JP2005289740A - Thermochemical hydrogen producing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide thermochemical hydrogen producing equipment which does not induce precipitation of iodine when heat supply from a heat source is stopped or when operation of the hydrogen producing equipment is stopped. <P>SOLUTION: The equipment is equipped with: a heat source; a first piping system to transport a first fluid; a second piping system L6, L7 to transport a second fluid, an intermediate heat exchanger to heat exchange the first and second fluids; a sulfuric acid vaporizing and decomposing part 8 and a hydrogen iodide decomposing part 9 to exchange heat with the second fluid; a reactor 10; heat exchange piping L8 to heat exchange the sulfuric acid vaporizing and decomposing part 8 and the hydrogen iodide decomposing part 9; a third piping system L61, L62 to transport a third fluid; a heat exchanger 6 to impart the heat of the second fluid into the third fluid; a first valve V1 to control the distribution of the flow rate to the heat exchanger 6 and to the second piping system; a third fluid introducing piping system L14 to introduce the third fluid into hydrogen iodide transporting piping L22 directing to the hydrogen iodide decomposing part 9; a second valve V2 to control the flow rate of the third fluid; and a connecting part V3 which makes the third fluid join the hydrogen iodide flowing in the hydrogen iodide transporting piping L22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermochemical hydrogen production facility for producing hydrogen using a thermochemical method (IS method or SI method).

  As one of the hydrogen production facilities, a thermochemical hydrogen production facility using a thermochemical method (IS method or SI method) has been devised. As such a thermochemical hydrogen production facility, for example, as disclosed in Patent Document 1, hydrogen iodide and sulfuric acid are produced by reaction of iodine, sulfur dioxide and water, and hydrogen iodide is decomposed. In addition to producing iodine and hydrogen, sulfuric acid is heated to a temperature between 335 ° C. and 950 ° C. to evaporate and decompose to produce sulfur dioxide and oxygen. Hydrogen and oxygen are recovered, and iodine and sulfur dioxide are re-watered. There is equipment for a hydrogen production process, generally called the IS process.

Further, as a heat source necessary for decomposing sulfuric acid in such a hydrogen production facility, use of a high-temperature gas furnace as in Non-Patent Document 1, for example, has been studied.
Shoko 60-52081 http://httrntsy.oarai.jacri.go.jp/index_top.html

  In the thermochemical hydrogen production facility using the IS method described above, since the melting point of iodine is about 114 ° C., when the gas or solution containing iodine becomes 114 ° C. or lower, iodine in the reaction vessel or in the piping, valves, and pumps. This may cause problems in the operation of the hydrogen production plant, and temperature management of the plant and measures against iodine precipitation when the plant is stopped have been problems.

  The present invention has been made in order to solve the above-described problems, and is capable of returning the equipment to room temperature without causing iodine precipitation when the supply of heat from the heat source is stopped and when the hydrogen production equipment is stopped. The purpose is to obtain a hydrogen production facility.

  The thermochemical hydrogen production facility of the present invention includes a heat source 2, first piping systems L2 to L5 that transport a first fluid that exchanges heat with the heat source 2, and a second piping that transports a second fluid. An intermediate heat exchanger 4 connected to the systems L6, L7, and the first piping system L3 and the second piping system L7, respectively, for exchanging heat between the first fluid and the second fluid; A sulfuric acid evaporative decomposition unit 8 that exchanges heat with the second fluid to evaporate and decompose sulfuric acid, a hydrogen iodide decomposition unit 9 that exchanges heat with the second fluid to separate and decompose hydrogen iodide, and the sulfuric acid A reactor 10 connected to the evaporative decomposition unit 8 and the hydrogen iodide decomposition unit 9 via a separator, respectively, to react with sulfur dioxide, iodine and water to produce sulfuric acid and hydrogen iodide; and the second piping system L6 and L7 are upstream of the portion in contact with the sulfuric acid evaporative decomposition portion 8 and upstream. A heat exchange pipe L8 that branches from the second piping systems L6 and L7 and exchanges heat with the sulfuric acid evaporative decomposition section 8 and the hydrogen iodide decomposition section 9 respectively, and a third piping system L61 that transports a third fluid. , L62 and the heat exchanger 6 connected to the heat exchange pipe L8 via the second pipe systems L6, L7, and applying the heat of the second fluid to the third fluid, and the second The heat exchange pipe L8 is branched from the pipe systems L6, L7, and the flow rate of the second fluid to the heat exchanger 6 and the flow rate of the second fluid to the second pipe system are provided. The first valve V1 that adjusts the distribution of the water and the third piping system L62 on the outlet side of the heat exchanger 6 of the third piping system, branching from the third piping system L62 to the hydrogen iodide decomposition section 9 A third fluid introduction pipe L14 for introducing the third fluid into the hydrogen fluoride transport pipe L22; The third fluid introduction pipe L14 is provided where the third pipe system L62 branches, the second valve V2 for adjusting the flow rate of the third fluid, and the third fluid introduction pipe L14. A connection portion V3 provided at a place connected to the hydrogen iodide transport pipe L22 and joining the third fluid to hydrogen iodide flowing in the hydrogen iodide transport pipe L22, and for discharging waste The waste treatment facility 16 connected to the reactor 10 via the discharge pipe L15, the downstream side of the portion where the heat exchange pipe L8 is in contact with the sulfuric acid evaporative decomposition section 8, and the heat exchange pipe L8 A bypass pipe L13 connected to the upstream side of the portion in contact with the hydrogen iodide decomposition unit 9 and bypassing the second fluid to the hydrogen iodide decomposition unit 9 without exchanging heat with the sulfuric acid evaporation decomposition unit 8; The above A bypass pipe L13 is provided where the second pipe system L6 branches, and the flow rate of the second fluid to the bypass pipe L13 and the flow rate of the second fluid to the second pipe system are A fourth valve V4 for adjusting the distribution and a fifth valve for adjusting the flow distribution flowing from the bypass pipe L13 to the heat exchange pipe L8, provided where the bypass pipe L13 joins the heat exchange pipe L8. And V5.

  In the thermochemical method (IS method), the reaction for hydrogen generation proceeds according to the following reaction formulas (1), (2), and (3).

2H ₂ O + SO ₂ + 3I ₂ = H ₂ SO ₄ + 2HI ₃ (1)
H ₂ SO ₄ → SO ₂ + 1 / 2O ₂ (2)
2HI ₃ → 3I ₂ + 3H ₂ (3)
In the reactor, the chemical reaction proceeds reversibly from the left side to the right side of the above formula (1) or from the right side to the left side under the conditions of a temperature of 100 to 120 ° C. and an atmospheric pressure to 20 atm.

  In the decomposer of the sulfuric acid evaporative decomposition section, the chemical reaction irreversibly proceeds from the left side to the right side of the above formula (2) under the conditions of a temperature of about 900 ° C. and atmospheric pressure to 20 atm.

  In the decomposer of the hydrogen iodide decomposition unit, the chemical reaction irreversibly proceeds from the left side to the right side of the above formula (3) under conditions of a temperature of about 450 ° C. and atmospheric pressure to 20 atm.

  According to the present invention, before the hydrogen production facility is stopped and returned to room temperature, it is washed with water having a temperature higher than the iodine precipitation temperature, so that the precipitation of iodine when the hydrogen production facility is returned to room temperature is effectively prevented. can do.

  Further, since the high-temperature water for cleaning is generated using the heat of the secondary system He bypassing the sulfuric acid evaporative decomposition section, no special heat source for generating the high-temperature water is required. Furthermore, since the hydrogen iodide decomposition part is maintained at a temperature higher than the iodine precipitation temperature in the secondary system He during the preparation and cleaning of the high-temperature water for washing, precipitation of iodine during the plant stoppage can be prevented. .

  Hereinafter, various exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

  First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 3 shows an example of the material flow in the thermochemical hydrogen production facility. Here, the case where a high temperature gas furnace is used as a heat source will be described as an example. However, any heat source can be used as long as heat of 850 ° C. or higher can be obtained. Can also be used as a heat source.

  First, an overview of the entire thermochemical hydrogen production facility will be described with reference to FIG.

  The thermochemical hydrogen production facility 1 includes a high-temperature gas furnace 2 as a heat source, a primary system He lines L2 to L5 for extracting heat from the high-temperature gas furnace 2, and a system for extracting heat from the primary system He lines L2 to L5. An intermediate heat exchanger 4 having a heat exchange section HE3 for exchanging heat between the secondary system He lines L6 and L7, the primary system He line L2 and the secondary system He lines L6 and L7, and the primary system He line L2 ~ Primary pressurized water cooler 5 for adjusting the heat removal amount from L5, Secondary pressurized water cooler 6 for adjusting the heat removal amount from the secondary system He line L7, and decay heat removal system at the time of reactor isolation The auxiliary cooler 7 is provided. The primary pressurized water cooler 5 and the secondary pressurized water cooler 6 are connected to a heat exchanger HE1 provided with a circulation pump P1 via lines L61 and L62 so that the primary pressurized water and the secondary pressurized water are heat-exchanged. . The auxiliary cooler 7 is connected to a heat exchanger HE2 provided with a circulation pump P2 via lines L71 and L72, and emergency emergency cooling water is supplied.

  Furthermore, the secondary system He lines L6 and L7 are connected to the heat exchange line L8 of the hydrogen production facility 1 of the present invention via the flow distribution adjusting valves V1 and V2 shown in FIG.

(First embodiment)
A thermochemical hydrogen production facility 1 according to a first embodiment of the present invention will be described with reference to FIG.
The equipment 1 of the first embodiment includes a sulfuric acid evaporative decomposition unit 8, a hydrogen iodide decomposition unit 9, a reactor 10, a two-phase separator 11, a sulfuric acid (H ₂ SO ₄ ) concentrator 12, and a secondary He bypass line. L13, high-temperature water line L14, discharge line L15, waste treatment facility 16, flow distribution adjusting valves V1, V2, V4, V5, branch valve V3 and a controller that controls each part of the facility and controls the operation of each part of the facility (FIG. Not shown).

The sulfuric acid evaporative decomposition unit 8 has a sulfuric acid (H ₂ SO ₄ ) evaporator 81 and an SO ₃ decomposer 82, and these are connected to the secondary system He lines L 6 and L 7 through the flow distribution adjusting valve V 1. It is designed to exchange heat with the exchange line L8. That is, the heat exchanging unit HE4 of the heat exchange line L8 exchanges heat with the internal fluid (sulfuric acid vapor) of the SO ₃ decomposer 82 and heats the sulfuric acid vapor to about 900 ° C. Further, the heat exchanging unit HE5 of the heat exchange line L8 exchanges heat with the internal fluid (concentrated sulfuric acid solution) of the sulfuric acid evaporator 81 to heat the concentrated sulfuric acid solution to about 500 ° C.

  The flow distribution adjusting valve V1 distributes the secondary system He, which is a heat transfer fluid, to the line L7 of the intermediate heat exchanger 4 and the heat exchange line L8 of the hydrogen production facility 1 at a desired ratio. It is controlled by a controller (not shown) in the central control room. The flow distribution adjusting valve V4 is provided where the bypass line L13 branches from the secondary system He line L6, and distributes the secondary system He to the heat exchange line L8 and the bypass line L13 at a desired ratio. The operation is controlled by a main controller (not shown) in the central control room. The downstream side of the bypass line L13 is connected so as to join the heat exchange line L8 via a valve V5 on the outlet side of the sulfuric acid evaporative decomposition unit 8.

The sulfuric acid evaporative decomposition unit 8 has circulation circuits L23 to L28 between the two-phase separator 11, the sulfuric acid concentrator 12, and the separator 13. The sulfuric acid separated by the two-phase separator 11 is sent to the sulfuric acid concentrator 12 through the line L23, and the concentrated concentrated sulfuric acid solution is sent to the sulfuric acid evaporator 81 of the sulfuric acid evaporative decomposition unit 8 through the line L24. The sulfuric acid vapor is sent to the SO ₃ decomposer 82 of the sulfuric acid evaporative decomposition section 8 through the line L25, and the decomposed sulfur dioxide and oxygen and undecomposed sulfuric acid and water are sent to the separator 13 through the line L26. After heat exchange with the line L25 and the sulfuric acid concentrator 12 in the heat exchange parts HE8 and HE9, respectively, the separator 13 separates the sulfur dioxide / oxygen and undecomposed sulfuric acid / water into the reactor 10 through the line L27. The latter is sent to the sulfuric acid concentrator 12 through the line L28. On the other hand, the hydrogen iodide separated by the two-phase separator 11 is sent to the electrolytic electrodialyzer 91 of the hydrogen iodide decomposition unit 9 through lines L21 and L22.

  The hydrogen iodide decomposition unit 9 includes an electrolytic electrodialyzer 91, a hydrogen iodide distiller 92, a hydrogen iodide decomposer 93, and a separator 94 that are sequentially connected in series. The heat exchange line L8 described above is in contact with the hydrogen iodide distiller 92 and the hydrogen iodide decomposer 93 of the hydrogen iodide decomposition unit 9 so as to be able to exchange heat on the downstream side of the valve V5. That is, the heat exchanging unit HE6 of the heat exchange line L8 exchanges heat with the internal fluid (hydrogen iodide vapor) of the hydrogen iodide decomposer 93 to heat the hydrogen iodide vapor to about 450 ° C. The heat exchange section HE7 of the heat exchange line L8 exchanges heat with the hydrogen iodide distiller 92 internal fluid (dialysis hydrogen iodide) to heat the dialysis hydrogen iodide to about 120 ° C. The separator 94 of the hydrogen iodide decomposition unit 9 separates the produced iodine from undecomposed hydrogen iodide and sends it to the reactor 10 through the line L32, and the undecomposed hydrogen iodide passes through the line L31. To return to the hydrogen iodide decomposer 93.

  The reactor 10 includes a special catalyst and an internal flow path for producing sulfuric acid and hydrogen iodide from sulfur dioxide, water and iodine. The reactor 10 is connected to the waste treatment facility 16 by a discharge line L15 without forming a circulation circuit with the hydrogen iodide decomposition unit 9 described above. The iodine-based waste accumulated in the reactor 10 is discharged from the reactor 10 to the waste treatment facility 16 by opening the on-off valve V6 during maintenance inspection.

  The two-phase separator 11 separates sulfuric acid and hydrogen iodide using the difference in specific gravity. That is, sulfuric acid as a light liquid is extracted from the top of the two-phase separator 11, and hydrogen iodide as a heavy liquid is extracted from the bottom of the two-phase separator 11.

  The sulfuric acid concentrator 12 concentrates sulfuric acid to a desired concentration by electrolyzing water contained in the sulfuric acid solution. The concentration temperature is, for example, 220 ° C.

  The secondary system He bypass line L13 is used to directly send the secondary system He to the hydrogen iodide decomposition unit 9 without passing it through the sulfuric acid evaporation decomposition unit 8 and to exchange heat with the heat exchange units HE6, 7. . The bypass line L13 branches from the secondary system He line L6 on the downstream side of the sulfuric acid evaporative decomposition unit 8 and joins the heat exchange line L8 on the upstream side of the sulfuric acid evaporative decomposition unit 8. A flow rate adjusting valve V4 is attached to a branch portion between the bypass line L13 and the secondary system He line L6, and the flow rate of the secondary system He to the bypass line L13 and the flow rate of the secondary system He to the secondary system He line L6. The flow rate is adjusted to a desired ratio. Further, a flow rate adjusting valve V5 is attached to the junction of the bypass line L13 and the heat exchange line L8, and the flow rate of the secondary system He to the bypass line L13 and the flow rate of the secondary system He to the heat exchange line L8 are adjusted. The flow rate is adjusted to a desired ratio.

  The high-temperature water introduction line L14 includes a hydrogen iodide transport line L22, a secondary pressurized water return line L62, and a high-temperature water (third fluid) generated in the secondary pressurized water cooler 6 to guide the hydrogen iodide decomposition unit 9. It is provided between. The high temperature water introduction line L14 branches off from the return line L62 of the secondary pressurized water cooler 6. A flow rate adjusting valve V2 is provided at this branch portion. The flow rate adjusting valve V2 distributes the flow rate of the high temperature water to the high temperature water introduction line L14 and the flow rate of the high temperature water to the return line L62 at a desired ratio. The operations of the flow rate adjusting valves V1, V2, V4, V5 are controlled by a main controller (not shown) in the central control room. The high temperature water introduction line L14 joins the hydrogen iodide transport line L22 on the downstream side of the two-phase separator 11 and on the upstream side of the hydrogen iodide decomposition unit 9. A three-way on-off valve V3 is provided at this junction. The opening / closing operation of the three-way opening / closing valve V3 may be synchronized with the operation of the flow rate adjusting valve V2 described above, or may be operated independently.

Next, the operation will be described.
In the hydrogen production facility 1 of the first embodiment, if the nuclear reactor and the hydrogen production facility are in normal operation, the secondary system He at 900 ° C. or higher flows through all of the heat exchange line L8 and the sulfuric acid evaporative decomposition unit 8 And each part of the hydrogen iodide decomposition part 9 are respectively heat-exchanged. That is, after the temperature of the SO ₃ decomposer 82 is raised to about 900 ° C. and the temperature of the sulfuric acid evaporator 81 is raised to about 500 ° C., the secondary system He further heats the hydrogen iodide decomposer 9 and the heat. In exchange, the Hl decomposer 93 is heated to about 450 ° C., and the Hl distiller 92 is heated to about 250 ° C., and each is maintained at a temperature suitable for the reaction.

  In the reactor 10, hydrogen iodide and sulfuric acid are generated by the reaction of iodine, sulfur dioxide, and water, and the generated hydrogen iodide and sulfuric acid are separated by specific gravity by the two-phase separator 11. The separated hydrogen iodide is sent to the electrolytic electrodialyzer 91 of the hydrogen iodide decomposition section 9 and electroelectrodialyzed at a temperature of about 120 ° C., and then distilled in the distiller 91 at a temperature of about 250 ° C. The HI decomposer 93 is heated to about 450 ° C. and thermally decomposed into iodine and hydrogen.

  The produced hydrogen is collected as a product in a container (not shown). On the other hand, the produced iodine is separated and removed from the undecomposed hydrogen iodide by the separator 94 and then sent to the reactor 10 to be subjected to a thermochemical reaction. The undecomposed hydrogen iodide is returned to the HI decomposer 92 through the return line L31 and re-decomposed.

  On the other hand, the sulfuric acid separated by the two-phase separator 11 is sent to the sulfuric acid concentrator 12 and concentrated at a temperature of about 220 ° C., and then evaporated at a temperature of about 500 ° C. in the evaporator 81 of the sulfuric acid evaporation / decomposition unit 8. Further, it is heated to about 900 ° C. in the decomposer 82 and thermally decomposed into sulfur dioxide and oxygen. The produced sulfur dioxide and oxygen are separated and removed by unseparated sulfuric acid by the separator 13 and then sent to the reactor 10 to be subjected to a thermochemical reaction. The undecomposed sulfuric acid is returned to the sulfuric acid concentrator 12 through the return line L28, and again concentrated, evaporated and decomposed in the sulfuric acid evaporation / decomposition unit 8.

  By the way, when only the hydrogen production facility 1 is stopped while the reactor is in operation for the inspection or repair of the hydrogen production facility, the secondary reaction is first performed to stop the decomposition reaction of sulfuric acid. By bypassing the supply of the secondary system He to the sulfuric acid evaporative decomposition unit 8 using the system He bypass line L13, the temperature of the sulfuric acid evaporative decomposition unit 8 is lowered. At this time, the secondary heat removal by the sulfuric acid evaporation / decomposition is replaced by the secondary pressurized water cooler 6. The secondary system He exiting the secondary pressurized water cooler 6 is guided to the hydrogen iodide decomposition unit 9 and maintains the temperature of the hydrogen iodide decomposition unit 9 at 114 ° C. or higher, which is the iodine precipitation temperature. As a result, there is no possibility that iodine is deposited, and the pump, valve, and piping are not blocked. At the same time, in the secondary pressurized water cooler 6, high-temperature water is generated by heat exchange with the secondary system He.

  When the operating pressure of the hydrogen production facility 1 is 20 atm, saturated water at about 220 ° C. is obtained by setting the pressure on the water side of the secondary pressurized water cooler 6 as a heat exchanger to 20 atm. This high-temperature water is introduced into the hydrogen iodide decomposition unit 9 using the high-temperature water introduction pipe L14, and equipment such as pipes, valves and pumps connected to each part of the hydrogen iodide decomposition unit 9 is washed to remove iodine. To do. The fluid after washing is led from the reactor 10 through the piping of the discharge line L15 to the waste treatment facility 16 to be rendered harmless or to be regenerated.

  After completion of the cleaning of the piping of the hydrogen iodide decomposition unit 9, the secondary system He bypass line L 13 is closed, the secondary system He is removed through the secondary pressurized water cooler 6, and then returned to the intermediate heat exchanger 4. Return the hydrogen production facility 1 to room temperature.

  According to the present embodiment, before the hydrogen production facility is stopped and returned to room temperature, it is washed with water having a temperature higher than the precipitation temperature of iodine, so that precipitation of iodine when the temperature is returned to room temperature can be prevented. . Further, since the high-temperature water for cleaning is generated using the heat of the secondary system He bypassing the sulfuric acid evaporative decomposition unit 8, no special heat source is required for generating the high-temperature water. Furthermore, the hydrogen iodide decomposition unit 9 is maintained at a temperature higher than the iodine precipitation temperature by the secondary system He during the preparation and cleaning of the high-temperature water for washing, so that the precipitation of iodine during the plant shutdown is effective. Can be prevented.

(Second Embodiment)
Next, the equipment of the second embodiment will be described with reference to FIG. Note that the description of the same parts as the above embodiments will be omitted.
In the hydrogen production facility 1A of the second embodiment, the secondary pressurized water cooler 6 is divided and the two-stage coolers 61 and 62 are installed. The secondary system He exiting from the first-stage secondary pressurized water cooler 61 is guided to the second-stage secondary pressurized water cooler 62, and the secondary system He exiting from the secondary pressurized water cooler 62 is intermediated by switching the valve. It returns to the heat exchanger 4 or is led to the heat exchange units HE6 and HE7 of the hydrogen iodide decomposition unit 9 through the secondary system He bypass line L13.

  The pressurized water circulation system and the heat radiating part of the secondary pressurized water coolers 61 and 62 are independent of each other, and a high temperature water introduction pipe L14 is connected to the pressurized water outlet pipe L64 of the first-stage secondary pressurized water cooler 61. The heat removal capacity of the secondary pressurized water cooler 61 corresponds to the amount of heat consumed in the sulfuric acid evaporative decomposition unit 8 during normal operation, and the first-stage secondary pressurized water cooler 61 and the second-stage secondary pressurized water cooler 62 The combined heat removal capacity corresponds to the amount of heat consumed in the hydrogen production facility during normal operation.

  In such a hydrogen production facility 1A, if the nuclear reactor and the hydrogen production facility are in normal operation, the hydrogen production facility 1A is maintained at a temperature suitable for the reaction as in the case of the facility of the first embodiment. On the other hand, when only the hydrogen production facility is shut down while the reactor is in operation for inspection or repair of the hydrogen production facility, the secondary system is first stopped to stop the decomposition reaction of sulfuric acid. The supply of the secondary system He of the sulfuric acid evaporative decomposition unit 8 is bypassed using the He bypass line L13, and the temperature of the sulfuric acid evaporative decomposition unit 8 is lowered. At this time, the heat removal of the secondary system He by sulfuric acid evaporative decomposition is substituted by using the first-stage secondary pressurized water cooler 61. The high-pressure water is circulated to the first-stage secondary pressurized water cooler 61, and the high-pressure water circulation of the second-stage secondary pressurized water cooler 62 is stopped. In this way, heat removal by bypassing the sulfuric acid evaporation line can be supplemented by the first-stage secondary pressurized water cooler 61, and at the same time, high-temperature water is generated to clean the hydrogen iodide decomposition unit 9.

  The secondary system He exiting the secondary pressurized water cooler 61 is guided to the hydrogen iodide decomposition unit 9 and keeps the temperature of the hydrogen iodide decomposition unit 9 at 114 ° C., which is the precipitation temperature of iodine, so that iodine may precipitate. This eliminates the blockage of pumps, valves, and piping. After the cleaning of the hydrogen iodide decomposition unit 9 is completed, when the cleaning of the hydrogen iodide decomposition line is completed, the secondary He bypass line L13 is closed and the supply of high-pressure water to the second-stage secondary pressurized water cooler 62 is started. Then, after removing heat from the secondary system He, it is returned to the intermediate heat exchanger.

  According to the present embodiment, by installing a plurality of secondary pressurized water coolers (61 and 62) according to the amount of heat removal, temperature management according to the operation mode of the hydrogen production facility can be performed. In this embodiment, a two-stage secondary pressurized water cooler is provided to generate high-temperature water. However, the present invention is not limited to this, and the third, fourth, fifth, and sixth stages. Or you may make it provide a multistage secondary cooling water cooler more than that, and produce | generate high temperature water.

(Third embodiment)
Next, the equipment of the third embodiment will be described with reference to FIG. In addition, description of the part which this embodiment overlaps with the installation of said embodiment is abbreviate | omitted.
The equipment 1B of the third embodiment supplies a high-temperature water supply line L17 connected to the upstream line L22 (hydrogen iodide transport line) of the hydrogen iodide decomposition unit 9, and supplies high-temperature water to the high-temperature water supply line L17. And a heating device 18 for adding to the equipment of the second embodiment described above. Any device can be used as the heating device 18 as long as a necessary amount of heat can be secured. For example, the auxiliary cooler 7 is used. A flow rate adjustment valve V7 is attached to the high temperature water supply line L17 so that the flow rate of the high temperature water is adjusted to a desired flow rate.

  In such a hydrogen production facility 1B, when the supply of heat to the hydrogen production facility is suddenly stopped for some reason, high-temperature water can be immediately created using the heating device 18, and the hydrogen iodide decomposition unit can be formed using this high-temperature water. Since 9 can be washed, precipitation of iodine in each part of the hydrogen production facility is effectively prevented. When the heat source is a HTGR, in the event that the circulation of the primary system He to the intermediate heat exchanger 4 is stopped and heat is not transferred to the secondary system He, the auxiliary cooler 7 is activated. The primary system He is removed using pressurized water, and the decay heat of the reactor is removed. Therefore, when the heat source is a high temperature gas furnace, the auxiliary cooler 7 can be used as the heating device 18. When the heat source is equipment other than the nuclear reactor such as incineration equipment, a boiler is attached and used as the heating device 18.

(Fourth embodiment)
Next, the equipment of the fourth embodiment will be described with reference to FIG. In addition, description of the part which this embodiment overlaps with the installation of said embodiment is abbreviate | omitted.
The equipment 1C of the fourth embodiment includes a solvent supply line L19 connected to the upstream line L22 (hydrogen iodide transport line) of the hydrogen iodide decomposition unit 9, and a solvent for supplying the solvent to the solvent supply line L19. The tank 20 is added to the above-described second embodiment. A supply pump P3 and a flow rate distribution adjusting valve V8 are attached to the solvent supply line L19.

  In such a hydrogen production facility 1C, when heat supply to the hydrogen production facility suddenly stops for some reason, the solvent is injected from the solvent tank 20 into the upstream line L22 of the hydrogen iodide decomposition unit 9 via the line L19. Therefore, it is possible to effectively prevent iodine from being deposited on the hydrogen production facility. As the solvent, an organic solvent having high iodine solubility such as ethanol is used. According to the present embodiment, even when the supply of heat from the heat source is stopped, the hydrogen iodide decomposition line can be cleaned without using a heating device to suppress iodine precipitation.

  In the present invention, in a facility for producing hydrogen using the thermochemical method (IS method), the facility is returned to room temperature without causing precipitation of iodine when the supply of heat from the heat source is stopped and when the operation of the hydrogen production facility is stopped. It can be used for a thermochemical hydrogen production facility capable of

The schematic block diagram which shows the cooling system of the high temperature gas furnace to which this invention is applied. The block diagram which shows the thermochemical hydrogen production equipment which concerns on the 1st Embodiment of this invention. The material balance figure which shows the flow of the substance in the installation of 1st Embodiment. The block diagram which shows the thermochemical hydrogen production equipment which concerns on the 2nd Embodiment of this invention. The block diagram which shows the thermochemical hydrogen production equipment which concerns on the 3rd Embodiment of this invention. The block diagram which shows the thermochemical hydrogen production equipment which concerns on the 4th Embodiment of this invention.

Explanation of symbols

1, 1A, 1B, 1C ... thermochemical hydrogen production facility,
2 ... HTGR (heat source), 4 ... intermediate heat exchanger, 5 ... primary pressurized water cooler,
6, 61, 62 ... secondary pressurized water cooler (heat exchanger of the third piping system),
7 ... Auxiliary cooler, 8 ... Sulfuric acid evaporative decomposition part, 9 ... Hydrogen iodide decomposition part,
10 ... reactor, 11 ... two-phase separator, 12 ... sulfuric acid concentrator, 13, 94 ... separator,
14 ... High temperature water introduction piping, 15 ... Discharge piping, 16 ... Waste treatment equipment,
17 ... High temperature water supply pipe, 18 ... Heating device, 19 ... Solvent supply pipe, 20 ... Solvent tank,
HE1 to HE3 ... heat exchanger, HE4 to HE9 ... heat exchange section,
L2-L5 ... Primary He line (first piping system),
L6, L7 ... Secondary He line (second piping system),
L8 ... secondary heat exchange line (heat exchange pipe branched from the second pipe system),
L13 ... Secondary He bypass line,
L14, L61, L62 ... high temperature water introduction line (third piping system),
L15 ... Waste discharge line (discharge pipe),
L22 ... Hydrogen iodide transport line,
L23 to L25 ... sulfuric acid decomposition line,
L26 ... Heat exchange line for sulfuric acid decomposition products,
L27 ... Separate take-out line,
L31 to L34 ... Unreacted substance return line,
L35 ... Reaction product take-out line,
V1 to V8: flow distribution adjusting valve (connecting portion), P1, P2: circulation pump, P3: supply pump.

Claims (9)

Heat source 2;
First piping systems L2 to L5 that transport a first fluid that exchanges heat with the heat source 2;
Second piping systems L6, L7 for transporting the second fluid;
An intermediate heat exchanger 4 connected to the first piping system L3 and the second piping system L7, respectively, for exchanging heat between the first fluid and the second fluid;
A sulfuric acid evaporative decomposition unit 8 for evaporating and decomposing sulfuric acid by exchanging heat with the second fluid;
A hydrogen iodide decomposition section 9 for separating and decomposing hydrogen iodide by exchanging heat with the second fluid;
A reactor 10 connected to the sulfuric acid evaporative decomposition unit 8 and the hydrogen iodide decomposition unit 9 via a separator, respectively, and reacting sulfur dioxide, iodine and water to produce sulfuric acid and hydrogen iodide;
The second piping system L6, L7 branches from the second piping system L6, L7 upstream of the portion in contact with the sulfuric acid evaporative decomposition unit 8, and the sulfuric acid evaporative decomposition unit 8 and the hydrogen iodide decomposition unit Heat exchange pipe L8 for exchanging heat with 9, respectively;
Third piping systems L61 and L62 for transporting the third fluid;
A heat exchanger 6 connected to the heat exchange pipe L8 via the second pipe systems L6, L7, and applying heat of the second fluid to the third fluid;
Provided where the heat exchange pipe L8 branches from the second pipe systems L6, L7, the flow rate of the second fluid to the heat exchanger 6 and the second flow to the second pipe system. A first valve V1 for adjusting the distribution of the fluid flow rate;
The third fluid is introduced into the hydrogen iodide transport pipe L22 that branches from the third pipe system L62 on the outlet side of the heat exchanger 6 of the third pipe system and goes to the hydrogen iodide decomposition section 9. A third fluid introduction pipe L14,
A second valve V2 that is provided where the third fluid introduction pipe L14 branches from the third pipe system L62, and adjusts the flow rate of the third fluid;
The third fluid introduction pipe L14 is provided at a place where it is connected to the hydrogen iodide transport pipe L22, and a connection portion V3 for joining the third fluid to hydrogen iodide flowing in the hydrogen iodide transport pipe L22. When,
A waste treatment facility 16 connected to the reactor 10 via a discharge pipe L15 for discharging waste;
The heat exchange pipe L8 is connected to the downstream side of the part in contact with the sulfuric acid evaporative decomposition part 8, and the heat exchange pipe L8 is connected to the upstream side of the part in contact with the hydrogen iodide decomposition part 9, and the second A bypass pipe L13 for bypassing the fluid to the hydrogen iodide decomposition unit 9 without exchanging heat with the sulfuric acid evaporation decomposition unit 8,
The bypass pipe L13 is provided where the second pipe system L6 branches, and the flow rate of the second fluid to the bypass pipe L13 and the flow rate of the second fluid to the second pipe system A fourth valve V4 for adjusting the distribution of
A fifth valve V5 that is provided where the bypass pipe L13 merges with the heat exchange pipe L8 and adjusts a flow rate distribution flowing from the bypass pipe L13 into the heat exchange pipe L8. Thermochemical hydrogen production facility. The heat exchanger 6 includes a plurality of heat exchangers 61 and 62,
2. The hydrogen production facility according to claim 1, comprising a plurality of second piping systems L <b> 63 to L <b> 65 for connecting the plurality of heat exchangers 61 and 62. The heat exchanger 6 includes a plurality of heat exchangers 61 and 62,
The said 3rd fluid introduction piping L14 has branched from the said 3rd piping system L64 of the said heat exchanger 61 nearest to the said 1st valve V1, Either of Claim 1 or 2 characterized by the above-mentioned. The hydrogen production facility according to item 1. Furthermore, a fourth piping system L17 for introducing a fourth fluid between the hydrogen iodide decomposition unit 9 and the reactor 10,
A heating device 18 for heating the fourth fluid flowing in the fourth piping system L17;
A valve V7 for adjusting the flow rate of the fourth fluid introduced from the fourth piping system L17 to the hydrogen iodide decomposition unit 9;
The hydrogen production facility according to claim 1, comprising: Furthermore, a fourth piping system L19 for introducing a fourth fluid between the hydrogen iodide decomposition unit 9 and the reactor 10,
A solvent tank 20 connected to the fourth piping system L19 and containing the fourth fluid;
A pump P3 which is provided in the fourth piping system L19 and adjusts the flow rate of the fourth fluid introduced into the hydrogen iodide decomposition 9;
The hydrogen production facility according to claim 1, comprising: The hydrogen production facility according to claim 1, wherein the third fluid is water or steam. The hydrogen production facility according to claim 4, wherein the fourth fluid is water or steam. The hydrogen production facility according to claim 5, wherein the fourth fluid is ethanol. The heat source (2) is a high-temperature gas furnace, the heating device (18) is a primary pressurized water cooler (5) of the high-temperature gas furnace, and the third fluid is pressurized water of the primary pressurized water cooler (5). 4. The hydrogen production facility according to 4.

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