A liftable netting system and method for offshore wind turbine jacket foundations

Abstract

This invention relates to the field of marine engineering technology, and in particular to a liftable netting system and method for offshore wind turbine jacket foundations. The liftable netting system for offshore wind turbine jacket foundations of this invention includes: a netting body, a closed three-dimensional net cage structure arranged within the internal space of the jacket foundation; a lifting rope system, comprising multiple main lifting ropes, the lower ends of which are connected to the netting body via shackles; a winch system, comprising multiple electric winches, each connected to the upper end of a main lifting rope; a guiding mechanism, each layer of the guiding assembly including guide pulleys mounted on horizontal struts at different heights on the jacket foundation; and a control system for controlling the synchronous movement of the multiple winches. The automated lifting of the netting via the top winch system allows for the completion of most netting maintenance operations on the water surface. This significantly improves operator safety and substantially reduces maintenance costs and time.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and in particular to a netting liftable system and method for offshore wind turbine jacket foundations. Background Technology

[0002] With the comprehensive development of marine resources and the promotion of the concept of intensive use of the sea, the "wind-fishery integration" model has gradually become an important direction for the coordinated development of offshore wind power and mariculture. Among them, integrating aquaculture cages into the foundation of fixed offshore wind turbine jackets to achieve structural and spatial sharing has become one of the research hotspots in this field.

[0003] Currently, the common method of fusion is to directly attach the netting to the support structure of the guide frame through binding or fixing, forming a fixed aquaculture cage. However, this method has many problems in actual operation and maintenance: Difficulty in replacing netting: When the netting ages, is damaged, or needs upgrading due to long-term use, it must be disassembled and installed underwater by divers. In the complex sea conditions of the deep sea, diving operations are not only high-risk, long-term, and costly, but also limited by weather windows, easily leading to interruptions in the aquaculture cycle and affecting production continuity. Inconvenient netting cleaning and maintenance: In the marine environment, algae, shellfish, and other organisms easily adhere to the netting, causing blockage of the mesh and affecting water exchange and the aquaculture environment. Fixed netting is difficult to lift to the surface as a whole, making efficient and thorough mechanized cleaning impossible; traditional underwater cleaning methods are inefficient and ineffective. Low efficiency in fish harvesting: During the harvest season, fixed cages cannot concentrate fish by lifting the netting, making it difficult to coordinate with automated equipment such as fish suction pumps for efficient and damage-free fish harvesting. Traditional netting is still the main method, which is labor-intensive and has a low degree of automation.

[0004] Therefore, there is an urgent need for a system solution that can achieve overall automation of netting, significantly reduce reliance on underwater manual labor, and improve operation and maintenance safety and efficiency, so as to promote the sustainable development of deep integration between offshore wind power and marine aquaculture. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problems of difficulty in replacing netting, inconvenience in cleaning and maintaining netting, and low efficiency in fish harvesting in the prior art.

[0006] To address the aforementioned technical problems, this invention provides a netting liftable system for offshore wind turbine jacket foundations, comprising: The mesh body is a closed three-dimensional mesh box structure arranged inside the foundation of the guide frame, with the top of the three-dimensional mesh box structure being open; The lifting rope system includes multiple main lifting ropes, the lower ends of which are connected to the netting body via shackles; The winch system comprises multiple electric winches, which are installed on the fan operating platform at the top of the jacket foundation. Each electric winch is connected to the upper end of a main lifting cable. The guiding mechanism includes a multi-layer guiding assembly, each layer of which includes guide pulleys mounted on horizontal struts at different heights on the jacket foundation to constrain the movement trajectory of the main lifting cable. The control system is electrically connected to the winch system and integrates a programmable logic controller and a human-machine interface for receiving instructions and controlling the synchronous operation of multiple winches.

[0007] Preferably, a horizontal rigid frame is fixedly connected to the bottom of the mesh body; the lower end of the main lifting rope is evenly connected to multiple lifting points of the rigid frame.

[0008] Preferably, the rigid frame is made of high-strength, corrosion-resistant steel pipe, and its interior is encapsulated with closed-cell foam floating material.

[0009] Preferably, the control system controls the speed and torque of each winch through a frequency converter, and realizes synchronous linkage of multiple winches based on encoder feedback, so as to ensure that the netting maintains a horizontal posture during the lifting and lowering process.

[0010] Preferably, the guide pulley in the guiding mechanism is made of engineering plastic; the limiting ring is a metal ring with an inner liner, which is fixed to the horizontal support rod by U-bolts.

[0011] Preferably, the net body is woven from ultra-high molecular weight polyethylene fiber, the mesh size of the net can be adjusted according to the aquaculture species, and the upper part of the net is connected to the inner side of the guide frame base by a detachable fastener.

[0012] The present invention also provides a method for lifting netting for offshore wind turbine jacket foundations, comprising: The control system issues a lifting command, starts all winches to synchronously retrieve the main lifting rope, and vertically lifts the net body from the underwater working position until the bottom of the net is pulled to the predetermined height. Once the bottom of the netting is stable, the old netting is removed from the rigid frame and replaced with a new netting. The netting is then cleaned and maintained using a high-pressure water gun. The fish are efficiently collected by using the concentrated space at the bottom of the net cage after the cage is lifted, in conjunction with a fish suction pump. After the surface operations are completed, the control system controls all winches to release the main lifting rope synchronously, so that the net body is smoothly lowered and returned to its original working position under the auxiliary guidance of gravity and the rigid frame.

[0013] Preferably, the quick connector pre-installed on the rigid frame is used for quick separation and connection between the mesh and the lifting system, and the quick connector includes a male and female pin mechanism.

[0014] Preferably, the control system receives feedback signals from the water level sensor and adjusts the operating speed and synchronization of the winch in real time.

[0015] Preferably, during the lifting process of the mesh, the integrity of the mesh is monitored by a camera installed on the guide frame to identify whether there is any damage or abnormal attachment.

[0016] The technical solution of the present invention has the following advantages compared with the prior art: This invention discloses a net lifting system and method for offshore wind turbine jacket foundations. Through a top winch system, the entire net is automatically lifted, allowing major maintenance operations such as net replacement, inspection, and cleaning to be completed on the water surface. This completely eliminates reliance on high-risk, high-cost underwater operations by divers, greatly improving operator safety and significantly reducing maintenance costs and cycles. The lifting and lowering of the net is automatically and synchronously completed by the control system, with fast operation and short time consumption. This process is far less affected by adverse sea conditions than underwater operations, effectively overcoming the strict limitations of traditional diving operations on weather windows, improving the continuity and planning of aquaculture operations, and resulting in a qualitative leap in overall maintenance efficiency. By lifting the net, fish are naturally concentrated in the narrow space at the bottom of the cage, greatly facilitating cooperation with automated equipment such as fish suction pumps, achieving efficient and damage-free fish harvesting operations. The net can be partially or entirely lifted to the water surface for comprehensive and thorough cleaning using high-pressure water guns or net-washing robots, effectively removing attached substances and ensuring water exchange and a healthy aquaculture environment within the cage. Attached Figure Description

[0017] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a structural diagram of a netting liftable system for offshore wind turbine jacket foundations provided by the present invention; Figure 2 This is a flowchart of a method for lifting netting for offshore wind turbine jacket foundations provided by the present invention. Detailed Implementation

[0018] The core of this invention is to provide a netting lifting system for offshore wind turbine jacket foundations. The system achieves overall automated lifting of the netting through a top winch system, enabling major maintenance operations such as netting replacement, inspection, and cleaning to be completed on the water surface.

[0019] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please refer to Figure 1. Figure 1 The logical relationship diagram of a netting liftable system for offshore wind turbine jacket foundations provided by this invention; the specific operation steps are as follows: The mesh body is a closed three-dimensional mesh box structure arranged inside the foundation of the guide frame, with the top of the three-dimensional mesh box structure being open; In one embodiment, a horizontal rigid frame is fixedly connected to the bottom of the net body; the lower end of the main lifting rope is evenly connected to multiple lifting points of the rigid frame, wherein the rigid frame is made of high-strength corrosion-resistant steel pipe and encapsulates closed-cell foam floating material inside; the net body is woven from ultra-high molecular weight polyethylene fiber; the mesh size of the net can be adjusted according to the aquaculture species; and the upper rope of the net is connected to the inner side of the guide frame foundation by a detachable fastener.

[0021] Specifically, the netting body is constructed by stitching or weaving side netting and bottom netting to form a three-dimensional net cage structure that is closed at the bottom and all four sides and open at the top. Its horizontal projection shape is adapted to the contour of the internal space of the guide frame foundation, including but not limited to square, rectangular, or polygonal shapes. An upper rope is fixed to the upper edge of the side netting, and this upper rope is flexibly connected to a pre-set anchor point on the inside of the guide frame foundation via a series of detachable connectors, such as shackles, mooring rings, or ropes. This open-top design ensures sufficient exchange between the inside of the net cage and the external water, effectively prevents farmed fish from jumping out of the top of the net cage and escaping, and provides a convenient entry point for feeding via a surface feeding boat or automatic feeding system.

[0022] The lifting rope system includes multiple main lifting ropes, the lower ends of which are connected to the netting body via shackles; In one embodiment, the hoisting rope system consists of at least four uniformly and symmetrically arranged main hoisting ropes, preferably made of high-strength, low-elongation ultra-high molecular weight polyethylene cable or galvanized steel wire rope, possessing excellent corrosion resistance and fatigue resistance. The lower end of each main hoisting rope is mechanically connected to a pre-set lifting point on the rigid frame at the bottom of the netting body, or directly to a reinforcing node on the bottom rope of the netting, via a seawater-resistant shackle. At the upper end of the main hoisting rope, standardized end fittings, such as pear-shaped rings or pressed joints, are provided for connecting to the winch system drum. Furthermore, tension monitoring sensors or color-coded segments can be installed on the main hoisting ropes to monitor the stress state during the hoisting process in real time and to visually determine the length of the rope being wound up or down, respectively.

[0023] The winch system comprises multiple electric winches, which are installed on the fan operating platform at the top of the jacket foundation. Each electric winch is connected to the upper end of a main lifting cable. In one embodiment, the winch system comprises multiple independently controlled electric winches, the number and arrangement of which correspond to the number and spatial distribution of the main lifting ropes. These electric winches are securely mounted on a specially designed reinforced base on the wind turbine operating platform atop the jacket foundation using high-strength bolts. This reinforced base is located above the main columns or major load-bearing components of the jacket to ensure effective load transfer. The drum of each electric winch is fixedly connected to the upper end of a main lifting rope via a pressure plate or wedge joint. Each electric winch integrates a brake, overload protection device, and an encoder for feedback on the rope winding and unwinding length and speed. The electric winches are driven by variable frequency motors or hydraulic motors and are uniformly commanded by the control system. This system enables synchronous start-up, synchronous operation, and synchronous stopping of multiple winches, and provides individual winch fine-tuning capabilities to dynamically compensate for uneven rope tension caused by ocean currents and waves, thereby ensuring the stability and horizontal orientation of the entire netting lifting process.

[0024] The guiding mechanism includes a multi-layer guiding assembly, each layer of which includes guide pulleys mounted on horizontal struts at different heights on the jacket foundation to constrain the movement trajectory of the main lifting cable. In one embodiment, the guide pulley in the guide mechanism is made of engineering plastic; the limiting ring is a metal ring with an inner liner, which is fixed to the horizontal support rod by U-bolts.

[0025] Specifically, the guiding mechanism consists of multiple layers of guiding components spaced at intervals along the depth of the jacket foundation. The number and position of these layers correspond to the height of the netting body and the distribution of the horizontal struts of the jacket. Each layer of guiding components includes at least four guide pulleys, which are securely mounted on different horizontal struts at the same height on the jacket foundation using corrosion-resistant U-bolts or dedicated welded supports. The guide pulleys are preferably made of MC nylon or covered with ultra-high molecular weight polyethylene bushings to reduce friction and wear with the main hoisting rope and minimize operating noise. Each pulley has a groove matching the diameter of the main hoisting rope, ensuring that the rope is always confined within the groove, thus precisely restraining its vertical and lateral movement. This mechanism works together to form a continuous, smooth vertical guiding channel from the working water depth of the netting to the top winch system, effectively preventing the main hoisting rope from entangled, colliding with, or excessively laterally swaying with the jacket structure during lifting and lowering, ensuring a clear force transmission path and reliable system operation.

[0026] The control system is electrically connected to the winch system and integrates a programmable logic controller and a human-machine interface for receiving instructions and controlling the synchronous operation of multiple winches.

[0027] In one embodiment, the control system controls the speed and torque of each winch through a frequency converter and achieves synchronous linkage of multiple winches based on encoder feedback, ensuring that the netting maintains a horizontal posture during lifting and lowering.

[0028] Specifically, the control system is the core control unit, which is electrically connected to each electric winch in the winch system and various sensors via an industrial fieldbus or Ethernet. The system hardware integrates a programmable logic controller (PLC), a human-machine interface (HMI), and a motor drive module. The PLC has pre-stored the control logic program for the net lifting, and can process local operation commands from the HMI or remote wireless commands from the host computer. It also receives in real time the rope length and speed signals fed back by the encoder integrated on the winch, as well as the rope tension signals fed back by the tension sensor. Based on these signals, the PLC dynamically adjusts the operating speed and output torque of each winch through a built-in synchronization control algorithm, achieving precise synchronization of multiple winches throughout the start-up, operation, and shutdown processes. The HMI is located on the wind turbine platform or onshore control center, used to display the real-time operating status of each winch, the current position of the net, system alarm information, and provides multiple operating modes such as automatic and manual. In addition, the control system also integrates a safety protection module. When it detects that the tension of the rope exceeds the limit, the lifting height exceeds the range, or the single machine has too large asynchrony deviation, it can immediately execute an emergency stop or corresponding correction procedure to ensure the safe, stable and automated operation of the entire lifting process.

[0029] This embodiment provides a net lifting system for offshore wind turbine jacket foundations. A top winch system automates the lifting of the net, enabling major maintenance operations such as net replacement, inspection, and cleaning to be completed on the water surface. This completely eliminates reliance on high-risk, high-cost underwater operations by divers, significantly improving operator safety and reducing maintenance costs and time. The lifting and lowering of the net is automatically and synchronously completed by the control system, resulting in fast operation and short processing time. This process is far less affected by adverse sea conditions than underwater operations, effectively overcoming the strict weather window limitations of traditional diving operations, improving the continuity and planning of aquaculture maintenance, and achieving a qualitative leap in overall maintenance efficiency. Lifting the net naturally concentrates fish in the narrow space at the bottom of the cage, greatly facilitating coordination with automated equipment such as fish suction pumps, enabling efficient and damage-free fish harvesting. The net can be partially or entirely lifted to the surface for thorough cleaning using high-pressure water guns or net-washing robots, effectively removing deposits and ensuring healthy water exchange and a healthy aquaculture environment within the cage.

[0030] like Figure 2 As shown, Figure 2 The present invention provides a method for lifting the netting used in offshore wind turbine jacket foundations, as detailed below: Step S201: Issue a lifting command through the control system to start all winches to synchronously retrieve the main lifting rope, and vertically lift the net body from the underwater working position until the bottom of the net is pulled to a predetermined height; Step S202: After the bottom of the net is stable, remove the old net from the rigid frame and replace it with a new net. Use a high-pressure water gun to clean and maintain the net. Use the concentrated space at the bottom of the net cage formed after lifting to collect fish efficiently with a fish suction pump. Step S203: After the surface operation is completed, the control system controls all winches to release the main lifting rope synchronously, so that the net body is smoothly lowered and reset to the original working position under the auxiliary guidance of gravity and rigid frame.

[0031] Based on the above embodiments, this embodiment will provide a detailed description of step S201: In one embodiment, a pre-installed quick connector on the rigid frame is used for quick separation and connection between the mesh and the lifting system, the quick connector including a male and female pin mechanism.

[0032] Specifically, the operator selects the automatic lifting mode and sets the target lifting height through the human-machine interface (HMI) of the control system, and then issues a lifting command. Upon receiving this command, the programmable logic controller (PLC) of the control system first executes a self-test program to confirm that the brakes of each winch are open, the initial tension of the rope is normal, and there are no fault alarms. Subsequently, the PLC, based on its built-in synchronous control algorithm, simultaneously sends start signals to the frequency converter drives of all electric winches. Each winch starts smoothly under the frequency converter drive, synchronously retracting the main lifting rope at a preset initial low speed. After the rope tension is eliminated and the netting begins to move, it gradually accelerates to the set normal lifting speed. During the lifting process, the PLC continuously receives and compares the rope length and speed data fed back from the encoders of each winch, as well as the real-time tension data fed back from the tension sensors. It dynamically fine-tunes the speed and torque of each winch through a PID adjustment algorithm to compensate for asynchrony caused by ocean current impact, wave loads, or differences in mechanical transmission, ensuring that the netting body always maintains a horizontal posture and rises steadily as a whole. When the wire rope recovery length fed back by any encoder reaches the calculated value corresponding to the predetermined height, the PLC immediately issues a command to all winches to smoothly decelerate and stop, ultimately causing the bottom of the netting to precisely hover at the predetermined height, completing the lifting operation.

[0033] Based on the above embodiments, this embodiment will provide a detailed description of step S202: In one embodiment, a pre-installed quick connector on the rigid frame is used for quick separation and connection between the mesh and the lifting system, the quick connector including a male and female pin mechanism.

[0034] Specifically, once the bottom of the netting is stabilized near the water surface or at an appropriate height under the control system, operators can safely stand on the surface workboat or jacket platform and efficiently perform one or more of the following core operation and maintenance operations without any diving: Net replacement operation: The operator first uses the quick connectors mounted on the rigid frame to detach the top and side nets of the old net from the connection points at the lower end of the rigid frame and / or the main lifting rope. Then, the new net, pre-folded or wound on the work platform, is unfolded, and its top and side nets are reliably reconnected to the rigid frame and main lifting rope system using the same quick connectors, completing the overall underwater net replacement.

[0035] Net cleaning and maintenance operations: Operators use high-pressure water pump units mounted on work boats or platforms to generate high-pressure water jets. Through handheld or robotic arm-controlled high-pressure water gun nozzles, they scan and rinse each section of the net raised above the water surface. Alternatively, they control a dedicated automatic net washing robot to crawl along the surface of the net, using its rotating brush head and jet of water to thoroughly clean both sides of the net, effectively removing attached algae, shellfish, and other marine organisms.

[0036] Highly efficient centralized fish harvesting: The conical or concentrated space at the bottom of the net cage, created by the lifting of the net, drives and confines the scattered fish to this narrow area. Then, the fish suction pump system is activated, inserting the pump's suction head into the concentrated fish population. Using negative pressure, the fish, along with the water, are sucked up without damage and transported to temporary holding cages on transport ships or processing platforms. This achieves rapid, high-capacity fish harvesting with minimal damage to the fish.

[0037] Based on the above embodiments, this embodiment will provide a detailed description of step S203: In one embodiment, the control system receives feedback signals from a water level sensor and adjusts the winch's operating speed and synchronization in real time. During the netting lifting process, a camera mounted on the guide frame monitors the integrity of the netting to identify any damage or abnormal attachments.

[0038] Specifically, once all surface operations are completed, the operator issues a lowering command through the control system. The programmable logic controller (PLC) of the control system first controls the brakes of all electric winches to open in an orderly manner and instructs the frequency converter driver to enter synchronous lowering mode. Under the coordination of the control system, the winch system begins to release the main hoisting rope synchronously and at a uniform speed. The net body begins to sink under its own weight. Its bottom rigid frame, utilizing its own weight and hydrodynamic shape, plays a role in assisting centering and stabilizing its posture in the vertical channel formed by the guide mechanism, effectively suppressing the rotation and lateral drift of the net during the sinking process.

[0039] During the lowering process, the control system continuously monitors the real-time tension of each main lifting rope and the lowering length fed back by the encoder. It dynamically adjusts the release speed of each winch through a synchronous control algorithm to ensure the netting remains horizontal and descends smoothly. When the lowering length fed back by the encoder approaches the set value corresponding to the netting's original working position, the PLC controls all winches to switch to low-speed operation mode for smooth deceleration. Finally, when the rigid frame at the bottom of the netting accurately touches the preset limit support at the bottom of the guide frame foundation, or when all sensor data confirms that the netting has been completely reset, the winches stop releasing, the brakes engage and lock, completing the entire lowering and reset process. This system ensures that the netting can return to its initial aquaculture position accurately and without damage, preparing it for the next aquaculture cycle.

[0040] This embodiment provides a method for lifting netting for offshore wind turbine jacket foundations. A top winch system automates the lifting of the netting, allowing key maintenance tasks such as netting replacement, inspection, and cleaning to be completed on the water surface. This completely eliminates reliance on high-risk, high-cost underwater operations by divers, significantly improving operator safety and reducing maintenance costs and time. The lifting and lowering of the netting is automatically and synchronously completed by the control system, resulting in fast operation and short processing time. This process is far less affected by adverse sea conditions than underwater operations, effectively overcoming the strict weather window limitations of traditional diving operations, improving the continuity and planning of aquaculture maintenance, and achieving a qualitative leap in overall maintenance efficiency. Lifting the netting allows fish to naturally concentrate in the narrow space at the bottom of the cage, greatly facilitating coordination with automated equipment such as fish suction pumps, enabling efficient and damage-free fish harvesting. The netting can be partially or entirely lifted to the surface for thorough cleaning using high-pressure water guns or net-washing robots, effectively removing deposits and ensuring healthy water exchange and a healthy aquaculture environment within the cage.

[0041] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A netting liftable system for offshore wind turbine jacket foundations, characterized in that, include: The mesh body is a closed three-dimensional mesh box structure arranged inside the foundation of the guide frame, with the top of the three-dimensional mesh box structure being open; The lifting rope system includes multiple main lifting ropes, the lower ends of which are connected to the netting body via shackles; The winch system comprises multiple electric winches, which are installed on the fan operating platform at the top of the jacket foundation. Each electric winch is connected to the upper end of a main lifting cable. The guiding mechanism includes a multi-layer guiding assembly, each layer of which includes guide pulleys mounted on horizontal struts at different heights on the jacket foundation to constrain the movement trajectory of the main lifting cable. The control system is electrically connected to the winch system and integrates a programmable logic controller and a human-machine interface for receiving instructions and controlling the synchronous operation of multiple winches.

2. The netting liftable system for offshore wind turbine jacket foundations according to claim 1, characterized in that, The bottom of the mesh body is fixedly connected to a horizontal rigid frame; the lower end of the main lifting rope is evenly connected to multiple lifting points of the rigid frame.

3. The netting liftable system for offshore wind turbine jacket foundations according to claim 2, characterized in that, The rigid frame is made of high-strength, corrosion-resistant steel pipe, and its interior is encapsulated with closed-cell foam buoyant material.

4. The netting liftable system for offshore wind turbine jacket foundations according to claim 1, characterized in that, The control system controls the speed and torque of each winch through a frequency converter and achieves synchronous linkage of multiple winches based on encoder feedback, ensuring that the netting maintains a horizontal posture during lifting and lowering.

5. The netting liftable system for offshore wind turbine jacket foundations according to claim 1, characterized in that, The guide pulley in the guiding mechanism is made of engineering plastic; the limiting ring is a metal ring with an inner lining, which is fixed to the horizontal support rod by U-bolts.

6. The netting liftable system for offshore wind turbine jacket foundations according to claim 1, characterized in that, The net body is woven from ultra-high molecular weight polyethylene fiber. The mesh size of the net can be adjusted according to the aquaculture species. The upper part of the net is connected to the inner side of the guide frame base by a detachable fastener.

7. A method for lifting netting for offshore wind turbine jacket foundations, characterized in that, include: The control system issues a lifting command, starts all winches to synchronously retrieve the main lifting rope, and vertically lifts the net body from the underwater working position until the bottom of the net is pulled to the predetermined height. Once the bottom of the netting is stable, the old netting is removed from the rigid frame and replaced with a new netting. The netting is then cleaned and maintained using a high-pressure water gun. The fish are efficiently collected by using the concentrated space at the bottom of the net cage after the cage is lifted, in conjunction with a fish suction pump. After the surface operations are completed, the control system controls all winches to release the main lifting rope synchronously, so that the net body is smoothly lowered and returned to its original working position under the auxiliary guidance of gravity and the rigid frame.

8. The method for lifting the netting for offshore wind turbine jacket foundations according to claim 7, characterized in that, The quick connector pre-installed on the rigid frame is used for quick separation and connection between the netting and the lifting system. The quick connector includes a male and female pin mechanism.

9. The method for lifting the netting for offshore wind turbine jacket foundations according to claim 7, characterized in that, The control system receives feedback signals from the water level sensor and adjusts the winch's operating speed and synchronization in real time.

10. The method for lifting the netting for offshore wind turbine jacket foundations according to claim 9, characterized in that, During the lifting process of the mesh, the integrity of the mesh is monitored by a camera installed on the guide frame to identify whether there is any damage or abnormal attachment.

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