Propeller blade structure for preventing discharge of marine attached organisms and antifouling method

Abstract

This invention discloses a propeller blade structure and antifouling method for preventing marine biofouling through electrostatic discharge, belonging to the field of marine propeller antifouling technology. The propeller blade body is integrally molded from carbon fiber composite material, with a carbon fiber content of 60%-70% and a conductivity ≥30% IACS, directly serving as the anode working surface of the electrostatic discharge antifouling system, achieving integrated load-bearing, conductivity, and antifouling. A cathode electrode assembly is fixed to the non-working surface of the blade, connected to the blade body via conductive silver paste. An insulating encapsulation layer covers the blade root, non-working surface, and electrode assembly, exposing only the working surface. A low-voltage pulsed DC power supply forms a closed circuit with the blade body as the anode and the cathode electrode as the cathode, employing intermittent pulsed discharge. This utilizes a dual-effect mechanism of micro-electrolysis to generate active substances and a synergistic micro-electric field to prevent marine biofouling. This invention solves the problems of corrosion, heavy metal pollution, and easy peeling of coatings in electrostatic antifouling of metal propellers, achieving green antifouling under all operating conditions.

Description

Technical Field

[0001] This invention belongs to the field of anti-biofouling technology for ship propellers, and specifically relates to a propeller blade structure and antifouling method for preventing marine biofouling by discharging electricity. Background Technology

[0002] The performance of marine propellers directly affects a ship's navigation efficiency, energy consumption, and navigation safety. Seawater is not only highly corrosive but also suitable for the growth of various marine organisms. Ship propellers, constantly immersed in seawater, are easily attached to by marine organisms such as barnacles, bryozoans, microalgae, and shellfish. This attachment typically occurs in four stages. Initially, organic molecules such as proteins and polysaccharides adsorb onto the surface, forming a regulatory film and triggering the next stage. Subsequently, bacteria, microalgae, and exfoliated polysaccharides (EPS) formed a surface biofilm. Then, large spores, such as algal spores and barnacle larvae, attach to the surface. Finally, the spores and larvae develop into mature organisms. These organisms not only disrupt the propeller's surface aerodynamic profile but also reduce its propulsive efficiency and increase drag. The attached organisms produce corrosive substances through metabolism, accelerating propeller corrosion, shortening its lifespan, and hindering noise control, thus affecting the ship's navigation stability. Although the surface area of ​​the propeller is relatively small compared to the overall surface area of ​​the ship, energy losses due to propeller corrosion and fouling account for almost one-third of the total energy loss. Currently, ship propellers are mainly made of metal, and their antifouling methods generally adopt discharge antifouling technologies such as electrolytic antifouling and impressed current antifouling. However, these technologies have inherent material defects and process drawbacks in practical applications.

[0003] CN103088345A discloses a pulsed current method for propeller antifouling, which utilizes the ship's existing impressed current cathodic protection system (ICCP) to electrolyze and generate cuprous ions for antifouling during berthing, using the propeller as the anode for reverse discharge. However, in this method, the copper alloy propeller, as the anode, will undergo continuous anodic dissolution, leading to a decrease in the structural strength of the propeller blades and a significant shortening of its service life; at the same time, the released copper ions and other heavy metals cause marine ecological pollution; during the electrolysis process, calcium and magnesium ions in seawater will also form hard fouling such as calcium carbonate and magnesium hydroxide on the surface of the propeller blades, blocking current conduction and causing a rapid decline in antifouling efficiency.

[0004] EP468739A1 discloses an antifouling method that achieves antifouling by lining the surface of a ship structure with a conductive rubber sheet and applying a microcurrent. US6514401B2 and CN110294083A use conductive coatings such as carbon fiber and graphite applied to the hull surface as an anode, electrolyzing seawater to generate hypochlorite ions for antifouling. However, the adhesion between the conductive coating and the substrate is limited, and it is easily detached and damaged under the high-speed rotation of the propeller and the scouring of water. Once the coating is damaged, localized current concentration can lead to substrate corrosion, and repair is difficult. Furthermore, the coating scheme requires an additional insulating layer, increasing the complexity and cost of construction.

[0005] Carbon fiber reinforced polymer (CFRP) has begun to be used in the propeller field due to its advantages such as light weight, high strength and corrosion resistance. However, the existing technology only focuses on optimizing the structural mechanics and aerodynamic performance, and does not involve related solutions for achieving integrated discharge and anti-fouling by utilizing the conductivity of carbon fiber itself. Summary of the Invention

[0006] To address the technical shortcomings of existing electrolytic antifouling methods for metal propellers, such as easy corrosion, environmental pollution, high energy consumption, limited antifouling scenarios, and cumbersome maintenance, as well as the lack of integrated antifouling design and methods for existing composite material propellers, this invention provides a propeller blade structure and antifouling method that can prevent marine biofouling through discharge. This invention integrates the carbon fiber composite blade body with the discharge antifouling function, using the CFRP blade itself as the anode working surface. Utilizing the excellent conductivity and structural strength of carbon fiber, a conductive path is directly formed on the blade surface, eliminating the need for additional conductive coatings or anode structures. Combined with an integrated cathode assembly on the non-working surface and a fully enclosed insulating package, it achieves integrated load-bearing, conductivity, and antifouling. Employing low-voltage intermittent pulse power supply, it utilizes a dual-effect mechanism of micro-electrolysis generating active substances and micro-electric field physical killing, effectively preventing biofouling while avoiding excessive electrolysis and corrosion of the blade body.

[0007] The technical means employed in this invention are as follows: A propeller blade structure for preventing marine attachment by discharging electricity, comprising: The blade body is integrally formed from carbon fiber composite material, and the working surface of the blade body serves as the anode working surface of the discharge anti-fouling system. An electrode assembly, fixed to the non-working surface of the blade body, includes a cathode electrode and a conductive connector; An insulating encapsulation layer covers the electrode assembly, the root of the blade body, and the non-working surface, while the working surface of the blade body is exposed. The blade body and the electrode assembly are connected by a power source to form a closed circuit. The blade body is used as the anode and the cathode of the electrode assembly is used as the cathode to perform micro-electrolysis on seawater. The active substances generated work together with the micro-electric field to prevent marine organisms from attaching.

[0008] Furthermore, the carbon fiber composite material contains 60% to 70% carbon fiber by mass, employs a ±45° layup process, and has an electrical conductivity ≥30% IACS after molding.

[0009] Furthermore, the cathode electrode is a passivated phosphorus deoxidized copper electrode, and the conductive connector is a two-component epoxy conductive silver paste with a conductivity ≥100S / m and an adhesion strength ≥5MPa.

[0010] Furthermore, the root of the blade body is provided with a mounting hole for mounting to the propeller shaft, and the inner wall of the mounting hole is covered by the insulating encapsulation layer with an insulation resistance ≥10. 10 Ω.

[0011] Furthermore, it also includes a low-voltage pulse power supply interface, which is fixed to the surface of the insulating encapsulation layer and electrically connected to the electrode assembly through a waterproof wire. The interface is sealed with silicone sealant.

[0012] Furthermore, the output parameters of the matching low-voltage pulsed DC power supply are: voltage 0.5~2V, current density 0.1~1mA / cm². 2 The discharge mode is intermittent pulse, which includes a discharge segment and a power-off segment. A micro-current protection pulse is inserted in the power-off segment.

[0013] Furthermore, the discharge time of the intermittent pulse is 30 minutes, and the power-off time is 10 minutes; the voltage of the micro-current protection pulse is 0.5V, and the current density is 0.05mA / cm². 2 Each set lasts 10 seconds, with a 20-second interval, for a total of 3 sets.

[0014] Furthermore, the blade structure also includes a potential monitoring module and a parameter control module, which are used to collect real-time data on the bio-attachment status of the blade surface, seawater temperature and salinity parameters, and dynamically adjust the discharge voltage, current density and pulse interval ratio.

[0015] On the other hand, the present invention also discloses an antifouling method based on the above-mentioned blade structure, comprising the following steps: S1: The carbon fiber composite blade body is installed on the propeller shaft, with the working surface of the blade body exposed facing the seawater, and the non-working surface and root covered by an insulating encapsulation layer. S2: Connect the positive terminal of the low-voltage pulsed DC power supply to the blade body and the negative terminal to the cathode of the electrode assembly. S3: Start the power supply, using the blade body as the anode and the cathode electrode as the cathode, and apply an intermittent pulse current with low voltage and low current density to the seawater; S4: The anodic reaction generates hydroxyl radicals and hypochlorite ions, which damage the cell membranes and genetic material of marine organisms. At the same time, the micro-electric field physically kills the organisms, thus achieving antifouling. S5: During the power outage interval, apply a micro-current protection pulse to maintain the activity of the anode surface and prevent corrosion.

[0016] Furthermore, in step S3, the voltage output by the power supply is 0.5~2V, and the current density is 0.1~1mA / cm². 2 After discharging for 30 minutes, the power was cut off for 10 minutes. During the power-off period, a 0.5V, 0.05mA / cm pulse was applied every 10 seconds for 20 seconds. 2 Protection pulse.

[0017] Compared with the prior art, the present invention has the following advantages: 1. This invention directly uses the carbon fiber composite blade body as the anode working surface. Carbon fiber itself has excellent conductivity and electrochemical stability. During micro-electrolysis, carbon fiber does not undergo anodic dissolution and there is no release of metal ions, fundamentally avoiding a decrease in propeller structural strength and heavy metal contamination. Simultaneously, the carbon fiber surface is not prone to the formation of hard calcium and magnesium fouling, ensuring long-term stable conductivity and anti-fouling efficiency.

[0018] 2. This invention employs a polytetrafluoroethylene (PTFE) spraying process to provide overall insulation and encapsulation for the electrode assembly, blade root, and non-working surfaces, with a thickness of 0.5-1 mm and an insulation resistance ≥ 10 Ω·cm. 10 Ω. Compared with existing conductive rubber or conductive coating solutions, the sprayed insulating layer has a strong bond with the carbon fiber matrix, eliminating the risk of detachment. Simultaneously, the addition of a PTFE sealing strip forms a double-layer seal, preventing seawater from penetrating the electrode connection even under high-speed water flow and long-term immersion, thus eliminating current leakage, electrochemical corrosion, and potential interference with the ship's existing ICCP system. In this invention, the insulating encapsulation layer completely covers the non-working surface; even if localized damage occurs, the corrosion-resistant nature of the carbon fiber itself prevents severe corrosion.

[0019] 3. This invention uses a voltage of 0.5~2V and a current density of 0.1~1mA / cm². 2 Its ultra-low parameters are far below the voltage required for antifouling in metal electrolysis. Intermittent pulse power supply reduces total energy consumption by approximately 75%. During power outages, microcurrent protection pulses are inserted to maintain the electrochemical activity of the anode surface and prevent passivation, while also avoiding excessive oxidation of the carbon fiber surface caused by continuous discharge.

[0020] 4. In addition to generating trace amounts of hypochlorite, this invention also utilizes the physical killing effect of the micro-electric field on organisms: the cell membrane undergoes electroporation in the electric field, leading to leakage of cell contents and cell death. This dual-effect mechanism achieves excellent antifouling effects even at relatively low concentrations of active substances, and the hypochlorite rapidly decomposes in seawater without long-term residual toxicity. During the operation of this device, all indicators of the surrounding seawater meet the national Class I seawater quality standards.

[0021] 5. This invention can be used normally in both sailing and moored states. During sailing, the propeller rotates at high speed, and the working surface of the propeller blades comes into intense contact with seawater. The active substances generated by micro-electrolysis quickly cover the surface, and the micro-electric field also forms a dynamic protective field as the propeller blades rotate. When moored, the intermittent pulse continues to work. It truly achieves all-condition, all-weather antifouling.

[0022] In summary, this invention makes a breakthrough in the technical approach by using the carbon fiber composite blade itself as the anode, achieving a three-in-one integration of load-bearing structure, conductive path and antifouling function. It completely solves the industry pain points of corrosion, pollution and poor coating antifouling durability of metal propeller electrolytic antifouling. It has outstanding advantages such as simple structure, safety and reliability, green environmental protection and low energy consumption, and is suitable for antifouling of propellers of various ships, submarines and marine platforms. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the present invention applied to the anti-fouling discharge of carbon fiber composite propellers.

[0025] Figure 2 This is an exploded view of the blades along the thickness direction, showing the stacking relationship.

[0026] Figure 3 This is a magnified view of a portion of the non-working surface of the blade.

[0027] Figure 4 This is a schematic diagram illustrating the principle of propeller discharge.

[0028] Figure 5 This is a schematic diagram showing the generation of hypochlorite ions at the anode after the propeller discharges. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0033] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0034] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0035] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0036] like Figure 1 As shown, the blade body is integrally molded from carbon fiber composite material, including a working surface and a non-working surface. The working surface is used to generate propulsion force and also serves as the anode working surface for discharge and anti-fouling. The non-working surface is used to fix the electrode assembly and does not participate in propulsion. The root of the blade body is provided with a mounting hole for connection with the propeller shaft, and the inner wall of the mounting hole is insulated.

[0037] The blade body is composite molded from T700 type carbon fiber filaments and epoxy resin, with a carbon fiber filament content of 60%~70%. It employs a ±45° layup process, resulting in a conductivity ≥30% IACS after molding. This directly serves as the anode working surface of the discharge antifouling system, eliminating the need for additional conductive coatings or anode structures, thus integrating the propeller's load-bearing structure, conductive anode, and antifouling function into one integrated unit. The non-working surface integrated cathode assembly includes a cathode electrode and conductive connectors. The cathode electrode is a passivated C5191 type phosphorus deoxidized copper electrode, fixed to the non-working surface of the blade body near the root, not protruding from the blade surface, and thus not affecting the propeller's hydrodynamic performance. The conductive connector is a two-component epoxy conductive silver paste, filled between the copper electrode and the blade body, achieving a firm connection and conductive path between the copper electrode and the blade body. The conductive paste has a conductivity ≥100S / m and a bonding strength ≥5MPa. The fully enclosed insulating protective structure uses polytetrafluoroethylene (PTFE) material. An insulating encapsulation layer is formed on the copper electrodes, conductive connectors, blade root, non-working surfaces, and inner walls of mounting holes through a spray coating process. The coating thickness is controlled to be 0.5~1mm, and the insulation resistance after curing is ≥10 Ω·cm. 10 Ω, with only the working surface of the propeller blade exposed. PTFE sealing strips are added at the connections between the insulating encapsulation layer and each component, forming a double-layer sealing structure to completely prevent seawater infiltration and eliminate current leakage, crevice corrosion, and potential interference with the ship's ICCP system. A waterproof, sealed low-voltage pulse power supply interface is fixed to the surface of the insulating encapsulation layer and electrically connected to the copper electrode via a waterproof wire. The interface is sealed with silicone sealant. The output parameters of the matching low-voltage pulse DC power supply are: voltage 0.5~2V, current density 0.1~1mA / cm². 2 The basic discharge method is intermittent pulse. In this embodiment, the discharge lasts 30 minutes, followed by a 10-minute power-off period. During the power-off interval, three sets of micro-current protection pulses can be inserted. In this embodiment, each set lasts 10 seconds, with a 20-second interval, a voltage of 0.5V, and a current density of 0.05mA / cm². 2 Using the blade body as the anode and the copper electrode as the cathode to form a closed circuit, a dual-effect synergistic mechanism of generating active substances through micro-electrolysis and non-contact physical killing through micro-electric field is achieved to prevent marine attached organisms under all working conditions.

[0038] Optionally, a potential monitoring module and a parameter control module are provided to collect real-time data on the bio-attachment status of the blade surface, seawater temperature, and salinity parameters, and dynamically adjust the discharge voltage, current density, and pulse interval ratio to achieve the lowest energy consumption while ensuring the antifouling effect, and at the same time avoid damage to the carbon fiber blade body due to excessively high potential.

[0039] The anti-fouling method includes the following steps: pre-treating the carbon fiber composite propeller, degreasing and cleaning the working surface and root of the propeller blades, cleaning with anhydrous ethanol for 15-20 minutes to thoroughly remove surface oil, dust and residual impurities; after cleaning, rinsing with deionized water until no residual ethanol remains on the surface, and then drying in an environment of 60-80℃, while ensuring the continuity of the conductive path of the propeller body.

[0040] The copper electrode is fixed to the non-working surface at the root of the carbon fiber propeller with conductive silver paste to ensure a smooth conductive path. Then, polytetrafluoroethylene (PTFE) insulating material is used to completely insulate and encapsulate the copper electrode, propeller journal, and non-working surface, leaving only the working surface of the propeller blade exposed.

[0041] Connect the low-voltage DC power supply to the copper electrodes, and adjust the output parameters to stabilize the voltage between 0.5 and 2V, and the current range between 0.1 and 1 mA / cm². 2 Intermittent pulsed DC discharge is employed, specifically a 30-minute discharge followed by a 10-minute power-off. This discharge method ensures the antifouling effect of the micro-electric field and electrochemical oxidation while avoiding excessive electrolysis and corrosion of the carbon fiber surface caused by continuous discharge, thus protecting the structural integrity of the propeller body while maintaining the antifouling effect. During this process, the carbon fiber propeller body acts as a conductive electrode, forming a uniform micro-electric field in the working surface of the blade and the surrounding seawater. The carbon fiber propeller discharge antifouling is based on the chemical principle of seawater micro-electrolysis, combined with the effect of the micro-electric field to achieve antifouling. This includes the dissociation of the basic electrolyte and electrode redox reactions, the specific equations of which are as follows: H2O H + +OH - NaCl Na + +Cl - Anode reaction: H2O-e - →OH+H + 2Cl - -2e - +H₂O→HClO+H₂ + +Cl2HClO H + +ClO - Cathode reaction: 2H2O+2e - →H₂↑+2OH⁻ - Before the carbon fiber propeller discharges, seawater, acting as the conductive medium, undergoes basic dissociation, providing the ionic basis for subsequent electrolysis reactions. The carbon fiber propeller body, serving as the conductive anode, is the core area for generating antifouling substances. At the anode, water oxidation produces reactive oxygen species, and chloride ion oxidation produces hypochlorite ions. The hydroxyl radicals generated by the oxidation reaction are highly oxidizing, rapidly disrupting the cell membrane structure of marine organisms. Simultaneously, the generated hypochlorous acid and hypochlorite ions are highly effective bactericides, capable of penetrating the cell walls of attached organisms, destroying their genetic material, and ultimately eliminating them. The generated chlorine gas evaporates quickly, leaving no residual toxicity. An external copper electrode, acting as the cathode, primarily undergoes a reduction reaction, providing electronic balance for anodic electrolysis. Its reaction produces only trace amounts of hydrogen gas, preventing localized changes in seawater pH that could alter the marine environment. A potential monitoring and control module is constructed. Using a linear polarization method, scanning from the open-circuit potential, the appropriate range of discharge parameters, including the anode potential range and current density, is determined to prevent excessively high potentials from corroding the carbon fiber propeller.

[0042] Optionally, a potential monitoring and control module can be built, and a suitable discharge parameter range can be determined using the linear polarization method to avoid excessively high potentials corroding the carbon fiber propeller. Real-time data on the biofouling status of the propeller surface is collected, and the discharge parameters are dynamically adjusted according to changes in the marine environment to ensure efficient decontamination with minimal energy loss.

[0043] Example like Figure 1 As shown, this embodiment provides a propeller blade structure for preventing marine organisms from attaching through discharge. The specific implementation process is as follows. All parameters and operations comply with the aforementioned technical solution, ensuring repeatability and feasibility, while verifying the antifouling effect and structural stability of the present invention.

[0044] The following materials were selected: T700 carbon fiber filaments, E51 epoxy resin, sheet copper electrodes (0.3mm thickness, purity ≥99.9%), conductive adhesive (model DJ-701, conductivity 120S / m, bonding strength 6MPa), PTFE coating material (purity ≥99.5%), silicone sealant (model 704, waterproof rating IP68), and a waterproof, sealed low-voltage pulse power supply interface (model DB-15, protection rating IP68). The T700 carbon fiber filaments and E51 epoxy resin were mixed at a mass ratio of 65:35, with an appropriate amount of curing agent added and stirred thoroughly to ensure uniform dispersion of the carbon fiber filaments in the epoxy resin without agglomeration. An alternating ±45° layup process was used within the propeller mold, with a total layup thickness controlled at 6mm. Each layer was compacted after laying to ensure a dense, air-free, and void-free layup. After layup was completed, the upper mold was covered. The mold containing the layup material is placed into a compression molding machine. The molding temperature is set to 135℃ and the molding pressure to 6MPa. The molding is maintained at these parameters for 2 hours under constant temperature and pressure. After that, it is allowed to cool naturally to 25℃. The blade blank is then demolded and removed. The working surface of the blade blank is polished with a grinder to ensure that the surface is smooth, burr-free, and scratch-free, so as to avoid affecting the hydrodynamic and electrical performance. The conductivity of the blade body is tested with a conductivity meter to ensure that it is ≥30%IACS. A mounting hole (50mm in diameter) is machined at the root of the blade body. The inner wall of the mounting hole is insulated with a polytetrafluoroethylene coating with a coating thickness of 0.3mm.

[0045] Apply 0.3mm thick 704 silicone sealant evenly to the copper electrode, conductive adhesive connection, blade root, and non-working surface edges, ensuring complete filling of gaps and preventing seawater infiltration. Then, evenly spray PTFE material onto the copper electrode, conductive connector, blade root, and non-working surfaces, controlling the spray thickness to 0.8mm. Maintain a spraying distance of 30cm during spraying to ensure a uniform, undamaged, and bubble-free coating. Next, place the sprayed blade into a drying device, setting the curing temperature to 90℃ and the curing time to 45 minutes to fully cure the PTFE insulating encapsulation layer. After curing, check to confirm that only the blade working surface is exposed, without any insulating coating. Then, fix the interface by attaching the DB-15 waterproof, sealed low-voltage pulse power supply interface to the insulating encapsulation layer surface, close to the blade root, without affecting blade rotation. Securely fasten with bolts, and seal the fixing point with silicone sealant. Then, electrical connections are made. Waterproof wires are used to connect the power supply interface to the copper electrode. The connection between the wire and the electrode and interface is fixed by crimping. Silicone sealant is then applied to seal the connection to ensure waterproof performance. After the connection is completed, the continuity of the power supply circuit is tested to ensure that there are no open circuits or leakage. The fabrication of the entire blade structure is then completed.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A propeller blade structure for preventing marine organism attachment through electrical discharge, characterized in that, include: The blade body is integrally formed from carbon fiber composite material, and the working surface of the blade body serves as the anode working surface of the discharge anti-fouling system. An electrode assembly, fixed to the non-working surface of the blade body, includes a cathode electrode and a conductive connector; An insulating encapsulation layer covers the electrode assembly, the root of the blade body, and the non-working surface, while the working surface of the blade body is exposed. The blade body and the electrode assembly are connected by a power source to form a closed circuit. The blade body is used as the anode and the cathode of the electrode assembly is used as the cathode to perform micro-electrolysis on seawater. The active substances generated work together with the micro-electric field to prevent marine organisms from attaching.

2. The blade structure according to claim 1, characterized in that, The carbon fiber composite material contains 60% to 70% carbon fiber by mass, and adopts a ±45° layup process. The conductivity after molding is ≥30% IACS.

3. The blade structure according to claim 1, characterized in that, The cathode electrode is a passivated phosphorus deoxidized copper electrode, and the conductive connector is a two-component epoxy conductive silver paste with a conductivity ≥100S / m and an adhesion strength ≥5MPa.

4. The blade structure according to claim 1, characterized in that, The root of the blade body is provided with a mounting hole for mounting to the propeller shaft. The inner wall of the mounting hole is covered by the insulating encapsulation layer with an insulation resistance ≥10. 10 Ω.

5. The blade structure according to claim 1, characterized in that, It also includes a low-voltage pulse power supply interface, which is fixed to the surface of the insulating encapsulation layer and electrically connected to the electrode assembly through a waterproof wire. The interface is sealed with silicone sealant.

6. The blade structure according to claim 5, characterized in that, The output parameters of the matching low-voltage pulsed DC power supply are: voltage 0.5~2V, current density 0.1~1mA / cm². 2 The discharge mode is intermittent pulse, which includes a discharge segment and a power-off segment. A micro-current protection pulse is inserted in the power-off segment.

7. The blade structure according to claim 6, characterized in that, The intermittent pulse discharge time is 30 minutes, and the power-off time is 10 minutes; the micro-current protection pulse voltage is 0.5V, and the current density is 0.05mA / cm². 2 Each set lasts 10 seconds, with a 20-second interval, for a total of 3 sets.

8. The blade structure according to claim 1, characterized in that, The blade structure also includes a potential monitoring module and a parameter control module, which are used to collect real-time data on the bio-attachment status of the blade surface, seawater temperature and salinity parameters, and dynamically adjust the discharge voltage, current density and pulse interval ratio.

9. A method for preventing fouling based on the blade structure according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1: The carbon fiber composite blade body is installed on the propeller shaft, with the working surface of the blade body exposed facing the seawater, and the non-working surface and root covered by an insulating encapsulation layer. S2: Connect the positive terminal of the low-voltage pulsed DC power supply to the blade body and the negative terminal to the cathode of the electrode assembly. S3: Start the power supply, using the blade body as the anode and the cathode electrode as the cathode, and apply an intermittent pulse current with low voltage and low current density to the seawater; S4: The anodic reaction generates hydroxyl radicals and hypochlorite ions, which damage the cell membranes and genetic material of marine organisms. At the same time, the micro-electric field physically kills the organisms, thus achieving antifouling. S5: During the power outage interval, apply a micro-current protection pulse to maintain the activity of the anode surface and prevent corrosion.

10. The antifouling method according to claim 9, characterized in that, In step S3, the power supply output voltage is 0.5~2V, and the current density is 0.1~1mA / cm. 2 After discharging for 30 minutes, the power was cut off for 10 minutes. During the power-off period, a 0.5V, 0.05mA / cm pulse was applied every 10 seconds for 20 seconds. 2 Protection pulse.

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