JP2014026925A - Fuel cell device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell device that prevents wastewater from flowing backward to a condensed water tank through condensed water drain means.SOLUTION: An outer case 33 houses therein: a fuel cell 1; a heat exchanger 13; a condensed water tank 19 that stores condensed water produced by heat exchange in the heat exchanger 13; condensed water drain means 34 that is provided in the condensed water tank 19 and that drains the condensed water to the outside of the outer case 33 when the condensed water is at a predetermined level or higher; and a reformer 4. The condensed water drain means 34 has: a lead-out pipe 31 that is connected to the condensed water tank 19; a catch basin 37 that is connected to the lead-out pipe 31 and to which a hose 35 for leading the condensed water to the outside of the outer case 33 is coupled; and a bypass pipe 39 that is connected to a lower position in the catch basin 37 than a position where the lead-out pipe 31 of the condensed water tank 19 is connected and that opens outside the outer case 33.

Description

  The present invention relates to a condensate tank and a fuel cell device comprising a condensate drain means provided in the condensate tank.

  In recent years, as a next-generation energy, a fuel cell capable of obtaining electric power using hydrogen gas and an oxygen-containing gas (usually air) and auxiliary equipment for operating the fuel cell are installed in an outer case. Various fuel cell devices housed in the container have been proposed.

  Here, a steam reforming method is known as one of the methods for generating hydrogen necessary for power generation of a fuel cell, and a fuel cell device using this steam reforming generates fuel gas (hydrogen gas). Reformers, water treatment devices that produce pure water by processing water (such as tap water) supplied from outside, water tanks for temporarily storing the treated water (pure water), and water treatment It is known to include a water supply pipe or the like for connecting the apparatus, a water tank, and a reformer.

  In addition, a heat exchanger is provided for exchanging heat between the exhaust gas generated by the power generation of the fuel cell and water, and the condensed water generated by the heat exchange is stored in a condensed water tank, and the condensed water is pumped from this condensed water tank There is also known a fuel cell device that supplies a reformer via a gas (see, for example, Patent Document 1).

  When supplying condensed water generated by heat exchange to the reformer, the condensed water is a condensed water treatment means (device) such as an ion exchange resin in order to suppress (prevent) failure of the reformer and deterioration of the reforming catalyst. In some cases, after being treated in step (after being made pure water), it is supplied to the reformer.

  By the way, the amount of condensed water produced by heat exchange varies depending on the amount of exhaust gas, the temperature of water circulating in the heat exchanger, etc., so it is difficult to control the amount of produced water, and the fuel cell device is operated. Condensed water is continuously generated during this time. For this reason, condensate more than the volume of the condensate tank may be generated, and if the condensate is accumulated in the condensate tank more than a certain amount, the condensate is drained from the fuel cell device to the outside of the outer case via a drain hose. It is configured to be.

JP 2009-009808 A

  However, originally, when the amount of condensed water in the condensed water tank exceeds a certain level, the condensed water should be drained out of the outer case through the drainage hose, but the outlet opening of the drainage hose is flooded due to heavy rain. If the outlet opening is clogged, the sewage may flow backward through the drain hose. In this case, the condensed water tank is mixed with sewage, which may cause contamination.

  An object of this invention is to provide the fuel cell apparatus which can suppress that a sewage flows back into a condensed water tank via a condensed water drainage means.

The fuel cell device of the present invention includes a fuel cell, a heat exchanger for exchanging heat between the exhaust gas generated by power generation of the fuel cell and water, and condensed water generated by heat exchange in the heat exchanger. And a condensed water drain for draining condensed water to the outside of the outer case when the water level of the condensed water tank is equal to or higher than a predetermined water level. And a reformer that generates the reformed gas supplied to the fuel cell by steam reforming using the water in the condensed water tank, and the condensed water draining means includes the condensation A lead-out pipe connected to the water tank; a drainage tub connected to the lead-out pipe and connected to a hose for leading the condensed water out of the outer case; and the drainage basin, the lead-out pipe of the condensate water tank Than the position where the It is connected to the lower, characterized by comprising a bypass pipe which opens to the outside of the outer case.

  In the fuel cell device of the present invention, even if the outlet opening of the hose connected to the drainage is flooded with heavy rain or the like, or the outlet opening of the hose is clogged, and sewage flows back to the drainage via the hose. It can be discharged out of the outer case through the bypass pipe, and the sewage can be prevented from flowing back to the condensed water tank through the condensed water drainage means.

It is a block diagram which shows an example of a fuel cell system. (A) is a schematic diagram which shows the lower end part of a fuel cell apparatus, (b) is sectional drawing of a drain. It is sectional drawing of the form which provided the sensor in the vertically long drainage tub.

  FIG. 1 is a configuration diagram illustrating an example of a fuel cell system including a fuel cell device. This fuel cell system includes a power generation unit (fuel cell device) for generating power, a hot water storage unit for storing hot water after heat exchange, and a circulation pipe for circulating water between these units.

  A fuel cell system shown in FIG. 1 includes a fuel cell 1, a reformed gas supply means 2 for supplying a gas to be reformed such as natural gas and kerosene, and an oxygen-containing gas supply for supplying an oxygen-containing gas to the fuel cell 1. Means 3 is provided with a reformer 4 for steam reforming with a gas to be reformed and steam.

  Further, in the fuel cell system 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 a condensate that stores condensed water generated by the heat exchange. A condensed water recovery pipe 21 is provided for recovering (supplying) the condensed water generated in the water tank 19 and the heat exchanger 13 to the condensed water tank 19, and water stored in the condensed water tank 19 (condensed water). ) Is supplied to the reformer 4.

  On the other hand, when the amount of condensed water stored in the condensed water tank 19 is small, it is preferable to treat the water (such as tap water) supplied from the outside into pure water and supply it to the reformer 4. In 1, a water treatment device X is provided as means for treating the water supplied from the outside into pure water.

  Here, the water treatment device X includes an activated carbon filter device 7 for purifying water, a reverse osmosis membrane device 8 (hereinafter referred to as RO membrane device), and an ion exchange resin device for converting purified water into pure water. 9 devices are provided. The pure water generated by the ion exchange resin device 9 is stored in the water tank 10.

In addition, in FIG. 1, the example in the case of using together and using the water supplied from the outside, such as condensed water and tap water, is shown, and the condensed water tank 19 and the water tank 10 are the condensed water supply pipe | tube 20 (tank Connected by a connecting pipe). When only the condensed water is supplied to the reformer 4, the water supply valve 6
It is also possible to connect the condensate water tank 19 and the reformer 4 via a water pump. In addition, water supplied from the outside, such as tap water, is not used, that is, the water tank 10 and the water treatment device X can be eliminated.

  Further, in the fuel cell system shown in FIG. 1, a water supply pipe 5 that connects the activated carbon filter device 7, the RO membrane device 8, the ion exchange resin device 9, and the water tank 10 in this order is provided. 5 is provided with a water supply valve 6 for adjusting the amount of water supplied to the water supply pipe 5. In FIG. 1, the means for supplying water to the reformer 4 is shown surrounded by a one-dot chain line.

  Further, a power conditioner 12 for switching the DC power generated by the fuel cell 1 to AC power and supplying it to an external load, water provided at the outlet of the heat exchanger 13 (circulation water flow) flowing through the outlet of the heat exchanger 13 ) Includes an outlet water temperature sensor 15 for measuring the water temperature, a circulation pump 16 for circulating water, and a control device 14 for controlling the operation of the circulation pump 16 to constitute a power generation unit. The control device 14 will be described later.

  The hot water storage unit includes a hot water storage tank 18 for storing hot water after heat exchange, and a circulation pipe 17 for circulating water between the heat exchanger 13 and the hot water storage tank 18 is provided. It has been.

  Moreover, the arrows in the figure indicate the flow directions of fuel, oxygen-containing gas, and water. The same components are denoted by the same reference numerals, and so on. Although not shown, it is also possible to provide a reformed gas humidifier for humidifying the reformed gas between the reformed gas supply means 2 and the reformer 4.

  Various fuel cells are known as the fuel cell 1, but a solid oxide fuel cell can be used to reduce the size of the fuel cell. Thereby, in addition to the fuel cell, auxiliary machinery necessary for the operation of the fuel cell can be reduced in size, and the fuel cell device can be reduced in size. At the same time, it is possible to perform a load following operation that follows a fluctuating load required for a household fuel cell.

  As described above, the fuel cell device of the present invention is useful in a fuel cell device that performs steam reforming. In particular, a reformer 4 for performing steam reforming is disposed above the fuel cell 1, for example. This is optimal in a solid oxide fuel cell in which fuel that has not been used in the fuel cell 1 is burned to heat the reformer 4.

  As shown in FIG. 2A, the fuel cell device of the present embodiment includes a fuel cell 1, a reformer 4, a heat exchanger 13, a condensate water tank 19, A condensate drain means 34 provided in the condensate tank 19 for overflowing and draining the condensate out of the outer case 33 when the water level of the condensate tank 19 exceeds a predetermined level; Is contained.

  The condensed water draining means 34 is connected to the outlet pipe 31 connected to the condensed water tank 19, the drainage basin 37 connected to the outlet pipe 31, and the lower side of the drainage basin 37 where the outlet pipe 31 is connected. The bypass pipe 39 is provided.

  In addition, the bypass piping 39 should just be connected below the position where the outlet piping 31 of the condensed water tank 19 is connected in the drain 37.

The exterior case 33 is disposed with the foundation 41 placed on the ground, and the bottom surface of the exterior case 33 is located above the ground at a predetermined interval.

  The drainage basin 37 is connected to a hose 35 for extracting condensed water to the outside of the outer case 33 so that the condensed water from the hose 35 is discharged to an external drainage basin 45 connected to the sewer disposed on the ground. It is configured. For example, the hose 35 is connected to the drainage basin 37 after the fuel cell device is installed at a predetermined position. As shown in FIG. 2B, the drainage pipe 37 is provided with joint portions 31a, 35a, 39a so that the outlet pipe 31, the hose 35, and the bypass pipe 39 can be connected by a fixing jig or the like. Yes. Further, it is desirable that the bypass pipe 39 is provided with a filter. Thereby, invasion of insects or the like through the bypass pipe 39 can be suppressed.

  A water conductivity meter 42 is disposed in the condensed water tank 19, and the electrical conductivity of the condensed water in the condensed water tank 19 is measured to determine whether it can be used as reformed water. In addition, a sensor 40 that senses a rise in the water level in the drainage basin 37 is provided inside the drainage basin 37. The sensor 40 is a conductivity sensor or a float switch. The sensor 40 is configured such that when the water level reaches the position of the sensor 40, the electrical conductivity becomes high or the switch is turned on.

  The bypass pipe 39 is open to the bottom surface of the outer case 33, and is configured such that sewage flowing backward from the hose 35 is discharged to the space between the outer case 33 and the ground via the bypass pipe 39. Yes.

  In addition, the code | symbol 43 is an ion exchange resin apparatus, and the ion exchange resin apparatus 43 becomes unnecessary depending on the quality of condensed water.

  Here, an operation method of the fuel cell system shown in FIG. 1 will be described.

  The exhaust gas (exhaust heat) generated by the power generation of the fuel cell 1 is mainly used to increase or maintain the temperature of the fuel cell 1 and then supplied from the fuel cell 1 to the heat exchanger 13. In the heat exchanger 13, heat exchange is performed between the exhaust gas generated by the power generation of the fuel cell 1 and the water that flows (circulates) through the heat exchanger 13 (water that flows through the circulation pipe 17). The heat-exchanged water (hot water) is circulated through the circulation pipe 17 and stored in the hot water storage tank 18.

  On the other hand, the condensed water generated by heat exchange flows through the condensed water recovery pipe 21 and is stored in the condensed water tank 19. The condensed water stored in the condensed water tank 19 is processed by condensed water treatment means (not shown in FIG. 1) provided in the condensed water tank 19 or provided separately from the condensed water tank 19. Then, it flows through the condensed water supply pipe 20 and is supplied to the water tank 10. In FIG. 2 (a), the condensed water treatment means is shown as an ion exchange resin device 43, which is provided separately from the condensed water tank 19.

  In addition, as the condensed water processing means 43, what can be made into pure water by processing condensed water can be used. However, when the condensed water treatment means 43 is provided in the condensed water tank 19 or in replacement of the condensed water processing means. The ion exchange resin (hereinafter, the condensed water treatment means will be described as an ion exchange resin device and may be abbreviated as the ion exchange resin device 43) in consideration of the properties, the efficiency of the treatment of the condensed water, etc. For example, a spherical ion exchange resin can be used. The ion exchange resin device 43 can be appropriately provided depending on the purity of the condensed water, the size of the condensed water tank 19, the size of the ion exchange resin 23, and the like.

  The water stored in the water tank 10 is supplied to the reformer 4 by the water pump 11 according to the amount of water required by the reformer 4.

  In the reformer 4, steam reforming is performed by the water supplied by the water pump 11 and the gas to be reformed supplied from the gas to be reformed supply means 2. The reformed gas (fuel gas) generated in the reformer 4 is supplied to the fuel cell 1 and reacts with the oxygen-containing gas supplied from the oxygen-containing gas supply means 3 to generate power in the fuel cell 1. It is. The electric power generated by the power generation of the fuel cell 1 is supplied to an external load through the power conditioner 12.

  On the other hand, when supplying water (tap water or the like) supplied from the outside to the reformer 4, the water supply valve 6 is opened, and the water supplied from the outside through the water supply pipe 5 is activated carbon filter device. 7 is supplied with water. The water treated by the activated carbon filter device 7 is subsequently supplied to the RO membrane device 8. The water treated by the RO membrane device 8 is subsequently supplied and treated to the ion exchange resin device 9 to produce pure water. The pure water produced in the ion exchange resin device 9 is supplied to the water tank 10 and the condensed water is supplied to the reformer 4 according to the amount of water required in the reformer 4. The water pump 11 supplies the reformer 4 with the water.

  By using condensed water preferentially as the water supplied to the reformer 4, the amount of water supplied from the outside such as tap water can be reduced, and the running cost of the fuel cell device is reduced. be able to.

  In the fuel cell device configured as described above, the outlet opening of the hose 35 is located in the external drainage basin 45 installed on the ground. In such a state, the external drainage basin 45 is flooded due to heavy rain or the like. When the outlet opening of the hose 35 is clogged, it becomes difficult to drain the condensed water from the hose 35, and even when sewage flows back from the external drainage basin 45 into the drainage basin 37 via the hose 35, Sewage can be prevented from being discharged into the space between the outer case 33 and the ground via the bypass pipe 39 and entering the condensed water tank 19 via the outlet pipe 31.

  In addition, a sensor 40 is provided inside the drainage basin 37 to sense that the water level in the drainage basin 37 is higher than the connection position of the bypass pipe 39 with the drainage basin 37. When the water level of the sewage becomes higher than the connection position of the bypass pipe 39, the sensor 40 senses, and based on the signal from the sensor 40, the control device 14 Since it can be controlled to stop the fuel cell device, it can be stopped before the fuel cell device is submerged, and the fuel cell system can be stopped safely.

  That is, when the outlet opening of the bypass pipe 39 is submerged, in other words, when the bottom of the outer case 33 is submerged, dirty water enters and accumulates in the drain 37, and the water level is connected to the drain 37 of the bypass pipe 39. When the position is higher than the position, the control unit 14 can be controlled to stop the fuel cell system because there is a possibility that the fuel cell unit may be immersed in water, and the fuel cell system can be safely stopped.

  For example, as shown in FIG. 3, a vertically long drainage basin 37 is provided, and a water level sensor 51 capable of detecting the water level is provided therein, and operation control is performed according to the water level detected by the water level sensor 51. Can do.

In this case, for example, when the water level detected by the water level sensor 51 is low, the amount of air required for power generation is increased to lower the air utilization rate Ua, or the fuel gas required for power generation is decreased to reduce the fuel. Condensate generation is suppressed by increasing the utilization factor Uf, decreasing the ratio of water to carbon (S / C) supplied to the reformer, or decreasing the power generation output, while the water level sensor 51 When the water level detected in step S3 becomes high, it is possible to perform control to stop the operation of the fuel cell, and an optimal operation method is selected according to the water level detected by the water level sensor 51 in the drainage basin 37. Since various operation methods can be adopted until the operation is stopped, stable operation is possible.

  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.

1: Fuel cell 4: Reformer 10: Water tank 13: Heat exchanger 14: Control device 19: Condensate water tank 31: Outlet pipe 33: Exterior case 34: Condensate drainage means 35: Hose 37: Drainage tank 39: Bypass piping 40: Sensor 51: Water level sensor

Claims (4)

  In the outer case, a fuel cell, a heat exchanger that performs heat exchange between the exhaust gas generated by power generation of the fuel cell and water, a condensed water tank that stores condensed water generated by heat exchange in the heat exchanger, Condensate drainage means provided in the condensate tank for draining the condensate out of the outer case when the water level of the condensate tank is equal to or higher than a predetermined water level; And a reformer that generates water by reforming the reformed gas supplied to the fuel cell using steam, and the condensed water draining means is connected to the condensed water tank. A drainage basin connected to the lead-out pipe and connected to a hose for leading the condensed water out of the exterior case; and in the drainage basin, below the position where the lead-out pipe of the condensed water tank is connected Connected to the outside Fuel cell apparatus characterized by comprising a bypass pipe which opens into the outside of the case.   2. The fuel cell device according to claim 1, wherein the bypass pipe is connected to a position lower than a position where the outlet pipe is connected in the drainage basin.   The fuel cell apparatus according to claim 2, wherein a sensor for detecting an increase in the water level in the drainage basin is provided in the drainage basin.   The fuel cell device according to any one of claims 1 to 3, wherein a filter is provided inside the bypass pipe.

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