Offshore wind turbine pile recovery device and recovery method thereof

Abstract

The invention provides an offshore wind turbine pile recovery device and a recovery method thereof.The offshore wind turbine pile recovery device comprises a floating body and an inner ring floating body connected to the floating body, a sea chest is arranged on one end face of the floating body, and a plurality of cabins which are not communicated with one another are arranged in the floating body to adjust ballast and draught; the inner ring floating body comprises a floating box, a clinging piece containing groove is formed in the inner ring of the floating box, the clinging piece containing groove is used for containing a clinging piece so that the clinging piece can be attached to a foundation pile, a vibration piece is connected to the floating box, a supporting piece is connected to the vibration piece, and a welding ring is arranged on the supporting piece and used for transmitting periodic upward pulling force to the foundation pile. In this way, the technical problems that the tidal energy utilization rate is low, pile-soil adhesion breaking is not thorough, and multi-specification pile diameter self-adaption is achieved are solved, efficient and lossless pile foundation recycling is achieved, and the operation cost and the ecological influence are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine pile recovery, and particularly relates to an offshore wind turbine pile recovery device and a recovery method thereof. Background Art

[0002] With the large-scale development of offshore wind power, a large number of early-built offshore wind turbines are gradually entering the retirement period, and the efficient and complete recovery of foundation piles has become a technical problem urgently to be solved in the industry. At present, the difficulty in the disassembly of offshore wind turbines lies in the recovery of foundation piles. An offshore wind turbine pile with a self-weight of about 1000t can have a foundation uplift force of 5000 - 10000t or higher, depending on the pile foundation design. Traditional pile foundation recovery methods mainly adopt technologies such as directly pulling piles with floating cranes, underwater cutting and segmental removal, and vibration jacking, etc., but these technologies have significant limitations:

[0003] 1. Limited operation ability of floating cranes: The lifting capacity of large floating cranes is severely restricted by sea conditions (such as waves and flow velocity). Especially in deep water areas or scenarios of large-diameter pile foundations (diameter ≥ 5m), it is difficult for floating cranes to provide continuous and stable pile pulling force, and the single-day rental cost is as high as several million yuan, with a relatively high cost;

[0004] 2. Damage to pile structure: Although underwater cutting can disassemble the pile foundation, it causes the materials to be unable to be recycled as a whole, and there are environmental risks such as oil leakage and metal debris pollution during the cutting process;

[0005] 3. Low efficiency of vibration pile pulling: Although existing vibration devices (such as vibration hammers) can break the pile-soil adhesion, their vibration force transmission path is single and they cannot cooperate with the buoyancy system, resulting in an energy utilization rate of less than 30%. The hydraulic hammers in the process all use gravity to drive piles, which is irreversible. And the power of the vibration hammer that uses vibration to fluidize the soil to reduce friction is still unable to achieve the pile pulling of large-diameter steel pipe piles. Therefore, in the past construction, the upper half was lifted out after cutting 2 meters below the mud surface, and the part below the mud surface will inevitably cause irreversible impacts on the environment of this sea area and subsequent development, and at the same time cause resource waste and lack of dynamic utilization of tidal energy;

[0006] 4. Poor adaptability: The structure of traditional buoyancy pile pulling devices is fixed, it is difficult to adapt to different pile diameters, and the ballast adjustment accuracy is low. Often, uneven gaps between the floating body and the pile body cause eccentric load jamming.

[0007] In recent years, the industry has tried to improve the integrated technology of buoyancy and mechanical pile pulling to solve the above technical problems. For example, a technical solution of a modular floating box structure has been proposed, but the rigid fixation between the floating body and the pile body depends on it, and the pile diameter error cannot be compensated, and the vibration decoupling function is not integrated, and the pile-soil adhesion breaking is not complete; Another technical solution proposed adopts the cooperation of hydraulic jacking and buoyancy, but does not combine the dynamic optimization of ballast with the tidal cycle, resulting in a single-tide pile pulling stroke of less than 1m.

[0008] The disclosure of the above background art content is only for assisting in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application, nor will it necessarily provide technical guidance. Without clear evidence indicating that the above content was publicly available before the filing date of this patent application, the above background art should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0009] In order to solve technical problems such as low utilization rate of tidal energy, incomplete breaking of pile - soil adhesion, and adaptability to multiple specifications of pile diameters, the present invention proposes an offshore wind turbine pile recovery device and its recovery method, which solve technical problems such as low utilization rate of tidal energy, incomplete breaking of pile - soil adhesion, and adaptability to multiple specifications of pile diameters, so as to achieve efficient and non - destructive recovery of the pile foundation, reduce operation costs and ecological impacts.

[0010] To achieve the above object, the technical solution of the present invention is as follows:

[0011] On the one hand, the present invention provides an offshore wind turbine pile recovery device, including: a floating body and an inner - ring floating body connected to the floating body. A subsea gate is provided on one end face of the floating body, and a plurality of non - communicating chambers are provided inside the floating body to adjust the ballast of the floating body.

[0012] The inner - ring floating body includes: a floating box. A tight - fitting member placement groove is provided inside the floating box, which is used to place a tight - fitting member to fit the foundation pile. A vibrating member is connected to the floating box, a supporting member is connected to the vibrating member, and a welding ring is provided on the supporting member for transmitting a periodic upward pulling force to the foundation pile.

[0013] The present invention proposes an offshore wind turbine pile recovery device and its recovery method, which solve technical problems such as low utilization rate of tidal energy, incomplete breaking of pile - soil adhesion, and adaptability to multiple specifications of pile diameters, so as to achieve efficient and non - destructive recovery of the pile foundation, reduce operation costs and ecological impacts.

[0014] As a preferred technical solution, the floating body includes: a first floating body and a second floating body. Upper and lower buckles matching the upper and lower card slots of the first floating body are provided on the circumferential wall of the second floating body, and a guiding structure is provided around the buckles.

[0015] As a preferred technical solution, the first floating body and the second floating body are fixedly connected to the inner - ring floating body through a clamping plate.

[0016] As a preferred technical solution, a winch is provided on the other end face of the first floating body, a mooring post is provided on the other end face of the second floating body, and the winch is connected to the mooring post through a rope.

[0017] As a preferred technical solution, the first floating body and the inner ring of the second floating body are both provided with a concave pressure-bearing platform. The inner ring floating body is arranged on the pressure-bearing platform and connected to the pressure-bearing platform. The inside of the pressure-bearing platform is provided with an annular clamping groove and a rectangular clamping groove, and the annular clamping groove and the rectangular clamping groove are used to limit the radial and circumferential movement of the inner ring floating body.

[0018] As a preferred technical solution, each of the cabins is communicated with the outlet of seawater through the sea gate.

[0019] As a preferred technical solution, an outer bottom plate is provided on one end face of the sea gate, a suction port is provided on the other end face of the sea gate, and a filter is provided between the outer bottom plate and the suction port.

[0020] As a preferred technical solution, pumps and pipelines are provided between the cabins for mutual water transfer and for adjusting the ballast of the floating body by sucking water and / or draining water from the sea gate.

[0021] As a preferred technical solution, at least four anchor cables are connected to the peripheral wall of the outer circle of the floating body.

[0022] On the other hand, according to the recovery method of the offshore wind turbine pile recovery device described in any one of the above, the method includes the following steps:

[0023] S1 Anchor and position the first floating body and the second floating body on both sides of the foundation pile along the water flow direction. The first floating body is located on the upstream side of the water flow, and the second floating body is located on the downstream side of the water flow;

[0024] S2 Use the winch on the first floating body to tow the mooring post on the second floating body, and synchronously adjust the ballast of the first floating body to adjust the draft, so that the buckle of the second floating body is inserted into the clamping groove of the first floating body and then drain water for docking to form an integral floating body structure;

[0025] S3 Adjust the four-anchor positioning of the integral floating body structure to make the circumferential gap between the floating body and the foundation pile uniform;

[0026] S4 Increase the ballast of the floating body to the maximum draft before the lowest tide level, connect the welding ring to the foundation pile, and synchronously adjust the ballast during connection to keep the relative height between the floating body and the foundation pile constant;

[0027] S5 Adjust the position of the floating body during high tide so that the support member presses tightly against the welding ring, and insert the close-fitting member so that the close-fitting member placement groove is locked with the foundation pile;

[0028] S6 Start the vibrating member and monitor the draft of the floating body in real time. Combine the high tide buoyancy and the periodic vibration force to pull out the pile, and at the same time adjust the ballast through the sea gate to control the rising speed of the foundation pile;

[0029] S7 Drain the water in each cabin of the floating body before the high tide level to obtain the maximum buoyancy stroke;

[0030] S8 continues with the next cycle until the pile extraction force is less than the lifting capacity of the floating crane. The foundation pile is hoisted onto the transport ship by the floating crane, and the device is transferred to the next construction position.

[0031] The offshore wind turbine pile recovery device and its recovery method provided by the present invention have the following beneficial effects:

[0032] 1) Solve technical problems such as low tidal energy utilization rate, incomplete breaking of pile-soil adhesion, and adaptability to multiple pile diameters, so as to achieve efficient and non-destructive recovery of the pile foundation, reduce operation costs and ecological impacts;

[0033] 2) Multiple independent ballast compartments are arranged inside the floating body, and rapid ballasting or de-ballasting is achieved through the sea chest for seawater exchange. During the tidal cycle, the device can actively adjust the draft. In the flood tide stage, the ballast water is reduced to increase the height of the floating body and avoid interruption of operations caused by being submerged by the tide. In the ebb tide stage, the ballast water is increased to maintain stable contact with the foundation pile. This design extends the operation window period to the entire tidal cycle, significantly improving the equipment utilization rate. In addition, the nested design of the inner floating body and the outer floating body forms a double stable surface, and can still maintain close fitting to the pile body under the action of waves, reducing the risk of operation interruption caused by sea condition fluctuations, and solving the technical problem of low tidal energy utilization rate;

[0034] The vibrating member transmits the vibration to the welding ring through the support member. Not only does the vibration energy destroy the cohesion of the soil around the pile, but the vibration and the periodic upward pulling force (adjusted by ballast water or applied by an external winch) form a "vibration-pulling" coupling, avoiding the peak stress of traditional static pile extraction, and gradually de-bonding the pile-soil interface, solving the technical problem of incomplete breaking of pile-soil adhesion;

[0035] The placing groove for the close-fitting member adopts a replaceable design, supporting a variety of close-fitting member configurations. The close-fitting member includes: wedge-shaped blocks and other forms of close-fitting members to adapt to the pile diameters of multiple specifications of foundation piles, solving the technical problem of adaptability to multiple pile diameters;

[0036] Through the trinity design of "dynamic buoyancy adjustment - vibration breaking of soil - adaptive fitting", the device realizes compatibility with complex marine environments, fine control of pile-soil interaction, and universality for multiple specifications of pile foundations, providing a green solution with better technical economy for the decommissioning of offshore wind turbines.

[0037] 3) The present invention provides a recovery method for an offshore wind turbine pile recovery device. Through precise anchor position planning, welding is carried out at the lowest tide level using the periodicity of the tide, and the floating body is emptied at the high tide level in the front row, maximizing the buoyancy travel. The construction window period is extended to the entire tidal cycle. Dynamic ballast regulation is adopted (initial docking → welding locking → vibrating pile extraction), compensating for the pile-soil viscous effect and buoyancy change in real time. Through the superposition effect of the dynamic load formed by the vibration of the vibrating part and the tidal buoyancy, the cohesion of the pile-soil interface is reduced. Through the integration of innovative technologies such as tidal energy utilization, dynamic ballast regulation, and intelligent vibration coupling, the efficient, safe, and green recovery of the wind turbine pile foundation is achieved. Brief Description of the Drawings

[0038] Figure 1 It is a schematic structural diagram of an offshore wind turbine pile recovery device provided by the present invention;

[0039] Figure 2 It is a cross-sectional view of an offshore wind turbine pile recovery device provided by the present invention;

[0040] Figure 3 It is a partial schematic structural diagram of an offshore wind turbine pile recovery device provided by the present invention;

[0041] Figure 4 It is a schematic structural diagram of the first floating body in an offshore wind turbine pile recovery device provided by the present invention;

[0042] Figure 5 It is a schematic structural diagram of the second floating body in an offshore wind turbine pile recovery device provided by the present invention;

[0043] Figure 6 It is a schematic structural diagram of the inner ring floating body in an offshore wind turbine pile recovery device provided by the present invention;

[0044] Figure 7 It is an assembly flow chart of an offshore wind turbine pile recovery device provided by the present invention;

[0045] Wherein: 1 - floating body; 2 - inner ring floating body; 3 - floating box; 4 - placement groove for close-fitting parts; 5 - vibrating part; 6 - support part; 7 - welding ring; 8 - foundation pile; 9 - first floating body; 10 - second floating body; 11 - buckle; 12 - clamping groove; 13 - winch; 14 - bollard; 15 - rope; 16 - bearing platform; 17 - annular clamping groove; 18 - rectangular clamping groove; 19 - sea bottom door; 20 - outer bottom plate; 21 - suction port; 22 - filter; 23 - anchor cable; 24 - close-fitting part. Detailed Description of the Embodiment

[0046] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0047] As Figures 1-6As shown in the figure, the present invention provides an offshore wind turbine pile recovery device, including: a floating body 1 and an inner floating body 2 connected to the floating body 1. One end face of the floating body 1 is provided with a sea bottom door 19. The interior of the floating body 1 is provided with a plurality of non - communicating compartments to adjust the ballast of the floating body 1;

[0048] The inner floating body 2 includes: a floating box 3. An inner - circle fitting - piece placement groove 4 is provided inside the floating box 3. The inner - circle fitting - piece placement groove 4 is used to place a fitting piece 24 to fit against the foundation pile 8. A vibrating member 5 is connected to the floating box 3. A supporting member 6 is connected to the vibrating member 5. A welding ring 7 is provided on the supporting member 6, which is used to transmit a periodic upward pulling force to the foundation pile 8.

[0049] The present invention proposes an offshore wind turbine pile recovery device and its recovery method, which solve technical problems such as low utilization rate of tidal energy, incomplete breaking of pile - soil adhesion, and adaptability to multiple - specification pile diameters, so as to achieve efficient and non - destructive recovery of the pile foundation, reduce operation costs and ecological impacts.

[0050] Preferably, as Figures 3-4 shown, the floating body 1 includes: a first floating body 9 and a second floating body 10. The circumferential wall of the second floating body 10 is provided with upper and lower buckles 11 that match the upper and lower card slots 12 of the first floating body 9. A guiding structure is provided around the buckles 11; the guiding structure guides the buckles 11 to quickly align with the card slots 12 during the assembly process, avoiding damage or inability to engage of the buckles 11 caused by position deviation during installation, and improving the assembly efficiency; the guiding structure also ensures that the buckles 11 enter the card slots 12 at the correct angle and position, avoiding skew or unilateral force, thereby enhancing the connection stability and reducing the risk of loosening caused by vibration or water flow impact during long - term use.

[0051] Preferably, as Figure 1 shown, the first floating body 9 and the second floating body 10 are fixedly connected to the inner floating body 2 through a clamping plate (not shown). The clamping plate (not shown) tightly connects the three floating bodies through multi - point fixation to form an overall framework; this design can effectively resist lateral / longitudinal shear forces generated by water flow impact, wave loads, or external collisions, avoiding relative displacement or separation between the floating bodies, and is especially suitable for dynamic water area environments.

[0052] Preferably, as Figure 1 and Figures 3-4As shown, a winch 13 is provided on the other end face of the first floating body 9, and a bollard 14 is provided on the other end face of the second floating body 10. The winch 13 is connected to the bollard 14 through a rope 15. By winding in and out the rope 15 with the winch 13, the relative distance between the two floating bodies can be accurately controlled. For example, when the water level changes, affected by tides or due to operation requirements, the layout of the floating bodies can be quickly adjusted to adapt to different working conditions (such as ship docking, equipment hoisting). Under the action of strong water currents, wind waves or operation loads, the winch can adjust the rope tension in real time to form an active restraint system. This can not only limit the lateral / longitudinal displacement of the floating bodies, but also optimize the force on the overall structure through pre-tension distribution to enhance the anti-overturning ability. When the floating bodies are transported over long distances or assembled on site, the winch can be used as a traction power source. Through the cooperation of the rope 15 and the bollard 14, accurate docking or separation of the floating bodies on the water surface can be achieved, reducing the dependence on large auxiliary equipment.

[0053] Preferably, as Figures 3-4 shown, concave pressure-bearing platforms 16 are provided on the inner circles of both the first floating body 9 and the second floating body 10. The inner floating body 2 is arranged on the pressure-bearing platform 16 and connected to the pressure-bearing platform 16. An annular slot 17 and a rectangular slot 18 are provided inside the pressure-bearing platform 16. The annular slot 17 and the rectangular slot 18 are used to limit the radial and circumferential movement of the inner floating body 2. The annular slot 17 limits the radial displacement of the inner floating body 2 (moving outward / inward in the horizontal plane) through geometric matching in the circumferential direction to ensure its coaxiality with the outer floating body. The rectangular slot 18 limits the circumferential rotation of the inner floating body 2 (rotating around the axis) through the contact of straight edges to prevent angular deviation under the action of torque. The double-slot design forms a three-dimensional restraint, locking the inner floating body 2 in the radial, axial and circumferential directions. This rigid connection can significantly improve the bending and torsion resistance of the combined floating body, especially suitable for scenarios of carrying large equipment or withstanding wave impacts. The symmetric distribution characteristics of the annular slot 17 can evenly disperse the concentrated loads (such as the weight of personnel / equipment) borne by the inner floating body 2 to the outer floating body, avoiding structural deformation or material fatigue caused by local stress concentration. The right-angle edge design of the rectangular slot 18 allows a certain floating space for the inner floating body 2 in the axial direction (vertical direction), which can compensate for manufacturing tolerances or thermal expansion and contraction effects, while ensuring close contact under dynamic loads. The guiding function of the annular slot 17 in cooperation with the limiting function of the rectangular slot 18 enables the inner floating body 2 to be quickly positioned through vertical hoisting without complex calibration tools. The modular design also supports local replacement, reducing maintenance costs.

[0054] Preferably, each compartment (not shown) is connected to the outlet of seawater (not shown) through the sea gate 19 to adapt to a complex hydrodynamic environment.

[0055] Preferably, as Figure 2As shown, an outer bottom plate 20 is provided on one end face of the sea chest 19, a suction port 21 is provided on the other end face of the sea chest 19, and a filter 22 is provided between the outer bottom plate 20 and the suction port 21; the filter 22 at the suction port 21 can intercept seaweeds, sediment and marine organisms, preventing sundries from entering the pump body and causing failures. The outer bottom plate 20 serves as the first barrier, further reducing the contact of large-volume foreign objects with the suction port and avoiding ballast failure caused by blockage.

[0056] Preferably, a pump (not shown) and pipelines (not shown) are provided between the compartments (not shown) for mutual water transfer and for adjusting the ballast of the floating body 1 by sucking and / or discharging water from the sea chest 19; each compartment (not shown) is independently equipped with a sea chest 19 and a pump (not shown), which can perform precise injection and drainage compensation for local load changes, avoiding the response lag of the traditional centralized ballast system; water transfer between the compartments (not shown) is achieved through pipelines, forming a "water tank connection network". For example, when one side compartment (not shown) is flooded due to a collision, the water volume can be quickly transferred to the empty compartment on the opposite side to prevent the structure from tilting.

[0057] Preferably, as Figure 1 shown, at least four mooring cables 23 are connected to the outer peripheral wall of the floating body 1; the multi-anchor point design disperses the mooring force to the peripheral wall of the floating body, avoiding local structural overload caused by single-point mooring.

[0058] As Figure 7 shown, according to the recovery method of the offshore wind turbine pile recovery device described in any one of the above, the following steps are included:

[0059] S1 Anchor and position the first floating body 9 and the second floating body 10 on both sides of the foundation pile 8 along the water flow direction. The first floating body 9 is located on the upstream side of the water flow, and the second floating body 10 is located on the downstream side of the water flow;

[0060] S2 Use the winch 13 on the first floating body 9 to tow the mooring post 14 on the second floating body 10, and synchronously adjust the ballast of the first floating body 9 to adjust the draft, so that the buckle 11 of the second floating body 10 is inserted into the card slot 12 of the first floating body 9 and then drain water for docking to form an overall floating body structure;

[0061] S3 Adjust the four-anchor positioning of the overall floating body structure to make the circumferential clearance between the floating body and the foundation pile 8 uniform;

[0062] S4 Increase the ballast of the floating body to the maximum draft before the lowest tide level, weld the welding ring 7 to the foundation pile 8, and synchronously adjust the ballast during welding to keep the relative height of the floating body 1 and the foundation pile 8 constant;

[0063] S5 When the tide is rising, adjust the position of the floating body so that the support member 6 abuts against the welding ring 7, and insert the close-fitting member 24 so that the close-fitting member placement groove 4 is locked with the foundation pile 8;

[0064] S6 Activate the vibration member 5 and monitor the draft of the floating body 1 in real time. Pull out the pile by combining the flood tide buoyancy and the periodic vibration force. At the same time, adjust the ballast through the sea chest 19 to control the rising speed of the foundation pile 8;

[0065] S7 Drain the water in each compartment of the floating body before the high tide level to obtain the maximum buoyancy stroke;

[0066] S8 Continue the next cycle until the pile pulling force is less than the lifting force that the floating crane can bear. Lift the foundation pile 8 to the transport ship by the floating crane and transfer the device to the next construction position.

[0067] The present invention provides a recovery method for a recovery device of an offshore wind turbine pile. Through precise anchor position planning, welding is carried out at the lowest tide level by using the periodicity of the tide, and the floating body is drained before the high tide level to maximize the buoyancy stroke. The construction window period is extended to the entire tidal cycle. Dynamic ballast regulation (initial docking → welding lock → vibration pile pulling) is adopted to compensate for the pile-soil viscous effect and buoyancy change in real time. Through the superposition effect of the dynamic load formed by the vibration of the vibration member and the tidal buoyancy, the cohesion of the pile-soil interface is reduced. Through the integration of innovative technologies such as tidal energy utilization, dynamic ballast regulation, and intelligent vibration coupling, the efficient, safe, and green recovery of the wind turbine foundation pile is realized.

[0068] As Figures 1-6 shown, the present invention provides a recovery device for an offshore wind turbine pile, which is composed of a first floating body 9, a second floating body 10, and an inner ring floating body 2; the main structures of the first floating body 9, the second floating body 10, and the inner ring floating body 2 are all steel enclosure structures. The bottom of the first floating body 9 and the bottom of the second floating body 10 are provided with sea chests 19. A plurality of non-connected compartments are arranged inside the first floating body 9 and inside the second floating body 10 for adjusting the ballast, maintaining the structural level, and being able to actively change the draft, so as to adjust the pile pulling force. The inner ring floating body 2 can be combined with the first floating body 9 or the second floating body 10 to form a semi-circular combined floating body. By replacing the inner ring floating body 2, the effect of adapting to different pile diameters can be achieved. After the combination is completed, the inner ring floating body 2 can be further fixedly connected with the first floating body 9 and the second floating body 10 through a clamping plate (not shown);

[0069] Among them, the first floating body 9 is of a semi-circular structure. A winch 13 is provided at the top of the first floating body 9. The inner ring floating body 2 is provided with a concave bearing platform 16, which is used to place and connect with the inner ring floating body 2. The bearing platform 16 is internally provided with a concave annular clamping groove 17 and a rectangular clamping groove 18 to prevent the relative radial and circumferential movement between the inner ring floating body 2 and the first floating body 9. The circumferential wall of the first floating body 9 is provided with upper and lower clamping grooves 12, and the circumferential wall of the second floating body 10 is provided with upper and lower clamping buckles 11. The upper and lower clamping buckles 11 are used to be clamped with the upper and lower clamping grooves 12. A guiding structure is provided around the clamping groove 12 to facilitate the offshore docking of the equipment. A mooring post 14 is provided at the top of the second floating body 10. The mooring post 14 is used to cooperate with the winch 13 at the top of the first floating body 9 through a rope 15 to achieve the precise docking or separation of the floating body 1 on the water surface;

[0070] Among them, the inner ring floating body 2 is composed of a floating box 3, a welding ring 7, a support member 6 and a vibration member 5. The inner ring of the floating box 3 is provided with a tight-fitting member placement groove 4, and the function of the tight-fitting member placement groove 4 is to place the tight-fitting member 24 during construction to ensure the close fit between the floating box 3 and the foundation pile 8. A vibration member 5 is fixed on the top of the floating box 3, and a support member 6 is fixed on the vibration member 5. The welding ring 7 can be fixed on the support member 6 through a rope 15 during transportation and is untied and welded on the foundation pile 8 during construction. During construction, the vibration member 5 is fixed on the top of the floating box 3, mainly providing a vibration force. The buoyancy is transmitted from the vibration member 5 to the support member 6 and then to the welding ring 7, so that the foundation pile 8 can obtain a periodic uplift force to break the adsorption force between the pile body and the seabed; solve technical problems such as low tidal energy utilization rate, incomplete breaking of pile-soil adhesion, and self-adaptation to multiple pile diameters, so as to achieve efficient and non-destructive recovery of the pile foundation, reduce operation costs and ecological impacts.

[0071] As Figure 7 shown, the present invention provides a recovery method for a recovery device of an offshore wind turbine pile, including the following steps:

[0072] S1 According to the pile diameter of the foundation pile 8 to be pulled out, make a suitable inner ring floating body 2, the inner diameter of which does not exceed the pile diameter to be driven by 30 cm, and prepare suitable tight-fitting members 24 and welding rings 7. The tight-fitting member 24 is preferably a wedge-shaped block. To save costs, when the buoyancy provided by the floating body 1 of the device is much greater than the pile pulling force, the vibration member 5 can also be omitted and the pile can be directly pulled out by the buoyancy of the floating body 1;

[0073] S2 Combine the inner ring floating body 2 with the first floating body 9 and the second floating body 10 respectively to form two semi-circular floating body structures, and tow the equipment to the vicinity of the offshore wind turbine position;

[0074] S3 anchors the floating bodies on both sides of the foundation pile 8, and the two floating bodies need to be positioned along the direction of the water flow. The combined floating body of the first floating body 9 and the inner circle floating body 2 is dragged to the upstream side of the water flow. After anchoring, slowly loosen the cable and stop about 5-10 meters away from the pile. The combined floating body of the second floating body 10 and the inner circle floating body 2 is dragged to the downstream side of the water flow and anchored;

[0075] S4: Fix the rope of the winch 13 on the first floating body 9 to the mooring post 14 of the second floating body 10, and slowly pull the second floating body 10 close to the first floating body 9 by the winch 13. At this time, the first floating body 9 is ballasted synchronously to increase the draft, and ensure that the slot 12 is lower than the buckle 11 for easy connection. When the buckle 11 is inserted into the slot 12, the first floating body 9 is drained, so that the slot 12 and the buckle 11 are successfully docked to form an integral structure; the equipment is positioned with four anchors, and the gap around the foundation pile 8 is adjusted until the gap is relatively uniform;

[0076] S5 adjusts the ballast to the maximum, and starts welding the welding ring 7 to the foundation pile 8 2-3 hours before the lowest tide level. The welding must ensure that the bottom of the welding ring 7 is horizontal, and multiple welding rings 7 are on the same horizontal plane. During the welding process, the first buoy 9 and the second buoy 10 synchronously control the ballast so that the relative height of the buoy 1 and the foundation pile 8 remains unchanged;

[0077] S6 When the next high tide comes (welding must be completed), adjust the position of the floating body 1 so that the support member 6 just supports the welding ring 7, record the draft of the four corners of the floating body 1 at this time, insert the close-fitting member 24, so that the floating body 1 and the foundation pile 8 are locked at the close-fitting member placement groove 4, and the close-fitting member placement groove 4 is preferably a V-shaped groove;

[0078] S7: After the water level rises slightly and the support member 6 and the welding ring 7 are completely locked, open the vibration member 5 and keep a record of the draft of the floating body at all times;

[0079] S8 When the water level of the floating body 1 is close to the required pile pulling force, it is necessary to synchronously ballast to control the speed of water level rise;

[0080] S9 The foundation pile 8 starts to move upward under the superposition of the equipment floating body 1 and the periodic vibration force, and rises slowly. At this time, the ballast needs to be controlled to control the speed of the foundation pile 8 rising slowly. Note that the pile pulling force of the foundation will gradually decrease as it rises. Therefore, it is necessary to find the size of the pile pulling force required at this time on the pile pulling force curve according to the length of the pile pulled out, and reduce the draft at the four corners simultaneously;

[0081] S10 controls the ballast volume of the floating body so that the ballast inside the floating body is emptied before the high tide level, thereby obtaining the maximum lifting stroke;

[0082] S11 continues the next cycle until the pile pulling force is less than the value that the floating crane can lift, and the foundation pile 8 is lifted to the transport ship by the floating crane, and the foundation recovery device is moved to the next machine position to continue construction;

[0083] Through precise anchor position planning, the use of tidal periodicity to weld at the lowest tide level and empty the floating body in the front row at high tide level to maximize the buoyancy travel, the construction window period is extended to the full tidal cycle. By adopting dynamic ballast control (initial docking → welding lock → vibrating pile extraction), the pile-soil viscous effect and buoyancy change are compensated in real time. Through the superposition effect of dynamic loads formed by the vibration of the vibrating part and tidal buoyancy, the cohesion of the pile-soil interface is reduced. Through the integration of innovative technologies such as tidal energy utilization, dynamic ballast control, and intelligent vibration coupling, the efficient, safe, and green recovery of the wind turbine pile foundation is realized.

[0084] It can be understood that the present invention is described through some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. Additionally, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein. All changes or equivalent replacements that fall within the scope of the claims of this application are included. Additionally, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments that fall within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. An offshore wind turbine pile recovery device, characterized in that: It comprises: a floating body and an inner ring floating body connected to the floating body, wherein one end surface of the floating body is provided with a seabed door, and the interior of the floating body is provided with a plurality of compartments which are not connected to each other to adjust the ballast of the floating body; The inner ring float includes: a buoyancy box, the inner ring of the buoyancy box is provided with a close-fitting piece placement groove, the close-fitting piece placement groove is used to place the close-fitting piece to fit the foundation pile, the buoyancy box is connected to a vibrating piece, the vibrating piece is connected to a supporting piece, and the supporting piece is provided with a welding ring for transmitting periodic upward pulling force to the foundation pile.

2. The offshore wind turbine pile recovery device according to claim 1, characterized in that: The floating body comprises: a first floating body and a second floating body, wherein the surrounding wall of the second floating body is provided with upper and lower buckles matching the upper and lower clamping grooves of the first floating body, and a guide structure is provided around the buckle.

3. The offshore wind turbine pile recovery device according to claim 2, characterized in that: The first floating body, the second floating body and the inner ring floating body are fixedly connected via a clamping plate.

4. The offshore wind turbine pile recovery device according to claim 2, characterized in that: A winch is provided on the other end surface of the first floating body, and a mooring post is provided on the other end surface of the second floating body. The winch is connected to the mooring post through a rope.

5. The offshore wind turbine pile recovery device according to claim 2, characterized in that: The inner circles of the first float and the second float are both provided with a concave pressure-bearing platform, the inner circle float is arranged on the pressure-bearing platform and connected to the pressure-bearing platform, and an annular groove and a rectangular groove are provided inside the pressure-bearing platform, and the annular groove and the rectangular groove are used to limit the radial and circumferential movement of the inner circle float.

6. The offshore wind turbine pile recovery device according to claim 1, characterized in that: Each of the cabins is connected to the seawater outlet through the seabed door.

7. The offshore wind turbine pile recovery device according to claim 6, characterized in that: An outer bottom plate is arranged on one end surface of the seabed door, a suction port is arranged on the other end surface of the seabed door, and a filter is arranged between the outer bottom plate and the suction port.

8. The offshore wind turbine pile recovery device according to claim 6, characterized in that: Pumps and pipelines are arranged between the compartments for transferring water to each other and adjusting the ballast of the floating body by sucking water and / or discharging water from the seabed door.

9. The offshore wind turbine pile recovery device according to claim 1, characterized in that: At least four anchor cables are connected to the outer peripheral wall of the buoy.

10. The method for recovering an offshore wind turbine pile recovery device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1 anchors and positions a first floating body and a second floating body on both sides of the foundation pile along the direction of the water flow, wherein the first floating body is located on the upstream side of the water flow and the second floating body is located on the downstream side of the water flow; S2 uses the winch on the first buoy to pull the mooring column on the second buoy, and simultaneously adjusts the ballast of the first buoy to adjust the draft, so that the buckle of the second buoy is inserted into the slot of the first buoy and then drained and docked to form the overall structure of the buoy; S3 adjusts the four anchor positions of the overall floating structure to make the circumferential gap between the floating body and the foundation piles uniform; S4 Increase the ballast of the floating body to the maximum draft before the lowest tide level, connect the welding ring to the foundation pile, and adjust the ballast simultaneously during the connection to keep the relative height between the floating body and the foundation pile constant; S5 When the tide is high, adjust the position of the floating body so that the supporting member presses against the welding ring, insert the close fitting member so that the close fitting member placement groove and the foundation pile are locked; S6 activates the vibration component and monitors the draft of the floating body in real time, and pulls out the piles by combining the buoyancy of the rising tide and the periodic vibration force. At the same time, the ballast is adjusted through the seabed gate to control the rising speed of the foundation piles; Before S7 high tide, drain the water from each compartment of the floating body to obtain the maximum buoyancy stroke; S8 continues the next cycle until the pile pulling force is less than the lifting force of the floating crane, and the foundation pile is hoisted to the transport ship by the floating crane, and the transfer device is transferred to the next machine position for construction.

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