A spread foot group structure type tower suitable for large wind turbine generator

Abstract

The application discloses a lattice tower suitable for large wind turbine units, which comprises a steel tower cylinder, a conversion node and a lattice tower, wherein the lattice tower comprises an expanded foot section, a straight section and a variable angle section connecting the expanded foot section and the straight section, the straight section is located above the range of blade tip, and the expanded foot section is located below the range of blade tip; the variable angle section is provided with a prestressed cable bundle channel along the axial direction, a smooth inner convex structure is formed on the position of the prestressed cable bundle turning to the turning side, the cross section of the prestressed cable bundle channel at the smooth inner convex structure is a bell-shaped hole with one big end and one small end, the small end of the bell-shaped hole is a circular arc section with a diameter larger than the diameter of the prestressed cable bundle, the small end of the bell-shaped hole is directed to the direction of the prestressed cable bundle turning, and the shape of the bell-shaped hole gradually decreases from the two ends of the smooth inner convex structure to the central hole, so that the smooth inner convex structure is formed. The prestressed cable bundle can be controlled and uniformly turned, and the prestress loss is reduced.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to an extended-leg combined lattice tower suitable for large wind turbine units. Background Technology

[0002] With the rapid development of wind power as a representative of clean energy, the trend towards larger wind turbines has become increasingly apparent in recent years in order to continuously improve wind resource utilization and return on investment. This is reflected in the continuous increase in single-unit capacity and blade length. These factors have placed more stringent requirements on wind turbine towers and become a bottleneck restricting the development of larger wind turbines. On the one hand, wind turbine towers need to have higher load-bearing capacity to cope with more severe load environments; on the other hand, wind turbine towers need to reach greater heights to lift the ever-growing wind turbine blades.

[0003] Traditional wind turbine towers are poorly adapted to large wind turbine units. For example, monotube steel towers are prone to problems such as wall resonance, excessive steel plate thickness, and processing difficulties, and their applicable construction height is typically around 120m. Monotube hybrid towers, on the other hand, are prone to problems such as excessively large precast concrete components, difficulty in ensuring prefabrication and construction quality, and transportation difficulties, and their applicable height is typically around 180m. Against this backdrop, lattice-type wind turbine towers have become a more promising choice for supporting structures of large wind turbine units due to their advantages such as high component load-bearing efficiency, convenient transportation and hoisting, and convenient and reliable connections.

[0004] Chinese invention patent application number 202411591277.6 discloses a lattice-type wind turbine tower, including a top tower section, a transition section, and a lattice section. The top of the transition section is fixed to the top tower section, and the top of the lattice section is fixed to the transition section. The lattice section includes several corner posts and several reinforcing members. All corner posts form a corner post frame, and the tops of all corner posts are fixed to the transition section. The reinforcing members are connected to two adjacent corner posts along the side of the corner post frame. Each corner post has a corner post inflection point, and the corner post bends outward from the corner post frame at the corner post inflection point. The height of the corner post inflection point is configured to be lower than or equal to the lowest height of the fan blade tip, ensuring that the blade will not collide with the tower during operation. This allows the taper of the lattice section below the corner post inflection point to be flexibly adjusted, resulting in higher structural efficiency and less material usage. Furthermore, by adjusting the taper of the lattice section, the tower frequency can be flexibly adjusted, thereby avoiding the resonance range of the wind turbine and ensuring the safety of the tower.

[0005] The above-mentioned scheme, which involves expanding the legs below the blade range, is more suitable for cases with longer blades. However, it also leads to problems such as tower angle changes and prestressed cable strand reversal. This requires special tower forms and targeted structural measures, making the manufacturing process of the tower columns with angle changes complex and difficult to process. It also results in non-standard tower column specifications, which hinders large-scale production. In addition, existing technologies also have the problem of severe prestress loss at angle changes during prestressed cable strand tensioning. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides an extended-leg combined lattice tower suitable for large wind turbine units.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention provides a lattice-type tower with extended legs suitable for large wind turbine units, comprising a steel tower, a conversion node, and a lattice-type tower. The lattice-type tower includes an extended leg section, a straight section, and a variable-angle section connecting the extended leg section and the straight section. The straight section is located above the blade tip, and the extended leg section is located below the blade tip. The variable angle section is provided with a prestressed cable bundle channel along its axial direction. The prestressed cable bundle channel forms a smooth inward convex structure facing the turning side at the position where the prestressed cable bundle turns. The cross-section of the prestressed cable bundle channel at the smooth inward convex structure is a bell-shaped hole with one end larger than the other. The small end of the bell-shaped hole is an arc segment with a diameter larger than the diameter of the prestressed cable bundle. The small end of the bell-shaped hole faces the direction of the prestressed cable bundle turning, and the shape of the bell-shaped hole gradually decreases from both ends of the smooth inward convex structure to the central hole, thereby forming a smooth inward convex structure.

[0008] This invention provides an expanded-leg combined lattice tower suitable for large wind turbine units. Further, the variable-angle section includes an outer steel pipe, an upper inner steel pipe and a lower inner steel pipe located at both ends inside the outer steel pipe, and an inner lining steel plate located in the center inside the outer steel pipe. The upper inner steel pipe, the lower inner steel pipe, and the inner lining steel plate enclose a prestressed cable bundle channel. The inner lining steel plate forms a smooth, convex structure. Filler material is provided between the outer steel pipe and the prestressed cable bundle channel.

[0009] The present invention provides an expanded-leg combined lattice tower suitable for large wind turbine units. Further, an inner ring plate is provided between the inner lining steel plate and the outer steel pipe, and the inner ring plate is provided with a bell-shaped hole adapted to the cross section of the inner lining steel plate.

[0010] The present invention provides an expanded-leg combined lattice tower suitable for large wind turbine units. Further, the inner ring plate is provided with three intervals along the axial direction of the inner lining steel plate, namely an upper inner ring plate, a middle inner ring plate and a lower inner ring plate. The bell-shaped hole on the middle inner ring plate is smaller than the bell-shaped hole on the upper inner ring plate and the lower inner ring plate.

[0011] The present invention provides an expanded-leg combined lattice tower suitable for large wind turbine units. Further, the outer steel pipe is provided with a web member connection part, and the web member connection part is provided with longitudinal stiffening ribs at corresponding positions. The longitudinal stiffening ribs are located between the outer steel pipe and the upper inner steel pipe, and between the outer steel pipe and the lower inner steel pipe.

[0012] The present invention provides an extended-leg combined lattice tower suitable for large wind turbine units. Further, the lattice tower includes four prestressed steel pipe concrete tower columns and a number of diagonal web members and transverse web members distributed between the prestressed steel pipe concrete tower columns.

[0013] The present invention provides an extended-leg combined lattice tower suitable for large wind turbine units. Further, the upper part of the conversion node is connected to the steel tower tube, and the lower part is connected to the lattice tower. The conversion node includes four lower connecting parts connected to the prestressed steel pipe concrete tower column and an upper connecting part connected to the steel tower tube. The upper end of the lower connecting part is provided with a prestressed cable anchor for anchoring the upper end of the prestressed cable bundle.

[0014] The present invention provides an expanded-leg combined lattice tower suitable for large wind turbine units. Further, the prestressed cable anchor includes an upper cover plate, a lower cover plate, and a ring rib and a radial rib connected between the upper cover plate and the lower cover plate. The upper cover plate and the lower cover plate are provided with cable through holes.

[0015] This invention provides an extended-leg combined lattice tower suitable for large wind turbine units. Further, the lattice tower is provided with distributed foundations, each located below a column of the lattice tower. Each distributed foundation includes piles and a pile cap. An operating cavity is provided within the pile cap, and cable-passing holes and manholes communicating with the operating cavity are pre-reserved on the pile cap. The lower end of the prestressed cable bundle is anchored within the operating cavity by prestressed cable anchors.

[0016] The present invention provides an expanded-leg combined lattice tower suitable for large wind turbine units. Furthermore, the top of the pier is provided with a through hole communicating with the operating cavity, and a balancing steel cylinder is provided at the through hole. The lower end of the balancing steel cylinder is connected to a prestressed cable anchor.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This application adds a corner section, which is a separate component independent of the tower column members. This corner section allows for simultaneous tower column angle changes and prestressed cable strand reversal, facilitating manufacturing and ensuring uniformity in the form and structure of the tower column members, thus promoting large-scale production. During prestressed cable strand tensioning, it enables automatic convergence and smooth reversal, reducing prestress loss caused by reversal. 2. By using bell-shaped holes, this special shape of opening can ensure as much space as possible for cable threading, so that the prestressed cable bundles automatically converge towards the center after tensioning and basically maintain the cross-sectional shape before turning. On the one hand, it can reduce the prestress loss caused by turning, and on the other hand, it can avoid the prestressed cable bundles contacting the hole wall after changing direction, thus avoiding additional prestress loss. 3. The lattice tower of this application meets the load-bearing capacity and fatigue resistance requirements of the support structure of large-capacity wind turbine units, breaks through the blade length limitation, and is convenient to produce and transport, and easy and reliable to install; 4. The bell-shaped cross-section formed in this application can control the cross-sectional shape of the prestressed cable bundle, which is especially important when there is a large difference between the channel and the cable bundle size. In contrast, the traditional bend pipe directly turns, and the cable bundle will be flattened. If the cross-sectional shape is not maintained, the tower will vibrate back and forth under wind load, and slippage and wear may occur continuously between individual cables.

[0018] The invention will now be further described with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the prestressed steel-concrete composite tower column of the present invention; Figure 3 This is a schematic plan view of the connection between the tower column and the web member of the present invention; Figure 4 This is a schematic diagram of the conversion node of the present invention; Figure 5 This is a planar schematic diagram of the prestressed cable anchor of the present invention; Figure 6 This is a schematic elevation view of the prestressed cable anchor of the present invention; Figure 7 This is a schematic diagram of the basic structure of the present invention; Figure 8 This is a schematic diagram of the variable angle segment installation structure of the present invention; Figure 9 This is a schematic diagram of the variable angle segment structure of the present invention; Figure 10 This is a planar schematic diagram of the connection between the variable angle segment and the web member of the present invention; Figure 11 This is a schematic elevation view of the variable angle section connecting the web member of the present invention; Figure 12 This is a planar schematic diagram of the variable angle segment of the present invention at the inner ring plate; Figure 13 This is a schematic diagram of the inner ring plate of the present invention; Figure 14 This is a schematic diagram of the installation of the low-friction plate of the present invention.

[0020] Figure label: 1. Steel tower; 2. Transition node; 2.1 Lower connection; 2.2 Upper connection; 2.3 Prestressed cable anchor; 2.31 Upper cover plate; 2.32 Lower cover plate; 2.33 Ring rib; 2.34 Radial rib; 3. Lattice tower; 3.1 Straight section; 3.2 Expanded leg section; 3.3 Variable angle section; 3.31 Upper tower column connection; 3.32 Lower tower column connection; 3.33 Web member connection; 3.34 External steel pipe; 3.35 Upper inner steel pipe; 3.36 Lower inner steel pipe; 3.37 Inner lining steel plate; 3. 4. Prestressed steel-concrete composite tower column; 3.41. Outer steel pipe; 3.42. Inner steel pipe; 3.43. Concrete; 3.5. Diagonal web members; 3.6. Horizontal web members; 3.7. Longitudinal stiffening ribs; 3.8. Upper inner ring plate; 3.81. Central hole; 3.82. Side hole; 3.9. Middle inner ring plate; 3.10. Lower inner ring plate; 3.11. Low-friction plate; 4. Foundation; 4.1. Pile; 4.2. Foundation; 4.3. Operating cavity; 4.4. Cable threading hole; 4.5. Manhole; 4.6. Balance steel cylinder; 5. Wind turbine unit; 6. Prestressed cable. Detailed Implementation

[0021] like Figure 1-14 As shown, the present invention discloses an extended-leg combined lattice tower suitable for large wind turbine units, including a steel tower 1, a conversion node 2, a lattice tower 3 and a distributed foundation 4. The upper end of the steel tower 1 is connected to the wind turbine unit 5, and the lower end is connected to the conversion node 2; the upper end of the conversion node 2 is connected to the steel tower 1, and the lower end is connected to the lattice tower 3; the lower part of the lattice tower 3 is connected to the distributed foundation 4.

[0022] The lattice-type tower 3 is a prestressed steel-concrete composite frame with an expanded foot. It includes a straight section 3.1, an expanded foot section 3.2, and a variable angle section 3.3. The straight section 3.1 is located above the blade tip, with a smaller outer profile of the tower body cross section and vertically arranged tower columns to avoid tower sweeping. The expanded foot section 3.2 is located below the blade tip, and the tower columns change angle near the blade tip through the variable angle section 3.3 of the fittings. The outer profile of the tower body cross section gradually expands downward to improve the rigidity and load-bearing capacity of the tower.

[0023] The lattice-type tower 3 includes four prestressed steel-concrete composite tower columns 3.4 and several diagonal web members 3.5 and transverse web members 3.6 distributed among the prestressed steel-concrete composite tower columns 3.4. The diagonal web members 3.5 and transverse web members 3.6 are all steel pipes and are connected to the prestressed steel-concrete composite tower columns 3.4 by bolt joints.

[0024] The prestressed steel-concrete composite tower column 3.4 comprises an outer steel pipe 3.41, an inner steel pipe 3.42, and concrete 3.43 filling the space between the outer and inner steel pipes 3.41 and 3.42. A through-hole is formed within the inner steel pipe 3.42 for tensioning the prestressing cables 6. The concrete 3.43 is prefabricated in the factory, and prestressing is applied on-site using post-tensioning. The anchoring ends are located at the distributed foundation 4 and the transfer node 2, respectively. By filling the tower column with concrete 3.43, a joint working mechanism is formed, significantly improving the tower column's load-bearing capacity and fatigue resistance. Prestressing the tower column is to prevent the concrete 3.43 from cracking under tension during operation. For ease of transportation, the tower column is divided into several sections, connected by flanges. The concrete 3.43 sections at the joints are connected on-site using adhesive. The tower column has a thickened inner steel pipe 3.42 at the connection with the web members, and longitudinal stiffening ribs 3.7 are installed at corresponding positions on the web member connection plates to strengthen the joint area and form an integrated load-bearing structure.

[0025] The variable-angle section 3.3 includes a turning part, an upper tower column connection part 3.31, a lower tower column connection part 3.32, and a web member connection part 3.33. The upper tower column connection part 3.31 is a flange connection used to connect to the upper tower column, and the flange angle is consistent with the upper tower column flange angle. The lower tower column connection part 3.32 is also a flange connection used to connect to the lower tower column, and the flange angle is consistent with the lower tower column flange angle. The web member connection part 3.33 is a steel plate, arranged at the position where web members need to be connected, and its shape is coordinated with the distribution of web members. Bolt holes are pre-drilled on it.

[0026] The turning section includes an outer steel pipe 3.34, an upper inner steel pipe 3.35 and a lower inner steel pipe 3.36 located at both ends inside the outer steel pipe 3.34, and an inner lining steel plate 3.37 located in the center inside the outer steel pipe 3.34. The upper inner steel pipe 3.35, the lower inner steel pipe 3.36, and the inner lining steel plate 3.37 enclose and form a prestressed cable bundle channel. The inner lining steel plate 3.37 is supported and its shape is adjusted by an upper inner ring plate 3.8, a middle inner ring plate 3.9, and a lower inner ring plate 3.10. At the turning position of the prestressed cable bundle, it forms a smooth inner convex structure according to the required shape, so that the prestressed cable bundle can be turned in a controllable and uniform manner.

[0027] The web member connection 3.33 is provided with longitudinal stiffening ribs 3.7 at the corresponding positions. The longitudinal stiffening ribs 3.7 are located between the outer steel pipe 3.34 and the upper inner steel pipe 3.35, and between the outer steel pipe 3.34 and the lower inner steel pipe 3.36.

[0028] The inner steel plate 3.37 is covered with a low-friction plate 3.11 to facilitate the tensioning of the prestressed cable bundles and reduce prestress loss. The outer steel plate 3.37 of the corner generally does not come into contact with the prestressed cable bundles, so the low-friction plate 3.11 is not required. The space between the outer steel pipe 3.34 and the prestressed cable bundle channel is filled with concrete 3.43 or high-strength grout to ensure the rigidity and strength of the turning part.

[0029] The upper inner ring plate 3.8, the middle inner ring plate 3.9, and the lower inner ring plate 3.10 have similar shapes. Taking the upper inner ring plate 3.8 as an example, it has a central hole 3.81 and a side hole 3.82. The central hole 3.81 is an eccentric bell-shaped hole with one end larger than the other. The larger end is an arc segment with the same outer diameter as the upper inner steel pipe 3.35, and the smaller end is an arc segment with a diameter slightly larger than the prestressed cable bundle. The concave part of the arc segment faces the turning side, and the center is located at the center of the upper inner ring plate 3.8. This special shape of the hole, while ensuring as much space as possible for cable threading, allows the prestressed cable bundle to automatically converge towards the center after tensioning and basically maintain the cross-sectional shape before turning. On the one hand, it can reduce the prestress loss caused by turning. On the other hand, it can avoid the prestressed cable bundles contacting the hole wall after changing direction, which would cause additional prestress loss.

[0030] The central hole 3.81 of the inner ring plate 3.9 is smaller than the central hole 3.81 of the upper inner ring plate 3.8 and the lower inner ring plate 3.10 to complete the turning of the 6 prestressed cable bundles, forming a smooth inner convex through hole structure with large upper and lower ends and small center.

[0031] The turning node 2 is made of steel and includes four lower connecting parts 2.1 connected to the prestressed steel tube concrete tower column 3.4 and an upper connecting part 2.2 connected to the steel tower tube 1, all of which are connected by flanges.

[0032] The upper end of the lower connecting part 2.1 is provided with a beam-type prestressed cable anchor 2.3 for anchoring the upper end of the prestressed cable 6. It includes an upper cover plate 2.31, a lower cover plate 2.32, and a ring rib 2.33 and a radial rib 2.34 connecting the upper cover plate 2.31 and the lower cover plate 2.32. The upper cover plate 2.31 and the lower cover plate 2.32 are provided with cable through holes corresponding to the position of the prestressed cable bundle, which can adapt to the high-level prestressing application and anchoring requirements of large wind turbine units 5 and high towers, and solve the problem of large deformation of traditional plate-type prestressed anchors under high-level prestressing.

[0033] The distributed foundation 4 is in the form of a pile cap, and there are four of them, located under the four tower columns. Each foundation 4 includes a pile 4.1 and a pile cap 4.2. In order to meet the requirements of prestressing application, a prestressing operation cavity 4.3 is set in the middle of the pile cap 4.2, and cable-passing holes 4.4 and manholes 4.5 are reserved. The top of the pile cap 4.2 has a through hole communicating with the operation cavity 4.3. In order to prevent the top of the pile cap 4.2 from local pressure failure due to high-level prestressing, a balancing steel cylinder 4.6 is set at the through hole. The lower end of the balancing steel cylinder 4.6 is connected to the prestressing cable anchor 2.3 for anchoring the lower end of the prestressing cable 6.

[0034] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A lattice-type tower structure suitable for large wind turbine generators, comprising a steel tower, a transition node, and a lattice-type tower, characterized in that, The lattice-type tower includes an extended leg section, a straight section, and a variable-angle section connecting the extended leg section and the straight section. The straight section is located above the blade tip, and the extended leg section is located below the blade tip. The variable angle section is provided with a prestressed cable bundle channel along its axial direction. The prestressed cable bundle channel forms a smooth inward convex structure facing the turning side at the position where the prestressed cable bundle turns. The cross-section of the prestressed cable bundle channel at the smooth inward convex structure is a bell-shaped hole with one end larger than the other. The small end of the bell-shaped hole is an arc segment with a diameter larger than the diameter of the prestressed cable bundle. The small end of the bell-shaped hole faces the direction of the prestressed cable bundle turning, and the shape of the bell-shaped hole gradually decreases from both ends of the smooth inward convex structure to the central hole, thereby forming a smooth inward convex structure.

2. The extended-leg combined lattice tower for large wind turbines according to claim 1, characterized in that, The variable angle section includes an outer steel pipe, an upper inner steel pipe and a lower inner steel pipe located at both ends inside the outer steel pipe, and an inner lining steel plate located in the center inside the outer steel pipe. The upper inner steel pipe, the lower inner steel pipe and the inner lining steel plate enclose and form a prestressed cable bundle channel. The inner lining steel plate forms a smooth inner convex structure. Filler material is provided between the outer steel pipe and the prestressed cable bundle channel.

3. A lattice-type tower with extended legs suitable for large wind turbine units according to claim 2, characterized in that, An inner ring plate is provided between the inner lining steel plate and the outer steel pipe, and the inner ring plate is provided with a bell-shaped hole adapted to the cross section of the inner lining steel plate.

4. A lattice-type tower with extended legs suitable for large wind turbine units according to claim 3, characterized in that, The inner ring plate is provided with three rings at intervals along the axial direction of the inner lining steel plate, namely the upper inner ring plate, the middle inner ring plate and the lower inner ring plate. The bell-shaped hole on the middle inner ring plate is smaller than the bell-shaped hole on the upper inner ring plate and the lower inner ring plate.

5. A lattice-type tower with extended legs suitable for large wind turbine units according to claim 2, characterized in that, The outer steel pipe is provided with a web member connection part, and the web member connection part is provided with a longitudinal stiffening rib at a corresponding position. The longitudinal stiffening rib is located between the outer steel pipe and the upper inner steel pipe, and between the outer steel pipe and the lower inner steel pipe.

6. A lattice-type tower with extended legs suitable for large wind turbine units according to claim 1, characterized in that, The lattice-type tower includes four prestressed steel-concrete composite tower columns and several diagonal and transverse web members distributed between the prestressed steel-concrete composite tower columns.

7. A lattice-type tower with extended legs suitable for large wind turbine units according to claim 6, characterized in that, The transition node is connected to a steel tower at the top and a lattice tower at the bottom. The transition node includes four lower connecting parts connected to the prestressed steel pipe concrete tower column and an upper connecting part connected to the steel tower. The upper end of the lower connecting part is provided with a prestressed cable anchor for anchoring the upper end of the prestressed cable bundle.

8. A lattice-type tower with extended legs suitable for large wind turbine units according to claim 7, characterized in that, The prestressed cable anchor includes an upper cover plate, a lower cover plate, and a ring rib and a radial rib connecting the upper cover plate and the lower cover plate. The upper cover plate and the lower cover plate are provided with cable through holes.

9. A lattice-type tower with extended legs suitable for large wind turbine units according to claim 1, characterized in that, The lattice-type tower is provided with distributed foundations, which are located below the tower columns of the lattice-type tower. Each distributed foundation includes piles and a pile cap. The pile cap has an operating cavity, and the pile cap has reserved cable-passing holes and manholes that communicate with the operating cavity. The lower end of the prestressed cable bundle is anchored in the operating cavity by prestressed cable anchors.

10. A lattice-type tower with extended legs suitable for large wind turbine units according to claim 9, characterized in that, The top of the pier is provided with a through hole communicating with the operating cavity, and a balancing steel cylinder is provided at the through hole. The lower end of the balancing steel cylinder is connected to a prestressed cable anchor.

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