Alkaline constant temperature system based on waste heat coupling of hydrogen purification device

Abstract

The present application relates to the technical field of water electrolysis hydrogen production, and particularly relates to an alkali constant temperature system based on waste heat coupling of a hydrogen purification device, which comprises a water electrolysis hydrogen production device, a gas-liquid separation device, a hydrogen purification device, an alkali heat exchanger, an automatic regulating valve and an automatic cut-off valve group. The gas-liquid separation device is used for separating hydrogen and alkali; the hydrogen purification device is used for deoxidizing, drying and regenerating hydrogen; the alkali heat exchanger is connected with the hydrogen purification device and the gas-liquid separation device, and high-temperature waste heat of a purification process is used to provide constant temperature protection for the gas-liquid separation device; the automatic regulating valve dynamically adjusts the circulating water volume; and the automatic cut-off valve group controls the switching of cooling water and constant temperature circulating water. The present application avoids equipment damage and start-up difficulty caused by low-temperature crystallization of alkali by recycling waste heat, reduces heating energy consumption, reduces energy waste, improves operation stability and energy efficiency, and realizes energy recycling and low-carbon operation.

Description

Technical Field

[0001] This invention relates to the field of water electrolysis hydrogen production technology, specifically to an alkaline solution constant temperature system based on waste heat coupling of a hydrogen purification device. Background Technology

[0002] Hydrogen production through water electrolysis is an important method of green energy production, and its application in the industrial sector is becoming increasingly widespread. However, in cold northern regions, the low-temperature environment poses a severe challenge to the stable operation of hydrogen electrolysis systems. Especially in standby gas-liquid separation units, the alkaline solution is prone to crystallization due to low temperatures, leading to difficulties in starting the electrolyzer or even equipment damage. Currently, the industry commonly uses heating within hydrogen-oxygen stations to maintain the temperature, typically requiring 12–16°C. However, due to the flammable and explosive nature of hydrogen, the station building requires exhaust ventilation for safety, resulting in high heating energy consumption and difficulty in maintaining the target temperature. This not only increases operating costs but also affects system reliability.

[0003] Meanwhile, the hydrogen purification unit requires heating the hydrogen with an electric heater during operation to improve deoxygenation and regeneration efficiency, and the subsequent drying and cooling process consumes cooling water to remove heat. The waste heat generated in this process is not effectively utilized and is directly emitted, resulting in energy waste. If this heat can be properly recovered, it can alleviate the energy consumption pressure of the station's heating system and improve the overall energy efficiency of the system. Summary of the Invention

[0004] To address the above technical problems, this invention provides an alkaline solution constant temperature system based on waste heat coupling from a hydrogen purification device.

[0005] The technical problem solved by this invention can be achieved by the following technical solutions:

[0006] An alkaline solution isothermal system based on waste heat coupling from a hydrogen purification device, comprising:

[0007] A water electrolysis hydrogen production unit is used to produce hydrogen and oxygen;

[0008] A gas-liquid separation device is connected to the water electrolysis hydrogen production device and is used to separate hydrogen gas and alkaline solution produced by electrolysis.

[0009] A hydrogen purification device, connected to the gas-liquid separation device, is used for deoxygenation, drying and regeneration of hydrogen.

[0010] An alkaline heat exchanger is used to connect the hydrogen purification device and the gas-liquid separation device through a circulation pipeline, and is used to provide constant temperature protection for the gas-liquid separation device by utilizing the high-temperature waste heat generated during the hydrogen purification process.

[0011] An automatic regulating valve is installed on the circulation pipeline to dynamically regulate the circulation water volume for heat exchange.

[0012] An automatic shut-off valve assembly is installed on the circulation pipeline to control the switching between the station's circulating cooling water and the alkaline constant-temperature circulating water.

[0013] Preferably, the hydrogen purification device includes a purification heat exchanger group, which comprises:

[0014] The first purification heat exchanger is located between the deoxygenation electric heater and the deoxygenation cooler in the hydrogen purification device, and is used for heat exchange with the deoxygenated high-temperature hydrogen.

[0015] The second purification heat exchanger is installed before the regeneration electric heater and regeneration cooler in the hydrogen purification device, and is used to exchange heat with the regenerated high-temperature hydrogen.

[0016] Preferably, the alkaline heat exchanger is an alkaline plate heat exchanger, with its primary side connected to the high-temperature hydrogen waste heat recovery circuit of the deoxygenation and regeneration stage in the hydrogen purification device, and its secondary side connected to the alkaline constant temperature circulation circuit of the gas-liquid separation device.

[0017] Preferably, the gas-liquid separation device is connected to the station building's circulating cooling water system, wherein,

[0018] The circulating water inlet of the gas-liquid separator is connected to the circulating cooling water outlet of the station building's circulating cooling water system.

[0019] The circulating water outlet of the gas-liquid separator is connected to the circulating cooling water inlet of the station building's circulating cooling water system.

[0020] Preferably, the automatic shut-off valve assembly includes:

[0021] A circulating cooling water shut-off valve is installed on the connection pipeline between the gas-liquid separator and the station building's circulating cooling water system to control the flow of cooling water.

[0022] A thermostatic alkali circuit shut-off valve is installed on the connecting pipeline between the gas-liquid separation device and the alkali heat exchanger to control the on / off state of the waste heat circulation.

[0023] A heat source cut-off valve for the purification device is installed on the connecting pipeline between the hydrogen purification device and the alkaline heat exchanger, and is used to control the on / off of waste heat output.

[0024] Preferably, the alkaline solution constant temperature system adopts two sets of parallel gas-liquid separation devices and hydrogen purification devices, including a first gas-liquid separation device and a second gas-liquid separation device, a first hydrogen purification device and a second hydrogen purification device, and the two sets of devices adopt a main-standby redundancy configuration mode, with one set as the main operating equipment and the other set as the standby equipment.

[0025] Preferably, the master / slave switching control logic of the alkali solution constant temperature system is as follows:

[0026] When the first gas-liquid separator and the first hydrogen purification device are operating as the main equipment, the circulating cooling water shut-off valve of the first gas-liquid separator is opened, and the alkali constant temperature circuit shut-off valve is closed; the purification device heat source shut-off valve of the first hydrogen purification device is opened; at the same time, when the second gas-liquid separator and the second hydrogen purification device are operating as backup equipment, the circulating cooling water shut-off valve of the second gas-liquid separator is closed, and the alkali constant temperature circuit shut-off valve is opened; the purification device heat source shut-off valve of the second hydrogen purification device is closed.

[0027] When switching to the second gas-liquid separation device and the second hydrogen purification device, the first gas-liquid separation device and the first hydrogen purification device are in standby mode, and the circulating cooling water shut-off valve of the second gas-liquid separation device and the alkali constant temperature circuit shut-off valve of the first gas-liquid separation device are opened at the same time.

[0028] Preferably, it also includes manual valves, which are arranged in parallel next to each automatic shut-off valve for manually switching pipelines during maintenance or emergency situations.

[0029] Preferably, the automatic regulating valve is located at the primary heat source of the alkaline plate heat exchanger and is used to dynamically adjust the valve opening based on the difference between the real-time alkaline temperature of the gas-liquid separation device in standby mode and the preset temperature T.

[0030] Preferably, the control logic of the automatic regulating valve is as follows:

[0031] The temperature of the alkaline solution in the gas-liquid separator, which is in standby mode, is monitored in real time using a remote temperature sensor.

[0032] When the measured temperature is lower than the preset temperature T, the opening of the automatic regulating valve is increased to increase the amount of waste heat recovery water.

[0033] When the measured temperature is higher than the preset temperature T, the opening of the automatic regulating valve is reduced to reduce the amount of waste heat recovery water.

[0034] Beneficial effects: By adopting the above technical solution, this invention provides constant temperature protection for the gas-liquid separation device by recovering the waste heat of the hydrogen purification process. This not only avoids equipment damage and start-up difficulties caused by low-temperature crystallization of alkaline solution, but also reduces the energy consumption of station heating, reduces energy waste, and improves the system's operational stability and overall energy efficiency, thus realizing the recycling of energy and low-carbon operation. Attached Figure Description

[0035] Figure 1 This is a flowchart of the water electrolysis hydrogen production process of the present invention;

[0036] Figure 2 This is a schematic diagram of the constant temperature control system of the present invention;

[0037] Explanation of reference numerals in the attached drawings: 1. Electrolytic cell; 2. Gas-liquid separation device; 21. First gas-liquid separation device; 22. Second gas-liquid separation device; 3. Hydrogen purification device; 30. First hydrogen purification device; 31. Second hydrogen purification device; 32. Deoxygenation electric heater; 33. First purification heat exchanger; 34. Deoxygenation cooler; 35. Drying tower; 36. Regeneration electric heater; 37. Regeneration tower; 38. Second purification heat exchanger; 39. Regeneration cooler; 4. Alkali plate heat exchanger; 5. Station circulating cooling water system; 6. Circulating cooling water shut-off valve; 7. Alkali constant temperature circuit shut-off valve; 8. Purification device heat source shut-off valve; 9. Manual valve; 10. Automatic regulating valve. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0041] Reference Figure 1 and Figure 2 This invention provides an alkaline solution constant temperature system based on waste heat coupling from a hydrogen purification device, comprising:

[0042] A water electrolysis hydrogen production unit is used to produce hydrogen and oxygen;

[0043] Gas-liquid separation device 2 is connected to the water electrolysis hydrogen production device and is used to separate hydrogen gas and alkaline solution produced by electrolysis.

[0044] Hydrogen purification device 3 is connected to the gas-liquid separation device 2 and is used for deoxygenation, drying and regeneration of hydrogen.

[0045] An alkaline heat exchanger is connected to the hydrogen purification device 3 and the gas-liquid separation device 2 via a circulation pipeline, and is used to provide constant temperature protection for the gas-liquid separation device 2 by utilizing the high-temperature waste heat generated during the hydrogen purification process.

[0046] An automatic regulating valve 10 is installed on the circulation pipeline to dynamically regulate the circulation water volume for heat exchange.

[0047] An automatic shut-off valve assembly is installed on the circulation pipeline to control the switching between the station's circulating cooling water and the alkaline constant-temperature circulating water.

[0048] Specifically, in this embodiment of the invention, the water electrolysis hydrogen production device, the gas-liquid separation device 2, and the hydrogen purification device 3 are optimized and integrated. The high-temperature waste heat generated during the hydrogen purification process is used to provide constant temperature protection for the gas-liquid separation device 2 via an alkaline heat exchanger, preventing the alkaline solution from crystallizing in a low-temperature environment. At the same time, the amount of hot water exchanged is dynamically controlled by the automatic regulating valve 10, and the operation mode of the station circulating cooling water and the alkaline constant temperature circulating water is flexibly switched by the automatic shut-off valve group. While ensuring the safety and stability of the system, the heating energy consumption is effectively reduced, the energy utilization efficiency is improved, and the synergistic optimization of waste heat recovery and temperature control is achieved.

[0049] As a preferred embodiment of the present invention, refer to Figure 1 The hydrogen purification device 3 is equipped with a purification heat exchanger assembly, including:

[0050] The first purification heat exchanger 33 is disposed between the deoxygenation electric heater 32 and the deoxygenation cooler 34 in the hydrogen purification device 3, and is used to exchange heat with the deoxygenated high-temperature hydrogen.

[0051] The second purification heat exchanger 38 is installed before the regeneration electric heater 36 and the regeneration cooler 39 in the hydrogen purification device 3, and is used to exchange heat with the regenerated high-temperature hydrogen.

[0052] Specifically, in the embodiments of this application, the water electrolysis hydrogen production system adopts a three-step process of "electrolysis-gas-liquid separation-purification" during normal production. In the purification stage, the system first performs electric heating deoxygenation treatment on the hydrogen, and then the deoxygenated high-temperature hydrogen exchanges with the alkaline constant-temperature circulating water through the first purification heat exchanger 33, and then enters the deoxygenation cooler 34 for cooling; after cooling, the hydrogen is dried by the drying tower 35, and part of the gas enters the regeneration process, is heated by electric heating, and then undergoes a second heat exchange with the alkaline constant-temperature circulating water through the second purification heat exchanger 38, and finally returns to the hydrogen pipeline before the drying tower 35 after being cooled by the cooler.

[0053] More specifically, in this embodiment of the invention, the purification heat exchanger adopts a two-stage heat exchange design, including a first purification heat exchanger 33 that exchanges heat with the deoxygenated high-temperature hydrogen and a second purification heat exchanger 38 that exchanges heat with the regenerated high-temperature hydrogen. By setting heat exchangers in different process stages, the heat generated in the deoxygenation and regeneration stages can be recovered separately, realizing the cascade utilization of waste heat. The first purification heat exchanger 33 recovers the waste heat of the deoxygenated hydrogen, and the second purification heat exchanger 38 captures the high-temperature heat from the regeneration process. The two heat streams work together through a circulation system to maintain the alkali solution temperature and prevent low-temperature crystallization. This design not only improves the waste heat utilization efficiency but also optimizes the system's thermal balance through multi-stage heat exchange, enhancing the operational stability of the hydrogen production system in cold environments.

[0054] In a preferred embodiment of the present invention, the alkaline heat exchanger is an alkaline plate heat exchanger 4, whose primary side is connected to the high-temperature hydrogen waste heat recovery circuit of the deoxygenation and regeneration stage in the hydrogen purification device 3, and whose secondary side is connected to the alkaline constant temperature circulation circuit of the gas-liquid separation device 2.

[0055] Reference Figure 2 The circulating water outlet on the primary side of the alkali plate heat exchanger 4 is connected to the circulating water inlet of the purification heat exchanger in the hydrogen purification device 3, and the circulating water inlet on the primary side of the alkali plate heat exchanger 4 is connected to the circulating water outlet of the purification heat exchanger in the hydrogen purification device 3. The circulating water outlet on the secondary side of the alkali plate heat exchanger 4 is connected to the circulating water inlet of the gas-liquid separation device 2, and the circulating water inlet on the secondary side of the alkali plate heat exchanger 4 is connected to the circulating water outlet of the gas-liquid separation device 2.

[0056] Specifically, in this embodiment of the invention, by connecting the primary side of the alkaline plate heat exchanger 4 to the high-temperature hydrogen waste heat recovery loops in the deoxygenation and regeneration stages of the hydrogen purification device 3, the graded recovery of heat at different temperatures during the purification process is achieved. Simultaneously, the secondary side of the alkaline plate heat exchanger 4 forms a closed loop with the circulation pipeline of the gas-liquid separation device 2, ensuring that the alkaline temperature is always maintained above the anti-crystallization threshold. This design fully utilizes the process waste heat from the purification process and, through the highly efficient heat transfer characteristics of the alkaline plate heat exchanger 4, completes heat transfer while completely isolating hydrogen and alkaline, thus balancing system safety and energy efficiency.

[0057] As a preferred embodiment of the present invention, refer to Figure 2 The gas-liquid separation device 2 is also connected to the station building's circulating cooling water system 5, wherein...

[0058] The circulating water inlet of the gas-liquid separator 2 is connected to the circulating cooling water outlet of the station building circulating cooling water system 5.

[0059] The circulating water outlet of the gas-liquid separator 2 is connected to the circulating cooling water inlet of the station building circulating cooling water system 5.

[0060] Specifically, in this embodiment of the invention, during the hydrogen production process via water electrolysis, the mixture of hydrogen and alkali solution produced by the electrolyzer 1 enters the gas-liquid separation device 2 at a relatively high temperature. To prevent equipment corrosion or a decrease in gas-liquid separation efficiency due to high temperature, heat exchange is performed between the station's circulating cooling water system 5 and the gas-liquid separation device 2, which can reduce the alkali solution temperature to a suitable operating range.

[0061] More specifically, in this embodiment of the invention, the gas-liquid separation device 2 is bidirectionally connected to the station building circulating cooling water system 5. The circulating water inlet of the gas-liquid separation device 2 is connected to the outlet of the station building cooling water system, while its circulating water outlet is connected back to the inlet of the station building cooling water system. This closed-loop design allows the system to flexibly select the waste heat recovery mode or the circulating cooling mode according to actual operating needs through an automatic shut-off valve: under low-temperature conditions, hydrogen purification waste heat is preferentially used to maintain the alkali solution temperature, while in high-temperature environments, it can automatically switch to the station building cooling water system for auxiliary temperature control, realizing seamless connection and synergistic optimization of circulating cooling and waste heat utilization.

[0062] As a preferred embodiment of the present invention, refer to Figure 2 The automatic shut-off valve assembly includes:

[0063] The circulating cooling water shut-off valve 6 is installed on the connecting pipeline between the gas-liquid separator 2 and the station building circulating cooling water system 5, and is used to control the on / off of cooling water.

[0064] The alkali constant temperature circuit shut-off valve 7 is installed on the connecting pipeline between the gas-liquid separation device 2 and the alkali plate heat exchanger 4, and is used to control the on / off of the waste heat circulation.

[0065] The heat source cut-off valve 8 of the purification device is installed on the connecting pipeline between the hydrogen purification device 3 and the alkaline plate heat exchanger 4, and is used to control the on / off of waste heat output.

[0066] Specifically, in this embodiment of the invention, the automatic shut-off valve group is designed to enable intelligent switching between system operation and standby states. The circulating cooling water shut-off valve 6 opens during device operation to ensure normal cooling of the gas-liquid separator 2; the alkali constant temperature circuit shut-off valve 7 opens when the device is in standby mode, utilizing the residual heat from the purification unit to maintain the alkali temperature and prevent crystallization; the purification unit heat source shut-off valve 8 controls the residual heat output according to the operating status of the purification unit, ensuring precise heat distribution. Through the linkage control of the automatic regulating valve 10, the system can dynamically adjust the amount of water exchanged according to actual needs, maintaining a constant temperature target, thereby significantly improving energy utilization efficiency and ensuring stable operation of the equipment in cold environments.

[0067] As a preferred embodiment of the present invention, a bypass pipeline is added at the circulating water inlet of the gas-liquid separation device 2. When the equipment is in standby mode, the circulating cooling water circuit is closed by an automatic shut-off valve and the alkaline constant temperature circulation circuit is opened, so that the high-temperature waste heat from the electric heating stage of the hydrogen purification device 3 continuously provides a heat source for the standby gas-liquid separation device 2 through the alkaline heat exchanger.

[0068] Specifically, refer to Figure 2 The alkaline constant temperature system uses two sets of parallel gas-liquid separation devices 2 and hydrogen purification devices 3, including a first gas-liquid separation device 21 and a second gas-liquid separation device 22, a first hydrogen purification device 30 and a second hydrogen purification device 31, and the two devices operate in a one-in-one standby mode.

[0069] More specifically, in this embodiment of the invention, the system's operation control logic is as follows:

[0070] 1. Master / Slave Switchover Control Logic:

[0071] When the first set of devices (the first gas-liquid separation device 21 and the first hydrogen purification device 30) is running as the main equipment, the circulating cooling water shut-off valve 6 of the first gas-liquid separation device 21 is opened, the alkali constant temperature circuit shut-off valve 7 is closed, and the purification device heat source shut-off valve 8 of the first hydrogen purification device 30 is opened; at this time, the second set of devices (the second gas-liquid separation device 22 and the second hydrogen purification device 31) is used as a standby device, the circulating cooling water shut-off valve 6 of the second gas-liquid separation device 22 is closed, the alkali constant temperature circuit shut-off valve 7 of the second gas-liquid separation device 22 is opened, and the purification device heat source shut-off valve 8 of the second hydrogen purification device 31 is closed;

[0072] When switching to the second unit, the system automatically shuts down the operating circuit of the first unit and simultaneously opens the circulating cooling water circuit of the second unit and the constant temperature circulation circuit of the alkali solution of the first unit, achieving a seamless switch.

[0073] 2. Waste heat utilization control logic:

[0074] The high-temperature hydrogen waste heat generated during the deoxygenation and regeneration process of the operating hydrogen purification unit 3 is recovered through the purification heat exchanger; the recovered waste heat is transferred to the standby gas-liquid separation unit 2 through the alkaline plate heat exchanger 4 to maintain its alkaline temperature.

[0075] 3. Security protection mechanism logic:

[0076] Physical isolation is provided between the two sets of equipment to ensure that the hydrogen circuit and the alkali circuit do not come into direct contact.

[0077] All automatic valves are interlocked with the system control center, and will immediately shut off in case of any abnormality.

[0078] The backup unit is always kept in a hot standby state to ensure that it can be switched to operation at any time.

[0079] Based on this, by setting up two sets of parallel devices and an intelligent switching control system, three core advantages are achieved: First, the high-temperature waste heat from the deoxygenation and regeneration stages during hydrogen purification is used to provide a constant-temperature heat source for the backup gas-liquid separation device 2, which not only solves the problem of alkali crystallization in cold regions but also significantly reduces the energy consumption of traditional heating; Second, the use of fully automatic valve groups and interlocking control strategies ensures continuous and stable temperature field during the switching of the main and backup devices, greatly improving system reliability; Finally, through physical isolation design and multiple safety interlocking mechanisms, energy cascade utilization is achieved while fully meeting the inherent safety requirements of the hydrogen system, providing an innovative solution for the safe and efficient operation of water electrolysis hydrogen production systems in extreme environments.

[0080] As a preferred embodiment of the present invention, the system further includes a manual valve 9, which is arranged in parallel next to each automatic shut-off valve for manually switching pipelines during maintenance or emergency situations.

[0081] Specifically, in this embodiment of the invention, a manual valve 9 is added as a redundancy guarantee. Each manual valve 9 is arranged in parallel with its corresponding automatic shut-off valve, forming a dual control architecture of "automatic priority, manual backup": during normal operation, the automatic shut-off valve enables intelligent switching to ensure rapid system response; when encountering equipment maintenance, system debugging, or sudden failures, operators can immediately activate the manual valve 9 to take over pipeline control, which not only avoids operational interruptions caused by automatic system failures but also provides a safe isolation means for maintenance operations. This design significantly improves the reliability and maintainability of the system, ensuring the advantages of automated control while providing an indispensable manual emergency intervention channel for key hydrogen production equipment, fully meeting the stringent safety requirements of chemical production.

[0082] In a preferred embodiment of the present invention, the automatic regulating valve 10 is located at the primary heat source of the alkaline plate heat exchanger 4 and is used to dynamically adjust the valve opening according to the difference between the real-time alkaline temperature of the gas-liquid separation device 2 in standby state and the preset anti-crystallization temperature T, thereby accurately controlling the amount of waste heat recovery water flowing through the primary side of the alkaline plate heat exchanger 4.

[0083] The control logic of the automatic regulating valve 10 achieves closed-loop regulation through a remote temperature signal. Specifically, it includes:

[0084] The system uses a remote temperature sensor to collect the temperature of the alkali solution in the gas-liquid separator 2, which is in standby mode, in real time, and compares it with the preset anti-crystallization temperature T.

[0085] When the measured temperature is lower than the preset anti-crystallization temperature T, the automatic regulating valve 10 increases the opening degree and increases the amount of waste heat recovery water.

[0086] When the measured temperature is higher than the preset anti-crystallization temperature T, the automatic regulating valve 10 reduces its opening to reduce the amount of waste heat recovery water.

[0087] Specifically, in this embodiment of the invention, the automatic regulating valve 10 achieves precise temperature management of the standby gas-liquid separator 2 through closed-loop control: real-time temperature data of the alkali solution is collected by a temperature remote sensor and fed back to the controller via a temperature remote signal a. When the detected temperature is lower than the preset anti-crystallization temperature T, the regulating valve automatically increases its opening to increase the amount of waste heat recovery water; conversely, when the temperature exceeds the preset anti-crystallization temperature T, the opening decreases to reduce heat input. This dynamic regulation mechanism can achieve rapid response and stable control through a PID algorithm, ensuring that the alkali solution in the standby gas-liquid separator 2 is always maintained within the optimal temperature range, such as 12-16℃. This effectively prevents the risk of low-temperature crystallization and avoids energy waste, while also achieving safe and reliable automated operation through interlocking with the main system.

[0088] In a preferred embodiment of the present invention, the preset temperature T is determined based on the anti-crystallization characteristics of the alkaline solution in the gas-liquid separation device 2 and the operating environment.

[0089] Specifically, in this embodiment of the invention, the determination of the preset temperature T comprehensively considers key parameters such as alkali concentration, ambient temperature threshold, and system safety margin. First, a basic temperature threshold is set based on the characteristics of alkali concentration (e.g., the crystallization point of 30% KOH solution is -15℃). Second, a safety margin of 5-8℃ is added based on local extreme low temperature records (e.g., -30℃). Finally, the optimal temperature range is set through system thermodynamic simulation and measured data verification. This setting ensures that the alkali remains liquid at the lowest ambient temperature, avoids energy waste caused by overheating through precise temperature control of the waste heat recovery system, and meets the anti-crystallization requirements of electrolytes with different concentrations, providing reliable thermal management for the system.

[0090] In summary, this invention provides an alkaline solution constant temperature system based on waste heat coupling from a hydrogen purification unit. By recovering the high-temperature waste heat generated during the deoxygenation and regeneration stages of hydrogen purification, it provides constant temperature protection for the gas-liquid separation unit 2 in standby mode, preventing alkaline solution crystallization due to low temperatures. The system includes a water electrolysis hydrogen production unit, a gas-liquid separation unit 2, a hydrogen purification unit 3, an alkaline solution heat exchanger, an automatic regulating valve 10, and an automatic shut-off valve group, achieving efficient utilization of waste heat and intelligent switching between main and standby equipment. Its core innovation lies in utilizing the waste heat generated by the purification unit to maintain the temperature of the standby gas-liquid separation unit 2 through heat exchange, solving the operational challenges of electrolysis hydrogen production systems in low-temperature environments in cold northern regions.

[0091] The beneficial effects of this system are mainly reflected in the following aspects: First, waste heat recovery significantly reduces the energy consumption for heating the station, thus reducing operating costs; second, it avoids equipment start-up difficulties or damage caused by alkali crystallization, improving the system's reliability and stability; finally, the intelligent valve control logic enables seamless switching between main and backup equipment and precise temperature regulation, further optimizing energy utilization efficiency. Overall, this system not only improves the energy efficiency of the electrolytic hydrogen production process but also provides a feasible technical solution for the promotion and application of green energy production in cold regions.

[0092] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A constant-temperature alkaline solution system based on waste heat coupling from a hydrogen purification device, characterized in that, include: A water electrolysis hydrogen production unit is used to produce hydrogen and oxygen; A gas-liquid separation device is connected to the water electrolysis hydrogen production device and is used to separate hydrogen gas and alkaline solution produced by electrolysis. A hydrogen purification device, connected to the gas-liquid separation device, is used for deoxygenation, drying and regeneration of hydrogen. An alkaline heat exchanger is used to connect the hydrogen purification device and the gas-liquid separation device through a circulation pipeline, and is used to provide constant temperature protection for the gas-liquid separation device by utilizing the high-temperature waste heat generated during the hydrogen purification process. An automatic regulating valve is installed on the circulation pipeline to dynamically regulate the circulation water volume for heat exchange. An automatic shut-off valve assembly is installed on the circulation pipeline to control the switching between the station's circulating cooling water and the alkaline constant-temperature circulating water. The alkaline constant temperature system uses two sets of parallel gas-liquid separation devices and hydrogen purification devices, including a first gas-liquid separation device and a second gas-liquid separation device, a first hydrogen purification device and a second hydrogen purification device. The two sets of devices adopt a main-standby redundancy configuration mode, with one set as the main operating equipment and the other set as the standby equipment. The master / standby switching control logic of the alkaline solution constant temperature system is as follows: When the first gas-liquid separator and the first hydrogen purification device are operating as the main equipment, the circulating cooling water shut-off valve of the first gas-liquid separator is opened, and the alkali constant temperature circuit shut-off valve is closed; the purification device heat source shut-off valve of the first hydrogen purification device is opened; at the same time, when the second gas-liquid separator and the second hydrogen purification device are operating as backup equipment, the circulating cooling water shut-off valve of the second gas-liquid separator is closed, and the alkali constant temperature circuit shut-off valve is opened; the purification device heat source shut-off valve of the second hydrogen purification device is closed. When switching to the second gas-liquid separation device and the second hydrogen purification device, the first gas-liquid separation device and the first hydrogen purification device are in standby mode, and the circulating cooling water shut-off valve of the second gas-liquid separation device and the alkali constant temperature circuit shut-off valve of the first gas-liquid separation device are opened at the same time.

2. The alkaline solution constant temperature system based on waste heat coupling of a hydrogen purification device according to claim 1, characterized in that, The hydrogen purification device is equipped with a purification heat exchanger group, which includes: The first purification heat exchanger is located between the deoxygenation electric heater and the deoxygenation cooler in the hydrogen purification device, and is used for heat exchange with the deoxygenated high-temperature hydrogen. The second purification heat exchanger is installed before the regeneration electric heater and regeneration cooler in the hydrogen purification device, and is used to exchange heat with the regenerated high-temperature hydrogen.

3. The alkaline solution constant temperature system based on waste heat coupling of a hydrogen purification device according to claim 1, characterized in that, The alkaline heat exchanger is an alkaline plate heat exchanger, with its primary side connected to the high-temperature hydrogen waste heat recovery circuit in the deoxygenation and regeneration stage of the hydrogen purification device, and its secondary side connected to the alkaline constant temperature circulation circuit of the gas-liquid separation device.

4. The alkaline solution constant temperature system based on waste heat coupling of a hydrogen purification device according to claim 3, characterized in that, The gas-liquid separation device is connected to the station building's circulating cooling water system, wherein... The circulating water inlet of the gas-liquid separator is connected to the circulating cooling water outlet of the station building's circulating cooling water system. The circulating water outlet of the gas-liquid separator is connected to the circulating cooling water inlet of the station building's circulating cooling water system.

5. The alkaline solution constant temperature system based on waste heat coupling of a hydrogen purification device according to claim 1, characterized in that, The automatic shut-off valve assembly includes: A circulating cooling water shut-off valve is installed on the connection pipeline between the gas-liquid separator and the station building's circulating cooling water system to control the flow of cooling water. A thermostatic alkali circuit shut-off valve is installed on the connecting pipeline between the gas-liquid separation device and the alkali heat exchanger to control the on / off state of the waste heat circulation. A heat source cut-off valve for the purification device is installed on the connecting pipeline between the hydrogen purification device and the alkaline heat exchanger, and is used to control the on / off of waste heat output.

6. The alkaline solution constant temperature system based on waste heat coupling of a hydrogen purification device according to claim 1, characterized in that, It also includes manual valves, which are connected in parallel next to each automatic shut-off valve and are used to manually switch pipelines during maintenance or emergency situations.

7. The alkaline solution constant temperature system based on waste heat coupling of a hydrogen purification device according to claim 1, characterized in that, The automatic regulating valve is located at the primary heat source of the alkaline plate heat exchanger and is used to dynamically adjust the valve opening based on the difference between the real-time alkaline temperature of the gas-liquid separation device in standby mode and the preset temperature T.

8. The alkaline solution constant temperature system based on waste heat coupling of a hydrogen purification device according to claim 7, characterized in that, The control logic of the automatic regulating valve is as follows: The temperature of the alkaline solution in the gas-liquid separator, which is in standby mode, is monitored in real time using a remote temperature sensor. When the measured temperature is lower than the preset temperature T, the opening of the automatic regulating valve is increased to increase the amount of waste heat recovery water. When the measured temperature is higher than the preset temperature T, the opening of the automatic regulating valve is reduced to reduce the amount of waste heat recovery water.

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