Hydrogen production system and method for producing hydrogen by electrolyzing water

Abstract

The invention provides a hydrogen production system and a method for producing hydrogen by electrolyzing water. The hydrogen production system comprises an electrolytic bath, a gas-liquid separation device, a hydrogen side buffer tank and an oxygen side buffer tank, the number of the electrolytic cells is the same as that of the gas-liquid separation devices, each gas-liquid separation device comprises a hydrogen side separation device and an oxygen side separation device, and each electrolytic cell is correspondingly connected with one hydrogen side separation device and one oxygen side separation device; the hydrogen side buffer tank comprises a first hydrogen side buffer tank, the oxygen side buffer tank comprises a first oxygen side buffer tank, and the hydrogen side buffer tank and the oxygen side buffer tank are each provided with a first liquid inlet; a liquid outlet of each hydrogen side separation device is connected with a first liquid inlet of the first hydrogen side buffer tank, and a liquid outlet of each oxygen side separation device is connected with a first liquid inlet of the first oxygen side buffer tank; wherein the number of the separating devices is greater than that of the corresponding buffer tanks. Therefore, the gas flow path of each electrolytic cell can be independent, and the operation stability and the anti-interference capability of each electrolytic cell are improved.

Description

Technical Field

[0001] This application relates to the field of gas-liquid separation technology, and in particular to a hydrogen production system and a method for producing hydrogen by water electrolysis. Background Technology

[0002] Hydrogen production systems typically include multiple electrolyzers and separation equipment. The separation equipment is used to separate the gas-liquid mixture produced by electrolysis in the electrolyzers to improve the purity of the gas.

[0003] However, in existing hydrogen production systems, mutual interference can easily occur between the various electrolyzers, leading to unstable operation of the electrolyzers. During system startup or load fluctuations, gas purity indicators may fail to meet standards, which can trigger system alarms or interlock shutdowns. Summary of the Invention

[0004] In view of this, this application provides a hydrogen production system and a method for producing hydrogen by water electrolysis, so as to at least solve the problem that mutual interference between various electrolyzers in existing hydrogen production systems can easily occur, leading to unstable system operation.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows: This application provides a hydrogen production system, including at least two electrolyzers, at least two sets of gas-liquid separation devices, at least one hydrogen-side buffer tank and at least one oxygen-side buffer tank; The number of electrolytic cells is the same as the number of gas-liquid separation devices. Each gas-liquid separation device includes a hydrogen-side separation device and an oxygen-side separation device. Each electrolytic cell is connected to one hydrogen-side separation device and one oxygen-side separation device. The hydrogen-side buffer tank includes a first hydrogen-side buffer tank, and the oxygen-side buffer tank includes a first oxygen-side buffer tank. The first hydrogen-side buffer tank and the first oxygen-side buffer tank are respectively provided with a first liquid inlet. The liquid outlet of each hydrogen-side separation device is connected to the first liquid inlet of the first hydrogen-side buffer tank, and the liquid outlet of each oxygen-side separation device is connected to the first liquid inlet of the first oxygen-side buffer tank. The number of hydrogen-side separation devices is greater than the number of hydrogen-side buffer tanks, and the number of oxygen-side separation devices is greater than the number of oxygen-side buffer tanks.

[0006] This application also provides a method for producing hydrogen by electrolysis of water using a hydrogen production system. The hydrogen production system includes at least two electrolyzers, at least two sets of gas-liquid separation devices, at least two gas purity detection devices, a first gas processing system, and a second gas processing system. The gas-liquid separation devices include a hydrogen-side separation device and an oxygen-side separation device, with each electrolyzer correspondingly connected to one hydrogen-side separation device and one oxygen-side separation device. Each set of gas-liquid separation devices is connected to at least one gas purity detection device. The method for producing hydrogen by electrolysis of water using the hydrogen production system includes: Step S1: Use the gas purity detection device to detect the purity of the gas separated by the gas-liquid separator; Step S2: When the gas purity detection device detects that the gas purity is qualified, the gas separated by the gas-liquid separation device is controlled to flow to the first gas processing system; or, when the gas purity detection device detects that the gas purity is unqualified, the gas separated by the gas-liquid separation device is controlled to flow to the second gas processing system.

[0007] Compared with existing technologies, the hydrogen production system described in this application has the following advantages: The hydrogen production system of this application arranges electrolyzers and gas-liquid separation devices in a one-to-one manner. That is, each electrolyzer is connected to a hydrogen-side separation device and an oxygen-side separation device, which enables the gas flow path of each electrolyzer to be completely independent. This avoids problems such as mutual interference between electrolyzers, large system pressure fluctuations, and system instability that occur when multiple electrolyzers share a separation device. At the same time, the independent gas flow path can be specifically matched to the operating parameters of each electrolyzer, such as gas production rate and pressure, and can quickly and accurately locate the faulty electrolyzer. Even if some electrolyzers start up, stop, or adjust their load, it will not affect the working status of other electrolyzers. This effectively improves the operational stability and anti-interference capability of each electrolyzer and avoids the problem of interlocking shutdown of electrolyzers.

[0008] Furthermore, the hydrogen production system of this application connects the liquid outlets of each hydrogen-side separation unit to the first hydrogen-side buffer tank, and the liquid outlets of each oxygen-side separation unit to the first oxygen-side buffer tank. This ensures that the alkaline solutions separated by each hydrogen-side separation unit are collected in the first hydrogen-side buffer tank, and the alkaline solutions separated by each oxygen-side separation unit are collected in the first oxygen-side buffer tank. Utilizing the volumetric buffering effect of the first oxygen-side buffer tank and the first hydrogen-side buffer tank, the pressure at the liquid outlets of all separation units on the same side (i.e., the hydrogen side or the oxygen side) tends to be consistent, thereby ensuring the internal pressure balance of each separation unit and avoiding problems such as incomplete gas-liquid separation, gas entrainment of liquid, or liquid retention caused by abnormal pressure in a single separation unit. Simultaneously, the alkaline solutions separated by the hydrogen-side and oxygen-side separation units are correspondingly transported to the hydrogen-side buffer tank and oxygen-side buffer tank for storage, reuse, and further gas-liquid separation. This structurally reduces the contact channels between hydrogen and oxygen, thereby reducing the mixing of hydrogen and oxygen and helping to control the mixed concentration of hydrogen and oxygen within a safe range, thus improving the safety of the hydrogen production system. Attached Figure Description

[0009] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is one of the schematic diagrams of a hydrogen production system in the embodiments of this application; Figure 2 This is a second schematic diagram of a hydrogen production system in the embodiments of this application; Figure 3 This is the third schematic diagram of a hydrogen production system in the embodiments of this application; Figure 4 This is a schematic diagram of a washing tower according to an embodiment of this application.

[0010] Explanation of reference numerals in the attached figures: 1-Electrolyzer, 2-Gas-liquid separation unit, 21-Hydrogen-side separation unit, 22-Oxygen-side separation unit 31 - First hydrogen-side buffer tank, 32 - First oxygen-side buffer tank 4-Alkali cooling device, 41-First cooler, 42-Second cooler 5 - Circulation pump set, 51 - First circulation pump, 52 - Second circulation pump, 61-Hydrogen-side scrubbing unit, 62-Oxygen-side scrubbing unit, 71 - Hydrogen side gas outlet pipe, 72 - Oxygen side gas outlet pipe, 73 - Hydrogen side liquid outlet pipe, 74 - Oxygen side liquid outlet pipe. 81 - Hydrogen-side gas cooling device; 82 - Oxygen-side gas cooling device; 83 - Hydrogen-side gas-water separator; 84 - Oxygen-side gas-water separator. 6-Scrubber; 601-Bubbling section; 602-Spray section; 603-Packing section; 604-Liquid collection section; 611-Make-up water pipe; 621-First outlet pipe; 622-Second outlet pipe; 63-Liquid pump; 64-First regulating valve; 65-Second regulating valve; 66-Liquid level monitoring device; 67-First pressure monitoring device; 68-Second pressure monitoring device 91-First connecting pipe, 911-First branch pipe, 912-Second branch pipe, 92-Second connecting pipe 900 - Pressure control valve, a - First inlet, b - Second inlet. Detailed Implementation

[0011] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0012] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0013] The term "comprising" or any other variations thereof in the specification and claims of this application is intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0014] The following detailed description of a hydrogen production system and a method for producing hydrogen by water electrolysis, provided in this application, is illustrated with specific embodiments.

[0015] In a first aspect, embodiments of this application provide a hydrogen production system, referring to... Figure 1 and Figure 2The diagrams show schematic representations of the hydrogen production system in embodiments of this application. The hydrogen production system includes at least two electrolyzers 1, at least two sets of gas-liquid separation devices 2, at least one hydrogen-side buffer tank, and at least one oxygen-side buffer tank. The number of electrolyzers 1 is the same as the number of gas-liquid separation devices 2. Each gas-liquid separation device 2 includes one hydrogen-side separation device 21 and one oxygen-side separation device 22. Each electrolyzer 1 is connected to one hydrogen-side separation device 21 and one oxygen-side separation device 22. The hydrogen-side buffer tank includes a first hydrogen-side buffer tank 31, and the oxygen-side buffer tank includes a first oxygen-side buffer tank 32. The first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are each provided with a first inlet a. The outlet of each hydrogen-side separation device 21 is connected to the first inlet a of the first hydrogen-side buffer tank 31, and the outlet of each oxygen-side separation device 22 is connected to the first inlet a of the first oxygen-side buffer tank 32. The number of hydrogen-side separation devices 21 is greater than the number of hydrogen-side buffer tanks, and the number of oxygen-side separation devices 22 is greater than the number of oxygen-side buffer tanks.

[0016] Specifically, the electrolyzer 1, as the core reaction unit of the hydrogen production system, can generate hydrogen and oxygen from the electrolyte-containing mixture through electrolysis. The hydrogen production system of this application is applied in an alkaline water electrolysis hydrogen production system, and the electrolyte-containing mixture is simply referred to as "alkaline solution". The hydrogen-side separation device 21 and the oxygen-side separation device 22 form a gas-liquid separation device 2. The number of gas-liquid separation devices 2 corresponds one-to-one with the number of electrolyzers 1, that is, each electrolyzer 1 is connected to one hydrogen-side separation device 21 and one oxygen-side separation device 22.

[0017] Each hydrogen-side separation device 21 and oxygen-side separation device 22 is equipped with an inlet, an outlet, and a liquid outlet. The inlet of each hydrogen-side separation device 21 is connected to the hydrogen outlet of the corresponding electrolytic cell 1, so that the hydrogen produced in the electrolytic cell 1 is input into the hydrogen-side separation device 21 for gas-liquid separation to separate the hydrogen from the carried alkaline solution. The inlet of each oxygen-side separation device 22 is connected to the oxygen outlet of the corresponding electrolytic cell 1, so that the oxygen produced in the electrolytic cell 1 is input into the oxygen-side separation device 22 for gas-liquid separation to separate the oxygen from the carried alkaline solution.

[0018] The hydrogen production system of this embodiment also includes at least one hydrogen-side buffer tank and at least one oxygen-side buffer tank. The hydrogen-side buffer tank includes a first hydrogen-side buffer tank 31, and the oxygen-side buffer tank includes a first oxygen-side buffer tank 32. The first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are used for centralized storage of the alkaline solution. Figure 2As shown, the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are each equipped with a first inlet a. The outlets of all hydrogen-side separation devices 21 are connected to the first inlet a of the first hydrogen-side buffer tank 31 through a common pipe, and the outlets of all oxygen-side separation devices 22 are connected to the first inlet a of the first oxygen-side buffer tank 32 through a common pipe. This achieves the connection between the hydrogen-side separation device 21 and the first hydrogen-side buffer tank 31, and between the oxygen-side separation device 22 and the first oxygen-side buffer tank 32. This allows the alkaline solution separated by the gas-liquid separation device 2 to flow into the corresponding buffer tank. The buffer tank can better absorb the impact caused by changes in gas production during fluctuations in the hydrogen production system load, keeping the liquid level and pressure of the gas-liquid separation device 2 within a stable range, preventing local liquid level imbalances, and avoiding sudden changes in alkaline concentration within the electrolyzer 1, thus better ensuring the stable operation of the system.

[0019] The number of hydrogen-side separation devices 21 is greater than the number of hydrogen-side buffer tanks, and the number of oxygen-side separation devices 22 is greater than the number of oxygen-side buffer tanks. When there are two or more hydrogen-side buffer tanks and oxygen-side buffer tanks, all hydrogen-side buffer tanks and all oxygen-side buffer tanks can be connected in series. First, the first hydrogen-side buffer tank 31 collects the alkali solution from all hydrogen-side separation devices 21, and the first oxygen-side buffer tank 32 collects the alkali solution from all oxygen-side separation devices 22. Then, the other hydrogen-side buffer tanks further divert and store the alkali solution collected by the first hydrogen-side buffer tank 31, and the other oxygen-side buffer tanks further divert and store the alkali solution collected by the first oxygen-side buffer tank 32. This can further extend the separation time of residual gas in the alkali solution, reduce the amount of residual gas in the alkali solution, and prevent residual hydrogen and oxygen from entering the electrolyzer 1 and mixing, thereby improving gas purity and stabilizing the pipeline pressure when the alkali solution returns to the electrolyzer 1.

[0020] For example, when there are two electrolyzers 1 in the hydrogen production system, there are also two hydrogen-side separation devices 21 and two oxygen-side separation devices 22. The outlets of the two hydrogen-side separation devices 21 are connected to the first hydrogen-side buffer tank 31 through a common pipe, and the outlets of the two oxygen-side separation devices 22 are connected to the first oxygen-side buffer tank 32 through a common pipe. When there are three or more electrolyzers 1, the outlets of three or more hydrogen-side separation devices 21 are connected to the first hydrogen-side buffer tank 31 through a common pipe, and the outlets of three or more oxygen-side separation devices 22 are connected to the first oxygen-side buffer tank 32 through a common pipe.

[0021] The first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 can be equipped with pressure monitoring interfaces, replenishment ports, and drain ports to achieve centralized storage of alkali solution, equalization of gas pressure within the tanks and the connected gas-liquid separation devices 2, and recycling of the alkali solution. Independent sealed pipes can be installed between all hydrogen-side separation devices 21 and the hydrogen outlet of the corresponding electrolyzer 1, and between all oxygen-side separation devices 22 and the oxygen outlet of the corresponding electrolyzer 1. These pipes are equipped with check valves or flow regulating valves to prevent reverse flow in the gas paths.

[0022] The hydrogen production system of this application arranges electrolyzers 1 and gas-liquid separators 2 in a one-to-one configuration. That is, each electrolyzer 1 is connected to a hydrogen-side separator 21 and an oxygen-side separator 22. Compared with the traditional system where multiple electrolyzers 1 share a single gas-liquid separator, this improves the operational stability and anti-interference capability of each electrolyzer 1. Specifically, the one-to-one dedicated configuration of electrolyzer 1 with hydrogen-side separators 21 and oxygen-side separators 22 allows the gas flow path of each electrolyzer 1 to be completely independent, avoiding problems such as mutual interference between electrolyzers, large system pressure fluctuations, and system instability that occur when multiple cells share a separator. At the same time, the independent gas flow path can be specifically matched to the operating parameters of each electrolyzer 1, such as gas production rate and pressure, and can quickly and accurately locate faulty electrolyzers 1. Even if some electrolyzers 1 start, stop, or have their load adjusted, it will not affect the working status of other electrolyzers 1, thereby effectively improving the operational stability and anti-interference capability of each electrolyzer 1 and avoiding the problem of interlocking shutdown of electrolyzers 1.

[0023] Furthermore, the hydrogen production system of this application connects the liquid outlet of each hydrogen-side separation device 21 to the first hydrogen-side buffer tank 31, and the liquid outlet of each oxygen-side separation device 22 to the first oxygen-side buffer tank 32. This allows the alkaline solution separated by each hydrogen-side separation device 21 to be collected in the first hydrogen-side buffer tank 31, and the alkaline solution separated by each oxygen-side separation device 22 to be collected in the first oxygen-side buffer tank 32. By utilizing the volume buffering effect of the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32, the liquid outlet pressure of all separation devices on the same side (i.e., the hydrogen side or the oxygen side) can be made consistent, thereby ensuring the internal pressure balance of each separation device and avoiding problems such as incomplete gas-liquid separation, gas entrainment of liquid, or liquid retention caused by abnormal pressure of a single separation device. Meanwhile, the alkaline solutions separated by the hydrogen-side separation device 21 and the oxygen-side separation device 22 are respectively transported to the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 for storage, reuse, and further gas-liquid separation. This can structurally reduce the contact channels between hydrogen and oxygen, thereby reducing the mixing of hydrogen and oxygen. This helps to control the mixed concentration of hydrogen and oxygen within a safe range and improves the safety of the hydrogen production system.

[0024] Optionally, in some embodiments of this application, the number of hydrogen-side buffer tanks is at least two, and all hydrogen-side buffer tanks are connected in series; and / or, the number of oxygen-side buffer tanks is at least two, and all oxygen-side buffer tanks are connected in series.

[0025] Specifically, the number of hydrogen-side buffer tanks is set to two or more, and the multiple hydrogen-side buffer tanks are connected in series with each other and also connected in series with the first hydrogen-side buffer tank 31. The number of oxygen-side buffer tanks is set to two or more, and the multiple oxygen-side buffer tanks are connected in series with each other and also connected in series with the first oxygen-side buffer tank 32. In this way, the pressure of the alkaline solution separated by the gas-liquid separator 2 can be gradually released and buffered, realizing the diversion and storage of the alkaline solution, significantly increasing the total volume used to hold the alkaline solution. At the same time, the multiple buffer tanks connected in series can extend the separation time of gas in the alkaline solution, further improving the efficiency of gas-liquid separation, reducing the amount of gas entrained in the alkaline solution, and improving the gas purity.

[0026] Optionally, in some embodiments of this application, reference is made to Figure 2 The hydrogen production system also includes an alkali cooling device 4 and a first connecting pipe 91. The first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are respectively provided with a second liquid inlet b. The alkali cooling device 4 includes an inlet end and an outlet end that are connected to its internal cooling channel. The inlet end is connected to the outlet of the first hydrogen-side buffer tank 31 and the outlet of the first oxygen-side buffer tank 32, respectively. The outlet end is connected to one end of the first connecting pipe 91. The other end of the first connecting pipe 91 branches to form a first branch pipe 911 and a second branch pipe 912. The first branch pipe 911 is connected to the electrolyzer 1. The second branch pipe 912 is connected to the second liquid inlet b of the first hydrogen-side buffer tank 31 and the second liquid inlet b of the first oxygen-side buffer tank 32, respectively.

[0027] Specifically, the alkali cooling device 4 has a cooling channel and an inlet and an outlet connected to the cooling channel. The cooling channel is used to circulate the alkali solution that needs to be cooled. In addition, the alkali cooling device 4 also has a water channel and an inlet and an outlet connected to the water channel. The channel is used to circulate cooling water. The alkali solution is cooled by heat exchange between the cooling water and the alkali solution in the cooling channel during the circulation process. Of course, the cooling water can be pure water, industrial circulating water, organic solution, etc. This embodiment does not limit its type.

[0028] The outlet of the alkali cooling device 4 is connected to the electrolytic cell 1 via a first branch pipe 911, and to the second inlet b of the first hydrogen-side buffer tank 31 and the second inlet b of the first oxygen-side buffer tank 32 via a second branch pipe 912. This forms a closed-loop circulation path from the buffer tank to the alkali cooling device 4, and from the alkali cooling device 4 to the electrolytic cell 1. This allows the alkali flowing out of the buffer tank to be cooled by the alkali cooling device 4 and then returned to the electrolytic cell 1 for reuse, improving the economic efficiency of the alkali circulation system. Meanwhile, the second branch pipe 912 is connected to the second inlet b of the corresponding buffer tank. This is equivalent to setting up a branch pipe that returns to the buffer tank on the pipeline from the buffer tank to the electrolyzer 1. When the load of the hydrogen production system fluctuates, the flow rate of the alkali returning to the buffer tank can be adjusted through the second branch pipe 912. Furthermore, the internal space of the buffer tank allows for a large adjustment range of the alkali flow rate, which in turn can regulate the flow rate of the alkali from the buffer tank to the electrolyzer 1. This ensures that the pressure of the alkali pipeline from the buffer tank to the electrolyzer 1 can be maintained at a preset value, without significant fluctuations due to load fluctuations. This makes the flow rate regulation of the alkali entering the electrolyzer 1 more stable and precise, which helps to reduce the impact on the alkali circulation pump caused by pressure fluctuations in the alkali pipeline. This, in turn, helps to reduce the energy consumption of the hydrogen production system and improve the purity of the gas.

[0029] Furthermore, the hydrogen production system may also include a second connecting pipe 92. When there are multiple hydrogen-side buffer tanks and oxygen-side buffer tanks, the outlets of both the hydrogen-side and oxygen-side buffer tanks can be connected to the second connecting pipe 92. The inlet of the alkali cooling device 4 is connected to the second connecting pipe 92, and the alkali solution in each hydrogen-side and oxygen-side buffer tank is transported to the alkali cooling device 4 for cooling through the second connecting pipe 92. When the hydrogen-side buffer tanks consist only of the first hydrogen-side buffer tank 31, and the oxygen-side buffer tanks consist only of the first oxygen-side buffer tank 32, the outlets of both the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are connected to the second connecting pipe 92. This means that the hydrogen-side buffer tank and the oxygen-side buffer tank are connected through the second connecting pipe 92, enabling the hydrogen-side buffer tank and the oxygen-side buffer tank to form a pressure adaptive balance system. When the pressure difference in the buffer tank is caused by gas evolution or fluctuations in the alkaline solution circulation rate, the two buffer tanks can achieve bidirectional flow of alkaline solution through the second connecting pipe 92 to quickly compensate for the pressure difference, so that the system pressure on both sides of hydrogen and oxygen is always maintained within a reasonable range, ensuring the stable operation of the system.

[0030] Optionally, in some embodiments of this application, reference is made to Figure 2A pressure control valve is installed on the second branch pipe 912. That is, a pressure control valve 900 is installed on the branch pipe where the alkali solution returns to the buffer tank. The pressure control valve 900 is used to regulate and stabilize the pressure in the second branch pipe 912. Since the second branch pipe 912 is a branch pipe of the first connecting pipe 91 and the two are connected to each other, the pressure in the second branch pipe 912 is the same as that in the first connecting pipe 91. Therefore, the pressure control valve 900 can also be regarded as being used to regulate and stabilize the pressure in the first connecting pipe 91.

[0031] In this embodiment, a pressure detection device can also be installed on the front end of the first connecting pipe 91 or on the second branch pipe 912, and the pressure control valve 900 and the pressure detection device can be electrically connected. When the pressure detection device detects that the pressure of the first connecting pipe 91 is high, the valve opening of the pressure control valve 900 can be increased, allowing more alkali solution to flow back into the corresponding buffer tank through the second branch pipe 912. When the pressure detection device detects that the pressure of the first connecting pipe 91 is low, the valve opening of the pressure control valve 900 can be decreased, allowing less alkali solution to flow back into the corresponding buffer tank through the alkali solution return branch pipe, or no alkali solution to flow back. By adjusting the opening of the pressure control valve 900 to regulate the flow rate of the refluxed alkali solution, the pressure of the first connecting pipe 91 can be maintained at a preset value.

[0032] In this embodiment of the application, an alkali flow detection device and an alkali flow control valve (not shown in the figure) can also be installed on the first branch pipe 911. The target value of the alkali flow rate entering the electrolytic cell is calculated according to the system load. Then, the opening of the alkali flow control valve is adjusted according to the difference between the actual flow rate of the first branch pipe 911 measured by the alkali flow detection device and the target value of the alkali flow rate, so that the alkali flow rate approaches the target value of the alkali flow rate.

[0033] Optionally, in some embodiments of this application, reference is made to Figure 2 The hydrogen production system also includes a circulating pump group 5, which includes a first circulating pump 51 and a second circulating pump 52. The alkali cooling device includes a first cooler 41 and a second cooler 42. The first cooler 41 and the second cooler 42 are arranged in parallel and each has a liquid inlet. The liquid inlet of the first circulating pump 51 is connected to the liquid outlet of the first hydrogen-side buffer tank 31 and the liquid outlet of the first oxygen-side buffer tank 32, respectively. The liquid outlet of the first circulating pump 51 is connected to the liquid inlet of the first cooler 41. The liquid inlet of the second circulating pump 52 is connected to the liquid outlet of the first hydrogen-side buffer tank 31 and the liquid outlet of the first oxygen-side buffer tank 32, respectively. The liquid outlet of the second circulating pump 52 is connected to the liquid inlet of the second cooler 42.

[0034] Specifically, the first circulating pump 51 and the second circulating pump 52 are arranged in parallel. The inlet of the first circulating pump 51 is connected to the outlet of the corresponding buffer tank, and the outlet of the first circulating pump is connected to the inlet of the first cooler 41. The inlet of the second circulating pump 52 is connected to the outlet of the corresponding buffer tank, and the outlet of the second circulating pump 52 is connected to the inlet of the second cooler 42. That is, they are connected in series between the corresponding buffer tank and the cooler, forming two series pipelines, and these two series pipelines are arranged in parallel. The parallel arrangement of the first cooler 41 and the second cooler 42 means that the inlet and outlet of the two coolers are independent of each other. In this way, a parallel redundant circulation link constituting a dual-pump dual-cooler is formed. When one series pipeline fails, the system can quickly switch to the other series pipeline to ensure the continuous supply of alkali solution and improve the stability of the system. Furthermore, the number of series pipelines can be set according to the system production load. When the system production load is high, the number of series pipelines can be increased; when the system production load is low, the number of series pipelines can be decreased to ensure compatibility and broaden the applicable scenarios of the alkali circulation system. Simultaneously, placing the circulation pump unit 5 between the buffer tank and the alkali cooling device, i.e., at the front end of the second connecting pipe 92, helps reduce interference from the circulation pump unit 5 to the pressure detection device on the second connecting pipe 92 and to the pressure control valve on the second branch pipe 912.

[0035] Optionally, in some embodiments of this application, the hydrogen production system further includes at least two gas purity detection devices; each group of gas-liquid separation devices 2 is connected to at least one gas purity detection device. In other words, at least one gas purity detection device is connected to a hydrogen-side separation device 21 and an oxygen-side separation device 22. The number of gas purity detection devices can be one, which can be connected to the hydrogen-side separation device 21 to detect the purity of the hydrogen separated by the hydrogen-side separation device 21, and can also be connected to the oxygen-side separation device 22 to detect the purity of the oxygen separated by the oxygen-side separation device 22. Alternatively, the number of gas purity detection devices can be two, with the two gas purity detection devices respectively connected to the hydrogen-side separation device 21 and the oxygen-side separation device 22.

[0036] The indicators for measuring gas purity include the detection of oxygen content mixed in hydrogen, hydrogen content mixed in oxygen, and the content of alkaline droplets and electrolyte residues carried in hydrogen or oxygen. In this embodiment, a gas purity detection device is preferably connected to the oxygen-side separation device 22, focusing on detecting the hydrogen content mixed in oxygen. This is because hydrogen permeation is more likely to occur on the oxygen side during water electrolysis for hydrogen production, leading to excessive hydrogen content in the oxygen and becoming a major cause of unqualified gas purity. Therefore, focusing on detecting the hydrogen content mixed in oxygen improves the accuracy of detecting unqualified gases and more efficiently ensures the gas production quality of the system.

[0037] The gas purity detection device can be a gas analyzer, using online real-time monitoring to continuously detect key component indicators of hydrogen and oxygen separated by the gas-liquid separator 2 to determine whether the gas purity is up to standard. It is understood that the hydrogen production system includes a control device for controlling the normal operation of the system, and the gas purity detection device is electrically connected to the control device and is under its unified control. In this embodiment, the gas purity detection device detects the purity of the gas separated by the gas-liquid separator 2. If the detected purity is up to standard, the gas can be directly used in subsequent processes. If the detected purity is below standard, the malfunctioning electrolyzer 1 can be quickly located and shut down.

[0038] Optionally, in some embodiments of this application, reference is made to Figure 1 The hydrogen production system also includes a hydrogen-side gas outlet pipe 71 and an oxygen-side gas outlet pipe 72; the gas outlet of each hydrogen-side separation device 21 is connected to the hydrogen-side gas outlet pipe 71, and the gas outlet of each oxygen-side separation device 22 is connected to the oxygen-side gas outlet pipe 72.

[0039] Specifically, the outlet of each hydrogen-side separator 21 is connected to the hydrogen-side outlet pipe 71 via a branch pipe. That is, the hydrogen-side outlet pipe 71 acts as a collection pipe, summarizing and outputting the hydrogen separated from each hydrogen-side separator 21. Similarly, the outlet of each oxygen-side separator 22 is connected to the oxygen-side outlet pipe 72 via a branch pipe. That is, the oxygen-side outlet pipe 72 acts as a collection pipe, summarizing and outputting the oxygen separated from each oxygen-side separator 22. Compared to the traditional single-pipe direct delivery structure, this significantly reduces the number of pipes required, facilitating the unified layout and management of gas collection pipelines and improving system space utilization.

[0040] In addition, the convergence design of the hydrogen-side gas outlet pipe 71 and the oxygen-side gas outlet pipe 72 can make the pressure at the gas outlet of each separation device more balanced, avoiding local pressure changes in the system due to fluctuations in the gas production rate of a single separation device, which is conducive to the stable delivery of gas.

[0041] Optionally, in some embodiments of this application, reference is made to Figure 1 The hydrogen production system also includes a hydrogen-side liquid outlet pipe 73 and an oxygen-side liquid outlet pipe 74; the hydrogen-side liquid outlet pipe 73 is connected to the first hydrogen-side buffer tank 31, and the oxygen-side liquid outlet pipe 74 is connected to the first oxygen-side buffer tank 32; the liquid outlet of each hydrogen-side separation device 21 is connected to the hydrogen-side liquid outlet pipe 73, and the liquid outlet of each oxygen-side separation device 22 is connected to the oxygen-side liquid outlet pipe 74.

[0042] Specifically, both the hydrogen-side outlet pipe 73 and the oxygen-side outlet pipe 74 can be made of corrosion-resistant pipes such as stainless steel. The hydrogen-side outlet pipe 73 is connected to the first hydrogen-side buffer tank 31, and the oxygen-side outlet pipe 74 is connected to the first oxygen-side buffer tank 32. The connection method can be a flange connection to facilitate later disassembly and maintenance. The hydrogen-side outlet pipe 73 acts as a collection pipe, collecting the alkaline solutions separated by each hydrogen-side separation device 21 into the first hydrogen-side buffer tank 31. The oxygen-side outlet pipe 74 acts as a collection pipe, collecting the alkaline solutions separated by each oxygen-side separation device 22 into the first oxygen-side buffer tank 32. Sealing rings can be installed at the connection points between each outlet pipe and the buffer tank to ensure the sealing of the connection and prevent leakage.

[0043] In this embodiment, the alkaline solutions separated by each hydrogen-side separator 21 and each oxygen-side separator 22 are collected into corresponding buffer tanks via a hydrogen-side liquid outlet pipe 73 and an oxygen-side liquid outlet pipe 74. This configuration requires only one inlet port on each buffer tank, avoiding excessive openings and reducing the possibility of liquid leakage or cross-contamination, thus further improving the safety of the hydrogen production system. When the number of electrolyzers 1 and gas-liquid separators 2 needs to be increased, only branch pipe interfaces need to be added to the existing hydrogen-side liquid outlet pipe 73 or oxygen-side liquid outlet pipe 74, without requiring secondary drilling modifications to the buffer tanks, thereby reducing the difficulty and cost of system expansion. Simultaneously, the fewer openings on the buffer tanks also simplify the manufacturing process and extend their service life.

[0044] Optionally, in some embodiments of this application, reference is made to Figure 3 The third schematic diagram of the hydrogen production system in the embodiment of this application is shown. The hydrogen production system also includes a hydrogen-side washing device 61 and an oxygen-side washing device 62; the hydrogen-side gas outlet pipe 71 is connected to the hydrogen-side washing device 61, and the oxygen-side gas outlet pipe 72 is connected to the oxygen-side washing device 62.

[0045] Specifically, the hydrogen-side scrubbing device 61 is used to scrub the hydrogen separated by the hydrogen-side separator 21 to remove the alkaline solution mixed in the hydrogen, and the oxygen-side scrubbing device 62 is used to scrub the oxygen separated by the oxygen-side separator 22 to remove the alkaline solution mixed in the oxygen. The hydrogen-side scrubbing device 61 and the oxygen-side scrubbing device 62, through sufficient contact between the scrubbing liquid (such as demineralized water, special scrubbing liquid, etc.) and the gas, can effectively remove residual trace impurities such as alkaline impurities from the gas, further improving the purity of the hydrogen and oxygen. Since the volume of qualified gas is usually greater than that of unqualified gas, different scrubbing devices can be used for scrubbing qualified and unqualified gas. For example, qualified gas can be scrubbing with higher efficiency and better effect, such as a bubble spray integrated scrubbing device, while unqualified gas can be scrubbing with a commonly used bubble scrubbing device or a spray scrubbing device.

[0046] Optionally, in some embodiments of this application, the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are each provided with a third liquid inlet; the third liquid inlet of the first hydrogen-side buffer tank 31 is connected to the liquid outlet of the hydrogen-side washing device 61, and the third liquid inlet of the first oxygen-side buffer tank 32 is connected to the liquid outlet of the oxygen-side washing device 62. In this way, the alkaline solution flowing out of the hydrogen-side washing device 61 and the oxygen-side washing device 62 can flow into the corresponding buffer tank, mixing the alkaline washing solution with the alkaline solution in the buffer tank. This helps maintain the stability of the alkaline solution concentration in the buffer tank, reduces the impact of concentration fluctuations on the electrolysis reaction efficiency, and ensures the stable operation of the system. Simultaneously, the flowing washing solution can also compensate for the reduction in the total amount of alkaline solution caused by evaporation and loss during electrolysis, thereby further ensuring the stable operation of the system.

[0047] Optionally, in some embodiments of this application, the hydrogen-side scrubbing device and / or oxygen-side scrubbing device includes a scrubbing tower 6; see reference Figure 4 The diagram illustrates a washing tower according to an embodiment of this application. The washing tower 6 includes a bubbling section 601, a spray section 602, a water supply pipe 611, and a first outlet pipe 621. The bubbling section 601 is located at the lower part of the washing tower 6 and is used to store washing liquid. A water supply port is provided on the side wall of the washing tower 6, and the water supply pipe 611 extends from the water supply port into the bubbling section 601. The spray section 602 is located at the upper part of the washing tower 6 and is equipped with nozzles. A liquid outlet is provided on the bottom wall of the washing tower 6, and the first outlet pipe 621 is connected to the liquid outlet of the washing tower 6. One end of the first outlet pipe 621 away from the liquid outlet of the washing tower 6 is connected to the nozzle. And / or, the washing tower 6 includes a second outlet pipe 622, which is connected to the liquid outlet of the washing tower 6, and one end of the second outlet pipe 622 away from the liquid outlet of the washing tower 6 is connected to a corresponding hydrogen-side buffer tank or oxygen-side buffer tank.

[0048] Specifically, in one embodiment of this invention, the scrubbing tower 6 is an integrated bubbling and spraying scrubbing tower, including a bubbling section 601 and a spraying section 602. The bubbling section 601 is located at the bottom of the scrubbing tower 6 and is used to store the scrubbing liquid, serving as the primary scrubbing zone. Gas enters from the air inlet at the bottom of the bubbling section 601 (e.g., air from the inlet at the bottom of the bubbling section 601). Figure 4 The gas (as shown in m) enters the washing tower 6 and is dispersed into microbubbles by aeration components such as porous aeration discs, allowing the gas to fully contact the washing liquid and remove large electrolyte droplets, soluble impurities, etc., thus achieving primary impurity removal. A spray section 602 is located at the top of the washing tower 6. The spray section 602 is equipped with nozzles, which can be high-pressure atomizing nozzles. There can be one or more nozzles; for example, multiple nozzles can be arranged in a uniform ring to ensure no dead angles in the spray coverage area and improve the washing effect of the gas.

[0049] In this embodiment, the gas first enters the bubbling section 601, where it undergoes a first wash by fully contacting the bubbles with the washing liquid, removing most of the large particulate impurities and soluble impurities. Subsequently, the gas continues to rise to the spraying section 602, where the washing liquid is sprayed onto the upper part of the washing tower 6 through nozzles to form a uniform water curtain. The water curtain contacts the gas in the opposite direction to achieve a second wash, further removing trace impurities and fine droplets from the gas. The synergy of the two washes significantly improves the removal rate of impurities in the gas, thereby greatly improving the gas purity.

[0050] The side wall of the washing tower 6 is provided with a water inlet, and a water supply pipe 611 extends from the water inlet into the bubbling section 601. The end of the water supply pipe 611 (e.g. Figure 4 As shown in n), the water supply pipe 611 extends into the bubbling section 601. The end of the water supply pipe 611 extends below the liquid surface of the washing liquid stored in the bubbling section 601. The sealing effect of the liquid prevents gas from flowing back into the external pipeline through the water supply pipe 611, which helps to maintain the stability of the liquid level in the bubbling section 601.

[0051] The bottom wall of the scrubbing tower 6 is equipped with a liquid outlet (such as...). Figure 4 As shown in q), the first liquid outlet pipe 621 is connected to the liquid outlet of the scrubbing tower 6. The end of the first liquid outlet pipe 621 away from the liquid outlet of the scrubbing tower 6 is connected to the nozzle of the spray section 602. This allows the scrubbing liquid flowing out of the liquid outlet to be sent back to the nozzle. The nozzle forms a water curtain again at the top of the scrubbing tower 6 to scrub the gas. The scrubbing liquid continues to flow down the scrubbing tower 6 into the bubbling section 601. In this way, the sealing effect of the liquid in the bubbling section 601 and the first liquid outlet pipe 621 prevents the gas from flowing back into the external water supply system through the nozzle, thereby avoiding danger.

[0052] In another embodiment of this invention, the scrubbing tower 6 includes a second outlet pipe 622, which is connected to the outlet of the scrubbing tower 6. One end of the second outlet pipe 622, away from the outlet of the scrubbing tower 6, is connected to a corresponding hydrogen-side buffer tank or oxygen-side buffer tank. With this configuration, the alkalinity of the scrubbing liquid, having captured impurities in the gas, increases. This liquid is then directly added to the corresponding hydrogen-side or oxygen-side buffer tank, mixing with the alkaline solution in the buffer tank. The alkaline solution is then replenished to the electrolytic cell 1 via the alkaline solution circulation system. This indirectly compensates for the alkaline solution consumed during the electrolysis process within the electrolytic cell 1, eliminating the need for replenishment of individual electrolytic cells 1. This avoids uneven local alkaline solution concentrations and ensures stable system operation. Meanwhile, in the existing technology, the washing liquid is added to the gas-liquid separation device and then the gas-liquid separation device is used to replenish the electrolytic cell. This can cause liquid level fluctuations and imbalances in the gas-liquid separation device due to the addition of washing liquid. The method in this embodiment can avoid liquid level imbalances in the gas-liquid separation device, thereby reducing the risk of hydrogen and oxygen gas cross-contamination.

[0053] It should be noted that the way the scrubbing tower 6 is connected to the corresponding hydrogen-side buffer tank or oxygen-side buffer tank through the second liquid outlet pipe 622 can be applied to scrubbing tower 6 including bubbling section 601 and spray section 602, and can also be applied to bubbling scrubbing towers or spray scrubbing towers in the prior art.

[0054] In another embodiment of this invention, the scrubbing tower 6 is an integrated bubbling and spraying scrubbing tower, including a bubbling section 601 and a spraying section 602. The bottom wall of the scrubbing tower 6 may have two liquid outlets, one connected to a first liquid outlet pipe 621 and the other connected to a second liquid outlet pipe 622. Alternatively, the bottom wall of the scrubbing tower 6 may have only one liquid outlet, which is connected to both the first liquid outlet pipe 621 and the second liquid outlet pipe 622 via a main pipe. Figure 4 The diagram shows a washing tower with only one outlet on its bottom wall. For example, a liquid pump 63 can be installed below the washing tower 6. The inlet of the liquid pump 63 is connected to the outlet of the washing tower 6, and the outlet of the liquid pump 63 is connected to the first outlet pipe 621 and the second outlet pipe 622, respectively. This allows the washing liquid flowing from the outlet to be pumped to the nozzle or the corresponding hydrogen-side buffer tank or oxygen-side buffer tank, overcoming the backflow resistance of the washing liquid and ensuring its smooth return.

[0055] Optionally, in some embodiments of this application, such as Figure 4As shown, the washing tower 6 also includes a first regulating valve 64, a second regulating valve 65, and a liquid level monitoring device 66; the first regulating valve 64 is connected to the first outlet pipe 621, the second regulating valve 65 is connected to the second outlet pipe 622, and the liquid level monitoring device 66 is located in the bubbling section 601 and is electrically connected to the first regulating valve 64 and the second regulating valve 65 respectively; the liquid level monitoring device 66 is used to monitor the liquid level of the washing liquid in the bubbling section 601 and control the valve opening of the first regulating valve 64 and the second regulating valve 65 according to the liquid level.

[0056] Specifically, the first regulating valve 64, the second regulating valve 65, and the liquid level monitoring device 66 are electrically connected to form an automatic liquid level control loop. The openings of the two regulating valves are complementary. When the liquid level monitoring device 66 detects that the liquid level of the washing liquid in the bubbling section 601 is too high, the opening of the first regulating valve 64 decreases, and the opening of the second regulating valve 65 increases. This reduces the amount of liquid flowing back to the spray section 602 of the washing tower 6 and increases the amount of liquid flowing from the washing tower 6 to the buffer tank, thereby gradually lowering the liquid level of the washing liquid in the bubbling section 601. When the liquid level monitoring device 66 detects that the liquid level of the washing liquid in the bubbling section 601 is too low, the opening of the first regulating valve 64 increases, and the opening of the second regulating valve 65 decreases. This increases the amount of liquid flowing back to the spray section 602 of the washing tower 6 and decreases the amount of liquid flowing from the washing tower 6 to the buffer tank, thereby gradually raising the liquid level of the washing liquid in the bubbling section 601. Therefore, by setting up an automatic liquid level control loop, it is beneficial to ensure that the liquid level of the washing liquid in the bubbling section 601 is within a reasonable range, thus ensuring the stable operation of the washing tower 6.

[0057] Optionally, in some embodiments of this application, such as Figure 4 As shown, the washing tower 6 also includes a packing section 603, which is filled with wire mesh; the bubbling section 601, the packing section 603, and the spraying section 602 are arranged sequentially from bottom to top along the height direction of the washing tower 6.

[0058] Specifically, the packing section 603 is located between the bubbling section 601 and the spraying section 602. The packing section 603 is filled with wire mesh packing, which can be packed in a regular or irregular manner, enabling the washing liquid to form a uniform liquid film on the surface of the packing. The packing section 603 receives the rising gas from the bubbling section 601 and the falling washing liquid from the spraying section 602. The gas and liquid film make full counter-current contact on the surface of the wire mesh packing, utilizing the gas-liquid mass transfer effect to efficiently capture residual fine particulate alkaline mist, trace electrolyte molecules, and other impurities in the gas, thus achieving secondary washing of the gas.

[0059] In some embodiments, the top of the scrubbing tower 6 is further provided with a liquid collection section 604, which is equipped with a collection filter element that can capture free water in the gas, so that small droplets are retained by the filter element, and the gas passes through to complete gas-liquid separation, thereby further improving the purity of the gas, and finally sending the high-purity gas out through the gas outlet pipe.

[0060] Thus, in this embodiment, the scrubbing tower 6 achieves the first washing of the gas through the bubbling section 601, where the bubbles fully contact the scrubbing liquid, initially removing large particulate impurities, coarse droplets, and some soluble impurities from the gas. The gas then continues to rise to the packing section 603, where the gas and liquid film make full counter-current contact on the surface of the wire mesh packing, achieving the second washing of the gas and efficiently capturing residual fine particulate alkaline mist, electrolyte molecules, and other trace impurities. The gas then continues to rise to the spray section 602, where a water curtain formed by spraying nozzles makes counter-current contact with the gas, achieving the third washing of the gas and further removing trace impurities and fine droplets. Finally, the gas continues to rise to the liquid collection section 604, where free water in the gas is captured, achieving the fourth washing of the gas, improving gas purity, and finally, the high-purity gas is sent out through the outlet pipe at the top of the scrubbing tower 6.

[0061] Optionally, in some embodiments of this application, such as Figure 4 As shown, the washing tower 6 also includes a first pressure monitoring device 67 and a second pressure monitoring device 68; the first pressure monitoring device 67 is connected to the water supply pipe 611 and is used to monitor the pressure inside the water supply pipe 611; the second pressure monitoring device 68 is connected to the top of the washing tower 6 and is used to monitor the pressure at the top of the washing tower 6.

[0062] Specifically, the first pressure monitoring device 67 and the second pressure monitoring device 68 are electrically connected to form a pressure interlock protection circuit. The first pressure monitoring device 67 is used to monitor the pressure inside the water supply pipe 611, and the second pressure monitoring device 68 is used to monitor the pressure at the top of the scrubbing tower 6. When the pressure inside the water supply pipe 611 is higher than the pressure at the top of the scrubbing tower 6, and the difference between the two is not less than a preset value, the water supply pipe 611 is opened to replenish water to the scrubbing tower 6. This configuration effectively improves the safety of the scrubbing tower 6 and prevents gas backflow.

[0063] Furthermore, the water supply pipe 611 can also be equipped with a flow regulation loop, and the flow rate setpoint can be flexibly set according to process requirements. In this way, the washing liquid can be continuously input at the set flow rate, and a continuous water supply process can be adopted. The water inlet flow rate can be automatically adjusted and controlled according to the operating load signal, so that the water supply can be automatically adapted to the production load, thereby improving the stability of the washing tower 6.

[0064] Optionally, in some embodiments of this application, reference is made to Figure 3The hydrogen production system also includes a hydrogen-side gas cooling device 81 and an oxygen-side gas cooling device 82; the hydrogen-side gas outlet pipe 71 is connected to the hydrogen-side gas cooling device 81, and the oxygen-side gas outlet pipe 72 is connected to the oxygen-side gas cooling device 82; the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are also provided with a fourth liquid inlet; the fourth liquid inlet of the first hydrogen-side buffer tank 31 is connected to the liquid outlet of the hydrogen-side gas cooling device 81, and the fourth liquid inlet of the first oxygen-side buffer tank 32 is connected to the liquid outlet of the oxygen-side gas cooling device 82.

[0065] Specifically, the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are each equipped with a fourth liquid inlet. The fourth liquid inlet of the first hydrogen-side buffer tank 31 is connected to the liquid outlet of the hydrogen-side gas cooling device 81, and the fourth liquid inlet of the first oxygen-side buffer tank 32 is connected to the liquid outlet of the oxygen-side gas cooling device 82. The hydrogen-side gas cooling device 81 is located downstream of the hydrogen-side separation device 21, and can be located upstream or downstream of the hydrogen-side washing device 61. The oxygen-side gas cooling device 82 is located downstream of the oxygen-side separation device 22, and can be located upstream or downstream of the oxygen-side washing device 62. The condensate generated during the cooling process of the hydrogen-side gas cooling device 81 and the oxygen-side gas cooling device 82 can flow directionally into the corresponding buffer tank through the fourth liquid inlet, thus adding another water replenishment path for the corresponding buffer tank and further improving the recovery rate of the alkali solution.

[0066] Furthermore, such as Figure 3 As shown, the hydrogen production system also includes a hydrogen-side gas-liquid separator 83 and an oxygen-side gas-liquid separator 84. The first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 are each equipped with a fifth liquid inlet. The fifth liquid inlet of the first hydrogen-side buffer tank 31 is connected to the liquid outlet of the hydrogen-side gas-liquid separator 83, and the fifth liquid inlet of the first oxygen-side buffer tank 32 is connected to the liquid outlet of the oxygen-side gas-liquid separator 84. The gas inlet of the hydrogen-side gas-liquid separator 83 is connected to the gas outlet of the hydrogen-side gas cooling device 81. The hydrogen-side gas-liquid separator 83 is used to perform gas-liquid separation on the hydrogen cooled by the hydrogen-side gas cooling device 81 to improve the purity of the hydrogen product. The gas inlet of the oxygen-side gas-liquid separator 84 is connected to the gas outlet of the oxygen-side gas cooling device 82. The oxygen-side gas-liquid separator 84 is used to perform gas-liquid separation on the oxygen cooled by the oxygen-side gas cooling device 82. The condensate separated by the hydrogen and oxygen side gas-liquid separators can flow into the corresponding buffer tank through the fifth inlet, thus adding another water replenishment path for the corresponding buffer tank and further improving the recovery rate of the alkali solution.

[0067] Optionally, in some embodiments of this application, the opening of the connecting pipe connected to at least one liquid inlet on the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 does not exceed the inner wall of the corresponding first hydrogen-side buffer tank 31 or first oxygen-side buffer tank 32. The liquid inlets on the first hydrogen-side buffer tank 31 and the first oxygen-side buffer tank 32 may include a first liquid inlet a, a second liquid inlet b, a third liquid inlet, and a fourth liquid inlet. This means that the connecting pipe does not extend into the receiving cavity of the buffer tank. For example, the opening of the connecting pipe can be connected to the outer wall of the buffer tank, with the edge of the opening connected to the outer wall flange around the corresponding liquid inlet, thereby achieving communication between the connecting pipe and the corresponding liquid inlet. Alternatively, the opening of the connecting pipe can be housed within the corresponding liquid inlet, with the end of the opening located between the inner and outer walls of the buffer tank, or flush with the inner wall of the buffer tank, thus also achieving communication between the connecting pipe and the corresponding liquid inlet. This configuration allows the hydrogen or oxygen released from the alkali solution in the buffer tank to form natural convection due to the density difference, enabling the hydrogen or oxygen to flow back to the corresponding device through the connecting pipe. It also helps maintain the normal transport and circulation of the alkali solution in the buffer tank, further improving the stability of the alkali solution circulation system.

[0068] Optionally, in some embodiments of this application, the hydrogen-side separation device 21 and the first hydrogen-side buffer tank 31 have the same pressure, and the oxygen-side separation device 22 and the first oxygen-side buffer tank 32 have the same pressure. This helps to maintain a constant pressure during the operation of the hydrogen production system and ensures the stable operation of the system.

[0069] Secondly, embodiments of this application also provide a method for producing hydrogen by electrolysis of water using a hydrogen production system. The hydrogen production system includes at least two electrolyzers 1, at least two sets of gas-liquid separation devices 2, at least two gas purity detection devices, a first gas processing system, and a second gas processing system. The gas-liquid separation device 2 includes a hydrogen-side separation device 21 and an oxygen-side separation device 22. Each electrolyzer 1 is connected to a hydrogen-side separation device 21 and an oxygen-side separation device 22. Each set of gas-liquid separation devices 2 is connected to at least one gas purity detection device.

[0070] The methods for producing hydrogen through water electrolysis using a hydrogen production system include: Step S1: Use a gas purity detection device to detect the purity of the gas separated by the gas-liquid separator 2.

[0071] In this step, each gas-liquid separation device 2 is connected to at least one gas purity detection device. In other words, at least one gas purity detection device is connected to each hydrogen-side separation device 21 and each oxygen-side separation device 22. The number of gas purity detection devices can be one, connected to the hydrogen-side separation device 21 to detect the purity of the hydrogen separated by the hydrogen-side separation device 21, and also connected to the oxygen-side separation device 22 to detect the purity of the oxygen separated by the oxygen-side separation device 22. Alternatively, the number of gas purity detection devices can be two, connected to the hydrogen-side separation device 21 and the oxygen-side separation device 22 respectively. The gas purity detection device can be a gas analyzer, using online real-time monitoring to continuously detect the composition indicators of the hydrogen separated by the hydrogen-side separation device 21 and the oxygen separated by the oxygen-side separation device 22 to determine whether the gas purity is qualified.

[0072] Step S2: When the gas purity detection device detects that the gas purity is qualified, the gas separated by the gas-liquid separator 2 is controlled to flow to the first gas processing system; or, when the gas purity detection device detects that the gas purity is unqualified, the gas separated by the gas-liquid separator 2 is controlled to flow to the second gas processing system.

[0073] In this step, the first gas processing system can be considered as the processing system for qualified gas, and the second gas processing system can be considered as the processing system for unqualified gas. The purity of the separated hydrogen and oxygen is detected by a gas purity detection device. If the purity of the separated gas is qualified, the gas flow is controlled to the first gas processing system for further processing; if the purity of the separated gas is unqualified, the gas flow is controlled to the second gas processing system for further processing. This effectively prevents cross-contamination between hydrogen and oxygen gases produced by multiple electrolyzers during gas processing, keeping the gas concentration within a safe range and ensuring system safety. Simultaneously, having qualified and unqualified gases enter different gas processing systems for further processing helps avoid the waste of water and alkali carried by unqualified gas emitted in previous large-scale hydrogen production systems, controlling the cost of raw material water and alkali, and avoiding environmental pollution problems caused by unqualified gas emissions. Furthermore, the separation of qualified and unqualified gases prevents unqualified gas from contaminating qualified gas when processing gas from multiple electrolyzers, ensuring the gas production quality of the system.

[0074] Furthermore, the hydrogen-side separation device 21 and the oxygen-side separation device 22 may each include a main outlet pipe. Each main outlet pipe includes a first outlet and a second outlet. The first outlet is connected to the first gas processing system, and the second outlet is connected to the second gas processing system. The first outlet is equivalent to a qualified gas outlet, and the second outlet is equivalent to a non-qualified gas outlet. The gas purity detection device can be connected to the main outlet pipe or to other outlets of the hydrogen-side separation device 21 or the oxygen-side separation device 22. The gas purity detection device can detect the purity of the gas in the hydrogen-side separation device 21 and / or the oxygen-side separation device 22, that is, it can indirectly detect the purity of the gas in the main outlet pipe. The gas separated by the hydrogen-side separation device 21 and the oxygen-side separation device 22 flows out from the main outlet pipe. When the gas purity in the main outlet pipe is detected to be qualified, the gas is controlled to flow out from the first outlet. When the gas purity in the main outlet pipe is detected to be unqualified, the gas is controlled to flow out from the second outlet. The first outlet is connected to the first gas processing system to form a qualified gas path, directly delivering qualified gas to the first gas processing system. The second outlet is connected to the second gas processing system to form a non-qualified gas path, directly delivering non-qualified gas to the second gas processing system, thus forming an independent dual-path structure.

[0075] A first control valve can be installed on the pipeline between the first gas outlet and the first gas processing system, and a second control valve can be installed on the pipeline between the second gas outlet and the second gas processing system. Both control valves are linked to the signal from the gas purity detection device and are controlled by the hydrogen production system's control device. This allows for rapid response based on the gas's purity status, controlling the corresponding gas path opening and closing. When the gas purity detection device detects that the gas purity is within acceptable limits, the first control valve opens simultaneously while the second control valve remains closed, delivering the acceptable gas to the first gas processing system. Conversely, when the gas purity detection device detects that the gas purity is insufficient, the second control valve opens simultaneously while the first control valve remains closed, delivering the unacceptable gas to the second gas processing system. Therefore, this embodiment employs a dual-outlet design with independent gas path connections to the control valves. Relying on the linkage signal between the gas purity detection device and the control valves, rapid separation of acceptable and unacceptable gas can be achieved, improving separation efficiency. Simultaneously, the independent gas path delivery of acceptable and unacceptable gas structurally prevents contamination of acceptable gas by unacceptable gas, further ensuring the system's gas production quality.

[0076] Optionally, in some embodiments of this application, the first gas processing system includes a first gas cooling device and a first gas scrubbing device; the second gas processing system includes a second gas scrubbing device and a second gas cooling device. Step S2 specifically includes: When the gas purity detection device detects that the gas purity is qualified, the gas separated by the gas-liquid separation device 2 is controlled to pass through the first gas cooling device and the first gas washing device in sequence for processing; or, when the gas purity detection device detects that the gas purity is unqualified, the gas separated by the gas-liquid separation device 2 is controlled to pass through the second gas washing device and the second gas cooling device in sequence for processing.

[0077] In this step, the first gas treatment system employs a cooling-then-washing approach to process the qualified gas. This is because the qualified gas in the hydrogen production system is the main product gas during continuous system operation, and its volume is large. Therefore, the first gas cooling device first cools down a large amount of qualified gas, causing most of the moisture to condense and precipitate, thus reducing the processing load of the subsequent washing stage. The first gas washing device further removes residual trace amounts of electrolyte droplets, soluble impurities, and uncondensed moisture from the gas. This improves washing and purification efficiency, maximizes the removal of alkaline mist carried by the qualified gas, reduces the amount of washing liquid stored in the washing device, and ensures the system's stability and economy under large volume operating conditions.

[0078] The second gas treatment system uses a process of washing first and then cooling to treat substandard gas. This is because the volume of substandard gas is usually smaller than that of qualified gas. Therefore, the substandard gas is first thoroughly purified by the second gas washing device, which can directly capture and remove most of the liquid impurities, reduce the operating energy consumption of the cooling equipment and the consumption of cooling water medium, and extend the service life of the second gas cooling device.

[0079] Both the first and second gas processing systems process hydrogen and oxygen separately. The first gas processing system includes a first hydrogen processing system and a first oxygen processing system, and the second gas processing system includes a second hydrogen processing system and a second oxygen processing system. The first hydrogen processing system includes a first hydrogen cooling device and a first hydrogen scrubbing device, and the first oxygen processing system includes a first oxygen cooling device and a first oxygen scrubbing device. The second hydrogen processing system includes a second hydrogen scrubbing device and a second hydrogen cooling device, and the second oxygen processing system includes a second oxygen scrubbing device and a second oxygen cooling device.

[0080] Optionally, in some embodiments of this application, the first gas washing device includes a bubbling section and a spraying section, and the gas is washed sequentially through the bubbling section and the spraying section.

[0081] In this step, the gas first enters the bubbling section, where it undergoes a first wash by fully contacting the bubbles with the washing liquid, removing most of the large particles and soluble impurities. The gas then continues to rise to the spraying section, where the washing liquid is sprayed through nozzles onto the upper part of the first gas washing device to form a uniform water curtain. The water curtain contacts the gas in the opposite direction, achieving a second wash to further remove trace impurities and fine droplets from the gas. The synergy of the two washes significantly improves the removal rate of impurities in the gas, thereby greatly improving the gas purity.

[0082] Furthermore, the first gas scrubbing device may also include a packing section located between the bubbling section and the spraying section. The packing section is filled with wire mesh packing, which enables the washing liquid to form a uniform liquid film on the surface of the packing. The gas sequentially passes through the bubbling section, the packing section, and the spraying section for scrubbing. The packing section receives the gas rising from the bubbling section and the washing liquid falling from the spraying section. The gas and the liquid film make full counter-current contact on the surface of the wire mesh packing, utilizing the gas-liquid mass transfer effect to efficiently capture residual fine particulate alkaline mist, trace electrolyte molecules, and other impurities in the gas, thus achieving a second scrubbing of the gas.

[0083] Specifically, the first gas scrubbing device can be the aforementioned scrubbing tower 6, and has the technical effects of the aforementioned scrubbing tower 6, which will not be elaborated here.

[0084] Optionally, in some embodiments of this application, the hydrogen production system further includes a first alkali buffer tank and a second alkali buffer tank; the method further includes: Step S3: Transport the alkaline solution separated by all gas-liquid separation devices 2 and the first gas processing system to the first alkaline solution buffer tank; transport the alkaline solution separated by the second gas processing system to the second alkaline solution buffer tank.

[0085] In this step, since the first gas treatment system processes qualified gas, the concentration of the separated alkali solution can be kept at a relatively stable state. However, the second gas treatment system processes unqualified gas, so the concentration of the separated alkali solution may fluctuate greatly. Therefore, in this embodiment, the alkali solution separated by two or more gas-liquid separation devices 2 and the first gas treatment system flows into the first alkali solution buffer tank, and the alkali solution separated by the second gas treatment system flows into the second alkali solution buffer tank, so as to achieve independent separation of alkali solution and help maintain the stable reaction of the electrolytic cell.

[0086] Specifically, the first alkali buffer tank includes the aforementioned hydrogen-side buffer tank and oxygen-side buffer tank. The hydrogen-side buffer tank is connected to the hydrogen-side separation device and is used to store the alkali solution separated by the hydrogen-side separation device. The oxygen-side alkali buffer tank is connected to the oxygen-side separation device and is used to store the alkali solution separated by the oxygen-side separation device. Simultaneously, the hydrogen-side alkali buffer tank is also connected to the first hydrogen-side washing device and the first hydrogen-side cooling device in the first gas processing system and is used to store the liquid separated by the first hydrogen-side washing device and the first hydrogen-side cooling device. The oxygen-side alkali buffer tank is also connected to the first oxygen-side washing device and the first oxygen-side cooling device in the first gas processing system and is used to store the liquid separated by the first oxygen-side washing device and the first oxygen-side cooling device. The second alkali buffer tank includes the aforementioned hydrogen-side buffer tank and oxygen-side buffer tank. The connection method between the second alkali buffer tank and the second gas processing system is the same as the connection method between the first alkali buffer tank and the first gas processing system, and will not be repeated here.

[0087] Optionally, in some embodiments of this application, before step S1, the method further includes: Step S4: Start the electrolytic cell and control the gas flow of the gas-liquid separation device 2 to the second gas processing system.

[0088] In this step, the second gas treatment system can also serve as a buffer system for parallel operation of the electrolytic cells. After the electrolytic cells are started, the gas flow of the gas-liquid separation device 2 is first controlled to the second gas treatment system. The second gas treatment system pressurizes the electrolytic cells that are shut down. When the pressure of the electrolytic cells is consistent with the pressure of the first gas treatment system, and the purity of the gas after electrolysis and separation is qualified by the gas purity detection device, the gas produced by the electrolytic cells is then connected to the first gas treatment system and enters normal operation. In this way, the gas preparation yield can be further guaranteed.

[0089] It should be understood that the phrase "some embodiments" throughout the specification means that a particular feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0090] Finally, it should be noted that the above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hydrogen production system, characterized in that, It includes at least two electrolyzers, at least two sets of gas-liquid separation devices, at least one hydrogen-side buffer tank and at least one oxygen-side buffer tank; The number of electrolytic cells is the same as the number of gas-liquid separation devices. Each gas-liquid separation device includes a hydrogen-side separation device and an oxygen-side separation device. Each electrolytic cell is connected to one hydrogen-side separation device and one oxygen-side separation device. The hydrogen-side buffer tank includes a first hydrogen-side buffer tank, and the oxygen-side buffer tank includes a first oxygen-side buffer tank. The first hydrogen-side buffer tank and the first oxygen-side buffer tank are respectively provided with a first liquid inlet. The liquid outlet of each hydrogen-side separation device is connected to the first liquid inlet of the first hydrogen-side buffer tank, and the liquid outlet of each oxygen-side separation device is connected to the first liquid inlet of the first oxygen-side buffer tank. The number of hydrogen-side separation devices is greater than the number of hydrogen-side buffer tanks, and the number of oxygen-side separation devices is greater than the number of oxygen-side buffer tanks.

2. The hydrogen production system according to claim 1, characterized in that, The number of hydrogen-side buffer tanks is at least two, and all the hydrogen-side buffer tanks are connected in series. And / or, the number of oxygen-side buffer tanks is at least two, and all of the oxygen-side buffer tanks are connected in series.

3. The hydrogen production system according to claim 1, characterized in that, It also includes an alkaline cooling device and a first connecting pipe, and the first hydrogen-side buffer tank and the first oxygen-side buffer tank are respectively provided with a second liquid inlet. The alkali cooling device includes an inlet end and an outlet end communicating with its internal cooling channel. The inlet end is connected to the outlet of the first hydrogen-side buffer tank and the outlet of the first oxygen-side buffer tank, respectively. The outlet end is connected to one end of the first connecting pipe. The other end of the first connecting pipe branches to form a first branch pipe and a second branch pipe. The first branch pipe is connected to the electrolytic cell, and the second branch pipe is connected to the second inlet of the first hydrogen-side buffer tank and the second inlet of the first oxygen-side buffer tank, respectively.

4. The hydrogen production system according to claim 3, characterized in that, A pressure control valve is installed on the second branch pipe.

5. The hydrogen production system according to claim 3, characterized in that, It also includes a circulating pump set, which includes a first circulating pump and a second circulating pump, and the alkali cooling device includes a first cooler and a second cooler; The first cooler and the second cooler are connected in parallel and each has a liquid inlet end; The inlet of the first circulating pump is connected to the outlet of the first hydrogen-side buffer tank and the outlet of the first oxygen-side buffer tank, respectively, and the outlet of the first circulating pump is connected to the inlet of the first cooler. The inlet of the second circulation pump is connected to the outlet of the first hydrogen-side buffer tank and the outlet of the first oxygen-side buffer tank, respectively, and the outlet of the second circulation pump is connected to the inlet of the second cooler.

6. The hydrogen production system according to claim 1 or 2, characterized in that, It also includes at least two gas purity detection devices; each gas-liquid separation device is connected to at least one of the gas purity detection devices.

7. The hydrogen production system according to claim 1, characterized in that, It also includes hydrogen-side outlet pipes and oxygen-side outlet pipes; The outlet of each hydrogen-side separation device is connected to the hydrogen-side outlet pipe, and the outlet of each oxygen-side separation device is connected to the oxygen-side outlet pipe.

8. The hydrogen production system according to claim 7, characterized in that, It also includes hydrogen-side scrubbing units and oxygen-side scrubbing units; The hydrogen-side outlet pipe is connected to the hydrogen-side scrubbing device, and the oxygen-side outlet pipe is connected to the oxygen-side scrubbing device.

9. The hydrogen production system according to claim 8, characterized in that, The first hydrogen-side buffer tank and the first oxygen-side buffer tank are each provided with a third liquid inlet; the third liquid inlet of the first hydrogen-side buffer tank is connected to the liquid outlet of the hydrogen-side washing device, and the third liquid inlet of the first oxygen-side buffer tank is connected to the liquid outlet of the oxygen-side washing device.

10. The hydrogen production system according to claim 8, characterized in that, The hydrogen-side scrubbing device and / or the oxygen-side scrubbing device includes a scrubbing tower; The washing tower includes a bubbling section, a spraying section, a water supply pipe, and a first liquid outlet pipe. The bubbling section is located at the bottom of the washing tower and is used to store washing liquid. A water supply port is provided on the side wall of the washing tower, and the water supply pipe extends from the water supply port into the bubbling section. The spraying section is located at the top of the washing tower and is equipped with spray nozzles. A liquid outlet is provided on the bottom wall of the washing tower, and the first liquid outlet pipe is connected to the liquid outlet of the washing tower. The end of the first liquid outlet pipe away from the liquid outlet of the washing tower is connected to the spray nozzle. And / or, the scrubbing tower includes a second outlet pipe, which is connected to the outlet of the scrubbing tower, and one end of the second outlet pipe away from the outlet of the scrubbing tower is connected to the corresponding hydrogen-side buffer tank or the oxygen-side buffer tank.

11. The hydrogen production system according to claim 10, characterized in that, The scrubbing tower also includes a first regulating valve, a second regulating valve, and a liquid level monitoring device; The first regulating valve is connected to the first outlet pipe, the second regulating valve is connected to the second outlet pipe, and the liquid level monitoring device is located in the bubbling section and is electrically connected to the first regulating valve and the second regulating valve respectively. The liquid level monitoring device is used to monitor the liquid level of the washing liquid in the bubbling section, and to control the valve opening of the first regulating valve and the second regulating valve according to the liquid level.

12. The hydrogen production system according to claim 10, characterized in that, The scrubbing tower also includes a packing section filled with wire mesh; The bubbling section, the packing section, and the spraying section are arranged sequentially from bottom to top along the height direction of the washing tower.

13. The hydrogen production system according to any one of claims 10 to 12, characterized in that, The scrubbing tower also includes a first pressure monitoring device and a second pressure monitoring device; The first pressure monitoring device is connected to the water supply pipe and is used to monitor the pressure inside the water supply pipe; The second pressure monitoring device is connected to the top of the washing tower and is used to monitor the pressure at the top of the washing tower.

14. The hydrogen production system according to claim 7, characterized in that, It also includes hydrogen-side gas cooling devices and oxygen-side gas cooling devices; The hydrogen-side outlet pipe is connected to the hydrogen-side gas cooling device, and the oxygen-side outlet pipe is connected to the oxygen-side gas cooling device. The first hydrogen-side buffer tank and the first oxygen-side buffer tank are each provided with a fourth liquid inlet; the fourth liquid inlet of the first hydrogen-side buffer tank is connected to the liquid outlet of the hydrogen-side gas cooling device, and the fourth liquid inlet of the first oxygen-side buffer tank is connected to the liquid outlet of the oxygen-side gas cooling device.

15. The hydrogen production system according to any one of claims 1, 3, 9, and 14, characterized in that, The opening of the connecting pipe connected to at least one inlet on the first hydrogen-side buffer tank and the first oxygen-side buffer tank does not exceed the inner wall of the corresponding hydrogen-side buffer tank or oxygen-side buffer tank.

16. The hydrogen production system according to claim 1, characterized in that, The hydrogen-side separation device and the first hydrogen-side buffer tank have the same pressure, and the oxygen-side separation device and the first oxygen-side buffer tank have the same pressure.

17. A method for producing hydrogen by electrolysis of water using a hydrogen production system, characterized in that, The hydrogen production system includes at least two electrolyzers, at least two sets of gas-liquid separation devices, at least two gas purity detection devices, a first gas processing system, and a second gas processing system; the gas-liquid separation device includes a hydrogen-side separation device and an oxygen-side separation device, and each electrolyzer is connected to one hydrogen-side separation device and one oxygen-side separation device. Each group of gas-liquid separation devices is connected to at least one of the gas purity detection devices; The method for producing hydrogen by electrolysis of water using the hydrogen production system includes: Step S1: Use the gas purity detection device to detect the purity of the gas separated by the gas-liquid separator; Step S2: When the gas purity detection device detects that the gas purity is qualified, the gas separated by the gas-liquid separation device is controlled to flow to the first gas processing system; or, when the gas purity detection device detects that the gas purity is unqualified, the gas separated by the gas-liquid separation device is controlled to flow to the second gas processing system.

18. The method according to claim 17, characterized in that, The first gas processing system includes a first gas cooling device and a first gas scrubbing device; the second gas processing system includes a second gas scrubbing device and a second gas cooling device. Step S2 specifically includes: When the gas purity detection device detects that the gas purity is qualified, the gas separated by the gas-liquid separation device is controlled to pass through the first gas cooling device and the first gas washing device in sequence for processing. Alternatively, when the gas purity detection device detects that the gas purity is unqualified, the gas separated by the gas-liquid separation device is controlled to pass through the second gas washing device and the second gas cooling device in sequence for processing.

19. The method according to claim 17, characterized in that, The first gas washing device includes a bubbling section and a spraying section, and the gas is washed sequentially through the bubbling section and the spraying section.

20. The method according to claim 17, characterized in that, The hydrogen production system further includes a first alkaline buffer tank and a second alkaline buffer tank; the method further includes: Step S3: Transport the alkaline solution separated by all the gas-liquid separation devices and the first gas processing system to the first alkaline solution buffer tank; transport the alkaline solution separated by the second gas processing system to the second alkaline solution buffer tank.

21. The method according to claim 17, characterized in that, Prior to step S1, the method further includes: Step S4: Start the electrolytic cell and control the gas flow of the gas-liquid separation device to the second gas processing system.

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