A mooring system for offshore wind power monopile foundations

Abstract

This application relates to the field of offshore wind power technology and provides a mooring system for offshore wind turbine monopile foundations, comprising: a monopile foundation body; a hollow rubber fender; and a vertical traction device including a buoy, a traction rope, an upper steering device, and a steering hole. The upper steering device is fixed to the outer wall of the monopile foundation body and located above the hollow rubber fender. The steering hole is opened on the wall of the monopile foundation body, located below the hollow rubber fender, and connects the interior of the monopile foundation body with the external seawater. One end of the traction rope is connected to the hollow rubber fender, turns upward through the upper steering device, and then passes downward through the steering hole into the interior of the monopile foundation body to connect with the buoy. The buoy is located inside the monopile foundation body and floats on the water surface, used to adjust the height of the hollow rubber fender according to water level changes via the traction rope. This invention achieves autonomous adjustment of the fender height according to water level, solving the technical problem that existing mooring systems cannot adapt to changes in water level.

Description

Technical Field

[0001] This application relates to the field of offshore wind power technology, specifically to a mooring system for offshore wind turbine monopile foundations. Background Technology

[0002] Offshore wind power, as an important component of renewable energy, is being developed on an increasingly large scale. Monopile foundations, due to their relatively simple structure, low manufacturing cost, and wide applicability in water depths, have become the mainstream foundation type for offshore wind turbines. During the installation, commissioning, operation, and maintenance phases of monopile foundations, the berthing of the vessel with the foundation is an essential step to facilitate the transfer of personnel and materials to the platform.

[0003] Currently, existing berthing systems for offshore wind turbine monopile foundations generally employ a rigid berthing bollard combined with a rubber fender. However, the sea areas where offshore wind turbine monopile foundations are located typically have large tidal ranges, and the existing berthing bollards and rubber fenders are mostly fixed installations, unable to automatically adjust their height according to water level changes. At low water levels, the fender is too high, making it difficult for the vessel to effectively contact it during berthing; at high water levels, the fender may be submerged or positioned too low. Existing technologies mainly address berthing needs at different tidal ranges by lengthening the berthing bollard, but this method increases material usage and manufacturing costs, and fails to fundamentally solve the matching problem between the fender and the vessel at different water levels. Chinese patent application CN212153297U discloses a novel rubber fender structure with a hollow buffer body and hollow, through-hole-equipped hanging rods. This solution improves buffering capacity by drawing in some seawater, but the fender still needs to be partially submerged in water, and its working position is fixed. It also cannot automatically adjust its height according to changes in water level, making it difficult to adapt to the large tidal range conditions of offshore wind power. Summary of the Invention

[0004] The present invention aims to solve the problem that the mooring system used for offshore wind power monopile foundations in the prior art cannot automatically adjust the fender height according to changes in water level, and provides a mooring system for offshore wind power monopile foundations.

[0005] To achieve the above objectives, this application provides a mooring system for offshore wind power monopile foundations, comprising: a monopile foundation body, wherein the interior of the monopile foundation body is provided with a buoy that floats on the water surface;

[0006] Hollow rubber fenders; Lateral traction device is used to install the hollow rubber fender onto the monopile foundation body; The vertical traction device includes a traction rope, an upper steering device, and a steering hole. The upper steering device is fixed to the outer wall of the monopile foundation body and located above the hollow rubber fender. The steering hole is opened on the wall of the monopile foundation body and located below the hollow rubber fender, and the steering hole connects the interior of the monopile foundation body with the external seawater. One end of the traction rope is connected to the hollow rubber fender, and the other end is turned upward through the upper steering device and then passed downward through the steering hole into the interior of the monopile foundation body to connect with the buoy. The hollow rubber fender adaptively adjusts its height according to changes in water level.

[0007] In one embodiment, the hollow rubber fender has a cavity inside and a vent communicating with the cavity.

[0008] In one embodiment, the number of hollow rubber fenders is 2 to 4, which are evenly arranged along the circumference of the monopile foundation body.

[0009] In one embodiment, the lateral traction device includes two traction components symmetrically arranged on both sides of the hollow rubber fender. Each traction component includes a spring, a connecting rope, and an anchoring point. One end of the connecting rope is connected to the hollow rubber fender through the spring, and the other end of the connecting rope is fixed to the anchoring point, which is located on the monopile foundation body.

[0010] In one embodiment, the vents of the hollow rubber fender are located at the upper and lower ends of the hollow rubber fender.

[0011] In one embodiment, the hollow rubber fender is provided with stiffening ribs inside.

[0012] In one embodiment, the hollow rubber fender has layers of rubber-coated curtain fabric embedded within its rubber material, with adjacent layers of rubber-coated curtain fabric laid at an intersecting angle.

[0013] In one embodiment, the adhesive-coated curtain fabric has 2 to 3 layers.

[0014] Compared with the prior art, this application has the following beneficial effects: This application relates to a mooring system for offshore wind turbine monopile foundations. The vertical traction device, through the coordination of buoys, traction ropes, an upper steering device, and steering holes, enables the hollow rubber fender to automatically adjust its height according to water level changes. The buoys float on the water surface inside the monopile foundation, which is connected to the external seawater through the steering holes. The water level inside the pile changes synchronously with the sea level. When the water level rises, the buoys rise and move the fenders upward via the traction ropes; when the water level falls, the buoys fall, and the fenders move downward under their own weight. The fender height always adapts to the water level, requiring no manual intervention or the extension of the berthing bollard, thus saving material costs and maintenance workload. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the three-dimensional structure of a mooring system for offshore wind turbine monopile foundations is shown. Figure 2 The schematic diagram shows the main view of the mooring system used for offshore wind turbine monopile foundations. Figure 3 The schematic diagram shows a side view of the mooring system used for offshore wind turbine monopile foundations. Figure 4 The schematic diagram shows a top view of the mooring system used for offshore wind turbine monopile foundations. Figure 5 yes Figure 2 Schematic diagram of the cross-sectional structure along the AA direction; Figure 6 yes Figure 4 Schematic diagram of the cross-sectional structure in the middle BB direction; Figure 7 yes Figure 4 A schematic diagram of the cross-sectional structure along the CC direction.

[0017] Reference numerals in the attached drawings: 1: Main body of monopile foundation; 2: Cavity rubber fender; 3: Mooring bollard; 4: Cage; 5: Crane; 6: Outer platform; 7: Inner platform; 8: Turning hole; 9: Vertical traction rope; 10: Upper turning device; 11: Float; 12: Spring; 13: Connecting rope; 14: Anchor point; 15: Vent; 16: Top flange of monopile. Detailed Implementation

[0018] To facilitate understanding of this application, the following description will be more comprehensive and detailed in conjunction with the accompanying drawings and preferred embodiments, but the scope of protection of this application is not limited to the following specific embodiments.

[0019] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of this application.

[0020] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0021] Please see Figures 1-7 One embodiment of a mooring system for offshore wind turbine monopile foundations includes: a monopile foundation body 1, a hollow rubber fender 2, a lateral traction device, and a vertical traction device.

[0022] The monopile foundation body 1 serves as the support structure for the offshore wind turbine generator and is constructed using steel pipe piles driven into the seabed. The interior of the monopile foundation body 1 contains floating pontoons 11.

[0023] Specifically, in one embodiment, the hollow rubber fender 2 has a cavity inside and a vent 15 communicating with the cavity. Specifically, in one embodiment, there are 2 to 4 hollow rubber fenders 2, evenly arranged along the circumference of the monopile foundation body 1. Specifically, in one embodiment, the vent 15 of the hollow rubber fender 2 is located at the upper and lower ends of the hollow rubber fender 2. In a specific embodiment, the hollow rubber fender 2 is a vertically arranged capsule shape, each hollow rubber fender 2 having a length of approximately 3 to 5 m and a diameter of approximately 1.5 to 2.5 m. The vent 15 is a circular hole with a diameter of 100 mm, and the edge of the vent 15 is rounded to reduce airflow friction loss and increase structural strength. The vent 15 is only a connection channel between the cavity and the external air, without one-way valves, water inlets, or other auxiliary structures; it is only used for gas intake and exhaust, resulting in a simple structure that avoids the risk of blockage by marine organisms and offers higher reliability during long-term service.

[0024] Specifically, in one embodiment, the hollow rubber fender 2 has reinforcing ribs inside. Specifically, the rubber material of the hollow rubber fender 2 is layered with rubber-coated fabric, with adjacent layers of rubber-coated fabric laid at an intersecting angle. Specifically, there are 2-3 layers of rubber-coated fabric. Specifically, the rubber material is a mixture of neoprene rubber and styrene-butadiene rubber, formed through a vulcanization process, and has a Shore A hardness of approximately 60-70 degrees. The internal cavity of the hollow rubber fender 2 is capsule-shaped, with the cavity volume accounting for 80%-90% of the total fender volume, and the cavity wall thickness is uniform. The rubber-coated fabric improves the structural strength and puncture resistance of the hollow rubber fender 2.

[0025] The lateral traction device is used to install the hollow rubber fender 2 onto the monopile foundation body 1. Specifically, the lateral traction device includes two traction components, which are symmetrically arranged on both sides of the hollow rubber fender 2. Each traction component includes a spring 12, a connecting rope 13, and an anchoring point 14. One end of the connecting rope 13 is connected to the hollow rubber fender 2 via the spring 12, and the other end of the connecting rope 13 is fixed to the anchoring point 14, which is located on the monopile foundation body 1. The lateral traction device is used to horizontally reset the hollow rubber fender 2 after berthing.

[0026] The vertical traction device includes a traction rope 9, an upper steering device 10, and a steering hole 8. The steering hole 8 is located on the wall of the monopile foundation body 1 and below the hollow rubber fender 2, connecting the interior of the monopile foundation body 1 with the external seawater. Specifically, when the system is operating, the steering hole 8 is below the water surface, and the interior of the monopile foundation body 1 is connected to the external seawater through the steering hole 8, with the water level inside the pile changing synchronously with the sea level. The upper steering device 10 is fixed to the outer wall of the monopile foundation body 1 and located above the hollow rubber fender 2. In one specific embodiment, the upper steering device 10 is a fixed pulley. One end of the traction rope 9 is connected to the hollow rubber fender 2, and the other end is turned upwards by the upper steering device 10 and then downwards through the steering hole 8, entering the interior of the monopile foundation body 1 and connecting with the buoy 11. The hollow rubber fender 2 adaptively adjusts its height according to changes in water level. Specifically, when the water level rises, the buoy 11 rises with the water level and pulls the traction rope 9 upward. After the traction rope 9 is turned by the upper turning device 10 through the turning hole 8, it pulls the hollow rubber fender 2 upward. When the water level drops, the buoy 11 drops with the water level, and the hollow rubber fender 2 moves downward under its own weight until it reaches equilibrium with the pulling force of the buoy 11. Specifically, in one embodiment, the hollow rubber fender 2 always operates above the water surface, avoiding seawater immersion and corrosion, extending the service life of the fender, and eliminating the risk of marine organisms clogging the air vents.

[0027] Specifically, an annular outer platform 6 is fixed to the top of the monopile foundation body 1, extending to the periphery of the monopile foundation body 1 to support the crane 5 and provide access for personnel. An inner platform 7 is provided inside the monopile foundation body 1 to support electrical equipment. A monopile top flange 16 is also provided at the top of the monopile foundation body 1 for connecting to the upper wind turbine tower. Specifically, it also includes a crane 5 and a cage 4. The crane 5 is fixed to the outer platform 6 at the top of the monopile foundation body 1, and the cage 4 is raised and lowered by the crane 5 for personnel to access the platform. The berthing system in this embodiment does not include ladders, effectively preventing unauthorized personnel from climbing to the wind turbine platform via the berthing facilities. Specifically, it also includes a mooring bollard 3 for securing the mooring lines after the ship berths. In one embodiment, the mooring bollard 3 is connected to the monopile foundation body 1 via a flange.

[0028] The working principle of the mooring system for offshore wind turbine monopile foundations in this embodiment is as follows: The monopile foundation body 1 is connected to the external seawater through a turning hole 8, and the water level inside the pile changes synchronously with the external sea level. The buoy 11 floats on the water surface inside the pile. When the sea level rises, the water level inside the pile rises, and the buoy 11 rises accordingly, moving the hollow rubber fender 2 upwards via a towing rope 9. When the sea level falls, the water level inside the pile falls, and the buoy 11 sinks accordingly, causing the hollow rubber fender 2 to move downwards under its own weight. Thus, the hollow rubber fender 2 moves up and down via the towing rope, always remaining above the water surface, and automatically adjusting its height according to water level changes to ensure compatibility with vessels at different water levels.

[0029] When a ship impacts the hollow rubber fender 2, the fender is compressed, reducing the volume of the internal cavity, and air is expelled at high speed from the vent 15. The air encounters flow resistance as it passes through the vent 15, converting the impact energy into heat energy, thus creating aerodynamic damping. Because most of the impact energy is dissipated through exhaust rather than stored in the rubber material of the fender, less elastic potential energy is stored inside the fender when the ship leaves, significantly reducing the ship's rebound kinetic energy and achieving a low-rebound effect. After the ship leaves, the fender springs back to its original position, and external air re-enters the cavity through the vent 15.

[0030] Specifically, in one embodiment, taking a 500-ton displacement maintenance vessel with a berthing speed of 0.45 m / s as an example, a berthing simulation test was conducted using the berthing system of this embodiment. The test results show that during the impact, the air inside the hollow rubber fender 2 is discharged at high speed from the vent 15, converting approximately 50% to 70% of the impact kinetic energy into heat energy dissipation through airflow resistance. Compared to a traditional inflatable rubber fender of the same size, the gas inside the hollow rubber fender 2 of this embodiment is connected to the atmosphere, resulting in a 20% to 30% reduction in peak reaction force and a 40% to 60% reduction in ship rebound speed when absorbing the same amount of energy. Simultaneously, when the tide level changes, the vertical traction device automatically adjusts the height of the hollow rubber fender 2, ensuring that the fender is always at a height position matching the ship's height.

[0031] The above are merely preferred embodiments of this application. It should be noted that this application is not limited to the above embodiments. For those skilled in the art, several improvements and modifications can be made without departing from the principles of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should also be considered within the scope of protection of this application.

Claims

1. A mooring system for offshore wind turbine monopile foundations, characterized in that, include: The monopile foundation body (1) has a floating pontoon (11) inside. Hollow rubber fender (2); A lateral traction device is used to install the hollow rubber fender (2) onto the monopile foundation body (1); The vertical traction device includes a traction rope (9), an upper steering device (10), and a steering hole (8); the upper steering device (10) is fixed to the outer wall of the monopile foundation body (1) and located above the hollow rubber fender (2); the steering hole (8) is opened on the wall of the monopile foundation body (1) and located below the hollow rubber fender (2), and the steering hole (8) connects the interior of the monopile foundation body (1) with the external seawater; one end of the traction rope (9) is connected to the hollow rubber fender (2), and the other end is turned upward through the upper steering device (10) and then passed downward through the steering hole (8) into the interior of the monopile foundation body (1) and connected to the buoy (11); the hollow rubber fender (2) adaptively adjusts its height according to the water level.

2. The mooring system for offshore wind turbine monopile foundations according to claim 1, characterized in that, The hollow rubber fender (2) has a cavity inside and a vent (15) communicating with the cavity.

3. The mooring system for offshore wind turbine monopile foundations according to claim 1, characterized in that, The number of hollow rubber fenders (2) is 2 to 4, and they are evenly arranged along the circumference of the monopile foundation body (1).

4. The mooring system for offshore wind turbine monopile foundations according to claim 1, characterized in that, The lateral traction device includes two traction components, which are symmetrically arranged on both sides of the hollow rubber fender (2). Each traction component includes a spring (12), a connecting rope (13), and an anchor point (14). One end of the connecting rope (13) is connected to the hollow rubber fender (2) through the spring (12), and the other end of the connecting rope (13) is fixed to the anchor point (14). The anchor point (14) is located on the monopile foundation body (1).

5. The mooring system for offshore wind turbine monopile foundations according to claim 2, characterized in that, The vent (15) of the cavity rubber fender (2) is located at the upper and lower ends of the cavity rubber fender (2).

6. The mooring system for offshore wind turbine monopile foundations according to claim 1, characterized in that, The hollow rubber fender (2) is provided with stiffening ribs inside.

7. The mooring system for offshore wind turbine monopile foundations according to claim 1, characterized in that, The hollow rubber fender (2) has layers of rubber material embedded with rubber-coated curtain fabric, and the adjacent layers of rubber-coated curtain fabric are laid at an intersecting angle.

8. The mooring system for offshore wind turbine monopile foundations according to claim 7, characterized in that, The adhesive-coated curtain fabric has 2 to 3 layers.

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