JP4839697B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system.

  Patent Documents 1 and 2 disclose conventional fuel cell systems. This fuel cell system includes a fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked. Each single cell is of a solid polymer membrane type (PEFC: Polymer Electrolyte Fuel Cells), and an electrolyte membrane made of an ion exchange resin is composed of a fuel electrode (also referred to as an anode electrode or a hydrogen electrode) and an air electrode (a cathode electrode, It is also called an oxygen electrode.) Each unit cell has a fuel chamber for supplying fuel such as hydrogen gas to the fuel electrode and an air chamber for supplying air containing oxygen to the air electrode.

  In addition, this type of fuel cell system includes a power storage device, a load device, and a control device. The power storage device is connected in parallel with the fuel cell stack and stores electric power output from the fuel cell stack. The load device is connected to each of the fuel cell stack and the power storage device, and is driven by electric power from at least one. The control device switches the connection with the fuel cell stack to the power storage device or the load device and controls the current value of the fuel cell stack.

In the conventional fuel cell system having such a configuration, during power generation of the fuel cell stack, fuel such as hydrogen gas is supplied to the fuel chamber of each single cell, and at the same time, air containing oxygen is supplied to the air chamber of each single cell. Supplied. Thereby, in each single cell, a fuel and oxygen react between a fuel electrode and an air electrode. Specifically, hydrogen ions obtained at the fuel electrode move to the air electrode side in the electrolyte membrane containing water in the form of protons ( H ₃ O ⁺ ), and react with oxygen in the air at the air electrode, Produce water. On the other hand, the electrons obtained at the fuel electrode move to the air electrode side through the load device. As a result of such a series of electrochemical reactions, electric power is output in each single cell. As a result, the fuel cell stack in which a plurality of single cells are stacked can output large electric power as a whole.

  In this fuel cell system, the control device directly supplies the power output from the fuel cell stack to the load device to drive the load device, and the control device switches the connection with the fuel cell stack to the power storage device, The power output from the battery stack is supplied to the power storage device to charge the power storage device. When the power output from the fuel cell stack decreases or stops, the control device switches the connection with the load device to the power storage device, and drives the load device with the power supplied from the power storage device. .

  By the way, in this fuel cell system, it is necessary to appropriately wet the electrolyte membrane of each single cell in order to maintain a good power generation state when the fuel cell stack generates power. This is because when the electrolyte membrane is dried, protons are inhibited from moving from the fuel chamber to the air chamber via the electrolyte membrane, and as a result, the power generation capability of the single cell is reduced. And if that state continues, it is because the performance degradation and failure which cannot be recovered may occur in the fuel cell stack.

  For this reason, in the fuel cell system of Patent Document 1, the electrolyte membrane is cooled or appropriately wetted by spraying liquid water onto the air supplied to the air chamber. In particular, when the temperature of the fuel cell stack rises, the cooling capacity against the temperature rise is insufficient, and the electrolyte membrane is likely to dry (hereinafter referred to as “dry up”). Then, the temperature of the fuel cell stack is measured, and if the temperature of the fuel cell stack is higher than the predetermined temperature, it is determined that the dry-up can occur, and the cooling capacity is controlled by independently controlling the amount of air and water supplied To increase. Thereby, in this fuel cell system, it is possible to suppress the occurrence of dry-up of the electrolyte membrane.

  In the fuel cell system of Patent Document 2, the humidity of the fuel supplied to the fuel chamber and the air supplied to the air chamber is increased by using a humidifier, so that the electrolyte membrane is appropriately moistened. . In particular, in this fuel cell system, it is determined that dry-up has occurred by measuring the amount of expansion and contraction of the fuel cell stack and the temperature after fixing the fuel cell stack in the stacking direction, and using a humidifier Increase humidification to increase cooling capacity. Thereby, also in this fuel cell system, dry-up can be suppressed.

Japanese Patent Laid-Open No. 2001-210348 JP 2001-332280 A

  However, the fuel cell systems disclosed in Patent Documents 1 and 2 only determine dry-up based on the temperature and expansion / contraction amount of the entire fuel cell stack. For this reason, even if dry-up progresses about one or a few single cells among the several single cells which comprise a fuel cell stack, the situation cannot be determined correctly. As a result, in this fuel cell system, it has been insufficient to suppress the dry-up at the single cell level and to suppress the performance degradation and durability deterioration at the single cell level.

The present invention has been made in view of the above-described conventional situation, and more accurately determines whether or not the fuel cell stack has a dry-up in which the voltage decreases with time. Providing a fuel cell system capable of suppressing deterioration in durability is an issue to be solved.

The fuel cell system according to claim 1 is a fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked;
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack and the power storage device;
In a fuel cell system comprising: a control device that switches connection to the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device comprises a single cell voltage detecting means for detecting a single cell voltage that is a voltage of each single cell at regular time intervals;
Current value detecting means for detecting the current value of the fuel cell stack at regular intervals;
Storage means for storing each single cell voltage and current value;
A single cell voltage comparison means for comparing each current single cell voltage and each previous single cell voltage;
For any of the single cells, if the current single cell voltage is lower than the previous single cell voltage, if the current current value is less than or equal to the previous current value, dry-up notification means for issuing a dry-up signal;
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and has warning means for issuing a warning signal. And

According to the test results of the inventors, it can be determined that dry-up has occurred in any single cell in the following cases. First, each single cell voltage and current value are detected at regular intervals, and the previous and current individual single cell voltages are compared. In any single cell, if the current single cell voltage is lower than the previous single cell voltage, there is a risk of dry-up if the current current value is equal to or less than the previous current value. If the state continues, it is accurately determined that the dry-up state in which the voltage decreases with time . As a result, in this fuel cell system, it is possible to suppress dry-up at the single cell level, and to suppress performance degradation and durability deterioration at the single cell level resulting therefrom.

  The warning means may be anything that emits a warning signal in the control device. If so, the control device can immediately take appropriate measures such as a dry-up countermeasure. The warning means informs the user of the fuel cell system or other outside that the dry-up condition has occurred immediately, or when the dry-up is not resolved even if the control device implements the dry-up measures. An anomaly may be reported.

A fuel cell system according to claim 2 is a fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked;
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack and the power storage device;
In a fuel cell system comprising: a control device that switches connection to the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device comprises a single cell voltage detecting means for detecting a single cell voltage that is a voltage of each single cell at regular time intervals;
Current value detecting means for detecting the current value of the fuel cell stack at regular intervals;
Average voltage calculating means for calculating an average voltage that is an average of the single cell voltages;
IV characteristic comparison means for comparing an average IV characteristic derived from the average voltage and current value and a preset reference IV characteristic;
A dry-up notification means for generating a dry-up signal when the average IV characteristic is lower than the reference IV characteristic;
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and has warning means for issuing a warning signal. And

According to the test results of the inventors, it can be determined that dry-up has occurred in any single cell in the following cases. First, each single cell voltage and current value are detected at regular intervals, and an average IV characteristic derived from an average voltage and current value that is an average of each single cell voltage is compared with a preset reference IV characteristic. . If the average IV characteristic is lower than the reference IV characteristic, there is a risk of dry-up. If the state continues, it is accurately determined that the dry-up state in which the voltage decreases with time . As a result, in this fuel cell system, it is possible to suppress dry-up at the single cell level, and to suppress performance degradation and durability deterioration at the single cell level resulting therefrom.

A fuel cell system according to claim 3 is a fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked, and
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack and the power storage device;
In a fuel cell system comprising: a control device that switches connection to the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device comprises a single cell voltage detecting means for detecting a single cell voltage that is a voltage of each single cell at regular time intervals;
Current value detecting means for detecting the current value of the fuel cell stack at regular intervals;
Storage means for storing each single cell voltage and current value;
An extracting means for extracting the single cell having the highest voltage and the single cell having the lowest voltage among all the single cells;
A single cell voltage comparing means for comparing a current voltage difference that is a current difference with a previous voltage difference that is a previous difference with respect to the single cell voltage associated with the two single cells;
If the current voltage difference is greater than the previous voltage difference, if the current value is less than or equal to the previous current value, dry-up notification means for issuing a dry-up signal;
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and has warning means for issuing a warning signal. And

According to the test results of the inventors, it can be determined that dry-up has occurred in any single cell in the following cases. First, each single cell voltage and current value are detected at regular intervals, and the single cell with the highest voltage and the single cell with the lowest voltage are extracted from all the single cells. The current voltage difference, which is the current difference, and the previous voltage difference, which is the previous difference, are compared with the single cell voltage. If the current voltage difference is larger than the previous voltage difference, there is a risk of dry-up if the current current value is less than or equal to the previous current value. If the state continues, it is accurately determined that the dry-up state in which the voltage decreases with time . As a result, in this fuel cell system, it is possible to suppress dry-up at the single cell level, and to suppress performance degradation and durability deterioration at the single cell level resulting therefrom.

Therefore, the fuel cell system according to claims 1 to 3 more accurately determines whether or not a dry-up in which the voltage decreases with the passage of time has occurred in the fuel cell stack, and the suppression, performance degradation, and durability degradation are determined. It can be suppressed.

The control device preferably has an air amount changing means for increasing the amount of air supplied to the fuel cell stack so that the fuel cell stack is cooled when a warning signal is issued. In this case, as the recovery operation after the dry-up in which the voltage decreases with the passage of time, the fuel cell stack can be quickly cooled by the air amount changing means, and the progress of the dry-up can be suppressed. Performance degradation and durability degradation can be suppressed.

  The degree of increase in the air amount by the air amount changing means is preferably adjusted appropriately in accordance with the amount of water sprayed into the air supplied to the fuel cell stack and the degree of humidification. For example, in the case of air containing moderately sprayed water, increasing the amount of air effectively vaporizes the water sprayed into the air in the air chamber, so the fuel cell stack can be effectively cooled by latent heat. Can do.

When the dry-up notification means does not issue a dry-up signal, the warning means preferably releases the warning signal, and the air amount changing means preferably reduces the amount of air supplied to the fuel cell stack. In this case, the fuel cell system after the transition to the recovery operation can be returned to the normal power generation state even once the dry-up state in which the voltage decreases with time .

  The control device preferably has a current value limiting means for limiting the current value of the fuel cell stack so that the fuel cell stack is cooled when a warning signal is issued. In this case, excessive output of the fuel cell stack can be suppressed and cooling can proceed.

  The current value limiting means may reduce the current value of the fuel cell stack by the power storage device and the load device. In this case, since the load device compensates the decrease in the output of the fuel cell stack with the electric power supplied from the power storage device, the driving force of the load device is not decreased while the cooling of the fuel cell stack is advanced.

The present invention may also be a method for operating a fuel cell system. The operation method of the first fuel cell system includes a fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked, and
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack and the power storage device;
In a method of operating a fuel cell system comprising: a control device that controls connection of the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device detects a single cell voltage that is a voltage of each single cell and a current value of the fuel cell stack at regular time intervals, and stores each single cell voltage and current value.
Compare each current single cell voltage with each previous single cell voltage,
For any of the single cells, if the current single cell voltage is lower than the previous single cell voltage, if the current current value is less than or equal to the previous current value, issue a dry-up signal,
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and a warning signal is issued.

The operation method of the second fuel cell system includes a fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked, and
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack and the power storage device;
In a method of operating a fuel cell system comprising: a control device that controls connection of the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device detects a single cell voltage that is a voltage of each single cell and a current value of the fuel cell stack at regular time intervals, calculates an average voltage that is an average of the single cell voltages,
Comparing an average IV characteristic derived from the average voltage and current value with a preset reference IV characteristic;
If the average IV characteristic is lower than the reference IV characteristic, issue a dry-up signal;
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and a warning signal is issued.

The operation method of the third fuel cell system includes a fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked, and
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack,
In a method of operating a fuel cell system comprising: a control device that controls connection of the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device detects a single cell voltage that is a voltage of each single cell and a current value of the fuel cell stack every predetermined time, and stores each single cell voltage and current value,
After extracting the single cell having the highest voltage and the single cell having the lowest voltage among all the single cells,
Compare the current voltage difference, which is the current difference, with the previous voltage difference, which is the previous difference, with respect to the single cell voltage associated with the two single cells,
If the current voltage difference is greater than the previous voltage difference, if the current current value is less than or equal to the previous current value, issue a dry-up signal,
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and a warning signal is issued.

  Embodiments 1 to 3 embodying the present invention will be described below with reference to the drawings.

  A fuel cell system 100 according to the first embodiment shown in FIG. 1 includes a fuel cell stack 1, a power storage device 2, a load device 3, and a control device 4.

  As shown in FIG. 2, the fuel cell stack 1 is formed by stacking a plurality of single cells 10 that output electric power by reacting fuel and air. The single cell 10 is of a solid polymer membrane type (PEFC: Polymer Electrolyte Fuel Cells), in which an electrolyte membrane 11a made of an ion exchange resin is sandwiched between a fuel electrode 11b and an air electrode 11c. The fuel electrode 11b is made of carbon integrally formed on one surface of the electrolyte membrane 11a, and the air electrode 11c is made of carbon integrally formed on the other surface of the electrolyte membrane 11a. Each unit cell 10 has a separator 12 between other unit cells 10 adjacent thereto. A fuel chamber 12a is formed on the fuel electrode 11b side of each separator 12, and hydrogen gas, which is a fuel gas, is supplied to the fuel electrode 11b by the fuel chamber 12a. On the other hand, an air chamber 12b is formed on the air electrode 11c side of each separator 12, and air containing oxygen is supplied to the air electrode 11c by the air chamber 12b.

  As shown in FIG. 1, the fuel cell stack 1 is assembled together with other components to constitute a fuel cell system 100.

  The following various components are connected to the supply port 21a and the discharge port 21b provided in the fuel chamber 12a of the fuel cell stack 1 to supply hydrogen gas into the fuel chamber 12a and from the fuel chamber 12a. The exhaust hydrogen gas can be discharged.

  There is a hydrogen tank 50 on the most upstream side of the supply port 21a, and a pipe 51 is provided between the hydrogen tank 50 and the supply port 21a. The pipe 51 includes a hydrogen source electromagnetic valve 61a, a hydrogen supply pressure regulator 61b, and a hydrogen supply electromagnetic valve 61c from the hydrogen tank 50 side.

  A pipe 52 is provided from the discharge port 21 b to the connection point B, and a pipe 53 is provided from the connection point B to the duct 91. A pipe 54 is provided from the connection point B to the connection point A in the middle of the pipe 51.

  The pipe 53 has a hydrogen exhaust solenoid valve 63 for discharging exhaust hydrogen gas from the exhaust port 21b. The pipe 54 has a hydrogen circulation solenoid valve 64 for resupplying the exhaust hydrogen gas from the supply port 21a.

  An air manifold 42 that takes in air is provided above the fuel cell stack 1. An air intake fan 41 having a filter 41a is connected to the air manifold 42 so that air can be supplied into the air chamber 12b. The air manifold 42 is provided with a water injection nozzle 99. The water injection nozzle 99 is connected to a water tank 97 in which a level gauge 97 a is built by a pipe 98. The pipe 98 includes a filter 98 a and a water direct injection pump 83.

  Further, below the fuel cell stack 1, an air discharge path 90 having a temperature sensor 90 a, a condenser 92, a condenser fan 93, and a duct 91 that guides the discharged air from the air discharge path 90 to the condenser 92. Are provided so that air can be discharged from the air chamber 12b. The condenser 92 is capable of separating air and water. The condenser 92 includes a pipe 94 for discharging the separated air to the atmosphere, a filter 94a, and a temperature sensor 94b. A pipe 96 for transporting the water to the water tank 97 and a water recovery pump 82 are provided.

  The fuel cell stack 1, the hydrogen source solenoid valve 61a, the hydrogen supply pressure regulator 61b, the hydrogen supply solenoid valve 61c, the hydrogen exhaust solenoid valve 63, and the hydrogen circulation solenoid valve 64 are electrically connected to the control device 4 and can be controlled. Has been. Further, the air suction fan 41, the level gauge 97a, the water direct injection pump 83, the temperature sensor 90a, the condenser fan 93, and other components are also electrically connected to the control device 4 and can be controlled.

  Next, the power storage device 2, the load device 3, and the control device 4 will be described.

  As shown in FIG. 1, the power storage device 2 is connected in parallel with the fuel cell stack 1 and stores electric power output from the fuel cell stack 1. As the power storage device 2, general power storage means such as a capacitor or a secondary battery can be employed.

  The load device 3 is connected to the fuel cell stack 1 and the power storage device 2, respectively, and is driven by electric power from at least one. The load device 3 includes an inverter (not shown) and an electric motor (not shown), and can drive an automobile on which the fuel cell system 100 is mounted.

  The control device 4 switches the connection with the fuel cell stack 1 to the power storage device 2 or the load device 3 and controls the current value of the fuel cell stack 1.

  Specifically, relays 45a and 45d, a diode 45b, and an IPM (Intelligent Power Module) 45c constituting a part of the control device 4 are connected to the terminal 1a on the fuel electrode 11a side of the fuel cell stack 1.

  By the cooperative operation of the relays 45a and 45d, the connection with the fuel cell stack 1 can be switched to the power storage device 2 or the load device 3, and the connection between the fuel cell stack 1, the power storage device 2 and the load device 3 can be disconnected. It is said that. Further, the current from the power storage device 2 to the fuel cell stack 1 is interrupted by the diode 45b. Further, the IPM 45c can control the current value of the fuel cell stack 1 by adjusting the sharing of power supply between the fuel cell stack 1 and the power storage device 2 according to the situation.

  Further, as shown in the program of the dry-up determination routines S101 to S113 in FIG. 3, the control device 4 includes single cell voltage detection means S102 and S104, current value detection means S103 and S105, storage means S102 to S105, single cell voltage. It has comparison means S106, dry-up notification means S107, S108, and warning means S109, S110.

  The single cell voltage detection means S102 and S104 are each a single cell voltage Vc1 (m) or Vc2 (m) which is a voltage of each single cell 10 by a voltmeter (not shown) connected to each single cell 10 at a predetermined time. ,..., Vcp (m) is detected (p: total number of single cells, m: number of detection processing executions).

  The current value detection means S103, S105 detects the current value Is (m) of the fuel cell stack 1 at regular intervals by an ammeter (not shown) connected to the fuel cell stack 1.

  The storage means S102 to S105 store the measured single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m) and the current value Is (m).

  The single cell voltage comparison means S106 is configured to calculate the current single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m) and the previous single cell voltages Vc1 (m−1), Vc2 (m−1). ,..., Vcp (m−1) are compared for each single cell 10.

  The dry-up notification means S107, S108 determines that the current single cell voltage Vcq (m) is the previous single cell voltage for any single cell 10 (for example, the qth single cell 10 out of the total number p of single cells). If it is lower than Vcq (m−1), a dry-up signal is generated if the current value Is (m) is equal to or less than the previous current value Is (m−1).

The warning means S109 and S110 issue a warning signal when it is determined that a dry-up in which the voltage decreases with the passage of time has occurred when the dry-up signal is continuously issued for a predetermined reference number or more. is there.

  Furthermore, the control device 4 includes air amount changing means S131 to S134 and a current value limiting means S135 as shown in the dry up countermeasure routine program of FIG.

  The air amount changing means S131 to S134 increase the amount of air supplied to the fuel cell stack 1 so that the fuel cell stack 1 is cooled by increasing the rotation speed of the air intake fan 41 when a warning signal is issued. It is something to be made. The degree of increase in the air amount by the air amount changing means S131 to S134 is appropriately adjusted according to the amount of water sprayed from the water injection nozzle 99 into the air supplied to the fuel cell stack 1. In the case of air containing moderately mist-like water, if the amount of air is increased, the water sprayed in the air is efficiently vaporized in the air chamber 12b, so that the fuel cell stack 1 is effectively cooled by latent heat. be able to.

Further, when the dry-up notification means S107 and S108 do not issue a dry-up signal, the air amount changing means S131 to S134 release the warning signal by the warning means S109 and S110 and reduce the amount of air supplied to the fuel cell stack 1. It is supposed to let you. By doing so, the fuel cell system 100 after the transition to the recovery operation can be returned to the normal power generation state even once the dry-up state in which the voltage decreases with time .

  The current value limiting means S135 controls the above-described relays 45a, 45d, IPM 45c, etc. when a warning signal is issued, and limits the current value of the fuel cell stack 1 so that the fuel cell stack 1 is cooled. It is. By doing so, it is possible to suppress excessive output of the fuel cell stack 1 and to proceed with cooling. Further, in this case, since the load device 3 compensates the decrease in the output of the fuel cell stack 1 with the electric power supplied from the power storage device 2, it is possible to prevent the driving force of the load device 3 from being decreased. .

In the fuel cell system 100 of Example 1 having such a configuration, as shown in FIG. 2, fuel such as hydrogen gas is supplied to the fuel chambers 12 a of each single cell 10 during power generation of the fuel cell stack 1. At the same time, air containing oxygen is supplied to the air chamber 12b of each single cell 10. Thereby, in each single cell 10, a fuel and oxygen react between the fuel electrode 11b and the air electrode 11c. Specifically, the hydrogen ions obtained at the fuel electrode 11b move to the air electrode 11c side in the electrolyte membrane 11a containing moisture in the form of protons ( H ₃ O ⁺ ), and oxygen in the air at the air electrode 11c. Reacts with water to form water. On the other hand, the electrons obtained at the fuel electrode 11b move to the air electrode 11c side through the load device 3. As a result of such a series of electrochemical reactions, electric power is output in each single cell 10. As a result, the fuel cell stack 1 in which a plurality of single cells 10 are stacked can output large electric power as a whole.

  During this time, as shown in FIG. 1, a hydrogen tank is provided by piping 51, 52, 53, 54, a hydrogen source solenoid valve 61a, a hydrogen supply regulator 61b, a hydrogen supply solenoid valve 61c, a hydrogen exhaust solenoid valve 63, and a hydrogen circulation solenoid valve 64. Hydrogen gas is supplied from 51 to the supply port 21a, or exhaust hydrogen gas is re-supplied from the discharge port 21b to the supply port 21a. Also, the piping 52 and 53 and the hydrogen exhaust electromagnetic valve 63 allow the exhaust hydrogen gas and the water produced by the electrochemical reaction to be intermittently transferred from the discharge port 21b of the fuel chamber 12a to the condenser 92 via the duct 91. Or cause an electrochemical reaction to occur continuously.

  Further, the water in the water tank 97 is pumped by the water direct injection pump 83 and injected from the water injection nozzle 99 into the air manifold 42. Thereby, drying of the air electrode 11c and the electrolyte membrane 11a is suppressed, and the fuel cell stack 1 is cooled while being appropriately moistened. Further, air containing water discharged from the air chamber 12 b of the fuel cell stack 1 is transferred from the air discharge path 90 to the condenser 92 via the duct 91. The air separated by the condenser 92 is discharged from the pipe 94 to the atmosphere, and the separated water is collected in the water tank 97 by the water collection pump 82. Similarly, the exhaust hydrogen gas and the generated water transferred to the condenser 92 via the duct 91 are separated into hydrogen and water, the hydrogen is discharged into the atmosphere together with the air, and the water is collected in the water tank 97. The

In the fuel cell system 100 operating in this way, the control device 4 executes the above-described dry-up determination routines S101 to S113 according to the program shown in FIG. 3 when the fuel cell stack 1 generates power. Then, the control device 4 issues a warning signal when it is determined that the fuel cell stack 1 is a dry-up in which the voltage decreases with time .

  That is, when the dry-up determination routines S101 to S113 are executed, initial settings are made in S101 to S103. In step S101, the detection processing execution number m and the dry-up signal continuous generation number n are set to zero. In S102, single cell voltages Vc1 (0), Vc2 (0),..., Vcp (0), which are voltages of each single cell 10, are detected and stored in the storage means. Next, in S103, the current value Is (0) of the fuel cell stack 1 is detected and stored in the storage means.

  In S104 to S113, the dry-up detection process is repeated. In S104, the single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m), which are the voltages of the single cells 10, are detected and stored in the storage means after a predetermined time has elapsed since the previous measurement. In S105, the current value Is (m) of the fuel cell stack 1 is detected after a predetermined time has elapsed since the previous measurement and stored in the storage means.

  In S106, the current single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m) and the previous single cell voltages Vc1 (m−1), Vc2 (m−1),. m−1) is compared for each single cell 10. As a result, in S106, the current single cell voltage Vcq (m) is set to the previous single cell voltage Vcq (m) for any single cell 10 (for example, the qth single cell 10 out of the total number p of single cells). If the current value Is (m) is lower than the previous current value Is (m-1) in S107, a dry-up signal is issued in S108. At this time, if a dry-up signal is continuously generated, the number of consecutive dry-up signal generations n is incremented by 1 in S108. On the other hand, if the determination formula is not satisfied in S106 or S107 and the generation of the dry-up signal is interrupted, the number of consecutive dry-up signal generations n is reset to 0 in S111.

In S109, if the number of consecutive dry-up signal generations n is equal to or greater than the reference number, it is determined that a dry-up in which the voltage decreases with time has elapsed , and a warning signal is generated in S110. As a result, the fuel cell system 100 proceeds to the dry-up countermeasure routines S131 to S135 that are predetermined recovery operations.

  On the other hand, if the number of consecutive dry-up signal occurrences n is smaller than the reference number in S109, it is determined in S112 whether to continue the detection process. If the detection process is continued, the detection process is performed in S113. The count m is incremented by 1, and the detection process is repeated again from S104.

  As shown in FIG. 4, the control device 4 performs the recovery operation of the fuel cell system 100 as described below after shifting to the dry-up countermeasure routines S <b> 131 to S <b> 135.

  In S131, the rotational speed of the air suction fan 41 is increased to increase the amount of air supplied to the fuel cell stack 1, and the water sprayed into the air from the water injection nozzle 99 is efficiently vaporized in the air chamber 12b. Thus, the fuel cell stack 1 is effectively cooled by generating latent heat.

In S132, the result of the dry-up detection process in the program of the dry-up determination routines S101 to S113 in FIG. 3 is referred. As a result, when the dry-up in which the voltage decreases with the passage of time is improved, In S133, the amount of air supplied to the fuel cell stack 1 is decreased and returned to the original amount of air. On the other hand, if the dry-up in which the voltage decreases with time has not been improved, the process proceeds to S135.

  In S135, the relays 45a and 45d, the IPM 45c, etc. are controlled to limit the current value of the fuel cell stack 1 so that the fuel cell stack 1 is cooled. Thereby, excessive output of the fuel cell stack 1 is suppressed, and cooling proceeds. At this time, since the load device 3 compensates for the decrease in the output of the fuel cell stack 1 by the electric power supplied from the power storage device 2, the driving force of the load device 3 is not decreased.

Back in S133, the amount of air supplied to the fuel cell stack 1 is reduced and returned to the original amount of air, and then in S134, the dry-up detection process in the program of the dry-up determination routines S101 to S113 in FIG. As a result, if the dry-up in which the voltage decreases with time has not occurred, it is determined that the dry-up has been completely eliminated, and the dry-up countermeasure is terminated. Here, if the dry-up in which the voltage decreases with the passage of time has occurred again, the process returns to S131 and the dry-up countermeasure is repeated.

  By such a procedure, the fuel cell system 100 of Example 1 can suppress the dry-up at the single cell level and the performance degradation and durability degradation at the single cell level resulting therefrom.

  Next, a confirmation test was performed in a state where the fuel cell system 100 of Example 1 described above was mounted on an automobile. The measurement results are shown in FIG.

  FIG. 5 shows how voltages Vc1 (m), Vc2 (m),..., Vc5 (m) of each single cell 10 (total number of single cells p = 5) are detected and how they change over time. It is the graph which showed. The changes over time of Vc1 (m), Vc2 (m),..., Vc5 (m) are indicated by curves G1, G2,. The current output from the fuel cell stack 1 is instructed by the load device 3 so that the voltage is stepped with time. Therefore, the voltages Vc1 (m), Vc2 (m),..., Vc5 (m) of each single cell 10 also tend to decrease basically in a stepped manner.

Here, for example, in the region T in the graph, among the single cells 10, the single cell 10 indicated by the curve G <b> 5 is in a state in which the dry-up in which the voltage decreases with time has occurred remarkably. On the other hand, the unit cell 10 shown in curve G1, a condition that the dried-up is hardly caused. Then, as can be seen from the curve G5, the the single cell dry-up occurs 10, over time, shows a tendency that the voltage drops. For this reason, if the above-described dry-up determination routines S101 to S113 are applied to this measurement result, the determination formulas of S106 to S107 are continuously established, and the dry-up is determined. Thus, the dry-up determination routines S101 to S113 of the first embodiment can reliably detect the dry-up at the single cell level.

Therefore, the fuel cell system 100 according to the first embodiment more accurately determines whether or not a dry-up in which the voltage decreases with time has occurred in the fuel cell stack 1, and suppresses the suppression as well as performance degradation and durability degradation. Have been able to.

Further, in the fuel cell system 100, the control device 4, since they have air amount changing means S131～S134, as the recovery operation after the dry-up, the fuel cell stack 1 by the air amount changing means S131～S134 While cooling rapidly, the progress of the dry-up can be suppressed, and the performance deterioration and durability deterioration of the fuel cell stack 1 can be suppressed. Further, by decreasing the amount of air in S133, the after dry-up is eliminated, and it is possible to return the fuel cell system 100 in the normal power generation state.

  Furthermore, since the control device 4 has the current value limiting means S135, the excessive output of the fuel cell stack 1 can be suppressed and the cooling can proceed. In addition, since the current value limiting means S135 reduces the current value of the fuel cell stack 1 by the power storage device 2 and the load device 3, the load device 3 causes the output of the fuel cell stack 1 to decrease from the power storage device 2. Since it is supplemented by the supplied electric power, it is possible to realize that the driving force of the load device 3 is not reduced while the cooling of the fuel cell stack 1 proceeds.

  In the fuel cell system of the second embodiment, the dry-up determination routines S201 to S213 shown in FIG. 6 are adopted with respect to the dry-up determination routines S101 to S113 of the fuel cell system 100 of the first embodiment. Since other configurations are the same as those of the fuel cell system 100 of the first embodiment, the description thereof is omitted.

  In the fuel cell system according to the second embodiment, as shown in the program of the dry-up determination routines S201 to S213 in FIG. 6, the control device 4 includes a single cell voltage detection unit S202, a current value detection unit S203, an average voltage calculation unit S204, IV characteristic comparison means S205, S206, dry-up notification means S208, and warning means S209, S210.

  The single cell voltage detection means S202 is a single cell voltage Vc1 (m), Vc2 (m),..., Which is a voltage of each single cell 10 by a voltmeter (not shown) connected to each single cell 10 at regular intervals. , Vcp (m) is detected (p: total number of single cells, m: number of detection processing executions).

  The current value detection means S204 detects the current value Is (m) of the fuel cell stack 1 at regular intervals by an ammeter (not shown) connected to the fuel cell stack 1.

  The average voltage calculation means S203 calculates an average voltage VcA (m) that is an average of the single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m).

As shown in the graph of FIG. 7, the IV characteristic comparison means S205 and S206 are preliminarily calculated with the average IV characteristic Z (Z is a point on the curve Gc) derived from the average voltage VcA (m) and the current value Is (m). The set reference IV characteristic Gs (Gs is a curve) is compared. The reference IV characteristic Gs is set in advance based on data measured by the performance test of the fuel cell stack 1. A curve Gc is an example of the IV characteristic when the fuel cell stack 1 is in a dry-up state where the voltage decreases with time .

  The dry-up notification unit S208 generates a dry-up signal when the average IV characteristic Z is lower than the reference IV characteristic Gs.

The warning means S209 and S210, when the dry-up signal is continuously issued for a predetermined reference number or more, determines that a dry-up in which the voltage decreases with time has occurred, and issues a warning signal. is there.

  The fuel cell system according to the second embodiment having such a configuration is also mounted on an automobile and has the same effects as the fuel cell system 100 according to the first embodiment.

Then, the control unit 4, when the power generation of the fuel cell stack 1, in accordance with the program shown in FIG. 6, to implement the dry-up determination routine S 2 01~S 2 13 described above. Then, the control device 4 issues a warning signal when it is determined that the fuel cell stack 1 is a dry-up in which the voltage decreases with time .

  That is, when the dry-up determination routines S201 to S213 are executed, the detection process execution count m and the dry-up signal continuous occurrence count n are set to 0 as initial settings in S201.

  In S202 to S213, the dry-up detection process is repeated. In S202, single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m), which are voltages of each single cell 10, are detected after a predetermined time has elapsed since the previous measurement. In S203, the current value Is (m) of the fuel cell stack 1 is detected after a predetermined time has elapsed since the previous measurement. In S204, an average voltage VcA (m) that is an average of the single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m) is calculated. In S205, an average IV characteristic Z is derived from the average voltage VcA (m) and the current value Is (m).

  In S206, the average IV characteristic Z is compared with a preset reference IV characteristic Gs (Gs is a curve). As a result, if the average IV characteristic Z is lower than the preset reference IV characteristic Gs in S206, a dry-up signal is issued in S208. At this time, if the dry-up signal is continuously generated, the number of consecutive dry-up signal generations n is incremented by 1 in S208. On the other hand, if the determination formula is not satisfied in S206 and the generation of the dry-up signal is interrupted, the number of consecutive dry-up signal generations n is reset to 0 in S211.

Then, in S209, when the dry-up signal continuous occurrence number n is equal to or more than the reference number, it is determined that dry-up in which the voltage decreases with the passage of time has occurred, and in S210, a warning signal is generated. As a result, the fuel cell system shifts to dry-up countermeasure routines S131 to S135 that are predetermined recovery operations.

  On the other hand, in S209, if the number of consecutive dry-up signals n is smaller than the reference number, it is determined in S212 whether to continue the detection process. If the detection process is continued, the detection process is performed in S213. The number m is incremented by 1, and the detection process is repeated again from S202.

  By such a procedure, the fuel cell system of Example 2 can also suppress the dry-up at the single cell level and the performance degradation and durability deterioration at the single cell level resulting therefrom.

Therefore, the fuel cell system of the second embodiment also determines more accurately whether or not the fuel cell stack 1 has a dry-up in which the voltage decreases with time , as in the fuel cell system 100 of the first embodiment. The suppression and performance degradation and durability degradation can be suppressed.

  In the fuel cell system of the third embodiment, the dry-up determination routines S301 to S313 shown in FIG. 8 are adopted with respect to the dry-up determination routines S101 to S113 of the fuel cell system 100 of the first embodiment. Since other configurations are the same as those of the fuel cell system 100 of the first embodiment, the description thereof is omitted.

  In the fuel cell system according to the third embodiment, as shown in the program of the dry-up determination routines S301 to S313 in FIG. 8, the control device 4 includes single cell voltage detection means S302 and S304, current value detection means S303 and S305, storage means. S302 to S305, extraction means S305a, single cell voltage comparison means S306, dry-up notification means S307 and S308, and warning means S309 and S310.

  The single cell voltage detection means S302 and S304 are operated by a voltmeter (not shown) connected to each single cell 10, and single cell voltages Vc1 (m) and Vc2 (m) that are voltages of the single cells 10 at regular intervals. .., Vcp (m) is detected.

  The current value detection means S303 and S305 are for detecting the current value Is (m) of the fuel cell stack 1 at regular intervals by an ammeter (not shown) connected to the battery cell stack 1.

  The storage means S302, S303, S304, and S305 store the detected single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m) and the current value Is (m).

  The extraction unit S305a extracts the single cell 10 having the highest voltage among all the single cells 10 as X and the single cell 10 having the lowest voltage as Y (X and Y are the total number p of single cells 10). The Xth and Yth cells).

  The single cell voltage comparison means S306 is a current voltage difference that is a current difference with respect to the single cell voltages VcX (m) and VcY (m) related to these two (that is, the Xth and Yth) single cells 10. (VcX (m) −VcY (m)) is compared with the previous voltage difference (VcX (m−1) −VcY (m−1)) which is the previous difference.

  When the current voltage difference (VcX (m) −VcY (m)) is larger than the previous voltage difference (VcX (m−1) −VcY (m−1)), the dry-up notification means S307 and S308 If Is (m) is less than or equal to the previous current value Is (m−1), a dry-up signal is generated.

The warning means S309 and S310, when a dry-up signal is continuously issued for a predetermined reference number or more, determines that a dry-up in which the voltage decreases with time has occurred, and issues a warning signal. is there.

  The fuel cell system according to the third embodiment having such a configuration is also mounted on an automobile and exhibits the same operational effects as the fuel cell system 100 according to the first embodiment.

Then, the control device 4 executes the above-described dry-up determination routines S301 to S313 according to the program shown in FIG. 8 when the fuel cell stack 1 generates power. Then, the control device 4 issues a warning signal when it is determined that the fuel cell stack 1 is a dry-up in which the voltage decreases with time .

  That is, when the dry-up determination routines S301 to S313 are executed, the detection processing execution count m and the dry-up signal continuous occurrence count n are set to 0 as initial settings in S301. In S302, single cell voltages Vc1 (0), Vc2 (0),..., Vcp (0), which are voltages of each single cell 10, are detected and stored in the storage means. Next, in S303, the current value Is (0) of the fuel cell stack 1 is detected and stored in the storage means.

  In S304 to S313, the dry-up detection process is repeated. In S304, the single cell voltages Vc1 (m), Vc2 (m),..., Vcp (m), which are voltages of the single cells 10, are detected and stored in the storage unit after a predetermined time has elapsed since the previous measurement. In S305, the current value Is (m) of the fuel cell stack 1 is detected and stored in the storage means after a predetermined time has elapsed since the previous measurement. Further, in S305a, the single cell 10 having the highest voltage among all the single cells 10 is extracted as X, and the single cell 10 having the lowest voltage is extracted as Y.

  In S306, a current voltage difference (VcX (m) −VcY (m)) that is a current difference with respect to the single cell voltages VcX (m) and VcY (m) related to the Xth and Yth single cells 10; The previous voltage difference (VcX (m−1) −VcY (m−1)), which is the previous difference, is compared. As a result, if the current voltage difference (VcX (m) −VcY (m)) is larger than the previous voltage difference (VcX (m−1) −VcY (m−1)) in S306, the current current value is determined in S307. If Is (m) is equal to or less than the previous current value Is (m-1), a dry-up signal is issued in S308. At this time, if a dry-up signal is continuously generated, the number of consecutive dry-up signals generated n is incremented by 1 in S308. On the other hand, if the determination formula is not satisfied in S306 or S307 and the generation of the dry-up signal is interrupted, the number of consecutive dry-up signal generations n is reset to 0 in S311.

Then, in S309, when the dry-up signal continuous occurrence number n is equal to or more than the reference number, it is determined that dry-up in which the voltage decreases with the passage of time has occurred, and in S310, a warning signal is generated. As a result, the fuel cell system shifts to dry-up countermeasure routines S131 to S135 that are predetermined recovery operations.

  On the other hand, in S309, if the number n of consecutive dry-up signal occurrences is smaller than the reference number, it is determined in S312 whether to continue the detection process. If the detection process is continued, the detection process is performed in S313. The number m is incremented by 1, and the detection process is repeated again from S304.

  By such a procedure, the fuel cell system of Example 3 can also suppress the dry-up at the single cell level and the performance degradation and durability deterioration at the single cell level resulting therefrom.

  Here, the operation of the dry-up determination routines S301 to S313 of the third embodiment will be described based on the measurement result of FIG. 5 described also in the fuel cell system 100 of the first embodiment.

For example, in the region T in the graph, among the single cells 10, the single cell 10 indicated by the curve G <b> 5 is in a state in which the dry-up in which the voltage decreases with time has occurred remarkably. On the other hand, the unit cell 10 shown in curve G1, a condition that the dried-up is hardly caused. Then, as can be seen from the curve G5, the the single cell dry-up occurs 10, over time, shows a tendency that the voltage drops. Therefore, if the above-described dry-up determination routines S301 to S313 are applied to this measurement result, the single cell 10 indicated by the curve G1 is the single cell having the highest voltage in S305a, and the single cell 10 indicated by the curve G5 is displayed. Is extracted as a single cell having the lowest voltage. In the basin T, the curve G1 is not decreasing, whereas the curve G5 is decreasing gradually. Therefore, the determination formulas of S306 and S307 are established, and it is determined that the dry-up occurs. Become. Thus, the dry-up determination routines S301 to S313 of the third embodiment can also reliably detect dry-up at the single cell level.

Therefore, the fuel cell system of the third embodiment also determines more accurately whether or not the fuel cell stack 1 has undergone a dry-up in which the voltage decreases with time , similar to the fuel cell system 100 of the first embodiment. The suppression and performance degradation and durability degradation can be suppressed.

  In the above, the present invention has been described with reference to the first to third embodiments. However, the present invention is not limited to the first to third embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  The present invention is applicable to a fuel cell system.

1 is a schematic configuration diagram according to a fuel cell system of Example 1. FIG. 1 is a schematic cross-sectional view of a stack of fuel cell stacks according to a fuel cell system of Example 1. FIG. 3 is a flowchart of a fuel cell stack dry-up determination routine according to the fuel cell system of Example 1; 3 is a flowchart of a fuel cell stack dry-up countermeasure routine according to the fuel cell system of Example 1; 5 is a graph showing a relationship between elapsed time and each single cell voltage of the fuel cell stack in the fuel cell system of Example 1; 7 is a flowchart of a fuel cell stack dry-up determination routine according to the fuel cell system of Example 2. 6 is a graph showing IV characteristics of a fuel cell stack according to the fuel cell system of Example 2. 10 is a flowchart of a fuel cell stack dry-up countermeasure routine according to the fuel cell system of Example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Single cell 1 ... Fuel cell stack 2 ... Power storage apparatus 3 ... Load apparatus 4 ... Control apparatus 100 ... Fuel cell system Vc1 (m), Vc2 (m), ..., Vcp (m) ... Single cell voltage S102, S104, S202, S302, S304 ... Single cell voltage detection means S103-S105, S303-305 ... Storage means S106, S306 ... Single cell voltage comparison means S107, S108, S208, S307, S308 ... Dry-up notification means S109, S110, S209, S210, S309, S310 ... Warning means S204 ... Average voltage calculation means S205, S206 ... IV characteristic comparison means S305a ... Extraction means S131-S134 ... Air amount changing means S135 ... Current value limiting means n ... Number of times the dry-up signal is continuously generated

Claims (7)

A fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked; and
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack and the power storage device;
In a fuel cell system comprising: a control device that switches connection to the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device comprises a single cell voltage detecting means for detecting a single cell voltage that is a voltage of each single cell at regular time intervals;
Current value detecting means for detecting the current value of the fuel cell stack at regular intervals;
Storage means for storing each single cell voltage and current value;
A single cell voltage comparison means for comparing each current single cell voltage and each previous single cell voltage;
For any of the single cells, if the current single cell voltage is lower than the previous single cell voltage, if the current current value is less than or equal to the previous current value, dry-up notification means for issuing a dry-up signal;
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and has warning means for issuing a warning signal. A fuel cell system. A fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked; and
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack and the power storage device;
In a fuel cell system comprising: a control device that switches connection to the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device comprises a single cell voltage detecting means for detecting a single cell voltage that is a voltage of each single cell at regular time intervals;
Current value detecting means for detecting the current value of the fuel cell stack at regular intervals;
Average voltage calculating means for calculating an average voltage that is an average of the single cell voltages;
IV characteristic comparison means for comparing an average IV characteristic derived from the average voltage and current value and a preset reference IV characteristic;
A dry-up notification means for generating a dry-up signal when the average IV characteristic is lower than the reference IV characteristic;
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and has warning means for issuing a warning signal. A fuel cell system. A fuel cell stack in which a plurality of single cells that output electric power by reacting fuel and air are stacked; and
A power storage device connected in parallel with the fuel cell stack and storing electric power output from the fuel cell stack;
A load device connected to each of the fuel cell stack and the power storage device and driven by power from at least one of the fuel cell stack and the power storage device;
In a fuel cell system comprising: a control device that switches connection to the fuel cell stack to the power storage device or the load device and controls a current value of the fuel cell stack;
The control device comprises a single cell voltage detecting means for detecting a single cell voltage that is a voltage of each single cell at regular time intervals;
Current value detecting means for detecting the current value of the fuel cell stack at regular intervals;
Storage means for storing each single cell voltage and current value;
An extracting means for extracting the single cell having the highest voltage and the single cell having the lowest voltage among all the single cells;
A single cell voltage comparing means for comparing a current voltage difference that is a current difference with a previous voltage difference that is a previous difference with respect to the single cell voltage associated with the two single cells;
If the current voltage difference is greater than the previous voltage difference, if the current value is less than or equal to the previous current value, dry-up notification means for issuing a dry-up signal;
When the dry-up signal is continuously issued for a predetermined reference number or more, it is determined that a dry-up in which the voltage decreases with the passage of time has occurred, and has warning means for issuing a warning signal. A fuel cell system.   4. The control device according to claim 1, further comprising an air amount changing means for increasing an amount of air supplied to the fuel cell stack so that the fuel cell stack is cooled when the warning signal is issued. The fuel cell system according to claim 1.   The said warning means cancels | releases the said warning signal when the said dry-up notification means does not emit the said dry-up signal, The said air quantity change means reduces the air quantity supplied to the said fuel cell stack. Fuel cell system.   6. The control device according to claim 1, further comprising a current value limiting means for limiting a current value of the fuel cell stack so that the fuel cell stack is cooled when the warning signal is issued. The fuel cell system described.   The fuel cell system according to claim 6, wherein the current value limiting means decreases the current value of the fuel cell stack by the power storage device and the load device.

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