JP2010250949A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system that satisfies a drainage standard in a simple structure by reducing concentration of a carbon dioxide gas included in collected water collected from the fuel cell system and in the collected water obtained by condensing water vapor included in a combustion exhaust gas obtained by burning with a fuel gas producing device. <P>SOLUTION: A collected water tank 18 is formed by a first tank 18a divided with a partition plate 19 forming a gap 115 where the collected water passes through between the partition plate and a bottom of the collected water tank 18, and a second tank 18b having an exhaust port 110 ventilated with the atmosphere. After a fuel exhaust gas condensed water and collected water made of the fuel exhaust gas condensed water and a combustion exhaust gas condensed water are collected in the first tank 18a of the collected water tank 18, the collected water passes through to the second tank 18b bypassing the gap 115 between the partition plate 19 and the bottom of the collected water tank 18, and the collected water left over in the collected water tank 18 is discharged from the exhaust port 110 of the second tank 18b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell system.

  As a conventional fuel cell system, first, water vapor contained in the fuel exhaust gas discharged from the fuel cell and water vapor contained in the combustion exhaust gas obtained by burning at least one of the raw material gas and the fuel exhaust gas in the fuel gas generator Then, the recovered water obtained by condensing is temporarily stored in the recovered water tank. Thereafter, the recovered water tank is sent to an ion removing device by using a water supply means such as a pump, and the recovered water is deionized and used as water for generating hydrogen used for the fuel cell and its power generation. At that time, a configuration is disclosed in which excess recovered water is neutralized in a neutralization tank and then drained outside the fuel cell system (see, for example, Patent Document 1).

  Hereinafter, a conventional fuel cell system disclosed in Patent Document 1 will be described with reference to the drawings.

  FIG. 5 is a configuration diagram showing a conventional fuel cell system disclosed in Patent Document 1. As shown in FIG.

  As shown in FIG. 5, the fuel cell system 51 burns at least one of a fuel cell 52, an air supply device 53, a fuel gas generation device 54, a fuel exhaust gas condenser 56, and a raw material gas and a fuel exhaust gas. A combustion part 55 that performs combustion, a combustion exhaust gas condenser 57 that obtains combustion exhaust gas condensed water, a fuel exhaust gas condensed water condensed by the fuel exhaust gas condenser 56, and a recovered water tank 58 that stores the combustion exhaust gas condensed water as recovered water, It comprises a neutralization tank 59 for neutralizing the recovered water surplus in the tank 58.

  Here, the air supply device 53 supplies air to the fuel cell 52, and the fuel gas generation device 54 generates fuel gas to be supplied to the fuel cell 52. Further, the fuel exhaust gas condenser 56 condenses water vapor contained in the fuel exhaust gas discharged from the fuel cell 52 to generate fuel exhaust gas condensed water. Similarly, the combustion exhaust gas condenser 57 condenses water vapor contained in the combustion exhaust gas obtained by burning at least one of the raw material gas and the fuel exhaust gas in the fuel gas generation device 54 to generate combustion exhaust gas condensed water.

  Further, the neutralization tank 59 includes at least a bubbling device 511 for sending air to the recovered water and a neutralizing agent 512 for neutralizing the recovered water. Thereby, carbon dioxide gas is removed from the fuel exhaust gas condensed water and combustion exhaust gas condensed water containing a large amount of carbon dioxide gas, and the recovered water is neutralized by reducing the carbon dioxide concentration. At this time, tap water is sent to the neutralization tank 59, and the recovered water in the recovered water tank that has become excessive is drained from the drain outlet 510.

  In addition, as a conventional fuel cell system, first, a degassing device is disposed in a recovery path for water vapor contained in combustion exhaust gas, and carbon dioxide contained in recovered water obtained by condensing water vapor contained in combustion exhaust gas is removed in advance. After that, it is stored in the recovered water tank. Then, the recovered water tank is sent to an ion removing device using a water supply means such as a pump, and the recovered water is deionized to be used as water for generating hydrogen used for the fuel cell and its power generation. At that time, a configuration is disclosed in which excess recovered water is drained directly from the recovered water tank (see, for example, Patent Document 2).

  The conventional fuel cell system disclosed in Patent Document 2 will be described below with reference to the drawings.

  FIG. 6 is a configuration diagram showing a configuration of a conventional fuel cell system described in Patent Document 2. As shown in FIG.

  As shown in FIG. 6, the fuel cell system 61 combusts at least one of a fuel cell 62, an air supply device 63, a fuel gas generation device 64, a fuel exhaust gas condenser 66, and a raw material gas and a fuel exhaust gas. A combustion unit 65 that performs combustion, a combustion exhaust gas condenser 67 that obtains combustion exhaust gas condensed water, a deaeration device 69 that removes carbon dioxide contained in the combustion exhaust gas condensed water, a blower 611 that sends air to the deaeration device 69, It is composed of a flue gas condenser 67 and a recovered water tank 68 for storing the flue gas condensed water recovered by the deaerator 69 as recovered water.

  Here, the air supply device 63 supplies air to the fuel cell 62, and the fuel gas generation device 64 generates fuel gas to be supplied to the fuel cell 62. The fuel exhaust gas condenser 66 condenses water vapor contained in the fuel exhaust gas discharged from the fuel cell 62 to generate fuel exhaust gas condensed water. Similarly, the combustion exhaust gas condenser 67 condenses water vapor contained in the combustion exhaust gas obtained by burning at least one of the raw material gas and the fuel exhaust gas in the fuel gas generation device 64 to generate combustion exhaust gas condensed water.

JP 2004-172016 A JP 2005-129334 A

  However, in the fuel cell system described in Patent Document 1, it is necessary to dispose a neutralization tank that includes a bubbling device and a neutralizing agent, and thus there is a problem that the volume of the fuel cell system increases. It was. In addition, since it is necessary to introduce tap water and a neutralizing agent into the neutralization tank in order to neutralize the recovered water, the arrangement of the piping and the electromagnetic valve is complicated, and the control of the electromagnetic valve is complicated. There was a problem. Furthermore, when the neutralization process in the neutralization tank is incomplete, the pH of the drainage is lowered, and there is a problem that the drainage standard for draining into the sewer is not satisfied.

  Further, the fuel cell system described in Patent Document 2 has a problem that the volume of the fuel cell system increases because it is necessary to dispose a deaeration device. Further, in order to deaerate the recovered water, air that contacts the combustion exhaust gas condensed water is required in the deaeration device. Therefore, there existed a subject that arrangement | positioning of piping for addition of an air blower and sending air becomes complicated. Furthermore, when the deaeration process in the deaeration device is insufficient, the drainage water contains a large amount of carbon dioxide gas, so the pH of the drainage is lowered and the drainage standard (PH = 5.8 to 8.6) was not satisfied.

  The present invention solves the above-described conventional problems, and is included in the recovered water obtained by condensing the recovered water collected from the fuel cell system and the water vapor contained in the combustion exhaust gas obtained by combustion in the fuel gas generator. An object of the present invention is to provide a fuel cell system that satisfies the drainage standard with a simple configuration by reducing the concentration of carbon dioxide.

In order to solve the above conventional problems, the fuel cell system of the present invention includes a first tank partitioned by a partition plate that forms a gap through which the recovered water passes between the recovered water tank and the bottom surface of the recovered water tank. The second tank is provided with a drain port for venting to the atmosphere, and the recovered water comprising the fuel exhaust gas condensed water and the combustion exhaust gas condensed water is recovered in the first tank of the recovered water tank, and then the recovered water is separated from the partition plate. It is configured to pass only through the gap between the bottom of the recovered water tank and flow to the second tank, and to recover the excess recovered water in the recovered water tank from the drain port of the second tank. is there.

  Thereby, the recovered water containing a large amount of carbon dioxide gas recovered in the first tank is ventilated with the atmosphere through the drain port and is maintained in the atmospheric equilibrium. And since it fully dilutes with the collection | recovery water stored in the 2nd tank by which the carbon dioxide gas density | concentration was maintained low, the waste_water | drain with a low carbon dioxide gas density | concentration is drained through a drain outlet. As a result, it is possible to realize a fuel cell system that drains excess recovered water while satisfying the drainage standard.

  Further, the fuel cell system of the present invention includes a recovered water tank, a drain pipe provided with an on-off valve disposed on the bottom surface of the recovered water tank, an inlet port for receiving the recovered water disposed on the upper surface, and an opening for venting the atmosphere. And a water level sensor for detecting the level of water stored in the recovered water tank, and a control unit for controlling the open / close valve of the drain pipe, and is made up of fuel exhaust gas condensed water and combustion exhaust gas condensed water In addition to collecting the water from the inlet to the recovered water tank, the controller collects the recovered water remaining in the recovered water tank by receiving a signal from the water level sensor and controlling the drain pipe on / off valve in the control unit. Is.

  As a result, the recovered water containing a large amount of carbon dioxide gas recovered in the recovered water tank is aerated with the atmosphere through the opening, and is maintained in atmospheric equilibrium. And since it fully dilutes with the collection | recovery water stored in the collection | recovery water tank by which the carbon dioxide gas density | concentration was maintained low, the waste_water | drain with a low carbon dioxide gas density | concentration is drained through a drain pipe. As a result, it is possible to realize a fuel cell system that drains excess recovered water while satisfying the drainage standard.

  In the fuel cell system of the present invention, the recovered water tank has a water inlet disposed on the bottom surface of the recovered water tank and a drain port that vents to the atmosphere, and condenses the fuel exhaust gas and the combustion exhaust gas. The recovered water composed of water is collected from the water inlet to the recovered water tank, and the recovered water remaining in the recovered water tank is drained from the drain outlet.

  Thereby, the recovered water containing a large amount of carbon dioxide gas recovered in the recovered water tank is ventilated with the atmosphere through the drain port and is kept in the atmospheric equilibrium. And since it fully dilutes with the collection | recovery water stored in the collection | recovery water tank by which the carbon dioxide gas density | concentration was maintained low, the waste_water | drain with a low carbon dioxide gas density | concentration is drained through a drain outlet. As a result, it is possible to realize a fuel cell system that drains excess recovered water while satisfying the drainage standard.

  Further, by providing the water inlet on the bottom surface, the recovered water containing a large amount of carbon dioxide gas recovered in the recovered water tank is mixed with all the recovered water stored in the recovered water tank, so that the dilution effect is improved. Furthermore, since there is no need to divide the recovered water tank or arrange a water level sensor, the recovered water tank can be realized with a simple configuration.

  The fuel cell system of the present invention can reduce the concentration of carbon dioxide contained in the fuel exhaust gas condensate and combustion exhaust gas condensate recovered in the recovery water tank, and can realize a fuel cell system that satisfies the drainage standard with a simple configuration. .

1 is a configuration diagram showing a fuel cell system according to Embodiment 1 of the present invention. The block diagram which shows the fuel cell system in Embodiment 2 of this invention The block diagram which shows the fuel cell system in Embodiment 3 of this invention The block diagram which shows the fuel cell system in Embodiment 4 of this invention Configuration diagram showing a conventional fuel cell system Configuration diagram showing the configuration of a conventional fuel cell system

  A first invention is a fuel gas generation device that processes a raw material gas to generate a fuel gas containing hydrogen as a main component, a fuel cell that generates power using hydrogen in the fuel gas and oxygen in the air, A fuel cell system comprising at least a recovered water tank for storing recovered water, wherein the recovered water tank is partitioned by a partition plate that forms a gap through which the recovered water passes between the bottom surface of the recovered water tank. 1 tank and a 2nd tank provided with the drain which ventilates air | atmosphere, the water vapor | steam contained in the fuel exhaust gas discharged | emitted from a fuel cell, the raw material gas supplied to a fuel gas generator, fuel gas, and fuel exhaust gas The recovered water obtained by condensing water vapor contained in the flue gas obtained by burning at least one of the above is recovered in the first tank of the recovered water tank, and then passed through the gap to the second tank. Circulate and surplus in recovered water tank The recovered water is a fuel cell system to drain from the discharge port of the second tank.

  With this configuration, the recovered water containing a large amount of carbon dioxide gas recovered in the first tank is ventilated with the atmosphere through the drain and maintained in atmospheric equilibrium. And since it fully dilutes with the collection | recovery water stored in the 2nd tank by which the carbon dioxide gas density | concentration was maintained low, the waste_water | drain with a low carbon dioxide gas density | concentration is drained through a drain outlet. As a result, the pH of the drainage drained through the drainage port increases, and a fuel cell system that satisfies the drainage standard can be realized.

  According to a second aspect of the present invention, there is provided a fuel gas generation device that processes a raw material gas to generate a fuel gas containing hydrogen as a main component, a fuel cell that generates power using hydrogen in the fuel gas and oxygen in the air, A fuel cell system comprising at least a recovered water tank for storing recovered water, wherein the recovered water tank includes a drain pipe having an on-off valve disposed on a bottom surface of the recovered water tank, and a recovered water disposed on an upper surface. And a water level sensor that detects the level of water stored in the recovery water tank, and a control unit that controls the open / close valve of the drain pipe, and is discharged from the fuel cell. Recovery obtained by condensing water vapor contained in fuel exhaust gas, raw material gas supplied to the fuel gas generator, and water vapor contained in combustion exhaust gas obtained by burning at least one of fuel gas and fuel exhaust gas Add water Is recovered from the mouth, the recovered water became excessive in the recovered water tank, a fuel cell system for draining by controlling the opening and closing valve of the drain pipe at the control unit receives a signal from the water level sensor.

  With this configuration, the recovered water containing a large amount of carbon dioxide gas recovered in the recovered water tank is aerated with the atmosphere through the opening and is kept in atmospheric equilibrium. And since it fully dilutes with the collection | recovery water stored in the collection | recovery water tank by which the carbon dioxide gas density | concentration was maintained low, the waste_water | drain with a low carbon dioxide gas density | concentration is drained through a drain pipe. As a result, the pH of the drainage drained through the drain pipe increases, and a fuel cell system that satisfies the drainage standard can be realized.

  According to a third aspect of the present invention, there is provided a fuel gas generating device that processes a raw material gas to generate a fuel gas mainly composed of hydrogen, a fuel cell that generates power using hydrogen in the fuel gas and oxygen in the air, A fuel cell system comprising at least a tank for storing recovered water, the recovered water tank having a water inlet disposed on a bottom surface of the recovered water tank, and a drain port for venting air to the fuel cell. Water vapor contained in the fuel exhaust gas discharged from the fuel gas and the water vapor contained in the combustion exhaust gas obtained by burning at least one of the raw material gas, fuel gas and fuel exhaust gas supplied to the fuel gas generator The fuel cell system collects the recovered water obtained from the water inlet and drains the recovered water remaining in the recovered water tank from the drain outlet.

With this configuration, the recovered water containing a large amount of carbon dioxide gas recovered in the recovered water tank is ventilated with the atmosphere through the drain and maintained in atmospheric equilibrium. And since it fully dilutes with the collection | recovery water stored in the collection | recovery water tank by which the carbon dioxide gas density | concentration was maintained low, the waste_water | drain with a low carbon dioxide density | concentration is drained through a drain outlet. As a result, the pH of the drainage drained through the drainage port increases, and a fuel cell system that satisfies the drainage standard can be realized. Further, by providing the water inlet on the bottom surface, the recovered water containing a large amount of carbon dioxide gas recovered in the recovered water tank is mixed with all the recovered water stored in the recovered water tank, so that the dilution effect is improved. Furthermore, since there is no need to divide the recovered water tank or arrange a water level sensor, the recovered water tank can be realized with a simple configuration.

  A fourth invention is the fuel cell system according to the first invention, wherein the first tank has an opening for ventilating with the atmosphere at a position higher than the drain outlet of the second tank. Thereby, since the recovered water stored in the first tank is maintained in atmospheric equilibrium through the opening, the carbon dioxide concentration of the recovered water can be more effectively diluted. As a result, the concentration of carbon dioxide gas in the waste water can be further reduced, the pH of the waste water can be reliably maintained within the drainage standard, and excess recovered water can be drained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the same reference numerals are given to the same configurations as the conventional configurations described above, and the detailed description thereof will be omitted. The present invention is not limited to the embodiments.

(Embodiment 1)
Hereinafter, the fuel cell system according to Embodiment 1 of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram showing a fuel cell system according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the fuel cell system 11 includes a recovered water tank 18 that stores recovered water, an ion removing device 113 that deionizes the recovered water supplied from the recovered water tank 18 into deionized water, A water pump 114 that supplies the recovered water from the water tank 18 to the ion removing device 113, and a fuel gas mainly composed of hydrogen by reforming the city gas that is a raw material gas by receiving the supply of deionized water from the water pump 114. A fuel gas generation device 14 to be generated, an air supply device 13 for supplying air to the fuel cell 12, and a fuel cell that generates power using the fuel gas supplied from the fuel gas generation device 14 and the air supplied from the air supply device 13 12, a fuel exhaust gas / fuel gas condenser 16 for condensing water vapor contained in the fuel exhaust gas discharged from the fuel cell 12 to obtain fuel exhaust gas condensed water, and a fuel exhaust gas / fuel A fuel exhaust gas / fuel gas condensate flow path 111 for guiding the fuel exhaust gas condensed water condensed in the gas condenser 16 to the recovered water tank 18 and at least one of the raw material gas, the fuel gas, and the fuel exhaust gas disposed in the fuel gas generator 14. Combustion exhaust gas obtained by combusting at least one of the raw material gas, the fuel gas and the fuel exhaust gas by the combustion unit 15 that burns one gas and the fuel gas generator 14 to obtain the combustion exhaust gas condensed water The combustion exhaust gas condenser 17 and the combustion exhaust gas condensed water flow path 112 that guides the combustion exhaust gas condensed water condensed by the combustion exhaust gas condenser 17 to the recovered water tank 18 are configured.

  Further, the recovered water tank 18 of the present embodiment includes a drain port 110 and a partition plate 19 for draining excess recovered water stored in the recovered water tank 18. The partition plate 19 is attached to, for example, the upper surface of the recovered water tank 18 so as to partition the recovered water tank 18 into the first tank 18a and the second tank 18b, and downwards with the bottom surface of the recovered water tank 18. A gap 115 through which the recovered water passes is provided between them. At this time, the vertical length of the partition plate 19 is adjusted so that at least the gap 115 is provided below the position where the recovered water begins to flow out from the drain port 110.

  Below, the material of the component which comprises the fuel cell system 11, and its effect | action are demonstrated concretely.

First, the recovered water tank 18 is made of, for example, stainless steel or resin, and the recovered water is stored therein. The ion removing device 113 is filled with, for example, an ion exchange resin that adsorbs cations and anions in condensed water and deionizes the condensed water to generate deionized water in a container made of stainless steel or resin. Has been.

  Further, in the fuel gas generator 14, a container made of, for example, stainless steel is filled with a catalyst having ruthenium supported on an alumina carrier. Then, the city gas and the deionized water supplied via the ion removing device 113 are chemically reacted at about 650 ° C. to generate hydrogen and carbon dioxide. At this time, the deionized water supplied from the ion removing device 113 has a role of causing the chemical reaction to proceed.

  The fuel gas generator 14 further includes a catalyst having platinum supported on an alumina carrier on the downstream side to oxidize a small amount of carbon monoxide generated by a chemical reaction into carbon dioxide. For example, selective oxidation means, etc. have.

  In addition, the fuel cell 12 has catalyst platinum particles on carbon black on both sides of a polymer-based hydrogen ion conductive electrolyte membrane (not shown) in which a sulfone side chain is attached to the main chain of fluorocarbon. It is comprised from the aggregate | assembly which laminated | stacked the battery provided with the fuel electrode and air electrode (not shown) which carried and comprised. Then, power is generated by an electrochemical reaction between hydrogen in the fuel gas supplied from the fuel gas generation device 14 to the fuel electrode and oxygen in the air supplied from the air supply device 13 to the air electrode.

  The fuel gas generator 14 is provided with a combustion unit 15. The combustion unit 15 burns city gas, which is a raw material gas, at the start of operation of the fuel cell system 11, and burns hydrogen in the fuel gas discharged without being used by the fuel cell 12 in stable operation. .

  Below, the operation | movement operation | movement of the fuel cell system 11 of this Embodiment is demonstrated.

  First, at the start of operation, city gas as raw material gas from a gas supply pipe (not shown) and air from a blower (not shown) are supplied to the combustion section 15 and combustion starts to obtain fuel gas. . The fuel gas is sent to the fuel exhaust gas / fuel gas condenser 16 through the bypass passage 116. The fuel gas sent to the fuel exhaust gas / fuel gas condenser 16 is sent to the combustion unit 15 after the water vapor contained therein is condensed in the fuel exhaust gas / fuel gas condenser 16. In the fuel gas generation device 14, the combustion exhaust gas obtained by burning the city gas, the fuel gas, or the fuel exhaust gas is sent to the combustion exhaust gas condenser 17 disposed in the combustion exhaust gas flow path, and the water vapor contained in the combustion exhaust gas Is condensed and flows into the first tank 18a of the recovered water tank 18 as combustion exhaust gas condensed water and recovered.

  At the same time, the combustion unit 15 heats the catalyst filled in the fuel gas generator 14 to about 650 ° C.

  When the catalyst of the fuel gas generation device 14 is heated to about 650 ° C., the fuel gas generation device 14 performs the following two-stage operation.

  First, the fuel gas generation device 14 performs, for example, a reforming reaction between deionized water supplied from the water pump 114 via the ion removal device 113 and city gas supplied from a gas supply pipe (not shown). Thus, a fuel gas mainly containing hydrogen is generated.

Next, the fuel cell 12 generates power by an electrochemical reaction between hydrogen in the fuel gas supplied from the fuel gas generation device 14 and oxygen in the air supplied from the air supply device 13. And the fuel exhaust gas discharged | emitted without being used with the fuel cell 12 is supplied to the combustion part 15 of the fuel gas production | generation apparatus 14, and combustion of a fuel exhaust gas occurs. At this time, the fuel exhaust gas from the fuel cell 12 supplied to the combustion unit 15 of the fuel gas generator 14 is converted into water vapor contained in the fuel exhaust gas by the fuel exhaust gas / fuel gas condenser 16 disposed in the middle of the flow path. Is removed and supplied to the combustion section 15. By removing the water vapor, the fuel exhaust gas having a small water content is combusted in the combustion unit 15 to realize stable combustion without generating soot.

  Hereinafter, the flow of recovered water in the fuel cell system 11 of the present embodiment will be described.

  First, as shown in FIG. 1, the fuel exhaust gas / fuel gas condenser 16 disposed in the fuel exhaust gas flow path from the fuel cell 12 condenses water vapor contained in the fuel exhaust gas discharged from the fuel cell 12 so as to condense the fuel exhaust gas. Condensed water is obtained. The obtained fuel exhaust gas condensed water is sent as recovered water to the first tank 18 a of the recovered water tank 18 via the fuel exhaust gas / fuel gas condensed water flow path 111.

  On the other hand, the water vapor contained in the fuel gas sent to the fuel exhaust gas / fuel gas condenser 16 through the bypass passage 116 is condensed in the fuel exhaust gas / fuel gas condenser 16 and passes through the fuel exhaust gas / fuel gas condensed water passage 111. The fuel gas condensed water is sent to the first tank 18 a of the recovered water tank 18. Further, the combustion exhaust gas obtained by burning at least one of the raw material gas, the fuel gas, and the fuel exhaust gas in the fuel gas generation device 14 by the combustion exhaust gas condenser 17 disposed in the combustion exhaust gas flow path from the fuel gas generation device 14. Condensed exhaust gas is obtained by condensing the water vapor contained in the gas. The obtained flue gas condensed water is sent as recovered water to the first tank 18a of the recovered water tank 18 through the flue gas condensed water flow path 112.

  Further, the recovered water composed of the fuel exhaust gas condensed water, the fuel gas condensed water, and the fuel exhaust gas condensed water sent to the first tank 18 a of the recovered water tank 18 is a gap between the partition plate 19 and the bottom surface of the recovered water tank 18. The water passes through 115 and is passed through the second tank 18 b of the recovered water tank 18.

  And the recovered water which became surplus exceeding predetermined amount is drained from the drain 110 arranged in the 2nd tank 18b. Here, the predetermined amount of recovered water can maintain the normal operation of the fuel cell system. For example, in the case of the fuel cell system of the present embodiment, it is about 1 liter. For this reason, at least the drain outlet is provided at a position higher than the position of the recovered water tank for storing a predetermined amount of recovered water.

  At this time, the partition plate 19 can prevent the exhaust gas condensate containing high-concentration carbon dioxide gas, the recovered water comprising the fuel gas condensate and the combustion exhaust gas condensate from being discharged directly from the drain port.

  Also, the recovered water consisting of the fuel exhaust gas condensate containing high-concentration carbon dioxide gas, the fuel gas condensate and the combustion exhaust gas condensate is mixed with the recovered water stored in the first layer of the recovery water tank. And can be discharged with a reduced concentration of carbon dioxide. This is because the recovered water stored in the recovered water tank is in contact with the atmosphere through the drain port provided in the second layer, so that the concentration of carbon dioxide gas decreases due to atmospheric equilibrium. This is because recovered water containing a high concentration of can be diluted by mixing.

  Next, the recovered water stored in the second tank 18 b of the recovered water tank 18 is sent to the ion removing device 113 by the water pump 114, deionized, and then supplied to the fuel gas generating device 14.

  As described above, according to the fuel cell system of the embodiment of the present invention, the recovered water is recovered in the first tank of the recovered water tank, and then passes through the gap between the partition plate and the bottom surface of the recovered water tank. Then, by allowing the water to flow through the second tank, the recovered water containing a large amount of carbon dioxide gas can be aerated with the atmosphere and kept in the atmospheric equilibrium. Moreover, the recovered water containing the high concentration carbon dioxide gas can be sufficiently diluted with the recovered water stored in the recovered water tank in which the carbon dioxide concentration is kept low. As a result, since the waste water having a reduced carbon dioxide concentration can be drained from the drain port, it is possible to realize a fuel cell system capable of draining while maintaining the drainage pH at the drainage standard.

  In addition, although this Embodiment demonstrated in the example in which the 1st tank partitioned off with the partition plate of the collection | recovery water tank was comprised by closed space, it is not restricted to this. For example, you may provide the 1st tank with the opening part which ventilates air | atmosphere in the position higher than the drain outlet of a 2nd tank. Thereby, the collected water stored in the first tank can be maintained in atmospheric equilibrium without flowing through the second layer, and the carbon dioxide concentration of the collected water stored in the first tank can be reduced. Moreover, the dilution effect of the recovered water which consists of fuel exhaust gas condensed water, fuel gas condensed water, and combustion exhaust gas condensed water can be heightened more. As a result, the carbon dioxide gas concentration in the wastewater can be reduced in a short time, so that the pH of the wastewater can be more reliably maintained at the drainage standard.

  Further, in the present embodiment, the example in which the partition plate is configured by providing a gap between the bottom surface of the recovered water tank has been described, but the present invention is not limited thereto. For example, the partition plate is arranged without providing a gap between the bottom surface of the recovered water tank, a through hole is provided near the bottom surface of the partition plate, and only the through hole through which the recovered water recovered in the first tank passes is passed. It is good also as a structure which lets water flow to a 2nd tank, and the same effect is acquired.

  Moreover, although this Embodiment demonstrated the structure which attached the partition plate to the upper surface of the collection | recovery water tank as an example, it is not restricted to this. For example, if the surface of the recovered water recovered in the first layer is in contact with the atmosphere of the second layer, a through hole is provided in the partition plate so that the space between the first layer and the second layer is connected. May be. Thereby, the recovered water recovered in the first layer can be ventilated with the atmosphere and kept in the atmospheric equilibrium.

  Hereinafter, specific effects of the fuel cell system 11 in the present embodiment will be described.

  First, in the fuel cell system 11 having the configuration of the present embodiment, when the operation is continued in the power generation state of 1 kW, evaluation is performed from the concentration of carbon dioxide contained in the drainage discharged from the drain outlet of the second layer of the recovered water tank and the PH. did. As a result, the carbon dioxide gas concentration of the wastewater was 2.0 mg / L, and the pH of the wastewater was 6.2.

  On the other hand, for comparison, the same evaluation was performed with a fuel cell system including a recovered water tank without a partition plate. As a result, the carbon dioxide gas concentration in the wastewater was 15.0 mg / L, and the pH of the wastewater was 4.9.

  From the above, the drainage discharged from the recovered water tank of the fuel cell system according to the present embodiment sufficiently satisfies the drainage standard (PH = 5.8 to 8.6) compared to the drainage of the conventional fuel cell system. I found it to satisfy.

(Embodiment 2)
The fuel cell system according to Embodiment 2 of the present invention will be described below with reference to the drawings.

  FIG. 2 is a configuration diagram showing a fuel cell system according to Embodiment 2 of the present invention. In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof may be omitted.

  That is, as shown in FIG. 2, the fuel cell system 21 of the present embodiment includes a first recovered water tank 22 and a second recovered water tank provided with a drain port 25 for draining excess recovered water. 23, and the first recovered water tank 22 and the second recovered water tank 23 are connected by a connecting pipe 24 provided on the bottom surface of the first recovered water tank 22 and the second recovered water tank 23. Different from the recovered water tank consisting of the second tank. Since other components and their operations are the same as those in the first embodiment, description thereof is omitted.

  The first recovered water tank 22, the second recovered water tank 23, and the connecting pipe 24 are made of, for example, stainless steel or resin.

  Hereinafter, the flow of recovered water, which is the point of the invention of the fuel cell system 21 of the present embodiment, will be described.

  As shown in FIG. 2, the recovered water composed of the fuel exhaust gas condensed water, the fuel gas condensed water and the combustion exhaust gas condensed water is first recovered in the first recovered water tank 22 and then through the connecting pipe 24 to the second recovered water tank. 23 is passed through. At this time, the excess recovered water exceeding the predetermined amount is drained from the drain port 25 arranged in the second recovered water tank 23.

  The recovered water stored in the second recovered water tank 23 is sent to the fuel gas generating device 14 via the ion removing device 113 by the water pump 114.

  At this time, by separating the first recovered water tank, the second recovered water tank, and the recovered water tank, recovered water comprising fuel exhaust gas condensed water, fuel gas condensed water, and combustion exhaust gas condensed water containing high-concentration carbon dioxide gas. However, it can prevent discharging directly from the drain port of the second recovery water tank.

  In addition, recovered water composed of fuel exhaust gas condensate or combustion exhaust gas condensate containing high-concentration carbon dioxide gas is diluted by mixing with the recovered water stored in the first recovery water tank, and the carbon dioxide gas The concentration can be lowered and flowed to the second recovered water tank. This is because the recovered water stored in the first recovered water tank comes into contact with the atmosphere through the drain port provided in the second recovered water tank connected by the connecting pipe 24, so that the concentration of carbon dioxide gas is increased to the atmosphere. This is because the water is reduced due to the equilibrium, and the recovered water containing carbon dioxide at a high concentration can be diluted by mixing.

  As described above, according to the fuel cell system of the embodiment of the present invention, the recovered water is collected in the first recovered water tank, and then the recovered water is passed through the connecting pipe to the second recovered water tank. The recovered water containing a large amount of carbon dioxide gas can be kept in atmospheric equilibrium by aeration with the atmosphere. Further, it can be sufficiently diluted with the recovered water stored in the second recovered water tank in which the carbon dioxide concentration is kept low. As a result, since the waste water having a reduced carbon dioxide concentration can be drained from the drain port, it is possible to realize a fuel cell system capable of draining while maintaining the drainage pH at the drainage standard.

  In addition, in this Embodiment, although the 1st collection | recovery water tank demonstrated in the example comprised by closed space, it is not restricted to this. For example, an opening for venting to the atmosphere may be provided in the first recovered water tank at a position higher than the drain port of the second recovered water tank. Accordingly, the recovered water stored in the first recovered water tank can be kept in atmospheric equilibrium without flowing through the second recovered water tank, and the concentration of carbon dioxide in the recovered water stored in the first recovered water tank can be reduced. . Moreover, the dilution effect of the recovered water which consists of fuel exhaust gas condensed water, fuel gas condensed water, and combustion exhaust gas condensed water can be heightened more. As a result, the carbon dioxide gas concentration in the wastewater can be reduced in a short time, so that the pH of the wastewater can be more reliably maintained at the drainage standard.

  Hereinafter, specific effects of the fuel cell system 21 in the present embodiment will be described.

  First, the fuel cell system 21 having the configuration of the present embodiment was evaluated from the concentration of carbon dioxide contained in the drainage discharged from the drain of the second recovery water tank and the PH when the operation was continued in the power generation state of 1 kW. As a result, the carbon dioxide gas concentration of the wastewater was 2.0 mg / L, and the pH of the wastewater was 6.2.

  On the other hand, for comparison, a similar evaluation was performed using a fuel cell system including one recovered water tank. As a result, the carbon dioxide gas concentration in the wastewater was 15.0 mg / L, and the pH of the wastewater was 4.9.

  From the above, the drainage discharged from the recovered water tank of the fuel cell system according to the present embodiment sufficiently satisfies the drainage standard (PH = 5.8 to 8.6) compared to the drainage of the conventional fuel cell system. I found it to satisfy.

(Embodiment 3)
The fuel cell system according to Embodiment 3 of the present invention will be described below with reference to the drawings.

  FIG. 3 is a configuration diagram showing a fuel cell system according to Embodiment 3 of the present invention. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof may be omitted.

  That is, as shown in FIG. 3, the fuel cell system 31 of the present embodiment has a drain pipe 32 disposed on the bottom surface, a water inlet 37 disposed on the top surface, and an opening for venting the atmosphere in the recovered water tank 38. And a water level sensor 35 for detecting the level of the recovered water stored in the recovered water tank 38. Further, the drain pipe 32 has a control device 34 that receives the signal from the water level sensor 35, specifically an electrical signal, for controlling the open / close state of the open / close valve 33. This is different from the first embodiment. Since other components and their operations are the same as those in the first embodiment, description thereof is omitted.

  The recovered water tank 38, the drain pipe 32, and the water level sensor 35 are made of, for example, stainless steel or resin.

  Below, the driving | running operation | movement of the fuel cell system 31 of this Embodiment is demonstrated.

  First, at the start of operation, city gas as raw material gas from a gas supply pipe (not shown) and air from a blower (not shown) are supplied to the combustion section 15 and combustion starts to obtain fuel gas. . The fuel gas is sent to the fuel exhaust gas / fuel gas condenser 16 through the bypass passage 116. The fuel gas sent to the fuel exhaust gas / fuel gas condenser 16 is sent to the combustion unit 15 after the water vapor contained therein is condensed in the fuel exhaust gas / fuel gas condenser 16. In the fuel gas generation device 14, the combustion exhaust gas obtained by burning the city gas or the fuel gas is sent to the combustion exhaust gas condenser 17 arranged in the combustion exhaust gas flow path, and the water vapor contained in the combustion exhaust gas is condensed. The combustion exhaust gas condensed water flows from the water inlet 37 of the recovered water tank 38 and is recovered.

  At the same time, the combustion unit 15 heats the catalyst filled in the fuel gas generator 14 to about 650 ° C.

  When the catalyst of the fuel gas generation device 14 is heated to about 650 ° C., the fuel gas generation device 14 performs the following two-stage operation.

First, the fuel gas generation device 14 performs, for example, a reforming reaction between deionized water supplied from the water pump 114 via the ion removal device 113 and city gas supplied from a gas supply pipe (not shown). Thus, a fuel gas mainly containing hydrogen is generated.

  Next, the fuel cell 12 generates power by an electrochemical reaction between hydrogen in the fuel gas supplied from the fuel gas generation device 14 and oxygen in the air supplied from the air supply device 13. And the fuel exhaust gas discharged | emitted without being used with the fuel cell 12 is supplied to the combustion part 15 of the fuel gas production | generation apparatus 14, and combustion of a fuel exhaust gas occurs. At this time, the fuel exhaust gas from the fuel cell 12 supplied to the combustion unit 15 of the fuel gas generator 14 is converted into water vapor contained in the fuel exhaust gas by the fuel exhaust gas / fuel gas condenser 16 disposed in the middle of the flow path. Is removed and supplied to the combustion section 15. By removing the water vapor, the fuel exhaust gas having a small water content is combusted in the combustion unit 15 to realize stable combustion without generating soot.

  Hereinafter, the flow of recovered water, which is a point of the fuel cell system 31 of the present embodiment, will be described.

  First, as shown in FIG. 3, the fuel exhaust gas / fuel gas condenser 16 disposed in the fuel exhaust gas flow path from the fuel cell 12 condenses water vapor contained in the fuel exhaust gas discharged from the fuel cell 12 so as to condense the fuel exhaust gas. Condensed water is obtained. The obtained fuel exhaust gas condensed water is sent as recovered water from the water inlet 37 to the recovered water tank 38 via the fuel exhaust gas / fuel gas condensed water flow path 111. On the other hand, the water vapor contained in the fuel gas sent to the fuel exhaust gas / fuel gas condenser 16 through the bypass passage 116 is condensed in the fuel exhaust gas / fuel gas condenser 16 and passes through the fuel exhaust gas / fuel gas condensed water passage 111. The fuel gas condensed water is sent to the first tank 18 a of the recovered water tank 18. Further, the combustion exhaust gas obtained by burning at least one of the raw material gas, the fuel gas, and the fuel exhaust gas in the fuel gas generation device 14 by the combustion exhaust gas condenser 17 disposed in the combustion exhaust gas flow path from the fuel gas generation device 14. Condensed exhaust gas is obtained by condensing the water vapor contained in the gas. The obtained combustion exhaust gas condensed water is sent as recovered water from the water inlet 37 to the recovered water tank 38 via the combustion exhaust gas condensed water flow path 112. At this time, the level of the recovered water in the recovered water tank 38 rises as the recovered water composed of the fuel exhaust gas condensed water, the fuel gas, and the combustion exhaust gas condensed water is stored in the recovered water tank 38.

  When the water level of the recovered water exceeds the predetermined upper limit water level set by the water level sensor 35, an electrical signal is received from the water level sensor 35, the control device 34 opens the on-off valve 33, and the recovered water tank 38 is opened. The collected recovered water is drained from the drain pipe 32. Thereby, the level of the recovered water in the recovered water tank 38 is lowered.

  On the other hand, when the water level of the recovered water becomes lower than the predetermined lower limit water level set by the water level sensor 35, the electrical signal from the water level sensor 35 is received, the control device 34 closes the on-off valve 33, and the recovered water tank 38 The recovered water is stored inside. That is, by switching the open / close state of the on-off valve 33 based on the information of the water level sensor 35, a predetermined amount of recovered water is maintained and stored in the recovered water tank 38.

  Next, the recovered water stored in the recovered water tank 38 is sent to the fuel gas generating device 14 via the ion removing device 113 by the water pump 114.

  At this time, the concentration of the carbon dioxide gas recovered from the fuel exhaust gas condensate containing the high-concentration carbon dioxide gas and the fuel gas and the combustion exhaust gas condensate recovered in the recovery water tank passes through the opening of the recovery water tank. It decreases due to atmospheric equilibrium when it comes into contact with the atmosphere. Also, recovered water containing high-concentration carbon dioxide gas is sufficiently diluted by mixing with recovered water stored in the recovered water tank until the upper limit is detected by the water level sensor and discharged from the drain pipe. The

  As described above, according to the fuel cell system of the embodiment of the present invention, the combustion exhaust gas condensate containing a large amount of carbon dioxide gas and the recovered water composed of the fuel gas and the fuel exhaust gas condensate are collected from the atmosphere through the opening. Aeration can be maintained at atmospheric equilibrium. Further, it can be sufficiently diluted with the recovered water stored in the recovered water tank where the carbon dioxide gas concentration is kept low. As a result, since the waste water having a reduced carbon dioxide concentration can be drained from the drain pipe, a fuel cell system capable of draining while maintaining the pH of the waste water at the drainage standard can be realized.

  Hereinafter, specific effects of the fuel cell system 31 in the present embodiment will be described.

  First, the fuel cell system 31 having the configuration of the present embodiment was evaluated from the concentration of carbon dioxide contained in the wastewater drained from the drain pipe of the recovered water tank and the PH when the operation was continued in the power generation state of 1 kW. As a result, the carbon dioxide gas concentration of the wastewater was 2.0 mg / L, and the pH of the wastewater was 6.2.

  On the other hand, for comparison, the same evaluation was performed with a fuel cell system including a recovered water tank without an opening. As a result, the carbon dioxide gas concentration in the wastewater was 15.0 mg / L, and the pH of the wastewater was 4.9.

  From the above, the drainage discharged from the recovered water tank of the fuel cell system according to the present embodiment sufficiently satisfies the drainage standard (PH = 5.8 to 8.6) compared to the drainage of the conventional fuel cell system. I found it to satisfy.

(Embodiment 4)
The fuel cell system according to Embodiment 4 of the present invention will be described below with reference to the drawings.

  FIG. 4 is a configuration diagram showing a fuel cell system 41 according to Embodiment 4 of the present invention. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof may be omitted.

  That is, as shown in FIG. 4, the fuel cell system 41 of the present embodiment removes the partition plate, and also has a fuel exhaust gas / fuel gas condensate water channel 43 and a combustion exhaust gas condensate water channel 44 on the bottom surface of the recovered water tank 46. It differs from Embodiment 1 by the point which provided the water inlet 45 connected. Since other components and their operations are the same as those in the first embodiment, description thereof is omitted.

  As shown in FIG. 4, surplus recovered water out of the recovered water recovered in the recovered water tank 46 is drained from the drain port 42.

  Hereinafter, the flow of recovered water, which is the point of the invention of the fuel cell system 41 of the present embodiment, will be described.

  As shown in FIG. 4, the recovered water comprising the fuel exhaust gas condensed water, the fuel gas, and the combustion exhaust gas condensed water is first recovered from the water inlet 45 through the fuel exhaust gas / fuel gas condensed water channel 43 and the combustion exhaust gas condensed water channel 44. It is collected in the water tank 46.

  The surplus recovered water exceeding a predetermined amount is drained from a drain outlet 42 disposed in the recovered water tank 46.

At this time, the recovered water composed of the fuel exhaust gas condensed water and the combustion exhaust gas condensed water containing high-concentration carbon dioxide gas flowing from the water inlet provided on the bottom surface of the recovered water tank 46 is the recovered water stored in the recovered water tank. It is diluted by mixing. Further, the recovered water stored in the recovered water tank 46 comes into atmospheric equilibrium through contact with the atmosphere via the drain port 42 provided in the recovered water tank 46, and the concentration of carbon dioxide gas decreases. As a result, when the recovered water that has become surplus is discharged from the drain outlet, it can be drained in a state where the concentration of carbon dioxide gas is sufficiently lowered.

  Next, the recovered water stored in the recovered water tank 46 is sent to the fuel gas generator 14 by the water pump 114 via the ion removing device 113.

  As explained above, according to the fuel cell system of the embodiment of the present invention, the combustion exhaust gas condensate containing a large amount of carbon dioxide gas and the recovered water comprising the fuel gas and the fuel exhaust gas condensate are provided on the bottom surface of the recovery water tank. By collecting the water from the water inlet, the air is aerated with the atmosphere through the water outlet while the water is stored up to the water outlet. Moreover, it can dilute by mixing with the collection | recovery water collect | recovered previously. As a result, since the waste water having a reduced carbon dioxide concentration can be drained from the drain port, a fuel cell system capable of draining while maintaining the pH of the waste water at the drainage standard can be realized.

  Hereinafter, specific effects of the fuel cell system 41 in the present embodiment will be described.

  First, the fuel cell system 41 having the configuration of the present embodiment was evaluated from the concentration of carbon dioxide contained in the wastewater drained from the drain pipe of the recovered water tank and the PH when the operation was continued in the 1 kW power generation state. As a result, the carbon dioxide gas concentration of the wastewater was 2.0 mg / L, and the pH of the wastewater was 6.2.

  On the other hand, for comparison, the same evaluation was performed with a fuel cell system including a recovered water tank that recovers recovered water from a water inlet provided on the upper surface of the recovered water tank. As a result, the carbon dioxide gas concentration in the wastewater was 15.0 mg / L, and the pH of the wastewater was 4.9.

  From the above, the drainage discharged from the recovered water tank of the fuel cell system according to the present embodiment sufficiently satisfies the drainage standard (PH = 5.8 to 8.6) compared to the drainage of the conventional fuel cell system. I found it to satisfy.

  In each embodiment, the example in which the deaeration device is omitted has been described. However, the present invention is not limited to this. For example, as in the fuel cell system shown in FIG. 6, a degassing device may be provided in the recovery path for recovering the fuel exhaust gas condensed water, the fuel gas condensed water, and the fuel exhaust gas condensed water, and the same effect can be obtained.

  The fuel cell system according to the present invention can be drained with the recovered recovered PH remaining below the drainage standard, which is useful in technical fields such as stationary, mobile, and portable fuel cell systems. is there.

11, 21, 31, 41 Fuel cell system 12 Fuel cell 13 Air supply device 14 Fuel gas generation device 15 Combustion section 16 Fuel exhaust gas / fuel gas condenser 17 Combustion exhaust gas condenser 18, 38, 46 Recovery water tank 18a First tank 18b Second tank 19 Partition plate 22 First recovered water tank 23 Second recovered water tank 24 Connecting pipe 25, 42, 110 Drain port 32 Drain pipe 33 On-off valve 34 Control device 35 Water level sensor 36 Opening 37, 45 Inlet port 43 , 111 Fuel exhaust gas / fuel gas condensate water flow path 44, 112 Combustion exhaust gas condensate water flow path 113 Ion removal device 114 Water pump 115 Crevice 116 Bypass flow path

Claims (4)

A fuel gas generation device that generates a fuel gas mainly composed of hydrogen by processing a raw material gas, a fuel cell that generates power using hydrogen in the fuel gas and oxygen in the air, and stores recovered water A fuel cell system comprising at least a recovered water tank,
The recovered water tank has a first tank that is partitioned by a partition plate that forms a gap through which the recovered water passes between the bottom surface of the recovered water tank and a second tank that has a drain port for venting air. And
Water vapor contained in the fuel exhaust gas discharged from the fuel cell, water vapor contained in the combustion exhaust gas obtained by burning at least one of the raw material gas, the fuel gas and the fuel exhaust gas supplied to the fuel gas generator, The recovered water obtained by condensing the water is recovered in the first tank of the recovered water tank, then passed through the gap and passed through the second tank, and surplus in the recovered water tank. The fuel cell system, wherein the recovered water is drained from the drain port of the second tank. A fuel gas generation device that generates a fuel gas mainly composed of hydrogen by processing a raw material gas, a fuel cell that generates power using hydrogen in the fuel gas and oxygen in the air, and stores recovered water A fuel cell system comprising at least a recovered water tank,
The recovered water tank includes a drain pipe provided with an open / close valve disposed on a bottom surface of the recovered water tank, an inlet port for receiving the recovered water disposed on an upper surface, an opening for venting to the atmosphere, and the recovered water tank. A water level sensor for detecting the water level stored in the water, and a control unit for controlling the on-off valve of the drain pipe,
Water vapor contained in the fuel exhaust gas discharged from the fuel cell, water vapor contained in the combustion exhaust gas obtained by burning at least one of the raw material gas, the fuel gas and the fuel exhaust gas supplied to the fuel gas generator, Collecting the recovered water obtained by condensing the water from the inlet,
The fuel cell system characterized in that the recovered water that has become surplus in the recovered water tank is drained by receiving a signal from the water level sensor and controlling the on-off valve of the drain pipe by the control unit. A fuel gas generation device that generates a fuel gas mainly composed of hydrogen by processing a raw material gas, a fuel cell that generates power using hydrogen in the fuel gas and oxygen in the air, and stores recovered water A fuel cell system comprising at least a tank,
The recovered water tank has a water inlet arranged on the bottom surface of the recovered water tank, and a water outlet venting to the atmosphere,
Water vapor contained in the fuel exhaust gas discharged from the fuel cell, water vapor contained in the combustion exhaust gas obtained by burning at least one of the raw material gas, the fuel gas and the fuel exhaust gas supplied to the fuel gas generator, The recovered water obtained by condensing the water is recovered from the water inlet, and the recovered water remaining in the recovered water tank is discharged from the outlet. 2. The fuel cell system according to claim 1, wherein the first tank includes an opening that vents air to a position higher than the drain port of the second tank.

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