A polygonal tension leg platform foundation for wind power

Abstract

The application discloses a polygonal tension leg floating wind power platform foundation, and relates to the technical field of ocean engineering, which comprises at least five corner point pontoons, is connected through outer horizontal rod systems between adjacent corner point pontoons and forms a polygon, the center of the polygon is provided with a center column, the bottom of the center column is connected with each corner point pontoon through an inner horizontal rod system, the top of the center column is supported and fixed with a wind turbine tower base and is connected with each corner point pontoon through an inclined support rod system; the application adopts a plurality of corner point pontoons to form a pentagon and a polygon with more sides, provides self-floating stability for the platform by designing a plurality of small-size corner point pontoons, can comprehensively optimize the structural size of the connecting rod system, reduces the overall size of the platform, realizes the structural simplification, reduces the connecting nodes between the rod systems and reduces the fatigue risk while guaranteeing the overall performance and strength of the tension leg platform, has self-floating stability, can realize the overall integrated construction and overall towing installation of the wind turbine.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and more particularly, to a polygonal tension leg floating wind turbine platform foundation. Background Technology

[0002] Large-capacity floating wind turbine platform technology for deep-sea applications represents the future direction of offshore wind power development. Currently, floating wind turbine foundations generally adopt several forms, including barge-type, semi-submersible, tension leg (TLP) type, and monopole type (SPAR), floating on the water surface and providing foundation support for the floating wind turbine. TLP-type floating wind turbine platforms have advantages and prospects in large-scale deep-sea wind farm development due to their excellent motion performance, smaller mooring radius, and smaller sea area requirements. With the increasing size of deep-sea floating wind turbines, the weight of the turbines and their towers has significantly increased, and the center of gravity is higher, placing increasingly higher demands on the self-buoyancy and stability of the wind turbine foundation platform. Furthermore, with increasing water depth and harsher marine environments, the material and installation costs of the tension leg system in the TLP platform will account for a higher proportion of the overall project investment. How to simplify the design structure to reduce steel consumption while further optimizing the tension leg system design to save on material and installation costs is also one of the important issues that TLP-type floating wind turbine platforms need to address.

[0003] Existing TLP (Tension Pile Floating) wind turbine foundation platform concepts typically employ a triangular or quadrilateral truss structure. Self-buoyancy and stability are achieved through corner pontoons, facilitating the integrated construction and offshore transport of the wind turbine. The truss structure simplifies the structure by connecting and securing the pontoons to each other and to the turbine tower. The tension leg system is generally located at the base of the corner pontoons, connected to the seabed anchorage foundation. To ensure sufficient stability and safety even in the event of a single tension leg failure or maintenance, at least two tension legs should be installed at each corner to withstand harsh sea conditions and accommodate maintenance, replacement, and redundancy requirements. Therefore, for triangular or quadrilateral TLP platforms, at least six or eight tension legs are required; otherwise, due to the limitations of the bottom shape, failure of a single tension leg will cause the platform to capsize. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a tension leg floating wind power platform foundation in which multiple corner pontoons form a polygon with five or more sides.

[0005] To address the aforementioned technical problems, this invention provides a polygonal tension leg floating wind power platform foundation, connected to an underwater anchoring foundation. It includes at least five corner buoys, an outer horizontal strut system, a central column, an inner horizontal strut system, a diagonal bracing system, and a wind turbine tower base. Adjacent corner buoys are connected by the outer horizontal strut system to form a polygon. A central column is located at the center of the polygon. The bottom of the central column is connected to each corner buoy via the inner horizontal strut system, and the top of the central column is connected to each corner buoy via the diagonal bracing system. The top of the central column supports and fixes the wind turbine tower base.

[0006] According to a preferred embodiment of the present invention, each corner buoy is provided with a single tension tendon on its outer edge, and the tension tendon is connected to the anchoring foundation.

[0007] According to a preferred embodiment of the present invention, the interior of the corner buoy can be divided into a ballast tank or an empty tank.

[0008] According to a preferred embodiment of the present invention, the outer horizontal bar system and the inner horizontal bar system are located on the same horizontal plane.

[0009] According to a preferred embodiment of the present invention, the corner buoy is a closed structure with a horizontal cross-section of a circle or rectangle.

[0010] According to a preferred embodiment of the present invention, the central column is assembled from an integral cylindrical shape, an integral frustum shape, or a transitional section connecting a partial cylindrical shape and a partial frustum shape.

[0011] According to a preferred embodiment of the present invention, the wind turbine tower base is a cylindrical structure.

[0012] According to a preferred embodiment of the present invention, the outer horizontal rod system is a circular tube structure with a circular cross-section.

[0013] According to a preferred embodiment of the present invention, the inner horizontal rod system is a circular tube structure with a circular cross-section.

[0014] According to a preferred embodiment of the present invention, the diagonal bracing system is a circular tube structure with a circular cross-section.

[0015] The technical advantages of this invention are as follows: 1. This invention discloses a polygonal tension leg floating wind turbine platform foundation, comprising five or more corner pontoons. Adjacent corner pontoons are connected by an outer horizontal strut system. The center lines of the corner pontoons form a polygon. The corner pontoons are connected to a central column via an inner horizontal strut system to provide the main buoyancy and stability for the platform. The top of the central column supports the wind turbine tower base. Each corner pontoon is connected to the wind turbine tower base via a diagonal bracing system. The wind turbine tower base supports the wind turbine, thereby achieving the beneficial effect of designing a tension leg floating wind turbine platform foundation with multiple corner pontoons forming a polygon with five or more sides.

[0016] 2. The present invention provides a polygonal tension leg floating wind power platform foundation. By using five or more corner buoys, only one tension leg tendon can be set at each corner buoy. Even if any tendon is damaged or under maintenance, the remaining tendons still provide stable mooring for the platform, effectively reducing the number of tension leg tendons and lowering material and installation costs.

[0017] 3. This invention relates to a polygonal tension leg floating wind turbine platform foundation. The arrangement of multiple corner buoys effectively increases the buoyancy and stability of the platform. During the platform construction and transportation phase, the corner buoys can float on the water surface to provide sufficient self-buoyancy stability for the platform, enabling the overall integration and towing transportation of large wind turbines and reducing project investment. After the platform is installed and positioned at sea, the corner buoys are submerged in water, reducing the amount of structural steel and wave loads, while the tension leg system provides stability for the platform.

[0018] 4. The present invention provides a polygonal tension leg floating wind power platform foundation, which adopts a central column design, which can increase the drainage volume and provide greater buoyancy to support the wind turbine load, and optimize the corner float size; the continuous column structure is also more conducive to the transmission of wind turbine load.

[0019] 5. This invention discloses a polygonal tension leg floating wind turbine platform foundation. The outer horizontal strut system, inner horizontal strut system, and diagonal bracing system have sufficient dimensions, eliminating the need for inter-strut strut structures. This ensures strength while reducing the design of joints between struts, lowering the risk of joint fatigue, and improving construction efficiency. Simultaneously, the larger strut structure can also provide some buoyancy, thus allowing for comprehensive optimization of the dimensions of the corner pontoons and the central column.

[0020] 6. The present invention provides a polygonal tension leg floating wind power platform foundation, which adopts multiple corner point pontoons. Compared with triangular or quadrilateral TLP platforms, it has better stability characteristics. It can further optimize the size and spacing of the pontoons, reduce the size of the connecting rod system, and simplify the structure. It is particularly suitable for large offshore wind turbines with high requirements for self-buoyancy stability. Attached Figure Description

[0021] Figure 1 This is a perspective view of a polygonal tension leg floating wind power platform foundation according to the present invention; Figure 2 This is a front view of a polygonal tension leg floating wind power platform foundation according to the present invention; Figure 3 This is a top view of a polygonal tension leg floating wind power platform foundation according to the present invention; Figure 4 This is one of the structural schematic diagrams of the central column of the foundation of a polygonal tension leg floating wind power platform according to the present invention; Figure 5 This is the second schematic diagram of the structure of the central column of the foundation of a polygonal tension leg floating wind power platform according to the present invention; Figure 6 This is the third schematic diagram of the structure of the central column of the foundation of a polygonal tension leg floating wind power platform according to the present invention; Figure 7 This is the fourth structural schematic diagram of the central column of the foundation of a polygonal tension leg floating wind power platform according to the present invention.

[0022] Reference numerals: 1-Corner buoy; 2-Central column; 3-Outer horizontal strut system; 4-Inner horizontal strut system; 5-Diagonal bracing system; 6-Tension leg system; 7-Wind turbine tower base; 8-Wind turbine tower; 9-Wind turbine; 10-Anchoring foundation; 21-Top frustum transition section; 22-Bottom cylinder; 23-Bottom frustum transition section; 24-Bottom buoy. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the invention.

[0024] like Figures 1 to 7 As shown, a polygonal tension leg floating wind turbine platform foundation, connected to an underwater anchoring foundation 10, includes at least five corner pontoons 1, an outer horizontal strut system 3, a central column 2, an inner horizontal strut system 4, a diagonal bracing system 8, and a wind turbine tower base 7. Adjacent corner pontoons 1 are connected by the outer horizontal strut system 3 to form a polygon. A central column 2 is located at the center of the polygon. The bottom of the central column 2 is connected to each corner pontoon 1 through the inner horizontal strut system 4. The top of the central column 2 is connected to each corner pontoon 1 through the diagonal bracing system 8. The wind turbine tower base 7 is fixedly supported on the top of the central column 2.

[0025] like Figures 1 to 3As shown, a tension leg type floating wind turbine platform foundation comprises seven main parts: five or more corner pontoons 1, a central column 2, a wind turbine tower base 7, outer horizontal struts 3, inner horizontal struts 4, diagonal bracing 5, and a tension leg system 6. The center lines of the corner pontoons 1 form a polygon, which, together with the central column 2, provides the main buoyancy and stability for the platform. The top of the central column 2 connects to the wind turbine tower base 7. The outer horizontal struts 3, inner horizontal struts 4, and diagonal bracing 5 connect the corner pontoons 1 and the central column 2, ensuring platform strength and providing partial buoyancy. Each corner pontoon 1 has a tension tendon forming the tension leg system 6 on its outer edge, with its lower end connected to the seabed anchoring foundation 10, providing downward pretension to fix the platform and achieving redundancy.

[0026] Five corner buoys 1 are used, located at the edge corners of the bottom of the platform. The five corner buoys 1 are connected by an outer horizontal rod system 3. The corner buoys 1 are closed structures with a horizontal cross-section of circular or rectangular. They are adjacent to the external seawater and can be divided into ballast tanks or empty tanks. There are five or more corner buoys 1, and their center lines form a polygon.

[0027] The central column 2 is located in the center of the platform. Its bottom is connected to the corner float 1 through the inner horizontal rod system 4, and its top supports the wind turbine tower base 7. Depending on the size of the wind turbine tower base 7, the central column 2 can be an integral cylindrical shape, an integral frustum shape, or assembled by connecting and assembling a partial cylindrical shape and a partial frustum shape transition section.

[0028] Among them, the wind turbine tower base 7 is a cylindrical structure, with the upper part connected to the wind turbine tower 8 and the bottom part connected to the central column 2.

[0029] The outer horizontal strut system 3 is a circular tube structure with a circular cross-section, used for connecting the corner pontoons 1. The inner horizontal strut system 4 is a circular tube structure with a circular cross-section, used for connecting the corner pontoons 1 to the bottom of the central column 2. The diagonal bracing system 5 is a circular tube structure with a circular cross-section, used for connecting the corner pontoons 1 to the top of the central column 2. It has sufficient dimensions to ensure structural strength and does not require connecting struts between each other.

[0030] Among them, the tension leg system 6 uses the same number of tension tendons as the corner buoys 1. Each corner buoy 1 is equipped with a tension tendon at its outer edge, and its upper end is connected to the outer edge of the corner buoy 1 and connected to the bottom anchoring foundation 10.

[0031] like Figure 4 As shown, the central column 2 is an integral cylindrical shape, and its top dimensions match those of the wind turbine tower base 7.

[0032] like Figure 5As shown, the central column 2 is an integral frustum shape, and its top dimensions match those of the wind turbine tower base 7.

[0033] like Figure 6 As shown, the central column 2 is assembled by connecting the bottom cylindrical body 22 and the top frustum-shaped transition section 21, and the top dimension of the central column 2 matches the wind turbine tower base 7.

[0034] like Figure 7 As shown, the central column 2 is assembled by sequentially connecting the bottom float 24, the bottom frustum transition section 23, the bottom cylinder 22, and the top frustum transition section 21. The top dimensions of the central column 2 match those of the wind turbine tower base 7.

[0035] The tension leg floating wind turbine platform foundation involved in this invention is mainly applicable to horizontal or vertical axis wind turbines 9 with towers. Because this invention uses five corner buoys 1 at the bottom edge corners of the platform, only one tension leg tendon can be installed at each corner buoy 1. Even if any tendon is damaged or under maintenance, the remaining tendons still provide stable mooring for the platform, effectively reducing the number of tension leg tendons, lowering material and installation costs, and offering significant advantages in deep water areas. Simultaneously, the five corner buoys 1 effectively increase the platform's self-buoyancy and stability, adapting to larger wind turbines 9. Furthermore, the dimensions and spacing of the corner buoys 1 can be comprehensively optimized, reducing the size of the connecting rod system. During the construction and transportation phases, the corner buoys 1 float on the water surface, providing sufficient self-buoyancy and stability for the platform, enabling the integrated construction and towing transportation of the wind turbine 9 as a whole, reducing the risks and engineering investment associated with installing the wind turbine 9 at sea. Furthermore, the central column 2 design increases the drainage volume and provides greater buoyancy to support the load of the upper wind turbine 9, while also optimizing and reducing the size of the corner floats 1. The continuous central column 2 structure also facilitates the transfer of wind turbine loads. The outer horizontal strut system 3, the inner horizontal strut system 4, and the diagonal bracing system 5 have sufficient dimensions, eliminating the need for inter-strut bracing structures. This ensures strength while reducing the number of joints between struts, lowering the risk of joint fatigue, and improving construction efficiency.

[0036] This platform utilizes multiple corner buoys 1 to form a polygon with five or more sides at its bottom. The upper wind turbine tower 8 is supported by a central column 2 and a simple connecting support structure. A single tension rib is installed at each corner buoy 1 and connected to the seabed anchoring foundation 10. By designing multiple small-sized corner buoys 1, the platform provides self-buoyancy and stability. This optimizes the structural dimensions of the connecting rod system, reducing the overall size of the platform. While ensuring the overall performance and strength of the tension leg platform, it simplifies the structure, reduces the number of connection nodes between rods, and lowers fatigue risk. It possesses self-buoyancy and stability, enabling the integrated construction and towing installation of the wind turbine 9. Furthermore, by installing single tension ribs at the polygonal corners, the total number of tension ribs is effectively reduced, ensuring the platform maintains a certain degree of stability even if any rib is damaged or under maintenance. This effectively reduces the material cost of the tension leg and the cost of offshore installation, making it suitable for large deep-water floating wind turbines.

[0037] This platform employs a tension leg mooring system. After installation at sea, the corner buoy 1 lies below the water surface, with only the diagonal bracing system 5 and the central column 2 passing through the water. This effectively reduces wave loads. The buoyancy provided by the underwater floating body and the tension provided by the tension leg system 6 ensure the platform remains stable and has good motion performance, providing a stable foundation for the upper wind turbine 9 and improving its power generation efficiency. Furthermore, compared to platforms using traditional extended mooring systems, this invention has a smaller mooring radius, reducing sea area requirements and making it more suitable for large-scale floating wind farm development.

[0038] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A polygonal tension leg floating wind turbine platform foundation, connected to an underwater anchor foundation, comprising at least five corner buoys, an outer horizontal strut system, a central column, an inner horizontal strut system, a diagonal bracing system, and a wind turbine tower base, characterized in that... Adjacent corner pontoons are connected by an outer horizontal strut system to form a closed polygonal structure. A central column is located at the center of the polygon. The bottom of the central column is connected to each corner pontoon by an inner horizontal strut system, and the top of the central column is connected to each corner pontoon by a diagonal bracing system. The top of the central column supports and fixes the wind turbine tower base. Each corner pontoon has a single tension rib on its outer edge, which is connected to the anchoring foundation. The interior of each corner pontoon is divided into ballast tanks or empty tanks, and the corner pontoons are evenly distributed around the central column. The outer and inner horizontal strut systems are located on the same horizontal plane.

2. The polygonal tension leg floating wind turbine platform foundation according to claim 1, characterized in that, The corner pontoon is a closed structure with a horizontal cross-section that is circular or rectangular.

3. The polygonal tension leg floating wind turbine platform foundation according to claim 1, characterized in that, The central column is assembled from an integral cylindrical shape, an integral frustum shape, or a transitional section connecting a partial cylindrical shape and a partial frustum shape.

4. The polygonal tension leg floating wind turbine platform foundation according to claim 1, characterized in that, The wind turbine tower base is a cylindrical structure.

5. The polygonal tension leg floating wind turbine platform foundation according to claim 1, characterized in that, The outer horizontal rod system is a circular tube structure with a circular cross-section.

6. The polygonal tension leg floating wind turbine platform foundation according to claim 1, characterized in that, The inner horizontal rod system is a circular tube structure with a circular cross-section.

7. The polygonal tension leg floating wind turbine platform foundation according to claim 1, characterized in that, The diagonal bracing system is a circular tube structure with a circular cross-section.

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