A large-capacity fan space anti-torsion truss tower structure

Abstract

This invention belongs to the field of wind power tower equipment and discloses a large-capacity wind turbine spatial anti-torsion truss tower structure. Circumferentially distributed corner columns are arranged on the outer side of the inner core tube, and a ring truss is arranged between adjacent corner columns, forming a circumferentially closed rigid hoop for the outer frame tube, thus improving the local torsional stiffness of the outer frame tube itself. A radial truss is arranged between each corner column and the inner core tube. Several layers of radial and ring trusses are arranged along the corner columns from top to bottom. An outrigger truss is arranged between every two adjacent layers of radial trusses, forming a multi-layered spatial connection network between the inner core tube and the outer frame tube through the radial and outrigger trusses. When torsion occurs, the radial and outrigger trusses can constrain the relative rotation of the inner and outer tubes and lock the angular difference between them, ensuring uniform torque transmission throughout the radial and circumferential directions and multi-strut coordinated energy dissipation. This reduces the overall torsion angle of the tower and solves the fatigue damage and cracking problems caused by the small number of anti-torsion members and low static indeterminate redundancy in traditional four-column truss towers.

Description

Technical Field

[0001] This invention belongs to the field of wind power generation tower equipment and relates to a large-capacity wind turbine spatial anti-torsion truss tower structure. Background Technology

[0002] With the rapid development of the wind power industry towards large megawatts, ultra-high towers, and complex mountainous conditions, truss towers have become one of the mainstream tower types for onshore wind power with hub heights of 160m and above. Traditional wind turbine truss towers are four-column structures, widely used in the wind turbine tower field due to their advantages of light weight, low wind resistance, convenient segmented transportation, and high on-site assembly efficiency. However, as the capacity of onshore single units exceeds 10MW, the operating loads of wind turbines exhibit characteristics such as large nacelle eccentric bending moments, high aerodynamic torque amplitudes, and strong turbulent coupling effects. Existing truss tower structures are gradually revealing problems such as insufficient torsional resistance and limited structural stiffness, making it difficult to meet the long-term safe service requirements of ultra-large megawatt and ultra-high towers.

[0003] The existing truss tower adopts a force transmission form of "upper steel tower + transfer section + lower four-column truss". The entire load of the wind turbine is borne by the top transfer section, and then transferred to the lower truss tower. The four corner columns bear axial compression and bending moment loads, the steel strands running through the corner columns bear tensile loads, and the intersecting diagonal web members on the facade bear external torque. This structural system has the following shortcomings: (1) The four main columns form a square frame structure, and its quadrilateral structure has a rhomboid distortion degree of freedom. Under the action of the torsional moment generated by the operation of the wind turbine, the cross section of the tower is prone to diagonal slip and rhomboid deformation, resulting in a large amount of overall torsional deformation of the tower and an excessive torsional angle at the top of the tower.

[0004] (2) At present, the torsional bearing capacity of truss towers mainly relies on the cross diagonal web members on each facade to form a couple through tension and compression to resist external torque. The four-column structure only sets four sets of diagonal web members to participate in torsion resistance. The number of torsional force members is small and the static indeterminate redundancy of the structure is low, which makes the torsional stress highly concentrated in the local diagonal web members and node positions. The members are in a state of high amplitude alternating stress for a long time, which is very easy to cause fatigue damage, loosening or even cracking, seriously affecting the service safety and service life of ultra-high truss towers.

[0005] (3) In traditional truss towers, all upper vertical loads, bending moments, and torques are concentrated and transmitted through the transfer section, resulting in complex stress distribution and severe local stress concentration in the transfer section. To meet the load-bearing requirements, castings must be used in the key load-bearing areas of the transfer section, which is costly to manufacture. Furthermore, the castings are connected to ordinary steel components by welding, resulting in abrupt changes in stiffness and large residual stress in the weld area. Under reciprocating torsion and wind vibration, fatigue failure is highly likely to occur.

[0006] In summary, current ultra-high wind turbine truss towers generally suffer from technical pain points such as defects in structural torsional resistance mechanism, large torsional deformation, high fatigue risk, and poor stiffness stability throughout the entire life cycle. The industry urgently needs a new type of wind turbine truss tower structure that can eliminate rhomboid distortion defects from the structural topology and achieve high torsional resistance, high stiffness, and adaptive control. Summary of the Invention

[0007] The purpose of this invention is to solve the problems in the prior art and provide a large-capacity wind turbine space anti-torsion truss tower structure.

[0008] To achieve the above objectives, the present invention employs the following technical solution: A large-capacity wind turbine spatial anti-torsion truss tower structure includes an inner core tube and a steel tower tube connected sequentially from bottom to top, with blades installed at the upper end of the steel tower tube; The inner core tube is provided with circumferentially distributed corner columns on its outer side. A ring truss is provided between two adjacent corner columns. A radial truss is provided between each corner column and the inner core tube. The radial truss and the ring truss are arranged in several layers along the corner columns from top to bottom. An outrigger truss is provided between each two adjacent layers of radial truss.

[0009] A further improvement of the present invention is that: The corner posts are arranged to tilt inwards from bottom to top.

[0010] One end of the radial truss is connected to the outer wall of the inner core tube, and the other end is connected to the side wall of the corner column. The outrigger truss is inclined, with one end connected to the corner column and the other end connected to the inner core tube, and the outrigger truss is located between two adjacent radial trusses.

[0011] The corner column is composed of several steel-concrete composite sections spliced ​​together along the height direction.

[0012] A transition section is provided at the connection between the inner core tube and the steel tower tube, and the upper ends of the corner columns are all connected to the transition section.

[0013] The diameter of the inner core tube is less than or equal to the diameter of the steel tower tube.

[0014] The corner column is provided with a node plate, and the node plate is provided with an installation groove. The ring truss and the corner column are connected by a node connection plate. One end of the node connecting plate is connected to the mounting groove, and the other end is connected to the ring truss.

[0015] The node connecting plate, mounting groove, and ring truss are all provided with corresponding rivet holes. One end of the node connecting plate is embedded into the mounting groove, and the other end is embedded into the ring truss. The assembly of the node corner column and the ring truss is completed by installing ring groove rivets in the rivet holes.

[0016] The inner core tube or corner column is provided with a number of prestressed steel strands distributed axially.

[0017] The inner core tube is provided with a core tube foundation platform at its lower end, and the corner columns are provided with corner column foundation platforms at their lower ends.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a large-capacity wind turbine spatial anti-torsion truss tower structure. Circumferentially distributed corner columns are arranged on the outer side of the inner core tube, with ring trusses between adjacent corner columns, forming a circumferentially closed rigid hoop for the outer frame tube. This overcomes the rhomboid distortion degree of freedom defect of traditional quadrilateral truss towers, preventing diagonal slippage and section warping under torsion, thus improving the local torsional stiffness of the outer frame tube itself. Radial trusses are arranged between each corner column and the inner core tube, and several layers of radial trusses and ring trusses are arranged along the corner columns from top to bottom. Outrigger trusses are arranged between every two adjacent layers of radial trusses, making… The inner core tube and outer frame tube form a multi-layer spatial connection network through radial trusses and outrigger trusses. When torsion occurs, the radial trusses and outrigger trusses can constrain the relative rotation of the inner and outer tubes and lock the angular difference between the inner and outer tubes, so that the torque is uniformly transmitted in the radial and circumferential directions and the multi-member coordinated energy dissipation reduces the overall torsion angle of the tower and avoids the concentration of torsional stress at local members and nodes. This solves the fatigue damage and cracking problems caused by the small number of anti-torsion members and low static indeterminate redundancy of traditional four-column truss towers, avoids rhomboid distortion defects, and improves the overall torsional stiffness and fatigue resistance.

[0019] Furthermore, in this invention, the corner columns are arranged to tilt inwards from bottom to top, which reduces the cross-sectional size of the top of the tower, reduces the windward area and wind load force of the top area of ​​the tower, and ensures the structural stability of the ultra-large megawatt wind turbine under ultra-high tower conditions.

[0020] Furthermore, in this invention, the radial truss is horizontally connected between the inner core tube and the corner columns, and the outrigger truss is inclinedly arranged between two adjacent layers of radial trusses, with its two ends connected to the corner columns and the inner core tube respectively. This allows the inner core tube and the outer frame tube to form a multi-layer spatial rigid connection network through the horizontal radial truss and the inclined outrigger truss. When the structure is subjected to torsional loads, the horizontal radial truss can transmit the torque radially to the inner core tube, while the inclined outrigger truss simultaneously bears the vertical shear force and the horizontal torque, constraining the relative rotation of the inner and outer tubes and locking the rotation angle difference, thereby improving the torsional stiffness of the overall structure and reducing the torsional deformation at the top of the tower.

[0021] Furthermore, in this invention, the corner column is spliced ​​together from several steel pipe concrete segments along the height direction, so that the number of segments of the corner column can be flexibly adjusted according to the tower height.

[0022] Furthermore, in this invention, a transition section is provided at the connection between the inner core tube and the steel tower tube, and the upper ends of the corner columns are all connected to the transition section. This allows the vertical pressure transmitted by the upper steel tower tube to be transmitted to the inner core tube and the corner columns of the outer frame tube respectively through the transition section, forming a dual parallel force transmission path. This avoids the stress concentration problem caused by the entire load being concentratedly transmitted by the outer frame tube through the transition section in traditional structures. At the same time, the upper ends of the corner columns are all connected to the transition section to ensure the uniformity of stress on each limb of the outer frame tube and the symmetry of load distribution.

[0023] Furthermore, in this invention, corresponding rivet holes are provided on the node connecting plate, the mounting groove, and the ring truss. One end of the node connecting plate is embedded inside the mounting groove, and the other end is embedded inside the ring truss. The node assembly is completed by the rivet holes cooperating with the ring groove rivets. A double shear plane stress state is formed between the node plate and the ring truss, which improves the shear bearing capacity and connection stiffness of the node.

[0024] Furthermore, in this invention, several prestressed steel strands are arranged axially inside the inner core tube. The prestressed steel strands apply vertical prestress to the inner core tube, enabling the core tube to effectively resist tensile stress and delay concrete cracking when subjected to wind-induced horizontal loads and torsional loads. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure disclosed in an embodiment of the present invention; Figure 2 This is the basic diagram disclosed in the embodiments of the present invention; Figure 3 This is a structural diagram of the truss segment disclosed in an embodiment of the present invention; Figure 4 This is a top view of the truss section disclosed in an embodiment of the present invention. Figure 5 This is a transformation segment diagram disclosed in an embodiment of the present invention; Figure 6 This is a node connection diagram disclosed in an embodiment of the present invention; Figure 7 This is a construction flowchart disclosed in an embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of the installation of the first-floor corner pillars disclosed in an embodiment of the present invention.

[0028] Figure 9This is a schematic diagram of the truss segment hoisting construction disclosed in an embodiment of the present invention.

[0029] The components are: 1-Foundation cap system; 2-Corner column; 3-Inner core tube; 4-Outrigger truss; 5-Radial truss; 6-Ring truss; 7-Transition section; 8-Steel tower; 9-Main unit; 10-Blade; 11-Prestressed steel strand; 101-Corner column foundation; 1011-Anchor bolt upper anchor plate; 1012-Anchor bolt hole; 1013-Structural adhesive application area; 1014-Area where upper anchor plate meets corner column flange; 102-Core tube foundation cap; 103-Connecting beam; 201-First corner column; 202-Second corner column; 203-Third corner post; 204-Fourth corner post; 205-Fifth corner post; 206-Sixth corner post; 701-Flange; 702-Bolt hole; 12-Elevator; 13-Guide rope; 14-Temporary ground anchor; 15-Node plate; 16-Node connection plate; 17-Groove rivet. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0032] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0033] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0034] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0035] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0036] See Figures 1 to 9 The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 This embodiment discloses a large-capacity wind turbine spatial anti-torsion truss tower structure. The outer perimeter is a multi-column steel-concrete truss frame, while the inner perimeter is a centrally closed concrete core, forming an inner core-outer frame system. The structure includes an inner core 3 and a steel tower 8 connected sequentially from bottom to top. Blades 10 are located at the upper end of the steel tower 8. The main unit 9 is located at the blade 10. Circumferentially distributed corner columns 2 are arranged on the outer side of the inner core 3, with 6 or 8 columns evenly arranged in a circular pattern to form a closed spatial truss outer frame. The corner columns 2 are inclined inwards sequentially from bottom to top. A ring truss 6 is installed between adjacent corner columns 2, horizontally connected to form a spatial closed truss. A radial truss 5 is installed between each corner column 2 and the inner core 3, horizontally connected at one end to the outer wall of the inner core 3 and at the other end to the side wall of the corner column 2. Radial trusses 5 and annular trusses 6 are arranged in several layers along the height of corner columns 2, with one layer every 8m to 15m, generally at the same height as the segmented corner columns. An outrigger truss 4 is installed between every two adjacent layers of radial trusses 5. The outrigger truss 4 is inclined, with an angle of 45 to 60 degrees to the horizontal plane. One end of the outrigger truss 4 is connected to the corner column 2, and the other end is connected to the inner core tube 3. Both the outrigger truss 4 and the radial trusses 5 are made of steel, with cross-sections of steel pipes or structural steel. The radial trusses 5 and outrigger trusses 4 connect the inner core tube 3 and the outer corner columns 2, working together to withstand wind loads, nacelle eccentric torque, and seismic forces.

[0037] Furthermore, in this embodiment, a foundation platform system 1 is provided at the lower end of the large-capacity wind turbine spatial anti-torsion truss tower. The foundation platform system 1 includes a core tube foundation platform 102, and corner column foundation platforms 101 are arranged circumferentially around the core tube foundation platform 102. Adjacent corner column foundation platforms 101 are connected by connecting beams 103.

[0038] Corner column 2 is a steel-concrete composite structure. The steel pipes bear tensile forces, while the concrete bears compressive forces. The interior of the steel pipes is filled with micro-expansion concrete to ensure a tight bond between the steel pipes and concrete, leveraging the confinement characteristics of the steel-concrete composite structure. The micro-expansion concrete grade is greater than C60, specifically C80 or C90, and the steel pipe material strength is greater than Q355. Each corner column 2 is composed of 4 to 8 steel-concrete composite segments spliced ​​along its height. Adjacent steel-concrete composite segments are fixedly connected by flanges, high-strength bolts, and epoxy structural adhesive. Alternatively, only steel pipes can be used, followed by on-site pumping of concrete. The high-strength bolts are grade greater than 10.9. Each steel-concrete composite segment is 8m to 15m long, 8mm to 15mm thick, and 0.8m to 1.8m in diameter. The bottom truss section is 60m to 100m high. The bottom of corner column 2 is fixed to the wind turbine foundation using prestressed anchor cages and epoxy structural adhesive or grout. The upper corner column is connected to the transfer section 7 via flanges and bolts. The bottom corner columns are connected to the wind turbine foundation using prestressed anchor cages and epoxy structural adhesive.

[0039] Furthermore, it should be noted that in this embodiment, the number of corner posts 2 is greater than 4, but is not limited to 6 or 8.

[0040] Ring truss 6 is a pure steel pipe truss, with steel pipe wall thickness ranging from 4mm to 8mm, outer diameter from 200mm to 400mm, and cross-sectional shape of circular or rectangular. For example... Figure 6 As shown, a node plate 15 is installed on the corner column 2, and an installation groove is provided on the node plate 15. The ring truss 6 and the corner column 2 are connected by a node connecting plate 16. One end of the node connecting plate 16 is connected to the installation groove, and the other end is connected to the ring truss 6. Corresponding rivet holes are provided on the node connecting plate 16, the installation groove, and the ring truss 6. One end of the node connecting plate 16 is embedded into the installation groove, and the other end is embedded into the ring truss 6. The corner column 2 and the ring truss 6 are assembled by cooperating with the rivet holes and the ring groove rivets 17. The ring groove rivets 17 are arranged in a double shear pattern.

[0041] The inner core tube 3 is a reinforced concrete structure, a vertically continuous reinforced concrete core tube that runs the entire length of the tower. The wall thickness of the inner core tube 3 gradually decreases from bottom to top along the height direction, thickening at the bottom and decreasing layer by layer upwards. The inner core tube 3 can be cast in place or precast tower sections and then assembled on site. The diameter of the inner core tube 3 is less than or equal to the diameter of the steel tower tube 8. The inner core tube 3 is centrally located, with its center being the geometric center of the outer frame truss tower. The inner core tube 3 contains an elevator shaft, maintenance passage, and cables, integrating elevators 12, cables, and maintenance passages. Prestressed steel strands 11 can also be arranged inside the inner core tube 3. The height of the inner core tube 3 is consistent with the vertical height of the outer truss. The lower end of the inner core tube 3 is equipped with a core tube foundation 102, which is connected to the core tube foundation 102 by a flange. The lower end of the corner column 2 is equipped with a corner column foundation 101. Two adjacent corner column foundations 101 are connected by a connecting beam 103 to form an integral foundation system. The core tube foundation 102 is constructed with pile groups arranged in a circular symmetrical layout, and the corner column foundation 101 is constructed with pile groups arranged in a square symmetrical layout. The number of piles under each corner column foundation 101 is 4 or 9.

[0042] like Figure 5 As shown, a transition section 7 is installed at the connection between the inner core tube 3 and the steel tower tube 8. The upper ends of the corner columns 2 are all connected to the transition section 7. The transition section 7 is located between the inner core tube 3 and the steel tower tube 8, and is a steel-concrete composite structure with a height of 4.0m to 8.0m and a distance of 5m to 8m. Several anchoring points for connecting to the corner columns 2 are distributed circumferentially at the bottom of the transition section 7. A flange 701 is installed at the anchoring point, and bolt holes 702 are opened on the flange 701. The flange 701 is connected to the corner column 2 through the bolt holes 702. A prestressed steel strand anchoring area is provided in the middle and upper part. The top of the transition section 7 is connected to the steel tower tube 8 through a flange. The upper part of the inner core tube 3 is connected to the transition section 7 and the steel tower tube 8, and can directly bear part of the pressure of the steel tower tube 8, reducing the burden on the transition section.

[0043] The inner core tube 3 is also equipped with multiple prestressed steel strands 11. These prestressed steel strands 11 are filled epoxy-coated steel strands. The bottom of each prestressed steel strand 11 is anchored within the independent wind turbine foundation, and the top is anchored in the transition section anchorage area. The prestressed steel strands 11 can be arranged vertically along the interior of the inner core tube 3, or they can be distributed among the corner columns 2 and arranged along the inclination angle of the corner columns 2. The total number of prestressed steel strands 11 is greater than 70, and the ultimate tensile strength of the prestressed steel strands is 1860 N / mm².

[0044] The structure disclosed in this embodiment forms a dual lateral and torsional resistance system. The first line of defense is the inner core tube 3, which is reinforced concrete in the center and bears the main shear force and part of the torque. The second line of defense is the outer truss frame tube with 6 or 8 steel tube concrete members, which bears most of the overturning moment and additional torque. Under torsional load, the entire inner core tube 3 and the outer truss tower form a multi-layered spatial collaborative system within a tube, which is a highly redundant, statically indeterminate double-layer closed tube structure. The inner core tube 3 and the outer frame tube are circumferentially symmetrical, and the center of stiffness coincides with the geometric center, achieving centroid alignment and eliminating bending-torsional coupling at its source. Torque can be uniformly transmitted radially and circumferentially throughout the entire system, and multiple members cooperate to dissipate energy, thus eliminating the torsional deformation defects of quadrilateral trusses from the structural mechanism. The inner core tube 3 and the outer frame tube are connected by radial trusses 5 and outrigger trusses 4. One end of the radial trusses 5 and the outrigger trusses 4 is anchored to the inner core tube 3, and the other end is connected to the corner column 2 of the outer frame tube. When torsion occurs, the radial trusses 5 and the outrigger trusses 4 constrain the relative rotation of the inner and outer tubes, locking the difference in rotation angle between the inner and outer tubes, and significantly reducing the overall torsion angle. The ring truss 6 forms a rigid ring around the circumference, improving the local torsional stiffness of the outer frame tube itself. The diagonal web members are eliminated in the overall structure.

[0045] Example 2 This invention discloses a construction method for a large-capacity wind turbine spatial anti-torsion truss tower structure. The method is specifically designed for high-rise wind turbine towers with a multi-column steel-concrete outer truss frame and a closed core tube. The core principles are: first, integral foundation forming; second, vertical climbing of the inner core tube 3; third, segmented and synchronous hoisting of the outer tower columns; fourth, delayed matching installation of the inter-layer trusses; fifth, installation of the steel-concrete transition section; sixth, construction of the prestressed steel strands; and seventh, finishing at the top. This method is suitable for the construction of ultra-high wind turbine towers over 160m.

[0046] Step 1: Pre-construction preparations: The site is leveled and the hoisting equipment is set up. The lines are accurately laid out according to the hexagonal or octagonal axis of the tower. The center of the core tube and the positioning points of the 6 or 8 main tower columns on the periphery are marked. The axis deviation is strictly controlled to ensure the overall structure is circumferentially symmetrical.

[0047] Factory prefabrication: Standardized prefabrication of all steel-concrete composite main tower columns, radial trusses 6, outrigger trusses 4, ring trusses 5, core tube embedded steel sections and studs is completed in advance. Corrosion protection of steel components, stud welding, and pre-installation of anchor bars are completed ahead of schedule, reducing on-site high-altitude work. The steel-concrete connection node drawings are checked, and the embedded positions, elevations, and anchoring depths of steel components on each floor of the core tube are determined in advance to prevent later drilling and welding that could damage the structural integrity.

[0048] Step 2: Foundation Construction Pile foundation construction: First, construct the core tube foundation cap 102, and construct pile groups according to the circular symmetrical layout, with uniform pile top elevation to ensure uniform bearing capacity at each point; then construct the corner column foundation cap 101, and construct pile groups according to the square symmetrical layout, with 4 or 9 piles under each foundation, and uniform pile top elevation to ensure uniform bearing capacity at each point.

[0049] Foundation casting: Cast the core tube foundation foundation 102 and the outer corner column foundation 101, and connect the foundations with connecting beams 103 to form an integral foundation system.

[0050] Precise pre-embedding: Simultaneously pre-embed vertical anchor bars of the core tube, bottom steel embedded parts, and anchor bolts of the outer steel pipe corner columns in the core tube foundation 102 and the outer corner column foundation 101, strictly control the plane position and verticality, and use them as the benchmark for precise construction of the superstructure.

[0051] Wind turbine foundation acceptance: The positional error of the center point of the anchor plate 1011 on a single prestressed anchor bolt shall not exceed ±2mm, and the relative elevation error of the center points of the anchor plates 1011 on four anchor bolts shall not exceed ±2mm; the side lengths and diagonals shall be re-measured, and the deviation of the four side lengths of the foundation root shall not exceed ±5mm, and the deviation of the diagonal shall not exceed ±5mm. Otherwise, the wind turbine foundation construction unit shall rectify the situation before handing it over to the hoisting unit; the lattice tower can only be installed after the wind turbine foundation concrete reaches 75% of the design strength; the prestressed steel strands can only be tensioned after the wind turbine foundation concrete reaches 100% of the design strength.

[0052] Step 3: Core tube construction: The inner core tube 3 serves as the core carrier for structural shear and torsion resistance. It adopts a pre-climbing and layer-by-layer forming process, always maintaining the construction height of the core tube 8 to 15 meters higher than the outer frame structure, providing a precise benchmark and rigid support for the installation of the outer truss. The core tube wall is cast in layers using an intelligent climbing formwork system, with the bottom reinforced area formed first, and the wall reinforcement, restrained edge members, and opening reinforcement beams constructed simultaneously.

[0053] Layered Precision Embedding: Strictly adhering to the elevation of each layer of rigid partitions, extended steel brackets with studs and anchor bars are pre-embedded on the outer wall of the inner core tube 3. These pre-embedded components are welded and fixed to the main reinforcement of the tube body. The entire concrete pouring process is monitored to prevent displacement of the pre-embedded components. After each layer of the inner core tube 3 is poured, timely curing and inspection of verticality and flatness are conducted, and axial deviations are corrected to ensure the accuracy of the steel-concrete connection nodes. The pre-embedding of maintenance passages and pipelines on the inner side of the inner core tube 3 is carried out simultaneously to avoid secondary grooving later, which could damage the closed torsional section of the tube body.

[0054] Step 4: Segmented hoisting and placement of the outer corner columns After the inner core tube 3 is 8 to 15 meters higher, the construction of the outer frame tower columns will begin to ensure a reasonable height difference and coordinated stress distribution between the inner and outer structures. First, the structure of the anchor plate 1011 is described. The anchor plate 1011 is a circular structure with a circular through hole in the center. The outer perimeter of the circular through hole is an annular structural adhesive application area 1013. The outer perimeter of the structural adhesive application area 1013 is an annular area 1014 where the upper anchor plate and the corner column flange meet. Multiple anchor holes 1012 are opened circumferentially within the area 1014 where the upper anchor plate and the corner column flange meet.

[0055] First layer: Apply a layer of epoxy structural adhesive evenly to the joint area between the top surface of the anchor plate 1011 on the foundation anchor bolt and the concrete of the corner column interlayer (i.e., apply a layer of epoxy structural adhesive to the structural adhesive application area 1013), with a thickness of 1 to 4 mm. Then, apply two circles of sealant continuously and evenly in a "◎" pattern to the joint area between the upper anchor plate and the corner column flange (i.e., apply sealant to the joint area 1014 between the upper anchor plate and the corner column flange).

[0056] Main hoisting in coordination with auxiliary hoisting: Hoist the first corner column 201 to the designed position, aligning the flange hole at the bottom of the first corner column 201 with the foundation anchor bolts. After the flange hole of the first corner column 201 is fully inserted into the foundation anchor bolts, tighten the bolts of the foundation anchor bolts. Install temporary guy ropes 13 on the back side of the corner column, and attach the temporary guy ropes 13 to the back side of the flange of the first corner column 201. After hoisting the first corner column 201, pull the temporary guy ropes 13 to the temporary ground anchors 14. Hoist the second corner column 202 in the same way and position it correctly. The ring truss 6 is spliced ​​onto the surfaces of the first corner column 201 and the second corner column 202. The ring truss 6 is assembled on the ground. After the ring truss 6 assembly is completed, the lifting points are secured with wire ropes for hoisting. The ring truss assembly is rotated to the installation position, and the node connecting plate 16 is slowly inserted into the installation groove of the corresponding corner column node plate 15 and fixed with bolts. A fine-tuning allowance is left on the bolts to accommodate the subsequent truss assembly precision. After the ring truss 6 is installed in place, the remaining third corner column 203, fourth corner column 204, fifth corner column 205, and sixth corner column 206 of this layer are installed sequentially, along with the connecting ring truss 6. The hoisting of the corner columns and ring truss of the first-layer truss section is completed.

[0057] Elevation control: Always maintain the inner core tube 3 leading the outer tower column by 8 to 15 meters to prevent structural stiffness imbalance and installation benchmark deviation caused by the outer frame leading and the core tube lagging behind.

[0058] Step 5: Installation of the rigid interlayer connection system: This process is crucial for ensuring the overall torsional resistance of the inner and outer cylinders and eliminating relative rotation. It strictly follows the sequence of first installing the cantilever truss and then the radial truss.

[0059] Radial and outrigger truss installation: Using the pre-embedded steel bracket of the inner core tube 3 as a reference, the radial truss 5 and outrigger truss 4 are hoisted. The inner end is fixed to the pre-embedded steel with double-fixed friction bolts through full penetration welding, and the outer end is fixed to the outer tower column with double-fixed friction bolts through full penetration welding, so as to achieve rigid connection and deformation coordination between the inner and outer tubes.

[0060] Node reinforcement construction: For the steel-concrete connection area of ​​the inner core tube 3, locally thickened concrete hidden beams are poured, with additional denser stirrups and crack-resistant steel mesh, and embedded parts are wrapped to prevent tube wall cracking and steel-concrete debonding under reciprocating torsional loads. After the first-floor structure is installed, the upper tower is installed sequentially in the order of corner column 2, ring truss 6, outrigger truss 4, and radial truss 5, until all components below the transfer section are installed.

[0061] Step 6: Install the conversion section Before installing transition section 7, apply a layer of epoxy structural adhesive, 1 to 4 mm thick, evenly to the concrete surface at the top of the four corner columns of the truss section. Then, apply two continuous and even circles of sealant in a "◎" pattern to the flange surface at the top of the corner columns. After tightening the flange bolts to the required torque, smooth out any sealant squeezed out from the gaps. Use a crawler crane to slowly lift transition section 7 to the height above the installation tower, then slowly rotate the boom to position transition section 7 precisely at the center of the tower. During the positioning, the high-altitude signalman should prevent transition section 7 from colliding with surrounding components and constantly monitor for collisions or interference between components and the crawler crane boom. Since the nodes of the six corner columns need to be installed simultaneously during the hoisting of the transition section, when directing the connection between transition section 7 and the lower tower, if the distance between the two connecting flanges is greater than 10 mm before the corner column flanges of the transition section contact the upper flange of the tower, first use a punch to position and install the six corner columns on each connecting corner column before installing the flange bolts. After all bolts are installed, they are tensioned and tightened, completing the installation of the transition section.

[0062] Step 7: Full-height structural verification and overall reinforcement: After the entire tower construction is completed, the overall structural verticality, circumferential symmetry, and node connection accuracy are re-measured, and accumulated construction deviations are corrected. Specialized inspections are conducted on all steel-concrete composite joints, embedded corbel areas, and core tube opening reinforcement areas, and a comprehensive re-inspection of welds and bolt tightness is performed. The tower top reinforcement section is constructed as needed, the top truss structure is densified to weaken the seismic whiplash effect, and TMD damper installation interfaces are simultaneously reserved.

[0063] Step 8: Construction of prestressed steel strands: The prestressed steel strands can only be tensioned when the compressive strength of the concrete inside the corner column steel pipe reaches 80% of the design strength, the compressive strength of the wind turbine foundation concrete reaches 100% of the design strength, and the compressive strength of the epoxy structural adhesive is not less than 80% of the design strength of the concrete inside the steel pipe.

[0064] Clean up debris: Clean up concrete and related debris inside pipes and anchorages, as well as on surfaces and around the area.

[0065] Installation of tensioning anchors: Before installing the anchor rings, the steel strands must be cleaned thoroughly and free of any debris.

[0066] Jack installation: Insert the limiting plate, press the limiting plate against the working anchor ring, insert the jack into the single steel strand, and then tension the steel strands one by one after the end of the jack is against the end face of the limiting plate.

[0067] The tensioning sequence must be symmetrical: The oil pumps of the corresponding two strands are simultaneously activated to supply oil to the jacks. The jacks slowly maintain the load, and oil supply is stopped when the tension reaches 100% of the design stress. The length from the anchor point of the steel strand to the painted mark is measured, and the actual tensioning elongation is calculated. Corrosion protection: After tensioning, the excess exposed steel strand is cut off with a cutting machine, and after corrosion protection, a cap is installed. The designed steel strand length is increased by 1.5 meters, and the strands are pre-cut at the steel strand company, with the extrusion anchor pressed onto one end of the strand.

[0068] Step 9: Ancillary Structures and Finishing Work: The maintenance access roads, cable shafts, platform ladders, and other ancillary facilities inside the construction tower are arranged symmetrically to ensure quality and avoid additional eccentric loads. All steel components are coated with anti-corrosion paint, and the steel-concrete interface is waterproofed and sealed to prevent rust, water seepage, and cracking of embedded parts. The upper steel tower is installed. The nacelle hub blades are installed, and overall commissioning and final acceptance are completed.

[0069] It should be noted that the technical components involved in the construction method disclosed in this embodiment but not disclosed in this embodiment are all construction tools commonly used in the construction process in this field, so they will not be described in detail.

[0070] The embodiments of the present invention have the following advantages: First, a wind turbine tower tube-in-tube system combining a polygonal steel-concrete outer frame truss tube and a central closed core tube is disclosed: breaking through the geometric variable defects of the traditional four-column truss tower with quadrilateral shape, a 6 or 8-limb circumferentially symmetrical outer frame truss combined with a central full-height concrete core tube is adopted to form a double-layer closed tube statically indeterminate anti-torsional system, which completely eliminates inherent torsional defects such as rhomboid distortion, diagonal slip, and cross-sectional warping from the structural topology level, and significantly improves the overall torsional stiffness and fatigue resistance of ultra-high wind turbine towers.

[0071] Second, the traditional diagonal web members are eliminated, and the entire domain torsional resistance is achieved by relying on the ring truss 6, radial truss 5 and outrigger truss 4: the traditional four-column truss relies on only four sets of diagonal web members for torsional resistance, abandoning the weak mode of the traditional four-column truss that relies on only four sets of diagonal web members for torsional resistance. The outer rigid hoop is formed by the multi-layer ring truss, and the radial and diagonal outrigger trusses are used to transfer forces in space, thereby improving the static indeterminate redundancy of the structure, simplifying the node construction, reducing fatigue sources, and improving the stability of the tower throughout its entire life cycle.

[0072] Third, the inner core tube 3 can directly bear part of the load transmitted by the steel tower tube, reducing the stress on the transfer section: the central core tube can directly bear the vertical pressure and part of the torque of the upper steel tube, changing the single force transmission path of the traditional truss tower where all the loads are concentrated in the transfer section, solving the industry pain points of stress concentration in the transfer section, high cost of castings, and serious welding fatigue.

[0073] Fourth, the exclusive construction process of "three inner core tubes first, and inner and outer staggered layers simultaneously": adopting the construction procedure of overall foundation first, core tube climbing ahead of outer frame, sequential hoisting, layer-by-layer closure, and post-tensioning of prestress, to ensure the structural forming accuracy, symmetry, and coordinated stress characteristics, avoid residual torsional stress during construction, and ensure the maximum mechanical performance of the twin-tube system.

[0074] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A large-capacity wind turbine spatial anti-torsion truss tower structure, characterized in that, It includes an inner core tube (3) and a steel tower tube (8) connected sequentially from bottom to top, and the upper end of the steel tower tube (8) is provided with blades (10). The inner core tube (3) is provided with circumferentially distributed corner columns (2), and a ring truss (6) is provided between two adjacent corner columns (2). A radial truss (5) is provided between each corner column (2) and the inner core tube (3). The radial truss (5) and the ring truss (6) are arranged in several layers from top to bottom along the corner column (2), and an outrigger truss (4) is provided between each two adjacent layers of radial truss (5).

2. The large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 1, characterized in that, The corner posts (2) are arranged inwards from bottom to top.

3. The large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 1, characterized in that, One end of the radial truss (5) is connected to the outer wall of the inner core tube (3), and the other end is connected to the side wall of the corner column (2); The outrigger truss (4) is inclined, with one end connected to the corner column (2) and the other end connected to the inner core tube (3), and the outrigger truss (4) is located between two adjacent radial trusses (5).

4. The large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 1, characterized in that, The corner column (2) is composed of several steel-concrete composite sections spliced ​​together along the height direction.

5. A large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 1, characterized in that, A transition section (7) is provided at the connection between the inner core tube (3) and the steel tower tube (8), and the upper ends of the corner columns (2) are all connected to the transition section (7).

6. A large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 1, characterized in that, The diameter of the inner core tube (3) is less than or equal to the diameter of the steel tower tube (8).

7. A large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 1, characterized in that, The corner column (2) is provided with a node plate (15), and the node plate (15) has an installation groove. The ring truss (6) and the corner column (2) are connected by a node connection plate (16). One end of the node connecting plate (16) is connected to the mounting groove, and the other end is connected to the ring truss (6).

8. A large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 7, characterized in that, The node connecting plate (16), the mounting groove and the ring truss (6) are all provided with corresponding rivet holes. One end of the node connecting plate (16) is embedded in the mounting groove and the other end is embedded in the ring truss (6). The assembly of the node corner column (2) and the ring truss (6) is completed by installing ring groove rivets (17) in the rivet holes.

9. A large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 1, characterized in that, The inner core tube (3) or corner column (2) is provided with a number of prestressed steel strands (11) arranged axially.

10. A large-capacity wind turbine spatial anti-torsion truss tower structure according to claim 1, characterized in that, The inner core tube (3) is provided with a core tube foundation platform (102) at the lower end, and the corner column (2) is provided with a corner column foundation platform (101) at the lower end.

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