JP2008034204A - Fuel cell device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell device having a means capable of judging simply and at low cost abnormality of a water pump to supply water to a reformer and abnormality of a water treatment device to refine water to be supplied to the reformer. <P>SOLUTION: The fuel cell device is provided with a fuel cell 1, a reformer 4 to carry out steam reforming for supplying a fuel gas to the fuel cell 1, a water treatment device 7 to refine water for supplying to the reformer 4, a water tank 5 to store water refined by the water treatment device, and a water pump 6 to supply the water stored in the water tank 5 to the reformer 4. By measuring conductivity of the water in the water tank 5, abnormality of the water pump 6 can be detected. Furthermore, by measuring conductivity of the water in the water tank 5, abnormality of the water treatment device 7 can be also detected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a fuel cell, a reformer that performs steam reforming to supply fuel gas to the fuel cell, a water treatment device that purifies water to be supplied to the reformer, and a water treatment device. The present invention relates to a fuel cell device including a water tank for storing fresh water, and a water pump for supplying water stored in the water tank to a reformer.

  In recent years, various fuel cells in which a plurality of fuel cell stacks are stored in a storage container and their operation methods (systems) have been proposed as next-generation energy (see, for example, Patent Document 1).

  FIG. 2 is a system configuration diagram showing a conventional fuel cell system.

  The fuel cell system in FIG. 2 includes a fuel cell 21, a fuel supply device 22 for supplying a fuel gas such as natural gas, an oxygen-containing gas supply device 23 for supplying an oxygen-containing gas to the fuel cell 21, a reformed gas, A reformer 24 for steam reforming with steam, a water treatment device 30 for purifying water supplied from a water supply pipe 32, a water supply electromagnetic valve 33 for adjusting the amount of water supplied from the water supply pipe 32, water A water tank 31 for storing the water purified by the treatment device 30 and a water pump 27 for supplying the water stored in the water tank 31 to the reformer 24 are configured.

  In the fuel cell system shown in FIG. 2, the heat exchanger 26 for exchanging the exhaust heat generated by the power generation of the fuel cell 21 to hot water, the hot water storage tank 34 for storing the hot water generated by the heat exchange, the hot water A circulation pipe 35 for circulating the gas and a circulation pump 28 are also provided.

In Patent Document 1, a water level detection switch and a conductivity type water state detection sensor are provided in the water tank, and by using these together, it is easy to determine whether or not the water level in the water tank is as set. It is described that it can be verified and whether or not the water stored in the water tank is deionized can be easily verified.
JP 2005-310615 A

  However, in Patent Document 1, it is easy to verify the water level in the water tank, but the abnormality detection means for detecting abnormality of the water pump that supplies the water stored in the water tank to the reformer. The fuel cell device is provided with a detecting means for detecting an abnormality related to the supply amount to the water tank with respect to the abnormality of the water treatment device that supplies purified water to the water tank. The device is not described.

  Furthermore, in the conventional fuel cell system as described above, for example, the water pump 27 operates normally, and water (steam) is accurately supplied from the water tank 31 to the reformer 24. There is no means for detecting whether high water (water vapor) is supplied.

  On the other hand, when confirming whether the water pump for supplying the water stored in the water tank to the reformer is operating normally, it is conceivable to measure the amount of water supplied to the reformer. However, the amount of water supplied to the reformer is very small, and currently, a flow sensor for measuring such a very small flow rate has been developed, but it has not yet been put into practical use. In addition, it is expected to be expensive.

  Here, when an abnormality occurs in the water pump and water is not supplied to the reformer, carbon is deposited on the reforming catalyst filled in the reformer, and the reforming ability of the reforming catalyst is significantly reduced. However, the power generation efficiency of the fuel cell may be reduced.

  Furthermore, when water (water vapor) is not supplied to the fuel cell, carbon is deposited on the fuel cell, causing the fuel cell itself to deteriorate, thereby reducing the power generation efficiency of the fuel cell and degrading the fuel cell. There is a risk.

  On the other hand, when an abnormality occurs in the water treatment apparatus and water is not stored in the water tank, sufficient water is not supplied to the reformer, and the reformer and the fuel cell may be deteriorated.

  Therefore, the object of the present invention is to be able to easily and inexpensively determine an abnormality of the water pump and an abnormality of the water treatment apparatus, prevent deterioration of the reformer and the fuel cell, and stabilize the operation. Another object of the present invention is to provide a fuel cell device capable of generating power from the fuel cell.

  The fuel cell device of the present invention includes a fuel cell, a reformer that performs steam reforming to supply fuel gas to the fuel cell, a water treatment device that purifies water to be supplied to the reformer, A fuel cell device comprising: a water tank for storing water purified by the water treatment device; and a water pump for supplying water stored in the water tank to the reformer. It has an abnormality detection means for detecting an abnormality of the water pump by measuring the conductivity of water.

  In the present invention, when the conductivity sensor is disposed so as to be immersed in the water stored in the water tank, when the water pump operates normally and water is supplied to the reformer, for example, from a water treatment device When the amount of water supplied to the reformer from the water tank is larger than the amount of water stored in the water tank, or when the supply of water stored in the water tank from the water treatment device is temporarily stopped, The water level in the water tank will drop. Thereby, the electrical conductivity of the water in the water tank is also lowered.

  Therefore, in the above case, when the conductivity of water in the water tank does not change even though the water pump is operating, water is not supplied to the reformer.

  In addition, by measuring in advance the change over time in the water conductivity of the water tank when the water pump is operating normally, the change over time in the conductivity of the water in the water tank is reduced to a predetermined value. When it is out of range, it can be determined that an abnormality has occurred in the water pump.

  Therefore, by measuring the conductivity of the water in the water tank, it is possible to easily and inexpensively determine the abnormality of the water pump without using an expensive flow sensor, and to prevent deterioration of the reformer and fuel cell. It is possible to provide a fuel cell device that can be prevented in advance and can stably generate power from the fuel cell.

  Further, in the fuel cell device of the present invention, the abnormality detection means interrupts the water storage in the water tank for a certain period of time, and measures the change in the conductivity of the water in the water tank during the interruption time, It is preferable to detect an abnormality of the water pump.

  By interrupting the water storage in the water tank for a certain period of time, the amount of water stored in the water tank becomes constant. Therefore, by measuring the conductivity of the water in the water tank in this state, the amount of water stored in the water tank becomes clearer and the change in the conductivity of the water in the water tank can be measured more easily. Therefore, it becomes easy to determine the abnormality of the water pump.

  The fuel cell device of the present invention includes a fuel cell, a reformer that performs steam reforming to supply fuel gas to the fuel cell, and a water treatment device that purifies water to be supplied to the reformer. And a water tank for storing the water purified by the water treatment device, and a water pump for supplying the water stored in the water tank to the reformer. It has an abnormality detecting means for detecting an abnormality of the water treatment device by measuring conductivity of water in the water tank when water is supplied to the device.

  In the water treatment apparatus, although the degree of purification of water supplied to the water tank is normal, an abnormality such as an insufficient amount of supplied water may occur.

  If the abnormality continues for a long time, sufficient water is not supplied to the water tank, the water tank is depleted, and sufficient water cannot be supplied to the reformer. There is a possibility that the reforming efficiency of the fuel gas deteriorates or the reformer deteriorates.

  Here, when water is supplied to the water treatment device, for example, the amount of water stored in the water tank from the water treatment device is set larger than the amount of water supplied from the water tank to the reformer. When the operation of the water pump is temporarily stopped, the water purified by the water treatment device is stored in the water tank, and the water level in the water tank rises. Thereby, the electrical conductivity of the water in a water tank will rise.

  Therefore, in the above-mentioned case, by measuring in advance the change over time of the water conductivity in the water tank when the water treatment device is operating normally, the conductivity of the water in the water tank is measured. If the change over time falls below a predetermined range or has not changed, it can be determined that an abnormality has occurred in the water treatment apparatus.

  Therefore, when water is supplied to the water treatment device, it is possible to determine the abnormality of the water treatment device by measuring the conductivity of the water in the water tank, and to deteriorate the reformer and the fuel cell. A fuel cell device that can be prevented in advance can be provided.

  In the fuel cell of the present invention, it is preferable to switch the fuel gas reforming method from the steam reforming method to the partial oxidation reforming method when an abnormality occurs in the water pump or the water treatment device.

  If the power generation of the fuel cell is continued when the water pump or the water treatment apparatus shows an abnormality, the reformer and the fuel cell may be deteriorated.

  In the present invention, when an abnormality occurs in the water pump or the water treatment apparatus, the reformed gas is stably supplied to the fuel cell by switching the reforming method of the fuel gas from the steam reforming method to the partial oxidation reforming method. Therefore, it is easy to effectively prevent deterioration of the reformer and the fuel cell. Accordingly, it becomes easy to provide a fuel cell device that can stably generate power from the fuel cell.

  Since the fuel cell device of the present invention can easily and inexpensively detect an abnormality of the water pump and an abnormality of the water treatment device, it is possible to prevent the reformer and the fuel cell from deteriorating in a stable manner. Thus, a fuel cell device capable of generating power from the fuel cell can be provided.

  FIG. 1 is a configuration diagram showing an example of the configuration of the fuel cell device of the present invention. The fuel cell device of the present invention includes a fuel cell 1, a fuel supply device 2, an oxygen-containing gas supply device 3 for supplying an oxygen-containing gas to the fuel cell 1, a reformer 4 for reforming a gas to be reformed, and water supply In order to store the water purified by the water treatment device 7 for purifying the water supplied from the pipe 9, the water supply electromagnetic valve 8 for adjusting the amount of water supplied from the water supply pipe 9, and the water treatment device 7. Water tank 5 and water pump 6 for supplying the reformer 4 with water stored in the water tank 5 (including water vapor in the present invention, the following agreement). Although not shown, the water treatment device 7 may be provided with a drain pipe for discharging unnecessary water.

  The water tank 5 is provided with a water level detection device 11 that detects the water level of the water tank 5 and a conductivity sensor 10 that measures the conductivity of water in the water tank 5. Moreover, based on the water level information of the water tank 5 detected by the water level detection device 11, there is provided a control device 12 that controls the water supply electromagnetic valve 8 for adjusting the amount of water supplied from the water supply pipe 9. .

  Water used for power generation of the fuel cell device is supplied to the water treatment device 7 through the water supply pipe 9 by opening the water supply electromagnetic valve 8 according to a command from the control device 12. The supplied water is purified to a highly purified water (preferably pure water) by the water treatment device 7 and stored in the water tank 5. The highly purified water stored in the water tank 5 is supplied to the reformer 4 by the water pump 6 and reacts with the reformed gas supplied from the fuel supply device 2 to reform the reformed gas. To produce fuel gas. Then, the reformed fuel gas is sent to the fuel cell 1 and the fuel cell 1 generates power.

  Here, the conductivity sensor 10 is disposed so as to be immersed in the water stored in the water tank 5. Therefore, the water level in the water tank 5 is set to a predetermined water level so that the conductivity sensor 10 is immersed. Here, it is preferable to arrange the conductivity sensor 10 so as to be completely immersed in the water stored in the water tank 5 because the change in the water level of the water tank 5 is more easily sensed. The predetermined water level is preferably full.

  The water pump 6 sets the amount of water supplied from the water tank 5 to the reformer 4 according to the amount of fuel gas supplied to the reformer 4, for example, 0.5 mL / min to 10 mL / min. It is set to a small amount.

  Here, for example, when the amount of water supplied from the water tank 5 to the reformer 4 is set larger than the amount of water stored in the water tank 5 from the water treatment device 7, or the water treatment device 7. When the supply of water stored in the water tank 5 is temporarily stopped and the water pump 6 operates normally and water is supplied to the reformer 4, the water level of the water tank 5 is lowered, The conductivity of water in the water tank 5 measured by the conductivity sensor 10 is also lowered.

  In other words, if the conductivity of the water in the water tank 5 does not change even though the water pump 6 is operating, water is not supplied to the reformer 4, and the water pump 6 It can be determined that an abnormality such as a lock has occurred.

  Further, by measuring in advance the change over time in the conductivity of water in the water tank 5 when the water pump 6 is operating normally, the conductivity of the water in the water tank 5 is within a predetermined range. When an outside value is indicated, it can be determined that an excessive or insufficient amount of water is supplied to the reformer 4 and an abnormality has occurred in the water pump 6.

  On the other hand, in the present invention, it is preferable to interrupt the water storage in the water tank 5 for a certain period of time and measure the conductivity of the water in the water tank 5 during the interruption time.

  As such a method, for example, the water level of the water tank is detected by the water level detection device 11 provided in the water tank 5. Here, when the water level detection device 11 detects a preset water level (for example, full water) in the water tank 5, the water level information is transmitted to the control device 12, and a command to close the water supply electromagnetic valve 8 from the control device 12. Is transmitted. Thereby, the water supply electromagnetic valve 8 is closed, and the water storage in the water tank 5 is interrupted for a certain time. That is, the amount of water stored in the water tank 5 is constant during the interruption for a certain period of time. The water level detection device 11 includes, for example, a water meter, a water amount sensor, a float switch, and the like, which can be appropriately selected and used.

  Then, by operating the water pump 6 in this state and measuring the conductivity of the water in the water tank 5, the amount of water stored in the water tank 5 becomes clearer, and the change in the conductivity of the water is changed. Since it becomes easier to measure, it is possible to easily determine the abnormality of the water pump 6.

  Further, by preliminarily defining the temporal change in the electrical conductivity of the water in the water tank 5 when the water pump 6 is operating normally, the temporal change in the electrical conductivity of the water in the water tank 5 is predetermined. If it falls below the range, it can be determined that the water supply by the water pump 6 is low. Moreover, when it exceeds the predetermined range, it can be determined that the supply of water by the water pump is excessive. Therefore, when the conductivity of the water in the water tank falls outside the predetermined range, it can be determined that an abnormality has occurred in the water pump.

  At that time, for example, when an abnormality has occurred in the water pump 6, a warning signal transmitting means for transmitting a warning signal notifying the abnormality can be provided. By transmitting a warning signal notifying the abnormality of the water pump 6, it is possible to recognize that the water pump 6 is abnormal, and it becomes easy to appropriately replace the water pump 6.

  As a result, it is possible to prevent the water pump from continuously generating power while the water pump is abnormal, and it is easy to prevent the reformer 4 and the fuel cell 1 from being deteriorated, and the like. It is easy to generate power from the fuel cell 1.

  Such warning signals include, for example, a buzzer that sounds when the water pump 6 becomes abnormal, a display device that indicates an abnormality of the water pump 6, and that the water pump 6 is abnormal. Devices such as telephones and personal computers that send e-mails can be appropriately selected and used.

  Moreover, in this embodiment, although the case where water was supplied to the reformer 4 from the water pump 6 was demonstrated, for example, the water supplied from the water pump 6 is supplied to the fuel humidifier, and the humidified fuel is supplied. You may make it supply to the reformer 4. FIG.

  Moreover, in this invention, when water is supplied to the water treatment apparatus 7, the abnormality of the water treatment apparatus 7 can be detected by measuring the conductivity of the water in the water tank 5.

  Although the water treatment device 7 has a normal purity of the water supplied to the water tank 5, an abnormality such as a shortage of the supplied water may occur.

  In this case, if any abnormality occurs in the water treatment device 7, sufficient water cannot be stored in the water tank. If the abnormality continues for a long time, sufficient water is stored in the water tank. Not supplied, the water tank 5 is depleted and sufficient water cannot be supplied to the reformer 4, and the reforming efficiency of the fuel gas in the reformer 4 deteriorates or the reformer 4 deteriorates. There is a risk of doing.

  The water stored in the water tank 5 is purified by the water treatment device 7 after the water supply electromagnetic valve 8 is opened and water is supplied to the water treatment device 7 from the water supply pipe 9 according to the command of the control device 12. Water is stored in the tank 5.

  Here, in the case where water is supplied to the water treatment device 7, for example, water stored in the water tank 5 from the water treatment device 7 based on the amount of water supplied from the water tank 5 to the reformer 4. When a large amount is set or when the operation of the water pump 6 is temporarily stopped, the water purified by the water treatment device 7 is stored in the water tank 5 and the water level in the water tank 5 is set. To rise. Thereby, the electrical conductivity of the water in the water tank 5 will rise.

  Therefore, the change with time of the conductivity of water in the water tank 5 is measured in advance by measuring the change with time of the conductivity of the water in the water tank 5 when the water treatment device 7 is operating normally. However, when a value outside the predetermined range is indicated or when the value does not change, it can be determined that an abnormality has occurred in the water treatment device 7. In other words, the replacement time of the water treatment device 7 is known.

  Therefore, when water is supplied to the water treatment device 7, by measuring the conductivity of the water in the water tank 5, the abnormality of the water treatment device 7 can be easily and inexpensively determined. It is possible to prevent deterioration of the container 4 and the fuel cell 1 and the like, and it is easy to stably generate power in the fuel cell 1. The

  In the present invention, by measuring the conductivity of water in the water tank 5, it is also possible to detect an abnormality such as a reduction in the purity of the water supplied from the water treatment device 7.

  The water supplied from the outside of the fuel cell device is purified by the water treatment device 7 and then stored in the water tank 5. However, if the water treatment device 7 is used for a long period of time, the purification capacity of the water treatment device 7 is reduced, and the water supplied to the water tank may be water with a low purity, that is, pure water with low purity.

  Here, the conductivity sensor 10 is disposed so as to be immersed in the water stored in the water tank 5, and the water level in the water tank 5 is set to a predetermined water level so that the conductivity sensor 10 is immersed. . At this time, if the conductivity sensor 10 is disposed so as to be completely immersed in the water stored in the water tank 5, it is easier to detect a change in the water level of the water tank 5, for example, the water level of the water tank 5 is filled. It is preferable.

  When the purity of water is low, that is, when the purity of pure water is low (there are many impurities), the conductivity measured by the conductivity sensor 10 is a high value, and in some cases, a very high value.

  Therefore, for example, when the water tank 5 reaches a predetermined water level (preferably when it is full), by setting a range of conductivity that is acceptable as water that can be supplied to the reformer 4, When the conductivity of the water is measured and it is outside the allowable range, it is easy to determine that the degree of purification of the water purified by the water treatment device 7 is low. That is, it becomes easy to determine the replacement time of the water treatment device 7.

  Therefore, by measuring the conductivity of the water in the water tank 5, it is possible to easily and inexpensively determine the abnormality of the water treatment device 7, and to prevent deterioration of the reformer 4 and the fuel cell 1. This makes it easy to generate power from the fuel cell 1 stably.

  Moreover, when abnormality has arisen in the water treatment apparatus 7, the warning signal transmission means which transmits the warning signal which notifies abnormality can also be comprised. By transmitting a warning signal notifying the abnormality of the water treatment apparatus 7, it is possible to recognize that the water treatment apparatus 7 is abnormal, and it becomes easy to appropriately replace the water treatment apparatus 7.

  As a result, it is possible to prevent the water treatment device 7 from continuing to generate power in the fuel cell while it is abnormal, and it is easy to prevent deterioration of the reformer 4 and the fuel cell 1 and the like. Thus, it becomes easy to generate power from the fuel cell 1.

  As such a warning signal, for example, a buzzer that makes a sound when the water treatment apparatus 7 becomes abnormal, a display device that indicates an abnormality of the water treatment apparatus 7, and the water treatment apparatus 7 are abnormal. It is possible to appropriately select and use a device or the like that transmits the information to a mail such as a mobile phone or a personal computer.

  In the present invention, the abnormality detection means (water pump abnormality detection means) for detecting an abnormality of the water pump 6 and the abnormality detection means (water treatment apparatus abnormality detection means) for detecting an abnormality of the water treatment device 7 are the same. It is also possible to do this by means.

  Further, when the water pump 6 or the water treatment device 7 shows an abnormality and the power generation of the fuel cell is continued, the reformer 4 and the fuel cell 1 may be deteriorated. Therefore, the fuel cell of the present invention can switch the fuel gas reforming method from the steam reforming method to the partial oxidation reforming method when the water pump 6 or the water treatment device 7 is abnormal.

  Since the reforming method of the fuel gas in the reformer 4 is switched from the steam reforming method to the partial oxidation reforming method, the reformed gas can be stably provided to the fuel cell 1. 4 and the deterioration of the fuel cell 1 and the like can be effectively prevented, and it is easy to stably generate power from the fuel cell.

  In this case, if the water pump 6 or the water treatment device 7 becomes abnormal, the fuel gas reforming method is immediately switched from the steam reforming method to the partial oxidation reforming method. It is also possible to switch to the quality method.

  That is, when the water pump 6 or the water treatment device 7 cannot be replaced within a certain time after the water pump 6 or the water treatment device 7 has failed, the reforming method of the fuel gas in the reformer 4 is changed to the steam. By switching from the reforming method to the partial oxidation reforming method, it becomes easy to stably generate power in the fuel cell 1.

  In addition, when the water pump 6 or the water treatment device 7 has an abnormality, if it has warning signal transmission means for transmitting a warning signal, for example, an abnormality of the water pump 6 or the water treatment device 7 is indicated. If the water pump or water treatment device cannot be replaced within a certain time after sending a warning signal for a certain time, the fuel gas reforming method in the reformer is switched from the steam reforming method to the partial oxidation reforming method. It is also possible to set.

  In that case, when the water pump 6 or the water treatment device 7 cannot be replaced within a certain time after the warning signal is transmitted for a certain time, the reforming method of the fuel gas in the reformer 4 is changed from the steam reforming method. By switching to the partial oxidation reforming method, the reformed gas can be stably provided to the fuel cell. Therefore, it is easy to effectively prevent the deterioration of the reformer 4 and the fuel cell 1, and the like. This makes it easy to generate power from the fuel cell 1.

  As a method for switching the fuel gas reforming method, for example, a stop command is transmitted from the control device 12 to the water pump 6, and the oxygen-containing gas is supplied to the oxygen-containing gas supply device 3 to the reformer 4. By transmitting the command to, it is possible to continuously perform the reforming of the fuel gas by the partial oxidation reforming reaction and to continuously operate the fuel cell 1.

  In the fuel cell device of the present invention, the fuel cell device further includes warning signal transmission means after the water pump 6 or the water treatment device 7 shows an abnormality or after a certain time has passed since the abnormality was shown. In this case, the power generation of the fuel cell 1 can be stopped after a warning signal is transmitted (preferably after a predetermined time is transmitted).

  That is, when the water pump 6 or the water treatment device 7 shows an abnormality and the power generation of the fuel cell 1 is continued, the reformer 4 and the fuel cell 1 may be deteriorated.

  In the present invention, when the water pump 6 or the water treatment device 7 shows an abnormality, the power generation of the fuel cell 1 is stopped, so that deterioration of the reformer 4 and the fuel cell 1 can be effectively prevented. It becomes easy.

  Even when the water pump 6 or the water treatment device 7 is not noticed abnormal, the power generation of the fuel cell 1 is stopped and the power supply is stopped, so that the water pump 6 or the water treatment device 7 has an abnormality. It becomes easy to recognize that this has occurred, that is, that an abnormality has occurred in the fuel cell device.

It is a block diagram which shows the structure of the fuel cell apparatus of this invention. It is a block diagram which shows the structure of the conventional fuel cell apparatus.

Explanation of symbols

1: Fuel cell 2: Fuel supply device 3: Oxygen-containing gas supply device 4: Reformer 5: Water tank 6: Water pump 7: Water treatment device 8: Water supply solenoid valve 9: Water supply pipe 10: Conductivity sensor 11: Water level detection device 12: Control device

Claims (4)

A fuel cell, a reformer that performs steam reforming to supply fuel gas to the fuel cell, a water treatment device that purifies water to be supplied to the reformer, and purified by the water treatment device In a fuel cell device comprising a water tank for storing water and a water pump for supplying the water stored in the water tank to the reformer, the conductivity of the water in the water tank is measured. The fuel cell device further comprises abnormality detecting means for detecting abnormality of the water pump. The abnormality detection means detects abnormality of the water pump by suspending water storage in the water tank for a certain period of time and measuring a change in conductivity of the water in the water tank during the interruption time. The fuel cell device according to claim 1, wherein A fuel cell, a reformer that performs steam reforming to supply fuel gas to the fuel cell, a water treatment device that purifies water to be supplied to the reformer, and purified by the water treatment device In a fuel cell device comprising a water tank for storing water and a water pump for supplying water stored in the water tank to the reformer, when water is supplied to the water treatment device An abnormality of the water treatment device is detected by measuring the conductivity of water in the water tank. 4. The fuel gas reforming method is switched from a steam reforming method to a partial oxidation reforming method when the water pump or the water treatment apparatus is abnormal. A fuel cell device according to claim 1.

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