JP2006032098A - Failure diagnostic apparatus for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure diagnostic apparatus for fuel cells capable of balancing a failure detection capability and the avoidance of an erroneous diagnosis. <P>SOLUTION: The failure diagnostic apparatus for fuel cells comprises a voltage detection means 15 that detects a battery voltage with respect to each unit cell 1 or each battery pack connected in series with a plurality of unit cells 1, a fuel gas flow rate adjusting means 12 that adjusts a flow rate of a reactant gas which is energized to a fuel cell 10, and an oxidant gas flow rate adjusting means 14. A judging value setting means (S8) sets a detection threshold of a voltage variation caused when changing a flow rate of a reactant gas from a predetermined value Q<SB>1</SB>to Q<SB>2</SB>in response to a temperature detection means 16 as a judging value Cj<SB>a</SB>. Further a diagnosis means (S9) performs a failure diagnosis by comparing a detection value ΔV<SB>a</SB>of a voltage variation caused when changing a flow rate of a reactant gas with the judging values Cj<SB>a</SB>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell failure diagnosis apparatus. In particular, the present invention relates to a failure diagnosis apparatus for diagnosing whether or not a reactant gas leaks in a fuel cell including a solid polymer electrolyte membrane and configured by stacking a plurality of unit cells.

  In order for the fuel cell to generate electric power, it is necessary that the reaction gas is sufficiently supplied to the fuel electrode and the oxidant electrode. However, when a defect occurs in the electrolyte membrane and the fuel gas leaks to the oxidant electrode, or conversely, the oxidant gas leaks to the fuel electrode, the fuel gas and the oxidant gas are directly reacted and consumed. As a result, the reaction gas is insufficient, and heat of reaction is generated in the reaction portion, which raises the temperature of the electrode catalyst layer and the electrolyte membrane. This is a concern because it greatly affects the reliability of the fuel cell. When such a reaction gas leakage occurs, it is important to quickly detect the failure and take necessary measures as a system.

  As a method for detecting such a defect, the fuel gas is supplied to the fuel electrode, the oxygen-containing gas is supplied to the oxidant electrode, and the battery voltage changes rapidly due to the change in the supply amount of the oxidant-containing gas. It is known that an electrolyte deficiency has occurred (see, for example, Patent Document 1).

Alternatively, in the state where the flow rate of the oxygen-containing gas is less than the reference value for quality determination that is less than the set value in normal operation, the flow state of the fuel gas is changed, and the electrolyte loss is detected using the change in the open circuit voltage as the determination information Those are known (for example, see Patent Document 2).
Japanese Patent Laid-Open No. 9-27336 JP-A-11-67255

  In the above-described conventional technology, the reaction gas flow rate or the like is changed, and the leakage of the reaction gas is detected using the change in the battery voltage that can be measured relatively easily as the discrimination information. The voltage change is caused by the phenomenon of gas movement between the fuel electrode and the oxidant electrode. The gas transfer between the electrodes is, for example, in addition to the convection transfer in which the pressure difference between the electrodes becomes the driving force when a defect occurs in the electrolyte membrane, and the dissolution and diffusion in which the gas concentration difference becomes the driving force even when no defect occurs. There is a move. This amount of dissolution / diffusion transfer varies greatly depending on the temperature and water content of each electrolyte membrane. For example, the amount of dissolution / diffusion transfer may be so large that it cannot be ignored.

  Thus, in the above background art, failure detection is performed without considering dissolution / diffusion movement. Therefore, in fuel cells for automobiles that are operated at various temperatures and humidified conditions, it is difficult to ensure both fault detection capability so that even minute defects can be detected accurately and avoid misdiagnosis. A problem occurs.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a fuel cell failure diagnosis device that achieves both failure detection capability and avoidance of erroneous diagnosis.

  The present invention provides a fuel cell formed by laminating at least one unit cell having an electrolyte membrane sandwiched between an anode and a cathode, temperature detecting means for detecting the temperature of the fuel cell, or At least one of moisture content detecting means for detecting or estimating the moisture content. Further, a judgment value setting means for setting a judgment value that is a threshold value for performing a failure diagnosis of the fuel cell according to an output of the temperature detection means or the moisture content detection means, and the judgment value is used to set the judgment value. Diagnostic means for performing a failure diagnosis of the fuel cell.

  In this way, by setting the judgment value according to the fuel cell temperature or the water content of the electrolyte membrane, the amount of gas transfer between the anode and the cathode due to the dissolution and diffusion transfer that changes according to the water content of the fuel cell or the electrolyte membrane can be set. The failure can be diagnosed in consideration. As a result, both failure diagnosis capability and avoidance of misdiagnosis can be improved.

  A first embodiment will be described. A schematic configuration of a failure diagnosis apparatus for the fuel cell 10 is shown in FIG.

  The fuel cell 10 is configured by stacking a plurality of unit cells 1 each having an electrolyte membrane 2 as shown in FIG. 1A sandwiched between an anode 10a and a cathode 10c. Gaskets 3 are provided around the anode 10a and the cathode 10c, respectively, to prevent a short circuit between the anode 10a and the cathode 10c (hereinafter referred to as “between electrodes”) and to prevent leakage of a reaction gas supplied to each of them.

  Further, as shown in FIG. 1B, fuel gas supply means 11 for supplying fuel gas to the anode 10a of the fuel cell 10 constituted by stacking a plurality of unit cells 1 and supplying oxidant gas to the cathode 10c, An oxidant gas supply means 13 is provided. Furthermore, a fuel gas flow rate control means 12 for controlling the fuel gas flow rate q introduced into the anode 10a and an oxidant gas flow rate control means 14 for controlling the oxidant gas flow rate Q introduced into the cathode 10c are provided.

  In addition, voltage detecting means 15 for detecting the battery voltage V of the fuel cell 10 is provided. Here, the voltage detection means 15 is a means for detecting the battery voltage V of the fuel cell 10, but this is not restrictive. For example, it may be configured by a plurality of voltage sensors that detect the voltage of the unit cell 1 or may be configured by a plurality of voltage sensors that detect the voltage of the assembled battery in which a predetermined number of unit cells 1 are stacked. Further, a temperature detection means 16 for detecting the temperature of the fuel cell 10 is provided. Here, the temperature detection means 16 is configured to detect the temperature of the electrolyte membrane 2. Furthermore, a failure diagnosis control means 21 for controlling the failure diagnosis of the fuel cell 10 from the outputs of the voltage detection means 15 and the temperature detection means 16 is provided.

  During normal operation, a fuel gas is supplied to the anode 10a of the fuel cell 10 and an oxidant gas is supplied to the cathode 10c to generate a power generation reaction. At this time, since the anode 10a and the cathode 10c are separated from each other in the unit cell 1 by the electrolyte membrane 2, the fuel gas and the oxidant gas do not react directly, but protons move in the electrolyte membrane 2 and each electrode A power generation reaction occurs at 1a and 1c.

  Here, when the fuel gas leaks to the cathode 10c, or conversely, the oxidant gas leaks to the anode 10a, the fuel gas and the oxidant gas are directly reacted and consumed. As a result, there is a shortage of reaction gas for power generation, and reaction heat is generated in the reaction portion, resulting in excessive temperature rise. The leakage of the reaction gas between the anode 10a and the cathode 10c is caused by, for example, a defect in the electrolyte membrane 2 or a defect in the gasket 3 provided around the anode 10a and the cathode 10c.

  Therefore, the failure diagnosis of the fuel cell 10 is performed by determining whether or not the leakage of the reaction gas due to the defect of the fuel cell 10 occurs. When power generation is stopped, failure diagnosis of the fuel cell 10 is performed based on the amount of voltage change when the amount of reactant gas supplied is changed.

  Here, the voltage change is caused by the movement phenomenon of the reaction gas between the electrodes. As a reaction phenomenon of the reaction gas, not only the convection movement caused by the pressure difference between the electrodes when the defect occurs in the electrolyte membrane 2 or the like, but also the case where the defect does not occur in the fuel cell 10. There may be a case where dissolution / diffusion movement in which the concentration difference becomes a driving force occurs.

  Here, the amount of gas movement due to dissolution and diffusion changes according to the fuel cell temperature T. For example, when the hydrogen partial pressure difference between the anode 10a and the cathode 10c is constant and the moisture content of the electrolyte membrane 2 is constant, the amount of fuel gas transferred from the anode 10a to the cathode 10c is as shown in FIG. That is, as the temperature of the fuel cell 10 increases, the amount of fuel gas movement due to dissolution and diffusion increases.

Therefore, the failure diagnosis of the fuel cell 10, the diagnosis carried out by the solution-diffusion determined value Cj _a and the detected voltage variation [Delta] V _a in consideration of the voltage variation caused by the gas transfer due. Here, setting the determination value Cj _a according to the fuel cell temperature T, by comparing the voltage change amount [Delta] V _a in the case of changing the reaction gas supply amount and the determined value Cj _a, failure of the fuel cell 10 Diagnose.

  Next, the flow of failure diagnosis of the fuel cell 10 will be described using the flowchart shown in FIG. This flow is repeated every predetermined time from the start to the end of the fuel cell system.

  Here, failure diagnosis is performed when power generation of the fuel cell system is stopped. However, the present invention is not limited to this, and may be executed when, for example, the fuel cell 10 is performing predetermined low-current power generation.

In step S1, it is determined whether or not power generation is stopped. If the power generation is not stopped, failure diagnosis is not performed and this flow is terminated. If power generation is stopped, the process proceeds to step S2, by adjusting the fuel gas flow control means 12 to control the predetermined value q ₀ which is set in advance the fuel gas flow rate q. In step S3, by adjusting the oxidant gas flow control means 14, it sets the oxidant gas supply amount Q to the predetermined value Q _1. Next, in step S4, the battery voltage V _1a is detected using the voltage detection means 15. In step S5, by adjusting the oxidant gas flow control means 14, it sets the oxidant gas supply amount Q to the predetermined value Q _2. Here, the predetermined values Q ₁ and Q ₂ are different values, for example, Q ₁ > Q ₂ . Further, the predetermined value Q ₁ may be set with respect to the predetermined value q ₀ so that the pressure difference between the anode 10a and the cathode 10c is 0 or very small. In step S6, the battery voltage V _2a is detected using the voltage detection means 15.

At this time, as shown in FIG. 4, the battery voltage V is also reduced by reducing the oxidant gas flow rate Q in the normal state. When defects are generated in the electrolyte membrane 2 and the like, the fuel gas leaks from the anode 10a to the cathode 10c by reducing the oxidant gas flow rate Q. As a result, when there is a defect, in addition to the normal battery voltage reduction, the battery voltage also decreases due to the direct reaction of the leaked reaction gas. The quantity ΔV _a (= V _1a −V _2a ) increases. The voltage change amount ΔV _a includes the pressure change amount due to the above-described dissolution diffusion movement.

Therefore, in step S7, the fuel cell temperature T is read by reading the output of the temperature detection means 16. In step S8, depending on the fuel cell temperature T, it sets a decision value Cj _a voltage change amount [Delta] V _a when the oxidant gas flow rate was varied from Q ₁ to Q _2. In accordance with a change in the gas transfer amount to the fuel cell temperature T as shown in FIG. 2, the decision value Cj _a for the fuel cell temperature T is obtained in advance and stored it as a map shown in FIG. Or, 5 in advance by experiment or the like, the amount of change [Delta] V _a in the case of changing the oxidant gas amount Q in the normal, advance determined for a plurality of fuel cell temperature T, and sets a future decision value Cj _a Is stored as a map as shown in FIG. The higher the fuel cell temperature T, setting a large determination value Cj _a at diagnosis.

In step S9, by comparing the decision value Cj _a pressure change amount [Delta] V _a, the failure diagnosis. If the amount of change [Delta] V _a is greater than the determination value Cj _a is diagnosed as faulty process proceeds to step S10, the failure process. For example, control is performed so as to warn the driver by blinking a light indicating a defect. On the other hand, in step S9, if the [Delta] V _a is less than determination value Cj _a is diagnosed as no fault and the flow ends.

Here, the diagnosis is performed by reducing the oxidant gas flow rate with the predetermined value Q ₁ > Q ₂ , but it may be Q ₁ <Q ₂ . In this case, the battery pressure V is V _1a <V _2a . Further, instead of the oxidant gas flow rate Q, the fuel gas flow rate q may be changed.

Thus, a failure diagnosis by comparing the decision value Cj _a set according to the voltage variation [Delta] V _a and the fuel cell temperature T in the case of the oxidant gas flow rate was varied from Q ₁ to Q _2. This makes it possible to reflect the change in the battery voltage V by the solution-diffusion move with temperature dependency determination value Cj _a. As a result, it is possible to improve both fault diagnosis capability and avoid misdiagnosis.

  Next, the effect of this embodiment will be described.

A fuel cell 10 in which at least one unit cell 1 having an electrolyte membrane 2 sandwiched between an anode 10a and a cathode 10c is stacked, and a temperature detecting means 16 for detecting the temperature T of the fuel cell 10 are provided. . Further, the determination value setting means for setting a judgment value Cj _a is a threshold for performing failure diagnosis of the fuel cell 10 according to an output of the temperature detecting means 16 (S8), the fuel cell 10 by using the determination value Cj _a Diagnostic means (S9) for performing a failure diagnosis of In this way, by setting the determination value Cj _a according to the fuel cell temperature T, it is possible to make a diagnosis by considering the influence of the voltage change due to solution-diffusion transfer varies depending on the temperature. As a result, both failure diagnosis capability and avoidance of misdiagnosis can be improved.

Here, a voltage detection means 15 for detecting the battery voltage for each unit cell 1 or for each assembled battery in which a plurality of unit cells 1 are connected in series is provided, and the judgment value setting means (S8) is a temperature detection means 16. depending on the output compare, sets a decision value Cj _a voltage state of the fuel cell 10, the diagnostic means (S9) includes a voltage state of the fuel cell 10 obtained from the voltage detecting means 15, and a decision value Cj _a Execute fault diagnosis. Thus, the voltage state of the fuel cell 10, by comparing the decision value Cj _a set according to the fuel cell temperature T, it is possible to perform failure diagnosis in consideration of the influence of the voltage change due to solution-diffusion movement .

Furthermore, the voltage detector 15 for detecting the battery voltage for each unit cell 1 or for each assembled battery in which a plurality of unit cells 1 are connected in series, and the reactive gas flow rate adjustment for adjusting the reactive gas flow rate supplied to the fuel cell 10 Means. Here, as the reactive gas flow rate adjusting means, a fuel gas flow rate adjusting means 12 and an oxidant gas flow rate adjusting means 14 are provided. Determination value setting means (S8) sets the voltage variation determination value Cj _a when the flow rate of the reaction gas was varied from the predetermined value Q ₁ to a predetermined value Q _2. Diagnostic means (S9) is carried out and the detected value [Delta] V _a voltage change amount when changing the reaction gas flow rate, a failure diagnosis by comparing the decision value Cj _a. Thus, the determination value Cj _a voltage change when the reaction gas flow rate by a predetermined amount changed set according to the fuel cell temperature T, by performing the failure diagnosis, taking into account the influence of the voltage change due to solution-diffusion movement Diagnosis can be made.

  Next, a second embodiment will be described. The configuration of the failure diagnosis apparatus for the fuel cell 10 is shown in FIG. 1 as in the first embodiment. Hereinafter, a description will be given centering on differences from the first embodiment.

Even when the oxidant gas flow rate Q is adjusted to the predetermined amounts Q ₁ and Q ₂ , a certain amount of time is required until the gas composition distribution in the unit cell 1 becomes steady and stable. Therefore, after adjusting the oxidant gas supply amount Q to the predetermined values Q ₁ and Q ₂ , the battery voltages V _1a and V _2a are detected after the predetermined times T _1a0 and T _{2a0 have} elapsed. Thus, by detecting a stable battery voltage V and calculating the voltage change amount [Delta] V _a, by using the failure diagnosis, it is possible to achieve both the diagnosis avoiding erroneous further improve the fault diagnostic capability.

  The failure diagnosis control of the fuel cell 10 will be described using the flowchart shown in FIG.

Steps S21 to S23 are the same as steps S1 to S3. In step S24, an elapsed time T _1a after the oxidant gas flow rate Q is adjusted to a predetermined value Q ₁ is counted. That is, T _1a → T _1a + t _1a . Next, in step S25, it is determined whether or not the elapsed time T _1a is _{equal to} or _longer than a predetermined time T _1a0 . If the elapsed time T _1a has not reached the predetermined time T _1a0 , the process returns to step S24. Note that t _1a is the time required for the control in steps S24 and S25.

When the elapsed time T _1a is determined to have reached the predetermined time T _1a0 In step S25, the process proceeds to step S26, detects a battery voltage V _1a. Next, in step S27, adjusting the oxidant gas flow rate Q to a predetermined value Q _2. In step S28, the elapsed time T _2a after the adjustment to the predetermined value Q ₂ is counted. That is, T _2a → T _2a + t _2a . Next, in step S29, it is determined whether or not the elapsed time T _2a is _{equal to} or _longer than the predetermined time T _2a0 . If the elapsed time T _2a has not reached the predetermined time T _2a0 , the process returns to step S28. Note that t _2a is the time required for the control in steps S28 and S29.

When the elapsed time T _2a is judged to have reached the predetermined time T _2a0 in step S29, the process proceeds to step S30, detects a battery voltage V _2a. Thereafter, Steps S31 to S34 are the same as Steps S7 to S10, and a failure diagnosis is performed by setting _a judgment value Cja corresponding to the fuel cell temperature T. Further, in step S35, the elapsed times T _1a and T _2a are reset to 0, and this flow ends.

As described above, after the oxidant gas flow rate Q is adjusted to the predetermined amounts Q ₁ and Q ₂ , the battery voltages V _1a and V _2a are detected after the predetermined times T _1a0 and T _2a0 have elapsed.

  Next, the effect of this embodiment will be described. Only the effects different from those of the first embodiment will be described below.

After the oxidant gas flow rate Q is changed, the voltage detection means 15 detects the voltage after a predetermined time T _1a0 and T _{2a0 have} elapsed. As a result, the gas composition distribution of the reaction gas in the fuel cell 10 becomes a steady state, and the voltages V _1a and V _2a are detected after being stabilized, so that a more accurate failure diagnosis can be performed.

  Next, a third embodiment will be described. FIG. 7 shows the configuration of the failure diagnosis apparatus for the fuel cell 10. Hereinafter, a description will be given centering on portions different from the first embodiment.

  A fuel gas pressure control means 17 and an oxidant gas pressure control means 18 for adjusting respective pressures in the anode 10a and the cathode 10c are provided on the downstream side of the anode 10a and the cathode 10c of the fuel cell 10. Here, the fuel gas pressure control means 17 and the oxidant gas pressure control means 18 are each constituted by a pressure regulating valve.

  Next, failure diagnosis control of the fuel cell 10 will be described using the flowchart of FIG.

Depending on the fuel cell temperature T, it sets the determination value Cj _b of the voltage change amount when changing the interelectrode gas pressure difference P between the anode 10a and the cathode 10c, compared therewith the detected value [Delta] V _b that Perform fault diagnosis with

In step S41, it is determined whether or not power generation is stopped. If the power generation is not stopped, this flow is terminated. If the power generation is stopped, the process proceeds to step S42. In step S42, the inter-electrode gas differential pressure P is adjusted to a predetermined value P ₁ by adjusting the fuel gas pressure adjusting means 17 and the oxidant gas pressure adjusting means 18. In step S43, the battery voltage V _1b is detected. Next, in step S44, adjusting the interelectrode gas differential pressure P to a predetermined value P _2. In step S45, the battery voltage V _2b when the inter-electrode gas differential pressure P is adjusted to P ₂ is detected.

Here, the predetermined values P ₁ and P ₂ are different values, for example, P ₁ <P ₂ . On the other hand, the battery voltage V _satisfies V _1b > V _{2b as} shown in FIG. When the inter-electrode gas differential pressure P is changed, the change amount ΔV _b (= V _1b −V _2b ) of the battery voltage V becomes larger at the time of failure than the normal value.

Toward the step S46～S49, similarly to step S7 to S10, and sets the determined values Cj _b in accordance with the fuel cell temperature T, the failure diagnosis. The determination value Cj _b is in response to changes in the gas transfer amount to the fuel cell temperature T as shown in FIG. 2, is previously obtained judgment values Cj _b for the fuel cell temperature T, as shown in figure 10 Remember it as a map. Alternatively, an amount of voltage change ΔV _b when the inter-electrode gas differential pressure P is changed from P ₁ to P ₂ is obtained for a plurality of fuel cell temperatures T by an experiment or the like in advance, and thereby the judgment value Cj _b is set and stored as a map as shown in FIG. The higher the fuel cell temperature T, setting a large determination value Cj _b at diagnosis.

In steps S41 and S43, when the interelectrode gas differential pressure P is set to the predetermined values P ₁ and P ₂ , the pressures of the anode 10a and the cathode 10c may be measured using pressure detection means (not shown). However, for example, the opening degree of the pressure adjusting valve used as the fuel gas pressure adjusting means 17 and the oxidant gas pressure adjusting means 18 may be set in advance through experiments or the like.

Accordingly, since the influence of the battery voltage changes in the solution-diffusion move with the temperature dependence is reflected in decision value Cj _b, it is possible to achieve both the diagnosis avoiding erroneous increase failure diagnostic capabilities.

  Next, the effect of this embodiment will be described. Only the effects different from those of the first embodiment will be described below.

Voltage detection means for detecting the battery voltage for each unit cell 1 or for each assembled battery in which a plurality of unit cells 1 are connected in series, and fuel gas pressure control for adjusting the gas pressure difference P between the anode 10a and the cathode 10c Means 17 and oxidant gas pressure control means 18. Determination value setting means (S47) sets the determination value Cj _b of the voltage change amount when changing the interelectrode gas differential pressure P from the predetermined value P ₁ to P _2. Diagnostic means (S48) performs the detection value [Delta] V _b of the voltage change amount when changing the interelectrode gas differential pressure P, and the failure diagnosis by comparing the decision value Cj _b. Thus, by using the set fault diagnosis judgment value Cj _b of the voltage change when the inter-electrode gas differential pressure P by a predetermined amount varies depending on the fuel cell temperature T, the influence of the voltage change due to solution-diffusion movement It is possible to perform failure diagnosis in consideration of

  Next, a fourth embodiment will be described. The configuration of the failure diagnosis apparatus for the fuel cell 10 is shown in FIG. 7 as in the third embodiment. Hereinafter, a description will be given centering on differences from the third embodiment.

  The failure diagnosis control of the fuel cell 10 will be described with reference to the flowchart of FIG. Here, the failure diagnosis of the fuel cell 10 is performed in a state where the supply of the oxidant gas is stopped.

  In step S51, it is determined whether or not power generation is stopped. If the power generation is not stopped, this flow is terminated, and the process proceeds to step S52 when power generation is stopped. In step S52, the supply of the oxidant gas is stopped. Hereinafter, steps S53 to S60 are the same as steps S42 to S49.

  Next, the effect of this embodiment will be described. Hereinafter, a description will be given centering on differences from the third embodiment.

  At the time of failure diagnosis, the inter-electrode gas differential pressure P is changed while the supply of the oxidant gas introduced into the cathode 10c is stopped. Thus, if supply of oxidant gas is stopped at the time of failure diagnosis of the fuel cell 10, new oxidant gas is not supplied for oxygen consumption at the cathode 10c. Therefore, even when the hydrogen transfer rate from the anode 10a to the cathode 10c is the same, the rate of decrease in the amount of oxygen present in the cathode 10c increases. As a result, the amount of change in the battery voltage V increases, and the fault diagnosis capability can be improved.

  Next, a fifth embodiment will be described. The configuration of the failure diagnosis apparatus for the fuel cell 10 is shown in FIG. 7 as in the third embodiment. Hereinafter, a description will be given centering on differences from the third embodiment.

Even when the inter-electrode gas differential pressure P is adjusted to the predetermined values P ₁ and P ₂ , a certain amount of time is required until the gas composition distribution in the unit cell 1 becomes steady and stable. Therefore, after the inter-electrode gas differential pressure P is controlled to the predetermined values P ₁ and P ₂ , the battery voltages V _1b and V _2b are detected after the predetermined times T _1b0 and T _{2b0 have} elapsed.

  The failure diagnosis control of the fuel cell 10 is shown in the flowchart of FIG.

When the inter-electrode gas differential pressure P is adjusted to the predetermined values P ₁ and P ₂ in each of steps S62 and S66, the elapsed time T _1b and T ₂ after the adjustment to the predetermined values P ₁ and P ₂ in steps S63 and S67. Count _2b . Next, in steps S64 and S68, it is determined whether or not the elapsed times T _1b and T _2b have reached predetermined times T _1b0 and T _2b0 , respectively. If the elapsed times T _1b and T _2b have not reached the predetermined times T _1b0 and T _2b0 , the process returns to steps S63 and S67. When the elapsed times T _1b and T _2b reach the predetermined times T _1b0 and T _2b0 , the process proceeds to steps S65 and S69, and the battery voltages V _1b and V _2b are detected.

  Next, the effect of this embodiment will be described. Hereinafter, only effects different from those of the third embodiment will be described.

The voltage is detected by the voltage detection means 15 after a predetermined time T _1b0 and T _2b0 after changing the inter-electrode gas differential pressure P. Thereby, the voltage values V _1b and V _2b can be detected after the gas composition component distribution of the reaction gas in the fuel cell 10 is stabilized. As a result, since the stable battery voltage V is detected and the voltage change amount ΔV _b is calculated and used for failure diagnosis, it is possible to further improve the failure diagnosis capability and avoid misdiagnosis.

  Next, a sixth embodiment will be described. The configuration of the failure diagnosis apparatus for the fuel cell 10 is shown in FIG. 7 as in the third embodiment. Hereinafter, a description will be given centering on differences from the third embodiment.

According to the fuel cell temperature T, a predetermined amount of fuel gas is supplied, and a determination value Cj _c of the battery voltage when a predetermined time T _c0 has elapsed since the supply of the oxidant gas is stopped is set and detected. by comparing the values V _c, the failure diagnosis of the fuel cell 10.

  The failure diagnosis control of the fuel cell 10 is shown in the flowchart of FIG.

In step S80, it is determined whether power generation is stopped. If not stopped, the present flow is terminated. If stopped, the process proceeds to step S81. In step S81, the fuel gas is adjusted to a predetermined pressure _Pc . Here, the predetermined pressure _Pc is set to a pressure higher than that in the cathode 10c. In step S82, the supply of the oxidant gas is stopped. In step S83, an elapsed time _Tc after the supply of the oxidant gas is stopped is counted. That is, T _c → T _c + t _c . Next, in step S84, it is determined whether or not the elapsed time _Tc has reached a predetermined time _Tc0 . If not, the process returns to step S83, and if reached, the process proceeds to step S85. In step S85, the battery voltage V _c is measured.

Next, in step S86, the fuel cell temperature T is detected, and in step S87, a diagnostic value Cj _c is set. Here, through experiments or the like, the amount of voltage decrease after the elapse of a predetermined time T _c0 after the fuel gas 10 is set to the predetermined pressure P _c and the oxidant gas supply is stopped when the fuel cell 10 is normal is set to a plurality of values. A determination value Cj _c is set for each fuel cell temperature T and stored as a map as shown in FIG. As shown in FIG. 2, as the fuel cell temperature T increases, the amount of gas movement due to dissolution and diffusion increases, so that the battery voltage V _c detected after a predetermined time T _c0 decreases. Therefore, as shown in FIG. 14, the determination value Cj _c is set to be smaller as the fuel cell temperature T is higher.

In step S88, the detected battery voltage V _c is compared with the determination value Cj _c . When the battery voltage V _c is equal to or higher than the judgment value Cj _c , it is determined that no failure has occurred. Next, in step S90, the elapsed time _Tc is reset to 0, and this flow ends.

As described above, when the fuel gas is adjusted to a predetermined pressure and the supply of the oxidant gas is stopped, the movement of the reaction gas between the electrodes is caused by dissolution and diffusion at the normal time. On the other hand, in the event of a failure, convection movement occurs in addition to dissolution diffusion movement, so the total amount of gas that moves between the electrodes increases. As a result, at the time of failure, the amount of voltage drop after the supply of the oxidant gas is stopped becomes larger than that at the normal time. Therefore, when the battery voltage V _c is smaller than the determination value Cj _c, it is determined that a voltage drop has occurred due to leakage of the reaction gas. At this time, since the amount of gas movement due to normal dissolution and diffusion changes with respect to the fuel cell temperature T, the judgment value Cj _c is changed according to the fuel cell temperature T. As a result, it is possible to improve both failure diagnosis capability and avoid misdiagnosis.

  Next, the effect of this embodiment will be described. Hereinafter, only effects different from those of the third embodiment will be described.

Voltage detecting means 15 for detecting a battery voltage for each unit cell 1 or for each assembled battery in which a plurality of unit cells 1 are connected in series, and a fuel gas pressure adjusting means 17 for adjusting the pressure of the anode 10a are provided. Determination value setting means (S87) sets the pressure of the anode 10a to a predetermined pressure P _c, stop the supply of the reaction gas to the cathode 10c, the determination value Cj _c battery voltage after a predetermined time T _c0 Set. Here, the predetermined pressure value _Pc is set so that the anode 10a has a higher pressure value than the cathode 10c. The diagnosis means (S88) determines the detected value V _c of the voltage detection means 15 after a predetermined time T _c0 after setting the anode 10a to the predetermined pressure P _c0 and stopping the supply of the reaction gas to the cathode 10c. the failure diagnosis by comparing the values Cj _c. As a result, it is possible to improve both failure diagnosis capability and avoid misdiagnosis.

  Next, a seventh embodiment will be described. The configuration of the failure diagnosis apparatus for the fuel cell 10 is shown in FIG. 7 as in the third embodiment. Hereinafter, a description will be given centering on differences from the third embodiment.

With the fuel gas set to a predetermined pressure P _d and the supply of the oxidant gas stopped, a judgment value Cj _d for the time until the battery voltage V _d drops to the predetermined value V _d0 is set. by comparing the T _d, the failure diagnosis of the fuel cell 10. The failure diagnosis control of the fuel cell 10 will be described using the flowchart of FIG.

In step S91, it is determined whether power generation is being performed. If it is being performed, this flow is terminated. When the power generation is not performed, the process proceeds to step S92, the fuel gas is set to a predetermined pressure P _d, to stop the supply of the oxidizing gas in Step S93. Here, the predetermined pressure value _Pd is set so that the anode 10a has a higher pressure value than the cathode 10c.

In step S94, an elapsed time _Td after the oxidant gas is stopped is counted. Next, in step S95, detects the battery voltage V _d. In step S96, the battery voltage V _d to determine whether the difference is less than a predetermined value V _d0. If the battery voltage V _d is greater than or equal to the predetermined value V _d0 , the process returns to step S94. When the battery voltage V _d drops below the predetermined value V _d0 , the process proceeds to step S97.

In step S97, it detects the fuel cell temperature T, in step S98, sets a decision value Cjd for determining fault by comparing the time T _d to drop to a predetermined value V _d. Here, when the fuel cell temperature T is high, even when the fuel cell 10 is not defective, the amount of gas movement due to dissolution and diffusion is large, and the cell voltage V _d decreases at a relatively high rate. Therefore, when the fuel cell temperature T is high, the judgment value Cj _d is set to a small value as shown in FIG. 16, and a failure occurs when the battery voltage V _d becomes lower than the predetermined value V _{d0 in a} shorter time. Judge.

It should be _noted that the time T _d required for the battery voltage V _d to decrease to the predetermined value V _d0 in a state where the fuel gas is set to the predetermined pressure P _d at normal time and the supply of the oxidant gas is stopped by an experiment or the like calculated for each of the plurality of fuel cell temperature T, it is stored as a map shown in FIG. 16 by setting the diagnostic value Cj _d than this.

Next, in step S99, the time T _d required until the battery voltage V _d drops to the predetermined value V _d0 is compared with the judgment value Cj _d . Time T _d is determined to be normal in the case of more than judgment value Cj _d. If time T _d is less than the decision value Cj _d determines that the failure has occurred, the failure process in step S100. If such a diagnosis is performed, in step S101, the time _Td is reset to 0, and this flow ends.

In this way, when a predetermined amount of fuel gas is supplied and the supply of the oxidant gas is stopped, the movement of the reaction gas between the electrodes is caused by dissolution and diffusion at the normal time. On the other hand, at the time of failure, convection movement occurs in addition to dissolution / diffusion movement, so the total amount of gas moving between the electrodes increases. As a result, at the time of failure, the voltage drop rate after the supply of the oxidant gas is stopped becomes larger than that at the normal time. Therefore, when the battery voltage V _d becomes lower than the predetermined value V _d0 in a time shorter than the determination value Cj _d , it is determined that the reaction gas has leaked. At this time, since the amount of gas movement due to normal dissolution and diffusion changes with respect to the fuel cell temperature T, the judgment value Cj _c is changed according to the fuel cell temperature T.

  Next, the effect of this embodiment will be described. Hereinafter, only effects different from those of the third embodiment will be described.

Voltage detecting means 15 for detecting a battery voltage for each unit cell 1 or for each assembled battery in which a plurality of unit cells 1 are connected in series, and a fuel gas pressure adjusting means 17 for adjusting the pressure of the anode 10a are provided. Determination value setting means (S98) sets the pressure of the anode 10a to a predetermined pressure value P _d, stop the supply of the reaction gas to the cathode 10c, the time required to drop to a predetermined voltage V _d0 threshold Is set as the judgment value Cj _d . Here, the predetermined pressure value _Pd is set so that the anode 10a has a higher pressure value than the cathode 10c. Determination means (S99) sets the anode 10a pressure to a predetermined pressure value P _d, stop the supply of the reaction gas to the cathode 10c, until the detection value of the voltage detecting means 15 is lowered to a predetermined voltage V _d0 and time T _d of the failure diagnosis by comparing the decision value Cj _d. As a result, it is possible to improve both failure diagnosis capability and avoid misdiagnosis.

  Next, an eighth embodiment will be described. The configuration of the failure diagnosis apparatus for the fuel cell 10 is shown in FIG. 7 as in the third embodiment. Hereinafter, a description will be given centering on differences from the sixth embodiment.

  The failure diagnosis control of the fuel cell 10 is shown in the flowchart of FIG.

In step S112, it sets the oxidant gas at a predetermined pressure P _e, to stop the supply of fuel gas at step S113. Here, the cathode 10c sets a predetermined pressure value P _e as a higher pressure value than the anode 10a. Further, in step S114, S115, the supply of fuel gas to measure the elapsed time T _e from the stop, which determines whether or not reached a predetermined time T _e0. Other parts are the same as those in the flowchart of FIG.

As described above, even when the oxidant gas is set to the predetermined pressure _Pe and the supply of the fuel gas is stopped, both the improvement of the fault diagnosis capability and the avoidance of misdiagnosis can be achieved as in the sixth embodiment. A possible failure diagnosis of the fuel cell 10 can be performed.

  Next, the effect of this embodiment will be described. Only the effects different from those of the sixth embodiment will be described below.

Voltage detecting means 15 for detecting a battery voltage for each unit cell 1 or each assembled battery in which a plurality of unit cells 1 are connected in series, and an oxidant gas pressure adjusting means 18 for adjusting the pressure of the cathode 10c are provided. . Determination value setting means (S118) in response to the output of the temperature detection means, set the pressure of the cathode 10c to a predetermined force value P _e, after stopping the supply of the reaction gas to the anode 10a, the predetermined time T _e0 setting a decision value Cj _e of the voltage detecting means 15 after. Here, the predetermined pressure value _Pe is set so that the cathode 10c has a higher pressure value than the anode 10a. Diagnostic means (S119) sets the pressure of the cathode 10c to a predetermined pressure value P _e, after stopping the supply of the reaction gas to the anode 10a, the detection value V _e of the voltage detecting means 16 after a predetermined time T _e0 And a judgment value Cj _e is compared to perform a failure diagnosis. As a result, it is possible to improve both failure diagnosis capability and avoid misdiagnosis.

  Next, a ninth embodiment will be described. FIG. 7 shows the configuration of the failure diagnosis apparatus for the fuel cell 10. Hereinafter, a description will be given centering on differences from the seventh embodiment.

  The failure diagnosis control of the fuel cell 10 is shown in the flowchart of FIG.

If it is determined the power generation stops and in step S131, the in step S132, sets the oxidant gas at a predetermined pressure P _f, to stop the supply of fuel gas in step S133. Here, the predetermined pressure value P _f is set so that the cathode 10c has a higher pressure value than the anode 10a. Further, in step S134～S136, the supply of fuel gas to count the time T _f to decrease from the stop to a predetermined voltage V _f, in step S139, by comparing the diagnostic value Cj _f and time T _f Perform fault diagnosis with Other parts are the same as those in the flowchart of FIG.

Thus, even when the oxidant gas is set to the predetermined pressure P _f and the supply of the fuel gas is stopped, both the improvement of the failure diagnosis capability and the avoidance of misdiagnosis can be achieved as in the seventh embodiment. A possible failure diagnosis of the fuel cell 10 can be performed.

  Next, the effect of this embodiment will be described. Only the effects different from those of the seventh embodiment will be described below.

Voltage detecting means 15 for detecting a battery voltage for each unit cell 1 or each assembled battery in which a plurality of unit cells 1 are connected in series, and an oxidant gas pressure adjusting means 18 for adjusting the pressure of the cathode 10c are provided. . Determination value setting means (S138) sets the pressure of the cathode 10c to a predetermined pressure value P _f, after stopping the supply of the reaction gas to the anode 10a, the time required to drop to a predetermined voltage V _f0 determined Set the value Cj _f . Here, the predetermined pressure value P _f is set so that the cathode 10c has a higher pressure value than the anode 10a. Diagnostic means (S139) sets the pressure of the cathode 10c to a predetermined pressure value P _f, after stopping the supply of the reaction gas to the anode 10a, the detection value of the voltage detecting means 16 is lowered to a predetermined voltage V _f0 and time T _f until, the failure diagnosis by comparing the decision value Cj _f. As a result, it is possible to improve both failure diagnosis capability and avoid misdiagnosis.

  Next, a tenth embodiment will be described. FIG. 19 shows the configuration of the failure diagnosis apparatus for the fuel cell 10. Hereinafter, a description will be given centering on differences from the third embodiment.

  In addition to the fuel gas pressure control means 17 and the oxidant gas pressure control means 18 provided on the downstream side of the anode 10a and the cathode 10c, a fuel electrode closing means 19 for selectively closing the anode 10a is provided. Here, the fuel electrode closing means 19 is constituted by two on-off valves that selectively close the inlet and the outlet of the anode 10a. Further, in place of the voltage detection means 15, a fuel gas pressure detection means 20 for detecting the fuel gas pressure in the anode 10a is provided.

Here, at the time of failure diagnosis of the fuel cell 10, the supply of the oxidant gas is stopped and the anode 10a is closed while being pressurized to a predetermined pressure _Pg0 . Here, the predetermined pressure value _Pg0 is set so that the anode 10a has a higher pressure value than the cathode 10c. If the pressure in the anode 10a after a predetermined time T _g has elapsed determined value Cj _g smaller in this state, it is determined that a failure has occurred.

  The failure diagnosis control of the fuel cell 10 will be described using the flowchart of FIG.

In step S151, it is determined whether or not the power generation is stopped. If the power generation is stopped, the process proceeds to step S152, and the supply of the oxidant gas is stopped. Next, in step S153, the inside of the anode 10a is pressurized to a predetermined value _Pg0 by adjusting the fuel gas pressure control means 17. Next, in step S154, the anode 10a is closed by the fuel electrode closing means 19.

In step S155, S156, if it is determined from the closed to the anode 10a and the predetermined time T _g0 elapsed, in step S157, detects the pressure P _g in the anode 10a. In step S158, the fuel cell temperature T is measured, and in step S159, a judgment value Cj _g is set.

Here, when the fuel cell temperature T is high, there is much movement of the reaction gas between the electrodes (FIG. 2), so that the amount of pressure drop in the anode 10a increases even during normal operation. Therefore, when the fuel cell temperature T is large, by setting a small value judgment value Cj _g as shown in FIG. 21, the solution-diffusion of the pressure erroneous diagnosis fault occurs when reduced by Can be prevented. Here, by experiment or the like, after closing the anode 10a pressurized to a predetermined value P _g0, when a predetermined time T _g0 has elapsed, the pressure P _g a plurality of fuel cell temperature T in the anode 10a in the normal Ask every time. In response to this, a judgment value Cj _g is set and stored as a map as shown in FIG.

Next, at step S160, compares the pressure P _g of the detected anode 10a and determines values Cj _g. If, on the other hand the pressure P _g is not less than determination value Cj _g, in the case of less than the failure process in step S161 it is determined that failure. In step S162, the elapsed time T _g of the after closing the anode 10a is reset to 0, the flow ends.

Thus, after pressurization, failure diagnosis of the fuel cell 10 is performed according to the pressure change in the closed anode 10a. At this time, when the fuel cell temperature T is high, the pressure P _g of the anode 10a to the normal by the solution-diffusion tends to decrease. Therefore, the judgment value Cj _g is set according to the fuel cell temperature T.

  Next, the effect of this embodiment will be described. Hereinafter, only effects different from those of the third embodiment will be described.

The fuel gas pressure detecting means 20 for detecting the fuel gas pressure in the fuel cell 10 is provided, and the judgment value setting means (S159) is in a voltage state or a fuel gas pressure state of the fuel cell 10 according to the output of the temperature detecting means 16. Is set as the judgment value Cj _g . The diagnosis unit (S160) performs failure diagnosis by comparing the determination value Cjg with the state of the fuel gas pressure of the fuel cell 10 obtained from the fuel gas pressure detection unit 20.

Here, the fuel gas pressure detecting means 20 for detecting the fuel gas pressure in the fuel cell 10, the fuel gas pressure adjusting means 17 for adjusting the pressure of the anode 10a, and the fuel electrode closing means 19 for closing the anode 10a are provided. Prepare. Determination value setting means (S159) from closes the anode 10a pressurized to a predetermined pressure P _g0 in accordance with the output of the temperature detecting means 16 after a predetermined time T _g0 elapsed, determination value of the gas pressure value of the anode 10a Set Cj _g . Here, the predetermined pressure P _g0 is set so that the pressure of the anode 10 a is higher than the pressure of the cathode 1. Diagnostic means (160), comparing the predetermined pressure P _g0 to pressurized the anode 10a from the closed after a predetermined time T _g0 elapsed, the detection value P _g and determined values Cj _g of the gas pressure of the anode 10a Perform fault diagnosis with As a result, it is possible to improve both failure diagnosis capability and avoid misdiagnosis.

  Next, an eleventh embodiment will be described. A failure diagnosis apparatus for the fuel cell 10 is shown in FIG. Hereinafter, a description will be given centering on differences from the tenth embodiment.

Depending on the fuel cell temperature T, the anode 10a closes the pressurized, the pressure P _h in the anode 10a sets the diagnostic value of the time required to decrease to a predetermined value P _h0, which the detection value T _h A failure diagnosis is performed by comparing Here, the predetermined value P _h0 is set so that the anode 10 a has a higher pressure than the cathode 1. The failure diagnosis control of the fuel cell 10 will be described using the flowchart shown in FIG.

Steps S171 to S174 are the same as steps S151 to S154. In step S175, to count the elapsed time T _h from closes the anode 10a. Detecting a pressure P _h in the anode 10a in step S176, the pressure P _h determines whether decreased to a predetermined value P _h1 at step S177. When the pressure P _h can repeat steps S175~S177 until judged reduced to a predetermined value P _h1, it is determined to be decreased, the process proceeds to step S178.

In step S178, the fuel cell temperature T is measured. In step S179, the determination value Cj _h is set according to the fuel cell temperature T. Here, when the fuel cell temperature T is high, the amount of fuel gas to move the machining gap by the solution-diffusion becomes large, the time T _h the pressure P _h in the anode 10a is reduced to a predetermined value P _h1 is small. Therefore, when the fuel cell temperature T is high, the judgment value Cj _h is set small as shown in FIG.

Next, in step S180, by comparing the decision value Cj _h and the elapsed time T _h, is determined to be normal when the time T _h is more than determination value Cj _h, when time T _h is less than the decision value Cj _h Is determined to have failed, and failure processing is performed in step S181. Next, in step S182, the elapsed time T _h is reset to 0, the flow ends.

Thus, a failure diagnosis of the fuel cell 10 in accordance with the time T _h the pressure of the pressurized occluded in the anode 10a is required to decrease to a predetermined value P _h1. At this time, when the fuel cell temperature T is high, the time during which the pressure in the anode 10a drops to the predetermined value _Ph1 is shortened even during normal operation due to dissolution and diffusion. Therefore, the judgment value Cj _h is set according to the fuel cell temperature T.

  Next, the effect of this embodiment will be described. Hereinafter, only effects different from those of the tenth embodiment will be described.

A fuel gas pressure detecting means 20 for detecting the fuel gas pressure in the fuel cell 10, a fuel gas pressure adjusting means 17 for adjusting the pressure of the anode 10a, and a fuel electrode closing means 19 for closing the anode 10a are provided. The judgment value setting means (S179) sets the judgment value Cj _h of the time from when the anode 10a pressurized to the predetermined pressure P _h0 is closed until the voltage drops to the predetermined voltage, according to the output of the temperature detection means 16. . Here, the predetermined value P _h0 is set so that the anode 10a has a higher pressure than the cathode 10c. Diagnostic means (S180) from closes the pressurized anode 10a to a predetermined pressure P _h0, and time T _h required for the output of the fuel gas pressure detection means 20 is lowered to a predetermined value P _h1, determination value Failure diagnosis is performed by comparing Cj _h . As a result, it is possible to improve both failure diagnosis capability and avoid misdiagnosis.

  Next, a twelfth embodiment will be described. The configuration of the failure diagnosis apparatus for the fuel cell 10 is shown in FIG. Hereinafter, a description will be given centering on differences from the first embodiment.

In addition to the temperature detection means 16, an electrolyte membrane moisture content estimation means 22 for estimating the moisture content of the electrolyte membrane 2 is provided. Depending on the fuel cell temperature T and the moisture content of the electrolyte membrane 2 epsilon, changing the decision value Cj _i.

  Here, the amount of gas movement due to dissolution and diffusion changes according to the moisture content ε of the electrolyte membrane 2. For example, when the hydrogen partial pressure difference between the anode 10a and the cathode 10c is made constant and the fuel cell temperature T is made constant, the amount of fuel gas dissolved and diffused from the anode 10a to the cathode 10c is as shown in FIG. That is, as the moisture content ε of the electrolyte membrane 2 increases, the amount of fuel gas dissolved and transferred increases.

Therefore, in addition to the fuel cell temperature T to set the determination value Cj _i in accordance with the water content of the electrolyte membrane 2 epsilon. A failure of the fuel cell 10 is diagnosed by comparing the judgment value Cj _i with the voltage change amount ΔV _i when the reaction gas supply amount Q is changed.

  The failure diagnosis control of the fuel cell 10 will be described using the flowchart of FIG.

In step S7-2, in addition to the detection of the fuel cell temperature T, the moisture content ε of the electrolyte membrane 2 is estimated. In step S8-2, a judgment value Cj _i, is set according to the fuel cell temperature T and the moisture content epsilon. Others are the same as those in the first embodiment.

Thus, by changing the determination value Cj _i in accordance with the water content epsilon, further it is possible to consider the exact solution-diffusion movement, it is possible to further improve the diagnostic avoid erroneous increase failure diagnostic capabilities .

In this case, although by changing the decision values Cj _i in accordance with the fuel cell temperature T and the moisture content epsilon, not limited. For example, in a case where the fuel cell temperature T is maintained constant, may change the determination value Cj _i in accordance with only the moisture content epsilon. Furthermore, in this embodiment, in the first embodiment, although by changing the decision values Cj _i in accordance with the moisture content epsilon, also in the embodiment of the 2 to 11, depending on the water content epsilon The judgment value Cj can be changed.

  Next, the effect of this embodiment will be described. Only the effects different from those of the first embodiment will be described below.

A fuel cell 10 in which at least one unit cell 1 having an electrolyte membrane 2 sandwiched between an anode 10a and a cathode 10c is laminated, and a temperature detecting means 16 for detecting the temperature of the fuel cell 10, or an electrolyte membrane At least one of moisture content estimation means 22 for detecting or estimating the moisture content of 2. The temperature detecting means 16, or a determination value setting means for setting a judgment value Cj _i in accordance with the output of the water content estimating means 22 (S8-2), the failure diagnosis of the fuel cell 10 by using the diagnostic value Cj _i The diagnostic means (S9) which performs is provided. Thus, solution-diffusion movement varies in accordance with the water content of the temperature T and the electrolyte membrane 2 epsilon of the fuel cell 10, by changing the determination value Cj _i in accordance with the fuel cell temperature T and the moisture content epsilon Furthermore, it is possible to improve both the fault diagnosis capability and avoid misdiagnosis.

  The present invention is not limited to the best mode for carrying out the invention, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims. Absent.

  The present invention can be applied to a fuel cell failure diagnosis apparatus. In particular, the present invention can be applied to a failure diagnosis apparatus that diagnoses whether or not a reaction gas leaks due to a defect in a solid polymer film or the like.

It is a schematic block diagram of the failure diagnosis apparatus of the fuel cell used for 1st Embodiment. It is a figure which shows the gas transfer amount by melt | dissolution diffusion transfer with respect to fuel cell temperature. It is a control flowchart of the failure diagnosis in 1st Embodiment. It is a figure which shows the battery voltage with respect to oxidant gas flow volume. It is a figure which shows the judgment value with respect to the fuel cell temperature in 1st Embodiment. It is a control flowchart of the failure diagnosis in 2nd Embodiment. It is a schematic block diagram of the failure diagnosis apparatus of the fuel cell used for 3rd Embodiment. It is a control flowchart of the failure diagnosis in 3rd Embodiment. It is a figure which shows the battery voltage with respect to the gas pressure difference between electrodes. It is a figure which shows the judgment value with respect to the fuel cell temperature in 3rd Embodiment. It is a control flowchart of the failure diagnosis in 4th Embodiment. It is a control flowchart of the failure diagnosis in 5th Embodiment. It is a control flowchart of the failure diagnosis in 6th Embodiment. It is a figure which shows the judgment value with respect to the fuel cell temperature in 6th, 8th embodiment. It is a control flowchart of the failure diagnosis in 7th Embodiment. It is a figure which shows the judgment value with respect to the fuel cell temperature in 7th, 9th embodiment. It is a control flowchart of the failure diagnosis in 8th Embodiment. It is a control flowchart of the failure diagnosis in 9th Embodiment. It is a schematic block diagram of the failure diagnosis apparatus of the fuel cell used for 10th Embodiment. It is a control flowchart of the failure diagnosis in 10th Embodiment. It is a figure which shows the judgment value with respect to the fuel cell temperature in 10th Embodiment. It is a control flowchart of the failure diagnosis in 11th Embodiment. It is a figure which shows the judgment value with respect to the fuel cell temperature in 11th Embodiment. It is a schematic block diagram of the failure diagnosis apparatus of the fuel cell used for 12th Embodiment. It is a figure which shows the gas transfer amount by melt | dissolution diffusion transfer with respect to electrolyte membrane water content. It is a control flowchart of the failure diagnosis in 12th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Unit cell 2 Electrolyte membrane 10 Fuel cell 10a Anode 10c Cathode 12 Fuel gas flow rate control means 14 Oxidant gas flow rate control means 15 Voltage detection means 16 Temperature detection means 17 Fuel gas pressure control means 18 Oxidant gas pressure control means 19 Fuel electrode Blocking means 20 Fuel gas pressure detection means 21 Fault diagnosis control means 22 Moisture content estimation means

Claims (13)

A fuel cell in which at least one unit cell in which an electrolyte membrane is sandwiched between an anode and a cathode is laminated; and
At least one of temperature detecting means for detecting the temperature of the fuel cell, or moisture content detecting means for detecting or estimating the moisture content of the electrolyte membrane;
A judgment value setting means for setting a judgment value which is a threshold value for performing failure diagnosis of the fuel cell according to an output of the temperature detection means or the moisture content detection means;
A fuel cell failure diagnosis apparatus, comprising: a diagnosis unit configured to perform a failure diagnosis of the fuel cell using the determination value. At least a voltage detection unit that detects a battery voltage of each unit cell or each assembled battery in which a plurality of unit cells are connected in series, or a pressure detection unit that detects a fuel gas pressure in the fuel cell. With one side,
The determination value setting means sets a determination value of the voltage state or fuel gas pressure state of the fuel cell,
2. The fuel according to claim 1, wherein the diagnosis unit performs failure diagnosis by comparing the determination value with a voltage state or a fuel gas pressure state of the fuel cell obtained from the voltage detection unit or the pressure detection unit. Battery fault diagnosis device. Voltage detection means for detecting a battery voltage for each unit battery or for each assembled battery in which a plurality of the unit batteries are connected in series;
Reactive gas flow rate adjusting means for adjusting the reactive gas flow rate supplied to the fuel cell,
The determination value setting means sets a determination value of a voltage change amount when the flow rate of the reaction gas is changed from a predetermined first flow rate value to a second flow rate value,
2. The fuel cell failure diagnosis apparatus according to claim 1, wherein the diagnosis unit performs failure diagnosis by comparing a detected value of a voltage change amount when the reaction gas flow rate is changed with the determination value.   4. The fuel cell failure diagnosis device according to claim 3, wherein a voltage is detected by the voltage detection means after a predetermined time has elapsed since the reaction gas flow rate was changed. Voltage detection means for detecting a battery voltage for each unit battery or for each assembled battery in which a plurality of the unit batteries are connected in series;
Gas differential pressure adjusting means for adjusting the gas differential pressure of the anode and the cathode,
The determination value setting means sets a determination value of a voltage change amount when the gas differential pressure is changed from a predetermined first differential pressure value to a second differential pressure value,
2. The fuel cell failure diagnosis device according to claim 1, wherein the diagnosis unit performs failure diagnosis by comparing a detected value of a voltage change amount when the gas differential pressure is changed with the determination value.   The fuel cell failure diagnosis device according to claim 5, wherein the gas differential pressure is changed in a state where supply of the oxidant gas introduced to the cathode is stopped at the time of failure diagnosis.   7. The fuel cell failure diagnosis device according to claim 5, wherein a voltage is detected by the voltage detection unit after a predetermined time has elapsed since the gas differential pressure was changed. Voltage detection means for detecting a battery voltage for each unit battery or for each assembled battery in which a plurality of the unit batteries are connected in series;
Pressure adjusting means for adjusting the pressure of the anode,
The judgment value setting means sets the anode to a pressure value higher than that of the cathode, sets the judgment value of the voltage detection means after a predetermined time after stopping the supply of the oxidant gas to the cathode. ,
The diagnostic means sets the anode to a pressure value higher than that of the cathode, stops the supply of the oxidant gas to the cathode, and detects the detected value of the voltage detecting means after a predetermined time and the judgment value. The fuel cell failure diagnosis device according to claim 1, wherein failure diagnosis is performed by comparing Voltage detection means for detecting a battery voltage for each unit battery or for each assembled battery in which a plurality of the unit batteries are connected in series;
Pressure adjusting means for adjusting the pressure of the anode,
The judgment value setting means sets a judgment value of a time required for the anode to be set to a pressure value higher than that of the cathode and to be reduced to a predetermined voltage after the supply of the oxidant gas to the cathode is stopped. And
The diagnostic means sets the anode to a pressure value higher than that of the cathode, stops supplying the oxidant gas to the cathode, and then the detection value of the voltage detection means decreases to the predetermined voltage. The fuel cell failure diagnosis apparatus according to claim 1, wherein failure diagnosis is performed by comparing time and the determination value. Voltage detection means for detecting a battery voltage for each unit battery or for each assembled battery in which a plurality of the unit batteries are connected in series;
Pressure adjusting means for adjusting the pressure of the cathode,
The judgment value setting means sets the cathode to a pressure value higher than the anode, sets the judgment value of the voltage detection means after a predetermined time after stopping the supply of fuel gas to the anode,
The diagnostic means sets the cathode to a pressure value higher than that of the anode, stops the supply of fuel gas to the anode, and detects the detected value of the voltage detecting means after a predetermined time, and the judgment value. The fuel cell failure diagnosis apparatus according to claim 1, wherein failure diagnosis is performed by comparing the two. Voltage detection means for detecting a battery voltage for each unit battery or for each assembled battery in which a plurality of the unit batteries are connected in series;
Pressure adjusting means for adjusting the pressure of the cathode,
The judgment value setting means sets the cathode to a pressure higher than that of the anode, sets a judgment value of a time required to decrease to a predetermined voltage after stopping the supply of fuel gas to the anode,
The diagnostic means sets the cathode to a pressure value higher than that of the anode, stops supplying fuel gas to the anode, and waits until the detection value of the voltage detection means drops to the predetermined voltage. 2. The fuel cell failure diagnosis apparatus according to claim 1, wherein failure diagnosis is performed by comparing the determination value with the determination value. Pressure detecting means for detecting fuel gas pressure in the fuel cell;
Pressure adjusting means for adjusting the pressure of the anode;
Anode closing means for closing the anode, and
The judgment value setting means closes the anode in a state of setting a pressure value higher than that of the cathode, and sets a judgment value of the gas pressure value of the anode after a predetermined time has passed.
The diagnostic means closes the anode with a pressure value higher than that of the cathode, and performs a fault diagnosis by comparing the detected value of the anode pressure after a predetermined time with the judgment value. Item 8. The fuel cell failure diagnosis device according to Item 1. Pressure detecting means for detecting fuel gas pressure in the fuel cell;
Pressure adjusting means for adjusting the pressure of the anode;
Anode closing means for closing the anode, and
The determination value setting means sets a determination value for a time from when the anode is closed in a state where the anode is set to a pressure value higher than that of the cathode until the anode pressure value decreases to a predetermined pressure value,
Further, a failure diagnosis is made by comparing the time until the anode pressure value decreases to a predetermined pressure value after the anode is closed in a state where the anode is set at a higher pressure value than the cathode, and the judgment value. The fuel cell failure diagnosis apparatus according to claim 1, further comprising:

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