JP2008218284A - Deterioration decision device for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of accurately deciding the deterioration of a fuel cell. <P>SOLUTION: A box 60 for confirming the deterioration environment of a hydrocarbon system electrolyte membrane as a simulation unit imitating an electrolyte membrane 11 of a fuel cell 10 is installed in the vicinity of an inlet of an oxidizing gas exhausting passage 54. An electrolyte membrane for confirmation of the same kind as the hydrocarbon system electrolyte membrane used in the fuel cell 10 and a window for confirming the color of the electrolyte membrane for confirmation by visual inspection are installed in the box 60 for confirming. A worker can decide the degree of deterioration of the electrolyte membrane 11 from the color by observing the color of the electrolyte membrane 61 for confirmation by looking in at the window 69 for confirmation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell deterioration determination device that determines deterioration of a fuel cell including a hydrocarbon-based electrolyte membrane.

  In a fuel cell, the electrolyte membrane deteriorates with the passage of time of use. If the decrease in output or efficiency due to the deterioration of the electrolyte membrane is unacceptable, the fuel cell main body is replaced as the life of the fuel cell. In order to know the life of the fuel cell, an apparatus for determining the degree of deterioration of the electrolyte membrane of the fuel cell has been proposed. For example, as shown in Patent Document 1, there is a device that determines the deterioration of a fuel cell by measuring the impedance of a fuel cell and matching the measured impedance against a database that shows a change in impedance prepared in advance.

JP 2006-24437 A

  However, the conventional technique has a problem that it is difficult to determine the degree of deterioration of the fuel cell with high accuracy. In a fuel cell that has been put to practical use, the electrolyte membrane has a large area, but the distribution of produced water varies greatly depending on the position of the electrolyte membrane. On the other hand, since the impedance value varies greatly depending on the generated water, the deterioration determination device that measures the impedance takes various impedance values at the measurement position, and the degree of deterioration is accurately determined from these values. It was difficult to judge.

  The present invention has been made in view of the above points, and it is an object of the present invention to accurately determine the deterioration of a fuel cell.

In order to solve the above problems, a first fuel cell deterioration determination device of the present invention provides:
In a fuel cell deterioration determination device that includes a hydrocarbon-based electrolyte membrane and determines deterioration of a fuel cell that generates power by supplying hydrogen-containing fuel gas to the anode electrode and oxygen-containing oxidizing gas to the cathode electrode,
It is provided near the entrance of the cathode offgas passage through which the cathode offgas discharged from the cathode electrode flows, and the confirmation electrolyte membrane of the same type as the electrolyte membrane provided in the fuel cell and the color of the confirmation electrolyte membrane can be visually observed And a confirmation box having a confirmation window.

  In the first fuel cell deterioration determination device having the above-described configuration, the confirmation box functions as a simulation unit that makes the deterioration environment of the hydrocarbon-based electrolyte membrane resemble the electrolyte membrane of the fuel cell. That is, since the confirmation box is provided near the entrance of the cathode off-gas passage, the deterioration environment of the confirmation electrolyte membrane provided in the confirmation box is the following (i), the electrolyte membrane provided in the fuel cell, It will be very similar in (ii).

(I) Since the installation location of the confirmation box is close to the fuel cell, the confirmation electrolyte membrane is kept substantially the same temperature as the electrolyte membrane of the fuel cell.
(Ii) The number of radicals generated at the electrode is large on the cathode side, and moreover on the downstream side of the cathode channel in the fuel cell because it moves on the generated water. For this reason, the vicinity of the entrance of the cathode off-gas passage, where the confirmation box is installed, is kept substantially the same as the position where the number of radicals is the largest in the fuel cell.

  Therefore, in the first fuel cell deterioration determination device, the electrolyte membrane for confirmation deteriorates to the same extent as the electrolyte membrane provided in the fuel cell with the passage of time. In turn, when the hydrocarbon electrolyte membrane deteriorates, it changes to a dark color. In the first fuel cell deterioration determination device of the present invention, the operator can visually know the color of the electrolyte membrane provided in the fuel cell by visually checking the color of the electrolyte membrane for confirmation from the confirmation window. Can do. Therefore, the operator can determine the deterioration of the electrolyte membrane provided in the fuel cell with high accuracy from the color that the operator can know.

  In the first fuel cell deterioration determination apparatus, the confirmation box may include a frame that sandwiches the periphery of the confirmation electrolyte membrane. The fuel cell generally has a configuration in which the periphery of the electrolyte membrane is sandwiched between gas seal members. According to the above configuration, the method of holding the electrolyte membrane for confirmation is similar to the fuel cell. Can be. If the electrolyte membrane is repeatedly dried and wet with the surroundings sandwiched, the electrolyte membrane may swell and shrink, which may cause degradation. In terms of mechanical stress, the confirmation box is in the same degradation environment as the fuel cell. Can be kept in. For this reason, the electrolyte membrane for confirmation becomes a better representation of the color of the electrolyte membrane of the fuel cell, and the state of deterioration of the electrolyte membrane provided in the fuel cell can be determined with higher accuracy.

The second fuel cell deterioration determination device of the present invention is
In a fuel cell deterioration determination device that includes a hydrocarbon-based electrolyte membrane and determines deterioration of a fuel cell that generates power by supplying hydrogen-containing fuel gas to the anode electrode and oxygen-containing oxidizing gas to the cathode electrode,
An electrolyte membrane for confirmation of the same type as the electrolyte membrane provided in the fuel cell, provided upstream of the cathode offgas passage through which the cathode offgas discharged from the cathode electrode flows;
A colorimetric means for measuring the color of the electrolyte membrane for confirmation;
And determining means for determining the degree of deterioration of the electrolyte membrane provided in the fuel cell based on the measured color.

  In the second fuel cell deterioration determination device having the above-described configuration, the confirmation electrolyte membrane well represents the color of the electrolyte membrane of the fuel cell for the same reason as the first fuel cell deterioration determination device. ing. The color measurement means measures the color of the electrolyte membrane for confirmation, and the determination means determines the degree of deterioration of the electrolyte membrane provided in the fuel cell based on the measured color. Therefore, in the second fuel cell deterioration determination device, the deterioration of the electrolyte membrane provided in the fuel cell can be determined automatically and with high accuracy, not by human visual observation.

The third fuel cell deterioration determination device of the present invention is
In a fuel cell deterioration determination device that includes a hydrocarbon-based electrolyte membrane and determines deterioration of a fuel cell that generates power by supplying hydrogen-containing fuel gas to the anode electrode and oxygen-containing oxidizing gas to the cathode electrode,
A colorimetric means for measuring the color of the electrolyte membrane;
And determining means for determining the degree of deterioration of the electrolyte membrane provided in the fuel cell based on the measured color.

  In the third fuel cell deterioration determination device having the above configuration, the color of the confirmation electrolyte membrane is measured by the color measurement means, and the degree of deterioration of the electrolyte membrane is determined by the determination means based on the measured color. Since the color of the electrolyte membrane of the fuel cell changes depending on the degree of degradation of the electrolyte membrane, the degradation of the electrolyte membrane provided in the fuel cell can be determined with high accuracy based on the color of the electrolyte membrane.

  The fuel cell may have a configuration in which the cathode electrode has an uncovered portion of the cathode electrode in the vicinity of the downstream side of the oxidizing gas, and the color measurement unit is provided in the uncovered portion of the cathode electrode. As described above, the vicinity of the downstream side of the oxidizing gas is the position where the number of radicals moved in the generated water is the largest. According to the above configuration, the color of the electrolyte membrane at this position is measured, so that the most in the electrolyte membrane. It is possible to determine the state of deterioration of a portion where deterioration is severe with high accuracy.

  The second or third fuel cell deterioration determination device may further include an alarm unit that issues an alarm when the determination unit determines that the degree of deterioration is large. According to this configuration, the operator can be informed that the degree of the electrolyte membrane has increased.

Next, embodiments of the present invention will be described in the following order based on examples.
A. First embodiment:
A-1. Overall configuration of the fuel cell system:
A-2. Confirmation box configuration:
A-3. Deterioration determination work A-4. Action, effect:
B. Second embodiment:
C. Third embodiment:
D. Other embodiments:

A. First embodiment:
A-1. Overall configuration of the fuel cell system:
FIG. 1 is an overall configuration diagram of a fuel cell system 1 to which a first embodiment of the present invention is applied. As shown in the figure, the fuel cell system 1 includes a fuel cell 10 that generates power upon receiving a supply of a fuel gas containing hydrogen and an oxidizing gas containing oxygen, a fuel gas source 20 that stores the fuel gas, A fuel gas passage system 30 for circulating fuel gas, a blower 40 capable of supplying air as oxidizing gas, and an oxidizing gas passage system 50 for circulating oxidizing gas in the system are provided.

  The fuel cell 10 receives supply of fuel gas and oxidant gas, and causes an electrochemical reaction in the anode electrode and the cathode electrode according to the following reaction formula to generate electric power. That is, when the fuel gas is supplied to the anode electrode and the oxidizing gas is supplied to the cathode electrode, the reaction of equation (1) occurs on the anode electrode side, and the reaction of equation (2) occurs on the cathode electrode side. As for, reaction of Formula (3) is performed.

H ₂ → 2H ⁺ + 2e ⁻ (1)
2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O (2)
H ₂ + (1/2) O ₂ → H ₂ O (3)

  Specifically, the fuel cell 10 is configured by a fuel cell stack in which a plurality of single cells CL are stacked. FIG. 2 is an explanatory view showing a longitudinal section of the single cell CL. As shown in the figure, a single cell CL includes a membrane electrode assembly (hereinafter referred to as MEA) 14 in which an anode electrode 12 and a cathode electrode 13 are arranged on both surfaces of an electrolyte membrane 11, and a periphery of the MEA 14. The seal member 15 is provided, and a pair of separators 16 and 17 that are in close contact with the seal member 15 with the MEA 14 sandwiched from both sides. Concavities and convexities are formed on both surfaces of the separators 16 and 17 (in the drawing, one surface to show one cell), and the gas flow path in a single cell is interposed between the sandwiched anode electrode 12 and cathode electrode 13. 18 and 19 are formed. Among these, the fuel gas supplied as described above is supplied to the gas flow path 18 formed between the anode electrode 12 and the anode electrode 12. The oxidizing gas flows in each.

  The fuel cell 10 is a solid polymer fuel cell, and the electrolyte membrane 11 uses a hydrocarbon-based electrolyte membrane as a polymer material. The anode 12 and the cathode 13 are composed of a catalyst layer and a gas diffusion layer. The outer peripheral portion of the electrolyte membrane 11 of the MEA 14 is not provided with the anode electrode 12 or the cathode electrode 13 (catalyst layer and gas diffusion layer), and has a protruding configuration, and the entire periphery of the protruding portion is sealed. A member 15 is provided. The seal member 15 is molded from a fluorine-based rubber. By interposing between the MEA 14 and the separator 16 and between the MEA 14 and the separator 17, a space in which the fuel gas surrounded by the electrolyte membrane 11 and the separator 16 exists is present. Sealing and interposing between the MEA 14 and the separator 17 seals the space where the oxidizing gas surrounded by the electrolyte membrane 11 and the separator 17 exists.

  Returning to FIG. 1, the fuel gas passage system 30 includes a fuel gas supply passage 32 from the discharge port of the fuel gas source 20 to the supply port of the fuel cell 10, and a fuel gas discharge from the discharge port of the fuel cell 10 to the outside. And a use passage 34. The supply port and the discharge port of the fuel cell 10 are connected to a gas flow path 18 in the single cell (FIG. 2) formed between the anode 12.

  The oxidizing gas passage system 50 includes an oxidizing gas supply passage 52 that extends from the discharge port of the blower 40 to the supply port of the fuel cell 10, and an oxidizing gas discharge passage 54 that extends from the discharge port of the fuel cell 10 to the outside. The supply port and the discharge port of the fuel cell 10 are connected to a gas flow path 19 in the single cell formed between the cathode electrode 13 (FIG. 2). The oxidizing gas discharge passage 54 corresponds to a “cathode off-gas passage” in the present invention. A confirmation box 60 constituting the first fuel cell deterioration determination device of the present invention is provided in the vicinity of the inlet of the oxidizing gas discharge passage 54, that is, in the vicinity of the discharge port of the fuel cell 10. Although not shown, the fuel gas passage system 30 and the oxidizing gas passage system 50 are further provided with various auxiliary machines such as a pump as necessary.

A-2. Confirmation box configuration:
FIG. 3 is an exploded perspective view showing an exploded state of the confirmation box 60, and FIG. 4 is a cross-sectional view showing a longitudinal section of the confirmation box 60. As shown in both figures, the confirmation box 60 includes an electrolyte membrane (hereinafter referred to as a confirmation electrolyte membrane) 61, a pair of seal frames 62 and 63, a pair of upper lids 64, and a lower lid 65. The confirmation electrolyte membrane 61 is a membrane formed of the same polymer material as the electrolyte membrane 11 provided in the fuel cell 10. The seal frames 62 and 63 are rectangular frames, and sandwich the outer peripheral portion of the confirmation electrolyte membrane 61 from both sides. The seal frames 62 and 63 are formed from fluorine-based rubber in the same manner as the seal member 15 provided in the fuel cell 10. The upper lid 64 and the lower lid 65 are in close contact with the seal frames 62 and 63 in a state where the confirmation electrolyte membrane 61 sandwiched between the seal frames 62 and 63 is sandwiched from both sides. Bolt holes 64h and 65h are formed in the upper lid 64 and the lower lid 65, and the upper lid 64 and the lower lid 65 are fastened by bolts 66 that pass through the bolt holes 64h and 65h.

  As a result, the seal frames 62 and 63 are surrounded by the confirmation electrolyte membrane 61 and the upper lid 64 by being interposed between the confirmation electrolyte membrane 61 and the upper lid 64 and between the confirmation electrolyte membrane 61 and the lower lid 65. The space 67 and the space 68 surrounded by the confirmation electrolyte membrane 61 and the lower lid 65 are sealed. Both spaces 67 and 68 communicate with the oxidizing gas discharge passage 54 through a communication hole (not shown), and the oxidizing gas discharged from the cathode electrode 13, that is, the cathode off-gas flows therethrough.

  A confirmation window 69 is formed at the center of the upper lid 64. The confirmation window 69 is a rectangular through hole in which a portion of the confirmation electrolyte membrane 61 that is not in contact with the seal frames 62 and 63 can be visually observed, and is filled with a plate glass 69G. The plate glass 69G can be replaced with a transparent plastic plate.

A-3. Deterioration judgment work:
The operator performs a deterioration determination operation for determining the degree of deterioration of the electrolyte membrane 11 provided in the fuel cell 10 by using the confirmation box 60 provided on the upstream side of the oxidizing gas discharge passage 54.

  FIG. 5 is a flowchart showing the deterioration determination work executed by the worker. As shown in the drawing, when the work is started, the worker first looks into the confirmation window 69 provided in the confirmation box 60 and observes the color of the confirmation electrolyte membrane 61 (step S100). Next, the operator determines whether or not the color of the confirmation electrolyte membrane 61 has changed by a predetermined degree or more compared to when it is not used (step S110). If the degree of deterioration is large, a determination result of “abnormal” is determined (step S120). On the other hand, if it is determined that the deterioration is below a predetermined level, a determination result of “normal” is determined (step S130).

  FIG. 6 is an explanatory diagram showing how the electrolyte membrane as an example of a hydrocarbon system changes color depending on the period of use, together with the determination result. As shown in the figure, an electrolyte membrane as an example of a hydrocarbon system has a light color when the usage period is not used, and changes to a dark color as the usage period elapses. Specifically, it turns dark yellow. When the usage period is in the middle period, the color of the confirmation electrolyte membrane 61 is darkened to some extent (medium dark color), and when the usage period is longer, the color of the confirmation electrolyte membrane 61 is sufficiently dark (dark color). The operator prepares a template in which a color indicating the boundary between “normal” and “abnormal” is printed as a sample image in advance, and the color of the electrolyte membrane 61 for confirmation and the sample image observed in step S100 are displayed. In comparison, when the color of the confirmation electrolyte membrane 61 is darker than the sample image, it is determined as “abnormal”, while when it is not dark, it is determined as “normal”. That is, in step S100, whether or not the color of the confirmation electrolyte membrane 61 has changed by a predetermined degree or more is determined based on whether or not the color is darker than the sample image. In this embodiment, the color of the sample image is determined to be “normal” if the use period is about the above-mentioned medium period, and can be determined to be “abnormal” if the use period is about the above-described long period. The concentration is high. When the work of step S120 or step S130 is finished, the deterioration determination work is finished.

A-4. Action, effect:
In this embodiment, the deterioration of the fuel cell is determined using the property that the hydrocarbon-based electrolyte membrane changes to a dark color when it deteriorates. The reason why the degree of deterioration of the electrolyte membrane can be qualitatively determined by the color of the hydrocarbon electrolyte membrane is as follows.

  When a hydrocarbon electrolyte membrane is used in a fuel cell, the molecular weight of the hydrocarbon polymer material is attacked by radicals generated at the electrode, and the molecular weight (hereinafter referred to as “membrane molecular weight”). Calling) is reduced, resulting in accelerated degradation. If reduced, the degree of degradation of the electrolyte membrane is proportional to the degree of membrane molecular weight reduction. On the other hand, the relationship between the color of the electrolyte membrane and the membrane molecular weight is proportional as follows.

  FIG. 7 is an explanatory diagram showing the relationship between the color and the molecular weight of the hydrocarbon-based electrolyte membrane shown in FIG. In the figure, the molecular weight of the film is shown as a ratio with respect to the unused time, with the unused time as 100%. As shown in the figure, the membrane molecular weight is 100% when the color of the electrolyte membrane is “light”, and the membrane molecular weight is 40% when the color of the electrolyte membrane is “medium color”. When the color of the film is “dark color”, the molecular weight of the film is 20%. From this figure, it can be seen that the darker the color of the electrolyte membrane, the smaller the molecular weight of the membrane. This indicates that the degree of decrease in the molecular weight of the membrane described above is proportional to the degree of deterioration in the fuel cell, so that the degree of deterioration of the electrolyte membrane can be qualitatively determined from the color of the electrolyte membrane.

  The relationship exemplified in FIG. 7, that is, the relationship that the membrane molecular weight is smaller as the color of the electrolyte membrane is darker is considered to be due to the following reason. This is because a decrease in molecular weight causes a decrease in physical properties, resulting in a decrease in mechanical strength and a gas leak. As a result, the state of molecules changes due to oxidation, resulting in coloring. For example, when benzene is oxidized to change to quinone, absorption in the ultraviolet region increases and the color changes from transparent to yellow.

  In the fuel cell system 1 of the first embodiment, the confirmation box 60 functions as a simulation unit that makes the degradation environment of the hydrocarbon-based electrolyte membrane resemble the electrolyte membrane 11 of the fuel cell 10. That is, the confirmation box 60 is provided in the vicinity of the entrance of the oxidizing gas discharge passage 54, so that the confirmation electrolyte membrane 61 is almost the same in temperature and radical quantity as the electrolyte membrane 11 provided in the fuel cell 10. They are placed under the same deterioration environment (see (i) and (ii) described above).

  Therefore, the confirmation electrolyte membrane 61 deteriorates with the passage of time to the same extent as the electrolyte membrane 11 provided in the fuel cell 10. In turn, when the hydrocarbon electrolyte membrane deteriorates, it changes to a dark color as described above. In the present embodiment, the operator can visually know the color of the electrolyte membrane 11 provided in the fuel cell 10 by visually checking the color of the electrolyte membrane 61 for confirmation from the confirmation window 69. Therefore, the operator can determine the deterioration of the electrolyte membrane 11 provided in the fuel cell 10 with high accuracy from the color that the operator can know.

  Further, in the first embodiment, the confirmation electrolyte membrane 61 has a configuration in which the outer peripheral portion is sandwiched between the seal frames 62 and 63, so that the fuel for the technique of holding the confirmation electrolyte membrane 61 is also used. It can be similar to the battery 10. When the electrolyte membrane 61 for confirmation is subjected to repeated drying and wetting in a state where the periphery is sandwiched, it is considered that the electrolyte membrane 61 is swollen or shrunk and deteriorates. In terms of mechanical stress, the confirmation box 60 is connected to the fuel cell 10. It can be kept in the same deterioration environment. For this reason, the confirmation electrolyte membrane 61 is a better representation of the color of the electrolyte membrane 11 of the fuel cell 10 and more accurately determines the state of deterioration of the electrolyte membrane 11 provided in the fuel cell 10. be able to.

B. Second embodiment:
Next, a second embodiment of the present invention will be described. The second embodiment is different from the first embodiment only in the configuration of the confirmation box, and the other configurations are the same.

  FIG. 8 is an explanatory diagram showing the confirmation box 260 and its peripheral devices in the second embodiment. The confirmation box 260 in FIG. 8 has a vertical section. The confirmation box 260 is smaller in the size of the confirmation window 269 than the confirmation box 60 of the first embodiment. In the confirmation window 269, the spectrocolorimeter 200 is replaced with a plate glass. It is installed. The spectrocolorimeter 200 is a well-known sensor that enables colorimetry of colors by a combination of a light source, a spectroscope, and a light receiver, and uses the confirmation electrolyte membrane 61 as a target for colorimetry. The configuration of the confirmation box 260 other than the spectrocolorimeter 200 is the same as that of the first embodiment, and the same parts are denoted by the same reference numerals as those of the first embodiment.

  The fuel cell system of the second embodiment includes a control unit 210 that is electrically connected to the spectrocolorimeter 200 and an alarm lamp 220 that is electrically connected to the control unit 210. The control unit 210 is configured by a known microcomputer including a CPU, ROM, RAM (not shown) and the like. In the ROM, a computer program indicating a deterioration determination routine for determining deterioration of the fuel cell is stored in advance. The CPU executes the computer program by using the RAM as a work area. The warning light 220 is turned on when it is determined as “abnormal” by the deterioration determination routine.

  FIG. 9 is a flowchart showing a deterioration determination routine executed by the CPU of the control unit 210. This routine is repeatedly executed every predetermined time. When the processing is started, the CPU of the control unit 210 first detects the color of the confirmation electrolyte membrane 61 by the spectrocolorimeter 200 (step S300). Thereafter, the CPU calculates a density (color density) D from the color (step S310). Next, the CPU determines whether or not the color density D is equal to or higher than a predetermined density value D0 set in advance (step S320). Here, the predetermined density value D0 is a value corresponding to the color density of the sample image of the template used in the first embodiment.

  If it is determined in step S310 that the color density D is greater than or equal to the predetermined density value D0, the CPU turns on the alarm lamp 220 because the degree of deterioration of the electrolyte membrane 11 is large (step S330). Thereafter, the process returns to “Return” to end the deterioration determination routine. On the other hand, if it is determined in step S320 that the color density D is less than the predetermined density value D0, the process returns to “RETURN” without executing step S330, and this deterioration determination routine is temporarily terminated.

  According to the fuel cell system of the second embodiment configured as described above, the deterioration of the electrolyte membrane 11 provided in the fuel cell 10 can be determined with high accuracy, as in the first embodiment. In particular, in this second embodiment, the color of the confirmation electrolyte membrane 61 is measured by the spectrocolorimeter 200, not by human eyes, so that the deterioration can be automatically determined. . Further, in this embodiment, when the degree of deterioration of the electrolyte membrane 11 is large, the fact can be reported by the operator.

  In the second embodiment, the spectrocolorimeter 200 is used. Alternatively, the color density D may be directly detected using a color densitometer. Further, instead of the warning light 220, other means for issuing a warning such as a warning buzzer may be used.

C. Third embodiment:
In the first embodiment and the second embodiment, the confirmation boxes 60 and 260 are prepared as simulated units in which the degradation environment of the hydrocarbon electrolyte membrane is similar to the electrolyte membrane 11 of the fuel cell 10. , 260 is configured to detect the color of the electrolyte membrane 61 for confirmation. Instead, in the third embodiment, the color of the electrolyte membrane 11 of the fuel cell 10 is directly measured. Yes.

  FIG. 10 is an explanatory diagram showing a fuel cell system 401 as a third embodiment. The fuel cell 410 provided in the fuel cell system 401 has substantially the same configuration as the fuel cell 10 of the first embodiment. In FIG. Is drawn in a direction in which the longitudinal direction is the left and right in the figure. The difference of the fuel cell 410 from the fuel cell 10 of the first embodiment is that the protruding portion from the MEA 14 of the electrolyte membrane 11 located on the downstream side of the gas flow path 19 of the oxidizing gas, that is, the cathode electrode (catalyst) The uncovered portion PT of the layer and the gas diffusion layer) is wide. In the third embodiment, a hole 317h is provided at a position facing the non-covered portion PT of the separator 317, and a spectrocolorimeter 420 is provided in the hole 317h.

  Similar to the second embodiment, the spectrocolorimeter 420 is a well-known sensor that enables colorimetry of colors by combining a light source, a spectroscope, and a light receiver, and is in a bare state (catalyst layer and gas diffusion layer). Measure the color of the part of the electrolyte membrane that has become uncoated. The fuel cell system according to the third embodiment includes a control unit 210 that is electrically connected to the spectrocolorimeter 300 and an alarm lamp 220 that is electrically connected to the control unit 210. The control unit 210 and the warning light 220 are the same as those in the second embodiment.

  According to the third embodiment configured as described above, the deterioration of the electrolyte membrane 11 provided in the fuel cell 10 can be determined with high accuracy, as in the second embodiment. In particular, in the third embodiment, the configuration is simple because the spectrocolorimeter 420 can be provided directly on the fuel cell 10 without providing a confirmation box. In the third embodiment, the color density D may be directly detected using a color densitometer instead of the spectrocolorimeter 420, or an alarm such as an alarm buzzer may be used instead of the alarm lamp 220. Other means may be used.

D. Other embodiments:
Note that the present invention is not limited to the above-described embodiments and modifications, and can be implemented in various modes without departing from the gist thereof. For example, the following other embodiments are also possible. is there.

(1) In the first and second embodiments, the confirmation boxes 60 and 160 are provided in the vicinity of the inlet of the oxidizing gas discharge passage 54 connected to the fuel cell 10. A configuration may be adopted in which a second confirmation box is provided in the fuel gas discharge passage 34 to be connected, and deterioration of the electrolyte membrane is determined by both the confirmation boxes 60 and 160 and the second confirmation box.

(2) In the third embodiment, the spectrocolorimeter 420 is provided at a position downstream of the gas flow path 19 in the single cell of oxidizing gas. A position other than the downstream side of the gas flow path 19 may be used. Further, instead of the oxidant gas in-cell gas flow path 19 side, the fuel gas in-single cell gas flow path 18 side may be provided, and the main point is any position of the electrolyte membrane provided in the fuel cell. However, when the surface of the electrolyte membrane is in a bare state (a state in which the catalyst layer and the gas diffusion layer are not covered), the spectrocolorimeter 420 is provided so as to face this position. And it is sufficient.

(3) In the second and third embodiments, the color of the electrolyte membrane is detected by the spectrocolorimeters 200 and 420, and an alarm is issued when it is determined that the degree of deterioration of the electrolyte membrane 11 is large based on the color. The lamp 220 is turned on, but instead of this, the degree of deterioration of the electrolyte membrane 11 required based on the color may be digitized and the digitized value displayed on the display panel. . The value obtained by quantifying the degree of deterioration may be displayed graphically with a bar graph or the like.

(4) In the first to third embodiments, the fuel cell is a solid polymer fuel cell. However, the fuel cell is not necessarily a solid polymer fuel cell, and is a fuel cell including a hydrocarbon electrolyte membrane. If it exists, it is possible to apply to any kind of fuel cell.

1 is an overall configuration diagram of a fuel cell system 1 to which a first embodiment of the present invention is applied. 3 is an explanatory view showing a longitudinal section of a single cell CL of the fuel cell 10. FIG. FIG. 6 is an exploded perspective view showing a state in which the confirmation box 60 is disassembled. 4 is a cross-sectional view showing a vertical cross section of a confirmation box 60. FIG. It is a flowchart which shows the deterioration determination operation | work performed by an operator. It is explanatory drawing which shows how the electrolyte membrane as an example of a hydrocarbon type discolors with a use period with a determination result. It is explanatory drawing which shows the relationship between the color and film | membrane molecular weight about the hydrocarbon type electrolyte membrane shown in FIG. It is explanatory drawing which shows the confirmation box 260 and its peripheral device in 2nd Example. 3 is a flowchart showing a deterioration determination routine executed by a CPU of a control unit 210. It is explanatory drawing which shows the fuel cell system 401 as 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell system 10 ... Fuel cell CL ... Single cell 11 ... Electrolyte membrane 12 ... Anode electrode 13 ... Cathode electrode 14 ... MEA
DESCRIPTION OF SYMBOLS 15 ... Seal member 16 ... Separator 17 ... Separator 18 ... Gas flow path in a single cell 19 ... Gas flow path in a single cell 20 ... Fuel gas source 30 ... Fuel gas passage system 32 ... Fuel gas supply passage 34 ... For fuel gas discharge Passage 40 ... Blower 50 ... Oxidation gas passage system 52 ... Oxidation gas supply passage 54 ... Oxidation gas discharge passage 60 ... Confirmation box 61 ... Confirmation electrolyte membrane 62 ... Seal frame 64 ... Upper lid 64h ... Bolt hole 65 ... Lower lid 66 ... Bolt 67 ... Space 68 ... Space 69 ... Confirmation window 69G ... Plate glass 200 ... Spectral colorimeter 210 ... Control unit 220 ... Warning light 260 ... Confirmation box 269 ... Confirmation window 300 ... Spectral colorimeter 317 ... Separator 317h: Hole 401: Fuel cell system 410 ... Fuel cell 420 ... Spectral colorimeter PT ... Uncoated part

Claims (7)

In a fuel cell deterioration determination device that includes a hydrocarbon-based electrolyte membrane and determines deterioration of a fuel cell that generates power by supplying hydrogen-containing fuel gas to the anode electrode and oxygen-containing oxidizing gas to the cathode electrode,
It is provided near the entrance of the cathode offgas passage through which the cathode offgas discharged from the cathode electrode flows, and the confirmation electrolyte membrane of the same type as the electrolyte membrane provided in the fuel cell and the color of the confirmation electrolyte membrane can be visually observed A fuel cell deterioration determination device comprising a confirmation box comprising a confirmation window. The fuel cell deterioration determination device according to claim 1,
The confirmation box includes a frame that sandwiches the periphery of the confirmation electrolyte membrane. In a fuel cell deterioration determination device that includes a hydrocarbon-based electrolyte membrane and determines deterioration of a fuel cell that generates power by supplying hydrogen-containing fuel gas to the anode electrode and oxygen-containing oxidizing gas to the cathode electrode,
An electrolyte membrane for confirmation of the same type as the electrolyte membrane provided in the fuel cell, provided near the entrance of the cathode offgas passage through which the cathode offgas discharged from the cathode electrode flows;
A colorimetric means for measuring the color of the electrolyte membrane for confirmation;
A fuel cell deterioration determination device comprising: determination means for determining a degree of deterioration of an electrolyte membrane included in the fuel cell based on the measured color. The fuel cell deterioration determination device according to claim 3,
A fuel cell deterioration determination device further comprising alarm means for issuing an alarm when the determination means determines that the degree of deterioration is large. In a fuel cell deterioration determination device that includes a hydrocarbon-based electrolyte membrane and determines deterioration of a fuel cell that generates power by supplying hydrogen-containing fuel gas to the anode electrode and oxygen-containing oxidizing gas to the cathode electrode,
A colorimetric means for measuring the color of the electrolyte membrane;
A fuel cell deterioration determination device comprising: determination means for determining a degree of deterioration of an electrolyte membrane included in the fuel cell based on the measured color. The fuel cell deterioration determination device according to claim 5,
The fuel cell has an uncoated portion of the cathode electrode near the downstream side of the oxidizing gas in the cathode electrode,
The colorimetric means is
A fuel cell deterioration determination device having a configuration provided at an uncovered portion of the cathode electrode. The fuel cell deterioration determination device according to claim 5 or 6,
A fuel cell deterioration determination device further comprising alarm means for issuing an alarm when the determination means determines that the degree of deterioration is large.

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