Hydrogen production device and hydrogen production system

Abstract

Disclosed are a hydrogen production device and a hydrogen production system. The hydrogen production device comprises an electrolyzer and a plurality of connecting pipes; the electrolyzer is used for outputting a gas to be treated; each of the plurality of connecting pipes is connected to the electrolyzer and is used for inputting said gas conveyed by the electrolyzer; at least one of the plurality of connecting pipes is provided with a cleaning filtration device; each of the cleaning filtration devices comprises a filter, in which an upper chamber and a lower chamber are provided, the filter being used for performing pre-separation treatment and filtration treatment on said gas that enters via the lower chamber, and then discharging same via the upper chamber. The present disclosure is used for performing pre-separation treatment and filtration treatment on gases to be treated, reduces the adverse effects of various metallic and non-metallic solid impurities on electrolytic chemical reactions in electrolyzers, electrical instruments and container corrosion, optimizes gas purity, and improvs the operation reliability and safety of hydrogen production systems.

Description

Hydrogen production equipment and hydrogen production system

[0001] This disclosure claims priority to Chinese Patent Application No. 2024116974318, filed on November 22, 2024, entitled "Hydrogen Production Apparatus and Hydrogen Production System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to a hydrogen production apparatus and a hydrogen production system. Background Technology

[0003] In related technologies, after an electrolyzer has been running for a period of time, the deposition of impurities will not only affect the hydrogen purification process, damage the hydrogen production equipment, affect the service life of the equipment and the hydrogen production effect, but also cause problems such as unqualified oxygen in hydrogen and unqualified hydrogen in oxygen, affecting the reliability and safety of the hydrogen production equipment. Summary of the Invention

[0004] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0005] This disclosure proposes a hydrogen production apparatus, comprising:

[0006] An electrolytic cell is used to output the gas to be processed.

[0007] Multiple connecting pipelines, each of which is connected to the electrolytic cell, for conveying the gas to be processed output from the electrolytic cell;

[0008] At least one of the multiple connecting pipelines is equipped with a clean filtration device. Each clean filtration device includes a filter, which has an upper chamber and a lower chamber. The filter is used to pre-separate and filter the gas to be treated that enters through the lower chamber, and then discharge it through the upper chamber.

[0009] In one embodiment, the filter includes a filter element and a separator. The filter element divides the filter into an upper chamber and a lower chamber. The lower chamber has a first input channel, and the upper chamber has a gas output channel. The separator is positioned in the lower chamber corresponding to the first input channel. The separator is used to pre-separate the gas to be treated that enters the lower chamber through the first input channel. The filter element is used to filter the gas that has undergone pre-separation and discharge it through the gas output channel.

[0010] In one embodiment, the upper chamber is provided with a first interface, and the lower chamber is provided with a second interface; the clean filtration device further includes a differential pressure detection component and a control circuit, the first detection end of the differential pressure detection component is connected to the first interface, the second detection end of the differential pressure detection component is connected to the second interface, and the differential pressure detection component is used to detect the internal pressure difference between the upper chamber and the lower chamber;

[0011] The control circuit is connected to the differential pressure detection component and is used to control the first input channel and the gas output channel of the filter to open when the internal differential pressure is not greater than a preset first differential pressure, so that the filter switches to the working state.

[0012] In one embodiment, a baffle is provided inside the filter at a position corresponding to the second interface, and the baffle is oriented toward the second interface.

[0013] In one embodiment, the clean filtration device further includes a liquid level detection component connected to the filter for detecting the internal liquid level of the filter;

[0014] The control circuit is connected to the liquid level detection component and is used to control the first input channel and the gas output channel of the filter to close when the internal pressure difference is not less than a preset second pressure difference and the liquid level is not higher than a preset first liquid level value, so that the filter switches to standby state.

[0015] In one embodiment, the liquid level detection component is used to output a low liquid level alarm signal to the control circuit when the liquid level in the filter is not higher than a preset low liquid level value; and / or, the liquid level detection component is used to output a high liquid level alarm signal to the control circuit when the liquid level in the filter is not lower than a preset high liquid level value.

[0016] In one embodiment, the filter element is either a metal filter element or a non-metal filter element.

[0017] In one embodiment, the clean filtration device further includes a recycling tank, and the filter has a recycling channel at its bottom, through which the filter is connected to the recycling tank.

[0018] In one embodiment, the upper chamber of the filter is provided with a first channel, and the filter is provided with a filter element; the clean filtration device further includes a control circuit, in which the filter element is a metal filter element and the filter is in standby state, the control circuit controls the recovery channel to open, controls the first channel to open at preset time intervals, and controls the input of fluid with a first target pressure to the filter element after each opening of the first channel.

[0019] In one embodiment, the upper chamber of the filter is provided with a first channel, and the filter is provided with a filter element; the clean filtration device further includes a control circuit, which controls the opening of the recycling channel and the first channel when the filter element is a non-metallic filter element and the filter is in standby state.

[0020] In one embodiment, the filter includes a lower end cap disposed at the bottom of the lower chamber, and the recovery channel is disposed at the lower end cap.

[0021] In one embodiment, the hydrogen production device includes a separation device, a scrubber, and a cooler. The upper chamber is provided with a gas-liquid output channel communicating with the separation device. The separation device is provided with a first output channel and a second output channel. The separation device is connected to the scrubber through the first output channel and to the cooler through the second output channel. The cooler is used to cool the electrolyte delivered by the separation device.

[0022] In addition, this disclosure also proposes a hydrogen production system, which includes a control circuit and the hydrogen production device described above.

[0023] After reading and understanding the accompanying diagrams and detailed descriptions, the other aspects can be understood.

[0024] One or more technical solutions proposed in this disclosure have at least the following technical effects: By performing pre-separation and filtration treatment in the connecting pipeline equipped with a clean filtration device, the adverse effects of various metallic and non-metallic solid impurities on the electrolytic chemical reaction, instrumentation, electrical components, and container corrosion of the electrolytic cell can be reduced, the impact of impurities on the gas purification process can be reduced, the efficiency of gas separation and purification can be improved, and the cost of gas purification equipment can be reduced; because impurity deposition causes blockage of the filter element and flow channel, the airflow inside the filter decreases and the internal pressure difference of the filter increases. By performing pre-separation and filtration treatment on the gas to be treated through the lower chamber of the filter, and discharging the pre-separated and filtered gas through the upper chamber of the filter, the impurities are settled by gravity. The filter material accumulates at the bottom of the filter element, reducing the buildup of impurities on the upper part of the filter element and ensuring a large flow space in the upper chamber. This reduces the possibility of clogging, improves control efficiency and the reliability of hydrogen production control, and prevents debris from clogging the equipment and affecting its safe and normal operation. It also reduces equipment damage and effectively extends the safe service life of the equipment, as well as improving the stability, safety, and reliability of the system. At least one of the multiple connecting pipelines is equipped with a clean filtration device. By using the connecting pipelines alternately, excessive wear caused by continuous operation of a single filter can be avoided, thus extending the safe service life of the equipment. It also ensures that the hydrogen production system can operate continuously, stably, and without interruption, effectively reducing downtime caused by equipment failure and improving the stability, continuity, safety, and reliability of the system.

[0025] Brief description of the attached figures

[0026] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0027] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0028] Figure 1 is a schematic diagram of an embodiment of the hydrogen production system provided in this disclosure;

[0029] Figure 2 is a schematic diagram of the clean filtration device in Figure 1;

[0030] Figure 3 is a schematic diagram of another embodiment of the hydrogen production system provided in this disclosure;

[0031] Figure 4 is a schematic diagram of the clean filtration device shown in Figure 3.

[0032] Reference numerals: 100, Control circuit; 200, Clean filtration device; 210, Filter; 2101, Upper chamber; 2102, Lower chamber; 2111, Filter element; 2112, Filter element mounting position; 212, Separator; 213, Baffle; 214, Lower end cap; 220, Recovery tank; 300, Power supply; 400, Electrolytic cell; 500, Separation device; 600, Scrubber; 700, Cooler; 800, Circulation pump; 410, Differential pressure detection assembly; 421, First liquid level detection assembly; 422, Second liquid level detection assembly.

[0033] The purpose, features, and advantages of this disclosure will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] To better understand the technical solutions disclosed herein, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0035] To achieve the requirements of large-scale alkaline electrolyzers, high current density, and low energy consumption, as well as the development goals of large-scale, high-volume, and low-cost green hydrogen projects, the number of electrolysis chambers and the size and surface area of ​​electrodes in alkaline electrolyzers are increasing. Typically, multiple electrolyzers are operated in parallel for gas-liquid separation. However, after a period of operation, the gas purity often fails to meet requirements.

[0036] The applicant's research revealed that the gas purity did not meet requirements. Specifically, this was due to several factors during the large-scale electrolyzer processes, including electrode coating, packaging and transportation, activation treatment, and electrolyzer assembly. In alkaline electrolyzers, long-term operation, including alkaline scouring and corrosion, and reverse current generated during start-up and shutdown, caused catalyst detachment from the electrodes. Furthermore, factors such as folding and vibration weakened the honeycomb-like porous structure of the surface catalyst coating, making it highly brittle and prone to breakage and detachment. Consequently, after the electrolyzer plates were assembled, external forces easily caused large-scale detachment of the surface catalyst coating, leading to impurity deposition within the electrolyzer. This impurity deposition not only affects gas purity but also the reliability and safety of the hydrogen production system.

[0037] To overcome the impact of impurity deposition on gas purity, reliability, and safety of hydrogen production equipment, this disclosure proposes a hydrogen production device and system. This system reduces the adverse effects of various metallic and non-metallic solid impurities on the electrolytic chemical reaction of the electrolyzer, instrumentation, electrical systems, and container corrosion by pre-separating and filtering the gas to be processed, thereby optimizing gas purity and improving the continuity, reliability, and safety of the hydrogen production system.

[0038] In this disclosure, the hydrogen production apparatus includes an electrolyzer 400 and multiple connecting pipelines. The electrolyzer 400 is used to output the gas to be processed.

[0039] Each of the multiple connecting pipelines is connected to the electrolytic cell 400 to transmit the gas to be treated output from the electrolytic cell 400. At least one of the multiple connecting pipelines is equipped with a clean filtration device 200. Each clean filtration device 200 includes a filter 210, which has an upper chamber 2101 and a lower chamber 2102. The filter 210 is used to pre-separate and filter the gas to be treated that enters through the lower chamber 2102 before discharging it through the upper chamber 2101.

[0040] The system includes at least one electrolytic cell 400, which can be, for example, an alkaline electrolytic cell. The alkaline electrolytic cell uses alkaline solution as the electrolyte and produces hydrogen and oxygen after being energized. When used to treat hydrogen, the filter 210 effectively removes impurities such as water vapor, alkaline solution, oxygen, and hydrocarbons from the hydrogen. When used to treat oxygen, the filter 210 effectively removes impurities such as water vapor, alkaline solution, hydrogen, and hydrocarbons from the oxygen. In the embodiments of this disclosure, by installing a clean filtration device 200 containing the filter 210 on the connecting pipeline, the purity of the gas output from the electrolytic cell 400 can be effectively improved, and the structure is simple and the equipment cost is low.

[0041] By performing pre-separation and filtration treatments on the connecting pipelines equipped with clean filtration devices, the adverse effects of various metallic and non-metallic solid impurities on the electrolytic chemical reaction, instrumentation, electrical systems, and container corrosion of the 400 electrolytic cell can be reduced. This also reduces the impact of impurities on the gas purification process, improves the efficiency of gas separation and purification, and lowers the cost of gas purification equipment.

[0042] Due to impurity deposition, the filter element and flow channels of filter 210 become clogged, resulting in reduced airflow and increased internal pressure difference within filter 210. The lower chamber 2102 within filter 210 performs pre-separation and filtration of the gas to be treated, while the pre-separated and filtered gas is discharged through the upper chamber 2101. This utilizes gravity to deposit impurities at the bottom of filter 210, reducing impurity accumulation on the upper part of filter element 2111 and ensuring a larger flow space in the upper chamber 2101. This reduces the possibility of clogging, improves control efficiency and the reliability of hydrogen production control, and prevents debris blockage from affecting the safe and normal operation of the equipment. It also reduces equipment damage, effectively extends the safe service life of the equipment, and improves the stability, safety, and reliability of the system.

[0043] At least one of the multiple connecting pipelines is equipped with a clean filter device 200. By using the connecting pipelines in turn, excessive wear caused by continuous operation of a single filter can be avoided, thereby extending the safe service life of the equipment. It can also ensure that the hydrogen production system can operate continuously, stably, and without interruption, effectively reducing downtime caused by equipment failure and improving the stability, continuity, safety, and reliability of the system.

[0044] In practical implementation, the connecting pipeline equipped with a clean filter device 200 in the multi-connecting pipeline can be controlled to perform pre-separation and filtration of the gas to be treated before discharging the gas to the separation device or other devices; or, if there is little impurity deposition and no need to pre-treat the gas to be treated, the gas output from the electrolytic cell 400 can be directly transmitted to the separation device or other devices through the connecting pipeline without a clean filter device 200.

[0045] In one embodiment, the filter includes a filter element 2111 and a separator 212. The filter element 2111 divides the filter into an upper chamber 2101 and a lower chamber 2102; the lower chamber 2102 is provided with a first input channel N1, and the upper chamber 2101 is provided with a gas output channel N12.

[0046] The separator 212 is positioned in the lower chamber 2102 corresponding to the first input channel N1. The separator 212 is used to pre-separate the gas to be processed that enters the lower chamber 2102 through the first input channel N1. The filter element 2111 is used to filter the gas that has undergone pre-separation and discharge it through the gas output channel N12.

[0047] Optionally, the hydrogen production process can be controlled by installing check valves Z1-Z6 and regulating valves F1-F11 at the connection ports and corresponding pipelines N1-N12. The check valves are used to prevent backflow of the medium; the regulating valves are pneumatic or electric regulating valves, which control the flow rate of the medium by controlling the valve opening and closing; regulating valves F5 and F7 can optionally be special regulating valves, such as V-type regulating ball valves suitable for liquids containing a large number of solid particles, which are not limited here.

[0048] The first input channel N1 is used to input the gas to be processed (including hydrogen and oxygen to be processed, and the gas to be processed contains water vapor, other gases, alkaline solutions, carbon compounds, metal impurities, etc.), and the filter element 2111 is used to filter the gas to be processed and output the processed gas through the gas output channel N12.

[0049] The technical solution disclosed herein reduces the adverse effects of various metallic and non-metallic solid impurities on the electrolytic chemical reaction, instrumentation, and container corrosion of the electrolytic cell 400 by pre-separating the gas to be treated in advance within the filter 210, using the separation element 212 of the filter 210 for pre-separation treatment, and filtering the gas after pre-separation treatment by the filter element 2111. This reduces the impact of impurities on the gas purification process, improves the efficiency of gas separation and purification, and reduces the cost of gas purification equipment.

[0050] Optionally, the filter 210 is provided with a filter element mounting position 2112 for installing the filter element 2111. Due to impurity deposition, the filter element 2111 and flow channels of the filter 210 become clogged, resulting in reduced airflow and increased internal pressure difference. The filter element 2111, installed within the filter 210, divides the filter 210 into an upper chamber 2101 and a lower chamber 2102. The lower chamber 2102 is mainly used for pre-separation and filtration of the gas to be treated, while the upper chamber 2101 is used to discharge the gas that has undergone pre-separation and filtration. This allows impurities to be deposited at the bottom of the filter 210 by gravity, reducing the accumulation of impurities on the upper part of the filter element 2111 and ensuring a larger flow space in the upper chamber 2101 above the filter element 2111. This reduces the possibility of clogging, improves filtration efficiency, and extends the service life of the filter element 2111. Reducing clogging also reduces pressure loss of fluid passing through the filter element 2111, thus reducing system energy consumption. This design also prevents debris from clogging the equipment and affecting its safe and normal operation, reducing equipment damage and effectively extending its safe service life, while improving the system's stability, safety, and reliability. When filter element 2111 needs cleaning or replacement, the impurities are mainly concentrated at the bottom, making cleaning and replacement convenient.

[0051] Due to impurity deposition, the filter element 2111 and flow channels of filter 210 become clogged, resulting in reduced airflow within filter 210 and increased internal pressure difference. In one embodiment, the upper chamber 2101 is provided with a first interface P1, and the lower chamber 2102 is provided with a second interface P2. The clean filtration device 200 also includes a differential pressure detection component 410 and a control circuit 100. The first detection end of the differential pressure detection component 410 is connected to the first interface P1 for detecting the pressure in the upper chamber 2101; the second detection end of the differential pressure detection component 410 is connected to the second interface P1, and the differential pressure detection component 410 is used to detect the internal pressure difference between the upper chamber 2101 and the lower chamber 2102.

[0052] The control circuit 100 is connected to the differential pressure detection component 410 and is used to control the first input channel N1 and the gas output channel N12 of the filter 210 to open when the internal differential pressure is not greater than the preset first differential pressure, so that the filter switches to the working state.

[0053] Optionally, the control circuit 100 includes a voltage and current detection circuit (or power analysis circuit), a comparison circuit, a calculation circuit, etc. The control circuit 100 is connected to the electrolytic cell 400 and is used to detect the input voltage, current, and other detection signals of the working circuit of the electrolytic cell 400 through the voltage and current detection circuit, and calculate the input power of the electrolytic cell 400 based on the detection signals (or directly detect the input power of the electrolytic cell 400 through the power analysis circuit). The comparison circuit, calculation circuit, etc. in the control circuit 100 will compare the detected input power, liquid level, pressure difference, etc. with historical detection values ​​or preset detection values ​​to determine whether the input power of the electrolytic cell 400, the liquid level of the filter 210, pressure difference, etc. have changed. The control circuit 100 is also used to open or close the corresponding interface and pipeline by controlling the opening or closing of the regulating valve and other components on the corresponding interface and pipeline.

[0054] The differential pressure detection component 410 outputs a differential pressure detection signal based on the detected internal pressure difference between the upper chamber 2101 and the lower chamber 2102. When the clean filtration device 200 also includes a control circuit 100, the control circuit 100 is connected to the differential pressure detection component 410. The control circuit 100 is used to switch the filter 210 to a standby state by controlling the opening of the first input channel N1 and the gas output channel N12 according to the received differential pressure detection signal; or by controlling the closing of the first input channel N1 and the gas output channel N12 to stop the filter 210 from working.

[0055] Optionally, the differential pressure detection component 410 employs a differential pressure transmitter. When the filter element 2111 becomes clogged, the resistance to fluid flow increases, thereby increasing the pressure difference between the upper chamber 2101 and the lower chamber 2102. The differential pressure detection component 410 detects the internal pressure difference between the upper chamber 2101 and the lower chamber 2102 to detect the internal pressure difference of the filter 210, helping to determine whether clogging has occurred, and further assisting in taking corresponding filter element 2111 cleaning or replacement measures.

[0056] This configuration can improve control efficiency and the reliability of hydrogen production control, prevent debris from clogging the equipment and affecting its safe and normal operation, reduce equipment damage, effectively extend the safe service life of the equipment, and also improve the stability, continuity, safety and reliability of the system.

[0057] Referring to Figures 2 and 4, in one embodiment, a baffle 213 is provided inside the filter 210 at the position corresponding to the second interface P2, and the baffle 213 is positioned facing the second interface P2.

[0058] By setting baffle 213, it is possible to prevent foreign objects from entering the second interface P2 and causing damage to the differential pressure transmitter. It can also stabilize the flow of fluid and ensure that the differential pressure transmitter is not affected when performing pressure detection, thereby improving the stability and accuracy of differential pressure detection.

[0059] Optionally, in the vertical direction, the baffle 213 is installed below the second interface P2 and facing the second interface P2. The baffle 213 is L-shaped, arc-shaped or any other shape suitable for actual use, and is not limited here.

[0060] Metal particles can clog pipe openings and even enter detection components such as the level detection component and differential pressure detection component, causing the instrument to fail to accurately measure the liquid level and pressure inside the container, and even leading to system shutdown. By adjusting the positions of the first interface P1 and the second interface P2 of the filter 210, and by using the internal baffle 213 of the filter 210, impurities can be prevented from entering the differential pressure detection component and the level detection component. Ensuring that the interfaces are not clogged by metal particles improves detection reliability and safety, and reduces system shutdown.

[0061] Referring to Figures 1 to 4, the hydrogen production unit includes a separation device 500, and the upper chamber 2101 is equipped with a gas-liquid output channel N2 connected to the separation device 500. Based on the internal pressure difference detected by the differential pressure detection component 410, single-loop regulation is performed via the regulating valve F10. It should be noted that in actual implementation, if the filter 210 cannot flow into the hydrogen separation device by gravity, two pressure transmitters are respectively installed at the first interface P1 and the second interface P2. It is known that when the installation height of the clean filtration device 200 (including filter 210) is higher than that of the hydrogen separation device and the oxygen separation device, the resulting liquid level difference allows the alkaline solution and other media to overcome pipeline resistance and flow into the hydrogen separation device and the oxygen separation device by gravity. When the installation height of the clean filtration device (including filter 210) is not higher than that of the hydrogen separation device and the oxygen separation device, the alkaline solution and other media cannot automatically flow into the separation device 500. Therefore, it is necessary to use the pressure transmitter of the first interface P1 and the regulating valve F10 for single-loop regulation to control the internal pressure of the filter 210, so that the pressure of the filter 210 is higher than the pressure of the downstream hydrogen separation device or the oxygen separation device, creating a pressure difference that forces the alkaline solution to flow to the downstream separation device 500.

[0062] Referring to Figures 2 and 4, in one embodiment, the clean filtration device further includes a liquid level detection component, which is connected to the filter 210 and is used to detect the internal liquid level of the filter 210.

[0063] The liquid level detection component is used to detect the liquid level of filter 210. Because filter 210 experiences some pressure loss during operation, if filter 210 becomes clogged, the airflow will decrease, leading to an increase in pressure differential, and the liquid will not be able to pass through effectively, causing the liquid level to drop. Detecting whether the liquid level of filter 210 drops by the liquid level detection component can further help determine whether filter 210 is clogged.

[0064] The control circuit 100 is connected to the liquid level detection component and is used to close the first input channel N1 and the gas output channel N12 of the filter when the internal pressure difference is not less than a preset second pressure difference and the liquid level is not higher than a preset first liquid level value, so that the filter switches to standby mode. This setting can be used to realize the alternating use of the filter 210, and avoid excessive wear caused by continuous operation of a single filter 210 by using the filter 210 in turn.

[0065] The filter 210 that needs to be switched to standby mode or maintained in standby mode can be a filter 210 that becomes clogged during operation, or a filter 210 whose internal pressure difference is detected to be no less than a preset second pressure difference and whose liquid level is no higher than a preset first liquid level value before startup. By controlling the first input channel N1 and gas output channel N12 of such filter 210 to stop the clogged filter 210 from working, or to keep the clogged filter 210 from working. This is to prevent clogged filters from continuing to work, affecting gas purity and the safe and reliable operation of the system, to extend the safe service life of the equipment, and to further prevent clogs by treating such anti-clogging devices, reducing impurities, and further ensuring the safe and stable operation of the hydrogen production system.

[0066] To reduce measurement errors, improve detection accuracy, and facilitate installation and calibration, in one embodiment, the first detection end LT1 and the second detection end LT2 of the liquid level detection component are connected to the same side of the filter 210.

[0067] In one embodiment, the liquid level detection component is used to output a low liquid level alarm signal to the control circuit 100 when the liquid level of the filter 210 is not higher than a preset low liquid level value; and / or, the liquid level detection component is used to output a high liquid level alarm signal to the control circuit 100 when the liquid level of the filter 210 is not lower than a preset high liquid level value.

[0068] Optionally, the position of the gas-liquid output channel N2 can be used as the preset low liquid level value, or any position above the gas-liquid output channel N2 and below the gas output channel N12 can be used as the preset low liquid level value; the position of the gas output channel N12 can be used as the preset high liquid level value, or any position above the gas-liquid output channel N2 and below the gas output channel N12 can be used as the preset high liquid level value. The preset high liquid level value is higher than the preset low liquid level value, which is used to control the low liquid level of the filter 210 at a certain position above the gas-liquid output channel N2 of the filter 210, and to control the high liquid level of the filter 210 at a certain position below the gas output channel N12 of the filter 210, so as to avoid the liquid level being too low or too high affecting the gas purification process.

[0069] In one embodiment, the filter element 2111 is either a metal filter element or a non-metal filter element.

[0070] Among them, metal filter elements, such as metal wedge wire filter elements (composed of support rods and surface wires spirally wound on the axial support rods) or metal sintered mesh filter elements, can effectively improve filtration accuracy by utilizing the surface sieving principle of filter element 2111. Metal filter elements have low operating costs, are suitable for backwashing, and have high metal mechanical strength, which not only resists high temperatures and corrosion from alkaline solutions but also allows for online replacement. Metal filter elements are specifically suitable for alkaline water electrolysis hydrogen production units with multiple 400 electrolyzers. For example, they are suitable for scenarios where there are many alkaline electrolyzers in the hydrogen production unit, and the content of entrained solid metal impurities is relatively large with a particle size (e.g., ≥25μm). Their filtration efficiency is high, specifically reaching over 99%.

[0071] The non-metallic filter element, Filter Element 2111, is made of materials such as polypropylene, nylon, or polyphenylene sulfide. It can withstand corrosion from 30% KOH solution at temperatures above 90℃. Filter Element 2111 employs depth filtration technology and can be used in applications with relatively small particle sizes and high filtration accuracy requirements. For example, it achieves a filtration efficiency of over 99.99% for filtering solid impurities with a particle size ≥10μm, and over 90% for filtering solid impurities with a particle size ≥5μm.

[0072] Referring to Figures 2 and 4, in one embodiment, the clean filtration device 200 further includes a recovery tank 220, and a recovery channel N4 is provided at the bottom of the filter. The filter 210 is connected to the recovery tank 220 through the recovery channel N4.

[0073] The first channel N3 is used to input fluid into filter element 2111. When filter element 2111 is a metal filter element, it is used to input hydrogen, pure water, etc., into filter element 2111 when treating hydrogen; it is used to input oxygen, pure water, etc., into filter element 2111 when treating oxygen. The first channel N3 also provides backwash material to filter 210. When filter element 2111 is a non-metallic filter element, it is used to replace the non-metallic filter element when blockage occurs. Besides inputting fluid, the first channel N3 is also used to output gas. When treating hydrogen, it is used to input crude hydrogen and as a venting channel; when treating oxygen, it is used to input crude oxygen and as a venting channel. The pressure difference inside filter 210 can be adjusted by using the first channel N3.

[0074] Optionally, the recovery tank 220 is provided with a second inlet N5, an outlet N7, and a second channel N6. The second inlet N5 is connected to the recovery channel N4 of the filter 210 and is used to receive the medium to be recovered from the filter 210. The second channel N6 is used for inputting or outputting gas. The second inlet N5 of the recovery tank 220 is connected to the recovery channel N4 of the filter 210. The recovery tank 220 recovers the medium to be recovered from the filter 210, such as alkaline solution, solid impurities, and impurity gases, avoiding direct discharge that would cause environmental pollution. The recovered liquid can be reused in the hydrogen production process after appropriate treatment to improve resource utilization, reduce hydrogen production costs, and reduce pollution.

[0075] To facilitate the flow of liquid and deposited impurities, allowing them to flow more smoothly to the recovery channel N4, in one embodiment, the filter 210 includes a lower end cap 214. The lower end cap 214 is located at the bottom of the lower chamber 2102, corresponding to the position of the separator 212, and the recovery channel N4 is located within the lower end cap 214. The lower end cap 214 may optionally be configured as a cone, hemispherical, or any other shape suitable for practical use.

[0076] Taking the cone-shaped lower end cap 214 as an example, in one embodiment, the lower end cap 214 has a first connecting end and a second connecting end that are arranged opposite to each other. The first connecting end is connected to the bottom of the separator 212, and the recovery channel N4 is located at the second connecting end. The peripheral wall of the lower end cap 214 gradually decreases from the first connecting end to the second connecting end.

[0077] The second inlet N5 of the recovery tank 220 is connected to the recovery channel N4 of the filter 210 to recover the medium to be recovered conveyed by the filter 210. The lower end cap 214 at the bottom of the filter 210 can promote the flow of liquid and deposited impurities. The peripheral wall of the lower end cap 214 gradually decreases from the first connection end to the second connection end, so that the lower end cap 214 can be cone-shaped or any shape suitable for actual use, so that impurities and liquid can flow more smoothly to the recovery channel N4, which is convenient for cleaning and emptying the inside of the filter 210, preventing the accumulation of residual liquid and impurities, helping to maintain cleanliness, and preventing system corrosion.

[0078] To facilitate the smooth discharge of impurities and liquids from the outlet N7 of the recovery tank 220, prevent the accumulation of residual liquids and impurities, and further prevent system corrosion, the recovery tank 220 may optionally be provided with a lower end cap 214 at its bottom, with the outlet N7 of the recovery tank 220 located at the lower end cap 214. The lower end cap 214 of the recovery tank 220 may be configured similarly to the lower end cap 214 of the filter 210, and is not limited thereto.

[0079] Referring to Figures 2 and 4, the hydrogen production process is controlled by installing check valves Z1-Z6 and regulating valves F1-F11 at the connection ports and corresponding pipelines N1-N12. The check valves prevent backflow of the medium; the regulating valves are pneumatic or electric, controlling the flow rate of the medium by adjusting the valve opening and closing; regulating valves F5 and F7 can optionally be special regulating valves, such as V-type ball valves suitable for liquids containing a large number of solid particles, and are not limited here.

[0080] For example, a level detection assembly has a level transmitter port. This level detection assembly serves as the first level detection assembly 421. One end of the first level detection assembly 421 (first detection end LT1) is connected to the upper chamber 2101, and the other end (second detection end LT2) is connected to the lower chamber 2102. The control circuit 100 is connected to this level detection assembly. A differential pressure detection assembly 410 has a differential pressure transmitter port. One end of the differential pressure detection assembly 410 is connected to a first interface P1 located in the upper chamber 2101, and the other end is connected to a second interface P2 located in the lower chamber 2102. The control circuit 100 is connected to the differential pressure detection assembly 410.

[0081] The hydrogen production unit includes a separation device 500. The upper chamber 2101 has a gas-liquid output channel N2 communicating with the separation device 500. The gas output channel N12 of the filter 210 is connected to the interface N11 of the separation device 500 of the hydrogen production unit via a pipeline. The pipeline is equipped with a check valve Z5 (or check valve Z6) and a regulating valve F10, wherein the control circuit 100 is connected to the regulating valve F10. The gas-liquid output channel N2 of the filter 210 is connected to the interface N8 of the separation device 500 via a pipeline. The pipeline is equipped with a check valve Z1 and a regulating valve F1, wherein the control circuit 100 is connected to the regulating valve F1. The first input channel N1 is connected to the electrolyzer 400 of the hydrogen production unit for receiving the gas to be treated (hydrogen or oxygen to be treated) containing an alkaline mixture from the electrolyzer 400. The pipeline is equipped with a regulating valve F2 and a check valve Z2, wherein the control circuit 100 is connected to the regulating valve F2. Gas output channel N12 is mainly used as the crude hydrogen (or crude oxygen) outlet of the alkali filter, and gas-liquid output channel N2 is mainly used as the alkali liquid (containing a small amount of gas) outlet of the alkali filter.

[0082] The recovery channel N4 of filter 210 is connected to the second inlet N5 of recovery tank 220 for conveying the medium to be recovered to recovery tank 220. A special regulating valve F5 and a check valve Z3 are installed on the connecting pipeline between the two. Control circuit 100 is connected to the special regulating valve F5. Recovery tank 220 has a second channel N6, which is equipped with regulating valve F6 and check valve Z4. Control circuit 100 is connected to regulating valve F6.

[0083] The recovery tank 220 is equipped with another liquid level detection component, which serves as the second liquid level detection component 422. The third detection terminal LT3 and the fourth detection terminal LT4 of the second liquid level detection component 422 are respectively connected to the interface on the recovery tank 220, and the control circuit 100 is connected to this liquid level detection component. Specifically, the third detection terminal LT3 is connected above the fourth detection terminal LT4, and the fourth detection terminal LT4 is connected to the interface located near the discharge port N7 to ensure that the interface is not blocked by metal debris particles, thereby improving detection reliability and safety and reducing system shutdowns. The second liquid level detection component 422 is used to detect the liquid level inside the recovery tank 220, and its specific implementation is the same as that of the first liquid level detection component 421, and will not be described again here.

[0084] A special regulating valve F7 is installed on the discharge port N7 of the recovery tank 220, and the control circuit 100 is connected to the special regulating valve F7. The separation device 500 is connected to the scrubber 600 through the output port N9 and to the cooler 700 through the connection port N10, so as to cool the alkaline solution conveyed by the separation device 500 through the cooler 700.

[0085] When filter element 2111 is a metal filter element, the first channel N3 is used to input hydrogen (or oxygen), pure water, etc., into filter element 2111. When filter element 2111 is a non-metallic filter element, the first channel N3 is used not only for inputting fluid but also for outputting gas and serving as a venting channel. Therefore, when the filter element type is different, except for the valve assembly on the first channel N3, the valve assemblies on other interfaces and connecting pipes are basically the same. For example, referring to Figure 2, when filter element 2111 uses a metal filter element, the first channel N3 is equipped with regulating valve F3 and regulating valve F4, and the control circuit 100 is connected to regulating valve F3 and regulating valve F4. Referring to Figure 4, when filter element 2111 uses a non-metallic filter element, the first channel N3 is equipped with regulating valve F3 and check valve Z4, and the control circuit 100 is connected to regulating valve F3 and check valve Z4.

[0086] When used in hydrogen production units with a large number of alkaline electrolyzers or where filtration accuracy requirements are not high, metal filter elements are used; when used in applications requiring high filtration accuracy, non-metal filter elements are used.

[0087] It should be noted that when the hydrogen production unit includes multiple clean filtration devices 200, the filter element type of the filter 210 of each clean filtration device 200 can be the same or different. For example, depending on the application scenario and usage requirements, all filters 210 of the hydrogen production unit can be set to use metal filter elements; or, all filters 210 of the hydrogen production unit can be set to use non-metal filter elements; or, when the number of electrolyzers 400 is small, the accuracy requirements are uncertain or not high, some filters 210 of the hydrogen production unit can be set to use metal filter elements, while other filters 210 can be set to use non-metal filter elements.

[0088] The control circuit 100 is connected to the differential pressure detection component 410 and is used to control the first input channel N1 and the gas output channel N12 of the filter 210 to open when the internal differential pressure is not greater than the preset first differential pressure, so that the filter 210 switches to the working state; the control circuit 100 is also connected to the aforementioned first liquid level detection component 421 and is used to control the first input channel N1 and the gas output channel N12 of the filter 210 to close when the internal differential pressure is not less than the preset second differential pressure and the liquid level is not higher than the preset first liquid level value, so that the filter 210 switches to the standby state.

[0089] In one embodiment, when the filter element 2111 is a metal filter element: the control circuit 100 controls the opening of the recovery channel N4 of the filter 210 in standby mode. When the filter 210 is in standby mode, the control circuit 100 controls the opening of the recovery channel N4 of the filter 210 in standby mode, controls the opening of the first channel N3 at preset time intervals, and controls the input of fluid at a first target pressure to the filter element 2111 after each opening of the first channel N3. Until the recovery channel N4 of the filter 210 in standby mode is closed, and fluid at a second target pressure is input to the filter element 2111 through the first channel N3, the internal pressure difference of the filter 210 in standby mode is not greater than the preset first pressure difference. When the recovery channel N4 of the filter 210 in standby mode is closed, and fluid at a second target pressure is input to the filter element 2111 through the first channel N3, if the internal pressure difference of the filter 210 in standby mode is not greater than the preset first pressure difference, then it is determined that the backwashing process of the filter 210 in standby mode is completed.

[0090] It should be noted that when the recovery channel N4 of the filter 210 in standby state is closed and fluid with the second target pressure is input to the filter element 2111 through the first channel N3, if the internal pressure difference of the filter 210 in standby state is still greater than the preset first pressure difference, the steps of controlling the first channel N3 of the filter 210 in standby state to open at preset time intervals and controlling the input of fluid with the first target pressure to the filter element 2111 after each opening of the first channel N3 are repeated.

[0091] Specifically, the first channel N3 of the filter 210 in standby mode can be opened according to a preset time interval, and after each opening of the first channel N3, fluid with a first target pressure can be input to the filter element 2111. After repeating this a set number of times, the recovery channel N4 of the filter 210 in standby mode can be closed. When fluid with a second target pressure is input to the filter element 2111, the internal pressure difference of the filter 210 is obtained to determine whether the backwashing process of the filter 210 in standby mode is completed; or, the process of controlling the filter 210 in standby mode according to the preset time interval can be repeated. The process involves opening channel N3 and controlling the input of fluid at a first target pressure to filter element 2111 after each opening of channel N3, until a significant change occurs in the internal pressure difference or liquid level of filter 210. At this point, the cycle stops, and the recovery channel N4 of filter 210 in standby mode is closed. When fluid at a second target pressure is input to filter element 2111, the backwashing process of filter 210 in standby mode is determined based on the obtained internal pressure difference. The specific settings can be adjusted according to actual conditions and are not limited here.

[0092] In embodiments of this disclosure, the first target pressure is greater than the second target pressure, and the second target pressure is within the operating pressure range of the hydrogen production device. Optionally, the first target pressure is determined based on a general pressure that can disperse impurities, and the first target pressure is not greater than the maximum pressure that the filter 210 can withstand; the second target pressure is set according to the operating pressure range of the hydrogen production device.

[0093] When filter element 2111 is a metal filter element, the fluid used for backwashing is pure water, hydrogen, or oxygen. All backwashing fluids originate from within the hydrogen production unit, eliminating the need for additional equipment. The pure water comes from the demineralized water supplied to the electrolyzer 400 within the hydrogen production unit. When treating hydrogen, the input hydrogen can be purified hydrogen or crude hydrogen obtained after gas-liquid separation. Similarly, when treating oxygen, the input oxygen can be purified oxygen or crude oxygen obtained after gas-liquid separation.

[0094] Taking the use of pure water for backwashing as an example, the pure water comes from the pure water preparation system that supplies water to the electrolyzer 400. When the first target pressure is 3 MPa, the second target pressure is 1.8 MPa, and the general water supply pressure is 0.4 MPa, the pure water enters the filter 210 from the first channel N3. The control circuit 100 controls the opening of the regulating valve F3 and the special regulating valve F5. The control circuit 100 controls the pressure boosting valve F4 to increase the pure water pressure from 0.4 MPa to above 3 MPa, and opens the regulating valve F3 at preset time intervals to perform oscillating backwashing on the filter element 2111, so as to impact and detach the filter cake outside the filter element 2111.

[0095] The recovery tank 220 is equipped with a second liquid level detection component 422. The third detection end LT3 and the fourth detection end LT4 of the second liquid level detection component 422 are respectively connected to the interface on the recovery tank 220. During backwashing, the values ​​of the third detection end LT3 and the fourth detection end LT4 must be monitored to prevent the tank from becoming completely filled with liquid. After a certain number of backwashing cycles, pure water is used for circulation. For example, after a set number of backwashing cycles, the recovery channel N4 of the filter 210 in standby mode is closed. When pure water at 1.8 MPa is input to its filter element 2111, if the differential pressure detection component 410 detects that the internal pressure difference of the filter 210 is not greater than the first preset pressure, that is, the pressure difference value before and after the first interface P1 and the second interface P2 returns to normal, then the backwashing process of the filter 210 in standby mode is determined to be complete.

[0096] During the backwashing of the standby filter 210, the recovery channel N4 of the filter 210 remains connected to the second inlet N5 of the recovery tank 220. After the backwashing of the standby filter 210 is completed, the recovery tank 220 connected to the standby filter 210 will be filled with alkaline solution, solid metal impurities, and hydrogen (or oxygen). The control circuit 100 controls the regulating valve F6 to open, so that the residual hydrogen (or oxygen) in the recovery tank 220 is vented through the second channel N6 of the recovery tank 220 to the vent pipe in the hydrogen production unit. After venting is completed, the control circuit 100 controls the special regulating valve F7 to open, so that the alkaline solution and solid metal impurities are discharged through the outlet N7 of the recovery tank 220. The third detection terminal LT3 / fourth detection terminal LT4 of the second liquid level detection component 422 detects whether the tank is empty. For example, if the detected liquid level in the tank is not higher than the preset venting liquid level, it is determined that the tank is empty, and the control circuit 100 controls the regulating valve F6 and the special regulating valve F7 to close.

[0097] In another embodiment, when the filter element 2111 is a non-metallic filter element, when it is determined that the filter element 2111 is clogged, the filter element 2111 in the standby filter 210 needs to be replaced.

[0098] The control circuit 100 is used to control the opening of the first channel N3 of the filter 210 in standby mode to discharge gas from the filter 210 in standby mode. The control circuit 100 is also used to control the opening of the recovery channel N4 of the filter 210 in standby mode, and when the liquid level in the filter 210 reaches a preset emptying level, based on the received feedback signal after the replacement of the filter element 2111, control the input of fluid through the first channel N3 to the filter 210 in standby mode. This is used to input fluid through the first channel N3 to the filter 210 in standby mode after confirming that the filter element 2111 has been replaced, thus completing the anti-clogging treatment for the filter 210 in standby mode.

[0099] The control circuit 100 controls the opening of the regulating valve F3 to vent the residual hydrogen (or oxygen) in the filter 210 to the hydrogen vent pipe (or oxygen vent pipe) of the hydrogen production unit. Then, the regulating valve F5 is opened to discharge the residual alkaline solution and solid metal impurities to the recovery tank 220. The third detection terminal LT3 / fourth detection terminal LT4 of the second liquid level detection component 422 is used to detect whether the tank is empty. For example, if the detected liquid level in the pipe is not higher than the preset emptying liquid level, it is determined that the tank is empty. After confirming that the tank is empty, the container flange fasteners of the filter 210 are removed, the container is opened, and the non-metallic filter element inside the container is replaced. After the filter element 2111 is replaced, a feedback signal can be sent by locking the flange or pressing the button. The control circuit 100 then uses the feedback signal to draw pure water from the hydrogen production unit and inputs pure water into the filter 210 in standby mode through the first channel N3 to clean the inside of the filter 210 in standby mode.

[0100] When performing anti-clogging treatment on the standby filter 210, the recovery channel N4 of the filter 210 remains connected to the second inlet N5 of the recovery tank 220. After the filter element 2111 is replaced and the inside of the standby filter 210 is cleaned, the recovery tank 220 connected to the standby filter 210 will be filled with alkaline solution, solid metal impurities, and hydrogen (or oxygen). The control circuit 100 controls the regulating valve F6 to open, so that the residual hydrogen (or oxygen) in the recovery tank 220 is vented through the second channel N6 of the recovery tank 220 to the vent pipe in the hydrogen production unit. After venting is completed, the control circuit 100 controls the special regulating valve F7 to open, so that the alkaline solution and solid metal impurities are discharged through the outlet N7 of the recovery tank 220. The third detection terminal LT3 / fourth detection terminal LT4 of the second liquid level detection component 422 detects whether the tank is empty. For example, if the detected liquid level in the tank is not greater than the preset emptying liquid level, it is determined that the tank is empty, and the control circuit 100 controls the regulating valve F6 and the special regulating valve F7 to close.

[0101] In one embodiment, the hydrogen production apparatus includes a separation device 500, a scrubber 600, and a cooler 700. The upper chamber 2101 is provided with a gas-liquid output channel N2 communicating with the separation device 500. The separation device 500 has a first output channel and a second output channel. The separation device 500 is connected to the scrubber 600 through the first output channel and to the cooler 700 through the second output channel. The cooler 700 is used to cool the electrolyte delivered by the separation device 500.

[0102] Optionally, the hydrogen production device may also include, but is not limited to, a control circuit 100, a power supply 300, and a circulation pump 800. Specifically, a clean filter 200, a separation device 500, a scrubber 600, a cooler 700, and a circulation pump 800 may be provided for the hydrogen side and the oxygen side respectively, and used to process the hydrogen and oxygen to be processed respectively.

[0103] For example, the control circuit 100 is connected to the power supply 300, the electrolytic cell 400, and the clean filtration device 200, respectively. The control circuit 100 outputs analog signals to the power supply 300, which supplies power to the electrolytic cell 400. The gas to be treated (hydrogen and oxygen) generated by the electrolytic cell 400 is sent to the clean filtration device 200. The filter element 2111 of the filter 210 filters out the tiny particles in the gas to be treated. After preliminary purification, the treated gas is sent to the separation device 500. The alkaline solution in the separation device 500 is cooled by the cooler 700. The separation device 500 separates the gas to remove the alkaline solution. The gas is then sent to the scrubber 600, where residual alkaline solution and water vapor are removed to obtain a purer gas (hydrogen or oxygen). The scrubber 600 then sends the gas to the next process equipment to complete the subsequent processing and storage of the gas.

[0104] The system includes at least one electrolytic cell 400, which can be, for example, an alkaline electrolytic cell. An alkaline electrolytic cell uses alkaline solution as the electrolyte and produces hydrogen and oxygen when energized. A power supply 300 provides current and voltage to the electrolytic cell 400. A scrubber 600, acting as a pressure vessel, uses pure water to wash and cool the hydrogen (or oxygen). Water consumed by the electrolytic cell 400 can be replenished through the scrubber 600. A clean filtration device 200 includes a filter 210 and a recovery tank 220. The filter 210, acting as a filtration device, is a pressure vessel equipped with a specially designed filter element 2111 and is used to hold materials. The recovery tank 220 is used to recover the media and other materials conveyed by the filter 210 and to discharge waste alkaline solution, solid particles, hydrogen, oxygen, etc. A separation device 500 can, for example, be a pressure vessel that separates hydrogen (or oxygen) from the alkaline solution by gravity. A cooler 700 can, for example, be a heat exchanger that uses low-temperature cooling water to cool the alkaline solution. The circulating pump 800, as the power equipment, can be a canned pump, used to pump the circulating alkaline solution back to each electrolytic cell 400.

[0105] The control circuit 100 includes a voltage and current detection circuit (or power analysis circuit), a comparison circuit, a calculation circuit, etc. The control circuit 100 is connected to the electrolytic cell 400 and is used to detect the input voltage, current, and other detection signals of the working circuit of the electrolytic cell 400 through the voltage and current detection circuit, and calculate the input power of the electrolytic cell 400 based on the detection signals (or directly detect the input power of the electrolytic cell 400 through the power analysis circuit). The comparison circuit and calculation circuit in the control circuit 100 compare the detected input power, liquid level, pressure difference, etc. with historical detection values ​​or preset detection values ​​to determine whether the input power of the electrolytic cell 400, the liquid level of the filter 210, the internal pressure difference, etc. have changed. The control circuit 100 is also used to open or close the corresponding interfaces and pipeline channels by controlling the opening or closing of the regulating valves and other components on the corresponding interfaces and pipelines.

[0106] This disclosure also proposes a hydrogen production system, which includes a control circuit and a hydrogen production device. The beneficial effects of the hydrogen production system provided by this disclosure are the same as those of the hydrogen production device provided in the above embodiments, and its specific implementation is the same as that disclosed in the above embodiments, and will not be repeated here.

[0107] In related technologies, the gas purity of an alkaline electrolytic cell 400 fails to meet standards after a period of normal operation. The causes include: ① Deposition of metallic impurities in the alkaline solution flow channel or the hydrogen / oxygen general flow channel of the electrolytic cell 400 causes a short circuit between the two electrode plates, resulting in additional electrochemical reactions and gas production. The deposition of metallic impurities leads to "parasitic electrolysis" within the electrolysis chamber, producing hydrogen and oxygen. ② Damage to the diaphragm cloth caused by metallic impurities carried by the alkaline solution over long-term operation; metallic impurities within the electrolytic cell 400 can penetrate the diaphragm cloth, causing a short circuit and generating localized high temperatures that burn the diaphragm cloth, allowing gases to permeate. ③ Blockage of the inlet or outlet flow channels of the electrolysis chamber, or blockage of the gas outlet convergence channel or the alkaline solution circulation system, creates a high-pressure difference between the two electrolysis chambers on either side of the diaphragm cloth, leading to gas permeation. ④ Severe electrochemical corrosion may occur within the electrolysis chamber, causing perforation of the electrode plates. The hydrogen production apparatus and system disclosed herein can remove metallic impurities from the electrolysis chamber, preventing "parasitic electrolysis" from producing hydrogen and oxygen, effectively improving the purity of oxygen in hydrogen and hydrogen in oxygen, and solving the problem of substandard purity of oxygen in hydrogen and hydrogen in oxygen. It also avoids the erosion and wear of the diaphragm cloth by solid metallic impurities and prevents burn-out caused by short circuits. Through anti-clogging treatment and reduction of impurities, hydrogen and oxygen do not interpenetrate, thus extending the service life of the diaphragm cloth, improving the purity of oxygen in hydrogen and hydrogen in oxygen, preventing explosions inside the electrolytic cell 400, preventing the gas and liquid channels of the alkaline electrolytic cell 400 from being eroded, corroded, and blocked by solid metallic impurities, and preventing electrochemical corrosion and electrode plate damage caused by impurities in the electrolysis chamber of the alkaline electrolytic cell 400, effectively improving the reliability and safety of system operation.

[0108] Hydrogen and alkaline solution (containing metallic impurities) and oxygen and alkaline solution (containing metallic impurities) generated by the alkaline electrolyzer 400 enter the hydrogen separator and oxygen separator respectively for gas-liquid separation. The alkaline solution carrying metallic impurities, upon entering the hydrogen and oxygen separators, causes abrasive corrosion, damaging the electroless nickel plating layer on the container surface, greatly accelerating the corrosion rate, leading to localized corrosion, leakage, and failure, resulting in a safety accident. The hydrogen production device and system provided in this disclosure, through anti-clogging treatment and impurity reduction, can also prevent solid metallic impurities in the alkaline solution from eroding and corroding the inner walls of the hydrogen and oxygen separator containers, thereby ensuring the service life of the electrolyzer 400 and ensuring the safe and stable operation of the hydrogen production system.

[0109] Excessive amounts of impurities can cause corrosion and wear at the tube-to-tube welds of the heat exchanger tubes and tube sheet when the alkaline solution containing metallic particles enters the alkaline cooler 700. This damages the passivation film on the welds, leading to leakage and causing the tube-side alkaline solution to leak into the shell-side circulating cooling water, triggering a system shutdown. Furthermore, alkaline solution containing metallic particles entering the alkaline circulating pump can impact and wear the impeller blades, causing damage and significantly reducing the pump's lifespan, resulting in economic losses. This disclosure protects the tube-to-tube welds of the alkaline cooler 700 from erosion and corrosion, preventing tube-to-shell leakage and subsequent shutdowns, and protects the impeller and blades of the alkaline circulating pump from damage by solid metallic impurities in the alkaline solution, extending the pump's lifespan and reducing economic losses.

[0110] Referring to Figures 1 to 4, the specific implementation process of the hydrogen production system of this disclosure is as follows: Determine the relevant parameters of the clean filtration device 200: After determining the operating parameters of the electrolyzer 400, determine the number of clean filtration devices 200 and the parameters of the filter 210 based on the operating parameters of the electrolyzer 400; wherein, the operating parameters of the electrolyzer 400 include at least one of the following: the number of electrolyzers 400, impurity particle size, and impurity filtration efficiency; the parameters of the filter 210 include at least one of the following: filter element type, number of filter elements 2111, filter 210 size, liquid collection volume of the filter 210, and parameters of the lower end cap 214 of the filter 210. For example, the type of filter element selected is determined based on the operating parameters of the electrolyzer 400. Taking a metal filter element as an example, the absolute filtration accuracy of the wedge wire filter element (such as 25 μm or any value suitable for actual use) is determined based on the size of the solid metal impurities collected at the outlet during the alkaline electrolyzer test, in order to block most impurities (such as 95% of harmful metal impurity particles). Taking non-metallic filter elements as an example, the absolute filtration accuracy of the non-metallic filter element (such as 10μm or any value suitable for actual use) is determined based on the size of the solid metal impurities collected at the outlet during the alkaline electrolysis cell test, in order to block the vast majority of harmful metal impurity particles.

[0111] Based on the alkaline solution flow rate and viscosity, solid metal particle size, the content of solid metal impurities in the liquid alkali, and the operating temperature, determine the number, model, and size of the selected filter elements 2111. Arrange the filter elements 2111 according to their quantity, and further determine the diameter and other dimensions of the filter 210.

[0112] To facilitate the disassembly of filter element 2111, a container flange or manhole is provided in filter 210.

[0113] The lower end cap 214 of the filter 210 adopts a conical end cap, and the angle of the conical section of the lower end cap 214 is set to be greater than the angle of repose of solid metal particles determined by experiments and tests. Each filter element 2111 is equipped with a dedicated backwashing conduit to facilitate backwashing. The interior of the filter 210 container is polished, and the roughness is limited to less than Ra0.8μm to reduce the coefficient of friction and facilitate the flow of the medium within the container.

[0114] The dimensions of the recovery tank 220 are determined based on the liquid collection volume of the filter 210. For example, the dimensions of the recovery tank 220 can be determined to be 1.2 to 1.5 times the volume of the portion from the filter element installation position 2112 to the lower end cap 214, to ensure that the recovery tank 220 can recover the liquid discharged from the filter 210 during the draining process. The lower end cap 214 of the recovery tank 220 can also be a conical end cap. The angle of the conical section of the lower end cap 214 of the recovery tank 220 must be greater than the angle of repose of the solid metal particles as determined by experiments and tests. The interior of the recovery tank 220 is polished, and the roughness is limited to less than Ra0.8μm to reduce the coefficient of friction and facilitate the discharge of liquid and impurities.

[0115] When there are few impurities deposited and no pretreatment is required for the gas to be treated: the gas to be treated output from the electrolytic cell 400 is directly transmitted to the separation device or other device through the connecting pipeline without a clean filter device 200.

[0116] When pretreatment of the gas to be treated is required, the clean filter device 200 is controlled to work: because the impurities in the filter 210 include not only the impurities brought by the gas to be treated during the operation of the hydrogen production unit, but also the impurities of the filter 210 itself, it is necessary to control the working device to work before starting the machine. That is, it is necessary to control the first input port of the working device to connect with the electrolysis cell 400 and control the output port of the working device to open, so as to avoid the impurities of the filter 210 itself from causing clean blockage and affecting the purity of the gas. Taking the treatment of hydrogen as an example, the hydrogen production unit includes a first clean filtration device and a second clean filtration device. The first clean filtration device includes a first filter, and the second clean filtration device includes a second filter. The following explanation uses the first filter as the working device and the second filter as the backup device: Before starting the hydrogen production unit, the working device is switched into the alkaline solution circulation pipeline. For example, the regulating valves F1, F2, and F10 of the first filter are opened, and the valves F3, F5, F6, F7, F8, F9, and F11 of the first filter are closed. Hydrogen and alkaline solution containing metal solids enter the first filter through the first input channel N1. The first input channel N1 is equipped with an inlet separator 212 to settle larger metal solid particles to the bottom. The remaining hydrogen and alkaline solution containing metal solids flow from the outside of the filter element 2111 to the inside for filtration and separation. After filtration and separation, the clean alkaline solution (carrying a small amount of hydrogen) flows out from the gas-liquid outlet N2 of the first filter, and most of the crude hydrogen (carrying alkaline droplets) flows out from the gas outlet N12 of the first filter.

[0117] Taking the differential pressure detection component 410, such as the differential pressure transmitter, as an example where the initial differential pressure is set to 10 kPa, when the differential pressure inside the first filter is detected to be higher than the preset second differential pressure (such as the set value of 0.1 MPa), and the first level transmitter detects that the liquid level in the first filter is gradually decreasing, it is determined that a large filter cake has formed on the filter element 2111 inside the first filter and the effective filtration area is blocked, thus confirming that the first filter is blocked.

[0118] When the first filter becomes clogged, the regulating valves F1, F2, and F10 of the second filter are opened. When the liquid level of the second filter is stable within the preset liquid level range (the liquid level is not greater than the preset high liquid level value and not less than the preset low liquid level value), the regulating valves F1, F2, and F10 of the first filter are gradually closed, and the second filter is used as the working device. The alkali solution is then connected to the circulation pipeline through the second filter for filtration and separation.

[0119] The first filter is switched to standby mode by means of stopping operation, and anti-clogging treatment is performed on the first filter: When the filter element type of filter element 2111 is a metal filter element, taking the backwashing with pure water as an example, the pure water comes from the pure water preparation system that supplies water to the electrolyzer 400. When the first target pressure is 3Mpa, the second target pressure is 1.8Mpa, and the general water supply pressure is 0.4Mpa, the pure water enters the filter 210 from the first channel N3. The control circuit 100 controls the opening of the regulating valve F3 and the special regulating valve F5 of the first filter. The control circuit 100 controls the pressure boosting valve F4 of the first filter to increase the pure water pressure from 0.4Mpa to above 3Mpa, and opens the regulating valve F3 at preset time intervals to perform oscillating backwashing on the filter element 2111, so as to impact and detach the filter cake outside the filter element 2111.

[0120] After the set number of backwash cycles, the recovery channel N4 of the first filter is closed. When pure water at 1.8 MPa is input to its filter element 2111, if the differential pressure detection component 410 detects that the internal differential pressure of the first filter is not greater than the first preset pressure, that is, when the differential pressure values ​​before and after the first interface P1 and the second interface P2 return to normal, the backwashing process of the first filter is determined to be completed.

[0121] During the backwashing of the first filter, the recovery channel N4 of the first filter remains connected to the second inlet N5 of the recovery tank 220. After the backwashing of the first filter is completed, the recovery tank 220 connected to the first filter will be filled with alkaline solution, solid metal impurities, and hydrogen. The control circuit 100 controls the regulating valve F6 to open, so that the residual hydrogen in the recovery tank 220 is vented through the second channel N6 of the recovery tank 220 to the vent pipe in the hydrogen production unit. After venting, the control circuit 100 controls the special regulating valve F7 to open, so that the alkaline solution and solid metal impurities are discharged through the outlet N7 of the recovery tank 220. The third detection terminal LT3 / fourth detection terminal LT4 of the second liquid level detection component 422 detects whether the tank is empty. For example, if the detected liquid level in the tank is not greater than the preset emptying liquid level, it is determined that the tank is empty, and the control circuit 100 controls the regulating valve F6 and the special regulating valve F7 to close.

[0122] When the filter element 2111 is a non-metallic filter element, the control circuit 100 controls the regulating valve F3 to open, releasing the residual hydrogen in the first filter to the hydrogen vent pipe of the hydrogen production unit. Then, the regulating valve F5 of the first filter is opened to discharge the residual alkaline solution and solid metal impurities to the recovery tank 220. The third detection terminal LT3 / fourth detection terminal LT4 of the second liquid level detection component 422 is used to detect whether the tank is empty. For example, if the detected liquid level in the pipe is not greater than the preset emptying liquid level, it is determined that the tank is empty. After confirming that the tank is empty, the container flange fasteners of the first filter are removed, the container is opened, and the non-metallic filter element inside the container is replaced. After the filter element 2111 is replaced, a feedback signal can be generated by locking the flange or pressing the button. The control circuit 100 then uses pure water from the hydrogen production unit based on the feedback signal and inputs pure water into the first filter through the first channel N3 to clean the inside of the first filter.

[0123] During the anti-clogging treatment of the first filter element, the recovery channel N4 of filter 210 remains connected to the second inlet N5 of the recovery tank 220. After the filter element 2111 is replaced and the inside of the filter 210 in standby state is cleaned, the recovery tank 220 connected to the first filter will be filled with alkaline solution, solid metal impurities, and hydrogen. The control circuit 100 controls the regulating valve F6 to open, so that the residual hydrogen in the recovery tank 220 is vented through the second channel N6 of the recovery tank 220 to the vent pipe in the hydrogen production unit. After venting, the control circuit 100 controls the special regulating valve F7 to open, so that the alkaline solution and solid metal impurities are discharged through the outlet N7 of the recovery tank 220. The third detection terminal LT3 / fourth detection terminal LT4 of the second liquid level detection component 422 detects whether the tank is empty. For example, if the detected liquid level in the tank is not greater than the preset emptying liquid level, it is determined that the tank is empty, and the control circuit 100 controls the regulating valve F6 and the special regulating valve F7 to close.

[0124] For specific implementation methods for treating oxygen, please refer to the aforementioned embodiments for treating hydrogen, which will not be repeated here.

[0125] The above description is only a part of the embodiments of this disclosure and does not limit the patent scope of this disclosure. All equivalent structural transformations made under the technical concept of this disclosure using the contents of this specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this disclosure.

Claims

1. A hydrogen production apparatus, wherein, include: An electrolytic cell is used to output the gas to be processed. Multiple connecting pipelines, each of which is connected to the electrolytic cell, for conveying the gas to be processed output from the electrolytic cell; At least one of the multiple connecting pipelines is equipped with a clean filtration device. Each clean filtration device includes a filter, which has an upper chamber and a lower chamber. The filter is used to pre-separate and filter the gas to be treated that enters through the lower chamber, and then discharge it through the upper chamber.

2. The hydrogen production apparatus as described in claim 1, wherein, The filter contains a filter element and a separator. The filter element divides the filter into an upper chamber and a lower chamber. The lower chamber has a first input channel, and the upper chamber has a gas output channel. The separator is located in the lower chamber corresponding to the position of the first input channel, and the separator is used to pre-separate the gas to be processed that enters the lower chamber through the first input channel. The filter element is used to filter the gas that has undergone pre-separation treatment and discharge it through the gas output channel.

3. The hydrogen production apparatus as described in claim 2, wherein, The upper chamber is provided with a first interface, and the lower chamber is provided with a second interface; The clean filtration device further includes a differential pressure detection component and a control circuit. The first detection end of the differential pressure detection component is connected to the first interface, and the second detection end of the differential pressure detection component is connected to the second interface. The differential pressure detection component is used to detect the internal pressure difference between the upper chamber and the lower chamber. The control circuit is connected to the differential pressure detection component and is used to control the first input channel and the gas output channel of the filter to open when the internal differential pressure is not greater than a preset first differential pressure, so that the filter switches to the working state.

4. The hydrogen production apparatus as described in claim 3, wherein, The filter has a baffle at the position corresponding to the second interface, and the baffle is oriented toward the second interface.

5. The hydrogen production apparatus as described in claim 3, wherein, The clean filtration device also includes a liquid level detection component, which is connected to the filter and used to detect the internal liquid level of the filter; The control circuit is connected to the liquid level detection component and is used to control the first input channel and the gas output channel of the filter to close when the internal pressure difference is not less than a preset second pressure difference and the liquid level is not higher than a preset first liquid level value, so that the filter switches to standby state.

6. The hydrogen production apparatus as described in claim 5, wherein, The liquid level detection component is used to output a low liquid level alarm signal to the control circuit when the liquid level in the filter is not higher than a preset low liquid level value; And / or, the liquid level detection component is used to output a high liquid level alarm signal to the control circuit when the liquid level in the filter is not lower than a preset high liquid level value.

7. The hydrogen production apparatus according to any one of claims 2-6, wherein, The filter element can be either a metal filter element or a non-metal filter element.

8. The hydrogen production apparatus according to any one of claims 1-7, wherein, The clean filtration device also includes a recycling tank, and the bottom of the filter is provided with a recycling channel, through which the filter is connected to the recycling tank.

9. The hydrogen production apparatus as described in claim 8, wherein, The upper chamber of the filter is provided with a first channel, and the filter element is provided inside the filter; The clean filtration device also includes a control circuit. When the filter element is a metal filter element and the filter is in standby mode, the control circuit controls the recovery channel to open, controls the first channel to open at preset time intervals, and controls the input of fluid with a first target pressure to the filter element after each opening of the first channel.

10. The hydrogen production apparatus as described in claim 8, wherein, The upper chamber of the filter is provided with a first channel, and the filter element is provided inside the filter; The clean filtration device also includes a control circuit. When the filter element is a non-metallic filter element and the filter is in standby mode, the control circuit controls the opening of the recovery channel and the first channel.

11. The hydrogen production apparatus as claimed in claim 8, wherein, The filter includes a lower end cap located at the bottom of the lower chamber, and the recovery channel is located on the lower end cap.

12. The hydrogen production apparatus according to any one of claims 2-6, wherein, The hydrogen production device includes a separation device, a scrubber, and a cooler, and the upper chamber is provided with a gas-liquid output channel connected to the separation device; The separation device is provided with a first output channel and a second output channel. The separation device is connected to the scrubber through the first output channel and to the cooler through the second output channel. The cooler is used to cool the electrolyte delivered by the separation device.

13. A hydrogen production system, wherein, It includes a control circuit and a hydrogen production apparatus as described in any one of claims 1-12.

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