JP5899000B2 - Method for judging leakage abnormality of fuel cell system - Google Patents

Description

  The present invention relates to a leakage abnormality determination method for a fuel cell system.

  Conventionally, as a fuel cell mounted on a vehicle, for example, a membrane electrode structure is formed by sandwiching a solid polymer electrolyte membrane from both sides with an anode electrode and a cathode electrode, and a pair of separators are arranged on both sides of the membrane electrode structure. A flat unit fuel cell (hereinafter referred to as a unit cell) is configured, and a plurality of unit cells are stacked to form a fuel cell stack (hereinafter referred to as a fuel cell).

  Specifically, hydrogen gas is supplied as a fuel to the anode flow channel facing the anode electrode, and air is supplied as an oxidant to the cathode flow channel facing the cathode electrode. As a result, hydrogen ions generated by the catalytic reaction at the anode electrode pass through the solid polymer electrolyte membrane and move to the cathode electrode, causing an electrochemical reaction with oxygen in the air at the cathode electrode, thereby generating power.

  In a fuel cell system equipped with such a fuel cell, if oxygen remains in the flow path when power generation is stopped, there is a problem that the fuel cell deteriorates and power generation stability at the next system startup decreases. . Therefore, a technique has been proposed in which a sealing valve is provided in each channel in order to shut off each channel in a state where the molar ratio of hydrogen and oxygen satisfies a desired condition.

JP 2006-185886 A JP 2010-80166 A

  However, when the sealing valve is deteriorated and the seal portion is damaged, the sealing performance of the sealing valve is lowered. In addition to this, when the pipe joint is damaged or when the fastening load of the fuel cell stack is reduced, the sealing performance of each flow path deteriorates, and the flow path sealing of the fuel cell system is reduced. Leakage abnormality occurs. When a leakage abnormality occurs in the anode channel, the hydrogen gas flows out from the anode channel and the air flows in while the fuel cell power generation is stopped. As a result, when the fuel cell is next started, the fuel cell is started in a state where air is abundant (oxygen-rich) in both electrodes as the first gas state (hereinafter referred to as “air / air start”). When the number of times of air / air activation is increased, there is a problem that the catalyst constituting both electrodes is deteriorated. On the other hand, if a leakage abnormality occurs in the cathode flow channel seal, air flows into the cathode flow channel while the fuel cell is stopped, the fuel cell deteriorates, and power generation stability at the next system startup is reduced. There is a problem that it decreases. Therefore, it is important to detect the occurrence of leakage abnormality in each flow channel at an early stage.

  Japanese Patent Application Laid-Open No. H10-228707 describes performing a determination of an airtight abnormality of the fuel circulation system during fuel cell power generation. However, the cited document 1 does not describe detecting a leakage abnormality while the fuel cell is stopped. When the fuel cell is stopped, it is necessary to consider not only the fuel circulation system but also the leakage abnormality of the cathode electrode.

  Patent Document 2 describes that an abnormality of the fuel cell system is detected based on a change in the voltage of the fuel cell. However, it is difficult to determine a leakage abnormality only by the voltage of the fuel cell. For example, when the sealing performance of the anode-side sealing valve is greatly reduced, the anode flow path becomes oxygen-rich, the cathode flow path becomes hydrogen-rich, and inversion (reverse potential) occurs. When this inversion occurs only in the unit cells near the connection portion of the gas manifold, the total voltage of the fuel cell approaches 0V. However, even when the gas crossover across the electrolyte membrane increases, both the anode channel 21 and the cathode channel 22 become hydrogen-rich or oxygen-rich, so the total voltage of the fuel cell 11 becomes 0V. . In this way, when the anode channel sealing performance deteriorates and when the electrolyte membrane cross-leak occurs, the same voltage may be displayed, so the leakage abnormality is based only on the change in the voltage of the fuel cell. Is difficult to determine.

  An object of the present invention is to provide a leakage abnormality determination method for a fuel cell system that can easily and reliably determine the occurrence of a leakage abnormality in each flow path when the fuel cell is stopped.

In order to solve the above-described problems, the present invention is configured such that fuel is supplied from a fuel supply source (for example, the hydrogen tank 30 in the embodiment) to the anode channel (for example, the anode channel 21 in the embodiment), and the cathode channel ( For example, a fuel cell (for example, the fuel cell 11 in the embodiment) that generates power by supplying air to the cathode channel 22 in the embodiment, and a first sealing unit (for example, the embodiment) that seals the anode channel. Shut-off valve 25 and purge valve 52), second sealing means for sealing the cathode flow path (for example, sealing valves 56 and 57 in the embodiment), and voltage detection for detecting the total voltage of the fuel cell. Means (for example, the voltage sensor 42 in the embodiment) and a timer (for example, the timer 46 in the embodiment) for measuring an elapsed time after the fuel cell power generation is stopped. In the fuel cell system (e.g., the fuel cell system 10 in the embodiment) including the control unit (e.g., the ECU 45 in the embodiment), the control unit is configured to stop the power generation of the fuel cell, and And the second sealing means while maintaining the flow path sealing of the fuel cell system, the elapsed time after power generation stop of the fuel cell is a first predetermined elapsed time (for example, the predetermined elapsed time TMSORKER in the embodiment). Alternatively, before the first predetermined elapsed time T1), the change width of the total voltage of the fuel cell with respect to the elapsed time after the stop of power generation of the fuel cell is the total voltage change width threshold (for example, the total voltage change width threshold Vfcva in the embodiment). ) May be determined as a leakage abnormality of the flow path seal of the fuel cell system.

When a considerable amount of time elapses after power generation of the fuel cell is stopped, the total voltage of the fuel cell starts to increase due to gas leaks in the anode flow path and the cathode flow path, and the pressure in each flow path changes from a decrease to an increase. A phenomenon occurs in which the oxygen concentration in the road rapidly increases. Even when each flow path seal is normal, the above-described phenomena occur after a predetermined elapsed time since the power generation of the fuel cell is stopped due to inevitable gas leakage. On the other hand, when the above-mentioned phenomena occur before the predetermined elapsed time, it can be determined that an excessive gas leak (leak abnormality) has occurred in each channel seal.
Therefore, the present invention provides at least one of the total voltage of the fuel cell, the pressure of the anode channel, the pressure of the cathode channel, the oxygen concentration of the anode channel, and the oxygen concentration of the cathode channel with respect to the elapsed time after the power generation of the fuel cell is stopped. From any one state change, it was set as the structure which determines the leakage abnormality of the flow-path sealing of a fuel cell system. Thereby, the fall of the sealing performance of each flow path including the fall of the sealing performance of the 1st sealing means and the 2nd sealing means can be detected collectively. Therefore, it is possible to easily and reliably determine the occurrence of leakage abnormality in each flow path.

When the total voltage of the fuel cell exceeds the total voltage change width threshold value, the change width of the total voltage of the fuel cell is large, it can be determined that the total voltage of the fuel cell is turned upward. If this phenomenon occurs before the first predetermined elapsed time, it can be determined that there is a leakage abnormality in the flow path sealing of the fuel cell system.

The present invention includes a fuel cell that is supplied with fuel from a fuel supply source to an anode flow path and is supplied with air to a cathode flow path to generate power, a first sealing means that seals the anode flow path, and the cathode flow path. A fuel cell comprising: a second sealing unit that seals a path; a voltage detection unit that detects a total voltage of the fuel cell; and a control unit that includes a timer that measures an elapsed time after power generation of the fuel cell is stopped. In the system, the control unit is configured to stop the power generation of the fuel cell and maintain the flow path sealing of the fuel cell system by the first sealing means and the second sealing means . Prior to the second predetermined elapsed time (for example, the predetermined elapsed time TMSORKER or the second predetermined elapsed time T2 in the embodiment) after the power generation stop, the pressure of the anode flow path and the pressure of the cathode flow path When at least one Chi is turned to the pressure increase from the pressure drop may be leakage abnormality and determines configuration of the channel seal of the fuel cell system.
If it is determined that a phenomenon in which at least one of the pressure of the anode flow path and the pressure of the cathode flow path changes from a pressure drop to a pressure rise occurs before the second predetermined elapsed time, the flow path of the fuel cell system It can be determined that there is a leakage abnormality in the seal.

The present invention includes a fuel cell that is supplied with fuel from a fuel supply source to an anode flow path and is supplied with air to a cathode flow path to generate power, a first sealing means that seals the anode flow path, and the cathode flow path. A fuel cell comprising: a second sealing unit that seals a path; a voltage detection unit that detects a total voltage of the fuel cell; and a control unit that includes a timer that measures an elapsed time after power generation of the fuel cell is stopped. In the system, the control unit is configured to stop the power generation of the fuel cell and maintain the flow path sealing of the fuel cell system by the first sealing means and the second sealing means . elapsed time after the power generation stop third predetermined elapsed time (e.g., a predetermined time elapsed TMSORKER or third predetermined elapsed time T3 in the embodiment) in front, with respect to an elapsed time after the power generation stop of the fuel cell, the anode At least one of the change width of the oxygen concentration of the cathode flow path and the change width of the oxygen concentration of the cathode flow path is an oxygen concentration change width threshold value (for example, the anode side oxygen concentration change width threshold value O2anva or the cathode side oxygen concentration change in the embodiment) A configuration may be adopted in which when the width threshold value O2cava) is exceeded, it is determined that the fuel cell system has a leakage of the channel sealing.
When at least one of the change width of the oxygen concentration in the anode flow path and the change width of the oxygen concentration in the cathode flow path exceeds the oxygen concentration change width threshold, the change width of the oxygen concentration is large. Can be judged to have soared. When this phenomenon occurs before the third predetermined elapsed time, it is determined that there is a leakage abnormality of each flow path seal.

The present invention includes a fuel cell that is supplied with fuel from a fuel supply source to an anode flow path and is supplied with air to a cathode flow path to generate power, a first sealing means that seals the anode flow path, and the cathode flow path. A fuel cell comprising: a second sealing unit that seals a path; a voltage detection unit that detects a total voltage of the fuel cell; and a control unit that includes a timer that measures an elapsed time after power generation of the fuel cell is stopped. In the system, the control unit is configured to stop the power generation of the fuel cell and maintain the flow path sealing of the fuel cell system by the first sealing means and the second sealing means . elapsed time after the power generation stop third predetermined elapsed time (e.g., a predetermined time elapsed TMSORKER or third predetermined elapsed time T3 in the embodiment) in front, with respect to an elapsed time after the power generation stop of the fuel cell, the anode When at least one of oxygen concentration and the oxygen concentration of the cathode channel of the de passage exceeds the oxygen concentration threshold may be leakage abnormality and determines configuration of the channel seal of the fuel cell system.
When at least one of the oxygen concentration in the anode flow channel and the oxygen concentration in the cathode flow channel exceeds the oxygen concentration threshold value, it can be determined that the oxygen concentration has rapidly increased because the absolute value of the oxygen concentration has increased. When this phenomenon occurs before the third predetermined elapsed time, it is determined that there is a leakage abnormality of each flow path seal.

The present invention includes a fuel cell that is supplied with fuel from a fuel supply source to an anode flow path and is supplied with air to a cathode flow path to generate power, a first sealing means that seals the anode flow path, and the cathode flow path. A fuel cell comprising: a second sealing unit that seals a path; a voltage detection unit that detects a total voltage of the fuel cell; and a control unit that includes a timer that measures an elapsed time after power generation of the fuel cell is stopped. In the system, the control unit maintains the flow path sealing of the fuel cell system by the first sealing means and the second sealing means while stopping the power generation of the fuel cell, (1) When an elapsed time after stopping the power generation of the fuel cell is a first predetermined elapsed time before a change width of the total voltage of the fuel cell with respect to an elapsed time after stopping the power generation of the fuel cell exceeds a total voltage change width threshold, (2) Power generation of the fuel cell When at least one of the pressure in the anode flow path and the pressure in the cathode flow path changes from a pressure decrease to a pressure increase before the second predetermined elapsed time after the stop, (3) Power generation of the fuel cell An elapsed time after the stop before a third predetermined elapsed time is at least one of a change width of the oxygen concentration of the anode flow path and a change width of the oxygen concentration of the cathode flow path with respect to the elapsed time after power generation stop of the fuel cell. When one exceeds the oxygen concentration change width threshold, (4) the anode flow path with respect to the elapsed time after the fuel cell power generation stop before the third predetermined elapsed time before the fuel cell power generation stop time When at least one of the oxygen concentration and the oxygen concentration in the cathode flow channel exceeds the oxygen concentration threshold, when two or more of the conditions (1) to (4) are satisfied, Charge may leak abnormality determining configuration of the channel seal of the battery system.
Thereby, it is possible to accurately determine the occurrence of leakage abnormality in each flow path seal.

The control unit may be configured to generate a warning signal when it is determined that there is an abnormality in leakage of the flow path seal of the fuel cell system.
As a result, it is possible to warn the user of the fuel cell system of the occurrence of a leakage abnormality and prompt repair.

The controller performs a fluid introduction / discharge process (for example, OCV purge process in the embodiment) on at least one of the anode flow path and the cathode flow path before connecting the load at the time of starting the fuel cell, and the fuel The fluid introduction / discharge at the next fuel cell start-up when the amount of processing of the fluid introduction / discharge process at the next fuel cell start-up when it is determined as a leakage abnormality of the channel seal of the battery system is not determined as a leak abnormality It is good also as a structure which sets more than the processing amount of a process.
The fuel cell system is provided with a fuel circulation means (for example, a hydrogen pump 26 in the embodiment) that circulates fuel from the outlet to the inlet of the anode flow path, and the controller operates the fuel circulation means. The amount of operation of the fuel circulation means at the next start-up of the fuel cell when the fluid introduction / discharge process is performed on the anode flow path and the flow path sealing of the fuel cell system is determined to be abnormal is determined as a leakage abnormality. It is good also as a structure which sets more than the operation amount of the said fuel circulation means at the time of the next fuel cell starting when it does not exist.
Thus, even when leakage abnormality occurs in each flow path seal, the oxygen gas remaining in the anode flow path can be surely replaced with hydrogen gas, and air / air activation can be avoided.

When the control unit determines that the fuel cell system has a channel sealing leak abnormality, the control unit releases the sealing of the anode channel by the first sealing unit and performs a scavenging process on the anode channel. It may be configured to execute.
As a result, moisture in the anode channel is removed, so that the replacement of the anode channel with hydrogen gas at the next start-up of the fuel cell can be suppressed from being inhibited by moisture. Therefore, the influence by the air / air activation can be reduced.

  According to the present invention, of the total voltage of the fuel cell, the pressure of the anode channel, the pressure of the cathode channel, the oxygen concentration of the anode channel, and the oxygen concentration of the cathode channel with respect to the elapsed time after the power generation of the fuel cell is stopped The configuration is such that the leakage abnormality of the flow path seal of the fuel cell system is determined from at least one of the state changes. Thereby, the fall of the sealing performance of each flow path including the fall of the sealing performance of the 1st sealing means and the 2nd sealing means can be detected collectively. Therefore, it is possible to easily and reliably determine the occurrence of leakage abnormality in each flow path.

It is a schematic block diagram of a fuel cell system. It is a graph which shows the relationship between the elapsed time after the power generation stop of a fuel cell, and the gas concentration of an anode flow path. It is a graph which shows the relationship between the elapsed time after the power generation stop of a fuel cell, and the pressure of an anode flow path. It is a graph which shows the relationship between the elapsed time after the power generation stop of a fuel cell, and the oxygen concentration of each flow path. It is a graph which shows the relationship between the elapsed time after the power generation stop of a fuel cell, and a total voltage. It is a typical graph which shows the relationship between the elapsed time after the power generation stop of a fuel cell, and the gas concentration of an anode flow path. It is a flowchart of the leakage abnormality determination method of the fuel cell system which concerns on this embodiment. It is a graph which shows the relationship between the stop temperature of a fuel cell system, and predetermined elapsed time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the case where the fuel cell system is mounted on a vehicle is taken as an example.

(Fuel cell system)
FIG. 1 is a schematic configuration diagram of a fuel cell system.
As shown in FIG. 1, the fuel cell 11 of the fuel cell system 10 is a solid polymer membrane fuel cell that generates electric power by an electrochemical reaction between an anode gas such as hydrogen gas and a cathode gas such as air. Specifically, a membrane electrode structure is formed by sandwiching a solid polymer electrolyte membrane between an anode electrode and a cathode electrode from both sides, and a pair of separators are arranged on both sides of the membrane electrode structure to form a flat unit cell. The fuel cell (stack) 11 is formed by stacking a plurality of the unit cells. In each unit cell, an anode channel 21 is formed between the anode electrode and the separator, and a cathode channel 22 is formed between the cathode electrode and the separator.

  An anode gas supply pipe 23 is connected to the inlet side of the anode flow path 21 of the fuel cell 11, and a hydrogen tank 30 is connected to the upstream end thereof. An anode off gas discharge pipe 35 is connected to the outlet side of the anode channel 21. On the other hand, a cathode gas supply pipe 24 is connected to the inlet side of the cathode flow path 22 of the fuel cell 11, and an air pump 33 is connected to the upstream end thereof. A cathode offgas discharge pipe 38 is connected to the outlet side of the cathode channel 22. In the present embodiment, the anode flow path 21, the anode gas supply pipe 23, and the anode off gas discharge pipe 35 constitute the anode gas flow passage 61, and the cathode flow path 22, the cathode gas supply pipe 24, and the cathode off gas discharge pipe 38 are formed. A cathode gas flow passage 62 is formed.

  Hydrogen gas (anode gas) flows from the hydrogen tank 30 through the anode gas supply pipe 23, is decompressed by a regulator (not shown), and is then supplied to the anode flow path 21 of the fuel cell 11. Further, an electromagnetically driven shut-off valve 25 is provided in the vicinity of the hydrogen tank 30 in the anode gas supply pipe 23. The shutoff valve 25 can switch between supply and shutoff of hydrogen gas from the hydrogen tank 30.

  After the hydrogen gas is used for power generation, it is discharged from the fuel cell 11 to the anode off-gas discharge pipe 35 as the anode off-gas. The anode off gas discharge pipe 35 is provided with a catch tank 53 as a gas-liquid separator. The anode off gas discharge pipe 35 is connected to the anode gas supply pipe 23 through the hydrogen pump 26. The hydrogen pump 26 functions as a fuel circulation means, and the anode off-gas discharged through the fuel cell 11 can be reused as the anode gas of the fuel cell 11. An ejector (not shown) may be disposed at the connection portion of the anode off gas discharge pipe 35 to the anode gas supply pipe 23. Further, a purge gas discharge pipe 37 is branched from the anode off gas discharge pipe 35 and connected to the dilution box 31. The purge gas discharge pipe 37 is provided with an electromagnetically driven purge valve 52. The purge valve 52 and the shut-off valve 25 described above function as a sealing valve that seals the anode gas in the anode flow path 21.

  After passing through the air flow sensor 32, the air (cathode gas) is pressurized by the air pump 33, flows through the cathode gas supply pipe 24, and is supplied to the cathode flow path 22 of the fuel cell 11. After this oxygen in the air is used as an oxidizing agent for power generation, it is discharged from the fuel cell 11 to the cathode offgas discharge pipe 38 as cathode offgas. The cathode offgas discharge pipe 38 is connected to the dilution box 31. In the dilution box 31, the anode off gas is diluted with the cathode off gas and exhausted to the outside. The cathode offgas discharge pipe 38 is provided with a back pressure valve (not shown). A humidifier 39 is bridged between the cathode gas supply pipe 24 and the cathode off gas discharge pipe 38. The moisture contained in the cathode off-gas moves to the cathode gas in the humidifier 39 so that the cathode gas is humidified. Furthermore, the cathode gas supply pipe 24 and the cathode off gas discharge pipe 38 are provided with electromagnetically driven sealing valves 56 and 57, respectively, so that the cathode gas can be sealed in the cathode flow path 22. It is configured.

  One end of a scavenging gas introduction pipe 54 is connected to the cathode gas supply pipe 24 that connects the air pump 33 and the fuel cell 11. The other end of the scavenging gas introduction pipe 54 is connected to the anode gas supply pipe 23. That is, as the scavenging gas, the air pressurized by the air pump 33 can be supplied to the anode flow path 21 of the fuel cell 11. The scavenging gas introduction pipe 54 is provided with an electromagnetic valve 55 so that the supply of air from the air pump 33 to the anode channel 21 can be shut off.

  The anode gas supply pipe 23 is provided with a pressure sensor 41 a that can detect the anode gas pressure in the anode flow path 21. The cathode gas supply pipe 24 is provided with a pressure sensor 41 c that measures the cathode gas pressure in the cathode channel 22. Further, the fuel cell 11 is provided with a voltage sensor 42 for measuring the total voltage. In addition, the anode gas supply pipe 23 is provided with an oxygen concentration sensor 43 a that measures the oxygen concentration in the anode flow path 21. The cathode gas supply pipe 24 is provided with an oxygen concentration sensor 43 c that measures the oxygen concentration in the cathode flow path 22. As an oxygen concentration sensor, in addition to a zirconia oxygen concentration meter, an electrode oxygen concentration meter can be employed.

  The ECU 45 controls the operation of each component of the fuel cell system 10. Specifically, the ECU 45 controls the start and stop of the fuel cell system based on the ON / OFF signal from the ignition switch. Further, the ECU 45 controls the air pump 33 and the shutoff valve 25 according to the required output to the fuel cell 11 and supplies a predetermined amount of air and hydrogen gas to the fuel cell 11 to generate power.

  The ECU 45 performs an anode scavenging process for the purpose of removing moisture in the anode channel 21 while the fuel cell system is stopped. Specifically, the solenoid valve 55 and the purge valve 52 are opened to release the sealing of the anode flow path, and then the air pump 33 is driven, and the cathode gas supply pipe 24, the scavenging gas introduction pipe 54, and the anode gas supply pipe 23 are driven. Air is introduced into the anode channel 21 via the. Moisture in the anode flow path 21 is discharged to the outside through the anode off-gas discharge pipe 35 and the purge gas discharge pipe 37 together with the introduced air.

  The ECU 45 performs OCV purge (fluid introduction / discharge processing) for the purpose of early stabilization of power generation and the like when the fuel cell system is started. Specifically, first, the shut-off valve 25 is opened to introduce hydrogen gas into the anode flow path 21. When the purge valve 52 is opened when the pressure in the anode passage 21 rises, the residual gas in the anode passage 21 is discharged through the anode off-gas discharge pipe 35 and the purge gas discharge pipe 37. Thereby, the residual gas in the anode channel 21 is replaced with hydrogen gas. If the hydrogen pump 26 is driven, the replacement with hydrogen gas is promoted.

  The measurement results (sensor outputs) of the pressure sensors 41a and 41c, the voltage sensor 42, and the oxygen concentration sensors 43a and 43c described above are input to an ECU (control unit) 45. The ECU 45 has a timer 46 that measures an elapsed time after stopping the power generation of the fuel cell. The ECU 45 determines the leakage abnormality of the flow path seal of the fuel cell system 10 based on the elapsed time after stopping the power generation of the fuel cell and the measurement result of each sensor. The method for determining leakage abnormality will be described in detail later. The ECU 45 is connected to alarm means 47 for notifying a passenger of the vehicle of a leakage abnormality. When the ECU 45 determines that there is a leakage abnormality, the ECU 45 outputs a warning signal to the alarm means 47 to notify the leakage abnormality.

(Judgment principle of leakage abnormality)
The fuel cell system leakage abnormality determination method according to the present embodiment is based on the following knowledge.
When power generation of the fuel cell is stopped, the ECU 45 performs the following control based on the OFF signal of the ignition switch. That is, the air pump 33 is stopped to stop the supply of air, and the shutoff valve 25 is closed to stop the supply of hydrogen gas. Further, the anode side sealing valves (the shut-off valve 25 and the purge valve 52) are closed to seal hydrogen gas in the anode flow path 21, and the cathode side sealing valves 56 and 57 are closed to close the cathode. Air is sealed in the flow path 22. At this time, in order to suppress deterioration of the fuel cell, sealing is performed so that the molar ratio of hydrogen gas to oxygen gas in the air is 2 or more (hydrogen gas is excessive).

  FIG. 2 is a graph showing the relationship between the elapsed time after stopping the power generation of the fuel cell and the gas concentration in the anode channel. Immediately after stopping the power generation of the fuel cell, the anode channel 21 is in a hydrogen-rich state where the hydrogen concentration is greater than the oxygen concentration, and the cathode channel 22 filled with air is in an oxygen-rich state where the oxygen concentration is greater than the hydrogen concentration. . These hydrogen gas and oxygen gas are consumed by an electrochemical reaction through the electrolyte membrane. However, since the hydrogen gas is excessively sealed, the hydrogen gas remains in the anode channel 21. Thereafter, a part of the hydrogen gas permeates the electrolyte membrane and moves to the cathode channel 22, so that the hydrogen concentration in the anode channel 21 decreases as shown in FIG. 2. As time elapses after the power generation of the fuel cell is stopped, air flows into the anode channel 21 due to slight leakage of the anode-side sealing valves 25 and 52. Then, the oxygen gas in the air that has flowed in reacts with the hydrogen gas remaining in the anode channel 21 to consume the hydrogen gas, so that the hydrogen concentration in the anode channel 21 further decreases. Note that nitrogen gas or the like remains in the anode channel 21 after the reaction.

FIG. 3 is a graph showing the relationship between the elapsed time after stopping the power generation of the fuel cell and the pressure in the anode flow path. Since the hydrogen concentration in the anode channel 21 decreases with the lapse of time after the power generation of the fuel cell is stopped, the pressure in the anode channel 21 decreases.
The pressure in the cathode channel 22 also changes in the same manner as in the graph of FIG. As described above, after the power generation of the fuel cell is stopped, a part of the hydrogen gas in the anode channel 21 passes through the electrolyte membrane and moves to the cathode channel 22. As the fuel cell stop time elapses, air flows into the cathode channel 22 due to slight leakage of the cathode-side sealing valves 56 and 57. Since oxygen in the air that has flowed in and hydrogen gas present in the cathode channel 22 react and are consumed, the pressure in the cathode channel 22 decreases as in the graph of FIG.

Here, when the hydrogen gas in the cathode channel 22 is consumed and reduced, oxygen gas that has flowed into the cathode channel 22 thereafter remains in the cathode channel 22 without being consumed. For this reason, after the second predetermined elapsed time T2, the pressure in the cathode channel 22 starts to increase from the decrease (phenomenon 2C).
FIG. 4 is a graph showing the relationship between the elapsed time after stopping the power generation of the fuel cell and the oxygen concentration in each channel. After the third predetermined elapsed time T3, oxygen remains in the cathode channel 22, so that the oxygen concentration rapidly increases (phenomenon 3C).

  FIG. 5 is a graph showing the relationship between the elapsed time after stopping the power generation of the fuel cell and the total voltage. Before the first predetermined elapsed time T1, both the anode channel 21 and the cathode channel 22 are in a hydrogen-rich state, so the total voltage of the fuel cell is 0V. On the other hand, after the first predetermined elapsed time T1, the cathode channel 22 is in an oxygen-rich state. Even in this case, since hydrogen gas remains in the anode channel 21, the hydrogen gas in the anode channel 21 and the oxygen gas in the cathode channel 22 react via the electrolyte membrane. Therefore, the total voltage of the fuel cell starts to increase after the first predetermined elapsed time T1 (Phenomenon 1).

  Thus, since the hydrogen gas in the anode flow path 21 reacts with the oxygen gas in the cathode flow path 22, the oxygen gas flowing into the anode flow path 21 from the anode side sealing valves 25 and 52 reacts with the hydrogen gas. Without remaining in the anode flow path 21. Therefore, as shown in FIG. 3, after the second predetermined elapsed time T2, the pressure of the anode channel 21 starts to increase from the decrease (phenomenon 2A). Further, as shown in FIG. 4, after the third predetermined elapsed time T3, the oxygen concentration in the anode channel 21 rapidly increases (phenomenon 3A).

Returning to FIG. 2, after the predetermined elapsed time TMSO A KER, the hydrogen gas is reduced and the oxygen gas is increased in the anode flow path 21. Thereby, oxygen gas increases in both the anode channel 21 and the cathode channel 22. Therefore, the next start-up of the fuel cell after the lapse of a predetermined time is started (air / air start-up) in a state where air is abundant (oxygen-rich) in both poles as the first gas state.

The phenomena 1 to 3 described above occur when air flows into the anode channel 21 and the cathode channel 22 due to a slight leak of the sealing valve. Even in the case of a sealing valve with normal sealing performance, there are inevitably slight leaks, so the above phenomena 1 to 3 occur. When the sealing performance of the sealing valve on the anode side and the cathode side is normal, the first predetermined elapsed time T1 in FIG. 5, the second predetermined elapsed time T2 in FIG. 3, and the third predetermined elapsed time T3 in FIG. Almost the same value (predetermined elapsed time TMSO A KER). Since the oxygen concentration is considered to rise significantly after the hydrogen gas in the anode channel 21 is completely exhausted, the third predetermined elapsed time T3 is longer than the first predetermined elapsed time T1 and the second predetermined elapsed time T2. In some cases.
On the other hand, when there is an imbalance in the sealing performance of the sealing valve on the anode side and the cathode side, each predetermined elapsed time becomes a different value. For example, when the anode-side sealing performance is significantly reduced, the hydrogen gas in the anode channel 21 flows out, so that the total voltage does not increase (Phenomenon 1), and the pressure in each channel (Phenomenon 2) and A rapid increase in oxygen concentration (phenomenon 3) occurs first. In this case, the first predetermined elapsed time T1 is longer than the second predetermined elapsed time T2 and the third predetermined elapsed time T3.

FIG. 6 is a schematic graph showing the relationship between the elapsed time after stopping the power generation of the fuel cell and the gas concentration in the anode flow path, and FIG. 6A shows the case where the sealing performance of the sealing valve is normal. FIG. 6B shows the case where the sealing performance of the sealing valve is lowered. FIG. 6 (a) schematically shows the graph of FIG.
As shown in FIG. 6 (a), the anode channel 21 in which the elapsed time (soak time) after the power generation stop of the fuel cell is before the predetermined elapsed time TMSO A KER is in a hydrogen-rich state, but the predetermined elapsed time TMSO. The anode flow path 21 after A KER is in an oxygen-rich state, and air / air activation is performed. The predetermined elapsed time TMSO A KER can be said to be a sealing effective period in which sealing can be performed so that air / air activation is not caused by a sealing valve having normal sealing performance.

As shown in FIG. 6B, when the sealing performance of the sealing valve is reduced and the leak becomes large, a large amount of air flows into the anode flow path 21, and oxygen gas in the air reacts with hydrogen gas. As a result, the hydrogen concentration rapidly decreases. In addition, since oxygen gas tends to remain in the anode channel 21, the oxygen concentration rapidly increases. Therefore, the time during which the anode flow path 21 is rich in oxygen is shorter than the predetermined elapsed time TMSO A KER in FIG. In this case, the number of times of air / air activation increases, and the deterioration of the fuel cell is promoted. Therefore, when the above-described phenomena 1 to 3 occur in the soak time TMSO A K before the predetermined elapsed time TMSO A KER, it is determined that the sealing performance of the sealing valve has deteriorated (there is a leakage abnormality). be able to.

(Fuel cell system leakage abnormality judgment method)
FIG. 7 is a flowchart of a leakage abnormality determination method for the fuel cell system according to this embodiment. First, the operation of the fuel cell system is stopped (S10). Specifically, the ECU 45 performs the following control based on the OFF signal of the ignition switch. That is, the air pump 33 is stopped to stop the supply of air, and the shutoff valve 25 is closed to stop the supply of hydrogen gas. Further, the anode side sealing valves (the shut-off valve 25 and the purge valve 52) are closed to seal hydrogen gas in the anode flow path 21, and the cathode side sealing valves 56 and 57 are closed to close the cathode. Air is sealed in the flow path 22. Then, the timer 46 of the ECU 45 is operated.

Then, the elapsed time after the power generation stop of the fuel cell (soak time) TMSO A K measures the (S12). The soak time is measured by reading the elapsed time of the timer 46 periodically every predetermined time after the fuel cell stops generating power.
Next, the state quantity of the fuel cell is measured by each sensor (S14). Specifically, the pressure Pan in the anode channel 21 is measured by the pressure sensor 41a, and the pressure Pca in the cathode channel 22 is measured by the pressure sensor 41c. Further, the voltage sensor 42 measures the total voltage Vfc of the fuel cell 11. Further, the oxygen concentration sensor 43a measures the oxygen concentration O2an in the anode channel 21, and the oxygen concentration sensor 43c measures the oxygen concentration O2ca in the cathode channel 22.

Next, the change width (change rate) of the state quantity of the fuel cell is calculated (S16). Specifically, the difference between the state quantity measured this time and the state quantity measured last time is calculated by the following equations.
dPan = Pan -Pan1
dPca = Pca -Pca1
dVfc = Vfc−Vfc1
dO2an = O2an-O2an1
dO2ca = O2ca-O2ca1
The left side of each expression is the change amount of the state quantity, the first term on the right side is the state quantity measured this time, and the second term on the right side is the state quantity measured last time.

Next, it is determined by the following formulas whether the change width of the state quantity is larger than the change width threshold or whether the state quantity itself is larger than the threshold (S18).
dPan> Panva (1)
dPca> Pcava (2)
dVfc> Vfcva (3)
dO2an> O2anva (4)
dO2ca> O2cava (5)
O2an> O2an2 (6)
O2ca> O2ca2 (7)
The right side of Equations (1) to (5) is a state amount change width threshold, and the right side of Equations (6) and (7) is the threshold of oxygen concentration itself. Each change width threshold and each threshold are obtained in advance by experiments or the like so that the occurrence of the above-described phenomena 1 to 3 can be determined.

The determination in S18 may be made on the condition that any one of (1) to (7) is satisfied, or may be made on the condition that a plurality of expressions are satisfied. When the establishment of a plurality of conditions is a condition, it is possible to accurately determine the occurrence of a leakage abnormality in each flow path seal.
If the determination in S18 is No, it can be determined that the above-described phenomena 1 to 3 have not occurred. In this case, the process proceeds to S20, where the state quantity measured last time is replaced with the state quantity measured this time, and S12 and subsequent steps are repeated.

On the other hand, when the determination in S18 is Yes, it can be determined that the above-described phenomena 1 to 3 have occurred.
However, even if the flow path sealing is normal, phenomena 1 to 3 inevitably occur after a predetermined elapsed time, so it cannot be immediately determined that there is a leakage abnormality. Accordingly, the process proceeds to S22, in which it is determined whether the current soak time TMSO A K is shorter than a predetermined elapsed time TMSO A KER of a sealing valve having a normal sealing performance. As described with reference to FIG. 6B, when the phenomena 1 to 3 occur before the predetermined elapsed time TMSO A KER, it can be determined that there is a leakage abnormality of the sealing valve. Therefore, if the determination in S22 is Yes, the process proceeds to S24, and it is determined that there is a leakage abnormality (leak failure) in each flow path seal.

That is, when the expression (1) is established in S18 (when the change width of the pressure in the anode flow path exceeds the anode side pressure change width threshold value), the change width of the anode gas pressure Pan is large. As shown in FIG. 3, it can be determined that the anode gas pressure has changed from a decrease to an increase (phenomenon 2A has occurred). If it is determined in S22 that this phenomenon 2A has occurred before the second predetermined elapsed time T2, it is determined in S24 that there is a leakage abnormality in each flow path seal.
Further, when the expression (2) is established in S18 (when the change width of the cathode flow path pressure exceeds the cathode side pressure change width threshold value), the change width of the cathode gas pressure Pca is large. As in FIG. 3, it can be determined that the cathode gas pressure has changed from a decrease to an increase (phenomenon 2C has occurred). In S22, when this phenomenon 2C occurs before the second predetermined elapsed time T2, it is determined in S24 that there is a leakage abnormality in each flow path seal.

  On the other hand, when the expression (3) is satisfied in S18 (when the change width of the total voltage of the fuel cell exceeds the total voltage change width threshold value), the change width of the total voltage of the fuel cell is large. As shown in FIG. 5, it can be determined that the total voltage of the fuel cell has started to increase (phenomenon 1 has occurred). In S22, when this phenomenon 1 occurs before the first predetermined elapsed time T1, it is determined in S24 that there is a leakage abnormality of each flow path seal.

On the other hand, when the expression (4) is established in S18 (when the change width of the oxygen concentration in the anode flow path exceeds the anode-side oxygen concentration change width threshold value), the change width of the oxygen concentration O2an in the anode flow path 21 is Since it is increased, it can be determined that the oxygen concentration in the anode channel 21 has rapidly increased (phenomenon 3A has occurred) as shown in FIG. In S22, when this phenomenon 3A occurs before the third predetermined elapsed time T3, it is determined in S24 that there is a leakage abnormality of each flow path seal.
Further, when the expression (5) is established in S18 (when the change width of the oxygen concentration in the cathode flow path exceeds the cathode side oxygen concentration change width threshold value), the change width of the oxygen concentration O2ca in the cathode flow path 22 is Since it is increased, it can be determined that the oxygen concentration in the cathode channel 22 has rapidly increased (phenomenon 3C has occurred) as shown in FIG. In S22, when this phenomenon 3C occurs before the third predetermined elapsed time T3, it is determined in S24 that there is a leakage abnormality of each flow path seal.

On the other hand, when the expression (6) is established in S18 (when the oxygen concentration in the anode channel exceeds the anode oxygen concentration threshold), the absolute value of the oxygen concentration O2an in the anode channel 21 is large. 4, it can be determined that the oxygen concentration in the anode flow path 21 has rapidly increased (phenomenon 3A has occurred). In S22, when this phenomenon 3A occurs before the third predetermined elapsed time T3, it is determined in S24 that there is a leakage abnormality of each flow path seal.
In addition, when the expression (7) is established in S18 (when the oxygen concentration in the cathode channel exceeds the cathode-side oxygen concentration threshold), the absolute value of the oxygen concentration O2ca in the cathode channel 22 is large. 4, it can be determined that the oxygen concentration in the cathode flow path 22 has rapidly increased (phenomenon 3C has occurred). In S22, when this phenomenon 3C occurs before the third predetermined elapsed time T3, it is determined in S24 that there is a leakage abnormality of each flow path seal.

FIG. 8 is a graph showing the relationship between the stop temperature of the fuel cell system and the predetermined elapsed time. The predetermined elapsed time TMSO A KER is a time until the phenomena 1 to 3 occur when the sealing performance of the sealing valve is normal, and is a constant value. However, as the temperature of the fuel cell increases, the gas permeability of each part of the seal increases, so the sealing performance decreases. In this case, as described with reference to FIG. 6B, the time until the phenomena 1 to 3 occur is shortened. In the graph of FIG. 8, the higher the stop temperature of the fuel cell system, the higher the temperature of the fuel cell in the soak, so the predetermined elapsed time TMSO A KER is shorter. Therefore, if the predetermined elapsed time TMSO A KER calculated from the graph of FIG. 8 is used, it is possible to accurately determine the leakage abnormality. In addition, as the stop temperature of the fuel cell system, the refrigerant temperature at the time of stopping the power generation of the fuel cell can be used.

  If it is determined in S24 that there is a leakage abnormality (leak failure), a warning signal is output to the alarm means 47 to notify the leakage abnormality, and an OCV purge (fluid introduction / discharge process) at the next startup of the fuel cell is performed. The processing amount is set to be larger than the processing amount of the OCV purge when it is not determined that there is a leakage abnormality. Specifically, the shutoff valve 25 is opened, the opening time of the purge valve 52 is extended, the amount of hydrogen gas supplied to the anode passage 21 is increased, and the oxygen gas remaining in the anode passage 21 is increased. Make sure to replace with hydrogen gas. Further, the amount of operation such as the number of revolutions and operation time of the hydrogen pump 26 is increased to promote replacement with hydrogen gas. Thereby, even when a leakage abnormality occurs in the fuel cell system, the oxygen gas remaining in the anode flow path 21 can be reliably replaced with hydrogen gas, and air / air activation can be avoided, thereby preventing deterioration of the fuel cell. be able to.

When it is determined in S24 that there is a leakage abnormality (leak failure), it is desirable to perform anode scavenging during the soak. Since the water in the anode flow path 21 is removed by the scavenging of the anode, it is possible to prevent the replacement of the anode flow path 21 with hydrogen gas from being inhibited by the water at the next start-up of the fuel cell. Thereby, since the influence by air / air starting can be reduced, deterioration of the fuel cell can be prevented.
Thus, the leakage abnormality determination process for the fuel cell system according to this embodiment is completed.

  As described above in detail, the leakage abnormality determination method for the fuel cell system 10 according to the present embodiment includes the anode-side sealing valves 25 and 52 and the cathode-side sealing valves 56 and 57 as well as the power generation stop of the fuel cell 11. In the state where the flow path sealing of the fuel cell system 10 is maintained, the total voltage of the fuel cell 11, the pressure of the anode flow path 21, the pressure of the cathode flow path 22, the anode flow path with respect to the elapsed time after the stop of the fuel cell 11 From the change in the state of at least one of the oxygen concentration of 21 and the oxygen concentration of the cathode flow path 22, the flow path sealing leakage abnormality of the fuel cell system 10 is determined.

  When a considerable time elapses after the power generation of the fuel cell is stopped, the total voltage of the fuel cell 11 starts to increase due to the gas leak in the anode channel 21 and the cathode channel 22, and the pressure in each channel 21, 22 decreases. A phenomenon occurs in which the oxygen concentration in each of the flow paths 21 and 22 suddenly increases. Even when each flow path seal is normal, the above-described phenomena occur after a predetermined elapsed time since the power generation of the fuel cell is stopped due to inevitable gas leakage. On the other hand, when the above-mentioned phenomena occur before the predetermined elapsed time, it can be determined that an excessive gas leak (leak abnormality) has occurred in each channel seal.

  Therefore, in this embodiment, the total voltage of the fuel cell 11, the pressure of the anode channel 21, the pressure of the cathode channel 22, the oxygen concentration of the anode channel 21, and the cathode channel with respect to the elapsed time after the power generation of the fuel cell 11 is stopped. The configuration is such that the leakage abnormality of the flow path seal of the fuel cell system 10 is determined from at least one of the 22 oxygen concentrations. Thereby, the fall of the sealing performance of each flow path including the fall of the sealing performance of each sealing valve can be detected collectively. Therefore, it is possible to easily and reliably determine the occurrence of leakage abnormality in each flow path. Along with this, it is possible to take measures to avoid the next start of the fuel cell being air / air start, so that deterioration of the fuel cell can be suppressed.

It should be noted that the technical scope of the present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention. That is, the configuration of the above-described embodiment is merely an example, and can be changed as appropriate.
For example, the configuration of the fuel cell system 10 is not limited to the configuration of the embodiment, and may be other configurations.
In the embodiment, the shut-off valve 25 and the purge valve 52 function as the anode-side sealing valve. However, valves other than the shut-off valve 25 and the purge valve 52 may function as the sealing valve, and the same as the cathode side. A dedicated sealing valve may be provided.

In the embodiment, when the above-described phenomena 1 to 3 occur in the soak time TMSO A K before the predetermined elapsed time TMSO A KER, it is determined that there is an abnormality in leakage of the channel seal. On the other hand, without using the predetermined elapsed time TMSO A KER uniformly, the first predetermined elapsed time T1 is used for phenomenon 1, the second predetermined elapsed time T2 is used for phenomenon 2, and the phenomenon 3 is used. May be determined using the third predetermined elapsed time T3.

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 11 ... Fuel cell 21 ... Anode flow path 22 ... Cathode flow path 25 ... Shut-off valve (first sealing means) 26 ... Hydrogen pump (fuel circulation means) 30 ... Hydrogen tank (fuel supply source) 42 ... Voltage sensor (voltage detection means) 45 ... ECU (control unit) 46 ... Timer 47 ... Alarm means 52 ... Purge valve (first sealing means) 56 ... Sealing valve (second sealing means) 57 ... Sealing valve ( Second sealing means)

Claims (9)

A fuel cell that is supplied with fuel from the fuel supply source to the anode flow path and is supplied with air to the cathode flow path;
First sealing means for sealing the anode flow path;
A second sealing means for sealing the cathode channel;
Voltage detecting means for detecting the total voltage of the fuel cell;
A control unit having a timer for measuring an elapsed time after stopping the power generation of the fuel cell;
In a fuel cell system comprising:
The controller is
With the power generation stop of the fuel cell, while maintaining the flow path sealing of the fuel cell system by the first sealing means and the second sealing means,
When the change width of the total voltage of the fuel cell with respect to the elapsed time after the stoppage of power generation of the fuel cell exceeds the total voltage change width threshold before the first predetermined elapsed time before the stoppage of power generation of the fuel cell In addition, it is determined that the fuel cell system has a flow path sealing leak abnormality.
A leakage abnormality determination method for a fuel cell system. A fuel cell that is supplied with fuel from the fuel supply source to the anode flow path and is supplied with air to the cathode flow path;
First sealing means for sealing the anode flow path;
A second sealing means for sealing the cathode channel;
Voltage detecting means for detecting the total voltage of the fuel cell;
A control unit having a timer for measuring an elapsed time after stopping the power generation of the fuel cell;
In a fuel cell system comprising:
The controller is
With the power generation stop of the fuel cell, while maintaining the flow path sealing of the fuel cell system by the first sealing means and the second sealing means,
When the fuel cell has stopped generating power before the second predetermined elapsed time, when at least one of the pressure in the anode flow path and the pressure in the cathode flow path has changed from a pressure drop to a pressure rise, It is determined that there is a leakage abnormality in the battery system flow path seal.
A leakage abnormality determination method for a fuel cell system. A fuel cell that is supplied with fuel from the fuel supply source to the anode flow path and is supplied with air to the cathode flow path;
First sealing means for sealing the anode flow path;
A second sealing means for sealing the cathode channel;
Voltage detecting means for detecting the total voltage of the fuel cell;
A control unit having a timer for measuring an elapsed time after stopping the power generation of the fuel cell;
In a fuel cell system comprising:
The controller is
With the power generation stop of the fuel cell, while maintaining the flow path sealing of the fuel cell system by the first sealing means and the second sealing means,
The elapsed time after stopping the power generation of the fuel cell before the third predetermined elapsed time, the change width of the oxygen concentration in the anode channel and the oxygen concentration in the cathode channel with respect to the elapsed time after stopping the power generation of the fuel cell. When at least one of the change widths exceeds an oxygen concentration change width threshold value, it is determined that the fuel cell system has a leakage of the channel seal.
A leakage abnormality determination method for a fuel cell system. A fuel cell that is supplied with fuel from the fuel supply source to the anode flow path and is supplied with air to the cathode flow path;
First sealing means for sealing the anode flow path;
A second sealing means for sealing the cathode channel;
Voltage detecting means for detecting the total voltage of the fuel cell;
A control unit having a timer for measuring an elapsed time after stopping the power generation of the fuel cell;
In a fuel cell system comprising:
The controller is
With the power generation stop of the fuel cell, while maintaining the flow path sealing of the fuel cell system by the first sealing means and the second sealing means,
At least one of the oxygen concentration in the anode flow channel and the oxygen concentration in the cathode flow channel with respect to the elapsed time after the power generation stop of the fuel cell before the third predetermined elapsed time before the power generation stop time of the fuel cell When the oxygen concentration threshold is exceeded, it is determined that the fuel cell system has a leakage of the channel seal.
A leakage abnormality determination method for a fuel cell system. A fuel cell that is supplied with fuel from the fuel supply source to the anode flow path and is supplied with air to the cathode flow path;
First sealing means for sealing the anode flow path;
A second sealing means for sealing the cathode channel;
Voltage detecting means for detecting the total voltage of the fuel cell;
A control unit having a timer for measuring an elapsed time after stopping the power generation of the fuel cell;
In a fuel cell system comprising:
The controller is
With the power generation stop of the fuel cell, while maintaining the flow path sealing of the fuel cell system by the first sealing means and the second sealing means,
(1) An elapsed time after stopping the power generation of the fuel cell is before a first predetermined elapsed time, and a change width of the total voltage of the fuel cell with respect to an elapsed time after stopping the power generation of the fuel cell is set to a total voltage change width threshold value. When exceeded
(2) When at least one of the pressure in the anode flow path and the pressure in the cathode flow path changes from a pressure drop to a pressure rise before the second predetermined elapsed time before the fuel cell power generation stoppage,
(3) The change in oxygen concentration in the anode flow path and the change in the cathode flow path relative to the elapsed time after the fuel cell power generation stop before the third predetermined elapsed time before the fuel cell power generation stop. When at least one of the oxygen concentration change widths exceeds the oxygen concentration change width threshold,
(4) The oxygen concentration in the anode flow channel and the oxygen concentration in the cathode flow channel with respect to the elapsed time after the fuel cell power generation is stopped before the third predetermined elapsed time before the fuel cell power generation is stopped. When at least one of them exceeds the oxygen concentration threshold,
When two or more of the conditions (1) to (4) are satisfied, it is determined that the fuel cell system has a leakage of the channel seal.
A leakage abnormality determination method for a fuel cell system. The controller is
A warning signal is generated when it is determined that the fuel cell system has a leakage of the channel seal.
Leakage abnormality determination method of a fuel cell system according to any one of claims 1 to 5, characterized in that. The controller is
Before connecting the load at the time of starting the fuel cell, perform a fluid introduction / discharge process for at least one of the anode flow path and the cathode flow path,
The fluid at the next start of the fuel cell when the amount of processing of the fluid introduction / discharge process at the next start of the fuel cell when it is determined as a leakage abnormality of the flow path seal of the fuel cell system is not determined as a leak abnormality Set more than the amount of introduction discharge processing,
The fuel cell system leakage abnormality determination method according to any one of claims 1 to 6 , characterized in that: The fuel cell system is provided with fuel circulation means for circulating fuel from the outlet to the inlet of the anode flow path,
The controller is
The fluid circulation means is operated to perform the fluid introduction / discharge process with respect to the anode flow path,
The fuel circulation at the next start of the fuel cell when the operation amount of the fuel circulation means at the next start of the fuel cell when it is determined as a leakage abnormality of the flow path seal of the fuel cell system is not determined as a leak abnormality Set more than the amount of movement of the means,
The fuel cell system leakage abnormality determination method according to claim 7 . The controller is
When it is determined that the fuel cell system has a channel sealing leakage abnormality, the anode channel sealing by the first sealing unit is released, and a scavenging process is performed on the anode channel.
The fuel cell system leakage abnormality determination method according to any one of claims 1 to 6 , characterized in that:

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