JP2010009752A - Fuel cell device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell device with improved reliability capable of restraining clogging of a water-supplying pipe for supplying water from a water tank to a reformer and a failure of the reformer in case of start-up or restart-up of the fuel cell device. <P>SOLUTION: At startup of the fuel cell device, a water pump 11 is made to operate after a heating part 24 heats water stored in the water tank 10. The heating part 24 is equipped with a control apparatus 14 which controls the water pump 11 and a valve 22, respectively, so as to open a drainage pipe 23 to drain water flowing in the water-supplying pipe 5 during a predetermined period after the water pump 11 begins to operate. Then, the clogging of the water supplying pipe 5 for supplying water from the water tank 10 to the reformer 4 and the trouble of the reformer 4 can be restrained, and the fuel cell device can be improved in its reliability. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell device including a fuel cell and a reformer for generating a reformed gas necessary for power generation of the fuel cell.

  In recent years, as a next-generation energy, a fuel cell in which a fuel cell in which a cell stack formed by arranging a plurality of fuel cells is stored in a storage container, and auxiliary equipment for operating the fuel cell are stored in an outer case Various devices have been proposed.

  In such a fuel cell device, power generation is performed by supplying a reformed gas (fuel gas) and an oxygen-containing gas to the fuel cell. Here, the reformed gas supplied to the fuel battery cell is generated by reforming the reformed gas (raw fuel) in the reformer, and the reforming method uses water (steam). A steam reforming method that performs a reforming reaction can be used.

  By the way, in a fuel cell device including a reformer that performs steam reforming, pure water is used as water to be supplied to the reformer. However, pure water becomes an environment in which microorganisms are likely to be generated. Here, if microorganisms or the like are generated in the water supplied to the reformer, it may cause problems such as clogging of the piping, which may adversely affect the operation of the fuel cell device.

Therefore, a method for sterilizing microorganisms contained in water stored in the water tank and supplied to the reformer has been proposed. For example, the temperature of the recovered water in the recovered water tank is temporarily set to 70 ° C. or higher. A method of dissolving or dispersing an organic antibacterial antifungal agent that does not contain chlorine, sulfur, or fluorine in water depending on the method or the temperature of the water tank has been proposed (see, for example, Patent Document 1 and Patent Document 2). ).
JP-A-8-138714 JP 2002-343393 A

  By the way, in a fuel cell device that generates power using fuel gas generated by steam reforming, the operation of the fuel cell device is stopped due to a malfunction or periodic inspection of each device for supplying water to the reformer. There are cases where maintenance such as component replacement is performed, and the operation of the fuel cell device is started (restarted) after the maintenance.

  Here, when the fuel cell device is stopped for a long period of time, microorganisms may be generated in the water stored in the water tank or the water supply pipe. Here, when the fuel cell device is started (restarted) after being stopped for a long time, the water supply pipe for supplying water from the water tank into the reformer is clogged, and the water necessary for steam reforming is supplied. May be difficult, and the reforming catalyst disposed in the reformer may be deteriorated.

  Therefore, in the present invention, when starting (restarting) a fuel cell device, a fuel cell device capable of suppressing (preventing) clogging of a water supply pipe due to microorganisms or the like or failure of a reformer is provided. The purpose is to do.

  The fuel cell device of the present invention includes a fuel cell, a reformer for generating reformed gas to be supplied to the fuel cell, a water tank for storing water to be supplied to the reformer, A water supply pipe for guiding the water stored in the water tank to the reformer; and a water pump connected to the water supply pipe for supplying the water stored in the water tank to the reformer. In the fuel cell device, the water supply pipe between the reformer and the water pump has a drain pipe for draining water from the water feed pipe and a valve for opening and closing the drain pipe, and the water The tank has a heating unit for heating the water stored in the water tank, and when the fuel cell device is started, the heating unit heats the water stored in the water tank. And operating the water pump for a predetermined time after operating the water pump. To open the drain pipe to drain the water flowing through the water pipe, characterized by comprising a control device for controlling each of the heating unit, the water pump and the valve.

  In such a fuel cell device, when the fuel cell device is activated, the water stored in the water tank can be sterilized by heating the water stored in the water tank. Further, by draining the water flowing through the water supply pipe from the drain pipe for a predetermined time after operating the water pump, for example, when restarting the fuel cell device, the water pipe connecting the water tank and the water pump Even if microorganisms or the like are generated in the water remaining in the water, the water containing the microorganisms is drained from the drain pipe, so that clogging of the water supply pipe can be suppressed and water containing the microorganisms is supplied to the reformer. Can be suppressed.

  Further, by providing the drain pipe so as to be positioned in the water supply pipe between the reformer and the water pump, at least water remaining in the water supply pipe between the water tank and the water pump is supplied to the reformer. This can be suppressed.

  Thereby, when starting or restarting the fuel cell device, it is possible to suppress clogging of the water supply pipe for supplying water from the water tank to the reformer, and to suppress the failure of the reformer, A fuel cell device with improved reliability can be obtained.

  In the fuel cell device of the present invention, it is preferable that the heating unit raises the water stored in the water tank to a temperature at which microorganisms contained in the water stored in the water tank can be heat sterilized.

  Thereby, the microorganisms contained in the water stored in the water tank can be effectively sterilized, and the water supply pipe for supplying water from the water tank to the reformer when starting or restarting the fuel cell device As a result, it is possible to suppress the failure of the reformer and to obtain a fuel cell device with improved reliability.

  In the fuel cell device of the present invention, it is preferable that the control device controls the valve so as to close the drain pipe after a predetermined time has elapsed since the water pump was operated.

  In such a fuel cell device, the control device controls the valve so that the drain pipe is closed after a lapse of a predetermined time after operating the water pump, so that the water (pure water) not containing microorganisms can be efficiently modified. Can be supplied to the quality device.

  The fuel cell device of the present invention includes a fuel cell, a reformer for generating reformed gas to be supplied to the fuel cell, a water tank for storing water to be supplied to the reformer, A water supply pipe for guiding the water stored in the water tank to the reformer; and a water pump connected to the water supply pipe for supplying the water stored in the water tank to the reformer. In the fuel cell device, the water supply pipe between the reformer and the water pump has a drain pipe for draining water from the water feed pipe and a valve for opening and closing the drain pipe, and the water The tank has a heating unit for heating the water stored in the water tank, and when the fuel cell device is started, the heating unit heats the water stored in the water tank. And operating the water pump for a predetermined time after operating the water pump. In the case of starting or restarting the fuel cell device, the control device controls each of the heating unit, the water pump and the valve so as to open the drain pipe to drain the water flowing through the water pipe. Further, it is possible to suppress clogging of a water supply pipe for supplying water from the water tank to the reformer and to prevent the reformer from failing, and a fuel cell device with improved reliability can be obtained.

  FIG. 1 is a configuration diagram showing an example of a configuration of a fuel cell system including a fuel cell device of the present invention. The fuel cell device of the present invention corresponds to a power generation unit that generates power in FIG. 1, and includes a hot water storage unit that stores hot water after heat exchange, and a circulation pipe that circulates water between these units. A battery system is configured. In addition, it can also be set as the fuel cell apparatus of this invention including a hot water storage unit and circulation piping.

  A fuel cell apparatus (system) shown in FIG. 1 includes a fuel cell (cell) 1, a reformed gas supply means 2 for supplying a reformed gas such as natural gas or kerosene, and an oxygen-containing gas to the fuel cell 1. And a reformer 4 for steam reforming with a gas to be reformed and steam.

  Further, in the fuel cell device (power generation unit) shown in FIG. 1, a heat exchanger 13 that performs heat exchange between exhaust gas (exhaust heat) generated by power generation of the fuel cell 1 and water, and condensed water generated by heat exchange. The condensed water treatment device 19 for treating the condensed water, and the condensed water supply pipe 21 for supplying the condensed water generated by the heat exchanger 13 to the condensed water treatment device 19 are provided. The condensed water is stored in the water tank 10 and then supplied to the reformer 4 by the water pump 11. In addition, the condensed water processing means (for example, ion exchange resin etc., not shown) for processing condensed water can be provided not only in the condensed water processing apparatus 19 but also in the condensed water supply pipe 21 and the like. The water tank 10 is provided with a heating unit 24 for heating the water stored in the water tank 10. The heating unit 24 will be described in detail later.

  On the other hand, when the amount of condensed water supplied to the condensed water treatment device 19 is small or when the purity of condensed water after being treated by the condensed water treatment means is low, water supplied from the outside (such as tap water) Can be treated with pure water and supplied to the reformer 4. In FIG. 1, each water treatment device is provided as means for treating the water supplied from the outside into pure water.

  Here, as each water treatment device for supplying the water supplied from the outside to the reformer 4, the activated carbon filter device 7 for purifying the water, the reverse osmosis membrane device 8, and the purified water is purified water. At least the ion exchange resin device 9 (preferably all devices) is included among the devices of the ion exchange resin device 9 for achieving the above. The pure water generated by the ion exchange resin device 9 is stored in the water tank 10. In addition, in FIG. 1, while providing all the said apparatuses as a water treatment apparatus, the water supply valve 6 for adjusting the quantity of the water supplied from the outside is provided. Further, the condensed water treatment device 19 and the water tank 10 are connected by a tank connecting pipe 20. In the case where only condensed water is supplied to the reformer 4, the condensed water treatment device 19 and the reformer 4 can be connected via the water pump 11.

  In addition, each water treatment device and condensate treatment device for supplying water to the reformer 4 are collectively represented as a water supply device X, which is shown by being surrounded by a one-dot chain line in FIG. The water supply pipe 5, the tank connection pipe 20, and the condensed water supply pipe 21 that connect the container 4 and the water pump 11 are also included in the water supply apparatus X).

  Further, the fuel cell device shown in FIG. 1 is provided at the outlet of the power conditioner 12 and the heat exchanger 13 for switching the DC power generated by the fuel cell 1 to AC power and supplying it to an external load. In addition to the outlet water temperature sensor 15 for measuring the temperature of the water flowing through the outlet (circulated water stream), a control device 14 is provided, and a power generation unit is configured together with the circulation pump 16. The control device 14 will be described in detail later. And each apparatus which comprises these electric power generation units can be set as a fuel cell apparatus with easy installation, carrying, etc. by accommodating in an exterior case. Although not shown, a to-be-reformed gas humidifier for humidifying the to-be-reformed gas may be provided between the to-be-reformed gas supply means 2 and the reformer 4. The hot water storage unit includes a hot water storage tank 18 for storing hot water after heat exchange.

  In FIG. 1, out of the water supply pipe 5 for guiding water to the reformer 4, the water flowing through the water supply pipe 5 is drained into the water supply pipe 5 connecting the reformer 4 and the water pump 11. The drain pipe 23 is provided, and a valve 22 for opening and closing the drain pipe 23 is provided at a connection portion between the drain pipe 23 and the water supply pipe 5.

  In addition, the arrow in a figure shows the flow direction of to-be-reformed gas, oxygen-containing gas, and water, and a broken line is transmitted from the main signal path | route transmitted to the control apparatus 14, or the control apparatus 14. Main signal paths are shown. The same components are denoted by the same reference numerals, and so on.

  Here, a method of operating the fuel cell device shown in FIG. 1 will be described. In performing steam reforming to generate reformed gas (fuel gas) used for power generation of the fuel cell 1, water (pure water) used in the reformer 4 is converted into the fuel cell 1 in the heat exchanger 13. Condensed water generated by heat exchange between the exhaust gas generated by the power generation and the water flowing through the circulation pipe 17 is used. The condensed water generated in the heat exchanger 13 flows through the condensed water supply pipe 21 and is supplied to the condensed water treatment device 19. Condensed water (pure water) processed by the condensed water processing means (ion exchange resin or the like) provided in the condensed water processing device 19 is supplied to the water tank 10 via the tank connecting pipe 20. The water stored in the water tank 10 is supplied to the reformer 4 by the water pump 11, subjected to steam reforming with the reformed gas supplied from the reformed gas supply means 2, and generated reformed. A quality gas (fuel gas) is supplied to the fuel cell 1. In the fuel cell 1, power generation is performed using the reformed gas and the oxygen-containing gas supplied from the oxygen-containing gas supply means 3. By the above method, the water self-sustained operation can be performed by effectively using the condensed water.

  On the other hand, when the amount of condensed water produced is small, or when the purity of the condensed water treated by the condensed water treatment device 19 is low, water (such as tap water) supplied from the outside can be used.

  In this case, first, the water supply valve 6 (for example, an electromagnetic valve or an air drive valve) is opened, and water supplied from the outside such as tap water is supplied to the activated carbon filter 7 through the water supply pipe 5. The water treated with the activated carbon filter 7 is then supplied to the reverse osmosis membrane 8. The water treated by the reverse osmosis membrane 8 is continuously supplied to the ion exchange resin device 9, and pure water generated by being treated by the ion exchange resin device 9 is stored in the water tank 10. The pure water stored in the water tank 10 is used for power generation of the fuel cell 1 by the method described above.

  By the way, in the case of a malfunction or periodic inspection of the water supply device X (for example, the condensate treatment device 19), the operation of the fuel cell device is stopped for a long time to perform maintenance such as replacement of parts and the operation of the fuel cell device is started after maintenance (Resume).

  Here, when the fuel cell device is stopped for a long period of time, microorganisms may be generated in water stored in the water tank 10 or water remaining in the water supply pipe 5 connecting the water tank 10 and the water pump 11. . Even when the fuel cell device is first activated, if the time from when pure water is replenished to the water tank 10 until the first activation becomes longer, microorganisms are similarly added to the water stored in the water tank 10. May occur.

  Here, when microorganisms are generated in the water stored in the water tank 10 or in the water remaining in the water supply pipe 5 connecting the water tank 10 and the water pump 11, there is a risk that the water supply pipe 5 may be clogged by the microorganisms, Depending on the type, the reforming catalyst (not shown) provided in the reformer 5 may be deteriorated. Here, if the water supply pipe 5 is clogged or the reforming catalyst is deteriorated, it is difficult to efficiently generate power from the fuel cell 1.

  Therefore, in the present invention, at the time of starting or restarting the fuel cell device, the control device 14 operates the water pump 11 after the heating unit 24 heats the water stored in the water tank 10, and the water pump 11. The valve 22 is controlled so that the water flowing through the water supply pipe 5 is drained from the drain pipe 23 by opening the drain pipe 23 for a predetermined time after the operation. That is, when the fuel cell device is started or restarted, the control device 14 controls the operations of the heating unit 24, the water pump 11, and the valve 22.

  Specifically, the control device 14 first controls the heating unit 24 to operate so as to heat the water stored in the water tank 10. Here, as the heating unit 24, for example, a heater or the like can be used. When using a heater, the heater may be provided inside the water tank 10 or outside. Moreover, it is preferable that the control apparatus 14 controls the heating part 24 to raise the water stored in the water tank 10 to a temperature at which microorganisms can be sterilized by heating. For example, the temperature of the water stored in the water tank 10 is It is preferable to control the operation of the heating unit 24 so as to be 60 ° C. or higher. In controlling the operation of the heating unit 24, a temperature sensor for measuring the temperature of the water stored in the water tank 10 can be provided in the water tank 10.

  Here, the operation of the heating unit 24 can be set as appropriate based on the temperature of the water stored in the water tank 10. For example, when the temperature of the water stored in the water tank 10 is increased to 70 ° C. It is preferable to operate the heating unit 24 so that 70 ° C. can be maintained for 15 seconds. By the way, in this specification, “after heating” means after heating so that the water stored in the water tank 10 is at least 60 ° C. or more, more preferably the water stored in the water tank 10. Means after heat sterilization.

  The heating unit 24 preferably increases the temperature of the water stored in the water tank 10 to a temperature at which microorganisms can be sterilized by heating, but the heated water is supplied to the reformer 4. Therefore, it is preferable to set the operation of the heating unit 24 in consideration of the heat resistance of the water supply pipe 5 and the water pump 11.

  And since the control apparatus 14 controls the heating part 24 so that the water stored in the water tank 10 may be heated at the time of starting (restarting) the fuel cell apparatus, the water stored in the water tank 10 Even when microorganisms are generated, the microorganisms can be effectively sterilized, so that the water supply pipe 5 can be prevented from clogging and the reformer 4 from being damaged.

  Subsequently, the control device 14 performs control to operate the water pump 11 after performing control to stop the heating unit 24 after heat sterilizing the water stored in the water tank 10. In addition, when the heat resistance of the water supply pipe 5 or the water pump 11 is low, the control device 14 is configured such that the temperature of the water stored in the water tank 10 measured by the temperature sensor provided in the water tank 10 is equal to or lower than a predetermined temperature. After that, it is preferable to perform control to operate the water pump 11.

  At the same time, the control device 14 controls the valve 22 to open the drain pipe 23 to drain the water flowing through the water supply pipe 5 for a predetermined time after the water pump 11 is operated.

  In particular, when the fuel cell device is restarted, when water remains in the water supply pipe 5 connecting the water tank 10 and the reformer 4, particularly in the water supply pipe 5 connecting the water tank 10 and the water pump 11. There is.

  Here, when the fuel cell apparatus is stopped for a long time as described above, microorganisms may be generated in the water remaining in the water supply pipe 5. Then, when the water in which the microorganisms are generated is supplied to the reformer 4, depending on the type of the generated microorganisms, a reforming catalyst (not shown) included in the reformer 4 is deteriorated. 5 may be clogged.

  Therefore, the control device 14 operates the water pump 11 to control the valve 22 to open the drain pipe 23 for a predetermined time (performs control to open the valve 22). Thereby, water remaining in at least the water supply pipe 5 connecting the water tank 10 and the water pump 11 can be drained from the drain pipe 23, and the supply of water containing microorganisms to the reformer 4 is suppressed. be able to.

  The period of time during which the water pump 11 is operated is a time during which at least water remaining in the water supply pipe 5 connecting the water tank 10 and the water pump 11 can be drained from the drain pipe 23. The water supply pipe 5 connecting the water tank 10 and the water pump 11 can be appropriately set according to the length and thickness of the water supply pipe 5 and the water supply capacity of the water pump 11. In order to suppress the supply of water containing microorganisms to the reformer 4, water remaining in the water supply pipe 5 connecting the water tank 10 and the water pump 11 is discharged from the drain pipe 23 for a predetermined time. It can also be longer (slightly longer) than the time that can be drained.

  Further, the valve 22 and the drain pipe 23 are connected to the water supply pipe 5 that connects the water pump 11 and the reformer 4 in order to suppress the water remaining in the water supply pipe 5 from being supplied to the reformer 4. Of the water supply pipe 5 that connects the water pump 11 and the reformer 4, it is preferably connected to the reformer 4 side. Thereby, supply of water containing microorganisms to the reformer 4 can be effectively suppressed.

  The valve 22 preferably has a switching function capable of supplying the water supplied from the water pump 11 to the reformer 4 or the drainage pipe 23. For example, a three-way valve can be used.

  Here, when a predetermined time elapses after the water pump 11 is operated, almost all of the water remaining in the water supply pipe 5 connecting the water tank 10 and the water pump 11 is drained from the drain pipe 23. After the water remaining in the water supply pipe 5 connecting the water tank 10 and the water pump 11 is drained, the water sterilized water in the water tank 10 is supplied by the water pump 11. After draining the remaining water, it is preferable to control the valve 22 to close the drain pipe 23 so that the water stored in the water tank 10 is supplied to the reformer 4. That is, it is preferable that the control device 14 controls the valve 22 so as to close the drain pipe 23 after a predetermined time has elapsed since the water pump 11 was operated. Thereby, the water sterilized in the water tank 10 can be efficiently supplied to the reformer 4.

  It should be noted that after a predetermined time has elapsed since the water pump 11 was operated, it means that almost all of the water remaining in the water supply pipe 5 connecting the water tank 10 and the water pump 11 has been drained from the drain pipe 23. And can be set as appropriate according to the length and thickness of the water supply pipe 5 connecting the water tank 10 and the water pump 11, and further the water supply capacity of the water pump 11.

  With the configuration as described above, when the fuel cell device is started or restarted, the water supply pipe 5 for supplying water from the water tank 10 to the reformer 4 is clogged and the reformer 4 is prevented from being broken. Therefore, a fuel cell device with improved reliability can be obtained.

  Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the scope of the present invention.

  For example, in the case where the fuel cell apparatus is operated using only the condensed water generated in the heat exchanger 13 (that is, when each water treatment apparatus that supplies external water is not provided), the condensed water treatment apparatus 19 And the arrangement order of the water tanks 10 can be reversed.

  In this case, the control device 14 controls the operation of the heating unit 24 and the operation of the water pump 11 in consideration of the heat resistance of the condensed water treatment means (ion exchange resin or the like) included in the condensed water treatment device 19. It is preferable.

  Furthermore, the fuel cell device of the present invention is particularly useful when the fuel cell device is stopped for a long period of time, or when the time from the replenishment of pure water to the water tank 10 to the first startup becomes long. When the period is stopped, it can be set as appropriate based on the amount of water circulating in the fuel cell device, the size of the water tank 10, the outside air temperature, etc., and can be, for example, 3 days to 1 week or more. .

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

Explanation of symbols

1: Fuel cell (cell)
4: reformer 5: water supply pipe 10: water tank 11: water pump 13: heat exchanger 14: controller 19: condensed water treatment device 22: valve 23: drain pipe 24: heating unit

Claims (3)

  A fuel cell, a reformer for generating reformed gas to be supplied to the fuel cell, a water tank for storing water to be supplied to the reformer, and water stored in the water tank A fuel cell device comprising: a water supply pipe for leading to the reformer; and a water pump connected to the water supply pipe for supplying water stored in the water tank to the reformer, The water supply pipe between the reformer and the water pump has a drain pipe for draining water from the water supply pipe and a valve for opening and closing the drain pipe, and the water tank stores water in the water tank. A heating unit for heating the water, and when the fuel cell device is started, the heating unit heats the water stored in the water tank, and then operates the water pump, and the water pump Drain the water flowing through the water supply pipe for a predetermined time after the operation. Wherein to open the drainage pipe, the heating unit, the fuel cell system characterized by comprising a control device for controlling each of the water pump and the valve in order.   2. The fuel cell device according to claim 1, wherein the heating unit raises the water stored in the water tank to a temperature at which microorganisms contained in the water stored in the water tank can be heat sterilized. . 2. The fuel cell device according to claim 1, wherein the control device controls the valve so as to close the drain pipe after a predetermined time has elapsed since the water pump was operated.

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