Split jacket structure of offshore wind turbine and mounting method of split jacket structure

Abstract

The invention discloses an offshore wind turbine split jacket structure and a mounting method thereof. The offshore wind turbine split jacket structure comprises a lower jacket, and a steel pipe pile is fixed to the bottom of the lower jacket; a tower drum is mounted at the top of the upper jacket, and the upper jacket is mounted at the top of the lower jacket; the upper jacket and the lower jacket bracket are butted and fixed through a plurality of flange connecting nodes; the fixing assemblies are arranged between the flange connecting joints and the upper jacket and between the flange connecting joints and the lower jacket. The continuous linear guide pipe main limb pipe design is adopted for the connecting part, section mutation caused by geometric shape conversion in a traditional scheme is avoided, the structure stress state is effectively improved, and the load transmission efficiency and the overall structure performance are remarkably improved. Compared with grouting connection, the maintenance period after grouting does not need to be considered, and the construction period is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power engineering, and in particular to a split-type jacket structure for an offshore wind turbine and an installation method thereof. Background Art

[0002] Amidst the global energy transition, offshore wind power, as a sustainable, clean energy source, has become a strategic direction for adjusting the global energy mix. The offshore wind power industry is currently undergoing a dual transformation: deeper offshore and larger-scale installations. With increasing offshore distances and water depths, coupled with the continued growth of unit capacity, the geometric dimensions and structural weight of traditional integral jackets are increasing exponentially. This not only places extreme demands on the lifting capabilities of shipbuilding equipment but also leads to systemic challenges such as surging foundation costs and shrinking construction windows.

[0003] The split jacket structure uses modular decomposition technology to transform the overall structure into a standard unit that can be independently transported and installed, effectively breaking through the dual limitations of ship deck area and lifting capacity, and providing a feasible path for deep-sea wind power development. Among the existing split jacket solutions, grouting connection technology (such as utility models CN202321456517.2 and CN202321295737.1) has become the mainstream choice for achieving load transfer between modules due to its excellent installation tolerance. However, there is still room for improvement in the actual application of this technology: offshore grouting operations are limited by the material curing cycle and adaptability to the marine environment; at the same time, in order to meet the requirements of the lifting process, the connection area needs to adjust the inclined main limb pipe to a vertical transition. This geometric change may affect the continuity of load transfer. How to break through the existing limitations and develop an efficient and reliable new split connection structure has become a key technical bottleneck for reducing costs and increasing efficiency in deep-sea wind power.

[0004] Based on the above technical problems, the present invention provides a split-type jacket structure for an offshore wind turbine and an installation method thereof. Summary of the Invention

[0005] The object of the present invention is to provide a split-type jacket structure for an offshore wind turbine and an installation method thereof, so as to solve the problems existing in the prior art.

[0006] To achieve the above-mentioned object, the present invention provides the following solution: The present invention provides a split-type jacket structure for an offshore wind turbine, comprising:

[0007] A lower jacket frame, wherein a steel pipe pile is fixed at the bottom of the lower jacket frame;

[0008] An upper jacket, a tower is installed on the top of the upper jacket, and the upper jacket is installed on the top of the lower jacket;

[0009] Flange connection nodes, the upper jacket and the lower jacket support are fixed together by connecting with each other through a plurality of flange connection nodes;

[0010] A fixing assembly is respectively arranged between the flange connection node and the upper jacket and the lower jacket.

[0011] According to the split-type jacket structure of an offshore wind turbine provided by the present invention, the upper jacket includes a plurality of first supporting main legs, adjacent first supporting main legs are fixed by first diagonal braces, pile platforms are fixed to the top ends of the first supporting main legs, and the tower is fixed to the top surface of the pile platforms.

[0012] According to the split-type jacket structure of an offshore wind turbine provided by the present invention, the lower jacket includes a plurality of second supporting main legs, the first supporting main legs and the second supporting main legs are arranged in a one-to-one correspondence, adjacent second supporting main legs are fixed by second diagonal braces and horizontal braces, the bottoms of the second supporting main legs are fixed on the steel pipe piles; the second supporting main legs are connected to the first supporting main legs by the flange connection node.

[0013] According to the split-type jacket structure of an offshore wind turbine provided by the present invention, the flange connection node includes an upper flange and a lower flange, the upper flange is fixed to the bottom of the first supporting main leg, the lower flange is fixed to the top of the second supporting main leg, the upper flange and the lower flange are butted against each other, a plurality of first bolt holes are provided on the upper flange at equal intervals in the circumferential direction, a plurality of second bolt holes are provided on the lower flange, the first bolt holes and the second bolt holes are arranged coaxially corresponding to each other, a bolt is inserted into the first bolt hole, one end of the bolt passes through the second bolt hole and is threadedly connected with a nut.

[0014] According to the offshore wind turbine split jacket structure provided by the present invention, the bottom surface of the upper flange is configured as an arcuate convex surface, the top surface of the lower flange is configured as an arcuate concave surface, and the arcuate convex surface is adapted to the arcuate concave surface.

[0015] According to the offshore wind turbine split jacket structure provided by the present invention, the fixing assembly includes a plurality of stiffening ribs, which are respectively fixed between the upper flange and the first supporting main leg and between the lower flange and the second supporting main leg.

[0016] A method for installing a split-type jacket structure for an offshore wind turbine comprises the following steps:

[0017] Step 1: prefabrication in factory;

[0018] Complete the processing of the upper and lower jackets at the onshore processing plant, install the flange connection nodes on the upper and lower jackets respectively, and install fixing components between the flange connection nodes and the upper jacket, and between the lower jackets respectively:

[0019] The lower jacket is hoisted and tested with the upper jacket to verify that the overall structural angles are consistent with the design drawings. After the test is completed, the first bolt holes on the lower flange are enlarged to form second bolt holes, leaving room for adjustment for construction errors during the actual hoisting process.

[0020] Step 2: Install the jacket and steel pipe piles offshore;

[0021] Locate the designed position in the target sea area, and hoist the lower jacket to the seabed using a crane vessel. Insert steel pipe piles through the pre-set channel at the bottom of the lower jacket and drive them into the seabed to the designed depth using the pile-sinking process.

[0022] Step 3: hoisting and aligning the upper jacket offshore;

[0023] The transport ship transports the prefabricated upper jacket to the installation sea area; the crane ship hoists the upper jacket to the top of the lower jacket;

[0024] Step 4: tighten the flange connection node offshore;

[0025] Slowly lower the upper jacket until the convex arc surface at the bottom of the upper flange initially contacts the concave arc surface at the top of the lower flange. Then, under its own weight, the upper flange will automatically slide along the arc surface of the lower flange until it is completely in place. Then, fix the upper and lower jackets together using flange connection nodes and perform anti-corrosion treatment.

[0026] Step 5: Tower and fan installation;

[0027] The tower sections are installed on the pile platform at the top of the upper jacket, and finally the wind turbine unit is hoisted.

[0028] According to the installation method of the split jacket structure of an offshore wind turbine provided by the present invention, in step four, the flange connection node is tightened with increasing torque in three stages, and finally, sealant is injected and anti-corrosion treatment is performed.

[0029] The present invention discloses the following technical effects:

[0030] The connection part of the present invention adopts a continuous straight catheter main limb tube design, which avoids the cross-sectional mutation caused by geometric shape conversion in traditional solutions, effectively improves the structural stress state, and significantly enhances the load transfer efficiency and overall structural performance.

[0031] The connection method of the flange connection node of the present invention greatly reduces the technical difficulty of offshore construction, converts complex grouting operations into a standardized bolt connection process, and improves construction reliability and operational convenience.

[0032] Compared with grouting connection, the flange connection node of the present invention does not need to consider the maintenance period after grouting, thus shortening the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is an overall schematic diagram of the split-type jacket support structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the upper jacket and wind turbine tower of the present invention;

[0036] Figure 3 This is a schematic diagram of the lower jacket and steel pipe piles of the present invention;

[0037] Figure 4 This is a schematic diagram of the flange connection section of the present invention;

[0038] Figure 5 It is a schematic diagram of the upper flange of the present invention;

[0039] Figure 6 It is a schematic diagram of the lower flange of the present invention.

[0040] Among them, 1. Tower; 2. Upper conductor frame; 201. First supporting leg; 202. First diagonal brace; 3. Flange connection node; 301. Upper flange; 302. Lower flange; 303. Stiffening rib; 304. Bolt; 305. First bolt hole; 306. Second bolt hole; 4. Lower conductor frame; 401. Second supporting leg; 402. Horizontal brace; 403. Second diagonal brace; 5. Steel pipe pile. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Reference Figures 1-6 The present invention provides a split-type jacket structure for an offshore wind turbine, comprising:

[0044] A lower jacket frame 4, with a steel pipe pile 5 fixed at the bottom of the lower jacket frame 4;

[0045] An upper jacket 2, on the top of which a tower 1 is mounted, is mounted on the top of a lower jacket 4;

[0046] Flange connection nodes 3, the upper jacket 2 and the lower jacket 4 brackets are fixed together through a number of flange connection nodes 3;

[0047] The fixing components are respectively arranged between the flange connection node 3 and the upper jacket 2 and the lower jacket 4.

[0048] To further optimize the solution, the upper jacket 2 includes several first supporting main legs 201, adjacent first supporting main legs 201 are fixed by first diagonal braces 202, pile platforms are fixed on the top ends of the first supporting main legs 201, and the tower 1 is fixed on the top surface of the pile platforms.

[0049] The upper jacket 2 achieves structural load-bearing and deformation resistance through the synergistic effect of "main leg load-bearing + diagonal bracing for stability." Several first supporting main legs 201 serve as core load-bearing components, directly bearing the vertical loads (including the weight of the equipment and vertical wind loads) transmitted from the upper tower 1. The first diagonal braces 202 between adjacent first supporting main legs 201 utilize the principle of triangular stabilization to convert horizontal loads (such as wind loads and wave impact) into axial forces and transmit them to the main legs, reducing bending deformation and improving overall lateral stiffness. The top pile platform evenly distributes the tower 1 load to each first supporting main leg 201 by expanding the contact area, avoiding local stress concentration and ensuring the structural stability of the upper jacket 2 under complex loads.

[0050] To further optimize the solution, the lower conductor frame 4 includes several second supporting main legs 401, the first supporting main legs 201 and the second supporting main legs 401 are arranged in a one-to-one correspondence, and the adjacent second supporting main legs 401 are fixed by second diagonal braces 403 and horizontal braces 402, and the bottom of the second supporting main legs 401 is fixed on the steel pipe pile 5; the second supporting main legs 401 and the first supporting main legs 201 are connected by a flange connection node 3.

[0051] The lower conductor frame 4 serves as a transitional component connecting the upper structure and the foundation, achieving load transfer and overall stability through "layered force transmission + multi-dimensional constraints." Several second support main legs 401 correspond one-to-one with the first support main legs 201, forming a linear channel for vertical load transfer and preventing additional bending moments caused by load eccentricity. The second diagonal braces 403 (resisting diagonal forces) and horizontal braces 402 (resisting horizontal shear forces) between adjacent second support main legs 401 form a spatial grid structure, significantly improving the overall rigidity of the lower conductor frame 4 and effectively dispersing horizontal loads and torque. The bottom is fixed on the steel pipe piles 5, using the friction and adsorption between the steel pipe piles 5 and the foundation soil to provide vertical anchoring force and horizontal pull-out resistance, stably transferring all loads (vertical, horizontal, and bending moments) transmitted from the upper part to the foundation, ensuring the overall anti-overturning ability of the structure.

[0052] Further optimization scheme, the flange connection node 3 includes an upper flange 301 and a lower flange 302, the upper flange 301 is fixed to the bottom of the first supporting main leg 201, and the lower flange 302 is fixed to the top of the second supporting main leg 401, the upper flange 301 and the lower flange 302 are butt-jointed, and a plurality of first bolt holes 305 are circumferentially evenly spaced on the upper flange 301, and a plurality of first bolt holes 305 are initially opened on the lower flange 302, and then the second bolt holes 306 are obtained by expanding the first bolt holes 305, and the first bolt holes 305 are coaxially arranged one by one with the second bolt holes 306, a bolt 304 is inserted into the first bolt hole 305, and one end of the bolt 304 passes through the second bolt hole 306 and is threadedly connected with a nut.

[0053] Flange connection node 3 achieves a rigid connection and load transfer between the upper and lower jackets 4 through a combination of "bolt 304 preload + frictional force transmission." After the upper flange 301 and lower flange 302 are docked, bolts 304 are inserted through their corresponding bolt holes and tightened with nuts. The preload of bolts 304 creates normal pressure on the flange contact surfaces, which in turn transmits horizontal shear and torque through frictional force. Vertical loads are directly transmitted through the rigid contact of the flanges.

[0054] Bolt 304 is tightened in a "cross symmetrical" sequence and loaded three times, with each load increasing by 30% of the design torque value.

[0055] The flange is welded using a segmented symmetrical welding process, and the dimensions are reviewed every time 30% of the welds are completed to control welding deformation.

[0056] Redundant bolt 304 holes are configured in the flange design as a safety reserve, and axial force monitoring sensors are integrated in the key bolts 304. When the monitoring data shows that the pre-tightening force of some bolts 304 has decayed to the set threshold, the spare holes can be activated to implement bolt 304 replacement to maintain the long-term service performance of the connection structure.

[0057] To further optimize the solution, the bottom surface of the upper flange 301 is set as an arc-shaped convex surface, and the top surface of the lower flange 302 is set as an arc-shaped concave surface, and the arc-shaped convex surface is adapted to the arc-shaped concave surface. The purpose is to rely on the effect of its own weight, and the upper flange will automatically slide along the arc surface of the lower flange until it is completely fitted to the specified position.

[0058] The flange connection's fault tolerance and load-bearing capacity are enhanced through "adaptive deformation + stress dispersion." The curved convex surface of the upper flange 301 mates with the curved concave surface of the lower flange 302, forming a slightly rotatable contact interface. When loads (such as wind or waves) cause slight relative rotation or differential settlement between the upper and lower jackets 4, the curved surfaces adapt to deformation through rolling contact, avoiding the additional stress generated by the rigid connection. Furthermore, the curved contact surface increases the contact area, dispersing local pressure, reducing stress concentration at the flange edges, and improving the fatigue resistance of the connection.

[0059] According to a further optimized solution, the fixing assembly includes a plurality of stiffening ribs 303 , which are fixed between the upper flange 301 and the first supporting main leg 201 , and between the lower flange 302 and the second supporting main leg 401 .

[0060] Stiffeners 303 enhance the connection between the flange and the main leg through a combination of "rigidity enhancement and stress transfer." Fixed between the flange and the main leg, these ribs form a triangular reinforcement structure. This not only increases the local stiffness of the flange-to-leg connection, but also resists the bending moment generated when the flange transfers loads (preventing tearing at the weld between the flange and the main leg due to excessive torque). Furthermore, they evenly transfer the loads (shear and bending moment) borne by the flange to the main leg, reducing local stress concentration and ensuring that the overall load-bearing capacity of the connection node matches that of the main leg.

[0061] A method for installing a split-type jacket structure of an offshore wind turbine comprises the following steps:

[0062] Step 1: prefabrication in factory;

[0063] After the upper and lower jackets 2 and 4 are machined at the onshore processing plant, the flange connection nodes 3 are installed on the upper and lower jackets 2 and 4, respectively. Fixing components are then installed between the flange connection nodes 3 and the upper and lower jackets 2 and 4, respectively.

[0064] The lower jacket 4 is hoisted and tested with the upper jacket 2 to verify that the overall structural angles are consistent with the design drawings. After the test docking is completed, the first bolt holes 305 on the lower flange 302 are enlarged to form second bolt holes 306, leaving room for adjustment for construction errors during the actual hoisting process.

[0065] Step 2: Install the jacket 4 and steel pipe piles 5 offshore;

[0066] Locate the designed position in the target sea area, and hoist the lower jacket 4 to the seabed using a crane ship; penetrate the steel pipe piles 5 through the preset channel at the bottom of the lower jacket 4 and penetrate the seabed to the designed depth using the pile driving process;

[0067] Step 3: hoisting and aligning the upper jacket 2 offshore;

[0068] The transport ship transports the prefabricated upper jacket 2 to the installation sea area; the crane ship hoists the upper jacket 2 to the top of the lower jacket 4;

[0069] Step 4: tighten the flange connection node 3 offshore;

[0070] Slowly lower the upper jacket 2 until the convex arc surface at the bottom of the upper flange 301 makes initial contact with the concave arc surface at the top of the lower flange 302. Subsequently, under its own weight, the upper flange 301 automatically slides along the arc surface of the lower flange 302 until it is completely in place. The upper and lower jackets 2 and 4 are then fixed together using the flange connection nodes 3 and treated for corrosion.

[0071] Step 5: Install the tower 1 and the fan;

[0072] The tower 1 segment is installed on the pile platform at the top of the upper jacket 2, and finally the wind turbine unit is hoisted.

[0073] To further optimize the solution, in step four, the flange connection node 3 is tightened with increasing torque in three stages, and finally a sealant is injected and an anti-corrosion treatment is performed.

[0074] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0075] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A split-type jacket structure for an offshore wind turbine, characterized in that: include: A lower conductor frame (4), wherein a steel pipe pile (5) is fixed at the bottom of the lower conductor frame (4); An upper jacket (2), a tower (1) is installed on the top of the upper jacket (2), and the upper jacket (2) is installed on the top of the lower jacket (4); Flange connection nodes (3), the upper jacket (2) and the lower jacket (4) bracket are docked and fixed via a plurality of flange connection nodes (3); A fixing assembly is provided between the flange connection node (3) and the upper conductor frame (2) and the lower conductor frame (4).

2. The offshore wind turbine split jacket structure according to claim 1, characterized in that: The upper jacket (2) comprises a plurality of first supporting main legs (201), adjacent first supporting main legs (201) are fixed via first diagonal braces (202), a pile base is fixed at the top end of each first supporting main leg (201), and the tower (1) is fixed on the top surface of the pile base.

3. The offshore wind turbine split jacket structure according to claim 2, characterized in that: The lower conductor frame (4) includes a plurality of second supporting main legs (401), wherein the first supporting main legs (201) and the second supporting main legs (401) are arranged in a one-to-one correspondence, and adjacent second supporting main legs (401) are fixed by second diagonal braces (403) and horizontal braces (402), and the bottom of the second supporting main legs (401) is fixed on the steel pipe pile (5); the second supporting main legs (401) and the first supporting main legs (201) are connected by the flange connection node (3).

4. The offshore wind turbine split jacket structure according to claim 3, characterized in that: The flange connection node (3) includes an upper flange (301) and a lower flange (302), wherein the upper flange (301) is fixed to the bottom of the first supporting main leg (201), and the lower flange (302) is fixed to the top of the second supporting main leg (401), and the upper flange (301) and the lower flange (302) are butt-jointed, and a plurality of first bolt holes (305) are opened on the upper flange (301) at equal intervals in the circumferential direction, and a plurality of second bolt holes (306) are opened on the lower flange (302), and the first bolt holes (305) and the second bolt holes (306) are arranged coaxially one by one, and a bolt (304) is inserted into the first bolt hole (305), and one end of the bolt (304) passes through the second bolt hole (306) and is threadedly connected with a nut.

5. The offshore wind turbine split jacket structure according to claim 4, characterized in that: The bottom surface of the upper flange (301) is configured as an arcuate convex surface, and the top surface of the lower flange (302) is configured as an arcuate concave surface, and the arcuate convex surface is adapted to the arcuate concave surface.

6. The offshore wind turbine split jacket structure according to claim 4, characterized in that: The fixing assembly includes a plurality of stiffening ribs (303), and the stiffening ribs (303) are respectively fixed between the upper flange (301) and the first supporting main leg (201), and between the lower flange (302) and the second supporting main leg (401).

7. A method for installing a split jacket structure for an offshore wind turbine, based on the split jacket structure for an offshore wind turbine according to any one of claims 1 to 6, characterized in that: The steps include: Step 1: prefabrication in factory; The upper jacket (2) and the lower jacket (4) are processed in a land processing plant, the flange connection node (3) is installed on the upper jacket (2) and the lower jacket (4), and the fixing components are installed between the flange connection node (3) and the upper jacket (2) and between the lower jacket (4); The lower jacket (4) is hoisted and tested for docking with the upper jacket (2) to verify that the overall structural spatial angle is consistent with the design drawing; after the trial docking is completed, the first bolt hole (305) on the lower flange (302) is enlarged to form a second bolt hole (306) to reserve adjustment space for construction errors during the actual hoisting process; step two, the lower jacket (4) and the steel pipe pile (5) are installed offshore; Locating the designed position in the target sea area, hoisting the lower jacket (4) to the seabed by a crane ship; passing the steel pipe pile (5) through the preset channel at the bottom of the lower jacket (4), and penetrating the seabed to the designed depth by using a pile sinking process; Step 3, hoisting and aligning the upper jacket (2) offshore; The transport ship transports the prefabricated upper jacket (2) to the installation sea area; the crane ship hoists the upper jacket (2) to the top of the lower jacket (4); Step 4: tighten the flange connection node (3) offshore; The upper jacket (2) is slowly lowered so that the convex arc surface at the bottom of the upper flange (301) is initially in contact with the concave arc surface at the top of the lower flange (302); then, under the action of its own weight, the upper flange (301) automatically slides along the arc surface of the lower flange (302) until it is completely fitted into place; then, the upper jacket (2) and the lower jacket (4) are fixed through the flange connection node (3) and anti-corrosion treatment is performed; Step 5: Install the tower (1) and the fan; The tower (1) segments are installed on the pile platform at the top of the upper jacket (2), and finally the wind turbine unit is hoisted.

8. The method for installing a split-type jacket structure for an offshore wind turbine according to claim 7, characterized in that: In step 4, the flange connection node (3) is tightened in three stages with increasing torque, and finally a sealant is injected and an anti-corrosion treatment is performed.

Images