JP2009087609A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend the life of ion exchange resin by promoting decarboxylation of condensed water, in a fuel cell system. <P>SOLUTION: The fuel cell system comprises: at least one condensator among condensators 41-44 in which the steam in the combustion exhaust gas from a reformer 20 and anode gas as well as the anode-off gas and cathode-off gas from a fuel cell 10 is condensed for recovering; a condensed water tank 51 for holding the condensed water from the condensators 41-44; a deionizer 54 which incorporates an ion exchange resin for purifying the condensed water from the condensed water tank 51; and an air intaking device 52 which is provided in front of the deionizer 54 to derive condensed water to the deionizer 54 by performing air-intaking in which the condensed water from the condensed water tank 51 takes in air by flowing of condensed water. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell system.

As one type of fuel cell system, one shown in Patent Document 1 is known. As shown in FIGS. 1 and 2 of Patent Document 1, the fuel cell system includes a reformer 2, a fuel cell 1, a condenser 7 that condenses water in exhaust gas from the fuel cell 1, A water storage tank 8 for storing the water condensed by the condenser 7 is provided, and the water stored in the water storage tank 8 is used in the reformer 2. That is, the fuel cell system uses hydrogen produced water as a raw material to produce hydrogen by reforming it, and uses it as a fuel, as hydrogen produced water or fuel cell cooling water that requires high purity. The moisture in the gas and anode off gas is condensed and used. In this case, carbon dioxide in each gas dissolves in the condensed water and contains a relatively large amount of carbon dioxide, which becomes a load on the ion exchange resin 13b used for water purification and shortens the life. ing. On the other hand, in the fuel cell system disclosed in Patent Document 1, the water-retained retaining portion 20 that temporarily stores the water condensed by the condenser 7 in the water flow path from the condenser 7 to the water storage tank 8. It has.
Japanese Patent Laid-Open No. 2003-31255

  In the fuel cell system described in Patent Document 1 described above, the retention portion 20 can reduce carbonate ions contained in the condensed water condensed by the condenser, but the reduction (decarboxylation) is not. It was enough. That is, the lifetime of the ion exchange resin for purifying condensed water is not sufficient.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to further promote the decarboxylation of condensed water in the fuel cell system and to prolong the life of the ion exchange resin.

  In order to solve the above-mentioned problem, the structural feature of the invention according to claim 1 is that the combustion exhaust gas and anode gas from the reformer, and the water vapor in each of the anode off-gas and cathode off-gas from the fuel cell, respectively. At least one of the condensers that condenses and recovers the condensed water, a condensed water tank that stores condensed water from the condenser, and ion exchange that purifies the condensed water from the condensed water tank A deionizer with a built-in resin, and a deionizer provided in front of the deionizer, sucks the gas from the condensed water tank through the condensed water flow, and draws the condensed water to the deionizer. And an intake device.

  Further, the constitutional feature of the invention according to claim 2 is that the water vapor in the combustion exhaust gas and anode gas from the reformer and the anode off-gas and cathode off-gas from the fuel cell are condensed and the condensed water is condensed. At least one of the condensers to be recovered, a condensed water tank that stores condensed water from the condenser, and a deionizer that incorporates an ion exchange resin that purifies the condensed water from the condensed water tank Provided in front of the deionizer, and has a structure in which the pressure of the fluid is smaller at the outlet than at the inlet, and the condensed water from the condensate tank is decompressed by the structure and led to the deionizer. And a decompression device.

  Further, the constitutional feature of the invention according to claim 3 is that the water vapor in the combustion exhaust gas and anode gas from the reformer and the anode off-gas and cathode off-gas from the fuel cell are condensed and the condensed water is condensed. At least one of the condensers to be recovered, a condensed water tank that stores condensed water from the condenser, and a deionizer that incorporates an ion exchange resin that purifies the condensed water from the condensed water tank And a mist spraying device that is provided in front of the deionizer and sucks the condensed water from the condensed water tank by the supplied gas flow into a mist and leads it to the deionizer. .

  According to a fourth aspect of the present invention, in the first aspect, the intake device is supplied with the cathode offgas from the fuel cell, and the condensed water sucks the cathode offgas.

  According to a fifth aspect of the present invention, in the fuel cell system according to the first aspect, the intake device is supplied with air in the atmosphere and the condensed water sucks in the air.

  Further, the structural feature of the invention according to claim 6 is that in any one of claims 1, 4 and 5, the condensate from the intake device is stored between the intake device and the deionizer. And a gas-liquid separator for separating gas from the condensed water.

  According to a seventh aspect of the present invention, there is provided a structural feature of the invention according to the second aspect, wherein the condensed water from the pressure reducing device is stored between the pressure reducing device and the deionizer, and the gas is separated from the condensed water. A gas-liquid separator is further provided.

  Further, the structural feature of the invention according to claim 8 is that in claim 3, the condensate from the spray device is stored between the spray device and the deionizer, and the gas is separated from the condensed water. A gas-liquid separator is further provided.

  A structural feature of the invention according to claim 9 is that, in any one of claims 6 to 8, the gas-liquid separation device is open to the atmosphere.

  A structural feature of the invention according to claim 10 is that, in any one of claims 6 to 8, the gas-liquid separation device is directly connected to a deionizer.

  The structural feature of the invention according to claim 11 is that, in claim 10, the deionizer is disposed below the gas-liquid separator.

  The structural feature of the invention according to claim 12 is that, in any one of claims 1 to 11, the condensed water from the condensed water tank is continuously fed to the pure water device.

  A structural feature of the invention according to claim 13 is that, in any one of claims 1 to 11, the condensed water from the condensed water tank is intermittently sent to the deionizer.

  In the invention according to claim 1 configured as described above, the intake device is provided in front of the deionizer, and the intake water in which the condensed water from the condensed water tank sucks the gas by the flow of the condensed water is performed. The condensed water is led to a deionizer. In this case, decarbonation of the condensed water can be further promoted by making the gas contact the condensed water positively and efficiently using the flow of the condensed water. Therefore, since the condensed water with a further reduced carbon dioxide concentration is supplied to a pure water device incorporating the ion exchange resin, the life of the ion exchange resin can be extended.

In the invention according to claim 2 configured as described above, the decompression device is provided in front of the deionizer, and has a structure in which the pressure of the fluid is smaller at the outlet than at the inlet, and the condensed water tank The condensed water from the water is decompressed by the structure and led to a pure water device. In this case, decarboxylation of the condensed water can be further promoted by reducing the pressure of the condensed water to gasify the carbon dioxide dissolved in the condensed water. The decarboxylation here is a phenomenon in which carbon dioxide dissolved in water is removed. Specifically, carbon dioxide dissolved in water exists in the form of carbonic acid (H ₂ CO ₃ ), hydrogen carbonate ions (HCO ₃ ⁻ ), and carbonate ions (CO ₃ ²⁻ ). Decarboxylation is the reduction of these. Therefore, since the condensed water with a further reduced carbon dioxide concentration is supplied to a pure water device incorporating the ion exchange resin, the life of the ion exchange resin can be extended.

  In the invention which concerns on Claim 3 comprised as mentioned above, a spraying apparatus draws in the condensed water from a condensed water tank with the flow of the supplied gas, makes it mist-like, and guides it to a pure water device. In this case, decarbonation of the condensed water can be further promoted by bringing the condensed water atomized into contact with the gas (air) positively and efficiently. Therefore, since the condensed water with a further reduced carbon dioxide concentration is supplied to a pure water device incorporating the ion exchange resin, the life of the ion exchange resin can be extended.

  In the invention according to claim 4 configured as described above, in the invention according to claim 1, since the cathode offgas from the fuel cell is supplied to the intake device and the condensed water sucks in the cathode offgas, the fluid pressure Inhalation can be performed more efficiently by using a cathode off gas having

  In the invention according to claim 5 configured as described above, in the invention according to claim 1, the air intake apparatus is supplied with air in the atmosphere and the condensed water sucks in air. Cost reduction can be achieved without using a special gas.

  In the invention according to claim 6 configured as described above, in the invention according to any one of claims 1, 4 and 5, the gas-liquid separation device is provided between the intake device and the deionizer. Since the condensed water from the intake device is stored and the gas is separated from the condensed water, carbon dioxide dissolved in the condensed water can be further removed.

  In the invention according to claim 7 configured as described above, in the invention according to claim 2, the gas-liquid separation device is provided between the pressure reducing device and the deionizer to store condensed water from the pressure reducing device. Since gas is separated from the condensed water, carbon dioxide dissolved in the condensed water can be further removed.

  In the invention according to claim 8 configured as described above, in the invention according to claim 3, the gas-liquid separation device is provided between the spraying device and the deionizer to store condensed water from the spraying device. Since gas is separated from the condensed water, carbon dioxide dissolved in the condensed water can be further removed.

  In the invention according to claim 9 configured as described above, in the invention according to any one of claims 6 to 8, the gas-liquid separator is open to the atmosphere. As a result, the gas in the space of the gas-liquid separation device is easily ventilated with the atmosphere, so that the space can be kept low to almost the same carbon dioxide concentration as the atmosphere, thus promoting decarboxylation without reducing the decarboxylation capacity. be able to. In addition, the decarbonation is promoted by the action of the intake device, the decompression device, and the spray device, and it is not necessary to lengthen the air release time in order to contact the atmosphere and perform the decarboxylation, thereby shortening the air release time. Since it can do, it can suppress that a foreign material and various germs mix in a gas-liquid separation apparatus.

  In the invention according to Claim 10 configured as described above, in the invention according to any one of Claims 6 to 8, the gas-liquid separation device is directly connected to the deionizer. Compared with the case where the apparatus and the deionizer are arranged separately, the entire fuel cell system can be reduced in size.

  In the invention which concerns on Claim 11 comprised as mentioned above, in the invention which concerns on Claim 10, the pure water device is arrange | positioned under the gas-liquid separator. Thereby, since the condensed water of the gas-liquid separator flows into the deionizer by its own weight, it is not necessary to provide a supply device such as a pump, so that the fuel cell system can be reduced in size and cost.

  In the invention according to claim 12 configured as described above, in the invention according to any one of claims 1 to 11, the condensed water from the condensed water tank is continuously fed to the deionizer. Therefore, when there is almost no remaining amount of the pure water tank, it is possible to appropriately cope with a case where a large amount of reforming water is continuously supplied to the reformer.

  In the invention according to claim 13 configured as described above, in the invention according to any one of claims 1 to 11, the condensed water from the condensed water tank is intermittently sent to the deionizer. Therefore, water can be appropriately fed according to the remaining amount of the condensed water tank.

  Hereinafter, an embodiment of a fuel cell system according to the present invention will be described. FIG. 1 is a schematic diagram showing an outline of this fuel cell system. This fuel cell system includes a fuel cell 10 and a reformer 20 that generates fuel (anode gas, reformed gas) containing hydrogen gas necessary for the fuel cell 10.

  The fuel cell 10 includes a fuel electrode 11 and an air electrode 12 that is an oxidant electrode. The anode gas supplied to the fuel electrode 11 and the air (cathode gas) that is the oxidant gas supplied to the air electrode 12. To generate electricity.

  The reformer 20 steam-reforms the reforming raw material and supplies a hydrogen-rich reformed gas to the fuel cell 10, and includes a burner (combustion unit), a reforming unit, a carbon monoxide shift reaction unit (hereinafter referred to as a “burning unit”). , A CO shift part) and a carbon monoxide selective oxidation reaction part (hereinafter referred to as a CO selective oxidation part). Examples of the reforming raw material include natural gas, LPG, kerosene, gasoline, methanol, and the like. In this embodiment, natural gas will be described.

  The burner is supplied with the reformed gas from the outside without passing through the fuel cell 10 from the combustion fuel or the CO selective oxidizer during start-up operation, or the anode off gas (supplied to the fuel cell) from the fuel electrode 11 of the fuel cell 10 during steady operation. The reformed gas discharged without being used) is supplied, and each of the supplied combustible gases is combusted with combustion air and the combustion gas is led to the reforming section. This combustion gas heats the reforming section (so as to be in the activation temperature range of the catalyst of the reforming section), and then is discharged to the outside through the fourth condenser 44.

  The reforming unit is modified by a catalyst (for example, a Ru or Ni-based catalyst) in which the reforming unit is filled with a mixed gas obtained by mixing the supplied reforming raw material with reforming water (steam) from the pure water tank 55. To produce hydrogen gas and carbon monoxide gas (so-called steam reforming reaction). At the same time, carbon monoxide and steam generated by the steam reforming reaction are converted into hydrogen gas and carbon dioxide (so-called carbon monoxide shift reaction). These generated gases (so-called reformed gas) are led to the CO shift section.

  The CO shift unit converts carbon monoxide and water vapor contained in the reformed gas into a hydrogen gas and a carbon dioxide gas by reacting them with a catalyst (for example, a Cu or Zn-based catalyst) filled therein. Yes. As a result, the reformed gas is led to the CO selective oxidation unit with a reduced carbon monoxide concentration.

  The CO selective oxidation unit uses a catalyst (for example, a Ru-based or Pt-based catalyst) filled with carbon monoxide remaining in the reformed gas and CO purification air further supplied from the outside. Carbon dioxide is produced by the reaction. As a result, the reformed gas is further reduced in carbon monoxide concentration (10 ppm or less) and is led to the fuel electrode 11 of the fuel cell 10 through the anode gas supply pipe 33.

  A cathode gas supply pipe 31 that supplies cathode gas and a cathode offgas exhaust pipe 32 that discharges cathode offgas are connected to the air electrode 12 of the fuel cell 10. A CO selective oxidation unit of the reformer 20 is connected to the inlet of the fuel electrode 11 of the fuel cell 10 through an anode gas supply pipe 33 for supplying anode gas. A burner of the reformer 20 is connected to a lead-out port of the fuel electrode 11 through an anode off-gas supply pipe 34 connected to a combustion fuel supply pipe 35 described later, and the anode off-gas discharged from the fuel electrode 11. Can be supplied to the burner.

  A combustion fuel supply pipe 35 that supplies combustion fuel and combustion air to the burner is connected to the reformer 20, and a combustion exhaust gas exhaust pipe 36 that discharges combustion gas generated by the burner is connected to the reformer 20. Further, the reformer 20 is connected to a reforming material supply pipe 37 for supplying a reforming material and reforming water to the reforming section.

  In the middle of the cathode offgas exhaust pipe 32, the anode gas supply pipe 33, the anode offgas supply pipe 34, and the combustion exhaust gas exhaust pipe 36, first to fourth condensers 41 to 44 are disposed.

  The first condenser 41 condenses water vapor in the cathode offgas discharged from the air electrode 12 of the fuel cell 10 flowing through the cathode offgas exhaust pipe 32 and collects the condensed water. The second condenser 42 condenses the water vapor in the anode gas supplied to the fuel electrode 11 of the fuel cell 10 flowing through the anode gas supply pipe 33 and recovers the condensed water. The third condenser 43 condenses the water vapor in the anode off-gas discharged from the fuel electrode 11 of the fuel cell 10 flowing in the anode off-gas supply pipe 34 and recovers the condensed water. The fourth condenser 44 condenses water vapor in the combustion exhaust gas flowing through the combustion exhaust gas exhaust pipe 36 and recovers the condensed water. The condensers 41 to 44 are supplied with a low-temperature liquid in a hot water storage tank (not shown) or a liquid cooled by a radiator and a cooling fan, and circulates between the liquids and the condensers 41 to 44. Water vapor in each gas is condensed by heat exchange with each gas.

  Since carbon dioxide is not generated at the air electrode 12 of the fuel cell, the carbon dioxide in the cathode off-gas is almost the same as the concentration in the cathode gas, that is, the concentration in the atmosphere. Therefore, the amount of carbon dioxide in the condensed water of the first condenser 41 is very small. However, in the other condensers, that is, the second condenser 42 to the fourth condenser, a relatively large amount of carbon dioxide is contained in the anode gas, the anode off gas, and the combustion exhaust gas due to the reaction in the reformer 20. The amount of carbon dioxide in the condensed water is relatively large.

  Each of the condensers 41 to 44 communicates with the condensed water tank 51 via the pipe 38, and the condensed water condensed in the fourth condenser 44 is led out to the condensed water tank 51 and collected. ing. The condensed water tank 51 temporarily stores condensed water. The condensed water tank 51 is provided with a water amount sensor (water level sensor) (not shown) that detects the amount of condensed water in the condensed water tank 51. The water amount sensor is, for example, a float type or capacitance type water level gauge. The water amount sensor transmits a detection signal to the control device.

The fuel cell system further includes an intake device 52, a gas-liquid separator 53, a deionizer 54, and a deionized water tank 55.
The intake device 52 is disposed on a pipe 39 that connects the condensed water tank 51 and the deionizer 54. The intake device 52 is preferably arranged with the outlet portion of the intake device 52 facing the gas-liquid separator 53. The air intake device 52 is formed in a cylindrical shape and has a shape in which a central portion in the flow direction (longitudinal direction) is narrowed, and is penetrated in the central portion of the main body 52a to communicate the inside of the main body 52a with the atmosphere. And a suction pipe 52b. The tip of the suction pipe 52b is preferably arranged so as to be inclined toward the downstream side with respect to the flow in the main body 52a.

  In the intake device 52, when the condensed water flowing in from the inlet portion of the main body 52a flows toward the outlet portion, the pressure decreases along the inner wall surface of the main body 52a along with the flow of the condensed water. Inhalation is performed by sucking air from the atmosphere via 52. That is, the intake device 52 performs intake air in which the condensed water from the condensed water tank 51 sucks gas (air in the atmosphere) by the flow of the condensed water, and guides the condensed water to the pure water device 54.

  A condensed water pump 39 a is disposed in the middle of the pipe 39. The condensed water pump 39a is controlled by a control device, and pumps the condensed water pumped from the lower part of the condensed water tank 51 to the gas-liquid separator 53 (and hence the deionizer 54).

  The gas-liquid separator 53 is directly connected to the pure water device 54. The gas-liquid separator 53 is provided between the intake device 52 and the deionizer 54, stores the condensed water from the intake device 52, and separates the gas (carbon dioxide in the present embodiment) from the condensed water. Is. That is, the condensed water stored in the gas-liquid separation device 53 is allowed to stand, and the carbon dioxide dissolved in the condensed water naturally escapes due to the saturation balance between the gas and liquid. The gas-liquid separator 53 has an opening 53a, communicates with the atmosphere through the opening 53a, and is open to the atmosphere.

  The deionizer 54 incorporates an ion exchange resin and is filled with, for example, a granular ion exchange resin. The deionizer 54 purifies condensed water from the condensed water tank 51 (or / and makeup water from a water supply source) with ion exchange resin. The deionizer 54 communicates with the deionized water tank 55 through the pipe 61, and the deionized water in the deionizer 54 is led out to the deionized water tank 55 through the pipe 61. The pipe 61 is provided with a pure water pump 61a. The pure water pump 61 a is controlled by a control device, and pumps pure water in the pure water device 54 to the pure water tank 55.

  A partition wall member 56 is interposed between the gas-liquid separator 53 and the deionizer 54. The partition member 56 partitions the gas-liquid separator 53 and the pure water device 54. The gas-liquid separator 53 and the deionizer 54 are communicated with each other through a partition member 56. The partition member 56 is, for example, a stainless steel mesh or a ceramic ball, and has a structure that allows condensed water to pass but does not allow ion exchange resin to pass. Thereby, it can suppress that an ion exchange resin moves to a gas-liquid separator, and can suppress adsorb | sucking a carbon dioxide gas directly.

  The pure water tank 55 stores the pure water derived from the pure water device 54. The pure water tank 55 is provided with a water amount sensor (water level sensor) (not shown) that detects the amount of pure water in the pure water tank 55. The water amount sensor is, for example, a float type or capacitance type water level gauge. The water amount sensor transmits a detection signal to the control device.

  The pure water tank 55 is connected to the reforming raw material supply pipe 37 via the reforming water supply pipe 62. The reforming water supply pipe 62 is provided with a reforming water pump (pure water pump) 62a which is a sending means. The reforming water pump 62 a is controlled by a control device, and pumps the reforming water (pure water) in the pure water tank 55 to the reforming section of the reformer 20. An evaporator is preferably provided in the middle of the reforming water supply pipe 62. The evaporator is heated, for example, by heat from the combustion exhaust gas discharged from the burner, the reforming unit, the CO shift unit, and the like, thereby steaming the reformed water fed under pressure.

  Next, the flow of the condensed water of the fuel cell system described above will be described. The condensed water collected by the first to fourth condensers 41 to 44 is temporarily stored in the condensed water tank 51 via the pipe 38. The condensed water in the condensed water tank 51 is sent to the gas-liquid separator 53 through the intake device 52 by the operation of the condensed water pump 39a. Condensed water tank 51 When condensed water passes through the intake device 52, air is sucked from the suction pipe 52b, so that air is blown into the condensed water. Thereby, decarbonation of condensed water can be promoted by bringing gas (air) into contact with condensed water in which carbon dioxide is dissolved positively and efficiently.

  Thus, the condensed water whose carbon dioxide concentration has been reduced is temporarily stored in the gas-liquid separator 53. Even during this time, carbon dioxide escapes from the condensed water as a gas due to the saturation balance between the gas and liquid, and therefore decarboxylation can be further promoted.

  Then, the condensed water whose carbon dioxide concentration is reduced by promoting the decarbonation in this way is purified by the ion exchange resin of the pure water device 54 and led to the pure water tank 55. The condensed water in the pure water tank 55 is sent to the reforming section of the reformer 20 by the operation of the pure water pump 62a as necessary.

  In addition, when there is almost no remaining amount of pure water tank or when a large amount of reformed water is continuously supplied to the reformer, the condensed water from the condensed water tank 51 is continuously supplied to the pure water device 54. Water may be sent. According to this, when there is almost no remaining amount of the pure water tank, the reforming water can be appropriately supplied to the reformer 20 when a large amount of reforming water is continuously supplied to the reformer. .

  Further, the condensed water from the condensed water tank may be intermittently sent to the deionizer. In this case, water can be appropriately fed according to the remaining amount of the condensed water tank detected by the water level sensor.

  As can be understood from the above description, according to the present embodiment, the intake device 52 is provided in front of the deionizer 54, and the condensed water from the condensed water tank 51 is gas ( Intake air that sucks in air in the atmosphere (air in the fuel cell system communicating with the atmosphere) is taken in, and the condensed water is led out to the deionizer 54 through the gas-liquid separator 52. In this case, decarbonation of the condensed water can be further promoted by making the gas contact the condensed water positively and efficiently using the flow of the condensed water. Accordingly, the condensed water with a further reduced carbon dioxide concentration is supplied to the deionizer 54 incorporating the ion exchange resin, so that the life of the ion exchange resin can be extended.

  Further, since the gas-liquid separator 53 is provided between the intake device 52 and the deionizer 54 and stores the condensed water from the intake device 52 and separates the gas from the condensed water, it dissolves in the condensed water. Carbon dioxide can be removed further.

  Further, the gas-liquid separator 53 is open to the atmosphere. As a result, since the gas in the space of the gas-liquid separator 53 is easily ventilated with the atmosphere, the space can be suppressed to a low carbon dioxide concentration that is almost the same as the atmosphere. can do.

  Further, since the gas-liquid separation device 53 is directly connected to the pure water device 54, the entire fuel cell system can be reduced in size as compared with the case where the gas-liquid separation device 53 and the pure water device 54 are arranged separately. Can do.

  The pure water device 54 is disposed below the gas-liquid separator 53. Thereby, since the condensed water of the gas-liquid separator 53 flows into the pure water device 54 by its own weight, it is not necessary to provide a supply device such as a pump, so that the fuel cell system can be reduced in size and cost. . It is more desirable that the deionizer 54 is disposed immediately below the gas-liquid separator 53.

  In addition, since the air in the atmosphere is supplied to the intake device 52 and the condensed water sucks in the air, the use of the atmosphere makes it possible to reduce the cost without using any special gas.

  In the above-described embodiment, the intake device 52 only needs to be provided in front of the deionizer 54, and is provided at any location between the condensed water pump 39a and the gas-liquid separator 53. You may do it.

  In the embodiment described above, the gas-liquid separation device 53 may be omitted.

  Moreover, in embodiment mentioned above, at least any one condenser should just be provided among the 1st-4th condensers 41-44.

  Moreover, when the some condenser is provided among the 1st-4th condensers 41-44, the intake device, the pressure reduction device, or the spraying device should just be provided in the at least 1 condenser.

  The present invention can also be applied to a fuel cell system in which the reformer 20 is not provided. In this case, at least one condenser is provided among the second condenser (condenser for anode gas) 42, the third condenser (condenser for anode offgas) 43, and the first condenser (condenser for cathode offgas) 41. It only has to be done. In this case, the anode gas is humidified by a humidifier such as a sprayer, and the humidification amount of the anode gas is adjusted by a condenser. The anode off gas contains moisture due to humidification of the anode gas and diffusion of generated water generated at the cathode, and the moisture is recovered by the condenser and reused.

  Next, a case where an intake device 57 is provided instead of the intake device 52 will be described with reference to FIG. Since it is the same structure except an intake device, the same code | symbol is attached | subjected and the description is abbreviate | omitted. The intake device 57 is provided in the middle of the pipe 39. It may be either upstream or downstream of the condensed water pump 39a. The intake device 57 includes a suction pipe 57a and a check valve 57b at the inlet of the suction pipe 57a. The suction pipe 57a communicates with the outside (for example, the atmosphere) and the inside of the pipe 38. The check valve 57b allows the flow of air from the outside into the pipe 38 and does not allow the flow of condensed water from the inside of the pipe 38 to the outside. The intake device 57 basically operates in the same manner as the intake device 52 so that gas from the outside is sucked by the flow of condensed water in the pipe 38. Also by this, the same operation and effect as the above-described intake device 52 can be obtained.

  Furthermore, a case where a pressure reducing device 58 is provided instead of the intake device 52 will be described with reference to FIG. Since it is the same structure except a pressure reduction apparatus, the same code | symbol is attached | subjected and the description is abbreviate | omitted. The decompressor 58 is provided in the middle of the pipe 39. It may be either upstream or downstream of the condensed water pump 39a. The decompression device 58 includes a main body 58a formed in a cylindrical shape and a constricted portion 58b provided in the center of the flow direction (longitudinal direction) of the main body 58a.

  In the decompression device 58, when the condensed water flowing in from the inlet portion of the main body 58a flows toward the outlet portion, the pressure is reduced by being throttled by the throttle portion 58b, so that the carbon dioxide dissolved in the condensed water is reduced. Bubbles appear as gas. Thus, the decompression device 58 is provided in front of the deionizer 54, and has a structure in which the pressure of the fluid is smaller at the outlet than at the inlet, and the condensed water from the condensed water tank 51 is removed by the structure. The pressure is reduced and the gas is discharged to the pure water device via the gas-liquid separator 53.

  In this case, decarboxylation of the condensed water can be further promoted by reducing the pressure of the condensed water to gasify the carbon dioxide dissolved in the condensed water. Accordingly, the condensed water with a further reduced carbon dioxide concentration is supplied to the deionizer 54 incorporating the ion exchange resin, so that the life of the ion exchange resin can be extended.

  In this case, the gas-liquid separator 53 is provided between the decompressor 58 and the deionizer 54, stores the condensed water from the decompressor 58, and separates the gas from the condensed water. The carbon dioxide dissolved in can be further removed.

  Furthermore, in the embodiment and the modified example to which the above-described intake device 52 is applied, the suction pipes 52b and 57a of the intake devices 52 and 57 communicate with the atmosphere. However, as shown in FIG. You may make it connect with few cathode off gas exhaust pipes 32. FIG. Specifically, the suction pipe 52 b is connected to the cathode offgas exhaust pipe 32 via the connection pipe 63. In addition, about the structure similar to FIG. 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  According to this, since the cathode offgas from the fuel cell 10 is supplied to the intake device 52b (or the intake device 57) and the condensed water sucks in the cathode offgas, the intake device 52b (or the intake device 57) uses the cathode offgas having a fluid pressure. Can be performed more efficiently.

  Furthermore, a modified example in which the suction pipes 52b and 57a of the intake devices 52 and 57 communicate with the cathode offgas exhaust pipe 32 via the connection pipe 63 will be described with reference to FIG. In this case, since the condensed water from the first condenser 41 has a low carbon dioxide concentration as described above, it does not need to be decarboxylated and is directly supplied to the pure water device 54. And the condensed water from the 2nd-4th condensers 42-44 is temporarily stored in the condensed water tank 51 similarly to embodiment mentioned above. Further, the deionizer 54 and the gas-liquid separator 53 are arranged separately. Further, the cathode offgas exhaust pipe 32 downstream from the first condenser 41 is communicated with the gas-liquid separator 53. According to this, the decarbonated treatment can be efficiently performed by appropriately separating the condensed water that does not require decarboxylation and the condensed water that requires decarboxylation. In addition, about the structure similar to FIG. 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  Next, a case where a mist blowing device 59 is provided instead of the intake device 52 will be described with reference to FIG. Since it is the same structure except a spraying apparatus, the same code | symbol is attached | subjected and the description is abbreviate | omitted. The spray device 59 is provided in the middle of the pipe 39. The condensed water pump 39a is omitted. The spraying device 59 is formed in a cylindrical shape, and has a main body 59a having a shape in which a central portion in the flow direction (longitudinal direction) is narrowed, and penetrates the central portion of the main body 59a, and communicates the inside of the main body 59a and the pipe 39. It is composed of a suction pipe 59b and an air pump 59c connected to the inlet of the main body 59a to send out air. Note that the tip of the suction pipe 59b is preferably arranged to be inclined toward the downstream side with respect to the flow in the main body 59a. Moreover, it is preferable that the spray device 59 is disposed with the outlet portion of the spray device 59 facing the gas-liquid separator 53.

  In this spraying device 59, when the air flowing in from the inlet portion of the main body 59a flows toward the outlet portion, the air flow is bent at the connecting portion of the main body 59a and the suction pipe 59b, so the pressure decreases. Condensed water is sucked from the condensed water tank 51 via the suction pipe 59 and is discharged in the form of a mist. That is, the spray device 59 sucks the condensed water from the condensed water tank 51 by the gas flow supplied, makes it into a mist, and guides it to the deionizer 54 through the gas-liquid separator 53.

  Thereby, decarboxylation of condensed water can be further promoted by bringing the condensed water mist into contact with gas (air) positively and efficiently. Accordingly, the condensed water with a further reduced carbon dioxide concentration is supplied to the deionizer 54 incorporating the ion exchange resin, so that the life of the ion exchange resin can be extended.

  In this case, the gas-liquid separation device 53 is provided between the spray device 59 and the deionizer 54, stores the condensed water from the spray device 59, and separates the gas from the condensed water. The carbon dioxide dissolved in can be further removed.

  In the above-described embodiments and modifications, the intake devices 52 and 57, the decompression device 58, and the spray device 59 are provided immediately before the deionizer 54 (if the gas-liquid separator 53 is also provided, the gas-liquid separator 53). It is preferable that it is disposed immediately before. Since the decarboxylated condensed water is supplied to the deionizer without taking time, the condensed water having a reduced carbonate concentration can be reliably supplied to the deionizer.

It is a schematic diagram showing an outline of one embodiment of a fuel cell system according to the present invention. It is a figure which shows the modification of the intake device shown in FIG. It is a figure which shows the modification which replaced with the intake device shown in FIG. 1, and applied the decompression device. It is a figure which shows the modification of the intake device shown in FIG. It is a figure which shows the modification of the intake device shown in FIG. It is a figure which shows the modification which replaced with the air intake apparatus shown in FIG. 1, and applied the spraying apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 11 ... Fuel electrode, 12 ... Air electrode, 20 ... Reformer, 41-44 ... 1st-4th condenser, 51 ... Condensed water tank, 52, 57 ... Intake device, 53 ... Gas-liquid Separation device, 54 ... pure water device, 55 ... pure water tank, 58 ... decompression device, 59 ... spraying device.

Claims (13)

At least one of the condensers for condensing water vapor in the combustion exhaust gas and anode gas from the reformer, and the anode off-gas and cathode off-gas from the fuel cell, respectively, and collecting the condensed water;
A condensed water tank for storing the condensed water from the condenser;
A deionizer containing an ion exchange resin that purifies the condensed water from the condensed water tank;
An intake device that is provided in front of the deionizer and sucks gas into the deionizer by the condensed water from the condensate tank and sucks gas by the flow of the condensed water; and A fuel cell system comprising: At least one of the condensers for condensing water vapor in the combustion exhaust gas and anode gas from the reformer, and the anode off-gas and cathode off-gas from the fuel cell, respectively, and collecting the condensed water;
A condensed water tank for storing the condensed water from the condenser;
A deionizer containing an ion exchange resin that purifies the condensed water from the condensed water tank;
It is provided in front of the deionizer and has a structure in which the pressure of the fluid is smaller at the outlet than at the inlet, and the condensed water from the condensed water tank is depressurized by the structure to the deionizer. A fuel cell system comprising: a decompression device for deriving. At least one of the condensers for condensing water vapor in the combustion exhaust gas and anode gas from the reformer, and the anode off-gas and cathode off-gas from the fuel cell, respectively, and collecting the condensed water;
A condensed water tank for storing the condensed water from the condenser;
A deionizer containing an ion exchange resin that purifies the condensed water from the condensed water tank;
A spraying device provided in front of the water purifier and sucking the condensed water from the condensed water tank by the flow of gas supplied to form a mist and leading it to the water purifier. A fuel cell system.   2. The fuel cell system according to claim 1, wherein the intake device is supplied with cathode offgas from the fuel cell, and the condensed water sucks the cathode offgas.   2. The fuel cell system according to claim 1, wherein air in the atmosphere is supplied to the intake device, and the condensed water sucks the air.   6. The air according to claim 1, wherein the air is provided between the intake device and the deionizer to store the condensed water from the intake device and separate a gas from the condensed water. A fuel cell system further comprising a liquid separator.   The gas-liquid separation device according to claim 2, further comprising a gas-liquid separation device that is provided between the decompression device and the deionizer and stores the condensed water from the decompression device and separates the gas from the condensed water. A fuel cell system.   The gas-liquid separation device according to claim 3, further comprising a gas-liquid separation device that is provided between the spray device and the deionizer, stores the condensed water from the spray device, and separates the gas from the condensed water. A fuel cell system.   9. The fuel cell system according to any one of claims 6 to 8, wherein the gas-liquid separator is open to the atmosphere.   9. The fuel cell system according to claim 6, wherein the gas-liquid separator is directly connected to the deionizer.   11. The fuel cell system according to claim 10, wherein the deionizer is disposed below the gas-liquid separator.   The fuel cell system according to any one of claims 1 to 11, wherein the condensed water from the condensed water tank is continuously fed to the deionizer. The fuel cell system according to any one of claims 1 to 11, wherein the condensed water from the condensed water tank is intermittently sent to the deionizer.

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