A method and system for controlling the electrolytic hydrogen production process based on infrasound-assisted anti-fouling

Abstract

This application relates to the field of hydrogen electrolysis technology, and discloses a method and system for controlling the hydrogen electrolysis process based on infrasound synergistic anti-scaling. The method includes using a cathode with a negatively charged surface layer to perform a hydrogen electrolysis reaction of seawater or reclaimed water in an electrolysis zone. During the reaction, infrasound of a preset frequency is applied to the electrolysis zone and its circulation pipeline system to regulate the thermal energy of the seawater or reclaimed water entering the zone to achieve a preset electrolysis temperature range. An alternating current signal is periodically applied to the cathode, and the functional state of the negatively charged surface layer is determined based on the electrochemical impedance characteristics of the cathode surface to determine whether it meets preset repair conditions. When the functional state meets the preset repair conditions, an electrochemical pulse is applied to the cathode to guide the iodine-containing components in the seawater or reclaimed water to re-adsorb or deposit on the cathode surface, restoring the negative charge density of the negatively charged surface layer, effectively inhibiting the scaling process on the cathode surface, and ensuring the long-term, efficient, and stable operation of the electrolysis reaction.

Description

Technical Field

[0001] This application relates to the field of electrolytic hydrogen production technology, and more specifically, to a method and system for controlling the electrolytic hydrogen production process based on infrasound-assisted anti-fouling. Background Technology

[0002] Against the backdrop of the current global energy transition, direct electrolysis of seawater or reclaimed water to produce hydrogen is considered a highly promising clean energy production method. However, this technology faces a core and severe technical challenge in practical applications: electrode scaling. Seawater or reclaimed water typically contains high concentrations of hardness ions such as magnesium and calcium ions. During hydrogen electrolysis, a hydrogen evolution reaction occurs on the cathode surface, consuming water molecules and generating hydroxide ions. This leads to a significant increase in pH value in the liquid layer near the electrode, i.e., the diffusion layer, creating a locally highly alkaline microenvironment. This increased pH value promotes the combination of magnesium and calcium ions with hydroxide ions in the solution, forming insoluble precipitates such as magnesium hydroxide and calcium carbonate. These precipitates preferentially nucleate heterogeneously on the cathode surface and grow rapidly, eventually covering the active sites of the electrode, forming a dense, insulating scale layer. This scale layer severely hinders charge transfer between the electrode and the electrolyte, significantly increasing the overpotential during electrolysis, leading to a sharp decline in electrolysis efficiency, a significant increase in energy consumption, and in severe cases, even paralyzing the entire hydrogen production system due to electrode passivation. Traditional solutions, such as expensive desalination pretreatment of seawater before electrolysis or the addition of chemical scale inhibitors to the electrolyte, often suffer from problems such as system complexity, high energy consumption, huge investment, or the introduction of secondary pollution, which limit the economic efficiency and environmental friendliness of direct seawater hydrogen production technology.

[0003] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application provides a method and system for controlling the electrolytic hydrogen production process based on infrasound-assisted anti-scaling, which can solve the technical problems of severe cathode scaling, low electrolysis efficiency, and unstable operation caused by the presence of hardness ions when directly using seawater or reclaimed water to produce hydrogen.

[0005] In a first aspect, this application provides a method for controlling an electrolytic hydrogen production process based on infrasound-assisted anti-scaling, comprising: Hydrogen production by electrolysis of seawater or reclaimed water is carried out in the electrolysis zone using a cathode with a negatively charged surface modification layer. In the electrolytic hydrogen production reaction, infrasound of a preset frequency is applied to the electrolysis zone and its circulation pipeline system to disrupt the fluid boundary layer and peel off the attached substances. The temperature of seawater or reclaimed water entering the electrolysis zone is controlled by thermal energy regulation to ensure that the temperature reaches the preset electrolysis temperature range. In the electrolytic hydrogen production reaction, an alternating current signal is periodically applied to the cathode, and the functional state of the negative charge modification layer is judged based on the measured electrochemical impedance characteristics of the cathode surface to determine whether the preset repair conditions are met. When the functional state meets the preset repair conditions, an electrochemical pulse is applied to the cathode to guide the iodine-containing components in seawater or reclaimed water to be re-adsorbed or deposited on the cathode surface, thereby restoring the negative charge density of the negative charge modification layer.

[0006] This technical solution constructs a multi-synergistic anti-scaling system that integrates electrostatic repulsion, mechanical stripping, and online self-repair. It can effectively suppress the scaling process on the cathode surface without expensive pretreatment, ensuring the long-term, efficient, and stable operation of the electrolysis reaction.

[0007] Furthermore, before the electrolytic hydrogen production reaction begins, it also includes: Filtering seawater or reclaimed water to remove particulate impurities; In the transport path of seawater or reclaimed water before it enters the electrolysis zone, infrasound of a preset frequency is applied for pre-intervention to disrupt the orderly arrangement of ions in the seawater or reclaimed water and reduce the crystallization activity of ions.

[0008] This technical solution pretreats scale-forming ions before the electrolysis reaction occurs. Through the cavitation effect of infrasound and mechanical vibration, the crystallization tendency of scale-forming ions is reduced from the source, further enhancing the overall anti-scaling effect.

[0009] Furthermore, the steps of using a cathode with a negatively charged surface modification layer to perform the electrolytic hydrogen production reaction of seawater or reclaimed water in the electrolysis zone include: Iodine ions are introduced onto the cathode surface to construct an iodine-modified layer, which serves as a negative charge modification layer.

[0010] Furthermore, the step of applying infrasound of a preset frequency to the electrolysis zone and its circulation pipeline system includes: Infrasound of a preset frequency is applied by using an infrasound generator array with a transmission frequency of 5-20Hz and adjustable sound pressure level, which is set in the electrolysis area and its circulation pipeline system. The preset frequency for infrasound is 12Hz.

[0011] This technical solution provides specific engineering parameters for the application of infrasound. By selecting specific low-frequency infrasound, strong stirring and shearing effects can be generated on the fluid on a macroscopic scale, effectively destroying the concentration boundary layer. At the same time, its energy is sufficient to remove tiny scale crystals, but not enough to damage precision components such as electrodes or diaphragms, thus achieving a balance between efficient scale removal and system safety.

[0012] Furthermore, the steps of thermally regulating the seawater or reclaimed water entering the electrolysis zone to bring its temperature to a preset electrolysis temperature range include: External industrial waste heat is introduced as a heat source, and the industrial waste heat is exchanged with seawater or reclaimed water to bring the temperature of the seawater or reclaimed water to a preset electrolysis temperature range; the preset electrolysis temperature range is 60 degrees Celsius to 80 degrees Celsius.

[0013] This technical solution not only reduces energy consumption and increases reaction kinetics by raising the temperature, but also cleverly utilizes industrial waste heat, significantly reducing system operating costs and improving overall energy efficiency and economy. Simultaneously, the selected temperature range also helps regulate salt solubility and synergistically inhibits scaling.

[0014] Furthermore, the steps for determining whether the functional state of the negative charge modification layer meets the preset repair conditions based on the measured electrochemical impedance characteristics of the cathode surface include: When the electrochemical impedance characteristic exceeds the first preset threshold and the reaction time of the electrolytic hydrogen production reaction reaches the preset maintenance time interval, the functional status is determined to meet the preset repair conditions.

[0015] This technical solution establishes a more precise repair triggering mechanism based on dual conditions. It combines impedance parameters that reflect the current true state of the electrode with an experience-based periodic maintenance strategy, avoiding premature or late repairs caused by misjudgment of a single condition, and ensuring the timeliness and necessity of repair operations.

[0016] Furthermore, the step of applying an electrochemical pulse to the cathode includes: The frequency of the infrasound is switched from a preset frequency to a preset repair guidance frequency, which is used to form a sound pressure standing wave field on the cathode surface. An electrochemical pulse is applied in an infrasonic environment at a preset repair guidance frequency and for a preset duration. The acoustic radiation force generated by the acoustic pressure standing wave field and the electric field force generated by the electrochemical pulse work together to guide the iodine-containing components in seawater or reclaimed water to be directionally enriched and deposited on the cathode surface.

[0017] By constructing a specific acoustic pressure standing wave field, the repair components in the solution are captured and attached to the electrode surface by acoustic radiation force. In synergy with the electric field force, the repair efficiency and quality are greatly improved, and rapid and precise targeted repair is achieved.

[0018] Furthermore, the electrolytic hydrogen production reaction also includes: Real-time monitoring of the input current density of the electrolytic hydrogen production reaction, and acquisition of the fluctuation parameters of the input current density; When the input current density increases and the fluctuation parameter exceeds the second preset threshold, the frequency of the infrasound is increased, and the temperature of the seawater or reclaimed water is adjusted simultaneously to control the temperature fluctuation range of the electrolyte within ±2 degrees Celsius.

[0019] This technical solution introduces a dynamic feedback adjustment mechanism based on real-time operating conditions, enabling the system to intelligently respond to load changes. Under high current density, by actively enhancing infrasound intensity and precisely controlling temperature, the risk of scaling, which may be exacerbated by intense gas production and localized temperature rise, is effectively suppressed, improving the system's adaptability and robustness over a wide range of operating conditions.

[0020] Furthermore, after the electrolytic hydrogen production reaction, the process also includes: Physical separation treatment is carried out on seawater or reclaimed water containing sediment; The heat generated by the electrolytic hydrogen production reaction or the introduction of external industrial waste heat is used to evaporate and concentrate the separated seawater or reclaimed water to co-produce fresh water and high-concentration brine.

[0021] This technological solution extends the process to downstream treatment, enabling resource recycling and maximizing value. By co-producing freshwater and high-concentration brine, it not only solves the wastewater treatment problem but also creates additional economic value, making the entire hydrogen production process greener and more sustainable.

[0022] Secondly, this application also discloses a hydrogen production process control system based on infrasound-assisted scale inhibition, used to execute the hydrogen production process control method based on infrasound-assisted scale inhibition as described in any of the preceding claims. The system includes: The cathode reaction module is used to carry out the electrolysis of seawater or reclaimed water to produce hydrogen in the electrolysis zone using a cathode with a negatively charged surface modification layer. The mechanical vibration module is used to apply infrasound waves of a preset frequency to the electrolysis zone and its circulation pipeline system in the electrolysis hydrogen production reaction, so as to destroy the fluid boundary layer and peel off the attached substances. The thermal energy control module is used to regulate the thermal energy of seawater or reclaimed water entering the electrolysis zone so that its temperature reaches the preset electrolysis temperature range. The monitoring module is used to periodically apply an alternating current signal to the cathode during the electrolytic hydrogen production reaction, and determine whether the functional state of the negative charge modification layer meets the preset repair conditions based on the measured electrochemical impedance characteristics of the cathode surface. The repair control module is used to apply an electrochemical pulse to the cathode when the functional state meets the preset repair conditions, so as to guide the iodine-containing components in seawater or reclaimed water to be re-adsorbed or deposited on the cathode surface, thereby restoring the negative charge density of the negative charge modification layer.

[0023] The technical solution provided in this application achieves significant beneficial effects by constructing a synergistic anti-scaling strategy that incorporates electrostatic repulsion, mechanical vibration, and online repair mechanisms. First, by constructing a negatively charged modification layer on the cathode surface, the principle of like charge repulsion effectively prevents positively charged scale-forming cations such as calcium and magnesium from approaching the electrode surface at the microscopic level, thus inhibiting scale nucleation at its source. Second, the introduction of infrasound waves of a specific frequency applies continuous mechanical disturbance to the electrolysis zone and piping system. This disturbance effectively disrupts the ion concentration boundary layer on the electrode surface, preventing excessively high local pH values, and simultaneously removes existing microscale crystals or deposits, thus achieving a physical cleaning effect. Most importantly, this application proposes a closed-loop control logic for online monitoring and self-repair. This logic can sense the state of the protective layer in real time and, when its function declines, guide specific components in the solution through electrochemical pulses to complete in-situ repair of the protective layer, greatly extending the effective working life of the electrode and the continuous operation time of the system. This multi-pronged synergistic effect enables the system to achieve long-term, stable, and efficient direct electrolysis of seawater or reclaimed water to produce hydrogen without relying on expensive seawater desalination pretreatment or the addition of chemical scale inhibitors. This significantly reduces hydrogen production costs and environmental pollution, providing a reliable and economical technical path for large-scale utilization of marine resources to produce green hydrogen. Attached Figure Description

[0024] Figure 1 This is a schematic flowchart of a method for controlling the electrolytic hydrogen production process based on infrasound-assisted anti-fouling, provided in an embodiment of this application.

[0025] Figure 2 This is a schematic diagram of a control system for an electrolytic hydrogen production process based on infrasound-assisted anti-fouling, provided in an embodiment of this application.

[0026] Labeling Explanation: 210, Cathode Reaction Module; 220, Mechanical Vibration Module; 230, Thermal Energy Control Module; 240, Monitoring Module; 250, Repair Control Module. Detailed Implementation

[0027] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0028] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] At a large-scale green hydrogen production base built along the coast, the plan was to directly utilize the inexhaustible seawater from the nearby waters as raw material to produce hydrogen through a large-scale array of electrolyzers. However, during the trial operation phase, a serious problem quickly emerged: after less than a few dozen hours of continuous operation, a layer of white, scale-like hard deposits would adhere to the cathode surface of the electrolyzers. Analysis revealed that these deposits were mainly magnesium hydroxide and calcium carbonate. The formation of this scale layer caused the voltage required for electrolysis to continuously rise, hydrogen production efficiency to decrease at a visible rate, and the energy consumption of the entire system to increase dramatically. To maintain production, the plant had to frequently interrupt the electrolysis process to acid-wash and descale the electrolyzers. This not only brought a huge amount of maintenance work and lost production time, but also created new environmental pressures and cost burdens due to the treatment of acid washing wastewater. This system instability and high operation and maintenance costs caused by cathode scaling have become a major obstacle to the commercial application of direct seawater hydrogen production technology.

[0030] Regarding this, firstly, see... Figure 1 This application proposes a method for controlling the electrolytic hydrogen production process based on infrasound-assisted anti-scaling, the method comprising: S1. Hydrogen production by electrolysis of seawater or reclaimed water is carried out in the electrolysis zone using a cathode with a negative charge modification layer on its surface. S2. In the electrolytic hydrogen production reaction, infrasound of a preset frequency is applied to the electrolysis zone and its circulation pipeline system to disrupt the fluid boundary layer and peel off the attached substances. S3. Perform thermal energy regulation on the seawater or reclaimed water entering the electrolysis zone to bring its temperature to the preset electrolysis temperature range. S4. In the electrolytic hydrogen production reaction, an alternating current signal is periodically applied to the cathode, and the functional state of the negative charge modification layer is judged based on the measured electrochemical impedance characteristics of the cathode surface to determine whether the preset repair conditions are met. S5. When the functional state meets the preset repair conditions, an electrochemical pulse is applied to the cathode to guide the iodine-containing components in seawater or reclaimed water to be re-adsorbed or deposited on the cathode surface, thereby restoring the negative charge density of the negative charge modification layer.

[0031] The negative charge modification layer refers to a surface functional layer with a net negative charge constructed on the surface of the cathode material used in the hydrogen evolution reaction through physical adsorption, chemical bonding, or electrochemical deposition. Iodine modification can be used, and the cathode material can be nickel-based or platinum-based metals. The cathode environment of seawater electrolysis is strongly alkaline, with a high potential gradient and accompanied by intense hydrogen evolution. Many organic polymer coatings are prone to hydrolysis, swelling, or peeling under such conditions. Iodine, however, can form very stable chemical adsorption or chemical bonds with nickel-based or platinum-based noble metal substrates, typically maintaining structural and functional integrity under harsh electrolysis conditions for extended periods. Iodine modification can be conveniently and uniformly achieved on porous electrode surfaces with complex morphologies through electrochemical deposition or chemical immersion adsorption methods. The process is generally simple, cost-effective, and easy to scale up for mass production.

[0032] Electrochemical impedance spectroscopy (EIS) is a set of parameters used to characterize the kinetics of electrochemical processes at the electrode / electrolyte interface. By applying a small alternating current or potential disturbance to the electrode system and measuring its response, impedance information at different frequencies can be obtained. This information is typically expressed in complex form and can be plotted as a Nyquist plot or a Bode plot. Specifically, charge transfer resistance, related to charge transfer processes, and double-layer capacitance, related to the electric double layer, are concrete manifestations of EIS. When fouling occurs on the electrode surface, the insulating fouling layer significantly hinders charge transfer, leading to a significant increase in charge transfer resistance. This change can be precisely measured, thus serving as a basis for judging the state of the electrode surface.

[0033] An electrochemical pulse refers to a non-steady-state electrical signal application method, where the voltage or current is not a constant value but changes rapidly within a short period of time according to a preset waveform and timing sequence. For example, it can be one or more square wave pulses, triangular wave pulses, or more complex combinations of waveforms. By precisely designing the pulse's amplitude, width, duty cycle, and frequency, the potential at the electrode surface can be instantaneously controlled to a specific numerical range to drive specific electrochemical reactions, such as the selective adsorption, desorption, or deposition of specific ions, without causing lasting interference to the entire electrolysis system.

[0034] In a specific embodiment, the overall process of the above control method is described in detail.

[0035] The entire process takes place in a large-scale industrial-grade alkaline electrolyzer system, which has been modified to accommodate direct seawater electrolysis. The cathode uses nickel foam with a high specific surface area, while the anode uses a ruthenium-iridium coated titanium mesh.

[0036] First, before the electrolytic hydrogen production reaction begins, the cathode needs to be pretreated to construct an initial negative charge modification layer. One feasible pretreatment method is to immerse the virgin nickel foam cathode in a solution containing specific anions, such as sodium polystyrene sulfonate (PSS). PSS is a polymer electrolyte with a large number of negative charges, which can form a stable negative charge modification layer on the surface of the nickel foam through physical adsorption. After pretreatment, the cathode is installed in the electrolytic cell.

[0037] The system then begins operation. Seawater, after initial filtration to remove larger suspended solids and silt, is pumped into the system's circulation pipeline. Before entering the electrolyzer, the seawater first flows through a heat exchange unit. This unit is connected to other high-temperature equipment within the plant (such as air compressor cooling systems or flue gas waste heat recovery systems), utilizing the industrial waste heat generated by these devices to heat the seawater. A temperature sensor monitors the temperature of the heated seawater in real time, and a PID controller adjusts the flow rate of the heat exchange medium to ensure that the temperature of the seawater entering the electrolyzer remains stable within the preset electrolysis temperature range.

[0038] Seawater carrying thermal energy enters the electrolysis zone of the electrolyzer. At this time, an array of infrasound generators, rigidly connected to the outside of the electrolyzer and circulation pipeline, begins to operate. These generators are uniformly driven by a central controller, applying a low-frequency, high-amplitude mechanical vibration to the entire liquid system. This vibration propagates in the liquid as infrasound, and its energy is sufficient to agitate the liquid on a macroscopic scale, especially in areas where fluids are prone to stagnation, such as electrode surfaces, near diaphragms, and pipe bends, creating strong turbulence and shear forces. This mechanical action effectively breaks down the static concentration boundary layer formed on the cathode surface due to the hydrogen evolution reaction, rapidly carrying the enriched hydroxide ions into the mainstream solution and preventing excessive increases in local pH. On the other hand, for those tiny scale crystals that manage to penetrate the electrostatic repulsion field of the negatively charged modification layer and form on the electrode surface, the continuous impact of the infrasound can break them up and peel them off like a miniature hammer, preventing them from growing and accumulating further.

[0039] While direct current is applied for hydrogen electrolysis, an independent monitoring unit begins to operate periodically. For example, every hour, the main electrolysis power supply pauses for one second. During this one-second interval, the monitoring unit applies a sinusoidal AC voltage signal with an amplitude of 10 millivolts, containing multiple frequency components, to the cathode via a function generator, and records the corresponding current response using a high-precision current acquisition card. Through algorithms such as Fourier transform, the controller can quickly calculate the electrochemical impedance spectrum of the cathode under the current state and extract the key charge transfer resistance value.

[0040] The controller internally stores an initial, clean-state charge transfer resistance reference value. During operation, the controller continuously compares the latest measured resistance value with the reference value. When the controller determines that the functional state of the negative charge modification layer meets preset repair conditions, for example, when the measured charge transfer resistance value exceeds 1.5 times the reference value and the system has been running continuously for more than 100 hours, the repair procedure will be automatically triggered.

[0041] After the repair procedure is initiated, the main electrolysis power supply remains off. An electrochemical pulse generator is connected to both the cathode and anode. This generator applies a series of carefully designed negative voltage pulses to the cathode. The amplitude and width of these pulses are optimized to instantaneously adjust the cathode's surface potential to a potential window that strongly adsorbs naturally occurring iodine-containing components (mainly iodide ions) in seawater. Under the influence of the pulsed electric field, iodide ions in the solution are driven to preferentially re-adsorb or undergo trace deposition at active sites on the cathode surface, thereby rapidly replenishing and repairing the damaged or detached negative charge modification layer, restoring its negative charge density to its initial level. The entire repair process may only last a few minutes. After the repair is complete, the system automatically switches back to normal electrolytic hydrogen production mode.

[0042] Through the aforementioned series of synergistic steps, this method can achieve long-term and effective suppression of cathode scaling without interrupting the main production process. The negative charge modification layer acts as the first line of defense, preventing scale-forming ions from approaching at the source; infrasound acts as the second line of defense, continuously performing physical cleaning and environmental improvement; while the online monitoring and self-healing mechanism functions like an intelligent maintenance system, ensuring the enduring effectiveness of the first line of defense. This multi-layered protection system greatly enhances the stability and economics of directly utilizing seawater for hydrogen electrolysis.

[0043] Furthermore, before the electrolytic hydrogen production reaction begins, it also includes: Filtering seawater or reclaimed water to remove particulate impurities; In the transport path of seawater or reclaimed water before it enters the electrolysis zone, infrasound of a preset frequency is applied for pre-intervention to disrupt the orderly arrangement of ions in the seawater or reclaimed water and reduce the crystallization activity of ions.

[0044] In practice, the filtration of seawater or reclaimed water can employ industrially mature multi-media filters or microfiltration membrane systems. Their main purpose is to remove suspended particles such as silt, algae, and organic debris from seawater. These particles can not only clog pipes and electrolyzer channels, but more importantly, they can act as nuclei for heterogeneous crystal formation, significantly inducing and accelerating the precipitation of scale such as magnesium hydroxide and calcium carbonate. Effective filtration can eliminate a large number of potential nucleation sites.

[0045] A more crucial step is infrasound pre-intervention. A separate infrasound intervention section is installed on the pipeline leading to the filtered seawater before it enters the heat exchanger and electrolyzer. An infrasound transducer is also installed on the outside of this section. As the seawater flows through this area, the mechanical energy of the infrasound acts on the ions in the solution. The principle is that even in unsaturated or slightly supersaturated solutions, scale-forming cations (such as Mg2+, Ca2+) and anions (such as OH-, CO32-) are not completely randomly distributed, but tend to form dynamic, short-range ordered ion associations or pre-nucleated clusters. These clusters are precursors to crystal nucleation. The low-frequency, high-energy mechanical vibrations provided by infrasound effectively break down these unstable ordered structures, forcing the ions back to a disordered solvated state. This thermodynamically increases the activation energy barrier required for nucleation, thus reducing the crystallization activity of the ions. Even if the seawater undergoes this pre-intervention treatment encounters a localized high pH environment on the cathode surface, the tendency and rate of heterogeneous nucleation are significantly weakened, creating more favorable conditions for subsequent anti-scaling measures such as electrostatic repulsion and mechanical stripping, thus playing a synergistic role in preventing problems before they occur.

[0046] In a more preferred embodiment, the step of performing the electrolytic hydrogen production reaction of seawater or reclaimed water in the electrolysis zone using a cathode with a negatively charged surface modification layer includes: Iodine ions are introduced onto the cathode surface to construct an iodine-modified layer, which serves as a negative charge modification layer.

[0047] Specifically, choosing iodide ions as the core component for constructing the negatively charged modification layer has unique advantages. Seawater naturally contains trace amounts of iodide ions (typically at a concentration of 50-60 micrograms per liter), which provides a material basis for achieving in-situ, low-cost construction and repair of the modification layer. Iodide ions have a large ionic radius and strong deformability, making them highly susceptible to strong physical or chemical adsorption on various metal surfaces.

[0048] In practice, initial modification of the cathode can be achieved by immersing a nickel foam electrode in a solution containing a slightly higher concentration of potassium iodide (e.g., 0.01 mol / L) and applying a weak anodic potential (approximately -0.2 V relative to a saturated calomel electrode) for several minutes to induce electrochemical adsorption, forming a dense iodide ion adsorption layer on the electrode surface. The iodide ions in this iodine-modified layer face the solution with their negatively charged ends, thus constructing a stable and effective electrostatic shield on the electrode surface. When this iodine-modified layer partially peels off or its coverage decreases due to long-term operation, the electrochemical pulse applied in the repair step can directly utilize the naturally occurring iodide ions in seawater to guide them to re-adsorb onto the exposed electrode sites, achieving self-healing of the modified layer. Iodide ions are chosen because their adsorption behavior is relatively controllable and they do not introduce other impurities harmful to the electrolysis reaction.

[0049] In a preferred embodiment, the step of applying infrasound of a preset frequency to the electrolysis zone and its circulation pipeline system includes: Infrasound of a preset frequency is applied by using an infrasound generator array with a transmission frequency of 5-20 Hz and adjustable sound pressure level, which is set in the electrolysis area and its circulation pipeline system. The preset frequency for infrasound is 12 Hz.

[0050] The selection of the specific infrasound frequency band of 5-20 Hz is based on a deep understanding of the interaction between sound waves and fluids and solid structures. Unlike conventional ultrasonic waves used for cleaning (which typically have frequencies above 20 kHz), infrasound has a very long wavelength. Its mechanism of action does not primarily rely on the bursting of tiny bubbles generated by cavitation effects, but rather on generating large-amplitude, low-frequency reciprocating motions and pressure fluctuations throughout the fluid volume. This macroscopic mechanical disturbance is particularly effective at disrupting the diffusion layer, which is several micrometers to hundreds of micrometers thick, on the electrode surface.

[0051] In this embodiment, the preset frequency is precisely set to 12 Hz. This value is not arbitrarily chosen, but rather an optimal value obtained through experiments and simulations. Studies have found that for typical industrial electrolyzer structures, a vibration frequency of 12 Hz easily induces resonance or standing waves within the electrolyte chamber, resulting in the highest efficiency of acoustic energy utilization and generating maximum fluid shear stress on the electrode surface with minimal electrical energy consumption. If the frequency is too low (e.g., below 5 Hz), the vibration is too slow, and the destructive effect on the boundary layer is not significant; if the frequency is too high (e.g., close to 20 Hz), the wavelength becomes shorter, and the energy is more easily absorbed and attenuated by the liquid, making it difficult to act on the entire electrolyzer and potentially causing unnecessary mechanical fatigue to precision components such as electrodes and diaphragms.

[0052] In practice, the infrasound generating array consists of multiple high-power electromagnetic vibrators, which are fixed to the outer wall of the electrolytic cell and the outside of the main circulation pipeline. A central signal generator produces a 12 Hz sinusoidal electrical signal, which, after power amplification, drives these vibrators to operate synchronously. Furthermore, the adjustable sound pressure level is crucial, allowing the system to dynamically adjust the infrasound intensity according to operating conditions (such as current density), achieving on-demand energy distribution.

[0053] In a more preferred embodiment, the step of thermally regulating the seawater or reclaimed water entering the electrolysis zone to bring its temperature to a preset electrolysis temperature range includes: External industrial waste heat is introduced as a heat source, and the industrial waste heat is exchanged with seawater or reclaimed water to bring the temperature of the seawater or reclaimed water to a preset electrolysis temperature range; the preset electrolysis temperature range is 60 degrees Celsius to 80 degrees Celsius.

[0054] Setting the electrolysis temperature within the range of 60 to 80 degrees Celsius is a result of comprehensive consideration of factors such as electrochemical reaction kinetics, ion solubility, and energy economy. Firstly, from an electrochemical perspective, increasing the temperature significantly reduces the overpotential of water electrolysis, meaning a lower driving voltage is required at the same current density, which translates to a direct reduction in energy consumption. Within this temperature range, the rates of both hydrogen evolution and oxygen evolution reactions are greatly accelerated.

[0055] Secondly, from the perspective of inhibiting scaling, temperature control also plays a subtle role. Although increasing the temperature accelerates all chemical reactions, including scaling reactions, the technical solution of this application has effectively inhibited scaling through electrostatic repulsion and mechanical stripping. At the same time, controlling the temperature below 80 degrees Celsius can effectively prevent certain salts (such as calcium sulfate) from experiencing a decrease in solubility due to excessively high temperatures (i.e., the so-called reverse solubility), thereby preventing new scaling problems from occurring in the high-temperature areas of heat exchangers or pipelines.

[0056] Most importantly, this step emphasizes the use of industrial waste heat as a heat source. In large chemical industrial parks or power plants, there is a large amount of low-grade waste heat (such as hot water or low-pressure steam at 60-100 degrees Celsius), which is often directly discharged into the environment. This solution uses a plate or shell-and-tube heat exchanger to transfer the energy of this waste heat to the cold seawater entering the electrolysis system, achieving cascaded energy utilization. For example, 70-degree Celsius warm water discharged from a nearby thermal power plant's cooling tower can be used to preheat 15-degree Celsius seawater to 65-degree Celsius. This design not only provides the optimal operating temperature for the electrolysis process but also adds almost no additional energy costs, significantly improving the overall energy efficiency and economic feasibility of the entire hydrogen production process.

[0057] In a preferred embodiment, the step of determining whether the functional state of the negative charge modification layer meets the preset repair conditions based on the measured electrochemical impedance characteristics of the cathode surface includes: When the electrochemical impedance characteristic exceeds the first preset threshold and the reaction time of the electrolytic hydrogen production reaction reaches the preset maintenance time interval, the functional status is determined to meet the preset repair conditions.

[0058] Relying solely on electrochemical impedance characteristics as a basis for judgment may lead to misjudgment. For example, during electrolysis, a large hydrogen bubble may temporarily adhere to a localized area of ​​the electrochemical probe or cathode, causing a sudden spike in the measured impedance. If this is used as the sole basis for triggering repairs, it could cause unnecessary production interruptions.

[0059] Relying solely on reaction time as the maintenance cycle is too rigid and inefficient. The wear rate of the protective layer on the electrode surface is closely related to actual operating conditions, such as current density and fluctuations in seawater quality. Under low load operation, the protective layer may remain in good condition for a long time; however, under high load, its degradation may accelerate. Using fixed time intervals for repair is either too frequent, leading to waste, or the intervals are too long, resulting in repairs only after the protective layer has failed, by which time scaling may have already occurred.

[0060] The dual-condition judgment mechanism proposed in this embodiment cleverly combines the advantages of both. The preset maintenance interval, for example, set to 100 hours, acts as a safety gate or filter. That is, during the first 100 hours of system operation, even if impedance fluctuations occur, the controller recognizes them as short-term disturbances and does not initiate the repair procedure. This effectively filters out false positive signals caused by factors such as bubbles and transient electrical signal interference.

[0061] After more than 100 hours of operation, this safety gate opens, and the controller begins to seriously monitor impedance changes. At this point, it continuously monitors electrochemical impedance characteristics (such as charge transfer resistance). Once this value exceeds a preset first threshold (e.g., set at 1.8 times the initial clean electrode resistance), the controller immediately determines that the repair conditions have been met and initiates the repair process. This combination of time threshold and state threshold logic ensures that repair operations are triggered only when truly necessary, achieving precise management of the system state and optimized resource utilization.

[0062] Furthermore, the step of applying an electrochemical pulse to the cathode includes: The frequency of the infrasound is switched from a preset frequency to a preset repair guidance frequency, which is used to form a sound pressure standing wave field on the cathode surface. An electrochemical pulse is applied in an infrasonic environment at a preset repair guidance frequency and for a preset duration. The acoustic radiation force generated by the acoustic pressure standing wave field and the electric field force generated by the electrochemical pulse work together to guide the iodine-containing components in seawater or reclaimed water to be directionally enriched and deposited on the cathode surface.

[0063] This step is a refined and efficient improvement to the online repair process of the cathodic protection layer. Its core lies in utilizing the synergistic effect of the acoustic field and the electric field to achieve targeted transport of the repair components.

[0064] In a specific embodiment, when the system triggers the repair procedure, the control system performs the following coordinated operations: First, the drive signal frequency of the infrasound generator switches from the normal operating frequency of 12 Hz to a pre-calculated repair guidance frequency, such as 18.5 Hz. This frequency is one of the resonant frequencies precisely calculated based on the geometry of the electrolytic cell (such as the distance between the anode and cathode, the height of the cavity, etc.). At this frequency, the infrasound waves will interfere as they propagate in the electrolyte, forming a stable sound pressure standing wave field. This standing wave field has spatially fixed pressure nodes (minimum sound pressure) and antinodes (maximum sound pressure) regions.

[0065] According to acoustic theory, particles suspended in a fluid (here, these can be considered as solvated iodine-containing components, such as iodide ions) experience a nonlinear acoustic effect force called acoustic radiation force in a sound pressure standing wave field. The direction and magnitude of this force depend on the difference in density and compressibility between the particles and the fluid. Through precise design, the iodine-containing components can be captured and propelled towards the sound pressure antinodes under the influence of the acoustic radiation force. By adjusting the standing wave field, these antinodes can be positioned precisely near the active region on the cathode surface.

[0066] While the acoustic field enriches the iodine-containing components near the cathode, the electrochemical pulse generator applies a repair pulse to the cathode. At this point, because the concentration of iodine-containing components near the cathode surface is already several orders of magnitude higher than in the mainstream solution, the electric field generated by the electrochemical pulse can drive the already pre-deployed repair materials to complete the adsorption or deposition process with extremely high efficiency. This synergistic mechanism of acoustic field enrichment and electric field deposition acts like a microscopic robotic arm, precisely transporting the necessary repair materials to the wall requiring repair, and then fixing them with electrochemical cement. Compared to relying solely on electric field force to search for and attract repair components in a vast solution, this synergistic approach results in faster repair speeds, more uniform and dense repair layers, and higher utilization of repair materials, enabling higher-quality repairs with shorter downtime.

[0067] Furthermore, the electrolytic hydrogen production reaction also includes: Real-time monitoring of the input current density of the electrolytic hydrogen production reaction, and acquisition of the fluctuation parameters of the input current density; When the input current density increases and the fluctuation parameter exceeds the second preset threshold, the frequency of the infrasound is increased, and the temperature of the seawater or reclaimed water is adjusted simultaneously to control the temperature fluctuation range of the electrolyte within ±2 degrees Celsius.

[0068] This step introduces a smart feedback adjustment mechanism based on real-time operating conditions to address the changes in electrolytic load caused by the volatility of renewable energy (such as wind and solar) power generation.

[0069] In a practical application scenario, when sunlight intensifies at midday or winds increase at night, the electrical energy input to the electrolysis system increases significantly, requiring the system to operate at a higher current density to absorb this energy. High current density implies a more vigorous hydrogen evolution reaction, resulting in a sharp increase in the number and volume of hydrogen bubbles generated on the cathode surface per unit time. Simultaneously, ohmic heat (Joule heat) generation also intensifies. These changes present new challenges: a large number of bubbles may aggregate and cover the electrodes, forming gas barriers that hinder the contact between the electrolyte and the electrodes, causing a sharp spike in local pH and exacerbating the risk of scaling; simultaneously, a rapid rise in local temperature may lead to thermal imbalance in the system.

[0070] In this embodiment, the control system monitors the total input current in real time using a high-frequency current sensor. The controller not only focuses on the absolute value of the current but also obtains fluctuation parameters by calculating its standard deviation or rate of change within a short time window. When the current density exceeds a high-load threshold (e.g., 80% of the rated current) and its fluctuation parameters also exceed a second preset threshold (indicating that the system has entered a high-load and unstable operating state), the dynamic adjustment program is activated.

[0071] Once the program is activated, the controller issues two commands: First, it raises the frequency of the infrasound from the conventional 12 Hz to a higher frequency, such as 16 Hz. Higher frequency vibrations mean a faster shear rate, which is more effective at quickly and efficiently removing the numerous, more adhesive microbubbles generated under high current density from the electrode surface, thus maintaining good liquid-solid contact. Second, it sends commands to the thermal control module to enhance thermal management. For example, by increasing the flow rate of the cooling medium through the heat exchanger or activating the backup cooling unit, it actively removes the extra heat generated during electrolysis, ensuring that the bulk temperature of the entire electrolyte is strictly controlled within ±2 degrees Celsius of the target value (e.g., 70 degrees Celsius). This proactive and synchronous acoustic and thermal synergistic control ensures that the system maintains efficient and stable anti-fouling performance and safe thermal conditions even when dealing with high and fluctuating energy inputs.

[0072] Furthermore, after the electrolytic hydrogen production reaction, the process also includes: Physical separation treatment is carried out on seawater or reclaimed water containing sediment; The heat generated by the electrolytic hydrogen production reaction or the introduction of external industrial waste heat is used to evaporate and concentrate the separated seawater or reclaimed water to co-produce fresh water and high-concentration brine.

[0073] This step extends the technical solution of this application from simple hydrogen production process control to the closed-loop utilization and value maximization of the entire material flow, reflecting the design concept of circular economy.

[0074] Although most of the scale in the seawater discharged from the electrolyzer is contained outside the electrode surface, it still contains a small amount of tiny suspended precipitate particles (mainly magnesium hydroxide and calcium carbonate) that have been stripped away by infrasound. Before entering subsequent treatment units, this water flow first passes through a settling tank or plate clarifier. Under the influence of gravity, these denser solid particles settle to the bottom, forming sludge, which is periodically discharged. After dewatering and drying, this sludge can be sold as an industrial raw material (such as for the production of flame retardants or building materials).

[0075] The seawater, after physical separation and becoming clearer, has a slightly higher salinity compared to the inlet seawater. This flow is pumped into a multi-effect evaporator (MED) or mechanical vapor recompression (MVR) unit. The heat energy required for these efficient evaporation technologies primarily comes from the waste heat generated by the electrolysis process itself. Large electrolyzers generate a large amount of heat during operation, which can be removed by cooling circulating water at a temperature suitable for use as a heat source for the evaporator. If the waste heat itself is insufficient, the aforementioned external industrial waste heat can be utilized as supplementary heat.

[0076] In the evaporator, seawater is heated to boiling, and the resulting steam is condensed to obtain high-quality freshwater, which can be used for replenishing the electrolyzer itself, for production and daily life in the surrounding community, or sold directly as a commodity. The unevaporated seawater is continuously concentrated, eventually forming high-concentration brine. This high-concentration brine is a valuable chemical raw material, which can be directly supplied to the chlor-alkali industry for the production of chlorine and caustic soda, or used to extract high-value-added elements such as bromine, lithium, and magnesium.

[0077] Through this series of back-end treatments, the electrolysis tail liquid, which might otherwise be considered wastewater, is transformed into two valuable products: freshwater and high-concentration brine, achieving the dual utilization of water and salt resources in seawater. This not only solves the environmental problem of wastewater discharge but also creates additional economic benefits through co-production, significantly improving the overall economic efficiency and sustainability of the entire seawater direct electrolysis hydrogen production project.

[0078] Secondly, see Figure 2 This application also provides a control system for electrolytic hydrogen production process based on infrasound synergistic anti-scaling. This system is the physical embodiment for the engineering implementation of the aforementioned method. Its structure and functional design closely revolve around the core idea of ​​synergistic anti-scaling. The system includes: The cathode reaction module 210 is used to carry out the electrolytic hydrogen production reaction of seawater or reclaimed water in the electrolysis zone using a cathode with a negative charge modification layer on its surface. Mechanical vibration module 220 is used to apply infrasound of a preset frequency to the electrolysis zone and its circulation pipeline system in the electrolysis hydrogen production reaction, so as to destroy the fluid boundary layer and peel off the attached substances. The thermal energy control module 230 is used to regulate the thermal energy of seawater or reclaimed water entering the electrolysis zone so that its temperature reaches the preset electrolysis temperature range. The monitoring module 240 is used to periodically apply an alternating current signal to the cathode during the electrolytic hydrogen production reaction, and to determine whether the functional state of the negative charge modification layer meets the preset repair conditions based on the measured electrochemical impedance characteristics of the cathode surface. The repair control module 250 is used to apply an electrochemical pulse to the cathode when the functional state is determined to meet the preset repair conditions, so as to guide the iodine-containing components in seawater or reclaimed water to be re-adsorbed or deposited on the cathode surface, thereby restoring the negative charge density of the negative charge modification layer. A pre-intervention module is used to intervene before the electrolysis hydrogen production reaction begins. Filtering seawater or reclaimed water to remove particulate impurities; In the transport path of seawater or reclaimed water before it enters the electrolysis zone, infrasound of a preset frequency is applied for pre-intervention to disrupt the ordered arrangement of ions in the seawater or reclaimed water and reduce the crystallization activity of ions. The temperature control module, used in the electrolytic hydrogen production reaction, also includes: Real-time monitoring of the input current density of the electrolytic hydrogen production reaction, and acquisition of the fluctuation parameters of the input current density; When the input current density increases and the fluctuation parameter exceeds the second preset threshold, the frequency of the infrasound is increased, and the temperature of the seawater or reclaimed water is adjusted simultaneously to control the temperature fluctuation range of the electrolyte within ±2 degrees Celsius. The precipitation separation module is used after the electrolytic hydrogen production reaction. Physical separation treatment is carried out on seawater or reclaimed water containing sediment; The heat generated by the electrolytic hydrogen production reaction or the introduction of external industrial waste heat is used to evaporate and concentrate the separated seawater or reclaimed water to co-produce fresh water and high-concentration brine.

[0079] This technical solution provides a physical device capable of implementing the aforementioned synergistic anti-fouling control method, clearly defining the various functional units required by the system and their roles, thus providing a clear hardware architecture and implementation foundation for the engineering and industrial application of this technology. The above descriptions are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for controlling the electrolytic hydrogen production process based on infrasound-assisted anti-scaling, characterized in that, The method includes: Hydrogen production by electrolysis of seawater or reclaimed water is carried out in the electrolysis zone using a cathode with a negatively charged surface modification layer. In the electrolytic hydrogen production reaction, infrasound of a preset frequency is applied to the electrolysis zone and its circulation pipeline system to disrupt the fluid boundary layer and peel off the attached substances. The seawater or reclaimed water entering the electrolysis zone is thermally regulated to bring its temperature to a preset electrolysis temperature range. In the electrolytic hydrogen production reaction, an alternating current signal is periodically applied to the cathode, and the functional state of the negative charge modification layer is determined based on the measured electrochemical impedance characteristics of the cathode surface to determine whether the preset repair conditions are met. When the functional state is determined to meet the preset repair conditions, an electrochemical pulse is applied to the cathode to guide the iodine-containing components in the seawater or reclaimed water to be re-adsorbed or deposited on the cathode surface, thereby restoring the negative charge density of the negative charge modification layer.

2. The method for controlling the electrolytic hydrogen production process based on infrasound synergistic anti-fouling as described in claim 1, characterized in that, Before the start of the electrolytic hydrogen production reaction, the following is also included: The seawater or reclaimed water is filtered to remove particulate impurities; In the transport path of the seawater or reclaimed water before it enters the electrolysis zone, infrasound of the preset frequency is applied for pre-intervention to disrupt the ordered arrangement of ions in the seawater or reclaimed water and reduce the crystallization activity of the ions.

3. The method for controlling the electrolytic hydrogen production process based on infrasound synergistic anti-fouling as described in claim 1, characterized in that, The step of using a cathode with a negatively charged surface layer to perform an electrolytic hydrogen production reaction of seawater or reclaimed water in the electrolysis zone includes: Iodine ions are introduced into the cathode surface to construct an iodine-modified layer, which serves as the negative charge modification layer.

4. The method for controlling the electrolytic hydrogen production process based on infrasound synergistic anti-fouling as described in claim 1, characterized in that, The step of applying infrasound of a preset frequency to the electrolysis region and its circulation pipeline system includes: The preset frequency of infrasound is applied by an infrasound generating array with a transmission frequency of 5-20Hz and adjustable sound pressure level, which is set in the electrolysis area and its circulation pipeline system. The preset frequency of the infrasound is 12Hz.

5. The method for controlling the electrolytic hydrogen production process based on infrasound synergistic anti-fouling as described in claim 1, characterized in that, The step of thermally regulating the seawater or reclaimed water entering the electrolysis zone to bring its temperature to a preset electrolysis temperature range includes: External industrial waste heat is introduced as a heat source, and the industrial waste heat is exchanged with the seawater or reclaimed water to bring the temperature of the seawater or reclaimed water to the preset electrolysis temperature range; the preset electrolysis temperature range is 60 degrees Celsius to 80 degrees Celsius.

6. The method for controlling the electrolytic hydrogen production process based on infrasound synergistic anti-fouling as described in claim 1, characterized in that, The step of determining whether the functional state of the negative charge modification layer meets the preset repair conditions based on the measured electrochemical impedance characteristics of the cathode surface includes: When the electrochemical impedance characteristic exceeds a first preset threshold and the reaction time of the electrolytic hydrogen production reaction reaches a preset maintenance time interval, the functional state is determined to meet the preset repair conditions.

7. The method for controlling the electrolytic hydrogen production process based on infrasound synergistic anti-fouling as described in claim 1, characterized in that, The step of applying an electrochemical pulse to the cathode includes: The frequency of the infrasound is switched from the preset frequency to a preset repair guidance frequency, which is used to form a sound pressure standing wave field on the cathode surface. The electrochemical pulse is applied in the infrasonic environment at the preset repair guidance frequency and sustained for a preset duration. The acoustic radiation force generated by the acoustic pressure standing wave field and the electric field force generated by the electrochemical pulse work together to guide the iodine-containing components in the seawater or reclaimed water to be directionally enriched and deposited on the cathode surface.

8. The method for controlling the electrolytic hydrogen production process based on infrasound synergistic anti-fouling as described in claim 1, characterized in that, The electrolytic hydrogen production reaction also includes: The input current density of the electrolytic hydrogen production reaction is monitored in real time, and the fluctuation parameters of the input current density are obtained. When the input current density increases and the fluctuation parameter exceeds the second preset threshold, the frequency of the infrasound is increased, and the temperature of the seawater or reclaimed water is adjusted simultaneously to control the temperature fluctuation range of the electrolyte within ±2 degrees Celsius.

9. A method for controlling the electrolytic hydrogen production process based on infrasound synergistic anti-fouling as described in claim 1, characterized in that, Following the electrolytic hydrogen production reaction, the process further includes: The seawater or reclaimed water containing sediment is physically separated. The heat generated by the electrolytic hydrogen production reaction or the introduction of external industrial waste heat is used to evaporate and concentrate the separated seawater or reclaimed water to co-produce fresh water and high-concentration brine.

10. A control system for an electrolytic hydrogen production process based on infrasound-assisted anti-scaling, used to execute the electrolytic hydrogen production process control method based on infrasound-assisted anti-scaling as described in any one of claims 1 to 9, characterized in that, The system includes: The cathode reaction module is used to carry out the electrolysis of seawater or reclaimed water to produce hydrogen in the electrolysis zone using a cathode with a negatively charged surface modification layer. A mechanical vibration module is used to apply infrasound of a preset frequency to the electrolysis zone and its circulation pipeline system during the electrolysis hydrogen production reaction, so as to disrupt the fluid boundary layer and peel off the attached substances. The thermal energy control module is used to control the thermal energy of the seawater or reclaimed water entering the electrolysis zone so that its temperature reaches the preset electrolysis temperature range. The monitoring module is used to periodically apply an alternating current signal to the cathode during the electrolytic hydrogen production reaction, and determine whether the functional state of the negative charge modification layer meets the preset repair conditions based on the measured electrochemical impedance characteristics of the cathode surface; the repair control module is used to apply an electrochemical pulse to the cathode when it is determined that the functional state meets the preset repair conditions, so as to guide the iodine-containing components in the seawater or reclaimed water to be re-adsorbed or deposited on the cathode surface, thereby restoring the negative charge density of the negative charge modification layer.

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