Semi-submersible floating offshore wind turbine platform and method of construction

Abstract

The present application relates to offshore wind power technology field, disclose a semi-submersible floating offshore wind turbine platform and construction method.The present application is through the lower end of anchoring piece sets into structure, the process of rotating in and out is small to the disturbance of the soil body around the pile, the pile integrity is good, so that the same anchoring piece can be used between multiple platforms, the fixed pile position can be reused, avoid the material waste and the sea area occupation caused by the permanent abandonment of the traditional steel pile under the sea.The guide locking assembly is fixedly arranged on the floating body foundation, the anchoring piece is movably arranged in the vertical guide part and can be released, and a detachable connection structure is formed, so that the fixed device is standardized, universalized and reusable, and the construction cost of the wind power plant is greatly reduced.The guide locking assembly can selectively lock or release the anchoring piece, cooperate with the rotating structure, so that the anchoring piece can be actively released after temporary fixation, replace the traditional hammering forced pulling mode, avoid the risk of pile failure and pile jam caused by excessive friction, and ensure the smooth recovery of the anchoring piece.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power technology, specifically to a semi-submersible floating offshore wind turbine platform and its construction method. Background Technology

[0002] As nearshore wind farm resources become increasingly saturated, offshore wind power construction is accelerating its expansion into deep-sea areas. Semi-submersible floating wind turbine platforms, due to their strong adaptability to water depth and lack of strict limitations imposed by seabed geological conditions, have become one of the mainstream foundational forms for deep-sea wind power development. These platforms typically consist of a floating structure, upper turbine support columns, and mooring connections. Throughout the entire construction cycle, from onshore construction to offshore installation, the platform undergoes several high-risk operational phases, including turbine hoisting, mooring chain connection, and typhoon self-sustaining, placing stringent requirements on the platform's temporary positioning and fixation.

[0003] Currently, the temporary anchoring of semi-submersible floating wind turbine platforms at sea typically employs a combination of independent pile driving and cable tying. During construction, a large floating crane vessel is used to drive multiple independent cylindrical steel anchor piles one by one into the seabed at a predetermined depth below the mudline in the target area using hydraulic hammers. The semi-submersible floating platform is then towed to the vicinity of the pile location. High-strength cables are then used to secure the platform body to the top of the driven steel piles via guide rollers or temporary welded tying points on the platform, tightening them in multiple directions. The tension of the cables restrains the platform's horizontal drift and sway, thus achieving temporary anchoring during installation or typhoon avoidance periods.

[0004] However, after the anchor piles are driven into the seabed using hydraulic hammers, the enormous side friction and the plastic deformation caused by continuous hammering result in the anchor piles becoming firmly embedded in the surrounding soil, making them impossible to pull out and retrieve. This means that each floating wind turbine platform requires dedicated, non-reusable anchor piles, leading to significant waste of engineering materials. More importantly, once the mooring system (anchor chain connection) of a semi-submersible floating wind turbine platform is installed, the steel piles driven into the seabed cannot be removed and must remain abandoned on the seabed. This not only prevents subsequent platforms from reusing the same pile locations in the same area but also causes the temporary anchoring costs of the entire wind farm to increase linearly with the number of platforms, hindering the development of floating wind power. Summary of the Invention

[0005] This invention provides a semi-submersible floating offshore wind turbine platform and construction method to solve the problem that existing solutions cannot recover fixed piles, resulting in wasted materials due to the configuration of dedicated fixed piles and the inability to reuse pile positions.

[0006] In a first aspect, the semi-submersible floating offshore wind turbine platform provided by the present invention includes a floating body foundation, a guide and locking assembly, and anchors. The guide and locking assembly is fixed to the floating body foundation and has a vertical guide portion that can be selectively switched between a locked state and an unlocked state. The anchors are movably inserted into the vertical guide portion and have a screw-in structure at their lower end. When the anchors are subjected to force, they can move vertically relative to the guide and locking assembly and screw into the seabed in the forward direction or out of the seabed in the reverse direction. After the anchors are screwed into the target position, the guide and locking assembly locks them in place to restrict the movement of the floating body foundation relative to the seabed.

[0007] Beneficial effects: By incorporating a screw-in structure at the lower end of the anchor, and allowing the anchor to rotate out of the seabed relative to the guide locking assembly under stress, the screw-in and screw-out processes minimize disturbance to the surrounding soil and maintain the structural integrity of the pile. The same anchor can be reused at multiple platform installation points, and the fixed pile location can be reused by subsequent platforms, avoiding the material waste and marine occupation issues associated with the permanent abandonment of steel piles on the seabed in traditional methods. Furthermore, by fixing the guide locking assembly to the floating foundation, and allowing the anchor to be moved through the vertical guide section and released, a detachable connection structure is formed between the anchor and the floating foundation. This allows the anchor to be transferred between different platforms, achieving standardization, universality, and reusability of the fixing device, significantly reducing wind farm construction costs. Furthermore, by selectively locking or releasing the components inserted into the guide locking assembly, combined with the setting of the screw-in structure at the lower end of the anchor, the anchor can actively release its embedment in the seabed by rotating in the opposite direction after completing the temporary fixing task, instead of relying on the traditional hammer-driven pile forcibly pulling it out. This avoids the operational risks of pile pulling failure due to excessive pile side friction and pile getting stuck on the seabed, and ensures the smooth recovery of the fixing device after subsequent processes such as anchor chain connection and wind turbine installation are completed.

[0008] In one optional embodiment, the guide locking assembly includes a connecting sleeve, a locking component, and a buffer component. The connecting sleeve is fixedly disposed on the float base, the locking component is disposed on the connecting sleeve, and the buffer component is disposed between the connecting sleeve and the anchor. The vertical guide portion is formed on the connecting sleeve.

[0009] Beneficial effects: By fixing the connecting sleeve to the floating body foundation, with the vertical guide portion directly formed inside the sleeve, the vertical movement trajectory of the anchor during installation is constrained. Even if the floating body foundation sways under the influence of wind, waves, and currents, the anchor can still be vertically guided to the seabed along the preset axis. This avoids the difficulties in hoisting and alignment, and the problems of pile misalignment leading to screw-out jamming, which are common in traditional processes. This ensures the smoothness and reliability of the anchor's forward and reverse screw-out movements. Furthermore, by placing the buffer assembly between the connecting sleeve and the anchor, when the anchor is subjected to wave period loads or wind turbine vibrations, the buffer assembly can effectively absorb the radial and axial impact kinetic energy transmitted from the anchor to the connecting sleeve. It also blocks the direct transmission of high-frequency vibrations to the floating body foundation, preventing the locking assembly from seizing or loosening due to rigid collisions. Additionally, it extends the service life of the guide locking assembly, allowing for reuse. Then, by using a locking component on the connecting sleeve to hold the anchor, and a buffer component located between the two to form a flexible spacer layer, a synergistic structure of rigid locking and flexible buffering is formed. This allows the clamping force applied by the locking component to be evenly transmitted to the surface of the anchor through the buffer component. This can prevent stress concentration from causing local plastic deformation of the anchor and avoid affecting the accuracy of the next screwing in. It can also reduce the peak load impact under extreme sea conditions, ensuring that the displacement amplitude of the floating body foundation is strictly limited within the safety threshold during temporary fixing. This reduces the need for offshore hoisting and underwater manual intervention, and shortens the time from anchor landing to locking completion.

[0010] In one alternative embodiment, the locking assembly includes a hydraulic lifting cylinder for providing a locking driving force to switch the guide locking assembly between a locked state and an unlocked state.

[0011] Beneficial effects: By including a hydraulic lifting cylinder in the locking assembly, a stable and directionally controllable active driving force can be provided. When anchors are subjected to wave cyclic loads on the seabed for extended periods, additional viscous forces can easily arise between the locking assembly and the anchor due to fretting wear or debris intrusion. The hydraulic lifting cylinder can use its large-tonnage thrust to forcibly overcome the static friction and deformation locking forces between the locking assembly and the anchor, switching from the locked state to the unlocked state. This eliminates the risk of failure due to inability to release after locking, ensuring reliable unlocking of the anchor. The extension and retraction of the hydraulic lifting cylinder can be remotely controlled via hydraulic lines and a surface power station, eliminating the need for divers or underwater robots to operate the locking mechanism at close range. This allows the switching of the guide locking assembly between the locked and unlocked states to be completely free from underwater manual intervention, shortening the operation time for state switching, reducing the operational window at sea, and lowering the personal safety risks of underwater operations in harsh sea conditions. In addition, the output pressure of the hydraulic lifting cylinder can be steplessly adjusted according to preset working conditions. For example, under extreme working conditions such as typhoons, high pressure locking can be maintained to ensure sufficient friction to constrain the displacement of the floating body foundation; under normal installation conditions, the locking force can be reduced to reduce pre-pressure damage to the buffer components.

[0012] In one alternative embodiment, the buffer assembly is made of a high-damping, wear-resistant material to absorb and dissipate vibrational energy between the buoy base and the anchor in a locked state.

[0013] Beneficial effects: Because the high-damping wear-resistant material fills the space between the connecting sleeve and the anchor, forming a flexible isolation layer, when the anchor is subjected to typhoon or wave impact loads, this buffer layer can effectively attenuate the radial compressive force and axial impact peak transmitted from the anchor to the locking assembly. This prevents scratches, pits, or localized cold welding on the outer wall of the anchor due to rigid contact friction, protecting the surface integrity of the anchor and ensuring that it can still smoothly perform the reverse rotation out of the seabed after multiple locking-unlocking cycles. This eliminates the risk of the anchor being forced to be discarded due to surface wear causing rotation jamming. Simultaneously, by using the high-damping wear-resistant material, its energy dissipation characteristics can convert the low-frequency, large-amplitude swaying motion of the floating foundation under wave action into heat energy within the material for dissipation. In the locked state, the rigid transmission path of wave excitation to the platform body is cut off, reducing the residual sway amplitude of the floating foundation. This provides a highly stable working platform for wind turbine blade hoisting and positioning and mooring anchor chain flange connection, solving the pain points of traditional rigid fixing methods such as wave resonance and difficult positioning.

[0014] In one optional embodiment, the buffer assembly is further provided with a monitoring structure, which is used to collect at least one of the following data in real time: contact pressure, relative slippage, and locking force between the locking assembly and the anchor, and send it to an external receiving end.

[0015] Beneficial Effects: By integrating a monitoring structure within the buffer assembly, the contact pressure and locking force between the locking assembly and the anchor are directly measured, and the data is transmitted to an external receiver in real time. Operators can accurately determine whether the locking is in place based on the measured values, eliminating the risk of inadequate locking or damage to the anchor due to sea state interference or mechanical wear, ensuring reliable locking during each temporary fixing operation. Simultaneously, the monitoring structure continuously records locking force data during multiple temporary fixing operations, constructing a historical performance curve of the guide locking assembly. By analyzing the trend of locking force decay rate, maintenance personnel can determine whether the buffer assembly is experiencing material fatigue or wear degradation, thereby predicting whether the guide locking assembly still meets the design locking requirements, guiding intelligent operation and maintenance and reuse decisions.

[0016] In one optional embodiment, multiple sets of the guide locking assemblies are provided on the floating body, the multiple sets of guide locking assemblies are distributed at intervals along the circumference, and each guide locking assembly is respectively fitted with an anchor.

[0017] Beneficial Effects: Multiple sets of guide and locking assemblies are distributed circumferentially, forming a multi-point constraint system around the floating foundation. Compared to single-point or two-point fixing, this layout, through geometrically distributed anchoring, can effectively constrain the sway, pitch, roll, and bow degrees of freedom of the floating foundation simultaneously. During high-altitude wind turbine installation, this all-around attitude locking can reduce low-frequency slow drift motion induced by second-order wave forces, reducing the amplitude of platform deck motion to within the safe threshold allowed by the lifting equipment, thus solving the problem of significant rotational swaying of the platform even with eccentric fixation of a single pile. Furthermore, under extreme typhoon conditions, even if one set of anchors experiences a decrease in bearing capacity due to encountering seabed boulders or localized scouring, the remaining multiple fixing devices can still redistribute the load through circumferentially distributed geometric constraints, thereby maintaining the overall stability of the floating foundation.

[0018] In one alternative embodiment, the top of the anchor is provided with a connection interface for detachably connecting to an external force-applying device to transmit forward or reverse rotational force to the anchor.

[0019] Beneficial effects: The connection interface allows the external force application device to form a connection path with the anchor, transmitting torque in the forward direction to drive the anchor into the seabed and in the reverse direction to drive it out of the seabed. This transforms the traditional hammer-driven and forced-lift operation into a reversible, low-disturbance operation mode of screwing in and out, providing a basis for the repeated recycling of anchors. Furthermore, the detachable design of the connection interface allows for quick transfer of the same external force application device between different anchors. When the floating foundation is equipped with multiple sets of guide locking assemblies, the force application device can sequentially screw in each anchor without requiring a separate drive unit for each anchor, reducing the time spent by the lifting vessel repeatedly changing specialized tools at sea and improving the efficiency of multi-pile operations.

[0020] In one alternative embodiment, the semi-submersible floating offshore wind turbine platform further includes a towing member mounted on a guide locking assembly for connection to an external tugboat.

[0021] Beneficial effects: By directly mounting the towing component onto the existing load-bearing structure of the guide locking assembly, there is no need to set up a separate load-bearing component for the towing function, thus optimizing the platform deck space.

[0022] Secondly, the present invention also provides a construction method for a semi-submersible floating offshore wind turbine platform, applicable to the semi-submersible floating offshore wind turbine platform of the first aspect, comprising the following steps: towing the floating foundation to the target sea area; inserting the anchor into the vertical guide part, driving the anchor to move vertically downward and screwing it into the seabed mud surface to the target depth, then switching the guide locking assembly to the locking state, so as to lock the anchor into the guide locking assembly to restrict the movement of the floating foundation relative to the seabed; carrying out offshore operations while the floating foundation remains fixed; after completing the offshore operations, driving the anchor to rotate in the opposite direction, so that the screw-in structure is screwed out from the seabed mud surface in the opposite direction, and removing the anchor from the vertical guide part.

[0023] Beneficial effects: Since the construction method of the semi-submersible floating offshore wind turbine platform is applied to the semi-submersible floating offshore wind turbine platform in the first aspect, it has the same effect as the semi-submersible floating offshore wind turbine platform, which will not be elaborated here.

[0024] In one alternative implementation, the offshore operation is at least one of wind turbine hoisting operation, mooring chain connection operation, or typhoon self-sustaining standby operation. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments 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 from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the main structure of a semi-submersible floating offshore wind turbine platform provided in an embodiment of the present invention; Figure 2 A top-view schematic diagram of a semi-submersible floating offshore wind turbine platform provided in an embodiment of the present invention; Figure 3 for Figure 2 A cross-sectional schematic diagram of AA in the middle; Figure 4 for Figure 2 Cross-sectional schematic diagram of BB; Figure 5 A top-view diagram of the middle section of a semi-submersible floating offshore wind turbine platform provided in an embodiment of the present invention; Figure 6 This is a top view of the guide locking assembly in the locked state in a semi-submersible floating offshore wind turbine platform provided in an embodiment of the present invention. Figure 7 This is a top view of the guide locking assembly in the unlocked state of the semi-submersible floating offshore wind turbine platform provided in an embodiment of the present invention. Figure 8 This is a schematic diagram of the main structure of the anchorage in a semi-submersible floating offshore wind turbine platform provided in an embodiment of the present invention. Figure 9 A schematic flowchart illustrating the construction method of a semi-submersible floating offshore wind turbine platform provided in an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures: 1. Floating body foundation; 2. Guide locking assembly; 201. Connecting sleeve; 202. Locking assembly; 203. Buffer assembly; 204. Monitoring structure; 205. Annular gap; 3. Anchor; 301. Screw-in structure; 302. Connection interface; 4. Trailing components; 5. Fan; 6. Tower; 7. Mooring connectors. Detailed Implementation

[0028] 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, 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.

[0029] According to embodiments of the present invention, on one hand, a semi-submersible floating offshore wind turbine platform is provided, such as Figures 1 to 8 As shown, it includes a floating body foundation 1, a guide locking assembly 2, and an anchor 3.

[0030] Among them, the floating foundation 1 is a semi-submersible floating structure used to support the upper wind turbine 5 and tower 6, and can be towed and moved on the water surface.

[0031] The guide locking assembly 2 is fixed on the floating body base 1. It has a vertical guide part, such as a guide channel extending vertically, and can be selectively switched between a locked state and an unlocked state.

[0032] Anchor 3 is movably inserted into the vertical guide section, and its lower end is provided with a screw-in structure 301. For example, a helical blade or threaded section, so that when the anchor 3 is subjected to force, it can move vertically relative to the guide locking assembly 2 and screw into the seabed in the forward direction, or screw out of the seabed in the reverse direction. After the anchor 3 is screwed into the target position, it is locked using the guide locking assembly 2, temporarily fixing the floating body foundation 1 at a set position on the sea surface to restrict the movement of the floating body foundation 1 relative to the seabed.

[0033] By providing a screw-in structure 301 at the lower end of the anchor 3, and allowing the anchor 3 to rotate out of the seabed in the opposite direction to the guide locking assembly 2 after being subjected to force, the screw-in and screw-out processes cause little disturbance to the soil around the pile and maintain the integrity of the pile structure. The same anchor 3 can be reused between multiple platform installation points, and the fixed pile position can also be reused by subsequent platforms, avoiding the waste of materials and the problem of occupying sea areas caused by the permanent abandonment of steel piles on the seabed in traditional processes.

[0034] Furthermore, by fixing the guide locking assembly 2 to the floating body foundation 1, and the anchor 3 being movably inserted into the vertical guide and being releasable, a detachable connection structure is formed between the anchor 3 and the floating body foundation 1, allowing the anchor 3 to be used between different platforms. This achieves standardization, universality, and reusability of the fixing device, significantly reducing the construction cost of wind farms.

[0035] Furthermore, by selectively locking or releasing the components inserted into the guide locking assembly 2, combined with the setting of the lower end of the anchor 3 screwing into the structure 301, the anchor 3 can actively release its embedment in the seabed by rotating in the opposite direction after completing the temporary fixing task, instead of relying on the traditional hammer-driven pile forcibly pulling it out. This avoids the operational risks of pile pulling failure due to excessive pile side friction and pile stuck on the seabed, and ensures the smooth recovery of the fixing device after subsequent processes such as anchor chain connection and wind turbine 5 installation are completed.

[0036] It can be explained that the floating structure is a semi-submersible submersible, consisting of three buoys arranged in an equilateral triangle and cross braces connecting the buoys.

[0037] The upper wind turbine 5 column is a vertical cylindrical steel tower, and its bottom is connected to the main deck base at the top center of the floating structure through a thick-walled cast steel transition section. The upper end of the cast steel transition section has a butt joint with the same diameter as the upper wind turbine 5 column, and the lower end has an outwardly extending skirt. The skirt is fixed to the annular pad on the main deck base by a full penetration groove weld.

[0038] Furthermore, the skirt base is equipped with a cross-shaped shear-resistant partition to distribute the bending moment and shear force transmitted by the upper fan 5 columns to the main load-bearing components of the floating structure.

[0039] It should be noted that four diagonal bracing lugs are evenly arranged around the outer wall of the transition section. Each diagonal bracing lug is connected to the top of the three pontoons of the floating structure through steel pipe diagonal bracing to form a spatial triangular stable support system to resist the overturning moment and dynamic fatigue load generated by the operation of the wind turbine 5.

[0040] It should be noted that the guide locking assembly 2 is not specifically limited, and can be an integral cast sleeve structure, a segmented welded steel guide frame structure, or a composite material guide tube structure, etc.

[0041] Preferably, the steel connecting sleeve 201 structure is made of integral forging or thick-walled steel plate rolled and welded.

[0042] Specifically, the guide locking assembly 2 includes a connecting sleeve 201, a locking component 202, and a buffer component 203.

[0043] The connecting sleeve 201 is fixedly installed on the floating body foundation 1, for example, by penetrating the deck of the floating body foundation 1 and welding it to the main structural beam, or by connecting it to the pre-set base flange of the floating body foundation 1 using high-strength bolts. A vertical guide section is formed inside the connecting sleeve 201. The inner diameter of this channel is larger than the outer diameter of the anchor 3 to ensure that the anchor 3 is not obstructed during installation and can be effectively guided and constrained during vertical movement.

[0044] The locking assembly 202 is disposed on the connecting sleeve 201, such as on the side wall or top flange of the connecting sleeve 201, and is used to apply radial clamping force or axial clamping force.

[0045] The buffer component 203 is disposed between the connecting sleeve 201 and the anchor 3, preferably disposed within the annular gap 205 between the connecting sleeve 201 and the anchor 3, for absorbing and dissipating the vibration and impact energy transmitted from the anchor 3 to the connecting sleeve 201.

[0046] By fixing the connecting sleeve 201 to the floating body foundation 1, and forming the vertical guide part directly inside the sleeve, the vertical movement trajectory of the anchor 3 during the installation process is constrained. Even if the floating body foundation 1 sways under the action of wind, waves and currents, the anchor 3 can still be vertically guided into the seabed along the preset axis. This avoids the problems of difficult hoisting and centering and pile body deviation causing sticking when unscrewing in traditional processes, ensuring the smoothness and reliability of the anchor 3's forward screwing in and reverse screwing out actions.

[0047] Furthermore, by placing the buffer assembly 203 between the connecting sleeve 201 and the anchor 3, when the anchor 3 is subjected to wave period loads or the vibration of the wind turbine 5, the buffer assembly 203 can effectively absorb the radial and axial impact kinetic energy transmitted from the anchor 3 to the connecting sleeve 201, block the direct transmission of high-frequency vibration to the floating body foundation 1, avoid the locking assembly 202 from seizing or loosening due to rigid collision, and extend the service life of the guide locking assembly 2, enabling reuse.

[0048] Then, by using a locking component 202 on the connecting sleeve 201 to hold the anchor 3, and a buffer component 203 located between the two to form a flexible spacer layer, a synergistic structure of rigid locking and flexible buffering is formed. This allows the holding force applied by the locking component 202 to be evenly transmitted to the surface of the anchor 3 through the buffer component 203. This can prevent stress concentration from causing local plastic deformation of the anchor 3 and avoid affecting the accuracy of the next screwing in. It can also reduce the peak load impact under extreme sea conditions, ensuring that the displacement amplitude of the floating body foundation 1 is strictly limited within the safety threshold during the temporary fixing period. This reduces the need for offshore hoisting and underwater manual intervention, and shortens the time from the anchor 3 touching the bottom to the completion of locking.

[0049] It should be noted that the locking component 202 is not specifically limited, and can be a mechanical wedge-type locking mechanism, a hydraulic clamp-type locking mechanism, or an electromagnetic attraction-type locking mechanism, etc.

[0050] Preferably, a clamp-type locking mechanism driven by a hydraulic lifting cylinder is used.

[0051] Specifically, the locking assembly 202 includes a hydraulic lifting cylinder, a locking ring, and a guide slider.

[0052] Furthermore, the hydraulic lifting cylinder is used to provide locking drive force so that the guide locking assembly 2 switches between the locked state and the unlocked state.

[0053] During installation, the cylinder body of the hydraulic lifting cylinder is fixed to the outer wall bracket of the connecting sleeve 201, and the end of its piston rod is hinged to the drive arm of the locking ring. The locking ring is a split annular structure that surrounds the outside of the connecting sleeve 201 or is embedded in the wall of the connecting sleeve 201. Under the push of the hydraulic lifting cylinder, the locking ring can radially contract to hold the anchor 3 inserted in the connecting sleeve 201, so that the guide locking assembly 2 switches to the locked state; when the hydraulic lifting cylinder depressurizes in the reverse direction, the locking ring expands radially under the action of the return spring or its own elasticity, releasing the anchor 3, so that the guide locking assembly 2 switches to the unlocked state.

[0054] By including a hydraulic lifting cylinder in the locking assembly 202, a stable and directionally controllable active driving force can be provided. When the anchor 3 is subjected to wave cyclic loads on the seabed for a long time, additional viscous force may be generated between the locking assembly 202 and the anchor 3 due to fretting wear or the intrusion of debris. The hydraulic lifting cylinder can use its large tonnage thrust to forcibly overcome the static friction and deformation locking force between the locking assembly 202 and the anchor 3, and switch from the locked state to the unlocked state, eliminating the risk of failure that cannot be released after locking, and ensuring that the anchor 3 can be reliably unlocked.

[0055] Meanwhile, the extension and retraction of the hydraulic lifting cylinder can be remotely controlled via hydraulic pipelines and the surface power station, eliminating the need for divers or underwater robots to operate the locking mechanism at close range. This allows the switching between the locked and unlocked states of the guide locking assembly 2 to be completely free from underwater manual intervention, which not only shortens the operation time for state switching and reduces the window for offshore operations, but also reduces the personal safety risks of underwater operations in harsh sea conditions.

[0056] In addition, the output pressure of the hydraulic lifting cylinder can be steplessly adjusted according to preset working conditions. For example, under extreme working conditions such as typhoons, high pressure locking can be maintained to ensure sufficient friction to constrain the displacement of the floating body foundation 1; under normal installation conditions, the locking force can be reduced to reduce pre-pressure damage to the buffer assembly 203.

[0057] It should be noted that the buffer component 203 is not specifically limited, and can be a rubber pad layer, a polyurethane elastomer layer, a metal spring damper, or a combined composite buffer structure, etc.

[0058] Preferably, a high-damping wear-resistant material, such as a ring-shaped buffer pad made of high-damping wear-resistant rubber and fiber-reinforced composite material, is used.

[0059] Specifically, the buffer assembly 203 is annular in shape and is embedded in the annular groove on the inner wall of the connecting sleeve 201, or directly bonded to the inner wall surface of the connecting sleeve 201.

[0060] Furthermore, the buffer assembly 203 is arranged in at least two rings along the axial direction, corresponding to the upper and lower parts of the insertion section of the anchor 3, respectively, to ensure that the anchor 3 can maintain contact with the buffer assembly 203 at different penetration depths. The surface of the buffer assembly 203 facing the anchor 3 is provided with a wear-resistant layer, such as a sprayed ceramic particle or vulcanized wear-resistant rubber layer, to reduce the wear on the buffer body during the screwing in and out of the anchor 3.

[0061] Because the high-damping wear-resistant material is filled between the connecting sleeve 201 and the anchor 3 to form a flexible isolation layer, when the anchor 3 is subjected to typhoon or wave impact load, this buffer layer can effectively attenuate the radial extrusion force and axial impact peak value transmitted by the anchor 3 to the locking assembly 202, avoid the outer wall of the anchor 3 from scratches, pits or local cold welding caused by rigid contact friction, protect the surface integrity of the anchor 3, and ensure that it can still smoothly perform the reverse rotation out of the seabed after multiple locking-unlocking cycles, and prevent the anchor 3 from being forced to be discarded due to surface wear causing rotation jamming.

[0062] Meanwhile, by using high-damping wear-resistant materials, the low-frequency, large-amplitude swaying motion of the floating foundation 1 under the action of waves and currents can be converted into heat energy within the material and dissipated. In the locked state, the rigid transmission path of wave excitation to the main platform is cut off, reducing the residual sway amplitude of the floating foundation 1. This provides a highly stable working platform for the hoisting and alignment of the wind turbine blades 5 and the connection of the mooring anchor chain flange, solving the pain points of traditional rigid fixing methods such as resonance with waves and difficulty in alignment.

[0063] In one embodiment, a mooring connection 7 is also included.

[0064] It should be noted that the mooring connector 7 is not specifically limited and can be an embedded cast steel anchor chain cylinder, an external guide, or a rotatable bollard swivel, etc.

[0065] Preferably, a cast steel anchor chain cylinder structure that penetrates the main deck of the floating body foundation 1 is adopted.

[0066] Specifically, the mooring connection 7 is provided on the top or side of each pontoon of the floating structure, including an anchor chain tube that extends vertically through the deck, a guide roller at the tube opening, and an anchor chain stopper at the bottom of the tube.

[0067] In the temporary fixing process, after the fixing piles lock the floating foundation 1 to the sea surface, the horizontal drift and swaying motion of the floating foundation 1 are effectively suppressed. At this time, the mooring connector 7 is in a zero-displacement stable state. The operator can accurately introduce the end of the mooring anchor chain pre-laid on the seabed into the anchor chain cylinder through the guide roller, and complete the docking of the anchor chain with the sprocket inside the floating foundation 1 and the locking operation of the chain stopper at the cylinder opening.

[0068] After the initial connection of the mooring system is completed, the anchor piles are released to allow the platform to smoothly transfer the load to the permanent mooring system, avoiding the problems of continuous platform drift that lead to difficulties in anchor chain docking and accelerated wear of connectors in traditional processes.

[0069] It can be noted that the screw-in structure 301 is not specifically limited, and can be a continuous spiral rib, an intermittent spiral blade, or an internal spiral groove processed on the surface of the pile body.

[0070] Preferably, a continuous trapezoidal cross-section spiral rib structure is adopted, which is formed on the outer wall of the fixed pile entering the mud section.

[0071] Specifically, the fixed pile driving section is a cylindrical steel pile body, and its outer wall has spirally rising ribs formed within a certain height range from the pile tip upwards through machining or welding.

[0072] The spiral rib is set to rotate right-handed to match the forward rotation direction of the external force application device. When rotating forward, the rib exerts a downward cutting and squeezing effect on the seabed soil, increasing the penetration efficiency; when rotating in the reverse direction, the rib exerts an upward lifting and loosening effect on the soil, reducing the pull-out resistance.

[0073] Furthermore, a tapered guide section is provided at the starting end of the spiral rib (i.e., the pile tip). The outer wall of the guide section is not provided with ribs or the height of the ribs gradually decreases, so as to facilitate vertical alignment when the fixed pile initially touches the bottom and avoid the pile tip from deflecting due to the ribs directly contacting the hard seabed.

[0074] In one embodiment, the buffer assembly 203 is further provided with a monitoring structure 204, which is used to collect at least one of the following data in real time: contact pressure, relative slippage, and locking force between the locking assembly 202 and the anchor 3, and send it to an external receiving end.

[0075] It should be noted that the monitoring structure 204 is not specifically limited, and can be a resistance strain gauge pressure sensor, a fiber optic strain gauge sensor, an inductive displacement sensor, or a piezoelectric dynamic force sensor, etc.

[0076] Preferably, a fiber Bragg grating pressure-displacement composite sensor is used.

[0077] Specifically, the monitoring structure 204 is set inside the buffer assembly 203, for example, it is pre-embedded in the high damping rubber pad layer near the anchor 3, or a mounting hole is opened on the side wall of the connecting sleeve 201 at the position corresponding to the buffer assembly 203, and the sensor probe is inserted into the contact interface between the buffer assembly 203 and the anchor 3.

[0078] Furthermore, the monitoring structure 204 includes a contact pressure sensing unit, a relative slip sensing unit, and a locking force sensing unit. Each sensing unit is connected to an external receiver via a signal cable or a wireless transmission module. The external receiver is a field acquisition station located on the floating body foundation 1 or a server in a remote monitoring center.

[0079] By integrating a monitoring structure 204 inside the buffer assembly 203, the contact pressure and locking force between the locking assembly 202 and the anchor 3 are directly measured, and the data is sent to an external receiver in real time. Operators can accurately determine whether the locking is in place based on the measured values, eliminating the risk of damage to the anchor 3 due to insufficient locking force caused by sea conditions or mechanical wear, and ensuring reliable locking action during each temporary fixing operation.

[0080] Meanwhile, the monitoring structure 204 continuously records locking force data during multiple temporary fixing operations, which can construct a historical curve of the locking performance of the guide locking assembly 2. By analyzing the trend of the locking force decay rate, maintenance personnel can determine whether the buffer component 203 has experienced material fatigue or wear degradation, and thus predict whether the guide locking assembly 2 still meets the design locking requirements, guiding intelligent operation and maintenance and reuse decisions.

[0081] In one embodiment, multiple sets of guide locking assemblies 2 are provided on the floating body foundation 1. The multiple sets of guide locking assemblies 2 are distributed at intervals along the circumference, and each guide locking assembly 2 is respectively fitted with an anchor 3.

[0082] Multiple sets of guide locking assemblies 2 are distributed circumferentially, forming a multi-point constraint system in space around the floating foundation 1. Compared with single-point or two-point fixing, this layout, through geometrically distributed anchoring, can effectively constrain the degrees of freedom of the floating foundation 1, such as sway, pitch, roll, and bow. During the high-altitude hoisting operation of the wind turbine 5, this all-round attitude locking can reduce the low-frequency slow drift motion induced by the second-order force of waves, reduce the motion amplitude of the platform deck to within the safe threshold allowed by the hoisting equipment, and solve the problem of significant rotational swaying of the platform when the single pile is eccentrically fixed.

[0083] Meanwhile, under extreme typhoon conditions, even if one set of anchors 3 experiences a decrease in bearing capacity due to encountering seabed boulders or local scouring, the remaining sets of fixing devices can still redistribute the load through circumferentially distributed geometric constraints, thereby maintaining the overall stability of the floating body foundation 1.

[0084] It can be noted that the number of guide locking assemblies 2 set on the floating body foundation 1 is not specifically limited, and can be two, three, four or more sets.

[0085] Preferably, each floating body foundation 1 is provided with three sets of guide locking assemblies 2, which are evenly distributed at 120° intervals along the circumference of the floating body foundation 1, and each set of guide locking assemblies 2 is respectively fitted with an anchor 3.

[0086] In one embodiment, the top of the anchor 3 is provided with a connection interface 302, which is used to detachably connect to an external force-applying device to transmit forward or reverse rotational force to the anchor 3.

[0087] By setting up the connection interface 302, an external force application device can form a connection path with the anchor 3, transmitting torque in the forward direction to drive the anchor 3 into the seabed and transmitting torque in the reverse direction to drive it out of the seabed. This transforms the operation mode of hammering in and forcibly pulling out into a reversible, low-disturbance operation mode of screwing in and out, providing a basis for the repeated recycling of the anchor 3.

[0088] Meanwhile, the connection interface 302 adopts a detachable design, which allows the same set of external force application devices to be quickly transferred between different anchors 3. When the floating body foundation 1 is equipped with multiple sets of guide locking assemblies 2, the force application device can complete the screwing operation of each anchor 3 in sequence without the need to equip each anchor 3 with an independent drive unit, reducing the time consumption of the lifting vessel to repeatedly change special tools at sea and improving the efficiency of multi-pile operation.

[0089] It should be noted that the connection interface 302 is not specifically limited, and can be an internal hexagonal socket interface, an external spline interface, a flange bolt connection interface 302, or a hydraulic claw quick-connect interface, etc.

[0090] Preferably, a combination structure of internal hexagonal sleeve interface and hydraulic claw quick-connect interface is adopted.

[0091] Specifically, the connection interface 302 is located at the top center of the anchor 3, and includes a regular hexagonal concave hole and multiple claw slots evenly distributed around the concave hole.

[0092] External force-applying devices, such as the rotary drive head on a lifting vessel, have a hexagonal boss at their lower end that mates with an internal hexagonal hole and radially retractable claws. When the drive head is inserted into the connection interface 302, the hexagonal boss and the internal hexagonal hole form a circumferential transmission engagement, and the claws extend and engage in the slots to form an axial anti-disengagement connection, thereby establishing a torque transmission path between the external force-applying device and the anchor 3, which can transmit forward or reverse rotational force to the anchor 3.

[0093] Of course, in other alternative embodiments, the connection interface 302 at the top of the anchor 3 is replaced with a flange and center guide post combined connection device.

[0094] Specifically, it includes a circular upper flange, a vertical central guide post, and multiple drive pin holes evenly distributed along the circumference of the flange.

[0095] The outer diameter of the upper flange is larger than that of the fixed pile. The flange has circumferentially distributed bolt holes or slots for detachable fastening to external force-applying devices, such as the rotary drive head or hydraulic chuck on a lifting vessel, using high-strength bolts or hydraulic jaws. A central guide post extends upwards from the center of the flange, and its outer wall has a longitudinal keyway for a sliding key engagement with the guide sleeve at the lower end of the external force-applying device. This ensures that the fixed pile and the force-applying device rotate concentrically during torque transmission, preventing eccentric swaying. Reinforcing ribs are installed between the bottom surface of the flange and the top surface of the fixed pile, spaced circumferentially to evenly transmit the axial pressure and rotational torque applied by the external force-applying device to the entire fixed pile, preventing localized stress concentration that could lead to pile top deformation.

[0096] In one embodiment, the semi-submersible floating offshore wind turbine platform also includes a towing member 4, which is mounted on the guide locking assembly 2 for connection to an external tugboat.

[0097] By directly installing the towing component 4 onto the existing load-bearing structure of the guide locking assembly 2, there is no need to set up a separate load-bearing component for the towing function, thus optimizing the platform deck space.

[0098] It should be noted that there is no specific limitation on the towing component 4. It can be a welded towing lug, a bolted towing ring, or a retractable towing bollard, etc.

[0099] Preferably, a drag lug is integrally cast with the outer wall of the connecting sleeve 201.

[0100] Specifically, the towing component 4 is installed on the outer wall of the guide locking assembly 2. For example, at least two symmetrically arranged lugs are welded or integrally cast on the outer wall of the connecting sleeve 201. The lugs have round holes or slots for the towing cable to pass through. The towing component 4 and the guide locking assembly 2 are constructed together on land with the floating foundation 1, eliminating the need for separate load-bearing components for towing, optimizing platform deck space, and reducing the amount of welding work at sea. When the floating foundation 1 needs to be towed and moved, the towing cable of the external tugboat is directly attached to the towing lug, achieving safe and efficient towing.

[0101] According to an embodiment of the present invention, in another aspect, a construction method for a semi-submersible floating offshore wind turbine platform is also provided, which is applied to the semi-submersible floating offshore wind turbine platform of the first aspect.

[0102] like Figure 9 As shown, it includes the following steps: Using a tugboat, the towing component 4 on the floating base 1 is connected to the towing cable, and the floating base 1 is towed to the target sea area installation point and initially positioned.

[0103] Subsequently, the anchor 3 is lifted using a gantry crane and inserted into the vertical guide section.

[0104] Specifically, the upper end of the anchor 3 is connected to the drive head of the external force application device, the lower end of the anchor 3 is aligned with the vertical guide of the guide locking assembly 2, and it is slowly lowered so that the anchor 3 passes through the connecting sleeve 201 and contacts the seabed mud surface.

[0105] Subsequently, the external force application device is activated, driving the anchor 3 to move vertically downward and rotate in the forward direction. The lower end of the anchor 3 is screwed into the structure 301 to screw the anchor 3 into the seabed mud surface.

[0106] It should be noted that during the screwing process, the monitoring structure 204 collects data on the penetration depth, rotational torque, and sidewall contact pressure of the anchor 3 in real time, and transmits this data to an external receiver for operator reference. When the anchor 3 is screwed into the preset target depth, rotation and pressure are stopped.

[0107] Next, check whether the insertion depth of anchor 3 meets the design requirements. If the depth is insufficient due to changes in seabed geological conditions, continue rotating the drive until the target depth is reached.

[0108] Subsequently, the hydraulic lifting cylinder on the guide locking assembly 2 is activated, driving the locking ring to radially contract and tighten the anchor 3, thus switching the guide locking assembly 2 to the locked state. At this time, the buffer component 203 is compressed between the inner wall of the connecting sleeve 201 and the outer wall of the anchor 3, forming a flexible locking contact. The monitoring structure 204 continuously collects the locking force, contact pressure, and relative slippage. After confirming that the locking is in place and meets the design locking force requirements, the locking operation is completed.

[0109] Afterwards, offshore operations were carried out while the floating base 1 remained fixed.

[0110] Specifically: offshore operations include: wind turbine 5 hoisting operations, such as the high-altitude hoisting and docking of wind turbine 5 tower 6 and blades; mooring chain connection operations, such as the initial connection of mooring chains; or, self-storage standby operations before the arrival of a typhoon.

[0111] After completing the offshore operation, the hydraulic lifting cylinder is driven to reverse, and then the locking ring is driven to expand radially to release the anchor 3, so that the guide locking assembly 2 is switched to the unlocked state.

[0112] Subsequently, an external force-applying device is used to reconnect the connection interface 302 at the top of the anchor 3, applying a reverse rotational torque to drive the anchor 3 to rotate in the opposite direction, causing the screw-in structure 301 to rotate out of the seabed mud surface. During the rotation process, a uniform lifting speed is maintained until the anchor 3 is completely detached from the seabed mud surface.

[0113] Finally, the anchor 3 is lifted out of the vertical guide section by a crane vessel and retrieved onto the ship for reuse at the next installation point or platform. At this point, the floating foundation 1 returns to a free-floating state and can be towed to the next working position.

[0114] It should be noted that the same specification guide locking assembly 2 is used, and the standard-built anchors 3, such as fixing piles, are used. After the temporary fixing task of one platform is completed and the fixing pile is successfully pulled out, it can be transferred to the installation point of the next platform for reuse. There is no need to configure a brand new fixing pile for each platform.

[0115] This universal and modular design can significantly reduce the total cost of wind farm fixtures and steel consumption, while avoiding the marine occupation and ecological impact caused by the permanent abandonment of large numbers of steel piles on the seabed in traditional processes.

[0116] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A semi-submersible floating offshore wind turbine platform, characterized in that, include: Floating body foundation(1); A guide locking assembly (2) is fixed to the floating body base (1), which has a vertical guide and can be selectively switched between a locked state and an unlocked state; Anchor (3) is movably inserted into the vertical guide part, and its lower end is provided with a screw-in structure (301); When the anchor (3) is subjected to force, it can move vertically relative to the guide locking assembly (2) and rotate into the seabed in the forward direction or rotate out of the seabed in the reverse direction; The guide locking assembly (2) locks the anchor (3) after it is screwed into the target position to restrict the movement of the floating body foundation (1) relative to the seabed.

2. The semi-submersible floating offshore wind turbine platform according to claim 1, characterized in that, The guide locking assembly (2) includes a connecting sleeve (201), a locking component (202), and a buffer component (203). The connecting sleeve (201) is fixedly disposed on the floating body base (1), the locking component (202) is disposed on the connecting sleeve (201), and the buffer component (203) is disposed between the connecting sleeve (201) and the anchor (3). The vertical guide portion is formed on the connecting sleeve (201).

3. The semi-submersible floating offshore wind turbine platform according to claim 2, characterized in that, The locking assembly (202) includes a hydraulic lifting cylinder for providing a locking driving force to switch the guide locking assembly (2) between a locked state and an unlocked state.

4. The semi-submersible floating offshore wind turbine platform according to claim 2, characterized in that, The buffer assembly (203) is made of a high-damping wear-resistant material and is used to absorb and dissipate the vibration energy between the floating body base (1) and the anchor (3) in the locked state.

5. The semi-submersible floating offshore wind turbine platform according to claim 2, characterized in that, The buffer assembly (203) is also provided with a monitoring structure (204), which is used to collect at least one of the following data in real time: contact pressure, relative slippage, and locking force between the locking assembly (202) and the anchor (3), and send it to an external receiving end.

6. The semi-submersible floating offshore wind turbine platform according to claim 1, characterized in that, Multiple sets of guide locking assemblies (2) are provided on the floating body foundation (1). The multiple sets of guide locking assemblies (2) are distributed at intervals along the circumference, and each guide locking assembly (2) is respectively fitted with an anchor (3).

7. The semi-submersible floating offshore wind turbine platform according to claim 1, characterized in that, The top of the anchor (3) is provided with a connection interface (302), which is used to detachably connect with an external force-applying device to transmit positive or negative rotational force to the anchor (3).

8. The semi-submersible floating offshore wind turbine platform according to claim 1, characterized in that, It also includes a towing member (4), which is mounted on the guide locking assembly (2) for connection with an external tugboat.

9. A construction method for a semi-submersible floating offshore wind turbine platform, applicable to the semi-submersible floating offshore wind turbine platform as described in any one of claims 1 to 8, characterized in that, Includes the following steps: The floating base (1) will be towed to the target sea area; The anchor (3) is inserted into the vertical guide, and the anchor (3) is driven to move vertically downward and rotated into the seabed mud surface to the target depth. Then the guide locking assembly (2) is switched to the locking state so that the guide locking assembly (2) locks the anchor (3) to limit the movement of the floating body foundation (1) relative to the seabed. Offshore operations are carried out while the floating foundation (1) remains fixed. After completing the offshore operation, drive the anchor (3) to rotate in the opposite direction, so that the screw-in structure (301) is screwed out of the seabed mud surface in the opposite direction, and remove the anchor (3) from the vertical guide.

10. The construction method of the semi-submersible floating offshore wind turbine platform according to claim 9, characterized in that, Offshore operations include at least one of the following: wind turbine (5) hoisting operation, mooring anchor chain connection operation, or typhoon self-sustaining standby operation.

Images