Fabricated prestressed steel-concrete combined tower drum

Abstract

The invention provides a fabricated prestressed steel-concrete combined tower drum, and relates to the technical field of structural engineering.The technology includes the steps that the tower drum is divided into a plurality of standard sections from high to low along the height, each standard section comprises a drum body, the drum body is formed by uniformly and circumferentially arranging a plurality of profile steel, and an upper flange plate and a lower flange plate are arranged at the two ends of the drum body respectively; prestressed pipelines are arranged between every two adjacent profile steels at intervals, anchoring sleeves are arranged at the two ends of each prestressed pipeline, the anchoring sleeves are connected with the upper flange plate and the lower flange plate, and anchoring base plates are arranged on the anchoring sleeves; prestressed holes are formed in the upper flange plate and the lower flange plate corresponding to the anchoring sleeves.

Description

Technical Field

[0001] The present invention relates to the technical field of structural engineering, in particular to an assembled prestressed steel-concrete composite tower. Background Art

[0002] As a clean, renewable, and low-carbon energy source, wind power is attracting more and more attention and attention. In recent years, with the continuous and rapid development of wind power, wind power has developed towards large-capacity units (18MW+), high hubs (180m+), and long blades (140m+), which has put forward higher requirements on the supporting structure.

[0003] It is understood that for wind turbine towers exceeding 140m in height, the most commonly used tower structure is the "lower prestressed concrete tower + upper steel tower" structure, which has been widely used in actual projects. This tower structure has the following disadvantages:

[0004] (1) The size is large and inconvenient to transport, so it needs to be prefabricated in pieces. When the upper tower is prefabricated in a whole section, the length of the single section also needs to be short to facilitate transportation.

[0005] Currently, the bottom diameter of concrete towers is generally more than 8m. In order to meet transportation conditions, the lower tower needs to be prefabricated in pieces. When the diameter of the upper tower is smaller, the whole section is prefabricated, resulting in a large number of prefabricated components. They are assembled on site through hoisting, which requires a large amount of assembly work.

[0006] (2) The existing mixed tower has many joints and poor reliability.

[0007] The horizontal joints of concrete towers are generally bonded by grouting materials and concrete or structural adhesive and concrete. Since the longitudinal steel bars cannot pass through, the reliability of the connection is poor. The longitudinal joints of concrete towers are divided into dry and wet types. The dry connection uses arc-shaped bolts to connect prefabricated pipe segments and pour structural adhesive in the middle. The wet connection embeds U-shaped steel bars on the prefabricated components, sets longitudinal steel bars at the joints, and fills the joints with grouting materials. However, it requires high-altitude operation. In order to ensure the assembly accuracy, the process requirements are high.

[0008] (3) The transfer segment needs to be set

[0009] Since the top of the concrete tower and the bottom of the steel tower are inconsistent in size and material, a transition section is required. The current mainstream transition section type is reinforced concrete structure, which has large component size and dense steel bars.

[0010] (4) Prestressed construction needs to be carried out after installation is completed, and prestressed tensioning space needs to be set up in the foundation.

[0011] The construction sequence for a concrete tower is: factory prefabrication of reinforced concrete segments (tube segments) - on-site hoisting (assembly) - prestressing. Prestressing requires the tower to be installed, and the steel strands must be hoisted from high altitude. The tensioning ends are located within the foundation, which requires a large cavity for operation. This increases both the construction time and the installation workload. Furthermore, the amount of foundation concrete used is reduced, but the amount of foundation reinforcement required is increased.

[0012] (5) In order to reduce the weight of the tower and reduce the wall thickness of the tower, the existing concrete tower needs to use high-performance concrete (C80 and above).

[0013] (6) Risk of tower sweeping: During the operation of wind turbines, due to the deformation and deflection of the blades, especially at the blade tips, the wind load increases due to the high wind speed, resulting in significant tip deflection. When the increase in the tower diameter reduces the distance between the blade tip and the tower, if the deformation and deflection of the blade tip is too large, making the distance between it and the tower too small, tower sweeping may occur, that is, the blade tip touches the tower during operation. Due to the large diameter of the mixed tower, considering the requirements of the blade tip sweeping distance control value provided by the main engine manufacturer, it is difficult for the mixed tower to maintain a sufficient safe distance from the blade tip. Therefore, there is a certain risk of "tower sweeping".

[0014] A search revealed a publication number of CN112177857A titled "Prestressed Hollow Sandwich Steel Tube Concrete Lattice Hybrid Tower and Its Production and Installation Method." This invention relates to the fields of onshore and offshore wind power generation. The system includes a wind turbine, a steel tower, a tower transition section, a lattice tower, and a foundation. The foundation is precisely positioned using standard embedded parts; the corner columns of the lattice tower are bolted to the embedded parts in the foundation; four short I-shaped steel sections are arranged around the lower end of the steel tower; the tower transition section is composed of four concrete-filled box beams connected to the four short I-shaped steel sections at the lower end of the steel tower; the wind turbine is arranged on the steel tower; the lattice tower can be triangular or quadrilateral, and the corner columns are all made of hollow sandwich steel tube concrete, the hollow portion of which is a channel for tensioning prestressed tendons. The length of the components is standardized, and each component is connected by flanges; the cross bars and diagonal bars in the lattice tower are all made of steel tube concrete, and the connections between the components are all made of connecting plate bolts. However, the technical means adopted in this disclosure have the shortcomings of the aforementioned tower structure. Summary of the Invention

[0015] The present invention provides an assembled prestressed steel-concrete composite tower, the purpose of which is to solve at least one technical problem existing in the prior art mentioned in the background technology.

[0016] The present invention provides the following technical solutions to achieve the above objectives:

[0017] An assembled prestressed steel-concrete composite tower comprises a tower divided into a plurality of standard sections from high to low in height, each standard section comprising a cylinder body, the cylinder body being composed of a plurality of steel sections evenly arranged circumferentially, an upper flange and a lower flange being respectively provided at both ends of the cylinder body; prestressed pipes are arranged at intervals between two adjacent steel sections, anchor sleeves are provided at both ends of the prestressed pipes, the anchor sleeves are connected to the upper flange and the lower flange, and anchor pads are provided on the anchor sleeves; prestressed holes are opened on the upper flange and the lower flange at positions corresponding to the anchor sleeves; a reinforced concrete layer is provided on the outer sides of the steel sections and the prestressed pipes.

[0018] Furthermore, reinforcing ribs are provided on the inner and outer sides of the connection between the steel section and the upper flange and the lower flange.

[0019] Furthermore, bolts are arranged at intervals along the height direction on the steel sections and prestressed pipes.

[0020] Furthermore, the upper flange and the lower flange are both provided with bolt holes, and the bolt holes are circumferentially arranged on the inner and outer sides of the upper flange and the lower flange.

[0021] Furthermore, the diameter of the tower is gradually increased from top to bottom.

[0022] Furthermore, the steel section, prestressed pipe, anchor sleeve, upper flange and lower flange are made of Q355B steel.

[0023] Furthermore, the steel sections include H-shaped steel, channel steel, angle steel and I-shaped steel.

[0024] Beneficial effects

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] Compared to existing concrete tower structures, this invention exhibits a higher load-bearing capacity. Under the same height and load requirements, the invention can reduce the size and weight of the structure, thereby alleviating transportation difficulties and reducing the risk of tower sweeping with traditional tower structures. Compared to existing technologies, this invention reduces the construction difficulty of wind turbine tower assembly and the number of structural joints in the wind turbine tower. Installation requires only the sequential docking of standard segments and the bolted connection of upper and lower flanges. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 It is a schematic diagram of the local structure of the present invention;

[0029] Figure 3 It is a top view schematic diagram of the present invention;

[0030] Figure numerals: 1-lower flange; 2-upper flange; 3-anchor sleeve; 4-anchor pad; 5-prestressed pipe; 6-steel; 7-stiffening rib. DETAILED DESCRIPTION

[0031] To facilitate understanding of the present invention, the present application will be described more comprehensively below with reference to the relevant drawings; the drawings show preferred embodiments of the present invention, but the present invention can be implemented in many different forms and is not limited to the embodiments described herein; on the contrary, the purpose of providing these embodiments is to enable a more thorough and comprehensive understanding of the disclosed content of the present invention.

[0032] It should be noted that the terms “vertical”, “horizontal”, “up”, “down”, “left”, “right” and similar expressions used in this document are for illustrative purposes only and do not represent the only implementation method.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains; the terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention; the term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0034] Example. A prefabricated prestressed steel-concrete composite tower, the structure of which is referenced Figures 1 to 3 , including dividing the tower into several standard segments along the height from high to low, each standard segment includes a cylinder body, which is composed of several steel sections 6 evenly arranged circumferentially, with an upper flange 2 and a lower flange 1 provided at both ends of the cylinder body respectively; prestressed pipes 5 are arranged between two adjacent steel sections 6, with anchor sleeves 3 provided at both ends of the prestressed pipes 5, the anchor sleeves 3 are connected to the upper flange 2 and the lower flange 1, and anchor pads 4 are provided on the anchor sleeves 3; prestressed holes are opened on the upper flange 2 and the lower flange 1 at positions corresponding to the anchor sleeves 3; a reinforced concrete layer is provided on the outside of the steel sections 6 and the prestressed pipes 5. In order to facilitate the assembly between standard segments, the flange surfaces between the standard segments are fitted together, so the prestressed anchor shall not protrude from the flange surface; the present invention opens a prestressed hole on the flange, welds the anchor sleeve 3 concentrically with the prestressed hole, and welds the anchor pad 4 at the end of the anchor sleeve 3.

[0035] Stiffening ribs 7 are provided inside and outside the connection between the steel section 6 and the upper flange 2 and the lower flange 1. The stiffening ribs 7 are provided to improve the structural strength of the steel section 6 and the upper flange 2 and the lower flange 1, thereby improving the axial bearing capacity of the prestressed steel-concrete composite tower.

[0036] Bolts are arranged at intervals along the height direction on the steel section 6 and the prestressed pipe 5. The studs are provided to improve the bonding strength between the steel section 6, the prestressed pipe 5 and the concrete.

[0037] Bolt holes are provided on both the upper flange 2 and the lower flange 1, circumferentially arranged on the inner and outer sides of the upper and lower flanges 2 and 1. The tower diameter gradually increases from top to bottom. The steel sections 6, prestressed pipes 5, anchor sleeves 3, upper and lower flanges 2 and 1 are made of Q355B steel. The steel sections 6 include H-shaped steel, channel steel, angle steel, and I-shaped steel.

[0038] The method of using the present invention is as follows: the height and diameter of the prestressed steel-concrete composite tower are determined according to the requirements of the wind turbine project, the number of steel sections 6 and prestressed pipes 5 is determined, the steel sections 6 and prestressed pipes 5 are connected to the upper flange 2 and the lower flange 1 by welding, bolts are connected on the steel sections 6 and the prestressed pipes 5 by welding, and then a steel mesh is laid around the steel sections 6 and the prestressed pipes 5, a formwork is set up for concrete pouring, and the concrete completely wraps the steel sections 6, the prestressed pipes 5 and the steel mesh; after the concrete strength reaches the design requirements, the prestressed anchor cable is then installed in the prestressed pipes 5 and prestressing is performed, and after the tensioning design value is reached, concrete is poured into the prestressed pipes 5 and the anchor end is sealed, and finally the tower is transported to the project site for hoisting and installation, and several standard segments are docked with the flanges in turn and connected by bolts, thus completing the installation of the standard stage of the prestressed steel-concrete composite tower.

[0039] The present invention has carried out relevant structural verification calculations, and the following are the calculation results of the present invention:

[0040] Taking the actual dimensions of a concrete tower wind turbine project as an example, its cross-sectional diameter is 4080mm, the wall thickness is 320mm, and the concrete used is C60;

[0041] The cross-sectional diameter of the prestressed steel-concrete composite tower is 4080 mm, the wall thickness is 320 mm, the concrete is C60, 48 sections of steel (6) are used, and 48 prestressed pipes (5) are used; the cross-sectional bearing capacity comparison is as follows:

[0042]

[0043] As can be seen from the above table, under the same setting conditions (section diameter 4080mm, wall thickness 320mm, concrete C60), the existing concrete tower and the prestressed steel-concrete composite tower of the present invention have a 38% increase in cross-sectional bending stiffness, a 36% increase in cross-sectional shear stiffness, a 38% increase in cross-sectional axial stiffness, and an 82% increase in cross-sectional compressive bearing capacity.

[0044] The comparison of the cross-sectional dimensions of the concrete tower structure of the prior art and the prestressed steel-concrete composite tower structure of the present invention when they achieve the same cross-sectional bearing capacity is as follows:

[0045]

[0046] It can be seen from the above table that when the axial compressive strength bearing capacity of the existing concrete tower and the prestressed steel-concrete composite tower of the present invention is the same, the outer diameter of the prestressed steel-concrete composite tower of the present invention is 4080mm and the wall thickness is 320mm; while the outer diameter of the existing concrete tower is 7000mm and the wall thickness is 320mm.

[0047] Obviously, the above is only a partial embodiment of the present invention, not all embodiments. The above embodiments are not intended to limit the present invention. For those skilled in the art, the present invention can be modified and varied in various ways. Any combination, modification, equivalent replacement, improvement, and other embodiments that can be made by those of ordinary skill in the art within the spirit and principles of the present invention shall be within the scope of protection of the present invention.

Claims

1. An assembled prestressed steel-concrete composite tower, characterized by: The tower is divided into several standard sections from high to low in height, each standard section includes a cylinder body, which is composed of several steel sections (6) evenly arranged in a circumferential direction, and an upper flange (2) and a lower flange (1) are respectively provided at both ends of the cylinder body; a prestressed pipe (5) is arranged at intervals between two adjacent steel sections (6), and anchor sleeves (3) are provided at both ends of the prestressed pipe (5), the anchor sleeves (3) are connected to the upper flange (2) and the lower flange (1), and an anchor pad (4) is provided on the anchor sleeve (3); prestressed holes are opened on the upper flange (2) and the lower flange (1) at positions corresponding to the anchor sleeves (3); and a reinforced concrete layer is provided on the outer sides of the steel sections (6) and the prestressed pipe (5).

2. The prefabricated prestressed steel-concrete composite tower according to claim 1, characterized in that: Stiffening ribs (7) are provided on the inner and outer sides of the connection between the section steel (6) and the upper flange (2) and the lower flange (1).

3. The prefabricated prestressed steel-concrete composite tower according to claim 1, characterized in that: Bolts are arranged at intervals on the section steel (6) and the prestressed pipe (5) along the height direction.

4. The prefabricated prestressed steel-concrete composite tower according to claim 1, characterized in that: Bolt holes are provided on both the upper flange (2) and the lower flange (1), and the bolt holes are circumferentially arranged on the inner and outer sides of the upper flange (2) and the lower flange (1).

5. The prefabricated prestressed steel-concrete composite tower according to claim 1, characterized in that: The diameter of the tower is gradually increased from the top to the bottom.

6. The prefabricated prestressed steel-concrete composite tower according to claim 1, characterized in that: The material of the steel section (6), prestressed pipe (5), anchor sleeve (3), upper flange (2) and lower flange (1) is Q355B steel.

7. The prefabricated prestressed steel-concrete composite tower according to claim 1, characterized in that: The steel sections (6) include H-shaped steels, channel steels, angle steels and I-shaped steels.

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