JP2005276621A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system in which a long term operation can be realized by suppressing proliferation of microorganisms in recovered water without increasing the number of parts items, without enlarging the whole system, and without ensuing cost rise in the fuel cell system. <P>SOLUTION: The fuel cell system includes a pure water device 40 which converts the recovered water into pure water from a condenser to condense and recover steam in an exhausted gas sent out from a fuel electrode and an air electrode of the fuel cell, and a water reservoir 50 which stores the purified recovered water from the pure water device 40. The pure water device 40 includes a passage 42 formed in an open-upward U-shape, and a filling part 43 composed of an ion exchange resin 43a is formed in that passage 42. A filter 44 is installed in contact with the upper face of the filling part 43. The filling part 43 and the filter 44 are always placed in a liquid. Tap water is supplied to the filter 44 at every prescribed time by a tap water supply means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell system for generating power by supplying reformed gas and air generated by a reformer to a combustion cell, and more particularly to a recovered water system of the fuel cell system.

  As a fuel cell system, the fuel cell 1 that generates electricity using hydrogen supplied to the fuel electrode and oxygen supplied to the air electrode, and water vapor in the exhaust gas (air off-gas) delivered from the air electrode are at least condensed. A condenser (product water recovery tower 21) that collects the recovered water, a water reservoir (recovered water tank 23) that stores the recovered water supplied from the condenser, and a pure water that recovers the recovered water supplied from the water reservoir. Water purifier (water treatment device 41), and a reformer (modified) that reforms purified water and fuel (raw fuel) supplied from the water purifier to derive reformed gas. And a quality device 2) are known (Patent Document 1). In this system, in order to suppress the growth of microorganisms in the recovered water stored in the recovered water tank 23, a method is disclosed in which the recovered water is temporarily heated to 70 ° C. or higher and sterilized. Specifically, the recovered water circulation system 30 is provided with a heat exchanger 26 for heating the recovered water and a flow rate control means 31 for opening and closing the circulation system 30.

  Further, as a fuel cell system similar to Patent Document 1, the water vapor in the exhaust gas 7 and 8 of the fuel cell and the fuel reformer 2 is condensed and recovered, and stored as a mixed water 26 to which tap water is added. What has a water recovery system 20, a mixed water circulation system 25 that circulates the mixed water of the product water recovery system 20, and a water treatment system 30 that converts the mixed water into pure water and supplies it to the cooling water circulation system 10 is known. (Patent Document 2). In this system, an antibacterial filter 41 is provided in the mixed water circulation system 25, and an antibacterial filter 42 is also provided on the upstream side of the pure water device 31 of the water treatment system 30. Therefore, the amount of microorganisms in the mixed water that has passed through the antibacterial filter 41 is gradually reduced, and the mixed water 26 in which the amount of microorganisms is reduced is stably supplied to the water treatment system 30. In addition, the mixed water supplied to the water treatment system 30 is filtered again by the antibacterial filter 42 and adsorbs and filters other impurities contained in the mixed water. The supplied mixed water is in a state in which the amount of microorganisms and the amount of impurities are greatly reduced, and highly purified pure water is supplied to the cooling water circulation system 10.

  Further, instead of the antibacterial filter 42 provided on the upstream side of the pure water device 31 of the water treatment system 30 described in Patent Document 2, an ultraviolet sterilizer (indicated by reference numeral 41 in Patent Document 3). There is also known one provided with (Patent Document 3). Also in this system, the microorganisms in the mixed water 26 are sterilized by irradiation with ultraviolet rays, so that the microorganisms remaining in the mixed water 26 are sterilized by ultraviolet rays, and the mixed water that is almost aseptic is supplied to the ion-exchange pure water device 31. Supplied. In each of the above-mentioned patent documents, in any case, when the recovered water in the generated water recovery tower 21 is less than a predetermined amount, it is replenished by supplying tap water.

  In addition, as a fuel cell system, the fuel cell 11 that generates power using hydrogen supplied to the fuel electrode and oxygen supplied to the air electrode, and water vapor in the exhaust gas respectively sent from the fuel electrode and air electrode are condensed. The condensers (collectors 14 and 17) that collect the recovered water as described above, the water reservoir (water tank 18) that stores the recovered water supplied from these condensers, and the recovered water supplied from the water reservoir are purified. Also known are water purifiers (ion exchange resin towers 116 and 115), and sprays of purified water supplied from these water purifiers to the humidifiers 13 and 16 (Patent Documents). 4). In this system, activated carbon cylinders 121 and 119 filled with activated carbon are provided between the water tank 18 and the ion exchange resin towers 116 and 115, respectively. The activated carbon cylinders 121 and 119 cause deterioration of the ion exchange resin. It efficiently captures chlorine-based oxides that induce water.

Further, the cooling water which takes away the heat generated in the fuel cell 1 and is released in the radiator 15 is circulated by the pump 16 and sent to the detector 17. The detector 17 determines whether or not microorganisms are present in the cooling water. It is also known that the sterilization apparatus 18 is instructed to kill microorganisms when the result is detected, and the sterilization apparatus 18 irradiates ultraviolet rays in accordance with this instruction to kill the microorganisms ( Patent Document 5).
JP 08-138714 A (5th page, FIG. 1) JP 09-063611 (page 3-4, FIG. 1) JP 09-063612 A (page 4, FIG. 1) Japanese Patent Laying-Open No. 2003-151591 (page 3-5, FIG. 1) JP 2002-270211 A (page 3-4, FIG. 1)

  In the fuel cell system described in Patent Document 1 described above, a recovered water circulation system 30 is provided and recovered in the recovered water circulation system 30 in order to suppress the growth of microorganisms in the recovered water stored in the recovered water tank 23. Propagation of microorganisms can be suppressed by providing the heat exchanger 26 for heating water and the flow rate control means 31 for opening and closing the circulation system 30, but the number of parts constituting the system increases, and the system There was a problem that the whole was increased in size and increased in cost.

  Also in the fuel cell system described in Patent Document 2 described above, a mixed water circulation system 25 that circulates the mixed water of the generated water recovery system 20 is provided, an antibacterial filter 41 is provided in the mixed water circulation system 25, and water Providing the antibacterial filter 42 on the upstream side of the pure water device 31 of the treatment system 30 can suppress the growth of microorganisms, but has the same problem as described above.

  Also in the fuel cell system described in Patent Document 3 described above, a mixed water circulation system 25 that circulates the mixed water of the generated water recovery system 20 is provided, an antibacterial filter 41 is provided in the mixed water circulation system 25, and water Providing an ultraviolet sterilizer on the upstream side of the pure water device 31 of the treatment system 30 can suppress the growth of microorganisms, but has the same problem as described above.

  The present invention has been made to solve the above-described problems, and suppresses the growth of microorganisms in recovered water without increasing the number of parts, without increasing the size of the entire system, and without increasing the cost. Accordingly, an object of the present invention is to provide a fuel cell system that can realize long-term operation.

  In order to solve the above-mentioned problem, the constitutional feature of the invention according to claim 1 is a condenser for condensing at least water vapor in exhaust gas sent from a fuel electrode or an air electrode of a fuel cell and recovering it as recovered water. And an introduction part provided with an introduction port for introducing the recovered water supplied from the condenser, and a filling part filled with an ion exchange resin for purifying the recovered water inside with one end connected to the introduction part A fuel having a recovered water system having at least a pure water device comprising a passage and a lead-out portion connected to the other end of the passage and provided with a lead-out port through which the recovered water purified through the passage is led. The battery system further includes tap water supply means for periodically supplying tap water to the recovered water system.

  Further, the structural feature of the invention according to claim 2 is that in claim 1, the tap water supply means includes a tap water supply pipe having one end connected to the recovered water system and the other end connected to a tap water supply source. A supply means interposed in a tap water supply pipe to supply tap water in an adjustable manner, and a control means for controlling the supply of tap water by the supply means. The control means has a predetermined amount every predetermined time. The supply means is controlled to supply tap water.

  According to a third aspect of the present invention, in the second aspect of the present invention, the recovered water system further includes a filter disposed between the condenser and the filling portion for filtering the recovered water, and the tap water supply means includes At least supply tap water to the filter.

  According to a fourth aspect of the present invention, in the third aspect, the pure water device is configured such that the filling portion is always immersed in the liquid in the pure water device, and the filter is disposed in the liquid. The tap water supply means supplies tap water to the liquid.

  The structural feature of the invention according to claim 5 is that in any one of claims 1 to 4, the filling portion is further filled with an antibacterial agent.

  A structural feature of the invention according to claim 6 is that in any one of claims 1 to 4, the filling portion is further filled with activated carbon.

  While the fuel cell system according to the invention according to claim 1 configured as described above is in operation, there is a possibility that microorganisms may propagate on a portion of the recovered water system where clogging occurs and the liquid flow becomes slow, Since tap water is regularly supplied by the tap water supply means, microorganisms propagated by residual chlorine in the tap water can be periodically sterilized. According to this, it is possible to suppress the growth of microorganisms in the recovered water with little change to the conventional system, that is, without increasing the number of parts, without increasing the size of the entire system, and without increasing the cost. Thus, a fuel cell system that can realize long-term operation can be provided.

  In the invention according to claim 2 configured as described above, the control means controls the supply means so as to supply a predetermined amount of tap water every predetermined time, so that the filter can be sterilized efficiently, Tap water used for sterilization can be saved.

  In the invention according to claim 3 configured as described above, the recovered water is filtered by the filter disposed between the condenser and the filling unit, while the foreign matter collected in the filter causes clogging. Microorganisms may grow on the filter due to the slow flow of liquid, but tap water is supplied to the filter by tap water supply means, so sterilize the propagated microorganisms by residual chlorine in tap water. Can do.

  In the invention according to claim 4 configured as described above, the deionizer is configured such that the filling portion is always immersed in the liquid in the deionizer, the filter is disposed in the liquid, and tap water supply The means supplies tap water to the liquid. As a result, the supplied tap water diffuses into the liquid in the deionizer and is evenly supplied evenly to the filters arranged in the liquid. Therefore, the effect of the sterilization effect of the filter by tap water can be further improved.

  In the invention according to claim 5 configured as described above, since the filling portion is further filled with the antibacterial agent, the filling portion is more reliably antibacterial by the antibacterial action of the antibacterial agent in addition to the sterilizing action of tap water. be able to.

  In the invention according to claim 6 configured as described above, since the filling portion is further filled with activated carbon, it is prevented that residual chlorine content of tap water is removed by activated carbon and supplied downstream of the deionizer. can do. Moreover, deterioration of the ion exchange resin due to residual chlorine can be suppressed. Moreover, since installation of another apparatus for removing the chlorine content of tap water can be omitted, it is possible to prevent an increase in the number of parts, an increase in the size of the entire system, and an increase in cost.

  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. The fuel cell system includes a fuel cell 10 and a reformer 20 that generates a reformed gas containing hydrogen gas necessary for the fuel cell 10.

  The fuel cell 10 includes a fuel electrode 11, an air electrode 12, and an electrolyte 13 interposed between both electrodes 11, 12. The reformed gas supplied to the fuel electrode 11 and the air supplied to the air electrode 12 ( Electricity is generated using cathode air). In the present embodiment, the case where the fuel cell 10 is a polymer electrolyte fuel cell will be described. Therefore, the electrolyte 13 is an ion exchange membrane (particularly a cation exchange membrane), and the fuel is natural gas or methanol.

  In the fuel electrode 11, the supplied hydrogen gas reacts as shown in the following chemical formula 1, and the product hydrogen ions are supplied to the air electrode 12 through the electrolyte 13 and the anode containing unreacted hydrogen gas. Off-gas is discharged. In the air electrode 12, oxygen in the supplied air and hydrogen ions supplied from the fuel electrode 11 through the electrolyte 13 react as shown in the following chemical formula 2 to generate water (water vapor) and include the water vapor. The cathode off gas is discharged.

(Chemical formula 1)
H ₂ → 2H ⁺ + 2e ⁻
(Chemical formula 2)
2H ⁺ + 1 / 2O ₂ + 2e ⁻ → H ₂ O
Here, the electrons generated in the fuel electrode 11 reach the air electrode 12 through a circuit (inverter circuit) connected to the outside, and the reaction shown in the chemical formula 2 is performed using the electrons in the air electrode 12. As a result, the fuel cell 10 generates power.

  A supply pipe 61 that supplies air and a discharge pipe 62 that discharges cathode off-gas are connected to the air electrode 12 of the fuel cell 10. Air is humidified in the middle of the supply pipe 61 and the discharge pipe 62. A humidifier 14 is provided. The humidifier 14 is of a water vapor exchange type and dehumidifies water vapor in the gas discharged from the discharge pipe 62, that is, from the air electrode 12, and supplies the water vapor into the supply pipe 61, that is, air supplied to the air electrode 12. And humidify.

  The reformer 20 steam-reforms fuels such as natural gas, LP gas, kerosene, and methanol, and supplies hydrogen-rich reformed gas to the fuel cell 10. It is composed of a carbon oxide shift reaction part (hereinafter referred to as a CO shift part) 23 and a carbon monoxide selective oxidation reaction part (hereinafter referred to as a CO selective oxidation part) 24.

  The burner 21 is supplied with combustion fuel and combustion air from the outside during start-up, or anode off-gas (reformed gas discharged to the fuel cell and not used) from the fuel electrode 11 of the fuel cell 10 during steady operation. Is supplied, the supplied gas is combusted, and the combustion gas is led out to the reforming section 22. This combustion gas heats the reforming section 22 (so that it becomes the activation temperature range of the catalyst of the reforming section 22), and then the water vapor contained in the combustion gas is condensed through the combustion gas condenser 34. And exhausted to the outside. The combustion gas condenser 34 communicates with a deionizer 40 described later via a pipe 63. The combustion gas condenser 34 is disposed above the deionizer 40, and the pipe 63 has a structure in which the liquid flowing inside falls without falling to the deionizer 40 due to its own weight.

  The reforming unit 22 reforms a mixed gas obtained by mixing fuel supplied from the outside with water vapor from an evaporation unit (not shown) by a catalyst charged in the reforming unit 22 to generate 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 unit 23.

  The CO shift unit 23 is converted into hydrogen gas and carbon dioxide gas by reacting carbon monoxide and water vapor contained in the reformed gas with a catalyst filled therein. Thus, the reformed gas is led to the CO selective oxidation unit 24 with the carbon monoxide concentration reduced.

  The CO selective oxidation unit 24 generates carbon dioxide by reacting carbon monoxide remaining in the reformed gas with CO purification air further supplied from the outside using a catalyst filled therein. . Thereby, the reformed gas is led to the fuel electrode 11 of the fuel cell 10 with the carbon monoxide concentration further reduced (10 ppm or less).

  A condenser 30 is provided in the middle of a pipe 64 that connects the CO selective oxidation unit 24 of the reformer 20 and the fuel electrode 11 of the fuel cell 10. The condenser 30 is an integral structure in which a reformed gas condenser 31, an anode offgas condenser 32, and a cathode offgas condenser 33 are integrally connected. The reformed gas condenser 31 condenses water vapor in the reformed gas supplied to the fuel electrode 11 of the fuel cell 10 flowing in the pipe 64. The anode off-gas condenser 32 is provided in the middle of a pipe 65 that connects the fuel electrode 11 of the fuel cell 10 and the burner 21 of the reformer 20, and the fuel electrode 11 of the fuel cell 10 that flows in the pipe 65. Water vapor in the anode off-gas discharged from is condensed. The cathode offgas condenser 33 is provided downstream of the humidifier 14 in the discharge pipe 62, and condenses the water vapor in the cathode offgas discharged from the air electrode 12 of the fuel cell 10 flowing in the discharge pipe 62. The condenser 30 is supplied with a low-temperature liquid in a hot water tank (not shown) or a liquid cooled by a radiator and a cooling fan, and condenses water vapor in each gas by heat exchange with the liquid. ing.

  Each of these condensers 31, 32, and 33 is disposed below the fuel cell 10 and above the deionizer 40. Each of the condensers 31, 32, and 33 communicates with the pure water device 40 through a pipe 66. The pipe 66 has a structure in which the liquid flowing inside falls down by its own weight without collecting up to the pure water device 40. The condenser 30 may be configured to include at least the cathode offgas condenser 33. This is because the most recovered water is condensed and recovered.

  The deionizer 40 converts the water supplied from the condenser 30 and the combustion gas condenser 34, that is, recovered water, into pure water. As shown in FIG. 2, the deionizer 40 includes a housing 41 formed in a U shape that opens upward. The housing 41 includes left and right cylinders 41a and 41b and a connecting portion 41c that communicates the lower portions of both cylinders 41a and 41b. The insides of the left and right cylinders 41a and 41b and the connecting portion 41c are U-shaped spaces that open upward, and this space functions as a passage 42 through which recovered water is circulated. A filling portion 43 is formed in which the antibacterial agent 43b is mixed and filled in the resin 43a so as to be uniform. The U-shaped passage 42 is configured such that recovered water flows through the filling portion 43 by its own weight.

  The ion exchange resin 43a and the antibacterial agent 43b are formed in a granular shape. In FIG. 2, the filling portion 43 is schematically described, and the ion exchange resin 43 a is darkly colored (gray) so that the description of the shape of the particles is omitted, and the antibacterial agent 43 b is described by a large black circle. In addition, the fact that one kind of particles (ion exchange resin 43a) is uniformly filled with other kinds of particles (antibacterial agent 43b) is called mixed bed.

  In the left and right cylinders 41a and 41b, a filter 44 that also serves as a pressing member that holds and holds the upper surface of the filling portion 43 is abutted and fixed. The filter 44 filters the passing liquid, and is formed in a mesh shape or many small holes are formed.

The ion exchange resin 43a is formed by collecting cations (cations: Na ⁺ , Ca ²⁺ , Mg ^2+, etc.) and anions (anions: Cl ⁻ , HCO ₃ ⁻ ) from recovered water (or tap water) that is raw water flowing through the filling section 43. And the like, and the resin is composed of a chemically inactive portion of a resin substrate and an ion exchange group. The ion exchange resin 43a of the present embodiment includes a cation exchange resin that exchanges cations in raw water with H ⁺ and an anion exchange resin that exchanges anions in raw water with OH ⁻ (both are formed in a granular form. ) Is a mixed bed type. The mixing ratio of the cation exchange resin and the anion exchange resin is optimally designed depending on the balance of the anion and cation of the condensed water, but is usually about 1: 1.5 to 1: 2. Moreover, the particle size of both general resin is 580-680 micrometers.

  The antibacterial agent 43b is formed in a granular form having an antibacterial action, and in the present embodiment, a powder (fine particles) of a substance such as a metal or a resin having an antibacterial action is fixed to activated carbon which is a granular base material. Is configured. Activated carbon adsorbs and removes chlorine in tap water. The powder (fine particles) is preferably fixed so as not to block the micropores of the activated carbon as much as possible. This is because the adsorption effect of the activated carbon is not reduced. Specifically, the antibacterial agent 43b is formed by adhering silver powder to activated carbon, and the particle size of the activated carbon is 2.36 to 0.50 mm, and the silver content is 0.1%. . When the antibacterial agent 43b is placed in the liquid, silver is eluted in the liquid, thereby causing an antibacterial action within a predetermined range in the liquid.

  The open end of the introduction part 45 formed in the bottomed cylindrical body is liquid-tightly connected to the upper end of the right cylinder 41b (one end of the passage 42). An inlet 45 a 1 connected to a pipe 66 for introducing recovered water supplied from the condenser 30 and a pipe 63 for introducing recovered water supplied from the combustion gas condenser 34 to the top wall 45 a of the introduction part 45. There is provided an inlet 45a3 connected to a connected inlet 45a2 and a tap water supply pipe 67 (described later) for introducing tap water (make-up water) supplied from a tap water supply source (not shown) (for example, a water pipe). It has been. The top wall 45a is formed with an air vent hole 45a4.

  Further, a water reservoir 50 is integrally formed at the upper end of the left cylinder 41a (one end of the passage 42). The water reservoir 50 includes a housing 51 formed in a bottomed cylindrical body, and an open end of the housing 51 is liquid-tightly connected to an upper end of the left cylindrical body 41a. An air vent 51a1 is provided in the top wall 51a of the housing 51, and when the recovered water is supplied to the introduction part 45, the right cylinder 41b and the left cylinder 41a are filled and the water is stored in the water reservoir 50. The An overflow port 52 to which the other end of the drain pipe whose one end communicates with the outside is connected is provided in the upper part of the housing 51. When the water level of the left cylinder 41a rises and exceeds the overflow port 52, the overflow port 52 and It drains to the outside through the drain pipe.

  A pump 53 is mounted and fixed on the top wall 51a of the housing 51, and a suction pipe 53a having a lower end extending to the bottom of the water reservoir 50 (near the opening end of the housing 51) is disposed. The upper end of 68 is connected, and the lower end of a pipe 69 whose upper end is connected to the reforming unit 22 is connected to the discharge port 53 b of the pump 53. At the lower end of the water intake pipe 68, a water intake portion 54 in which many small holes are formed is fixed. Furthermore, a conductivity sensor 55 a that is disposed in the collected water stored in the water reservoir 50 and detects the conductivity of the collected water is supported and fixed by a support portion 55 b that is fixed to the lower portion of the housing 51. The conductivity sensor 55a is disposed in the vicinity of the water intake 54.

  On the top wall 51a of the housing 51, a water level gauge 56 capable of detecting the upper limit and the lower limit water level in the water reservoir 50 is attached and fixed. When the water level meter 56 detects the lower limit water level, supply of water to the pure water device 40, for example, supply of tap water, is started, and when the water level meter 56 detects the upper limit water level, supply of water to the pure water device 40, for example, supply of tap water. Is supposed to stop. The upper limit water level is set at a position slightly higher than the overflow line, and the lower limit water level is set at a position slightly higher than the intake section 54. In addition, the water level in the pure water device 40 and the water reservoir 50 is at substantially the same level as shown in FIG.

  The tap water supply pipe 67 constitutes tap water supply means for supplying tap water to the filter 44 provided in the recovered water system. As shown in FIG. 1, one end of the tap water supply pipe 67 is a filter. The other end is connected to a tap water supply source (for example, a water pipe). It is desirable that one end of the tap water supply pipe 67 is arranged so as to open facing the filter 44 and that the tap water flowing out from one end of the tap water supply pipe 67 covers the filter 44. The tap water supply pipe 67 is provided with an open / close electromagnetic valve 67 a for opening and closing the tap water supply pipe 67. The open / close electromagnetic valve 67a is supply means for supplying tap water in an adjustable manner. The open / close electromagnetic valve 67a is connected to the control device 80, and the control device 80 controls the open / close electromagnetic valve 67a to supply a predetermined amount of tap water periodically (every predetermined time). Since tap water is pumped from a tap water supply source at a predetermined water pressure, the supply amount may be determined in consideration of the opening / closing time of the open / close electromagnetic valve 67a and the predetermined water pressure. The predetermined time is preferably set according to the relationship between the operation time and the stop time of the fuel cell system, the continuous operation time, the continuous stop time, the ambient temperature of the place where the system is used, the power generation time, the power generation amount, etc. . The predetermined amount to be supplied is desirably set to an amount sufficient to sterilize the filter 44.

  The tap water supply pipe 67 may be further provided with a pump for further boosting the tap water and pumping it to the pure water device 40. In this case, the pump and the open / close electromagnetic valve 67a constitute supply means for supplying tap water in an adjustable manner. The pump and the open / close electromagnetic valve 67a are connected to the control device 80, and the control device 80 controls the pump and the open / close electromagnetic valve 67a so as to supply a predetermined amount of tap water every predetermined time.

  The recovered water system is for recovering the condensed water in the fuel cell system and purifying it, and is composed of the condenser 30, the pipe 66, and the pure water device 40. The tap water supply means includes a tap water supply pipe 67, a supply means that is provided in the tap water supply pipe 67 to supply tap water in an adjustable manner, and a control that controls the supply of tap water by the supply means. Means (control device 30).

  Next, the operation of the fuel cell system configured as described above will be described. During operation of the fuel cell system, the recovered water condensed and recovered by the condenser 30 and the combustion gas condenser 34 flows through the pipes 66 and 63 to the deionizer 40 immediately downstream by its own weight. The recovered water that has flowed into the introduction part 45 of the deionizer 40 flows in the right cylinder 41b from the top to the bottom due to its own weight, and flows into the left cylinder 41a through the connection part 41c. Due to its own weight, the water surface of the left cylinder 41a and the right cylinder 41b flows from the bottom to the top in the left cylinder 41a to the same extent (there is a water level difference corresponding to the pressure loss of the deionizer 40). Then, the water reservoir 50 is reached. That is, the recovered water in the pure water device 40 reaches the water reservoir 50 directly downstream through the filling portion 43 by its own weight and is stored. The stored recovered water is purified by an ion exchange resin 43a. The recovered water stored in the water reservoir 50 is supplied to the reformer 20 by a pump 53 by a predetermined amount corresponding to the load of the fuel cell. In addition, there is a possibility that water droplets may be generated in the pipe from the fuel cell 10 to the condenser 30. Even if water droplets are generated, the fuel cell 10 is installed above the condenser 30 and is condensed from the fuel cell 10. Since the pipe up to the vessel 30 is also configured so that the fluid inside thereof flows down by its own weight, the liquid of the fuel cell 10 flows down to the condenser 30 immediately downstream through the pipe.

  In such a flow of recovered water, in the pure water device 40 and the water storage device 50, the amount of liquid flowing into the introduction part 45 of the pure water device 40 becomes larger than the amount supplied to the reformer 20. If the water level becomes higher than the overflow port 52, the water is discharged to the outside through the overflow port 52 and the drain pipe. Further, the water level in the water reservoir 50 is monitored by a water level sensor 56 and is between the upper limit water level and the lower limit water level. As a result, the water levels in the pure water device 40 and the water reservoir 50 become substantially the same level as shown in FIG. 2, and the filling portion 43 and the filter 44 are always immersed in the liquid. In addition, since the antibacterial action extends from the antibacterial agent 43b in the filling portion 43 to a predetermined range of liquid, the liquid passing through or staying in the range or an object in the range is antibacterial.

  Further, when the tap water is supplied to the pure water device 40, the tap water is directly supplied to the recovered water stored in the introduction part 45 of the right cylinder 41b.

  As can be understood from the above description, in this embodiment, during operation of the fuel cell system, the recovered water is collected by the filter 44 disposed between the condenser 30 and the filling portion 43 of the deionizer 40. While being filtered, clogging occurs due to foreign matter collected in the filter 44, and the flow of the liquid slows down, and there is a risk that microorganisms will propagate in the site. Since water is supplied, the propagated microorganisms can be sterilized by residual chlorine in tap water. According to this, it is possible to suppress the growth of microorganisms in the recovered water with little change to the conventional system, that is, without increasing the number of parts, without increasing the size of the entire system, and without increasing the cost. Thus, a fuel cell system that can realize long-term operation can be provided.

  The deionizer 40 is configured such that the filling portion 43 is always immersed in the liquid in the deionizer 40, the filter 44 is disposed in the liquid, and the tap water supply means supplies the tap water to the liquid. . As a result, the supplied tap water diffuses into the liquid in the pure water device 40 and is uniformly supplied to the filter 44 disposed in the liquid. Therefore, the effect of the sterilization effect of the filter 44 by tap water can be further improved.

  Further, since the control device 80 controls the supply means (pump and open / close electromagnetic valve 67a) so as to supply a predetermined amount of tap water every predetermined time, the filter 44 can be efficiently sterilized and sterilized. It is possible to save the tap water used.

  Moreover, since the filling part 43 is further filled with the antibacterial agent 43b, the filling part 43 can be more reliably antibacterial by the antibacterial action of the antibacterial agent 43b in addition to the sterilization action of tap water.

  Moreover, since the filling part is further filled with activated carbon (antibacterial agent 43b), it is possible to prevent the residual chlorine content of tap water from being removed by activated carbon and supplied downstream of the pure water device 40. Moreover, deterioration of the ion exchange resin due to residual chlorine can be suppressed. Moreover, since installation of another apparatus for removing the chlorine content of tap water can be omitted, it is possible to prevent an increase in the number of parts, an increase in the size of the entire system, and an increase in cost.

  In addition, since the holding member that holds and holds the filling portion 43 is used as the filter 44, it is possible to achieve filtration in the recovered water without installing a filter as a separate member. Can be prevented from increasing in size and cost.

  The present invention is not only applied when supplying tap water to the filling unit 43 of the deionizer 40, but also when supplying tap water to any part as long as it is on the recovered water system. it can. In particular, it may be supplied directly to a site where microorganisms are likely to propagate. According to this, since tap water is regularly supplied by the tap water supply means to a part on the recovered water system where there is a possibility that microorganisms will propagate such as a part where clogging occurs and the flow of the liquid becomes slow, Microorganisms propagated by residual chlorine in tap water can be periodically sterilized. Therefore, by hardly changing the conventional system, that is, without increasing the number of parts, without increasing the size of the entire system, and without increasing the cost, by suppressing the growth of microorganisms in the recovered water, A fuel cell system capable of realizing long-term operation can be provided.

  In the above embodiment, the passage 42 of the deionizer 40 filled with the filling portion 43 is formed in a U-shape opened to the top, and when the liquid is accumulated in the passage 42, the filling portion 43 is Although it was always immersed in the liquid, instead of this structure, another structure in which the filling portion 43 is immersed in the liquid may be used.

  In the above embodiment, the case where the recovered water is purified and used as reformed water is applied. However, as disclosed in Japanese Patent Application Laid-Open No. 2003-151591, the fuel electrode and the air of the fuel cell are used. The present invention may be applied to the case where the purified water supplied to the electrode is supplied to the humidifier that humidifies the reformed gas and air.

  Moreover, in the said embodiment, you may make it attach a structure which sprinkles tap water efficiently to the introduction end of the tap water supply pipe 67, ie, the water storage part of the introduction part 45. As an example of this structure, there is a structure in which a plate member is disposed directly below the introduction port 45a3 so as to face the opening, and tap water is once received by the plate member and dropped from the edge of the plate member.

  In the above embodiment, the present invention is applied to the case where the recovered water recovered in the fuel cell system is used as reformed water. However, the amount of recovered water decreases during operation of the fuel cell system, and is externally applied. The present invention can also be applied to the case where tap water is replenished, and can also be applied to the case where tap water is not replenished on the way without reducing the amount of recovered water.

1 is a schematic diagram showing an outline of an embodiment of a fuel cell system according to the present invention. It is sectional drawing which shows the pure water device and the water reservoir shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 11 ... Fuel electrode, 12 ... Air electrode, 20 ... Reformer, 21 ... Burner, 22 ... Reformer, 23 ... Carbon monoxide shift reaction part (CO shift part), 24 ... Carbon monoxide Selective oxidation reaction section (CO selective oxidation section), 30 ... condenser, 31 ... reformed gas condenser, 32 ... anode offgas condenser, 33 ... cathode offgas condenser, 34 ... combustion gas condenser, 40 DESCRIPTION OF REFERENCE SIGNS ...... Pure water purifier 41 ... housing 41a, 41b ... cylindrical body 41c ... connecting part 42 ... passage 43 ... filling part 43a ... ion exchange resin 43b ... antibacterial agent 44 ... filter 45 ... introducing part 45a1, 45a2, 45a3 ... inlet port, 46 ... outlet part, 46a1 ... air vent hole, 46b ... outlet port, 50 ... reservoir, 51 ... housing, 52 ... overflow port, 53 ... pump, 54 ... water intake part, 55a ... conductivity center Sa, 56 ... water level indicator, 57 ... tank, 61～66,68,69 ... piping, 67 ... tap water supply pipe, 67a ... off solenoid valve, 80 ... control unit.

Claims (6)

A condenser that condenses at least water vapor in exhaust gas sent from the fuel electrode or air electrode of the fuel cell and collects it as recovered water;
An introduction portion provided with an introduction port for introducing the recovered water supplied from the condenser; and a filling portion that is connected to the introduction portion and filled with an ion exchange resin that purifies the recovered water. A fuel provided with a recovered water system having at least a deionizer comprising a passage and a lead-out portion connected to the other end of the passage and provided with a lead-out port through which the recovered water purified through the passage is led In battery systems,
A fuel cell system, further comprising tap water supply means for periodically supplying tap water to the recovered water system. 2. The tap water supply means according to claim 1, wherein the tap water supply means has one end connected to the recovered water system and the other end connected to a tap water supply source, and the tap water supply means is interposed in the tap water supply pipe. And a control means for controlling the supply of tap water by the supply means,
The fuel cell system characterized in that the control means controls the supply means so as to supply a predetermined amount of tap water every predetermined time. In claim 2, the recovered water system is
A filter that is disposed between the condenser and the filling unit and filters the recovered water;
The fuel cell system, wherein the tap water supply means supplies tap water to at least the filter.   4. The pure water device according to claim 3, wherein the filling unit is configured so that the filling portion is always immersed in the liquid in the pure water device, the filter is disposed in the liquid, and the tap water supply means is the tap water. Is supplied to the liquid.   The fuel cell system according to any one of claims 1 to 4, wherein the filling portion is further filled with an antibacterial agent. 5. The fuel cell system according to claim 1, wherein the filling portion is further filled with activated carbon. 6.

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