Cooling method for electrolytic module and electrolysis system

Abstract

To provide a cooling method for an electrolytic module and an electrolysis system capable of lowering the ambient temperature inside the container.SOLUTION: A cooling method for an electrolytic module 200 that cools the electrolytic module 200 comprising at least one electrolytic cartridge 220 that comprises an electrolysis cell and generates hydrogen by electrolyzing water vapor generated from feed water, a pressure vessel 210 housing the electrolytic cartridge 220, heat-exchanges air with the feed water to heat the feed water, and supplies the heat-exchanged air to the pressure vessel 210 to cool the interior of the pressure vessel 210.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cooling method for an electrolysis module and an electrolysis system. [Background technology]

[0002] For example, Patent Document 1 discloses a steam electrolysis system that generates hydrogen by steam electrolysis. The system disclosed in Patent Document 1 includes a module having a solid oxide electrolysis cell (SOEC). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7282968 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-133305 Summary of the Invention [Problem to be solved by the invention]

[0004] In a steam electrolysis system, the atmospheric temperature inside the pressure vessel is, for example, about 400° C. to 450° C. This requires the use of highly heat-resistant materials, such as stainless steel instead of carbon steel for structural members housed inside the vessel, and nickel instead of copper-based materials for current-carrying members, which increases the equipment costs. Therefore, in order to reduce the unit cost of hydrogen production, it is necessary to reduce equipment costs, and we are considering reducing the atmospheric temperature inside the pressure vessel in order to reduce equipment costs by using relatively inexpensive materials that do not have high heat resistance as materials for the structural components housed inside the pressure vessel.

[0005] On the other hand, it is desirable to increase the pressure (for example, about 3 MPa to 5 MPa) of the entire steam electrolysis system in terms of efficiency. However, it is estimated that increasing the pressure in the system will increase the ambient temperature inside the pressure vessel, and as a countermeasure, it is necessary to reduce the ambient temperature. The reason why it is desirable to increase the pressure of a steam electrolysis system is as follows: the hydrogen produced is often ultimately used at high pressure, and the power required to pressurize the raw material water is less than the power required to pressurize the produced hydrogen.

[0006] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide an electrolysis module cooling method and an electrolysis system that can reduce the atmospheric temperature inside a container. [Means for solving the problem]

[0007] In order to solve the above problems, the electrolysis module cooling method and electrolysis system of the present disclosure employ the following measures. A cooling method for an electrolysis module according to one aspect of the present disclosure is a method for cooling an electrolysis module, the method comprising: an electrolysis cell having a hydrogen electrode, an oxygen electrode, and an electrolyte layer disposed between the hydrogen electrode and the oxygen electrode; at least one electrolysis cartridge that generates hydrogen by electrolyzing water vapor generated from feed water; and a container that houses the electrolysis cartridge; the method comprises: exchanging heat between a heat transfer gas and the feed water to heat the feed water; and supplying the heat-exchanged heat transfer gas to the container to cool the inside of the container.

[0008] An electrolysis system according to an aspect of the present disclosure includes an electrolysis module, a heat exchanger, and a heat transfer gas supply line. The electrolysis module has at least one electrolysis cartridge and a container. The electrolysis cartridge includes an electrolysis cell having a hydrogen electrode, an oxygen electrode, and an electrolyte layer disposed between the hydrogen electrode and the oxygen electrode. Hydrogen is produced by electrolyzing water vapor generated from feedwater. The container accommodates the electrolysis cartridge. The heat transfer gas supply line is a line through which a heat transfer gas flows. The heat transfer gas is supplied to the heat exchanger as a heat source for heating the feedwater, and the heat transfer gas that has been heat exchanged in the heat exchanger is supplied to the container. [Effects of the Invention]

[0009] According to the present disclosure, the ambient temperature inside the container can be reduced. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic configuration diagram of a steam electrolysis system according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a configuration diagram of an electrolysis module included in the steam electrolysis system shown in FIG. 1. [Figure 3] FIG. 2 is a side view of an electrolytic cartridge included in the electrolytic module. [Figure 4] FIG. 4 is a front view of the electrolytic cartridge shown in FIG. 3. [Figure 5] FIG. 5 is a schematic diagram showing the structure of the electrolytic cartridge shown in FIG. [Figure 6] FIG. 6 is a partially enlarged cross-sectional view of the cell stack in the vicinity of the electrolysis cell shown in FIG. 5. [Figure 7] FIG. 3 is a schematic diagram of an electrolysis cartridge provided in the electrolysis module shown in FIG. 2. [Figure 8] FIG. 2 is a configuration diagram of an electrolysis module included in the steam electrolysis system shown in FIG. 1 (another embodiment 1). [Figure 9] FIG. 2 is a configuration diagram of an electrolysis module included in the steam electrolysis system shown in FIG. 1 (another embodiment 2). [Figure 10] FIG. 10 is a schematic configuration diagram of a steam electrolysis system according to a second embodiment of the present disclosure. [Figure 11] FIG. 10 is a schematic configuration diagram of a steam electrolysis system according to a third embodiment of the present disclosure. [Figure 12] FIG. 11 is a configuration diagram of an electrolysis module included in the steam electrolysis system shown in FIG. 10. [Figure 13] FIG. 10 is a schematic configuration diagram of a steam electrolysis system according to a fourth embodiment of the present disclosure. [Figure 14] FIG. 10 is a schematic configuration diagram of a steam electrolysis system according to a fifth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, electrolysis module cooling methods and electrolysis systems according to first to fifth embodiments of the present disclosure will be described with reference to the drawings. The terms "height direction," "depth direction," and "width direction" are used for the purpose of explanation and do not limit the actual orientation of the electrolysis module and the steam electrolysis system. Furthermore, the "height direction," "depth direction," and "width direction" are perpendicular to one another.

[0012] [First embodiment] <System Overview> A steam electrolysis system 10, which is an example of an electrolysis system, is a system that produces hydrogen by heating feedwater to generate steam and electrolyzing the steam under high temperature and high pressure. As shown in FIG. 1, the steam electrolysis system 10 includes an electrolysis module 200, multiple heat exchangers L11, L41, and L51, a compression device 120, a water supply device 130, a power supply device 140, and lines (piping systems) connecting the devices / equipment to one another.

[0013] The electrolysis module 200 is a device that performs steam electrolysis. Although details will be described later, the electrolysis module 200 is generally a device that electrolyzes supplied water vapor under high temperature and high pressure.

[0014] Each of the heat exchangers L11, L41, and L51 is a device for heating feedwater and / or for heating feedwater to generate steam that is supplied to the electrolysis module 200.

[0015] The compression device 120 is a device that compresses the heat transfer gas supplied to the electrolysis module 200. The heat transfer gas may be, for example, an oxidizing gas such as air. In the following description, the heat transfer gas is assumed to be air. The compression device 120 includes a compressor 121 , a turbine 122 , and an electric motor 123 . The compressor 121 and the turbine 122 are connected to one another by the same rotating shaft, and the compressor 121 is driven by the rotation of the turbine 122. The electric motor 123 is configured to drive the compressor 121 or to assist in driving the compressor 121 when the output of the turbine 122 is low (for example, during start-up of the steam electrolysis system 10).

[0016] The water supply device 130 is a device that stores and delivers water (supply water). This supply water is heated in the heat exchangers L11, L41, and L51 to become steam. The power supply device 140 is a device that supplies the electrolysis module 200 with the electric power used in steam electrolysis.

[0017] The compressor 121 of the compression device 120 is connected to the electrolysis module 200 via an air supply primary line L10. That is, the air supply primary line L10 connects the compressor 121 and the electrolysis module 200. High-temperature, high-pressure air compressed by the compressor 121 is supplied to the electrolysis module 200 via the air supply primary line L10. The primary air supply line L10 is provided with a heat exchanger L11. The heat exchanger L11 serves as a heat source for heating the feedwater. Therefore, the air supplied to the electrolysis module 200 has undergone heat exchange with the feedwater, and its temperature is lower than the temperature before the heat exchange (e.g., about 300°C to 400°C), e.g., about 200°C to 300°C.

[0018] The turbine 122 of the compressor 120 is connected to the electrolysis module 200 via an oxygen-enriched air discharge line L50. That is, the oxygen-enriched air discharge line L50 connects the turbine 122 to the electrolysis module 200. The high-temperature, high-pressure oxygen-enriched air discharged from the electrolysis module 200 is guided via the oxygen-enriched air discharge line L50 to the turbine 122, and drives the turbine 122 to rotate. The oxygen-enriched air discharge line L50 is provided with a heat exchanger L51, which serves as a heat source for heating the feedwater.

[0019] A hydrogen discharge line L40 is connected to the electrolysis module 200. High-temperature, high-pressure hydrogen generated and discharged from the electrolysis module 200 and a portion of the water vapor (water vapor remaining without being electrolyzed) are supplied to the outside of the electrolysis module 200 (for example, to a facility for storing hydrogen) via the hydrogen discharge line L40. The hydrogen discharge line L40 is provided with a heat exchanger L41, which serves as a heat source for heating the feedwater.

[0020] The water supply device 130 is connected to the electrolysis module 200 via a water / steam supply line L30. That is, the water / steam supply line L30 connects the water supply device 130 and the electrolysis module 200. The water / steam supply line L30 is provided with, for example, heat exchangers L11, L51, and L41 in parallel. The feedwater flowing through the water / steam supply line L30 is heated and converted into steam as it passes through the heat exchangers L11, L41, and L51. That is, the feedwater delivered from the water supply device 130 is heated and converted into steam in the heat exchangers L11, L41, and L51, and the generated high-temperature steam is supplied to the electrolysis module 200. As described above, the heat sources for heating the feedwater are the air flowing through the heat exchanger L11, the oxygen-enriched air flowing through the heat exchanger L51, and the hydrogen flowing through the heat exchanger L41. Note that other heat exchangers (through which a fluid for heating the feedwater flows) than the heat exchangers L11, L51, and L41 may be further provided in the water / steam supply line L30. Furthermore, each heat exchanger may be provided in series in the water / steam supply line L30. Furthermore, only some of the heat exchangers may be provided in parallel in the water / steam supply line L30, and the remaining heat exchangers may be provided in series.

[0021] <Details of the electrolysis module> As shown in FIG. 2, the electrolysis module 200 includes a pressure vessel 210, a plurality of electrolysis cartridges 220, a submodule heat insulating material 240, a main supply pipe 251, and a main discharge pipe 252.

[0022] The pressure vessel 210 is a metal vessel having an internal space. The inner surface of the pressure vessel 210 may be provided with a heat insulating material (heat retaining material). The pressure vessel 210 contains a sub-module including a plurality of electrolytic cartridges 220 and a sub-module heat insulating material 240 disposed around the electrolytic cartridges 220 .

[0023] The detailed configuration of the electrolytic cartridge 220 will be described with reference to FIGS. Fig. 3 is a side view of the electrolytic cartridge 220. Fig. 4 is a front view of the electrolytic cartridge 220 shown in Fig. 3. Fig. 5 is a schematic diagram of the electrolytic cartridge shown in Fig. 4. Fig. 6 is a partially enlarged cross-sectional view of the cell stack 230 near the electrolytic cell 232 shown in Fig. 5.

[0024] As shown in Figures 3, 4 and 5, the electrolysis cartridge 220 includes a plurality of cell stacks 230, a water vapor supply header 221a, a hydrogen discharge header 221c, an air supply header 222a, an oxygen-enriched air discharge header 222c, and a cartridge insulator 223.

[0025] As shown in FIG. 6, each cell stack 230 is a cylindrical component extending in the height direction, and includes a substrate tube 231, a solid oxide electrolysis cell 232 (hereinafter simply referred to as "electrolysis cell 232"), an interconnector 233, and a lead film 234. The substrate tube 231 is a cylindrical tube extending in the axial direction, and is made of a porous material. On the outer peripheral surface of the substrate tube 231, a plurality of electrolytic cells 232 and interconnectors 233 formed between adjacent electrolytic cells 232 are formed. The electrolysis cell 232 has a hydrogen electrode 232a as a cathode, an oxygen electrode 232b as an anode, and an electrolyte layer 232c provided between the hydrogen electrode 232a and the oxygen electrode 232b. Of the multiple electrolytic cells 232 formed on the outer peripheral surface of the substrate tube 231, a lead film 234 is provided electrically connected via an interconnector 233 to the oxygen electrode 232b of the electrolytic cell 232 formed at the end in the axial direction of the substrate tube 231, and a lead film 234 is provided electrically connected to the hydrogen electrode 232a of the electrolytic cell 232 formed at the other end of the outermost end. The lead film 234 supplies DC power to the plurality of electrolytic cells 232 connected in series via the interconnectors 233 .

[0026] When external power is supplied between the hydrogen electrode 232a and the oxygen electrode 232b via the lead film 234, some of the high-temperature water vapor supplied to the hydrogen electrode 232a receives electrons and is separated into hydrogen and oxygen ions, generating hydrogen. The separated oxygen ions move inside the electrolyte layer 232c to the oxygen electrode 232b, where they release electrons and generate oxygen.

[0027] The multiple cell stacks 230 configured as described above are arranged at intervals in the depth and width directions, for example, with the axial direction coinciding with the height direction, as shown in Figures 3, 4 and 5.

[0028] A steam supply header 221a is provided above the plurality of cell stacks 230, and a hydrogen discharge header 221c is provided below the plurality of cell stacks 230. The space defined by the water vapor supply header 221a communicates with the space inside each cell stack 230 (the space inside the substrate tube 231) at the upper end of the cell stack 230. In addition, the space defined by the hydrogen discharge header 221c communicates with the space inside each cell stack 230 at the lower end of the cell stack 230. In other words, the space defined by the water vapor supply header 221a and the space defined by the hydrogen discharge header 221c communicate with each other via the space inside each cell stack 230.

[0029] A water vapor supply pipe 221b, which is connected to the water / water vapor supply line L30, is connected to the water vapor supply header 221a, and the water vapor supply header 221a is configured so that high-temperature water vapor is supplied from the water / water vapor supply line L30. The water vapor introduced to the water vapor supply header 221a flows into a space inside the cell stack 230 and flows toward the hydrogen discharge header 221c. In the process, the water vapor is electrolyzed in the cell stack 230, and high-temperature hydrogen generated by the electrolysis and some of the water vapor that remains unelectrolyzed are introduced to the hydrogen discharge header 221c. A hydrogen discharge pipe 221d, which is connected to the hydrogen discharge line L40, is connected to the hydrogen discharge header 221c, and the hydrogen discharge header 221c is configured so that the generated hydrogen and some of the water vapor are discharged to the hydrogen discharge line L40.

[0030] An air supply header 222a is provided at the bottom of the multiple cell stacks 230 adjacent to the upper surface of the hydrogen discharge header 221c, and an oxygen-enriched air discharge header 222c is provided at the top of the multiple cell stacks 230 adjacent to the lower surface of the water vapor supply header 221a. Neither the space defined by the air supply header 222a nor the space defined by the oxygen-enriched air discharge header 222c is connected to the space inside each cell stack 230 (the space inside the substrate tube 231).

[0031] A cartridge heat insulator 223 is provided between the air supply header 222a and the oxygen-enriched air discharge header 222c, which are spaced apart in the height direction. The cartridge heat insulating material 223 has a cartridge peripheral heat insulating portion 223a, a cartridge upper heat insulating portion 223b, and a cartridge lower heat insulating portion 223c. However, each heat insulating portion may be integrally formed. The cartridge peripheral insulation part 223a is a heat insulating material that covers the periphery of a group or cluster of multiple cell stacks 230. A gap (space) is provided between the cartridge peripheral insulation part 223a and the cell stacks 230. Note that the cartridge peripheral insulation part 223a does not cover the periphery of each individual cell stack 230. The cartridge upper insulation section 223b is an insulating material interposed between the cartridge peripheral insulation section 223a and the oxygen-enriched air discharge header 222c. Each cell stack 230 is inserted into the cartridge upper insulation section 223b. Between the cartridge upper insulation section 223b and each cell stack 230, a discharge flow path 223b1 through which oxygen-enriched air flows is provided. The cartridge lower heat insulating section 223c is a heat insulating material interposed between the cartridge peripheral heat insulating section 223a and the air supply header 222a. Each cell stack 230 is inserted into the cartridge lower heat insulating section 223c. A supply flow path 223c1 through which air flows is provided between the cartridge lower heat insulating section 223c and each cell stack 230.

[0032] The cartridge peripheral insulation section 223a, the cartridge upper insulation section 223b, and the cartridge lower insulation section 223c of the cartridge insulation material 223 define an electrolysis chamber (reaction chamber) 224. All of the electrolysis cells 232 formed on the outer peripheral surface of each cell stack 230 are housed in this reaction chamber 224. Reaction chamber 224 communicates with the space defined by oxygen-enriched air discharge header 222c via discharge flow path 223b1. Reaction chamber 224 also communicates with the space defined by air supply header 222a via supply flow path 223c1. In other words, the space defined by air supply header 222a and the space defined by oxygen-enriched air discharge header 222c communicate with each other via supply flow path 223c1, reaction chamber 224, and discharge flow path 223b1.

[0033] An air supply pipe 222b connected to the air supply primary line L10 is connected to the air supply header 222a, and the air supply header 222a is configured so that air is supplied from the air supply primary line L10. The air introduced into the air supply header 222a flows into the reaction chamber 224 via the supply flow path 223c1 and toward the oxygen-enriched air discharge header 222c. During this process, oxygen produced by steam electrolysis mixes with air supplied from the primary air supply line L10 and is introduced to the oxygen-enriched air discharge header 222c via the discharge flow path 223b1. The mixture of the produced oxygen and the supplied air is called oxygen-enriched air. The oxygen-enriched air discharge header 222c is connected to an oxygen-enriched air discharge pipe 222d which is connected to the oxygen-enriched air discharge line L50, and the oxygen-enriched air discharge header 222c is configured so that the oxygen-enriched air is discharged into the oxygen-enriched air discharge line L50.

[0034] The air and / or oxygen-enriched air flowing through the reaction chamber 224 removes heat from the cell stack 230, which has reached a high temperature (for example, about 700°C to 1000°C) due to the electrolysis reaction, thereby cooling the cell stack 230 and, ultimately, the electrolysis cartridge 220.

[0035] As shown in FIG. 7, in this embodiment, the air supply header 222a and the air supply pipe 222b of the electrolytic cartridge 220 are omitted. In this case, the air supply primary line L10 is not connected to the air supply pipe 222b, and is configured to supply air to the inside of the pressure vessel 210. The air supplied to the inside of the pressure vessel 210 via the air supply primary line L10 is then taken into the reaction chamber 224 via the supply flow path 223c1.

[0036] As shown in FIG. 2, the plurality of electrolytic cartridges 220 are provided with a sub-module heat insulating material (enclosure member) 240 . Hereinafter, the plurality of electrolytic cartridges 220 and the sub-module heat insulating material 240 are defined as a sub-module.

[0037] The submodule insulation 240 has at least one of a submodule peripheral insulation section 241, a submodule upper insulation section 242, and a submodule lower insulation section 243. However, each insulation section may be formed integrally. The outer periphery of the submodule insulation 240 is covered by a frame member (not shown). The submodule peripheral insulation part 241 is an insulating material that covers the periphery of a group of electrolysis cartridges 220. A gap is provided between the submodule peripheral insulation part 241 and the electrolysis cartridges 220. Note that the submodule peripheral insulation part 241 does not cover the periphery of each individual electrolysis cartridge 220. The submodule upper heat insulating section 242 is a heat insulating material that covers the upper part of the group or assembly of multiple electrolysis cartridges 220 . For example, as shown in FIG. 12 (not in the first embodiment), the submodule lower heat insulating section 243 is a heat insulating material that covers the lower part of a group or assembly of a plurality of electrolysis cartridges 220. 2 , the electrolysis module 200 of this embodiment does not include the submodule lower heat insulating part 243. This is because air supplied from the air supply primary line L10 is taken from the outside to the inside (inside) of the submodule heat insulating material 240 and then taken into the reaction chamber 224 via the supply flow path 223c1 provided in the cartridge lower heat insulating part 223c of the electrolysis cartridge 220.

[0038] 2 illustrates an example in which the entire submodule lower insulation 243 is omitted in order to take air from the outside into the inside of the submodule insulation 240 that collectively surrounds the multiple electrolysis cartridges 220. However, at least a structure for taking air from the outside into the inside of the submodule insulation 240 (hereinafter referred to as a "heat medium gas intake section") may be present in any part of the submodule insulation 240. For example, the submodule lower insulation 243 may be partially omitted, or part or all of the submodule peripheral insulation 241 may be omitted, or part or all of the submodule upper insulation 242 may be omitted, or a combination thereof may be used. The frame member that covers the submodule insulation 240 also has a structure for taking in air from the outside to the inside. Naturally, the position of the structure for taking in air that is provided on the frame member corresponds to the position of the heat transfer medium gas intake part of the submodule insulation 240.

[0039] By providing the sub-module heat insulating material 240, heat from the cell stack 230 can be blocked. Although the heat from the cell stack 230 is also blocked by the cartridge insulation 223, if the heat from the cell stack 230, which can reach approximately 700°C to 1000°C, is to be insulated only by the cartridge insulation 223, the cartridge insulation 223 would have to be large. Furthermore, if the cartridge insulation 223 were to be large, the electrolysis cartridge 220 would also have to be large. Therefore, multiple electrolysis cartridges 220, each insulated by the cartridge insulation 223, are collectively covered and insulated by the submodule insulation 240, thereby enabling the heat from the cell stack 230 to be insulated in a stepwise and efficient manner.

[0040] The main supply pipe 251 is a pipe that connects the inside and outside of the pressure vessel 210 . The end of the main supply pipe 251 located outside the pressure vessel 210 is connected to the air supply primary line L10. In addition, the end (exhaust port) of the main supply pipe 251 located inside the pressure vessel 210 is open inside the pressure vessel 210. As a result, air whose temperature has been reduced to approximately 200°C to 300°C in the heat exchanger L11 is supplied into the pressure vessel 210 via the air supply primary line L10. The main supply pipe 251 and the air supply primary line L10 may be configured as an integral unit or as separate units. In either case, the main supply pipe 251 can be considered as part of the air supply primary line L10.

[0041] The air supplied to the inside of the pressure vessel 210 flows inside the pressure vessel 210. At this time, the inside of the pressure vessel 210 functions as a flow path. By the air supplied to the inside of the pressure vessel 210 flowing inside the pressure vessel 210, the atmospheric temperature inside the pressure vessel 210 can be lowered. Thereafter, the air that has cooled the pressure vessel 210 is taken into the submodule heat insulating material 240 via the heat transfer gas intake portion, and then taken into the reaction chamber 224 via the supply flow path 223c1.

[0042] The main discharge pipe 252 is a pipe that connects each oxygen-enriched air discharge pipe 222 d of each electrolysis cartridge 220 to the outside of the pressure vessel 210 . The end of the main discharge pipe 252 located outside the pressure vessel 210 is connected to the oxygen-enriched air discharge line L50. As a result, the oxygen-enriched air discharged from each electrolysis cartridge 220 is supplied to the turbine 122 via the oxygen-enriched air discharge line L50. The main discharge pipe 252 and the oxygen-enriched air discharge line L50 may be configured as an integral unit or as separate units. In either case, the main discharge pipe 252 can be considered to be part of the oxygen-enriched air discharge line L50.

[0043] <About the recirculation line> As shown in FIG. 1, the steam electrolysis system 10 includes a first recirculation line L71 and / or a second recirculation line L72.

[0044] The first recirculation line L71 connects the heat exchanger L41 of the hydrogen discharge line L40 to a portion of the water / steam supply line L30 downstream of the heat exchangers L11, L41, and L51, and is a line that guides the water vapor flowing through the hydrogen discharge line L40 to the water / steam supply line L30.

[0045] The second recirculation line L72 connects the portion of the hydrogen discharge line L40 downstream of the heat exchanger L41 with the portion of the water / steam supply line L30 upstream of the heat exchangers L11, L41, and L51, and is a line that guides the water (condensed water vapor) flowing through the hydrogen discharge line L40 to the water / steam supply line L30. <Flow rate and temperature control> The steam electrolysis system 10 includes a first bypass line L81 and / or a second bypass line L82, and a control unit 160.

[0046] The first bypass line L81 connects the portion of the air supply primary line L10 upstream of the heat exchanger L11 to the portion of the oxygen-enriched air discharge line L50 upstream of the heat exchanger L51, and is a line that guides the air flowing through the air supply primary line L10 to the oxygen-enriched air discharge line L50. The first bypass line L81 is provided with a valve 151. In addition, a flow meter 171 is provided in a portion of the air supply primary line L10 downstream of the point where the first bypass line L81 is connected. The control unit 160 obtains the flow rate of air flowing through the primary air supply line L10 from the flowmeter 171 and controls the aperture of the valve 151 so that an amount of air suitable for cooling is supplied to the electrolysis module 200. For example, to prevent an excessive amount of air from being supplied to the electrolysis module 200, the aperture of the valve 151 can be adjusted to allow some of the air flowing through the primary air supply line L10 to flow into the oxygen-enriched air discharge line L50.

[0047] The second bypass line L82 connects the portion of the air supply primary line L10 upstream of the heat exchanger L11 with the portion of the air supply primary line L10 downstream of the heat exchanger L11, and is a line for mixing high-temperature air before heat exchange in the heat exchanger L11 with low-temperature air after heat exchange. The second bypass line L82 is provided with a valve 152. The electrolysis module 200 is also provided with a thermometer 181. The control unit 160 acquires the temperature inside the pressure vessel 210 from the thermometer 181 and controls the degree of opening of the valve 152 so that the temperature inside the pressure vessel 210 (i.e., the temperature of the air supplied to the electrolysis cartridge 220) is at an appropriate temperature. For example, the control unit 160 can adjust the degree of opening of the valve 151 to increase the temperature of the air (air after heat exchange) flowing through the primary air supply line L10 so that excessively low temperature air is not supplied to the electrolysis cartridge 220.

[0048] <Another Example of Electrolysis Module> In this embodiment, the air supplied to the inside of the pressure vessel 210 via the primary air supply line L10 flows inside the pressure vessel 210, thereby cooling the inside of the pressure vessel 210. In this case, from the viewpoint of efficiently cooling the pressure vessel 210, for example, the heat transfer gas intake portion of the submodule insulation material 240 may be positioned on the opposite side of the electrolytic cartridge 220 from the outlet of the main supply pipe 251 (i.e., the outlet of the primary air supply line L10). An example of this will be described below.

[0049] <<Another Example 1>> 8 , the submodule upper insulation 242 and the submodule lower insulation 243 of the submodule insulation 240 may be omitted, and the submodule insulation 240 may be formed with a submodule peripheral insulation 241, so that air discharged from the outlet of the main supply pipe 251 flows up to the upper part. However, if the submodule lower insulation 243 is omitted, the air discharged from the outlet of the main supply pipe 251 will immediately be taken into the electrolysis cartridge 220. Therefore, by providing the electrolysis module 200 with a blocking member (surrounding member) 261 that collectively blocks the lower parts of the multiple electrolysis cartridges 220, a heat transfer gas intake part is formed so that the air discharged from the outlet of the main supply pipe 251 (air supplied to the lower part of the pressure vessel 210) will reliably flow up to the upper part of the pressure vessel 210. A heat transfer medium gas intake section is formed by using the submodule insulation material 240 and the blocking member 261 as surrounding members for the multiple electrolytic cartridges 220 and providing a surface on one side through which air can easily flow (a surface for taking in the heat transfer medium gas inside). This allows the air discharged from the outlet of the main supply pipe 251 to circulate throughout the pressure vessel 210 before being taken into the heat transfer gas intake section of the submodule insulation 240, resulting in a structure that facilitates cooling of the interior of the pressure vessel 210. Furthermore, because the air flows around the electrolysis cartridge 220 in the height direction inside the submodule insulation 240, a structure that facilitates cooling of the electrolysis cartridge 220 can be achieved.

[0050] <<Another Example 2>> As shown in Figure 9, the main supply pipe 251 may be positioned above the submodule, and the submodule lower insulation section 243 may be omitted from the submodule insulation material 240, so that the submodule insulation material 240 is formed of the submodule upper insulation section 242 and the submodule peripheral insulation section 241, and a heat transfer gas intake section may be formed so that the air discharged from the outlet of the main supply pipe 251 (air supplied to the upper part of the interior of the pressure vessel 210) flows around to the lower part of the interior of the pressure vessel 210. This makes it easier for the air discharged from the outlet of the main supply pipe 251 to circulate throughout the pressure vessel 210 before being taken in by the heat transfer gas intake section of the submodule insulation 240, resulting in a structure that makes it easier for the inside of the pressure vessel 210 to be cooled.

[0051] According to this embodiment, the following effects are achieved. The air whose temperature has been lowered by heat exchange with the feedwater is supplied to the pressure vessel 210, thereby lowering the atmospheric temperature inside the pressure vessel 210. This allows the use of relatively inexpensive materials that do not have high heat resistance as materials for the structural members housed inside the pressure vessel 210 (for example, members constituting the electrolysis cartridge 220), thereby achieving cost reduction. This also serves as a countermeasure against the phenomenon of an increase in the atmospheric temperature inside the pressure vessel 210 caused by increasing the pressure of the entire steam electrolysis system 10 including the electrolysis module 200. Furthermore, since the feed water can be heated by heat exchange with the air, the thermal efficiency of the entire steam electrolysis system 10 can be improved.

[0052] Furthermore, since the air that has been supplied to the pressure vessel 210 and cooled the inside of the pressure vessel 210 is supplied to the electrolysis cartridge 220 without being taken out of the pressure vessel 210, air can be supplied to the electrolysis cartridge 220 with a simple structure.

[0053] Furthermore, by mixing the air that has exchanged heat with the feed water with the air that has not exchanged heat with the feed water, the temperature of the air that has exchanged heat can be adjusted to appropriately control the temperature of the air supplied to the electrolysis module 200, thereby controlling the temperature inside the pressure vessel 210 and the temperature of the air supplied to the electrolysis cartridge 220.

[0054] Furthermore, since the heat transfer gas intake section of the submodule insulation material 240 is located on the opposite side of the electrolytic cartridge 220 from the outlet of the main supply pipe 251 (i.e., the outlet of the primary air supply line L10), the air discharged from the outlet can easily circulate throughout the pressure vessel 210 before being taken in by the heat transfer gas intake section, making it possible to achieve a structure in which the inside of the pressure vessel 210 can be easily cooled.

[0055] [Second embodiment] The steam electrolysis system 10 according to this embodiment differs from the steam electrolysis system 10 according to the first embodiment in that it includes a return line L60, but is otherwise the same. Therefore, the same components as those in the steam electrolysis system 10 according to the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0056] As shown in FIG. 10, the steam electrolysis system 10 includes a return line L60.

[0057] The return line L60 connects the inside of the pressure vessel 210 with the part of the oxygen-enriched air discharge line L50 upstream of the heat exchanger L51, and is a line that guides the air inside the pressure vessel 210 to the oxygen-enriched air discharge line L50. By providing the return line L60, a portion of the air supplied to the interior of the pressure vessel 210 via the primary air supply line L10 can be extracted from the pressure vessel 210, thereby preventing an excessive amount of air from being supplied to the electrolysis cartridge 220 for the operating conditions. In other words, a portion of the air supplied via the primary air supply line L10 can be supplied to the electrolysis cartridge 220, and the remaining air (excess air) can be extracted from the pressure vessel 210.

[0058] The return line L60 is provided with a valve 153. In addition, the return line L60 is provided with a flow meter 172. The control unit 160 may control the opening of the valve 153 so that an appropriate amount of air is supplied to the electrolytic cartridge 220 based on the appropriate amount of air for the operating conditions, the flow rate acquired from the flow meter 171, and the flow rate acquired from the flow meter 172. It is assumed that the appropriate amount of air for the operating conditions is known in advance.

[0059] Instead of the valve 153, a fixed throttle may be provided in the return line L60. In this embodiment, the thermometer 181 used to control the valve 152 provided in the second bypass line L82 is provided in a portion of the air supply primary line L10 downstream of the heat exchanger L11. However, as in the first embodiment, the thermometer 181 may also be provided in the electrolysis module 200.

[0060] According to this embodiment, the following effects are achieved. A portion of the air that is supplied to the pressure vessel 210 and has cooled the interior of the pressure vessel 210 is supplied to the electrolysis cartridge 220, and the remainder of the air that is supplied to the pressure vessel 210 and has cooled the interior of the pressure vessel 210 is extracted from the pressure vessel 210, thereby preventing an excessive amount of air from being supplied to the electrolysis cartridge 220 given the operating conditions.

[0061] [Third embodiment] The steam electrolysis system 10 according to this embodiment differs from the steam electrolysis system 10 according to the first embodiment in the configuration of the electrolysis module 200 and the inclusion of a secondary air supply line L20, but is otherwise the same. Therefore, the same components as those in the steam electrolysis system 10 according to the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0062] As shown in FIG. 11, the steam electrolysis system 10 includes a secondary air supply line (heat medium gas supply line) L20. The secondary air supply line L20 is a line for extracting the air that has been supplied to the inside of the pressure vessel 210 of the electrolysis module 200 via the primary air supply line L10 and has cooled the pressure vessel 210 from the pressure vessel 210, and for supplying the extracted air to the electrolysis cartridge 220.

[0063] 12 , the electrolysis module 200 includes a primary supply main pipe 253, a primary discharge main pipe 254, a secondary supply main pipe 255, and a secondary discharge main pipe 256, instead of the main supply pipe 251 and the main discharge pipe 252 of the first embodiment. In addition, the submodule thermal insulation material 240 is formed of a submodule peripheral insulation section 241, a submodule upper insulation section 242, and a submodule lower insulation section 243. The electrolytic cartridge 220 also has an air supply header 222a and an air supply pipe 222b (see FIG. 5).

[0064] The primary supply main 253 is a pipe that connects the inside and outside of the pressure vessel 210 . An end of the primary supply main pipe 253 located outside the pressure vessel 210 is connected to the air supply primary line L10. In addition, an end (exhaust port) of the primary supply main pipe 253 located inside the pressure vessel 210 is open inside the pressure vessel 210. As a result, air whose temperature has been reduced to approximately 200°C to 300°C in the heat exchanger L11 is supplied into the pressure vessel 210 via the air supply primary line L10. The primary supply main pipe 253 and the air supply primary line L10 may be configured as an integral unit or as separate units. In either case, the primary supply main pipe 253 can be considered as part of the air supply primary line L10.

[0065] The primary discharge main pipe 254 is a pipe that communicates between the inside and outside of the pressure vessel 210 . The end of the primary discharge main pipe 254 located outside the pressure vessel 210 is connected to one end of the air supply secondary line L20. In addition, the end of the primary discharge main pipe 254 located inside the pressure vessel 210 is open inside the pressure vessel 210. As a result, the air that is supplied into the pressure vessel 210 and has cooled the pressure vessel 210 is led to the air supply secondary line L20. That is, air supplied from the primary air supply line L10 to the inside of the pressure vessel 210 via the primary supply main pipe 253 flows inside the pressure vessel 210 and is discharged to the secondary air supply line L20 via the primary discharge main pipe 254. At this time, the inside of the pressure vessel 210 functions as a flow path. The primary discharge main pipe 254 and the air supply secondary line L20 may be configured as an integral unit or as separate units. In either case, the primary discharge main pipe 254 can be considered as part of the air supply secondary line L20.

[0066] The secondary supply main pipe 255 is a pipe that connects each air supply pipe 222 b of each electrolytic cartridge 220 to the outside of the pressure vessel 210 . The end of the secondary supply main pipe 255 located outside the pressure vessel 210 is connected to the other end of the air supply secondary line L20. As a result, the air flowing through the air supply secondary line L20 (air that has cooled the pressure vessel 210) is supplied to the electrolysis cartridge 220.

[0067] The secondary main discharge pipe 256 is a pipe that connects each oxygen-enriched air discharge pipe 222 d of each electrolysis cartridge 220 to the outside of the pressure vessel 210 . The end of the secondary main discharge pipe 256 located outside the pressure vessel 210 is connected to the oxygen-enriched air discharge line L50. As a result, the oxygen-enriched air discharged from each electrolysis cartridge 220 is supplied to the turbine 122 via the oxygen-enriched air discharge line L50.

[0068] As described above, in the steam electrolysis system 10 of this embodiment, the secondary air supply line L20 is used to extract air that has cooled the pressure vessel 210 from the pressure vessel 210, and the extracted air is supplied to the electrolysis cartridge 220.

[0069] As shown in FIG. 11, a flow meter 173 and a pressure applying means 191 are provided in the secondary air supply line L20. The control unit 160 obtains the flow rate of air flowing through the secondary air supply line L20 from the flow meter 173, and controls the pressure applying means 191 so that an appropriate amount of air for the operating conditions is supplied to the electrolysis module 200. Examples of the pressure applying means 191 include a compressor and a pump.

[0070] In this embodiment, the thermometer 181 used to control the valve 152 provided in the second bypass line L82 is provided in a portion of the air supply primary line L10 downstream of the heat exchanger L11. However, similar to the first embodiment, the thermometer 181 may also be provided in the electrolysis module 200.

[0071] According to this embodiment, the following effects are achieved. The air that has been supplied to the pressure vessel 210 and cooled the inside of the pressure vessel 210 is extracted from the pressure vessel 210, the flow rate of the extracted air is adjusted by the pressure applying means 191, and the flow rate-adjusted air is supplied to the electrolytic cartridge 220, so that air at an appropriate flow rate can be supplied to the electrolytic cartridge 220.

[0072] [Fourth embodiment] The steam electrolysis system 10 according to this embodiment is the same as the steam electrolysis system 10 according to the third embodiment except for the configuration of the secondary air supply line L20. Therefore, the same components as those in the steam electrolysis system 10 according to the third embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0073] As shown in FIG. 13, a heat exchanger L21 is provided in the air supply secondary line L20. The heat exchanger L21 is used as a heat source for heating the feedwater. That is, the air extracted from the pressure vessel 210 after cooling the pressure vessel 210 is cooled again in the heat exchanger L21 before being supplied to the electrolysis cartridge 220. The heat exchanger L21 is provided in parallel with the other heat exchangers L11, L41, and L51 on the water / steam supply line L30. However, the heat exchangers may be provided in series on the water / steam supply line L30. Alternatively, only some of the heat exchangers may be provided in parallel on the water / steam supply line L30, with the remaining heat exchangers provided in series.

[0074] The steam electrolysis system 10 includes a third bypass line L83. The third bypass line L83 connects the part of the air supply secondary line L20 upstream of the heat exchanger L21 with the part of the air supply secondary line L20 downstream of the heat exchanger L21, and is a line for mixing high-temperature air before heat exchange in the heat exchanger L21 with low-temperature air after heat exchange. The third bypass line L83 is provided with a valve 154. Furthermore, a thermometer 182 is provided in a portion of the air supply secondary line L20 downstream of the heat exchanger L21. The control unit 160 obtains the temperature of the air flowing through the secondary air supply line L20 from the thermometer 182 and controls the aperture of the valve 154 so that the temperature of the air supplied to the electrolysis cartridge 220 is an appropriate temperature. For example, the aperture of the valve 154 can be adjusted to increase the temperature of the air flowing through the secondary air supply line L20 (air after heat exchange) so that excessively low temperature air is not supplied to the electrolysis cartridge 220.

[0075] In this embodiment, a thermometer 181 used to control the valve 152 provided in the second bypass line L82 is provided in a portion of the air supply primary line L10 downstream of the heat exchanger L11. However, similar to the first embodiment, the thermometer 181 may be provided in the electrolysis module 200.

[0076] According to this embodiment, the following effects are achieved. The air that has been supplied to the pressure vessel 210 and cooled the inside of the pressure vessel 210 is removed from the pressure vessel 210, the air removed from the pressure vessel 210 is again subjected to heat exchange with the feed water, and the air that has been heat exchanged again is supplied to the electrolysis cartridge 220.Therefore, the temperature of the air that has been raised by heat exchange with the pressure vessel 210 can be lowered by heat exchange with the feed water before being supplied to the electrolysis cartridge 220.

[0077] [Fifth embodiment] The steam electrolysis system 10 according to this embodiment differs from the steam electrolysis system 10 according to the fourth embodiment in the configuration of the air supply primary line L10, the absence of the air supply secondary line L20, and the inclusion of a circulation line L90, but is otherwise the same. Therefore, the same components as those in the steam electrolysis system 10 according to the fourth embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0078] As shown in FIG. 14 , the circulation line (heat transfer gas supply line) L90 is a line for extracting the heat transfer gas from the pressure vessel 210 after it has been supplied into the pressure vessel 210 of the electrolysis module 200 and cooled the pressure vessel 210, and for supplying the extracted heat transfer gas back into the pressure vessel 210. The heat transfer gas may be, for example, an inert gas such as air.

[0079] An end of the primary supply main pipe 253 located outside the pressure vessel 210 is connected to one end of a circulation line L90. Also, an end of the primary discharge main pipe 254 located outside the pressure vessel 210 is connected to the other end of the circulation line L90. That is, the circulation line L90 constitutes a system for circulating the heat transfer gas together with the internal space of the pressure vessel 210, which functions as a flow path, and the circulation line L90 is independent of the other lines L10, L30, L40, and L50. Therefore, the type of heat transfer gas flowing in the circulation line L90 does not depend on the type of fluid flowing in the other lines. The primary supply main pipe 253 and the circulation line L90 may be configured as an integrated unit or as separate units. The primary discharge main pipe 254 and the circulation line L90 may be configured as an integrated unit or as separate units. In either case, the primary supply main pipe 253 and / or the primary discharge main pipe 254 can be considered to be part of the circulation line L90.

[0080] The end of the secondary supply main pipe 255 located outside the pressure vessel 210 is connected to the primary air supply line L10. As a result, the air flowing through the primary air supply line L10 is supplied to the electrolysis cartridge 220.

[0081] The end of the secondary main discharge pipe 256 located outside the pressure vessel 210 is connected to the oxygen-enriched air discharge line L50. As a result, the oxygen-enriched air discharged from each electrolysis cartridge 220 is supplied to the turbine 122 via the oxygen-enriched air discharge line L50.

[0082] The circulation line L90 is provided with a heat exchanger L91. The heat exchanger L91 is used as a heat source for heating the feed water. That is, the heat medium gas extracted from the pressure vessel 210 after cooling the pressure vessel 210 is cooled in the heat exchanger L91 and then supplied back into the pressure vessel 210. The heat exchanger L91 is provided in parallel with the other heat exchangers L11, L41, and L51 on the water / steam supply line L30. However, the heat exchangers may be provided in series on the water / steam supply line L30. Alternatively, only some of the heat exchangers may be provided in parallel on the water / steam supply line L30, with the remaining heat exchangers provided in series.

[0083] The steam electrolysis system 10 includes a fourth bypass line L84. The fourth bypass line L84 connects the part of the circulation line L90 upstream of the heat exchanger L91 with the part of the circulation line L90 downstream of the heat exchanger L91, and is a line for mixing the high-temperature heat transfer gas before heat exchange in the heat exchanger L91 with the low-temperature heat transfer gas after heat exchange. The fourth bypass line L84 is provided with a valve 155. Furthermore, the circulation line L90 is provided with a pressure applying means 191 at a portion downstream of the heat exchanger L91. Furthermore, the electrolysis module 200 is provided with a thermometer 183. The control unit 160 obtains the temperature of the heat transfer gas flowing through the circulation line L90 from the thermometer 183, and controls the pressure applying means 191 so that an appropriate amount of heat transfer gas for the operating conditions is supplied to the electrolysis module 200. Examples of the pressure applying means 191 include a compressor and a pump. The control unit 160 also obtains the temperature of the heat medium gas flowing through the circulation line L90 from the thermometer 183 and controls the aperture of the valve 155 so that the temperature of the heat medium gas supplied to the electrolysis module 200 is an appropriate temperature. For example, the control unit 160 can adjust the aperture of the valve 155 to increase the temperature of the heat medium gas (heat medium gas after heat exchange) flowing through the circulation line L90 so that an excessively low-temperature heat medium gas is not supplied to the electrolysis module 200.

[0084] As described above, in the steam electrolysis system 10 of this embodiment, the circulation line L90 is used to extract the heat transfer gas that has cooled the pressure vessel 210 from the pressure vessel 210, and the extracted heat transfer gas is then supplied back into the pressure vessel 210. Furthermore, the flow rate and temperature of the extracted heat transfer gas are adjusted before it is supplied back into the pressure vessel 210.

[0085] According to this embodiment, the following effects are achieved. The system for cooling the inside of the pressure vessel 210 can be separated from other lines, which simplifies the system structure. Furthermore, the type of heat transfer gas flowing through the circulation line L90 does not depend on the type of fluid flowing through the other lines.

[0086] The systems of the respective embodiments can also be applied to systems that perform CO co-electrolysis, which simultaneously electrolyzes water vapor and carbon dioxide, and systems that perform ammonia electrolysis, which simultaneously electrolyzes water vapor and synthesizes ammonia from nitrogen.

[0087] [Note] The cooling method for an electrolysis module and the electrolysis system according to the present disclosure described above can be understood, for example, as follows. A cooling method for an electrolysis module according to a first aspect of the present disclosure is a method for cooling an electrolysis module (200), the method comprising: an electrolysis cell (232) including a hydrogen electrode (232a), an oxygen electrode (232b), and an electrolyte layer (232c) disposed between the hydrogen electrode (232a) and the oxygen electrode (232b); at least one electrolysis cartridge (220) configured to generate hydrogen by electrolyzing water vapor generated from feedwater; and a container (210) accommodating the electrolysis cartridge (220), the method comprising: exchanging heat between a heat transfer gas and the feedwater to heat the feedwater; and supplying the heat-exchanged heat transfer gas to the container (210) to cool the interior of the container (210).

[0088] According to the cooling method for the electrolysis module (200) of this aspect, a heat transfer gas is heat exchanged with the feedwater to heat the feedwater, and the heat-exchanged heat transfer gas is supplied to the container (210). Therefore, the heat transfer gas, whose temperature has been reduced by heat exchange with the feedwater, is supplied to the container (210), thereby lowering the ambient temperature inside the container (210). This allows the use of low-quality materials for the structural members housed inside the container (210), thereby achieving cost reduction. This also serves as a countermeasure against the phenomenon of an increase in the ambient temperature inside the container (210) caused by increasing the pressure of the entire system including the electrolysis module (200). Furthermore, since the feed water can be heated by heat exchange with the heat medium gas, the thermal efficiency of the entire system can be improved.

[0089] According to a second aspect of the present disclosure, in the cooling method for an electrolysis module of the first aspect, the heat transfer gas that has been supplied to the container (210) and cooled the inside of the container (210) is supplied to the electrolysis cartridge (220).

[0090] According to the cooling method for the electrolysis module (200) of this aspect, the heat transfer medium gas that has been supplied to the container (210) and has cooled the interior of the container (210) is supplied to the electrolysis cartridge (220). Therefore, the temperature of the electrolysis cartridge (220) can be maintained at an appropriate temperature by the heat transfer medium gas.

[0091] According to a third aspect of the present disclosure, in the cooling method for an electrolysis module of the second aspect, the heat transfer gas that has been supplied to the container (210) and cooled the inside of the container (210) is supplied to the electrolysis cartridge (220) without being removed from the container (210).

[0092] According to the cooling method for the electrolysis module (200) of this aspect, the heat transfer gas that has been supplied to the container (210) and has cooled the interior of the container (210) is supplied to the electrolysis cartridge (220) without being removed from the container (210). This makes it possible to supply the heat transfer gas to the electrolysis cartridge (220) with a simple structure.

[0093] In a cooling method for an electrolysis module according to a fourth aspect of the present disclosure, in the second aspect, a part of the heat transfer gas that has been supplied to the container (210) and cooled the interior of the container (210) is supplied to the electrolysis cartridge (220), and the remainder of the heat transfer gas that has been supplied to the container (210) and cooled the interior of the container (210) is removed from the container (210).

[0094] According to the cooling method for the electrolysis module (200) of this aspect, a portion of the heat transfer gas that has been supplied to the container (210) and cooled the interior of the container (210) is supplied to the electrolysis cartridge (220), and the remainder of the heat transfer gas that has been supplied to the container (210) and cooled the interior of the container (210) is extracted from the container (210). This makes it possible to prevent an excessive amount of heat transfer gas from being supplied to the electrolysis cartridge (220) for the operating conditions.

[0095] According to a fifth aspect of the present disclosure, in the cooling method for an electrolysis module of the second aspect, the heat transfer gas that has been supplied to the container (210) and cooled the inside of the container (210) is removed from the container (210), a flow rate of the removed heat transfer gas is adjusted, and the flow rate-adjusted heat transfer gas is supplied to the electrolysis cartridge (220).

[0096] According to the cooling method for the electrolysis module (200) of this aspect, the heat transfer gas that has been supplied to the container (210) and cooled the interior of the container (210) is removed from the container (210), the flow rate of the removed heat transfer gas is adjusted, and the flow-rate-adjusted heat transfer gas is supplied to the electrolysis cartridge (220). As a result, the heat transfer gas can be supplied to the electrolysis cartridge (220) at an appropriate flow rate.

[0097] According to a sixth aspect of the present disclosure, in the cooling method for an electrolysis module of the second aspect, the heat transfer gas that has been supplied to the container (210) and cooled the inside of the container (210) is removed from the container (210), the heat transfer gas removed from the container (210) is again subjected to heat exchange with the feedwater, and the heat transfer gas that has been subjected to heat exchange again is supplied to the electrolysis cartridge (220).

[0098] According to the cooling method for the electrolysis module (200) of this aspect, the heat transfer gas that has been supplied to the container (210) and cooled the interior of the container (210) is removed from the container (210), the heat transfer gas removed from the container (210) is again subjected to heat exchange with the feed water, and the heat transfer gas that has been heat exchanged again is supplied to the electrolysis cartridge (220). Thus, the temperature of the heat transfer gas that has increased due to heat exchange with the container (210) can be lowered by heat exchange with the feed water before being supplied to the electrolysis cartridge (220).

[0099] In a cooling method for an electrolysis module according to a seventh aspect of the present disclosure, in the first aspect, the heat transfer gas that has been supplied to the container (210) and cooled the inside of the container (210) is removed from the container (210), the heat transfer gas removed from the container (210) is again subjected to heat exchange with the feedwater, and the heat transfer gas that has been heat exchanged again is again supplied into the container (210).

[0100] According to the cooling method for the electrolysis module (200) of this aspect, the heat transfer gas supplied to the container (210) and having cooled the interior of the container (210) is removed from the container (210), the removed heat transfer gas is again subjected to heat exchange with the feed water, and the heat transfer gas that has been heat exchanged again is again supplied to the container (210). This makes it possible to separate the system for cooling the interior of the container (210), thereby simplifying the system structure.

[0101] According to an eighth aspect of the present disclosure, in the cooling method for an electrolysis module of any one of the first to seventh aspects, the heat transfer gas after heat exchange with the feed water is mixed with the heat transfer gas before heat exchange with the feed water.

[0102] According to the cooling method for the electrolysis module (200) of this aspect, the heat transfer medium gas after heat exchange with the feed water is mixed with the heat transfer medium gas before heat exchange with the feed water. Therefore, the temperature of the air after heat exchange can be adjusted to appropriately control the temperature of the air supplied to the electrolysis module (200), thereby controlling the temperature inside the container (210) and the temperature of the air supplied to the electrolysis cartridge (220).

[0103] A ninth aspect of the present disclosure relates to a cooling method for an electrolysis module of the eighth aspect, and further relates to adjusting a flow rate of the heat transfer gas to be mixed in accordance with at least one of a temperature inside the container (210) and a temperature of the heat transfer gas after heat exchange.

[0104] According to the cooling method for the electrolysis module (200) of this aspect, the flow rate of the heat medium gas to be mixed is adjusted in accordance with at least one of the temperature inside the container (210) and the temperature of the heat medium gas after heat exchange. Therefore, by feeding back the temperature inside the container (210) and the temperature of the heat medium gas after heat exchange, the temperature of the heat medium gas can be maintained at an appropriate temperature.

[0105] An electrolysis system according to a tenth aspect of the present disclosure includes an electrolysis module (200), heat exchangers (L11, L21, L91), and heat transfer medium gas supply lines (L10, L20, L90). The electrolysis module (200) includes at least one electrolysis cartridge (220) and a container (210). The electrolysis cartridge (220) includes an electrolysis chamber including a hydrogen electrode (232a), an oxygen electrode (232b), and an electrolyte layer (232c) disposed between the hydrogen electrode (232a) and the oxygen electrode (232b). The electrolysis system includes a cell (232) and generates hydrogen by electrolyzing water vapor generated from feedwater. The container (210) accommodates the electrolysis cartridge (220). The heat transfer gas supply lines (L10, L20, L90) are lines through which a heat transfer gas flows. The heat transfer gas, which serves as a heat source for heating the feedwater, is supplied to the heat exchangers (L11, L21, L91) and the heat transfer gas that has been heat exchanged in the heat exchangers (L11, L21, L91) is supplied to the container (210).

[0106] In the electrolysis system (10) according to this aspect, the heat transfer medium gas supply lines (L10, L20, L90) are lines through which the heat transfer medium gas flows. The heat transfer medium gas, which serves as a heat source for heating the feedwater, is supplied to the heat exchangers (L11, L21, L91) and the heat transfer medium gas that has undergone heat exchange in the heat exchangers (L11, L21, L91) is supplied to the container (210). Therefore, the heat transfer medium gas whose temperature has been reduced by heat exchange with the feedwater is supplied to the container (210), thereby lowering the ambient temperature inside the container (210). This allows the container (210) to be made of a low-quality material, thereby achieving cost reduction. This also serves as a countermeasure against the phenomenon of an increase in the ambient temperature inside the container (210) due to the increase in pressure of the entire system including the electrolysis module (200). Furthermore, since the feed water can be heated by heat exchange with the heat medium gas, the thermal efficiency of the entire system can be improved.

[0107] According to an eleventh aspect of the present disclosure, in the electrolysis system of the tenth aspect, the heat transfer medium gas supply line (L10, L20, L90) has an outlet through which the supplied heat transfer medium gas is discharged, and the outlet is located inside the container (210). The electrolysis module (200) includes a surrounding member (240, 261) that covers the plurality of electrolysis cartridges (220), and the surrounding member (240, 261) has a heat transfer medium gas intake portion that takes the heat transfer medium gas therein, and is accommodated in the container (210) together with the electrolysis cartridges (220).

[0108] In the electrolysis system (10) according to this aspect, the heat transfer medium gas supply lines (L10, L20, L90) have outlets through which the supplied heat transfer medium gas is discharged. The outlets are located inside the container (210). The electrolysis module (200) includes enclosures (240, 261) that cover the electrolysis cartridges (220). The enclosures (240, 261) have heat transfer medium gas intakes that take in the heat transfer medium gas. The enclosures (240, 261) are housed in the container (210) together with the electrolysis cartridges (220). Therefore, the heat transfer medium gas discharged into the container (210) can be directly taken into the electrolysis cartridges (220) via the heat transfer medium gas intakes. This allows the heat transfer medium gas to be supplied to the electrolysis cartridges (220) using a simple structure.

[0109] According to a twelfth aspect of the present disclosure, in the electrolysis system of the eleventh aspect, the heat transfer gas intake is located on the opposite side of the electrolysis cartridge (220) from the discharge port.

[0110] In the electrolysis system (10) according to this aspect, the heat transfer gas inlet is located on the opposite side of the electrolysis cartridge (220) from the discharge port. This allows the heat transfer gas discharged from the discharge port to easily circulate throughout the container (210) before being taken into the heat transfer gas inlet, thereby enabling the interior of the container (210) to be easily cooled. [Explanation of symbols]

[0111] 10 Steam electrolysis system (electrolysis system) 120 Compression Device 121 Compressor 122 Turbine 123 Electric motor 130 Water supply equipment 140 Power Supply Device 151,152,153,154,155 Valves 160 control section 171,172,173 Flow meter 181,182,183 thermometer 191 Pressure applying means 200 Electrolysis Module 210 Pressure vessels 220 Electrolytic Cartridge 221a Steam supply header 221b Steam supply pipe 221c Hydrogen Discharge Header 221d Hydrogen exhaust pipe 222a Air Supply Header 222b Air supply pipe 222c Oxygen-enriched air discharge header 222d Oxygen-enriched air exhaust pipe 223 Cartridge Insulator 223a Cartridge surrounding insulation 223b Cartridge upper insulation part 223b1 Discharge flow path 223c Cartridge bottom insulation part 223c1 Supply channel 224 Electrolysis chamber (reaction chamber) 230 Cell Stack 231 Base tube 232 Electrolysis Cell 232a Hydrogen electrode 232b Oxygen electrode 232c electrolyte layer 233 Interconnector 234 Lead Film 240 Sub-module insulation material (enclosure material) 241 Submodule Surrounding Insulation 242 Submodule upper insulation section 243 Submodule bottom insulation section 251 Supply main (first embodiment to second embodiment) 252 Main discharge pipe (first embodiment to second embodiment) 253 Primary supply main (third to fifth embodiments) 254 Primary discharge main pipe (third to fifth embodiments) 255 Secondary supply main (third to fifth embodiments) 256 Secondary discharge main pipe (third to fifth embodiments) 261 Closure members (enclosure members) L10 Primary air supply line (heat medium gas supply line) L11 heat exchanger L20 Secondary air supply line (heat medium gas supply line) L21 heat exchanger L30 Water / steam supply line L40 Hydrogen discharge line L41 heat exchanger L50 Oxygen-enriched air discharge line L51 heat exchanger L60 Return line L71 First recirculation line L72 Second recirculation line L81 First Bypass Line L82 Second Bypass Line L83 Third Bypass Line L84 4th Bypass Line L90 Circulation line (heat medium gas supply line) L91 heat exchanger

Claims

1. An electrolytic cell comprising a hydrogen electrode, an oxygen electrode, and an electrolyte layer disposed between the hydrogen electrode and the oxygen electrode, wherein at least one electrolytic cartridge generates hydrogen by electrolyzing water vapor produced from feedwater, A container containing the aforementioned electrolytic cartridge, A method for cooling an electrolytic module, comprising: To heat the feedwater, a heat transfer gas is used to exchange heat with the feedwater. The heat-exchanged heat transfer gas is supplied to the container to cool the inside of the container. Cooling method for electrolytic modules.

2. The heat transfer gas supplied to the container and used to cool the inside of the container is then supplied to the electrolytic cartridge. A method for cooling an electrolytic module according to claim 1.

3. The heat transfer gas supplied to the container and used to cool the inside of the container is supplied to the electrolytic cartridge without being removed from the container. A method for cooling an electrolytic module according to claim 2.

4. A portion of the heat transfer gas supplied to the container and used to cool the inside of the container is supplied to the electrolytic cartridge. The remaining heat transfer gas supplied to the container and used to cool the inside of the container is removed from the container. A method for cooling an electrolytic module according to claim 2.

5. The heat transfer gas supplied to the container and used to cool the inside of the container is removed from the container. The flow rate of the extracted heat transfer gas is adjusted, The flow rate-adjusted heat transfer gas is supplied to the electrolytic cartridge. A method for cooling an electrolytic module according to claim 2.

6. The heat transfer gas supplied to the container and used to cool the inside of the container is removed from the container. The heat transfer gas removed from the container is subjected to heat exchange again with the water supply. The heat transfer gas, which has been heat-exchanged again, is supplied to the electrolytic cartridge. A method for cooling an electrolytic module according to claim 2.

7. The heat transfer gas supplied to the container and used to cool the inside of the container is removed from the container. The heat transfer gas removed from the container is subjected to heat exchange again with the water supply. The heat transfer gas, which has been heat-exchanged again, is supplied back into the container. A method for cooling an electrolytic module according to claim 1.

8. The heat transfer gas that has undergone heat exchange with the water supply is mixed with the heat transfer gas that has undergone heat exchange with the water supply. A method for cooling an electrolytic module according to any one of claims 1 to 7.

9. The flow rate of the heat transfer gas to be mixed is adjusted according to at least one of the temperature inside the container and the temperature of the heat transfer gas after heat exchange. A method for cooling an electrolytic module according to claim 8.

10. Electrolytic module and, A heat exchanger for heating the water supply, Heat transfer gas supply line, Equipped with, The aforementioned electrolytic module is Having at least one electrolytic cartridge and container, The aforementioned electrolytic cartridge is The electrolytic cell comprises a hydrogen electrode, an oxygen electrode, and an electrolyte layer disposed between the hydrogen electrode and the oxygen electrode. Hydrogen is produced by electrolyzing the water vapor generated from the aforementioned water supply. The aforementioned container is The electrolytic cartridge is housed in, The aforementioned heat transfer gas supply line is It is a line through which heat transfer gas flows. The system is configured to supply the heat transfer gas, which serves as a heat source for heating the water supply, to the heat exchanger, and to supply the heat transfer gas, which has undergone heat exchange in the heat exchanger, to the container. Electrolytic system.

11. The heat transfer gas supply line has an outlet through which the supplied heat transfer gas is discharged. The aforementioned outlet is located inside the container, The electrolytic module has a surrounding member that covers a plurality of electrolytic cartridges, The surrounding member is It has a heat transfer gas intake section that takes in the heat transfer gas, The container is housed together with the electrolytic cartridge. The electrolytic system according to claim 10.

12. The heat transfer gas intake section is located on the opposite side of the discharge port from the electrolytic cartridge. The electrolytic system according to claim 11.

Images