Electrolytic hydrogen production system

Abstract

The utility model discloses an electrolytic hydrogen production system which comprises an electrolysis device, a gas-liquid separation device, a phase change heat storage device and a cooling water device which are sequentially connected through pipelines in the flowing direction of electrolyte, and the electrolyte output end of the gas-liquid separation device is further connected with the electrolyte input end of the cooling water device through a pipeline. The electrolyte output end of the phase change heat storage device is further connected with the electrolyte input end of the electrolysis device through a pipeline. The system; the electrolysis device, the phase change heat storage device and the cooling water device are sequentially arranged in the flowing direction of the electrolyte, so that when the electrolysis device works normally, heat generated by electrolysis of the electrolyte can exchange heat with a phase change material in the phase change heat storage device; and heat generated in the electrolysis process can be absorbed into the phase change heat storage device to be reused, and energy consumption is reduced. When the electrolytic bath stops working, heat stored in the phase-change material exchanges heat with the flowing electrolyte, and the heat is used for maintaining the temperature of the electrolysis system at a relatively high temperature, so that when the electrolytic bath is restarted, the starting time is greatly shortened, and the electrolysis efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of hydrogen production technology, and in particular to an electrolytic hydrogen production system. Background Technology

[0002] Hydrogen production through water electrolysis is a technology that uses electricity as the input energy source to split water into hydrogen and oxygen. It can be powered by electricity generated from renewable energy sources such as wind and solar power, producing hydrogen with almost zero carbon emissions, making it one of the key technologies for green hydrogen production.

[0003] Hydrogen energy, as a clean secondary energy source, has broad application prospects in transportation, industry, and energy storage. Currently, the water electrolysis technology used in China to achieve large-scale renewable energy consumption for hydrogen production is generally alkaline water electrolysis. However, alkaline electrolysis devices typically require a stable power supply. These devices generally heat up during startup through the electrolysis reaction, a very slow process that keeps the device operating at low temperatures for extended periods. Furthermore, for fluctuating renewable energy sources, heat management significantly impacts the efficiency and safety of alkaline hydrogen production. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide an electrolytic hydrogen production system that makes full use of the internal heat of the system and improves the start-up efficiency of the system.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] This application discloses an electrolytic hydrogen production system, comprising: an electrolysis device, a gas-liquid separation device, a phase change heat storage device, and a cooling water device connected sequentially along the flow direction of the electrolyte via pipelines. The electrolyte output end of the gas-liquid separation device is also connected to the electrolyte input end of the cooling water device via a pipeline, and the electrolyte output end of the phase change heat storage device is also connected to the electrolyte input end of the electrolysis device via a pipeline.

[0007] In some embodiments of this application, the phase change heat storage device is provided with a phase change material, and the phase change temperature range of the phase change material is 50℃~85℃.

[0008] In some embodiments of this application, the electrolyte output terminal of the phase change heat storage device is connected to the electrolyte input terminal of the electrolysis device through a first pipeline. A first circulation pump and a first control valve are sequentially provided on the first pipeline. The electrolyte input terminal of the cooling water device is connected to the first pipeline between the first circulation pump and the first control valve.

[0009] In some embodiments of this application, the system includes a second pipeline and a third pipeline. The electrolyte input terminal of the cooling water device is connected to the electrolyte output terminal of the gas-liquid separation device through the second pipeline, and a first valve body is provided on the second pipeline. The electrolyte input terminal of the phase change heat storage device is connected to the electrolyte output terminal of the gas-liquid separation device through the third pipeline, and a second valve body is provided on the third pipeline.

[0010] In some embodiments of this application, the gas-liquid separation device includes a first sub-gas-liquid separation device and a second sub-gas-liquid separation device. The input end of the first sub-gas-liquid separation device is connected to the electrolysis device for separating and purifying hydrogen produced by the electrolysis device. The input end of the second sub-gas-liquid separation device is connected to the electrolysis device for separating and purifying oxygen produced by the electrolysis device.

[0011] In some embodiments of this application, the first sub-gas-liquid separation device includes a first separator, a first scrubber, and a first cooler, wherein the first separator, the first scrubber, and the first cooler are arranged sequentially along the flow direction of hydrogen; the first sub-gas-liquid separation device further includes a first sub-pipeline, wherein the first sub-pipeline connects the bottom of the first separator to the second pipeline;

[0012] The second sub-gas-liquid separation device includes a second separator, a second scrubber, and a second cooler, which are arranged sequentially along the oxygen flow direction; the second sub-gas-liquid separation device also includes a second sub-pipeline, which connects the bottom of the second separator to the third pipeline.

[0013] In some embodiments of this application, a second check valve is provided between the first washer and the first cooler, and a third check valve is provided between the second washer and the second cooler.

[0014] In some embodiments of this application, the system further includes a detergent replenishment device, which is connected to the first washer and the second washer respectively to deliver detergent to the first washer and the second washer.

[0015] In some embodiments of this application, the system includes one electrolysis device; or, the system includes multiple electrolysis devices connected in parallel.

[0016] In some embodiments of this application, the outer periphery of the electrolysis device, the gas-liquid separation device, the phase change heat storage device, the cooling water device, and the connecting pipelines therebetween are all covered with thermal insulation material.

[0017] Beneficial effects:

[0018] The electrolytic hydrogen production system provided in this application, by sequentially arranging an electrolysis device, a phase change heat storage device, and a cooling water device along the flow direction of the electrolyte, allows the heat generated by the electrolysis of the electrolyte to exchange heat with the phase change material in the phase change heat storage device during normal operation of the electrolysis device. This enables the heat generated during the electrolysis process to be absorbed into the phase change heat storage device for reuse, reducing energy consumption. Furthermore, it increases the temperature of the electrolyte when the system is shut down, thereby increasing the standby temperature of the system and enabling the system to switch from cold start to hot start, significantly reducing start-up time. Attached Figure Description

[0019] Figure 1 A schematic diagram of an electrolytic hydrogen production system provided in one embodiment of this application.

[0020] Figure 2 A schematic diagram of an electrolytic hydrogen production system provided for another embodiment of this application.

[0021] Figure 3 A schematic diagram of an electrolytic hydrogen production system provided in another embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the flow trajectory of the electrolyte in the heat storage state of the electrolytic hydrogen production system provided in one embodiment of this application.

[0023] Figure 5 This is a schematic diagram of the flow trajectory of the electrolyte in an exothermic state in an electrolytic hydrogen production system provided in one embodiment of this application.

[0024] Explanation of main component symbols: 1. Electrolysis device; 2. Gas-liquid separation device; 201. First separator; 202. First scrubber; 203. First cooler; 204. Second separator; 205. Second scrubber; 206. Second cooler; 207. First sub-pipeline; 208. Second sub-pipeline; 3. Phase change heat storage device; 4. Cooling water device; 5. First pipeline; 6. First circulating pump; 7. First control valve; 8. Hydrogen storage device; 9. Oxygen storage device; 10. Scrubber replenishment device; 11. Electrolyte replenishment device; 12. Second circulating pump; 13. Third pump body; 14. Second check valve; 15. Third check valve; 16. Fourth check valve; 17. Fifth check valve; 18. Second pipeline; 19. Third pipeline; 20. First valve body; 21. Second valve body; 22. Fourth pipeline; 23. Fifth pipeline. Detailed Implementation

[0025] This application provides an electrolytic hydrogen production system. To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following detailed description is provided with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit this application.

[0026] In the description of this application, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicating orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limitations on this application. Furthermore, "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] Please see Figures 1 to 3 This application provides an electrolytic hydrogen production system, specifically a water electrolysis hydrogen production system. The system includes: an electrolysis unit 1, a gas-liquid separation unit 2, a phase change heat storage unit 3, and a cooling water unit 4, connected sequentially along the electrolyte flow direction via pipelines. The electrolyte output end of the gas-liquid separation unit 2 is also connected to the electrolyte input end of the cooling water unit 4 via a pipeline, and the electrolyte output end of the phase change heat storage unit 3 is also connected to the electrolyte input end of the electrolysis unit 1 via a pipeline. By installing the phase change heat storage unit 3 between the electrolysis unit 1 and the cooling water unit 4, the electrolyte, after being heated by electrolysis, enters the phase change heat storage unit 3 for heat exchange after gas-liquid separation. This allows the heat generated by the electrolysis of the electrolyte to be reused, reducing system energy consumption and improving economic efficiency to some extent. Furthermore, the system does not require an additional heat exchanger connected to the phase change heat storage unit, reducing equipment cost and size.

[0029] The electrolyte contains water. By energizing the electrolysis device 1, the water undergoes an electrochemical reaction, decomposing into hydrogen and oxygen. During electrolysis, an oxidation reaction occurs at the anode (positive electrode), where water molecules lose electrons and are oxidized to oxygen; a reduction reaction occurs at the cathode (negative electrode), where water molecules gain electrons and are reduced to hydrogen. By controlling the electrolysis conditions, such as current intensity, electrolysis time, and electrolyte composition, the generation rate and purity of hydrogen and oxygen can be controlled.

[0030] The electrolyte also includes an alkaline solution. Specifically, the alkaline solution can be a soluble alkaline solution such as sodium hydroxide or potassium hydroxide. Since pure water has poor conductivity and cannot produce hydrogen in large quantities, adding an alkaline solution to the electrolyte can significantly improve the conductivity of the electrolyte, thereby accelerating the electrolysis of water, reducing the energy consumption of the electrolysis process, and improving the electrolysis efficiency.

[0031] The phase change heat storage device 3 contains a phase change material, which has a high heat storage density and stable thermal properties. When the temperature changes, the phase change material can absorb or release a large amount of heat, thus achieving energy storage and release. This allows the phase change heat storage device 3 to store the thermal energy from the high-temperature electrolyte in the phase change material when the electrolysis device 1 is operating normally. When the electrolysis device 1 stops working, the phase change material provides a stable heat source, exchanging heat with the electrolyte that has passed through the phase change heat storage device 3, thereby increasing the temperature of the electrolyte in the system and improving energy utilization efficiency.

[0032] In some embodiments, the phase change material has a phase change temperature range of 50°C to 85°C. In alkaline electrolysis hydrogen production processes, to improve electrolysis efficiency and reduce electrode overpotential, the electrolysis unit 1 typically operates at a relatively high temperature, generally 80°C to 90°C. Using a phase change material with a phase change temperature range of 50°C to 85°C ensures that all components of the system are sufficiently preheated before the system operates normally, shortening the start-up time.

[0033] Specifically, the phase change material can be selected from inorganic salt aqueous solution, paraffin, and alcohol solution. Preferably, the phase change material is an inorganic salt aqueous solution, such as hydrated salt Ba(OH)2·8H2O. The phase change temperature of Ba(OH)2·8H2O is 78℃, which is close to the normal operating temperature of electrolysis device 1, and it has a high latent heat of phase change of 265kJ / Kg, which can quickly absorb or release a large amount of heat, thus reducing the volume of phase change heat storage device 3 to some extent.

[0034] In some embodiments of this application, the electrolyte output terminal of the phase change heat storage device 3 is connected to the electrolyte input terminal of the electrolysis device 1 via a first pipeline 5, allowing the electrolyte after heat exchange to re-enter the electrolysis device 1 and circulate to other components in the system. A first circulation pump 6 and a first control valve 7 are sequentially mounted on the first pipeline 5. The electrolyte input terminal of the cooling water device 4 is connected to the first pipeline 5 between the first circulation pump 6 and the first control valve 7. By adjusting the opening and closing of the first control valve 7, the electrolyte exiting the phase change heat storage device 3 can enter the cooling water device 4 or re-enter the electrolysis device 1.

[0035] An electrolyte replenishment device 11 is also provided upstream of the first circulation pump 6. The electrolyte replenishment device 11 is connected to the first pipeline 5 and replenishes the electrolyte to the electrolytic cell 1 through the first circulation pump 6.

[0036] The system is also equipped with a second circulation pump 12, through which the cooling water device 4 delivers cooling water to the gas-liquid separator 2 for washing or cooling the gas.

[0037] Figure 4 This is a schematic diagram of the flow trajectory of the electrolyte in the regenerated state of the electrolytic hydrogen production system provided in this application. Figure 5 This is a schematic diagram of the electrolyte flow trajectory under exothermic conditions in the electrolytic hydrogen production system provided in this application. Figure 4 and Figure 5 As shown, when the electrolysis device 1 is working normally, the system is in a heat storage state, the check valve is closed, and the electrolyte enters the cooling water device 4 for cooling after passing through the phase change heat storage device. When the electrolysis device 1 stops working, the system is in a heat release state, the check valve is open, the electrolyte exchanges heat with the phase change material and then enters the electrolysis device 1, circulating in the system to increase the system's standby temperature and shorten the system restart time.

[0038] In some embodiments of this application, the system includes a second pipeline 18 and a third pipeline 19. The electrolyte input terminal of the cooling water device 4 is connected to the electrolyte output terminal of the gas-liquid separator 2 via the second pipeline 18, and a first valve body 20 is provided on the second pipeline 18. The electrolyte input terminal of the phase change heat storage device 3 is connected to the electrolyte output terminal of the gas-liquid separator 2 via the third pipeline 19, and a second valve body 21 is provided on the third pipeline 19. Connecting the electrolyte output terminal of the gas-liquid separator 2 and the electrolyte input terminal of the cooling water device 4 via the second pipeline 18, and connecting the electrolyte input terminal of the phase change heat storage device 3 and the electrolyte output terminal of the gas-liquid separator 2 via the third pipeline 19, ensures that the electrolyte can circulate in the system.

[0039] In another embodiment, the electrolyte can be discharged from the electrolyte output end of the gas-liquid separator 2 through the same pipeline, and then connected to the electrolyte input end of the cooling water device 4 and the electrolyte input end of the phase change heat storage device 3 through different pipelines, which simplifies the pipeline structure and optimizes the system structure.

[0040] The first valve body 20 and the second valve body 21 can be flow valves. The first valve body 20 can be used to control the flow rate of the electrolyte entering the cooling water device 4. The second valve body 21 can be used to control the flow rate of the electrolyte entering the phase change heat storage device 3.

[0041] Specifically, the system also includes an oxygen storage device 9 and a hydrogen storage device 8. The gas-liquid separation device 2 includes a first sub-gas-liquid separation device and a second sub-gas-liquid separation device. The first sub-gas-liquid separation device is used to separate and purify hydrogen. The second sub-gas-liquid separation device is used to separate and purify oxygen.

[0042] The first sub-gas-liquid separation device includes a first separator 201, a first scrubber 202, and a first cooler 203. The first separator 201, first scrubber 202, and first cooler 203 are arranged sequentially along the hydrogen flow direction. The first sub-gas-liquid separation device includes a first sub-pipeline 207, and a first sub-pipeline 191 connecting the bottom drain port of the first separator 201 to a second pipe 18 and a third pipe 19. The first separator 201 is connected to the electrolysis device 1 via a fourth pipe 22 to discharge the hydrogen produced after electrolysis into the first separator 201, separating the electrolyte carried in the hydrogen. The separated electrolyte enters the cooling water device 4 through the first sub-pipeline 207 and the second pipe 18, and enters the phase change heat storage device 3 through the first sub-pipeline 207 and the third pipe 19. The hydrogen after gas-liquid separation enters the first scrubber 202 to remove other impurities, then enters the first cooler 203 for liquefaction, and finally is stored in the hydrogen storage device 8.

[0043] A second check valve 14 is provided between the first scrubber 202 and the first cooler 203 to prevent hydrogen in the first cooler 203 from flowing back into the first scrubber 202.

[0044] The second sub-gas-liquid separation device 2 includes a second separator 204, a second scrubber 205, and a second cooler 206. The second separator 204, second scrubber 205, and second cooler 206 are arranged sequentially along the oxygen flow direction. The second sub-gas-liquid separation device 2 includes a second sub-pipeline 208, which connects the bottom drain port of the second separator 204 to a third pipe 19. The second separator 204 is connected to the electrolysis device 1 via a fifth pipe 23 to discharge the oxygen generated after electrolysis into the second separator 204, separating the electrolyte carried in the oxygen. The separated electrolyte enters the cooling water device 4 through the second sub-pipeline 208 and the second pipe 18, and enters the phase change heat storage device 3 through the second sub-pipeline 208 and the third pipe 19. The oxygen after gas-liquid separation enters the first scrubber 202 to remove other impurities, then enters the second cooler 206 for liquefaction, and finally is stored in the oxygen storage device 9.

[0045] A third check valve 15 is provided between the second scrubber 205 and the second cooler 206 to prevent oxygen in the second cooler 206 from flowing back into the second scrubber 205.

[0046] Furthermore, the system also includes a washing liquid replenishment device 10 and a third pump body 13. The washing liquid replenishment device 10 is connected to the first scrubber 202 and the second scrubber 205, respectively. In this embodiment, the washing liquid is purified water. The washing liquid replenishment device 10 delivers purified water to the first scrubber 202 and the second scrubber 205 through the third pump body 13, so as to provide purified water for washing hydrogen in the first scrubber 202 and purified water for washing oxygen in the second scrubber 205.

[0047] A fourth check valve 16 is provided on the connecting pipe between the washing liquid replenishment device 10 and the first washer 202, and a fifth check valve 17 is provided on the connecting pipe between the washing liquid replenishment device 10 and the second washer 205 to prevent pure water from flowing back.

[0048] like Figure 1 As shown, in some embodiments of this application, an electrolysis device 1 is provided in the system.

[0049] For most engineering applications, several or even dozens of electrolysis units are typically used simultaneously to improve hydrogen production efficiency.

[0050] like Figure 2 As shown, the system is equipped with multiple electrolysis devices 1, which are connected in parallel.

[0051] like Figure 3 As shown, multiple units of this system can also be used in parallel.

[0052] In some embodiments of this application, to reduce system heat loss and energy consumption, the outer periphery of the electrolysis device 1, gas-liquid separation device 2, phase change heat storage device 3, cooling water device 4, and the connecting pipelines between them are all covered with insulation material. The insulation material can be selected from high-efficiency thermal insulation materials such as silicates, rock wool, glass wool, aerogel, polyurethane foam, or polystyrene foam. These insulation materials have excellent thermal insulation properties, effectively reducing heat transfer and maintaining stable internal system temperature, thereby improving energy utilization efficiency and reducing energy consumption.

[0053] Another aspect of this application provides a method for producing hydrogen by electrolysis, which is applied to the aforementioned hydrogen production system by electrolysis, and the method includes:

[0054] S1. When the electrolysis device 1 is working normally, the system is in a heat storage state. The electrolyte can exchange heat with the phase change material in the phase change heat storage device 3 to transfer the heat generated by the electrolyte to the phase change material.

[0055] Specifically, the phase transition temperature of the phase change material is T0, the normal operating temperature of the system is T1, and the standby temperature of the system is T2, and T2 <T0<T1。

[0056] When electrolysis unit 1 is operating normally, the electrolyte in electrolysis unit 1 undergoes an electrochemical reaction, absorbing heat and raising its temperature to T1. The hydrogen and oxygen produced by electrolysis are discharged from electrolysis unit 1, carrying the high-temperature electrolyte. The mixed gas enters gas-liquid separator 2, where the high-temperature electrolyte is separated and discharged into phase change heat storage unit 3. Heat is transferred to the phase change material through the heat exchange coils in phase change heat storage unit 3, causing the phase change material to absorb heat and melt into a liquid state. After heat exchange, the temperature of the electrolyte decreases to slightly above the phase change temperature T0 of the phase change material, and then it enters cooling water device 4 for cooling. After cooling, the electrolyte re-enters electrolysis unit 1 for the next cycle.

[0057] S2. When the electrolysis device 1 stops working, the system is in an exothermic state. The electrolyte in the phase change heat storage device 3 can exchange heat with the phase change material to increase the temperature of the electrolyte in the system.

[0058] When the electrolysis device 1 stops working, the first circulation pump 6 works normally, the system's cooling equipment stops working, the electrolyte passes through the phase change heat storage device 3, and absorbs the latent heat of phase change through the heat exchange coil inside the phase change heat storage device 3. At the same time, the phase change material undergoes phase change solidification, and the heated electrolyte circulates in the system to maintain the system at the set standby temperature T2.

[0059] During the startup of an alkaline electrolysis hydrogen production system, the electrolyte must first be heated to a suitable temperature range, and all components in the system must be fully preheated. The hydrogen production method provided in this application can transfer the heat of the electrolyte to the phase change material during normal system operation. When the system stops working, it can fully utilize the latent heat of phase change of the phase change material, ensuring that all components are fully preheated. This allows the electrolyte temperature to rapidly rise from the set standby temperature T2 to the normal operating temperature T1 when the electrolysis unit 1 is restarted, transforming a conventional cold start into a hot start and significantly reducing startup time.

[0060] Understandably, the size of the phase change thermal storage device 3 can be determined based on the longest possible downtime and the heat dissipation of the electrolysis unit 1 during that period. To ensure the reliability of system operation, the phase change thermal storage device 3 can store no less heat than the system's heat dissipation when the electrolysis unit 1 stops working, ensuring that the system is in a pre-start state during downtime, so that all indicators are stable before system startup and the system startup efficiency is improved.

[0061] To better explain the solution of this application, some specific embodiments are provided below to further illustrate this application.

[0062] Example 1

[0063] This embodiment provides a water electrolysis control process with a phase change thermal accumulator, using one 1200NM unit.3 / h alkaline electrolysis unit, the heat dissipation area of ​​the system components' outer surface is approximately 70m². 2 The electrolysis unit is shut down and maintained at a temperature of 60℃, while the ambient temperature is 15℃. After heat preservation, the electrolysis unit naturally dissipates heat from the outside environment. The thermal power of the electrolysis unit when shut down and maintained at a constant 60℃ is 3.15kW. The phase change temperature of the heat storage agent Ba(OH)₂·8H₂O is 78℃, and the latent heat of phase change is 265kJ / kg. To maintain the electrolysis unit at a constant 60℃ for 5 hours, approximately 232kg of the heat storage agent Ba(OH)₂·8H₂O is used. During heat storage, the temperature difference between the electrolyte and the heat storage material is approximately 7–12℃; during heat release, the temperature difference is approximately 10–18℃.

[0064] Example 2

[0065] This embodiment provides a water electrolysis control process with a phase change thermal accumulator, using one 1200NM unit. 3 / h alkaline electrolysis unit, the heat dissipation area of ​​the system components' outer surface is approximately 70m². 2 The electrolysis unit is shut down and maintained at a temperature of 60℃, while the ambient temperature is -15℃. After insulation, the electrolysis unit dissipates heat naturally from the outside environment. The thermal power of the electrolysis unit when shut down and maintained at a constant temperature of 60℃ is 5.25kW. Paraffin-based heat storage agent C is used. 34 H 70 Phase change temperature 74℃, latent heat of phase change 260kJ / kg, maintaining electrolysis unit at 60℃ for 8 hours, heat storage agent C 34 H 70 The dosage is approximately 582 kg. To enhance the thermal conductivity of paraffin-based materials, a small amount of graphite powder or copper powder is added to form a mixture with the paraffin. During heat storage, the temperature difference between the electrolyte and the heat storage material is approximately 10–15°C, and during heat release, the temperature difference is approximately 10–18°C.

[0066] Example 3

[0067] This embodiment provides a water electrolysis control process with a phase change thermal accumulator, using one 1200NM unit. 3 / h alkaline electrolysis unit, the heat dissipation area of ​​the system components' outer surface is approximately 70m². 2 The electrolysis unit is shut down and maintained at a temperature of 60℃, while the ambient temperature is -15℃. After insulation, the electrolysis unit dissipates heat naturally from the outside environment. The thermal power of the electrolysis unit when shut down and maintained at a constant temperature of 60℃ is 5.25kW. Paraffin-based heat storage agent C is used. 34 H 70 Phase change temperature 74℃, latent heat of phase change 260kJ / kg, assuming the electrolysis unit is maintained at a constant 60℃ for 16h, heat storage agent C 34 H 70The required amount is approximately 582 kg (enough to maintain a constant temperature for 8 hours). A 6 kW electric heater is connected in series after the heat accumulator. Operating for 8 hours results in a total duration of 16 hours, consuming 48 kWh of electricity in those 8 hours. Connecting a small-power electric heater in series can solve problems caused by insufficient heat accumulator capacity due to prolonged shutdowns or extreme cold weather, saving electricity while addressing the issues associated with large heat accumulator capacities. To enhance the thermal conductivity of paraffin-based materials, a small amount of graphite powder or copper powder is added to create a mixture with the paraffin. During heat storage, the temperature difference between the electrolyte and the heat storage material is approximately 10–15°C; during heat release, the temperature difference is approximately 10–18°C.

[0068] The three embodiments described above employ different phase change materials according to different application environment requirements, all of which enable the hydrogen production system to effectively store heat during normal operation and maintain an effective preheating state during shutdown by utilizing the latent heat of phase change. Therefore, the hydrogen production system disclosed in this application can fully utilize the heat inside the system, absorbing a portion of the heat generated during the electrolysis process into the phase change heat storage device, reducing energy consumption, effectively shortening start-up time, and improving start-up efficiency.

[0069] It is understood that those skilled in the art can make equivalent substitutions or changes based on the technical solution and concept of this application, and all such substitutions or changes should fall within the protection scope of the appended claims.

Claims

1. An electrolytic hydrogen production system, characterized in that, include: An electrolysis device, a gas-liquid separation device, a phase change heat storage device, and a cooling water device are connected in sequence through pipelines along the flow direction of the electrolyte. The electrolyte output end of the gas-liquid separation device is also connected to the electrolyte input end of the cooling water device through a pipeline, and the electrolyte output end of the phase change heat storage device is also connected to the electrolyte input end of the electrolysis device through a pipeline.

2. The electrolytic hydrogen production system of claim 1, wherein, The phase change heat storage device is equipped with a phase change material, and the phase change temperature range of the phase change material is 50℃~85℃.

3. The electrolytic hydrogen production system of claim 1, wherein, The electrolyte output terminal of the phase change heat storage device is connected to the electrolyte input terminal of the electrolysis device through a first pipeline. A first circulation pump and a first control valve are sequentially provided on the first pipeline. The electrolyte input terminal of the cooling water device is connected to the first pipeline between the first circulation pump and the first control valve.

4. The electrolytic hydrogen production system of claim 1, wherein, The system includes a second pipeline and a third pipeline. The electrolyte input terminal of the cooling water device is connected to the electrolyte output terminal of the gas-liquid separation device through the second pipeline, and a first valve body is provided on the second pipeline. The electrolyte input terminal of the phase change heat storage device is connected to the electrolyte output terminal of the gas-liquid separation device through the third pipeline, and a second valve body is provided on the third pipeline.

5. The electrolytic hydrogen production system of claim 4, wherein, The gas-liquid separation device includes a first sub-gas-liquid separation device and a second sub-gas-liquid separation device. The input end of the first sub-gas-liquid separation device is connected to the electrolysis device and is used to separate and purify the hydrogen produced by the electrolysis device. The input end of the second sub-gas-liquid separation device is connected to the electrolysis device and is used to separate and purify the oxygen produced by the electrolysis device.

6. The electrolytic hydrogen production system of claim 5, wherein, The first sub-gas-liquid separation device includes a first separator, a first scrubber, and a first cooler, which are arranged sequentially along the flow direction of hydrogen. The first sub-gas-liquid separation device also includes a first sub-pipeline, which connects the bottom of the first separator to the second pipeline. The second sub-gas-liquid separation device includes a second separator, a second scrubber, and a second cooler, which are arranged sequentially along the oxygen flow direction; the second sub-gas-liquid separation device also includes a second sub-pipeline, which connects the bottom of the second separator to the third pipeline.

7. The electrolytic hydrogen production system of claim 6, wherein, A second check valve is provided between the first washer and the first cooler, and a third check valve is provided between the second washer and the second cooler.

8. The electrolytic hydrogen generation system of claim 6, wherein, The system also includes a detergent replenishment device, which is connected to the first washer and the second washer respectively, to deliver detergent to the first washer and the second washer.

9. The electrolytic hydrogen generation system of claim 1, wherein, The system may have one electrolysis device; or the system may have multiple electrolysis devices connected in parallel.

10. The electrolytic hydrogen generation system of claim 1, wherein, The outer periphery of the electrolysis device, the gas-liquid separation device, the phase change heat storage device, the cooling water device, and the connecting pipelines between them are all covered with thermal insulation material.

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