JP4547603B2 - Fuel cell deterioration judgment device - Google Patents

Description

  The present invention relates to a deterioration determination device that determines deterioration of a fuel cell at an early stage.

  A fuel cell is a device that directly converts energy released along with an oxidation reaction into electric energy by oxidizing fuel by an electrochemical process. Generally, an electrolyte layer that holds an electrolyte is a porous material. Is sandwiched between a pair of electrodes (fuel electrode and oxidant electrode). And in order for a fuel cell to generate electric power, each reaction gas needs to be sufficiently supplied to the fuel electrode and the oxidant electrode.

  In this fuel cell, there is a possibility that a cross leak may occur when a defect or the like is generated in the electrolyte layer due to elapse of use time or the like. When this cross leak occurs, the hydrogen in the fuel gas and the oxygen in the oxidant gas are directly reacted and consumed, resulting in a shortage of fuel gas and oxidant gas for power generation. It becomes difficult to do. Further, there is a possibility that the fuel cell is deteriorated to shorten the life of the fuel cell.

Therefore, in order to specify the occurrence of cross leak, for example, a hydrogen-containing gas containing a constant concentration of hydrogen is supplied to the fuel electrode of the fuel cell, and an oxygen-containing gas containing a constant concentration of oxygen is supplied to the oxidizer electrode. Record the correspondence between the change in the supply amount of the oxygen-containing gas over time and the change in the voltage generated in the fuel cell stack with the change, and the occurrence of the stack accompanying the change in the supply amount of the oxygen-containing gas. When the voltage changes suddenly, it is detected that hydrogen leakage has occurred in the stack, and the hydrogen leakage in the stack is determined from the correspondence of the change over time between the supply amount of oxygen-containing gas and the voltage generated in the stack. A diagnosis method for calculating the amount of cross leak when the amount of hydrogen leakage is equal to or greater than the amount of hydrogen leakage when the stack is normal is introduced. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 9-27336

  The cross leak includes an electrolyte membrane and an electrode (fuel electrode; anode) composed of a catalyst layer disposed on one surface of the electrolyte membrane and an electrode (oxidant electrode; composed of a catalyst layer disposed on the other surface of the electrolyte membrane. A cathode-) membrane-electrode assembly (MEA: Membrane-Electrode Assembly: hereinafter simply referred to as “MEA”) has a minute hole, and the anode gas flows into the cathode gas flow path. On the other hand, since the anode gas and the cathode gas burn directly without generating electricity, it is thought that the MEA is accelerated in thermal degradation, but this cross leak amount increases rapidly when the deterioration of the fuel cell starts. . For this reason, even if the occurrence of the cross leak is specified (detected) by the conventional diagnostic method, the fuel cell may have already deteriorated at the specified time.

  An object of the present invention is to solve such a conventional problem, and it is possible to determine the deterioration of the fuel cell that can diagnose the progress of the deterioration of the fuel cell before the cross leak occurs. An object is to provide an apparatus.

To this end, the present invention is to provide a provided in the cathode gas outlet passage of the fuel cell is eluted from the MEA of the fuel cell that is contained in the product water discharged through the cathode gas outlet passage comprising a detection means for detecting the total amount of the specific component, wherein the sensing means comprises a material that travels corrosion by the presence of the specific component, determining deterioration determination device degradation of the fuel cell from corrosion progress of the substance It is to provide.

The deterioration determination device having this configuration detects deterioration of the fuel cell by detecting the total amount of specific components eluted from the MEA of the fuel cell contained in the fluid discharged from the cathode gas outlet passage of the fuel cell. Since the determination can be made, it is possible to grasp the progress of deterioration of the fuel cell before the cross leak occurs.

  The detection means may include a substance that is corroded by a specific component contained in the fluid.

  According to this configuration, it is possible to grasp the progress of deterioration of the fuel cell according to the corrosion state of the substance. Specifically, the specific component is a component that elutes from the MEA with the progress of deterioration of the fuel cell and is discharged from the fuel cell through the cathode gas outlet passage, and the discharge time of the specific component This indicates that the longer the is, that is, the greater the total passing amount of the specific component is, the more the deterioration of the fuel cell is progressing. Moreover, the corrosion of the substance corroded based on the amount of the specific component progresses as the time of exposure to the specific component increases. Therefore, the progress of deterioration of the fuel cell can be grasped according to the corrosion state of this substance.

  The deterioration determination apparatus according to the present invention further includes a window through which the corrosion state of the substance can be visually observed, and the deterioration of the fuel cell can be determined by observing the corrosion state of the substance through the window. .

Further, the deterioration determination apparatus according to the present invention includes an imaging means for imaging the corrosion state of the substance, and a notification for notifying the deterioration state of the fuel cell from the degree of corrosion progress of the substance determined from the data output from the imaging means. And means.

The detection means further includes a housing that communicates with the cathode gas outlet passage and allows the generated water to pass therethrough, and a recess that is formed in the housing and is at least partially colored. The substance may have a structure embedded in the recess so as to be exposed to the generated water .

  If comprised in this way, when the said substance is corroded and it elutes from a recessed part, the colored part of a recessed part will be exposed and it will be easier to observe the corrosion state of the substance from the said window. it can. In addition, it is possible to notify the deterioration state of the fuel cell on the condition that the colored portion has been photographed by the imaging means.

Further, in the deterioration determination apparatus according to the present invention, the detection means detects an electric resistance measurement means for measuring the electric resistance of the substance, and indicates a deterioration state of the fuel cell by increasing the resistance value measured by the electric resistance measurement means. And a notification means for notification. Specifically, the corrosion of the substance progresses as the time of exposure to the specific component increases, and the volume (cross-sectional area) gradually decreases. The smaller the area, the larger. Therefore, the deterioration state of the fuel cell can be determined based on the measurement value measured by the electric resistance measurement means.

  The method for measuring the electrical resistance of the substance is not particularly limited. For example, various methods such as obtaining from the relationship between the voltage and current applied to the substance and using a Wheatstone bridge are employed. can do.

In the deterioration determination apparatus according to the present invention, when the detection unit adds an elution amount of the substance to the generated water, and the elution amount calculated by the addition unit exceeds a predetermined amount. And a notification means for notifying the deterioration state of the fuel cell.

  The substance may contain a corrosive component such as aluminum. The specific component can contain fluorine. Moreover, the component of the substance currently used as a catalyst of fuel cells, such as platinum, may be sufficient. Further, the specific component may be present in advance by separately kneading a predetermined component into any of the constituent materials of the MEA.

  The amount of the specific component referred to in the present invention may be, for example, a parameter that can indirectly estimate (detect) the elution amount of the specific component or the elution amount of the specific component. Examples of the parameter include various parameters such as the presence / absence of a specific component in the fluid and the concentration and ratio of the specific component in the fluid.

  The deterioration determination apparatus according to the present invention includes a detection unit that detects the amount of a specific component contained in a fluid discharged through a cathode gas outlet passage of a fuel cell, and is based on data output from the detection unit. In order to determine the deterioration of the fuel cell, the progress of the deterioration of the fuel cell can be grasped before the cross leak occurs, and the deterioration of the fuel cell can be detected at an early stage.

  Next, a fuel cell deterioration determination device according to a preferred embodiment of the present invention will be described with reference to the drawings.

  In addition, the Example described below is the illustration for demonstrating this invention, and this invention is not limited only to these embodiment. Therefore, the present invention can be implemented in various forms without departing from the gist thereof.

  FIG. 1 is a schematic diagram of a fuel cell provided with a deterioration determining apparatus according to a first embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II shown in FIG.

  As shown in FIG. 1, a fuel cell 100 to which a deterioration determination device 1 according to a first embodiment is connected includes a fuel cell main body 101 including a stack including a plurality of cells in which MEAs and separators are superimposed, An anode gas inlet passage 102 that supplies anode gas (hydrogen gas) to a fuel electrode (anode) that is connected to the battery body 101 and is a component of the MEA, and air that is connected to the fuel cell body 101 and is a component of the MEA A cathode gas inlet passage 103 for supplying cathode gas (air) to the electrode (cathode), an anode gas outlet passage 104 connected to the fuel cell main body 101 for discharging the anode gas, and a generated water connected to the fuel cell main body 101 And a cathode gas outlet passage 105 for discharging the cathode gas.

  The produced water discharged from the cathode gas outlet passage 105 contains a specific component (fluorine component in the first embodiment) eluted from the material constituting the MEA as the power generation time of the fuel cell 100 elapses. It comes to be contained. That is, this specific component is a component that is discharged from the fuel cell main body 101 through the cathode gas outlet passage 105 as the MEA deteriorates, and the longer the discharge time is, the more the specific component is eluted. The amount increases, indicating that the deterioration of the fuel cell body 101 is progressing.

  The deterioration determination device 1 is provided in the cathode gas outlet passage 105 of the fuel cell 100 and detects a specific component contained in the generated water passing therethrough. The deterioration determination device 1 includes a detection unit 10 that detects the amount of the specific component contained in the generated water discharged through the cathode gas outlet passage 105. The detection means 10 is formed between the cathode gas outlet passage 105 and the cathode gas outlet passage 105 so as to communicate with the cathode gas outlet passage 105 and allow the product water to pass therethrough, and the wall portion 14 defining the housing 11. A recess 12 that is colored at least in part and a substance 13 embedded in the recess 12 are provided.

  An observation window 15 capable of observing the state of the substance 13 from the outside is formed at a position facing the recess 12 of the housing 11.

  As shown in FIG. 2 in particular, the recess 12 is formed in a step shape in the wall portion 14 of the housing 11 so that the depth thereof is three steps. The step portion 16 that defines the shallowest depth of the recess 12 is colored with a desired color such as red.

  The substance 13 is mainly composed of aluminum, corroded by a fluorine component as a specific component contained in the generated water, eluted into the generated water, and discharged to the outside. That is, the corrosion of the substance (aluminum) 13 progresses as the time of exposure to the generated water containing the specific component (fluorine component) is longer, that is, as the total amount of the specific component eluted in the generated water is larger. To do. Therefore, the corrosion state of the substance 13 depends on the amount (total amount) of the specific components eluted in the generated water, so that the corrosion state of the substance 13 is observed through the observation window 15. Thus, the amount of the specific component is detected, whereby the progress of deterioration of the fuel cell main body 101 can be grasped. Hereinafter, a specific operation of the deterioration determination apparatus 1 according to the first embodiment will be described.

  First, in order to generate electric power with the fuel cell 100, anode gas is supplied from the anode gas inlet passage 102 to the fuel cell main body 101 and cathode gas is supplied from the cathode gas inlet passage 103 to the fuel cell main body 101. Is converted to hydrogen ions and electrons, and the hydrogen ions move to the cathode side in the electrolyte membrane which is a constituent element of MEA. On the other hand, a reaction for generating water from oxygen, hydrogen ions, and electrons is performed on the cathode side. The generated water (generated water) reaches the cathode gas outlet passage 105. As the power generation time of the fuel cell 100 elapses, the generated water contains a fluorine component as a specific component eluted from the material constituting the MEA as described above.

  Next, the generated water that has reached the cathode gas outlet passage 105 passes through the housing 11 of the deterioration determination device 1. At this time, aluminum, which is a substance 13 corroded by the fluorine component, is embedded in the recess 12 formed in the wall portion 14 of the housing 11, and this aluminum ( Substance 13) will be exposed to the product water containing the fluorine component.

  When the substance 13 is exposed to generated water containing a fluorine component, the substance 13 is gradually corroded by the fluorine component in the generated water, and is eluted into the generated water and gradually decreases. This state is observed from the outside through the observation window 15. This observation may be performed visually by the user on a regular basis, or may be performed by periodically taking a photograph (image data) with an imaging device such as a camera through the observation window 15. May be monitored at any time by an imaging device such as a video camera. Such observation is continued. For example, when a colored color can be seen in the step 16 of the recess 12, it is determined that the fuel cell main body 101 has deteriorated (it has reached the end of its life), and is replaced with a new fuel cell 100. .

  Whether or not the fuel cell body 101 has deteriorated (has reached the end of its life) can be determined arbitrarily from the correlation between the life of the fuel cell 100 and the corrosion state of the substance 13 caused by the produced water containing the specific component. Can be determined.

  Here, when the corrosion state of the substance 13 is observed by an imaging device such as a camera or a video camera instead of being visually observed by the user, the image data output from the imaging device is recognized and derived from the correlation. The comparison means for comparing the reference data with the image data, and the comparison by the comparison means determined that the image data exceeded the reference data (for example, coloring of the step portion 16 appeared). At this time, it may further comprise notification means for determining that the fuel cell 100 has deteriorated and notifying it. In this way, it is possible to know whether or not the fuel cell 100 has deteriorated (has reached the end of its life) by the notification means without directly performing the observation by the user. As the notification means, various forms such as notification by sound, notification by image, notification by vibration, and the like can be adopted. As a specific example, for example, when determining deterioration of a fuel cell mounted on an automobile, an instrument for notifying the deterioration state of the fuel cell at a predetermined position on the instrument panel, a display board for notifying deterioration, etc. Alternatively, an alarm or music may be sounded.

  The imaging device may be disposed in the housing 11 as desired. In this case, a waterproof and corrosion-resistant imaging device is used so that the imaging device is not immersed in the generated water containing the specific component, or the imaging device has a specific component in the housing 11. It is desirable to consider, for example, forming an accommodating portion that is accommodated without touching the produced water containing the.

  Next, a fuel cell deterioration determination apparatus according to a second embodiment of the present invention will be described with reference to the drawings.

  FIG. 3 is a schematic diagram illustrating a fuel cell deterioration determination apparatus according to a second embodiment. In the second embodiment, the same members as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, the main difference between the degradation determination device 2 according to the second embodiment and the degradation determination device 1 according to the first embodiment is that the resistance of the substance 13 corroded by the generated water containing the specific component. And determining deterioration of the fuel cell 100 based on the resistance value.

  That is, as shown in FIG. 3, the deterioration determination device 2 according to the second embodiment is provided in the cathode gas outlet passage 105 of the fuel cell 100 described in the first embodiment, and is contained in the generated water passing therethrough. It detects the amount of a specific component. The deterioration determination device 2 includes detection means 20 that detects the amount of the specific component contained in the generated water discharged through the cathode gas outlet passage 105. The detection means 20 is interposed between the cathode gas outlet passage 105 and communicates with the cathode gas outlet passage 105 to allow the generated water to pass therethrough, and a recess 19 formed in the wall portion 14 defining the housing 21. And a substance 13 embedded in the recess 19 and a resistance measuring device 22 for measuring the resistance of the substance 13. In Example 2, the housing 21 is made of a material that is an insulator substance and is resistant to generated water containing a specific component.

  The resistance measuring device 22 can employ various methods such as obtaining from the relationship between the voltage and current applied to the substance 13 or using a Wheatstone bridge. The resistance measuring device 22 is connected to a determination means 23 for determining whether or not the resistance value acquired from the resistance measuring device 22 exceeds a predetermined threshold value set in advance. Further, the determination means 23 is connected to a notification means 24 for notifying when the resistance value acquired from the resistance measuring device 22 by the determination means 23 exceeds a predetermined threshold value set in advance.

  In the deterioration determination device 2 having this configuration, the housing 21 contains generated water (containing a fluorine component eluted from a material constituting the MEA as a specific component) that has reached from the cathode gas outlet passage 105 of the fuel cell 100. When passing through the inside, the substance 13 embedded in the recess 19 is exposed to the produced water containing the fluorine component as in the first embodiment. As a result, the substance 13 is gradually corroded by the fluorine component in the generated water and eluted into the generated water and gradually decreases. Here, as described above, the substance 13 is corroded as the time for which the substance 13 is exposed to the generated water containing the specific component (fluorine component) is longer, that is, as the total amount of the specific component eluted in the generated water is larger. Progresses. Therefore, since the corrosion state of the substance 13 depends on the amount (total amount) of the specific component eluted in the generated water, the amount of the specific component is detected based on the corrosion state of the substance 13.

  As the substance 13 decreases, the resistance value measured by the resistance measuring instrument 22 connected to the substance 13 increases. The data (resistance value) acquired by the resistance measuring device 22 is output to the determination unit 23, and the determination unit 23 determines whether or not the acquired data exceeds a predetermined threshold value set in advance. When the determination unit 23 determines that the data has exceeded the threshold, the notification unit 24 notifies the data. When this notification is made, it is determined that the fuel cell main body 101 has deteriorated (it has reached the end of its life), and is replaced with a new fuel cell 100.

  Next, a fuel cell deterioration determination apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings.

  FIG. 4 is a schematic diagram illustrating a fuel cell deterioration determination apparatus according to a third embodiment. In the third embodiment, the same members as those described in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the main differences between the degradation determination device 3 according to the third embodiment and the degradation determination devices 1 and 2 according to the first and second embodiments are based on the generated water containing the specific component. The amount of elution of the corroded substance 13 into the produced water is measured, and the deterioration of the fuel cell 100 is determined based on this amount of elution.

  That is, the deterioration determination device 3 according to the third embodiment is provided in the cathode gas outlet passage 105 of the fuel cell 100 described in the first embodiment, as shown in FIG. The deterioration determination device 3 includes detection means 30 that detects the amount of the specific component contained in the generated water discharged through the cathode gas outlet passage 105. This detecting means 30 measures and adds the amount of elution of the substance 13 into the generated water of the housing 21, the recessed part 19 formed in the wall part 14 defining the housing 21, the substance 13 embedded in the recessed part 19 And an adding device 32 (accumulating).

  The adding device 32 measures, for example, the amount of the substance 13 (for example, aluminum ions) in the produced water and the concentration of the substance 13 with respect to the produced water, and these values and a preset unit time of the produced water per unit time. The elution amount of the substance 13 into the product water is calculated from the passing amount. Here, as described above, the longer the time period for which the substance 13 is exposed to the produced water containing the specific component (fluorine component), that is, the greater the total amount of the specific component eluted in the produced water, Elutes in product water. Therefore, the amount of the specific component is detected by calculating the elution amount of the substance 13.

  The adder 32 is connected to a determination means 33 for determining whether or not the value acquired from the adder 32 exceeds a predetermined threshold value set in advance. Further, the determination means 33 is connected to a notification means 34 that notifies when the value acquired from the adding device 32 by the determination means 33 exceeds a predetermined threshold value set in advance.

  In the deterioration determination device 3 having this configuration, the housing 21 contains generated water (containing a fluorine component eluted from the material constituting the MEA as a specific component) that has reached from the cathode gas outlet passage 105 of the fuel cell 100. When passing through the inside, the substance 13 embedded in the recess 19 is exposed to generated water containing a fluorine component. Thereby, the substance 13 is gradually corroded by the fluorine component in the generated water and is eluted in the generated water. Then, this elution amount is accumulated with the elapsed time by the adding device 32, and this accumulated data is output to the determination means 33. The determination means 33 determines whether or not the acquired data exceeds a predetermined threshold value set in advance. When the determination unit 33 determines that the data has exceeded the threshold, the notification unit 34 notifies the data. When this notification is made, it is determined that the fuel cell main body 101 has deteriorated (it has reached the end of its life), and is replaced with a new fuel cell 100.

  In addition, in Example 3, although the degradation determination apparatus 3 provided with the addition apparatus 32 which calculates the elution amount of the substance 13 eluted in production | generation water with elapsed time was demonstrated, it is not restricted to this, For example, in production | generation water You may provide the addition apparatus which adds (accumulates) the quantity of the specific component contained with elapsed time.

  Further, in Example 3, the case where the specific component contained in the generated water is fluorine has been described. However, the present invention is not limited thereto, and is a material that constitutes the MEA, and is a component that elutes into the generated water, for example, platinum. The component of the substance currently used as a catalyst of a fuel cell etc. may be sufficient. Furthermore, the specific component may be previously present by, for example, separately kneading a predetermined component (for example, copper or gold) into any of the constituent materials of the MEA.

  In the first to third embodiments, the case where the detection unit 10 (20, 30) is provided in the cathode gas outlet passage 105 has been described. However, the detection unit 10 (20, 30) is not limited to the anode gas outlet. It may be provided in the passage 104.

  Moreover, although Example 1-3 demonstrated aluminum as an example as the substance 13, not only this but the substance 13 will be another substance if it will corrode by the specific component contained in produced | generated water. Of course, it may be.

  In the first to third embodiments, the detection unit is provided with the housing 11 (21) that communicates with the cathode gas outlet passage 105 and allows the generated water to pass therethrough, and the substance 13 is embedded in the recess 12 (19). Although it demonstrated, not only this but the detection means does not need to be provided with the housing separately, as long as it is provided in the cathode gas outlet channel or the anode gas outlet channel. Specifically, for example, the substance 13 may be placed directly at a desired position in the cathode gas outlet passage 105 or the anode gas outlet passage 104.

  Furthermore, in the first to third embodiments, the case where the generated water is used as the fluid has been described. However, the present invention is not limited to this, and the fluid is both the cathode gas and the generated water exhausted from the cathode gas outlet passage 105. In some cases, only the cathode gas may be used. Alternatively, the anode gas exhausted from the anode gas outlet passage 104 may be used.

It is a schematic diagram of the fuel cell provided with the deterioration determination apparatus concerning Example 1 of this invention. It is sectional drawing along the II-II line | wire shown in FIG. It is a schematic diagram which shows the deterioration determination apparatus concerning Example 2 of this invention. It is a schematic diagram which shows the deterioration determination apparatus concerning Example 3 of this invention.

Explanation of symbols

1, 2, 3 Deterioration determination device 10, 20, 30 Detection means 11, 21 Housing 12, 19 Recess 13 Material 15 Observation window 16 Step 22 Resistance measuring device 23, 33 Determination means 24, 43 Notification means 100 Fuel cell 101 Fuel Battery body 105 Cathode gas outlet passage

Claims (8)

A detecting means provided in the cathode gas outlet passage of the fuel cell and detecting a total amount of specific components eluted from the MEA of the fuel cell contained in the generated water discharged through the cathode gas outlet passage;
The detection unit is a deterioration determination device that includes a substance that progresses corrosion due to the presence of the specific component, and that determines deterioration of the fuel cell from the degree of progress of the corrosion of the substance.   The deterioration determination apparatus according to claim 1, further comprising: a window through which the corrosion state of the substance can be visually observed, and determining deterioration of the fuel cell by observing the corrosion state of the substance through the window.   The imaging means for imaging the corrosion state of the substance, and a notification means for notifying the deterioration state of the fuel cell from the degree of progress of corrosion of the substance determined from data output from the imaging means. Degradation judgment device.   The detection means further includes a housing that communicates with the cathode gas outlet passage and allows the generated water to pass therethrough, and a concave portion that is formed in the housing and is colored at least partially. The deterioration determination device according to any one of claims 1 to 3, wherein the deterioration determination device is embedded in the recess so as to be exposed to the generated water.   2. The deterioration according to claim 1, further comprising: an electric resistance measuring unit that measures an electric resistance of the substance; and a notification unit that notifies a deterioration state of the fuel cell by an increase in a resistance value measured by the electric resistance measuring unit. Judgment device.   Adding means for adding the elution amount of the substance to the generated water; and notifying means for notifying the deterioration state of the fuel cell when the elution amount calculated by the adding means exceeds a predetermined amount. The deterioration determination apparatus according to claim 1. The degradation determination apparatus according to any one of claims 1 to 6 , wherein the substance contains aluminum. The deterioration determination device according to any one of claims 1 to 7 , wherein the specific component contains fluorine.

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