (for example, the purge valve 23 in the embodiment) that can be switched between open and shut off of the anode gas discharge flow path before the power generation determination step. In addition, when the supply of the anode gas to the anode gas flow path is started and the purge valve is opened, and after the purge valve is opened, when the discharge amount of the anode is larger than a predetermined amount, Closing the purge valve.

Furthermore, in the start-up method of the fuel cell system according to the fourth aspect of the present invention, the fuel cell system uses a diluter that dilutes the concentration of the anode gas supplied from the purge valve (for example, in the embodiment). A diluter 24) and a bypass flow path (for example, a flow path for bypassing the cathode of the fuel cell to the cathode gas discharge flow path (for example, the cathode gas discharge flow path 42 in the embodiment)) A bypass valve (for example, the bypass valve 18 in the embodiment) provided in the bypass flow path 43) in the embodiment, and the step of opening the bypass valve before the step of opening the purge valve including.

Further, in the fuel cell system start-up method according to the fifth aspect of the present invention, the determination means determines whether or not the fuel cell system standstill time is within a predetermined time; and A second determination for determining whether or not the fuel cell voltage is equal to or lower than a predetermined voltage; and whether or not the pressure of the anode is equal to or higher than a predetermined pressure or the pressure of the anode while the fuel cell system is stopped And a third determination for determining whether or not the change width is decreasing. If at least one of the determination results from the first determination to the third determination is “YES”, the anode is connected to the anode. It is determined that anode gas is present.

Furthermore, the fuel cell system according to the sixth aspect of the present invention includes an anode gas (for example, hydrogen in the embodiment) and a cathode (for example, implementation) supplied to the anode (for example, the anode 11A in the embodiment). The fuel cell (for example, the fuel cell stack 11 in the embodiment) that generates power by the cathode gas (for example, air in the embodiment) supplied to the cathode 11B) in the form of the anode, and the anode connected to the anode Gas flow path (for example, anode gas flow path 44 in the embodiment) and anode gas supply means for supplying the anode gas to the anode gas flow path (for example, hydrogen tank 19 and hydrogen cutoff valve in the embodiment) 20 and a hydrogen supply valve 21), a cathode gas flow path (for example, a cathode gas flow path 41 in the embodiment) connected to the cathode, and Cathode gas supply means for supplying the cathode gas to the cathode gas flow path (for example, the air pump 13 and the sealing inlet valve 15 and the sealing outlet valve 16 in the embodiment) and a voltage for detecting the voltage of the fuel cell Detection means (for example, voltage sensor 34 in the embodiment), control means (for example, control device 32 in the embodiment) for controlling the anode gas supply means and the cathode gas supply means, the fuel cell, A fuel cell system including a connected electrical load (for example, a motor, a power drive unit, and a circulation pump 22 in the embodiment) , wherein the anode gas is present in the anode gas flow path. comprising a determining means for determining whether or not to said control means, as the previous SL startup generation mode, prior to the anode gas channel A first step of determining whether the anode gas is present, drives the cathode gas supply means when the anode gas to the anode gas flow path in said first step is determined to exist, the cathode Supplying the cathode gas to the cathode via a gas flow path; and determining the presence of the anode gas in the anode gas flow path in the first step, and detecting the fuel cell detected by the voltage detection means When the voltage reaches a predetermined voltage, the electric load is connected and the fuel cell is generated while maintaining the voltage at a predetermined voltage or lower. In the first step, the anode gas flow path is connected to the anode when it is determined that the gas is not present to perform the, and as power determination Engineering do not want to start power generation of the fuel cell.

Furthermore, in the fuel cell system according to a seventh aspect of the present invention, the fuel cell system is provided in an anode gas circulation channel (for example, the circulation channel 46 in the embodiment) capable of circulating the anode gas. Circulating means for circulating at least a part of the unreacted anode gas discharged through the anode to the anode (for example, the circulation pump 22 in the embodiment), the fuel cell, and an electric load Adjustment which adjusts the voltage and current which are arranged between the contactor (for example, contactor 30 in an embodiment) which can be switched between connection and disconnection, and the fuel cell and the electric load and which are output from the fuel cell Means (for example, voltage regulator 31 in the embodiment), the electric load includes the circulation means, and the control means connects the contactor from an open state. Switching to a state, the by adjustment means to enable driving said circulating means by adjusting the voltage and current output from the fuel cell, performing the step of circulating the anode gas to the anode.

Furthermore, in the fuel cell system according to an eighth aspect of the present invention, the fuel cell system includes an anode gas discharge channel (for example, the anode gas discharge channel 45 in the embodiment) connected to the anode discharge side. ) And a purge valve (for example, purge valve 23 in the embodiment) that can be switched between open and shut off with respect to the outside of the anode gas discharge channel, and the control means performs the power generation determination step Before starting the supply of the anode gas to the anode gas flow path and opening the purge valve; and after opening the purge valve, if the discharge amount of the anode is larger than a predetermined amount And closing the purge valve.

Furthermore, in the fuel cell system according to the ninth aspect of the present invention, the fuel cell system dilutes the concentration of the anode gas supplied from the purge valve (for example, the diluter 24 in the embodiment). ) And a bypass channel (for example, an embodiment) that can bypass the cathode of the fuel cell and flow the cathode gas to a cathode gas discharge channel (for example, the cathode gas discharge channel 42 in the embodiment). A bypass valve provided in the bypass flow path 43) (for example, the bypass valve 18 in the embodiment), and the control means opens the bypass valve before the step of opening the purge valve. The process to perform is performed.

Furthermore, in the fuel cell system according to a tenth aspect of the present invention, the determination means includes a first determination for determining whether or not the stoppage time of the fuel cell system is within a predetermined time; A second determination for determining whether or not the voltage is equal to or lower than a predetermined voltage; whether or not the pressure of the anode is equal to or higher than a predetermined pressure; or a change width of the pressure of the anode while the fuel cell system is stopped A third determination for determining whether or not the trend is decreasing, and the control means determines that the anode is in the case where the determination result of at least one of the first determination to the third determination is “YES”. It is determined that the anode gas is present.

According to method of starting a fuel cell system according to the first aspect of the present invention, to prevent the cathode gas is wastefully supplied to the cathode through the cathode gas channel in the absence of the anode gas in the A node be able to.
Furthermore, it is possible to prevent an electric load from being connected to the fuel cell in the absence of anode gas at the anode (that is, the fuel cell generates power), and the fuel cell is caused by a shortage of anode gas during power generation. Can be prevented from deteriorating.
In addition, by including a power generation determination step, an excessive increase in potential without any load (for example, an increase in cathode potential) is prevented, and the fuel cell is deteriorated due to an excessive increase in potential. Can be prevented .
Also, while the desired concentration accurately the concentration of the anode gas in the anode, it is possible to suitably prevent the excessive voltage increase.

According to the start-up method of the fuel cell system according to the second aspect of the present invention, it is possible to prevent an electrical load from being connected to the fuel cell in a state where no anode gas is present at the anode (that is, the fuel cell generates power). It is possible to prevent the fuel cell from deteriorating due to the shortage of anode gas during power generation.

According to the starting method of the fuel cell system according to the third aspect of the present invention, it is possible to prevent the fuel cell from deteriorating due to the shortage of anode gas during power generation.

According to the start-up method of the fuel cell system according to the fourth aspect of the present invention, the anode gas in the cathode gas discharge channel can be diluted with the cathode gas flowing through the bypass channel by opening the bypass valve. it can. Further, the anode gas concentration of the anode can be accurately set to a desired concentration, and an excessive voltage increase can be appropriately prevented.

According to the start-up method of the fuel cell system according to the fifth aspect of the present invention, it is possible to prevent an electrical load from being connected to the fuel cell in the absence of the anode gas at the anode (that is, the fuel cell generates power). It is possible to prevent the fuel cell from deteriorating due to the shortage of anode gas during power generation.

According to a sixth fuel cell system according to the invention of the present invention, it is possible to prevent the cathode gas is wastefully supplied to the cathode through the cathode gas channel in the absence of the anode gas in the A node .
Furthermore, it is possible to prevent an electric load from being connected to the fuel cell in the absence of anode gas at the anode (that is, the fuel cell generates power), and the fuel cell is caused by a shortage of anode gas during power generation. Can be prevented from deteriorating.
In addition, by including a power generation determination step, an excessive increase in potential without any load (for example, an increase in cathode potential) is prevented, and the fuel cell is deteriorated due to an excessive increase in potential. Can be prevented .
Also, while the desired concentration accurately the concentration of the anode gas in the anode, it is possible to suitably prevent the excessive voltage increase.

According to the fuel cell system of the seventh aspect of the present invention, it is possible to prevent an electrical load from being connected to the fuel cell in the absence of the anode gas at the anode (that is, the fuel cell can generate power). The fuel cell can be prevented from deteriorating due to the shortage of anode gas during power generation.

According to the fuel cell system of the eighth aspect of the present invention, it is possible to prevent the fuel cell from deteriorating due to the shortage of anode gas during power generation.

According to the fuel cell system of the ninth aspect of the present invention, the anode gas in the cathode gas discharge channel can be diluted with the cathode gas flowing through the bypass channel by opening the bypass valve. Further, the anode gas concentration of the anode can be accurately set to a desired concentration, and an excessive voltage increase can be appropriately prevented.

According to the fuel cell system of the tenth aspect of the present invention, it is possible to prevent an electrical load from being connected to the fuel cell in the absence of anode gas at the anode (that is, the fuel cell can generate power). The fuel cell can be prevented from deteriorating due to the shortage of anode gas during power generation.

Claims (10)

A fuel cell that generates electricity using the anode gas supplied to the anode and the cathode gas supplied to the cathode;
An anode gas flow path connected to the anode, and an anode gas supply means for supplying the anode gas to the anode gas flow path;
A cathode gas flow path connected to the cathode, and a cathode gas supply means for supplying the cathode gas to the cathode gas flow path;
Voltage detecting means for detecting the voltage of the fuel cell;
A contactor capable of switching between connection and disconnection between the fuel cell and an electric load;
Control means for controlling the anode gas supply means and the cathode gas supply means;
Adjusting means for adjusting discharge from the fuel cell to the electrical load;
A method for starting a fuel cell system comprising:
The fuel cell system includes:
A sealing valve for sealing the cathode of the fuel cell;
An anode gas circulation channel and circulation means capable of circulating the anode gas to the anode;
An anode gas discharge passage connected to the discharge side of the anode, and a purge valve capable of switching between opening and closing of the anode gas discharge passage to the outside;
With
Closing the sealing valve before execution of the power generation mode at startup of the fuel cell,
As the start-up power generation mode,
A first step of determining whether or not the anode gas is present in the anode gas flow path;
A second step of bringing the contactor into a connected state when it is determined in the first step that the anode gas is present in the anode gas flow path;
A third step of driving the circulating means after execution of the second step;
A fourth step of starting supply of the anode gas to the anode gas flow path and opening the purge valve after the execution of the third step;
A fifth step of closing the purge valve after execution of the fourth step;
A sixth step that is performed by opening the sealing valve and supplying the cathode gas to the cathode via the cathode gas flow path;
After execution of the sixth step, when it is determined in the first step that the anode gas is present in the anode gas flow path, and the voltage of the fuel cell detected by the voltage detection means reaches a predetermined voltage Starts power generation of the fuel cell, performs power generation of the fuel cell while maintaining the voltage below a predetermined voltage, and determines that the anode gas does not exist in the anode gas flow path in the first step. Is a seventh step not starting power generation of the fuel cell;
A method for starting a fuel cell system, comprising: The fuel cell system is mounted on a vehicle,
A start input means for instructing start of the vehicle;
The first step includes
When the start of the vehicle is instructed by the start input means, the fuel cell stop standing time, the voltage of the fuel cell, the pressure of the anode, and the oxygen concentration of the anode or the cathode 2. The method of starting a fuel cell system according to claim 1, wherein the anode gas is determined to be present in the anode gas flow path when at least one of them is in each predetermined state. The fuel cell system includes:
A cathode gas discharge passage connected to the cathode discharge side of the fuel cell;
A bypass flow path and a bypass valve capable of bypassing the cathode of the fuel cell and flowing the cathode gas to the cathode gas discharge flow path,
The method of starting a fuel cell system according to claim 1 or 2, wherein the sixth step is executed while the bypass valve is opened. 4. The method according to claim 1, wherein the seventh step is executed such that the voltage of the fuel cell detected by the voltage detection unit falls within a predetermined range. 5. A start-up method of the fuel cell system described. The transition from the execution of the startup power generation mode to the execution of the normal power generation mode when a predetermined time elapses from the start of execution of the startup power generation mode. The start method of the fuel cell system as described in 2. A fuel cell that generates electricity using the anode gas supplied to the anode and the cathode gas supplied to the cathode;
An anode gas flow path connected to the anode, and an anode gas supply means for supplying the anode gas to the anode gas flow path;
A cathode gas flow path connected to the cathode, and a cathode gas supply means for supplying the cathode gas to the cathode gas flow path;
Voltage detecting means for detecting the voltage of the fuel cell;
A contactor capable of switching between connection and disconnection between the fuel cell and an electric load;
Control means for controlling the anode gas supply means and the cathode gas supply means;
Adjusting means for adjusting discharge from the fuel cell to the electrical load;
A fuel cell system comprising:
The fuel cell system includes:
A sealing valve for sealing the cathode of the fuel cell;
An anode gas circulation channel and circulation means capable of circulating the anode gas to the anode;
An anode gas discharge passage connected to the discharge side of the anode, and a purge valve capable of switching between opening and closing of the anode gas discharge passage to the outside;
With
The control means performs a step of closing the sealing valve before the start-up power generation mode of the fuel cell,
As the start-up power generation mode,
A first step of determining whether or not the anode gas is present in the anode gas flow path;
A second step of bringing the contactor into a connected state when it is determined in the first step that the anode gas is present in the anode gas flow path;
A third step of driving the circulating means after execution of the second step;
A fourth step of starting supply of the anode gas to the anode gas flow path and opening the purge valve after the execution of the third step;
A fifth step of closing the purge valve after execution of the fourth step;
A sixth step that is performed by opening the sealing valve and supplying the cathode gas to the cathode via the cathode gas flow path;
After execution of the sixth step, when it is determined in the first step that the anode gas is present in the anode gas flow path, and the voltage of the fuel cell detected by the voltage detection means reaches a predetermined voltage Starts power generation of the fuel cell, performs power generation of the fuel cell while maintaining the voltage below a predetermined voltage, and determines that the anode gas does not exist in the anode gas flow path in the first step. Is a seventh step not starting power generation of the fuel cell;
The fuel cell system characterized by performing. The fuel cell system is mounted on a vehicle,
A start input means for instructing start of the vehicle;
In the first step, the control means includes:
When the start of the vehicle is instructed by the start input means, the fuel cell stop standing time, the voltage of the fuel cell, the pressure of the anode, and the oxygen concentration of the anode or the cathode The fuel cell system according to claim 6, wherein it is determined that the anode gas is present in the anode gas flow path when at least one of them is in each predetermined state. The fuel cell system includes:
A cathode gas discharge passage connected to the cathode discharge side of the fuel cell;
A bypass flow path and a bypass valve capable of bypassing the cathode of the fuel cell and flowing the cathode gas to the cathode gas discharge flow path,
The fuel cell system according to claim 6 or 7, wherein the control means executes the sixth step while opening the bypass valve. 9. The control unit according to claim 6, wherein the control unit executes the seventh step so that the voltage of the fuel cell detected by the voltage detection unit falls within a predetermined range. The fuel cell system according to one. 10. The control unit according to claim 6, wherein the control unit executes the normal power generation mode instead of the power generation mode at startup when a predetermined time has elapsed from the start of execution of the power generation mode at startup. The fuel cell system according to one.

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