Annular prestress device and assembly, concrete tower drum and concrete wind turbine tower

Abstract

The invention discloses an annular prestress device, an annular prestress assembly, a concrete tower drum and a concrete wind turbine tower, the device is applied to a tower drum of a vertically-fragmented prestressed concrete wind turbine tower, and the device comprises prestressed tendons, prestressed tendon hole channels and an anchorage device system; after the prestressed tendon hole channels are annular along the tower drum, the two ends of each prestressed tendon hole channel extend to the inner wall of the tower drum in a staggered mode to form tensioning ends, and the tensioning ends are provided with anchorage device systems; the prestressed tendons penetrate through the prestressed tendon hole channels, and the two ends of the prestressed tendons are connected with the anchorage systems at the corresponding tensioning ends respectively for anchoring and fixing. The vertical segmented tower drum fixed by the circumferential prestress device is simple in structure, convenient and fast to construct and good in integrity, and can provide better torque and shear stress for large-scale and high-altitude operation of a wind turbine tower.

Description

Technical Field

[0001] The present invention relates to a circumferential prestressing device, component, concrete tower barrel and concrete wind turbine tower. Background Art

[0002] The ground support structure of a wind turbine for wind power generation traditionally uses a steel conical tower barrel, which consists of an upper tower and a lower foundation. With the rapid development of the wind power generation industry in China, the single-unit capacity of wind turbines is getting larger and larger. In order to effectively utilize the wind energy resources in low-wind speed areas, wind turbines are gradually developing towards large-scale and high-altitude. The hub height and stiffness requirements of the matching tower are also constantly increasing. Currently, traditional towers in China use steel structure towers. However, when the hub height exceeds 120m, due to the size limitation of the long-distance transportation of the steel tower barrel section, the tower resonance problem, and the requirements for frequent disassembly and assembly in the later stage, it is difficult to achieve an ideal effect between the construction, transportation, operation and maintenance of the flexible steel tower and the economic benefits, thus restricting the development of high-tower-barrel wind turbines.

[0003] In order to solve the above technical problems, a concrete-steel cylinder hybrid tower is adopted to reduce the height of the steel tower barrel and increase the hub height. The lower part of the concrete-steel cylinder hybrid tower uses a concrete tower barrel, the upper part uses a steel tower barrel, and a hollow conical cylinder reinforced concrete structure is used as a transition barrel section in the middle.

[0004] The existing transition barrel section forms a prestressed concrete tower barrel by prefabricating concrete vertical slices and assembling them. During the operation of the wind turbine, the torque and shear stress received by the tower structure pose challenges to the integrity of the assembled structure, especially in the variable-diameter conical transition barrel section. Chinese Patent CN201810181334.1 discloses a segmented prefabricated prestressed concrete tower barrel for a wind turbine. The concrete tower barrel is formed by stagger-connecting a bottom section, a top section and ten middle sections, and the segmentation method is horizontal segmentation; each section of the tower barrel is spliced by four identical 1 / 4 circular arc prefabricated concrete slices, and the slicing method is vertical slicing. The slices are connected circumferentially by bolts. After the external prestressed steel strands are tensioned and anchored, the whole tower barrel is in a pre-compressed state. This concrete tower barrel can increase the hub height and meet the requirements of large-scale and high-altitude of wind turbines, but the assembled structure is complex and the integrity of the torque and shear stress is not good. Summary of the Invention

[0005] The present invention provides a circumferential prestressing device, component, concrete tower barrel and concrete wind turbine tower. The vertical-slice tower barrel fixed by the circumferential prestressing device has a simple structure, convenient construction and good integrity, and can provide better torque and shear stress for the large-scale and high-altitude operation of the wind turbine tower.

[0006] To achieve the object of the present invention, the present invention provides a circumferential prestressing device, which is applied to the tower barrel of a prestressed concrete wind turbine tower with vertical segments. The device includes prestressing tendons, prestressing tendon ducts and an anchorage system. Among them,

[0007] After the prestressing tendon ducts are formed in a ring along the tower barrel, both ends thereof extend to the inner wall of the tower barrel in a staggered manner to form tensioning ends, and an anchorage system is provided at each tensioning end; the prestressing tendons pass through the prestressing tendon ducts, and both ends thereof are respectively connected to the anchorage systems at the corresponding tensioning ends for anchoring.

[0008] The circumferential prestressing device of the present invention prestresses and fixes the tower barrel composed of vertical segments in the circumferential direction, improving the integrity of the tower barrel. Moreover, compared with the existing vertical segments connected by bolts, this circumferential prestressing device is convenient for construction and the quality is controllable; in addition, expensive grouting materials are saved, and the material utilization efficiency, precast assembly efficiency and scale of the precast concrete tower barrel are improved.

[0009] In the present invention, the annular prestressing tendon ducts are segmented and embedded in several vertical segments enclosing the tower barrel, and one of the vertical segments is used for the two ends of the prestressing tendon ducts to extend to the inner wall of the tower barrel in a staggered manner and form tensioning ends. That is, the staggered part of the two ends of the prestressing tendon ducts and the tensioning ends of the prestressing tendon ducts are both located on the same arc-shaped vertical segment.

[0010] In the present invention, the anchorage system includes a single-hole anchorage, an anchor ring, an anchor backing plate and spiral steel bars. Preferably, the anchorage system adopts the B&S system, and the B&S system includes accessories such as a Z15 type wedge-type single-hole anchorage, an anchor ring, an anchor backing plate and spiral steel bars. More preferably, the anchor backing plate is selected from Q345 steel plate or ribbed cast iron anchor backing plate.

[0011] According to the circumferential prestressing device of the present invention, preferably, the prestressing tendon includes a steel strand bundle with several steel strands arranged in the center, an anti-corrosion grease layer is coated on the outer side of the steel strand bundle, and a PE layer is coated on the outer side of the anti-corrosion grease layer.

[0012] As a more preferable technical solution of the present invention, the steel strand can adopt a high-strength low-relaxation steel strand.

[0013] According to the circumferential prestressing device of the present invention, preferably, the prestressing tendon duct is a plastic pipe, and the plastic pipe is arranged on the steel bar framework of the concrete tower barrel.

[0014] In the embodiment of the present invention, the prestressing tendon duct adopts a plastic pipe.

[0015] According to the circumferential prestressing device of the present invention, preferably, the prestressing tendon ducts at the joints of adjacent vertical segments are connected by a reducing sleeve that faces the opposite vertical segment and has a gradually increasing diameter.

[0016] As a specific technical solution of the present invention, the prestressed tendon ducts adopt plastic pipes, and variable-diameter sleeves with diameters gradually increasing towards the opposite vertical segment are provided at both ends of the prestressed tendon ducts on each vertical segment. By adopting the above-mentioned variable-diameter sleeves, adjacent vertical segments can be more accurate during the threading of the prestressed tendons, which is convenient for operation.

[0017] According to a circumferential prestressing device of the present invention, preferably, the vicinity of the tensioning end of the prestressed tendon duct is constrained on the annular prestressed tendon duct by anti-burst steel bars. That is, the vicinity of the tensioning end refers to the prestressed tendon duct extending after the two ends of the prestressed tendon duct are staggered, and is constrained on the corresponding annular prestressed tendon duct by anti-burst steel bars.

[0018] According to a circumferential prestressing device of the present invention, preferably, the tower barrel is located in the conical transition barrel section.

[0019] According to a circumferential prestressing device of the present invention, preferably, the prestressed tendons are unbonded prestressed tendons.

[0020] In addition, the present invention also provides a concrete tower barrel, which is formed by circumferentially connecting several arc-shaped vertical segments to form a conical frustum structure. The several vertical segments are fixedly connected by the above-mentioned circumferential prestressing device; the staggered parts at both ends of the prestressed tendon duct and the tensioning end of the prestressed tendon duct are all located on the same arc-shaped vertical segment.

[0021] According to a concrete tower barrel of the present invention, preferably, 2-5 sets of circumferential prestressing devices are arranged at intervals from bottom to top on the tower barrel.

[0022] Furthermore, the present invention also provides an installation method for a concrete tower barrel as described above, and the installation method includes:

[0023] (1) Preparing vertical segments: During the preparation of the vertical segments, the circumferential prestressed tendon ducts and the anchor plates of the anchor system are pre-embedded.

[0024] (2) Threading: The circumferential prestressed tendons are threaded before the vertical joints of the vertical segments are closed.

[0025] (3) Tensioning: After the concrete strength and vertical joints of each vertical segment meet the standards, double-end circumferential prestressing is carried out. After the tensioning is completed, the steel strands are cut off by a grinding wheel disc.

[0026] In the present invention, the steps for preparing the vertical segments are as follows: First, the plastic pipes are circumferentially fixed on the steel bar skeletons of the corresponding vertical segments. Among them, both ends of the plastic pipes on each vertical segment are connected with variable-diameter sleeves with diameters gradually increasing towards the opposite vertical segment; then, cement is poured and cured to form the vertical segments.

[0027] In the present invention, one of several vertical segments is used to set the staggered positions at both ends of the prestressed tendon duct and is provided with a tensioning end of the prestressed tendon duct, and an anchorage system is arranged at the tensioning end. The circumferential prestressed tendon duct and the anchor backing plate are pre-embedded in the precast yard, and the circumferential prestressed tendons are threaded before the vertical joints of the tower barrel wall are closed.

[0028] The present invention also provides a concrete wind turbine tower, which includes a transition cylinder section formed by connecting several concrete tower barrels as described above end to end.

[0029] In some embodiments of the present invention, the concrete wind turbine tower is composed of a concrete base, a transition cylinder section and a steel tower; preferably, the transition cylinder section is formed by connecting conical frustum-shaped tower barrels end to end in sequence.

[0030] The present invention also provides a spliced tower barrel assembly, including: a plurality of vertical segments that can be spliced into a frustum structure, and prestressed tendon ducts for prestressed tendons to pass through are pre-embedded in each vertical segment. When the plurality of vertical segments are spliced into a frustum structure, the prestressed tendon ducts therein are spliced into one or more independent annular ducts. The two free ends of at least one annular duct are staggered in a single vertical segment and extend to the inner circumferential surface of the single vertical segment, and anchor parts are pre-embedded in the section between the two free ends of the prestressed tendon duct of the single vertical segment and the staggered position. The anchor parts are used to anchor the prestressed tendons passing through the annular duct.

[0031] The anchor parts are specifically, for example, anchor backing plates.

[0032] The construction process of the tower barrel fixed by the circumferential prestressing device of the present invention is simple, the use space is flexible, the construction speed is fast, and the construction cost is low. By fixing and installing in the circumferential direction, it can provide better torque and shear stress for the large-scale and high-altitude operation of the wind turbine tower, and the integrity is good.

[0033] As a more optimal technical solution of the present invention, the unbonded prestressed tendons can be configured in a curve to adapt their shape to the external load bending moment diagram, and the role of the prestressed tendons can be fully exerted.

[0034] Furthermore, the tensioning of the prestressed steel strands does not require grouting, the product quality is stable, and the prestress loss is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic horizontal sectional view of a circumferential prestressing device of the present invention;

[0036] Figure 2 It is a schematic cross-sectional view of the prestressed tendons of a circumferential prestressing device of the present invention;

[0037] Figure 3Partial schematic diagram of the variable-diameter sleeve arrangement at the vertical segmentation of a concrete tower barrel of the present invention;

[0038] Figure 4 is Figure 1 Partial enlarged view of part A of;

[0039] Among them, 1 - vertical segmentation, 2 - variable-diameter sleeve, 3 - prestressed tendon duct, 4 - tension end, 5 - anti-burst steel bar, 6 - spiral steel bar, 7 - anchor backing plate, 8 - single-hole anchor, 9 - prestressed tendon, 10 - inner wall of the tower barrel, 11 - steel strand, 12 - anti-corrosion grease layer, 13 - PE layer, 14 - vertical joint. Specific implementation manner

[0040] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0041] Embodiment 1

[0042] As Figures 1-4 shown, a circumferential prestressing device of Embodiment 1 of the present invention is applied to the tower barrel of a vertically segmented prestressed concrete wind turbine tower, and includes a prestressed tendon 9 which is a non-bonded prestressed tendon, a prestressed tendon duct 3 and an anchor system; the specific structure is as follows:

[0043] The prestressed tendon 9 includes a steel strand bundle with several steel strands 11 arranged in the center. The outer side of the steel strand bundle is coated with an anti-corrosion grease layer 12, and the outer side of the anti-corrosion grease layer 12 is coated with a PE layer 13; the steel strand 11 can adopt a high-strength low-relaxation steel strand.

[0044] The prestressed tendon duct 3 is formed by a plastic pipe fixed on the steel bar framework of the tower barrel and arranged along the circumferential direction of the tower barrel. The two ends of the prestressed tendon duct 3 are staggered and then continue to extend until they are connected to the anchor system on the inner wall 10 of the tower barrel; the prestressed tendon 9 passes through the prestressed tendon duct 3, and both ends of it are respectively connected to the anchor system through the ends of the prestressed tendon duct 3 for anchoring. Variable-diameter sleeves 2 with diameters gradually increasing towards the opposite vertical segmentation are provided at both ends of the prestressed tendon duct 3 of each vertical segmentation 1; the prestressed tendon duct near the tension end 4 is constrained on the corresponding circumferential prestressed tendon duct 3 by anti-burst steel bars.

[0045] The anchor system is a B&S system, including a Z15 type wedge-type single-hole anchor 8, an anchor ring, an anchor backing plate 7 and a spiral steel bar 6.

[0046] Embodiment 2

[0047] Embodiment 2 provides a concrete tower barrel. The concrete tower barrel is formed by circumferentially connecting several arc-shaped vertical segments 1 to form a frustum structure. Three sets of circumferential prestressing devices provided in Embodiment 1 are arranged at the bottom of the tower barrel, and there is a spacing between each set of circumferential prestressing devices in the vertical direction; each vertical segment 1 is circumferentially enclosed and fixedly connected through the circumferential prestressing device; among them, one of the several arc-shaped vertical segments 1 is used to set the two ends of the prestressing tendon duct to be staggered and provided with a tension end 4 of the prestressing tendon duct 3, and an anchor system is arranged at the tension end 4.

[0048] The installation method of the tower barrel in Embodiment 2 includes:

[0049] (1) Prepare vertical segments: First, fix the plastic pipe circumferentially on the steel bar framework of the corresponding vertical segment. Among them, the two ends of the plastic pipe on each vertical segment 1 are connected with reducing sleeves 2 with gradually increasing diameters; then, pour cement to solidify to form a vertical segment 1 with a prestressing tendon duct; the two ends of the plastic pipe on one of the several vertical segments 1 extend staggeredly to the inner wall 10 of the tower barrel of the vertical segment, and an anchor system is arranged at the tension end 4. The anchor system needs to be pre-embedded when pouring cement, and a hole is pre-opened in the center of the anchor backing plate 7 for convenient tendon threading.

[0050] (2) Thread the tendon: Enclose several vertical segments to form a frustum, and complete the tendon threading of the circumferential prestressing tendon 9 before the vertical joint 14 of the vertical segment is closed;

[0051] (3) Tension: After the concrete strength of each vertical segment 1 and the vertical joint 14 meet the standards, carry out the circumferential prestressing tension at both ends. After the tension is completed, the redundant steel strands 11 are cut off with a grinding wheel disc.

[0052] In the installation method of the embodiment, the circumferential prestressing tendon duct and the anchor backing plate are pre-embedded in the prefabrication yard, the circumferential prestressing tendon is threaded before the vertical joint of the tower barrel wall is closed, and the prestressing steel strand tensioning does not require grouting.

[0053] Embodiment 3

[0054] Embodiment 3 provides a concrete wind turbine tower. The concrete wind turbine tower includes a concrete base at the bottom, an intermediate transition cylinder section and a steel tower at the top; among them, the transition cylinder section is formed by connecting several concrete tower barrels provided in Embodiment 2 end to end.

[0055] Embodiment 4

[0056] Based on the same inventive concept as the aforementioned embodiment, this embodiment 4 provides a spliced ​​tower assembly, comprising: a plurality of vertical segments that can be spliced ​​into a conical structure, each vertical segment having a prestressed tendon channel embedded therein for passing prestressed tendons, when the plurality of vertical segments are spliced ​​into a conical structure, the prestressed tendon channels therein are spliced ​​into one or more independent annular channels, the two free ends of at least one annular channel are staggered in a single vertical segment and extend to the inner circumference of the single vertical segment, and the section between the two free ends and the staggered position of the prestressed tendon channel of the single vertical segment is pre-embedded with anchor parts, and the anchor parts are used to anchor the prestressed tendons passing through the annular channels.

[0057] The anchor part is, for example, an anchor pad.

[0058] The various embodiments of the present invention are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments.

[0059] The protection scope of the present invention is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the scope and spirit of the present invention. If these changes and modifications fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include these changes and modifications.

Claims

1. A circumferential prestressing device, characterized in that, the device is applied to the tower barrel of a vertically segmented prestressed concrete wind turbine tower, and the device includes prestressing tendons, prestressing tendon ducts, and an anchor system; wherein, after the prestressing tendon ducts form a ring along the tower barrel, both ends thereof staggeredly extend to the inner wall of the tower barrel to form tensioning ends, and an anchor system is provided at each tensioning end; the prestressing tendons pass through the prestressing tendon ducts, and both ends thereof are respectively connected to the anchor systems at the corresponding tensioning ends for anchoring and fixing.

2. The circumferential prestressing device according to claim 1, characterized in that, the prestressing tendons include a steel strand bundle with several steel strands arranged in the center, an anti-corrosion grease layer is coated on the outer side of the steel strand bundle, and a PE layer is coated on the outer side of the anti-corrosion grease layer.

3. The circumferential prestressing device according to claim 2, characterized in that, the prestressing tendon ducts are plastic pipes, and the plastic pipes are arranged on the steel bar framework of the tower barrel.

4. The circumferential prestressing device according to claim 1, characterized in that, the prestressing tendon ducts at the joints of adjacent vertically segmented parts are connected by a reducing sleeve with a gradually increasing diameter towards the opposite vertically segmented part.

5. The circumferential prestressing device according to claim 1, characterized in that, the vicinity of the tensioning end of the prestressing tendon duct is constrained on the annular prestressing tendon duct by anti-burst steel bars.

6. The circumferential prestressing device according to claim 1, characterized in that, the anchor system includes a single-hole anchor, an anchor ring, an anchor backing plate, and spiral steel bars.

7. A spliced tower barrel assembly, characterized in that, it includes: a plurality of vertically segmented parts that can be spliced into a frustum structure, and prestressing tendon ducts for passing prestressing tendons are pre-embedded in each vertically segmented part. When the plurality of vertically segmented parts are spliced into a frustum structure, the prestressing tendon ducts therein are spliced into one or more independent annular ducts, and the two free ends of at least one annular duct stagger in a single vertically segmented part and extend to the inner circumferential surface of the single vertically segmented part, and anchor parts are pre-embedded in the section between the two free ends of the prestressing tendon duct of the single vertically segmented part and the staggered position, and the anchor parts are used for anchoring the prestressing tendons passing through the annular duct.

8. A concrete tower barrel, characterized in that, the concrete tower barrel is formed by circumferentially connecting several circular arc-shaped vertically segmented parts to form a conical frustum structure, and the several vertically segmented parts are fixedly connected by the circumferential prestressing device according to any one of claims 1-6; the staggered positions at both ends of the prestressing tendon duct and the tensioning ends of the prestressing tendon duct are all located on the same circular arc-shaped vertically segmented part.

9. The concrete tower barrel according to claim 8, characterized in that, 2-5 sets of circumferential prestressing devices are arranged at intervals from bottom to top in the concrete tower barrel.

10. A concrete wind turbine tower, characterized in that, it includes a transition barrel section, and the transition barrel section is formed by connecting several concrete tower barrels according to claim 8 or 9 end to end.

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