JP2690896B2 - Multi-tube steam electrolyzer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-tubular steam cracking apparatus for electrolyzing steam using a plurality of solid electrolyte cells. [Prior Art] In a fusion reactor system, tritium as a fuel is converted into tritiated water and recovered in various processes. For example, breeding tritium contained in blanket cooling gas or sweep gas, impurities containing tritium in plasma exhaust gas are subjected to catalytic oxidation and adsorption, and cooling operation,
After separation and recovery as tritiated water, it is necessary to return this to the chemical form of hydrogen by an appropriate method and use it as a fuel. As a tritium water decomposition method, application of a gas phase decomposition method such as an aqueous gas conversion reaction method (catalytic reduction method) or an active metal reduction method, and a wet decomposition method such as a solid polymer electrolyte electrolysis method are considered. The vapor phase decomposition method has many advantages such as a small inventory of tritium, continuous operation, and relatively low operating temperature. However, the hydrogen gas conversion reaction method has a problem that reducing gas is mixed into hydrogen (tritium) as a by-product. Further, in the active metal reduction method, the active metal forms metal oxides and is consumed,
It has a principle drawback such as generation of radioactive solid waste.
The wet method is a technology that is widely applied industrially, but as a high-concentration tritium water splitting method, it is a batch operation with a very large tritium inventory. There arise problems such as prevention of mixing of water vapor into the electrolysis gas (hydrogen and oxygen) and complete separation of hydrogen and oxygen from each other. In particular, the polymer decomposition method cannot avoid deterioration of the material due to radiation. On the other hand, by applying voltage to the inner and outer surfaces, the tritium water splitting method using a solid electrolyte cell having oxygen (or hydrogen) permeability can satisfy all the conditions required for the high concentration tritium water splitting method. That is, since the cell is composed of ceramic (main body) and noble metal (electrode (not shown)), there is little risk of radiation damage, corrosion, deterioration and tritium penetration. Also, since it is electrolysis of water vapor, continuous treatment in the gas phase is possible, and the tritium inventory is extremely small. Furthermore, the electrolysis product oxygen is
Since the electrolyte is a conductor that allows only oxygen ions to pass through, it is completely separated from hydrogen (tritium) and tritium water vapor, and there is little risk of tritium contamination, which is another characteristic not found in other methods. Regarding the effectiveness of the tritium decomposition method using a solid electrolyte cell, the inventors have already demonstrated a single-tube structure using a real gas (pure tritium vapor T ₂ O). By the way, as a steam electrolyzer using a solid electrolyte cell, a structure shown in FIG. 8 is conventionally known. That is, reference numeral 1 in the drawing is a container as an apparatus main body having a flange 2 on the upper portion thereof, and a lid 3 is fixed to the flange 2 of the container 1 by bolts, nuts or the like. A vacuum heat insulating tank 4 is provided on the outer circumference of the side wall of the container 1.
Further, a solid electrolyte cell 5 is suspended from the lid 3 in the container 1. A water vapor introducing pipe 6 is inserted in the solid electrolyte cell 5, and the introducing pipe 6 is fixed by a U-shaped flange portion 7 provided on the lid body 3. An exhaust pipe 8 for hydrogen isotope gas is connected to the flange portion 7. In addition, the solid electrolyte cell 5
A heater block (for example, a cylindrical shape) 9 and a bottomed cylindrical heat shield body 10 are sequentially arranged in a concentric pattern at predetermined intervals on the outer periphery of the. An annular heat shield plate 11 is arranged above the heat shield body 10. Further, an oxygen exhaust pipe 12 is connected to the lid 3, and a vacuum evacuation pipe 13 is connected to the vacuum heat insulating tank 4. A water cooling jacket may be used instead of the vacuum heat insulating tank 4. In this case, a cold water supply pipe is used instead of the evacuation pipe 13. In the electrolyzer having such a structure, when the solid electrolyte cell 5 is heated to 500 to 600 ° C. (1000 ° C. if necessary) by the heater block 9 and then steam is supplied into the steam introducing pipe 6, the solid electrolyte cell 5 causes hydrogen to be generated. It is decomposed into isotopes and oxygen and taken out through the exhaust pipes 8 and 12, respectively, and water vapor is decomposed. [Problems to be Solved by the Invention] In the above-described conventional electrolyzer, the solid electrolyte cell 5 is used.
It is considered that the temperature of the solid electrolyte cell 5 itself in the circumferential direction becomes substantially uniform due to the heating of the heater block 9 when the number of cells is several. In the vertical direction of the solid electrolyte cell 5, it is easy to make the temperature uniform by appropriately selecting the length of the heater block 9. However, when the number of the solid electrolyte cells 5 increases, the radius of the container 1 also naturally increases, so that when heating with the heater block 9, the radiation surface facing the heater block 9 in the circumferential direction of the solid electrolyte cell 5 itself. There is a considerable temperature difference between the side and the opposite side. Since the steam decomposition performance of the solid electrolyte cell 5 is greatly influenced by its own temperature, if the temperature differs by 100 ° C., the steam decomposition performance will differ by about one digit. The present invention has been made to solve the above-mentioned conventional problems, and makes the temperature distribution in the circumferential direction of each individual solid electrolyte cell uniform, and minimizes the variation in temperature between the individual solid electrolyte cells. It is an object of the present invention to provide a multi-tube steam electrolyzer capable of suppressing steam and uniformly electrolyzing steam supplied from a common steam supply source such as a manifold in all solid electrolyte cells. [Means for Solving Problems] A multitubular steam decomposing apparatus according to the present invention includes a plurality of bottomed tubular solid electrolyte cells loaded in an apparatus body,
A heater disposed around the plurality of solid electrolyte cells, each of the solid electrolyte cells is supplied with water vapor from a common water vapor supply source to decompose the water vapor, and oxygen generated is generated by each of the solids. In a multi-tubular steam electrolyzer for permeating and discharging the wall of an electrolyte cell, the outer periphery of each solid electrolyte cell, soaking tubes are arranged concentrically with the solid electrolyte cell at a predetermined distance. It is a feature. Another multitubular steam electrolysis apparatus according to the present invention includes a plurality of bottomed tubular solid electrolyte cells loaded in the apparatus main body, and a heater disposed around the plurality of solid electrolyte cells. In a multi-tubular steam electrolyzer for supplying steam from a steam supply source common to each solid electrolyte cell to decompose the steam, and discharging generated oxygen through the wall of each solid electrolyte cell. Each of the solid electrolyte cells is inserted into an oxidation-resistant metal block having the heater arranged on the outer periphery thereof. [Operation] According to the present invention, soaking tubes are concentrically arranged on the outer periphery of a plurality of bottomed tubular solid electrolyte cells with a predetermined distance therebetween, and heaters are arranged around the plurality of solid electrolyte cells. By providing, it is possible to maintain a uniform temperature distribution in the circumferential direction of each solid electrolyte cell, it is possible to uniformly electrolyze the steam supplied from a common steam supply source in all solid electrolyte cells A multi-tube steam decomposition apparatus can be provided. Further, according to the present invention, a plurality of solid electrolyte cells each having a bottomed tubular shape are inserted into an oxidation-resistant metal block, and a heater is arranged on the outer periphery of the metal block, thereby forming a circle of the solid electrolyte cell. It is possible to provide a multi-tube steam decomposition apparatus capable of maintaining a uniform temperature distribution in the circumferential direction and uniformly electrolyzing steam supplied from a common steam supply source in all solid electrolyte cells. . [Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. The same members as those in FIG. 8 described above are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 14 in the drawing is a soaking tube which is concentrically arranged on the outer periphery of each solid electrolyte cell 5 at a predetermined interval. These heat equalizing tubes 14 are formed of a metal that is hard to oxidize such as a SUS or Cu tube plated with Ni. Further, a quartz tube 15 as an insulating material is arranged between each of the solid electrolyte cells 5 and the soaking tube 14 as shown in FIG. 3 in order to prevent an electrical short circuit. According to the multi-tube steam electrolysis apparatus having such a configuration, since the soaking tubes 14 are arranged on the outer periphery of each solid electrolyte cell 5, the heat from the heater block 9 is passed through each soaking tube 14 to cause the solid electrolyte cells 5 to flow. Therefore, the temperature distribution in the circumferential direction in each cell 5 can be made uniform. As a result, a uniform steam decomposition performance can be exhibited in each solid electrolyte cell 5. Further, by disposing the quartz tube 15 having good heat transfer property and excellent heat resistance between the solid electrolyte cell 5 and the soaking tube 14, the processing accuracy and the assembly accuracy of the solid electrolyte cell 5 and the soaking tube 14 are slightly increased. At the worst, since the quartz tube 15 has a structure interposed between them, it is possible to assemble a disassembling apparatus having a predetermined performance with electrical insulation. When the number of solid electrolyte cells is further increased in the above-mentioned embodiment, the solid electrolyte cells 5 near the center of the container 1 far from the heater block 9 and the cells 5 close to the heater block 9 are considerably large. There may be a temperature difference. In such a case, another heater block 16 is provided at the center of the container 1 as shown in FIGS. 4 to 6, and the temperature of each solid electrolyte cell 5 is controlled by controlling the temperature of the heater block 16. Variations can be minimized. FIG. 7 is a schematic view of a main part of a multitubular steam decomposing apparatus showing another embodiment of the present invention. In this multi-tube steam decomposition apparatus, an oxidation-resistant metal block 19 is arranged in a container 1. Inside the metal block 19, a plurality of bottomed tubular solid electrolyte cells 5 are inserted. A micro heater (or a rod-shaped heater) 20 is arranged on the outer periphery of the metal block 19. In the multitubular steam decomposing apparatus having such a configuration, the metal block 19 acts as a heat medium by generating heat from the microheater 20, so that the metal block
The plurality of solid electrolyte cells 5 inserted in 19 can be heated uniformly. Further, in the above-mentioned embodiment, the electrolysis device using the oxygen-conductivity type electrolysis cell has been described, but it can be similarly applied to the electrolysis device having the same kind of function such as the hydrogen-conduction type electrolysis cell. [Effects of the Invention] As described in detail above, according to the present invention, the temperature distribution in the circumferential direction of the solid electrolyte cell can be made uniform, and the variation in temperature between the cells can be minimized, and the steam decomposition performance can be improved. It is possible to provide a multi-tube steam decomposing apparatus that can achieve higher efficiency and can reduce the number of cells, and thus can reduce not only the manufacturing cost but also the cost of control-related equipment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a multi-tube steam decomposing apparatus showing an embodiment of the present invention, FIG. 2 is a view taken along the line AA of FIG. 1, and FIG. 4 is a schematic view of a multi-tube steam decomposing apparatus showing another embodiment of the present invention, and FIG. 5 is A of FIG.
-A arrow view, FIG. 6 is a BB arrow view of FIG. 4, FIG. 7 is a schematic view of a main part showing a multi-tube steam decomposing apparatus showing another embodiment of the present invention, and FIG. FIG. 3 is a schematic view showing a conventional multi-tube steam decomposition apparatus. 1 ... Vessel (apparatus main body), 3 ... Lid, 5 ... Solid electrolyte cell, 6 ... Steam introduction pipe, 8 ... Hydrogen isotope gas exhaust pipe, 9, 16 ... Heater block, 10 ... … Heat shield, 12 …… Oxygen exhaust pipe, 14 …… Soaking pipe, 15 …… Quartz pipe (insulating material), 17… Tube heater (pipe heater),
18 …… Rod heater, 19 …… Metal block, 20 …… Micro heater.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Kenji Muta               1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi               Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Junzo Amano               1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi               Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Takeshi Watanabe               5-1-1 Komatsu-dori, Hyogo-ku, Kobe               Ceremony company Shinryo Hi-Tech                (56) Reference JP-A-58-34183 (JP, A)

Claims (1)

(57) [Claims] A plurality of bottomed tubular solid electrolyte cells loaded in the apparatus main body and a heater arranged around the plurality of solid electrolyte cells are provided, and steam is supplied from a steam supply source common to the respective solid electrolyte cells. In the multi-tubular steam electrolyzer to supply water to decompose the water vapor, and to discharge the generated oxygen through the wall of each solid electrolyte cell, the outer periphery of each solid electrolyte cell is separated by a predetermined distance. A multitubular steam electrolyzer, wherein the soaking tubes are respectively arranged concentrically with the solid electrolyte cells. 2. The multitubular steam electrolysis apparatus according to claim 1, wherein a tubular insulating material is arranged between the solid electrolyte cell and the soaking tube. 3. The multi-tube steam electrolysis apparatus according to claim 1, wherein another heater is arranged in the center of the apparatus main body. 4. A plurality of bottomed tubular solid electrolyte cells loaded in the apparatus main body and a heater arranged around the plurality of solid electrolyte cells are provided, and steam is supplied from a steam supply source common to the respective solid electrolyte cells. In a multi-tubular steam electrolysis apparatus for respectively performing decomposition of water vapor and discharging generated oxygen through the wall of each solid electrolyte cell, wherein each solid electrolyte cell has the heater arranged on the outer periphery thereof. A multi-tube steam electrolyzer characterized by being inserted in each of the provided oxidation-resistant metal blocks.