A three-legged lattice wind turbine tower and method of manufacturing the same

Abstract

This invention belongs to the field of wind turbine tower technology and discloses a three-limb lattice wind turbine tower and its manufacturing method. The device includes several three-limb columns arranged circumferentially; two adjacent three-limb columns in the horizontal direction are fixedly connected by a horizontal ring truss; two adjacent three-limb columns in the vertical direction are fixedly connected by diagonal bracing; each three-limb column includes a support column and a tie rod, and two adjacent supports are fixedly connected by the tie rod; the support column is formed by welding several steel plates axially into a polygonal cross-section column, and the interior of the polygonal cross-section column is filled with concrete; the horizontal ring truss fixes adjacent three-limb columns on the same floor, constrains the three-limb columns circumferentially, and disperses horizontal wind loads; the diagonal bracing is used to connect the three-limb columns of the upper and lower floors, transmit and dissipate the inter-story shear force, vertical load and wind vibration alternating load of the tower, constrain the relative slippage, misalignment and torsional deformation of the tower body between floors, improve the overall vertical stiffness, torsional performance and overall structural stability of the tower, and extend the service life of the tower.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine tower technology, and relates to a three-limb lattice wind turbine tower and its manufacturing method. Background Technology

[0002] To improve wind energy utilization efficiency in low-wind-speed areas, existing wind power optimization technologies generally increase the installation height of wind turbine towers to obtain stable high-altitude wind energy and increase blade diameter to improve swept efficiency. Increased tower height intensifies the dynamic response of the structure, affecting the tower's structural strength, overall stability, bending stiffness, and fatigue durability. Simultaneously, large-diameter towers are constrained by land transportation limitations and the availability of large hoisting equipment, increasing transportation costs and on-site installation difficulties.

[0003] Existing wind turbine tower support structures include steel towers and precast prestressed steel-concrete hybrid towers. As the tower height increases, the structural flexibility of the steel tower increases, requiring larger cross-sectional dimensions and thicker steel plates to compensate for structural stiffness. Steel-concrete hybrid towers are limited by the physical and chemical properties of the concrete substrate, the connection structure of segmented components, and the single prestressed load-bearing system. During long-term service, they are prone to problems such as local stress concentration in the tower wall, concrete cracking, prestressing tendon stress relaxation, and aging failure of joint connection components. These problems lead to structural reliability degradation issues such as tower load-bearing capacity reduction, abnormal deformation, and excessive vibration, making it difficult to meet the long-term safe operation requirements of ultra-high and high-load wind turbines. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a three-limb lattice wind turbine tower and its manufacturing method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a three-limb lattice wind turbine tower, comprising a plurality of three-limb columns arranged circumferentially; two adjacent three-limb columns in the horizontal direction are fixedly connected by a horizontal ring truss; two adjacent three-limb columns in the vertical direction are fixedly connected by diagonal bracing; each three-limb column includes a support column and a connecting member, and two adjacent support columns are fixedly connected by the connecting member; each support column is formed by welding a plurality of steel plates axially into a polygonal cross-section column, and the interior of the polygonal cross-section column is filled with concrete.

[0006] Furthermore, the support column is assembled from several segments along the vertical direction, and adjacent upper and lower segments are fixedly connected by connectors.

[0007] Furthermore, the diagonal braces are arranged in a crisscross pattern, with each end of the diagonal brace connected to the node of two adjacent three-limb columns in the vertical direction.

[0008] Furthermore, the cross-section of the wind turbine tower gradually decreases with increasing height; the cross-section of the wind turbine tower is polygonal.

[0009] Furthermore, the height of a single segment of the support column is 10. 20m.

[0010] Furthermore, the three columns are arranged in a polygonal shape with the central axis of the tower as the center.

[0011] Furthermore, the included angles between two adjacent three-limb columns with the central axis of the tower as the center are equal.

[0012] Furthermore, the steel plate is a U-shaped steel plate.

[0013] Furthermore, the connecting component is a flange.

[0014] This invention also provides a method for manufacturing a three-limb lattice wind turbine tower. Based on the above-mentioned three-limb lattice wind turbine tower, the method includes the following steps: welding the steel plates axially into polygonal cross-section columns, pouring concrete inside the polygonal cross-section columns to obtain support columns; connecting several support columns with tie rods to obtain three-limb columns; arranging several three-limb columns at equal angular intervals in the circumferential direction and fixing them together with horizontal ring trusses to obtain a first-layer lattice wind turbine tower; fixing adjacent first-layer lattice wind turbine towers and second-layer lattice wind turbine towers together with diagonal braces, and repeating the above steps to obtain a three-limb lattice wind turbine tower.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This invention discloses a three-limb lattice-structure wind turbine tower. The three limbs are arranged in a ring, and the horizontal ring truss and diagonal bracing overcome the shortcomings of traditional wind turbine tower structures, such as single force distribution and poor stability. The horizontal ring truss fixes and connects adjacent three-limbs on the same floor, constraining the three limbs in a ring, distributing horizontal wind loads, and avoiding lateral displacement, outward deformation, and stress concentration caused by independent force on a single three-limb. This improves the single-layer planar stiffness and horizontal lateral displacement resistance of the tower. The diagonal bracing connects the three limbs of the upper and lower floors, transferring and dissipating inter-story shear forces, vertical loads, and alternating wind loads. It also constrains relative slippage, misalignment, and torsional deformation between tower floors, improving the overall vertical stiffness, torsional performance, and overall structural stability of the tower, and extending the service life of the tower. The three limbs include supports and tie rods. The tie rods constrain the relative positions of the supports, ensuring that each support is stressed as a whole, avoiding damage caused by single support bearing pressure or bending overload, and reducing overall structural failures caused by single-limb failure.

[0016] The support column is formed by welding several steel plates along the axial direction into a polygonal cross-section column. The outer steel plate bears the tensile and shear forces of the structure, while the inner concrete bears the vertical pressure. The two materials complement each other, which not only inhibits the bulging and instability deformation of the steel plate under pressure, but also improves the overall load-bearing strength and buckling resistance of the support column. Compared with traditional all-steel towers, it reduces the amount of steel used, lightens the structural self-weight, reduces manufacturing costs, reduces the overall windward area of ​​the tower, weakens the impact of wind load on the tower, and improves the adaptability and operational safety of the wind turbine tower under complex wind conditions. At the same time, compared with traditional large-section solid steel tube concrete columns, the three-limb column not only reduces the structural self-weight, but also avoids the problem of excessive transportation and hoisting weight.

[0017] The support column is assembled from several segments along the vertical direction. Adjacent upper and lower segments are fixedly connected by connectors. This solves the technical problems of limited transportation, difficult hoisting, and inconvenient construction of integral ultra-long tower components. By breaking down the ultra-long support column into multiple standardized independent segments, it can adapt to the size and weight limits of conventional land transportation, avoiding the problems of exceeding size limits, difficult transfer, and high transportation costs associated with transporting integral ultra-long components, thus improving the convenience and versatility of transfer. During on-site construction, the upper and lower segments are fixedly connected by connectors, eliminating the need for extensive high-altitude welding operations, reducing the amount of hot work at height, lowering the safety risks of high-altitude construction, shortening the on-site construction assembly cycle, and improving the overall construction efficiency of the tower.

[0018] The diagonal bracing is arranged in a cross pattern, with each end of the diagonal bracing connected to the node positions of the adjacent three columns in the vertical direction. This solves the problems of insufficient inter-story stiffness, weak lateral displacement resistance, and large wind-induced sway in traditional towers. The cross-arranged diagonal bracing can bear, disperse, and transfer the vertical inter-story shear force, vertical self-weight load, and horizontal alternating load generated by wind vibration, so that various loads between stories are evenly distributed. By utilizing the positioning advantages of the nodes at both ends of the diagonal bracing, the relative positions between the upper and lower three columns can be constrained, limiting relative slippage, misalignment, and torsional deformation of the tower body between stories.

[0019] The three columns are arranged in a polygonal pattern with the tower's central axis as the center, resulting in a centrally symmetrical spatial layout of the overall tower force distribution. This optimizes the load distribution and overall mechanical performance of the wind turbine tower. The circumferential arrangement evenly distributes the tower's self-weight, the concentrated load of the wind turbine equipment, and the external wind load along the circumferential direction of the tower to each of the three columns, avoiding the problems of localized concentrated and uneven stress in traditional towers. The symmetrical arrangement around the central circumference ensures consistent stiffness in all horizontal directions, improving the tower's wind resistance, overturning resistance, and torsional resistance. This allows the tower to adapt to wind loads from any direction, enhancing the adaptability and operational stability of the high-tower structure under complex wind field conditions.

[0020] The cross-section of the wind turbine tower is polygonal, and the outer contour dimension decreases from bottom to top with the erection height, forming an overall shape that is wider at the bottom and narrower at the top. The bottom of the tower needs to bear the weight of the entire tower, and the upper part needs to bear the wind turbine nacelle and blade equipment, ensuring the vertical pressure bearing stability and anti-overturning ability at the bottom. The cross-sectional dimensions of the tower gradually narrow upward, reducing the windward area of ​​the upper tower body and reducing the overturning moment generated by strong winds at high altitudes. Attached Figure Description

[0021] Figure 1 This is a structural schematic diagram of a three-limb lattice wind turbine tower according to the present invention; Figure 2 This is a top view of a three-limb lattice wind turbine tower according to the present invention; Figure 3 This is a schematic diagram of the three-limb column structure in an embodiment of the present invention; Figure 4 This is a schematic diagram of the support structure in an embodiment of the present invention.

[0022] Figure label: 2-Three-limb column; 3-Column; 4-Fitting material; 5-Steel plate; 6-Concrete; 7-Diagonal brace; 8-Horizontal ring truss. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] Example 1 This invention discloses a three-limb lattice-type wind turbine tower, comprising a plurality of three-limb columns 2 arranged circumferentially; two adjacent three-limb columns 2 in the horizontal direction are fixedly connected by a horizontal ring truss 8; two adjacent three-limb columns 2 in the vertical direction are fixedly connected by diagonal braces 7; each three-limb column 2 includes a support column 3 and a connecting member 4, with two adjacent support columns 3 fixedly connected by the connecting member 4; each support column 3 is formed by welding a plurality of steel plates 5 axially into a polygonal cross-section column, and the interior of the polygonal cross-section column is filled with concrete 6, such as... Figure 4 As shown.

[0025] Specifically, the three-limb lattice wind turbine tower includes three-limb columns 2, a horizontal ring truss 8, and diagonal braces 7. The three-limb columns 2 are composed of support columns 3 and connecting members 4. The support columns are composed of steel plates 5 and concrete 6. The steel plates 5 are U-shaped steel plates. Adjacent three-limb columns 2 in the horizontal direction are fixedly connected by the horizontal ring truss 8. Figure 2As shown, the vertically arranged three-limb columns 2 are diagonally connected and limited by the diagonal bracing 7. The three-limb columns 2 are composed of support columns 3 and connecting materials 4. Adjacent support columns 3 are connected by connecting materials 4. The support column 3 is formed by welding multiple steel plates 5 along the axial direction to form a hollow polygonal cross-section column. The hollow polygonal cross-section column is filled with cast-in-place dense concrete 6. In this embodiment, there are 12 three-limb columns 2. Every 4 three-limb columns 2 are arranged on the same horizontal installation surface and are arranged in layers from top to bottom. The three-limb columns 2 of each layer are connected in the same layer in the circumferential direction by the horizontal ring truss 8 and the vertical inter-layer limiting constraint is achieved by the diagonal bracing 7 to improve the overall stability of the tower.

[0026] The 12 three-limb columns 2 are evenly arranged around the vertical central axis of the tower. The included angle between two adjacent three-limb columns 2 with the central axis of the tower as the center is equal in the same horizontal plane. The equal included angle can evenly distribute the self-weight load of the tower, the instantaneous storm load, the annual pulsating wind load, and the alternating load of the wind turbine start-up and shutdown along the circumference to each support column 3. From the layout, the defects of concentrated overload of single-point components are eliminated, and structural hazards such as buckling under pressure and lateral deformation of local components are avoided. The overall torsional resistance and long-term service stability of the tower are optimized. Compared with conventional single-tube steel towers, the stress is more balanced, and the anti-overturning and anti-wind vibration capabilities are improved.

[0027] The three-limb column 2 is composed of the vertical load-bearing support column 3 and the horizontal connecting component lacing 4, such as Figure 3 As shown, the three-limb column 2 consists of three parallel support columns 3. A connecting member 4 is installed between adjacent support columns 3 along the height direction, connecting the three independent support columns 3 into a whole. The connecting member 4 serves two purposes: firstly, it constrains the relative spatial position of the three support columns 3, limiting independent displacement, lateral bending, and overall torsional deformation of a single support column 3 under long-term self-weight pressure, reciprocating lateral wind loads, and dynamic loads from wind turbine operation, thus avoiding stress exceeding limits and localized damage caused by a single support column 3 bearing pressure and bending alone; secondly, the connecting member 4 and the support columns 3 form a hollow structure, reducing the overall windward projection area of ​​the three-limb column 2, lowering the additional wind load generated by lateral airflow impact, and reducing the horizontal thrust on the tower body under high wind conditions, thus solving the technical problems of large windward area and significant wind-induced vibration in traditional solid towers.

[0028] The support column 3 is composed of steel plates 5 and concrete 6. The support column 3 is formed by welding the steel plates 5 together end to end along the axial direction to form a polygonal cross-section column, and then filling it with concrete 6. After solidification, it forms a support column 3 with steel plates 5 on the outside and concrete 6 on the inside. The steel plates 5 mainly bear the tensile stress, bending moment, and local concentrated shear load generated by the structural operation. The cylindrical body formed by the steel plates 5 can also directly serve as a formwork for concrete pouring, simplifying the prefabrication process. The concrete 6 filling the cavity formed by the steel plates 5 restrains the steel plates 5 from outward bulging, radial deformation, and overall compressive instability under compression conditions, thereby improving the vertical bearing capacity and buckling resistance of the support column 3.

[0029] The support column 3 is assembled from several segments along its height. Adjacent upper and lower segments are fixedly connected by connectors. In this embodiment, the support column 3 is prefabricated in segments. The support column 3 is divided into multiple segments along its vertical height. Adjacent upper and lower segments are connected by flanges on the construction site. The height of a single segment is 10m to 20m. The ultra-long support column 3 is divided into standardized short sections, which solves the problem of excessive transportation and high transportation costs of large-size ultra-long tower components over long distances. The segmented single components can be adapted to the rated lifting load of conventional lifting equipment at wind power construction sites, reducing the difficulty of high-altitude lifting operations and construction safety risks. The upper and lower segments are connected by flanges, which can reduce the amount of high-altitude hot work welding compared with existing high-altitude welding construction and shorten the overall construction period. On the same horizontal plane, two adjacent three-limb columns 2 are connected by a horizontal ring truss 8. The horizontal ring truss 8 forms a circumferential constraint on the three-limb columns 2 on the same floor, which restricts the outward expansion and lateral bending deformation of each three-limb column 2 under the action of sudden horizontal wind load, improves the overall planar stiffness and structural integrity of the single-layer tower, and quickly disperses the instantaneous horizontal load under strong wind weather, preventing local deformation and stress concentration of a single three-limb column 2 under wind load.

[0030] The three-limb columns 2 of two adjacent upper and lower floors are connected by cross-arranged diagonal braces 7, such as... Figure 1 As shown, the cross-bracing 7 can bear and transfer the inter-layer shear force, vertical self-weight load, and reciprocating alternating load caused by wind vibration layer by layer downwards. From a structural constraint perspective, it limits the relative slippage, planar misalignment, and overall torsional deformation of the upper and lower towers, improves the overall vertical stiffness and lateral displacement resistance of the tower, and delays the corrosion aging and fatigue cracking rate of the steel structure. The wind turbine tower has a polygonal cross-section, and the outer contour dimensions gradually and uniformly decrease from bottom to top with the erection height, forming an overall structure that is wider at the bottom and narrower at the top. The bottom of the tower needs to bear the entire self-weight of the tower and all the concentrated loads of the upper wind turbine nacelle and blade equipment, ensuring the vertical bearing stability and anti-overturning capacity of the bottom. The cross-sectional dimensions of the tower gradually narrow upwards, reducing the windward area of ​​the upper tower and reducing the overturning moment generated by strong winds at high altitudes.

[0031] Steel plates 5 are welded together along the axial direction to form polygonal cross-section columns. Concrete 6 is poured into these polygonal cross-section columns, and after curing, support columns 3 are formed. Adjacent support columns 3 are segmented and fixed with connecting members 4 at predetermined intervals. Three support columns 3, connected by connecting members 4, form three-limb columns 2. A horizontal ring truss 8 is erected between adjacent three-limb columns 2 on the same horizontal plane and securely connected, forming the first layer of the lattice-type wind turbine tower. The tower is then erected layer by layer from bottom to top, with adjacent upper and lower layers of lattice-type wind turbine towers fixed by cross braces 7, and assembled layer by layer to the predetermined design elevation. A wind turbine generator set is installed at the top of the tower, capturing wind energy through the rotation of the generator's impeller and converting mechanical energy into electrical energy.

[0032] Steel plate 5 is a U-shaped steel plate, which allows the joints of adjacent steel plates 5 to fit tightly, improving the overall structural integrity and welding quality of column 3. The enclosure of steel plates 5 can be adapted to standardized prefabrication production, improve the forming stability of steel-concrete composite columns, and adapt to the long-term complex stress conditions of wind turbine towers.

[0033] When external natural wind acts laterally on the outer surface of the tower to generate horizontal loads, the horizontal forces generated at the same elevation are evenly distributed along the circumferential direction by the horizontal ring truss 8, avoiding structural hazards caused by concentrated loads in local areas. The shear forces and structural deformation trends generated between floors are constrained and transferred layer by layer by the cross bracing 7. The lacing 4 set inside the three columns 2 constrains the three columns 3 to maintain a synchronous and coordinated stress state. The outer steel plate 5 is specially designed to bear various tensile loads, and the internal densely cast concrete 6 bears all vertical compressive loads, maximizing the overall bearing capacity, wind resistance and structural durability.

[0034] Example 2 This invention discloses a manufacturing method for a three-limb lattice wind turbine tower. Based on the aforementioned three-limb lattice wind turbine tower, the method includes the following steps: welding the steel plate 5 axially into a polygonal cross-section column, pouring concrete 6 inside the polygonal cross-section column to obtain a support column 3; connecting several support columns 3 with connecting braces 4 to obtain three-limb columns 2; arranging several three-limb columns 2 at equal angular intervals in the circumferential direction and fixing them together with a horizontal ring truss 8 to obtain a first-layer lattice wind turbine tower; fixing adjacent first-layer lattice wind turbine towers and second-layer lattice wind turbine towers together with diagonal braces 7, and repeating the above steps to obtain a three-limb lattice wind turbine tower.

[0035] Specifically, firstly, multiple U-shaped steel plates 5 are taken and aligned axially. The joints of the steel plates 5 are sealed by welding, forming a polygonal cross-section column. Concrete 6 is poured into the internal cavity of the polygonal cross-section column. After the concrete 6 solidifies, the support column 3 is obtained. Connecting members 4 are installed between two adjacent support columns 3. Through the tie and constraint of the connecting members 4, the separate support columns 3 are assembled into three-limb columns 2. The three three-limb columns 2 are set at equal angular intervals in the circumferential direction with the central axis of the tower as the reference. On the same horizontal plane, two adjacent sets of three-limb columns 2 are connected by a horizontal ring truss 8 to obtain the first layer of lattice-type wind turbine tower. After the first layer of the lattice-type wind turbine tower is assembled, the second layer of the lattice-type wind turbine tower is obtained by prefabricating the support columns 3, assembling the three-limb columns 2, and assembling the single-layer tower. The second layer of the lattice-type wind turbine tower is then neatly erected directly above the first layer of the lattice-type wind turbine tower. Diagonal braces 7 are then installed between the two adjacent layers of the lattice-type wind turbine tower to secure them. The third layer of the lattice-type wind turbine tower is then obtained by prefabricating the support columns 3, assembling the three-limb columns 2, and assembling the single-layer tower. The third layer of the lattice-type wind turbine tower is then neatly erected directly above the second layer of the lattice-type wind turbine tower, resulting in a three-limb lattice-type wind turbine tower. The number of layers in the lattice-type wind turbine tower is determined by the actual height; in this embodiment, it is three layers.

[0036] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

Claims

1. A three-limb lattice-type wind turbine tower, characterized in that: Including several three-limbed columns arranged in a circumferential direction (2); Two adjacent three-limb columns (2) in the horizontal direction are fixedly connected by a horizontal ring truss (8); Two adjacent three-limb columns (2) in the vertical direction are fixedly connected by diagonal braces (7); The three-limb column (2) includes a support column (3) and a lacing material (4), and two adjacent supports column (3) are fixedly connected by the lacing material (4); The support column (3) is formed by welding several steel plates (5) axially into a polygonal cross-section column, and the interior of the polygonal cross-section column is filled with concrete (6).

2. The three-limb lattice wind turbine tower according to claim 1, characterized in that: The support column (3) is assembled from several segments along the vertical direction, and adjacent upper and lower segments are fixedly connected by connectors.

3. The three-limb lattice wind turbine tower according to claim 2, characterized in that: The diagonal braces (7) are arranged in a cross shape, and the two ends of the diagonal braces (7) are respectively connected to the nodes of two adjacent three-limb columns (2) in the vertical direction.

4. The three-limb lattice wind turbine tower according to claim 1, characterized in that: The cross-section of the wind turbine tower gradually decreases as the height increases; The cross-section of the wind turbine tower is polygonal.

5. The three-limb lattice wind turbine tower according to claim 2, characterized in that: The individual segment height of the support column (3) is 10. 20m.

6. The three-limb lattice wind turbine tower according to claim 1, characterized in that: The three columns (2) are arranged in a polygon with the central axis of the tower as the center.

7. The three-limb lattice wind turbine tower according to claim 6, characterized in that: The included angles between two adjacent three-limb columns (2) with the central axis of the tower as the center are equal.

8. The three-limb lattice wind turbine tower according to claim 1, characterized in that: The steel plate (5) is a U-shaped steel plate.

9. The three-limb lattice wind turbine tower according to claim 8, characterized in that: The connecting component is a flange.

10. A method for manufacturing a three-limb lattice-type wind turbine tower, characterized in that, Based on the three-limb lattice wind turbine tower according to any one of claims 1-9, the following steps are included: The steel plate (5) is welded along the axial direction into a polygonal cross-section column, and concrete (6) is poured into the polygonal cross-section column to obtain the support column (3). Several of the aforementioned pillars (3) are connected by lacing material (4) to obtain a three-limb pillar (2); Several three-limb columns (2) are arranged at equal angles in the circumferential direction and fixedly connected by a horizontal ring truss (8) to obtain the first layer of lattice wind turbine tower; By using diagonal bracing (7), the first layer of lattice wind turbine towers and the second layer of lattice wind turbine towers that are adjacent to each other are fixedly connected. Repeat the above steps to obtain a three-limb lattice wind turbine tower.

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