UHPC (Ultra High Performance Concrete)-coated hybrid wind power tower drum

Abstract

The utility model discloses a UHPC (Ultra High Performance Concrete)-coated hybrid wind power tower drum which comprises a concrete tower drum positioned at the middle lower part, a steel tower drum is fixed at the top of the concrete tower drum, and the bottom of the concrete tower drum is fixed on a foundation; the concrete tower drum is composed of concrete drum sections which are sequentially stacked and connected from bottom to top. Wherein the concrete shell sections comprise a top concrete shell section located at the topmost part, a plurality of middle concrete shell sections located in the middle and a bottom concrete shell section located at the bottom. The advantages of the steel structure and the concrete structure are combined, so that the upper part and the lower part of the tower drum give full play to the characteristics of respective materials respectively, the two materials of UHPC and NC act synergistically, the stress performance is better exerted, the mixed tower structure has the advantages of high overall strength, good shock resistance, good corrosion resistance and the like, and the service life of the tower drum is prolonged. The concrete tower drum is simple in structural form, clear in force transmission path, low in construction difficulty and easy to implement.

Description

Technical Field

[0001] The utility model relates to the technical field of wind power generation, in particular to a hybrid wind power tower tube outsourced with UHPC. Background Art

[0002] As an important clean energy, wind power generation has the characteristics of mature technology, low risk, low cost and significant scale benefits. In order to improve and stabilize production capacity, wind turbines are becoming larger, resulting in a significant increase in operating loads and impeller size, and the height and cross-section of the lower supporting tower will also increase accordingly, which brings great difficulties to the prefabrication, transportation and assembly of wind turbine towers. As a tall structure, the wind turbine is equipped with a large rotor and nacelle on the top of the tower. During operation, it is subject to complex environmental loads such as strong winds, waves and even strong earthquakes, which puts higher performance requirements on its strength and stiffness. As the main load-bearing structure of the wind turbine, the wind turbine tower is subject to the combined effects of reciprocating wind loads, deadweight, pressure and bending moment generated by the wind turbine hub during operation, and is in an extremely complex stress state. It is necessary to ensure that it has sufficient strength, stiffness, stability, torsion resistance and fatigue resistance.

[0003] At present, there are three main types of wind turbine towers: steel towers, concrete towers, and steel-concrete hybrid towers. Traditional steel towers have advantages such as light weight and short construction period, but when the tower height is high, its bottom diameter is large, transportation is difficult, and durability is poor. Although concrete towers have the advantages of high rigidity, good stability, corrosion resistance, low cost and maintenance cost, the height of concrete towers is limited due to the large deadweight of concrete. In addition, its construction period is long, and the manufacturing and transportation costs are relatively high. At the same time, with the continuous increase in wind turbine capacity and tower height, it is often necessary to increase the tower cross-section, wall thickness or reinforcement ratio to ensure structural safety; however, due to the limitations of material properties, manufacturing process and transportation conditions, if the ultra-high wind turbine tower continues to use existing materials and structural forms, it may lead to difficulties in the preparation of prefabricated components, complex and long on-site construction, low durability and economy, etc. In addition, the method of reducing the deadweight of the tower to increase its height is to use UHPC to obtain higher unit strength, but the cost of UHPC is high, so it is necessary to improve the existing tower structure. Utility Model Content

[0004] In order to solve the above technical problems, the utility model proposes a hybrid wind power tower with UHPC outsourcing.

[0005] The purpose of the utility model is achieved through the following technical solutions:

[0006] A hybrid wind power tower with UHPC outer covering comprises a concrete tower in the middle and lower part, a steel tower is fixed on the top of the concrete tower, and the bottom is fixed on a foundation; the concrete tower is composed of concrete barrel sections stacked and connected in sequence from bottom to top; wherein the concrete barrel sections comprise a top concrete barrel section at the top, a plurality of middle concrete barrel sections in the middle, and a bottom concrete barrel section at the bottom; a first flange is fixed on the top of the top concrete barrel section, a second flange and a third flange are respectively fixed on the top and the bottom of the middle concrete barrel section, and a fourth flange is fixed on the bottom of the bottom concrete barrel section; a plurality of prestressed tendon channels are evenly arranged along the circumference of the first flange, the second flange, the third flange, and the fourth flange; the through-length prestressed tendons sequentially pass through the first flange, the second flange, the third flange, and the fourth flange to apply prestress to the concrete barrel section to form a whole; the outer side of the concrete barrel section is a UHPC shell, and the inner side is ordinary concrete; the UHPC shell and the ordinary concrete are fixedly connected by anchoring steel bars buried inside.

[0007] As a further improvement, the first flange, the second flange, the third flange and the fourth flange are all fixed with preset vertical steel bars, and the preset vertical steel bars are buried in ordinary concrete.

[0008] As a further improvement, a steel cage is embedded in the ordinary concrete, and preset vertical steel bars extend into the steel cage.

[0009] As a further improvement, the steel cage comprises a plurality of vertical longitudinal bars arranged along the circumference of the concrete cylinder segment, and a plurality of circumferential stirrups are bundled around the outer circumference of the vertical longitudinal bars; and the anchoring steel bars are fixed on the steel cage.

[0010] As a further improvement, the anchoring steel bar is oval in shape and is exposed outside the ordinary concrete to form a "∩"-shaped structure.

[0011] As a further improvement, a plurality of prestressed anchor bolts are arranged circumferentially on the top of the first flange, and the prestressed anchor bolts are fixedly connected to the steel tower.

[0012] A further improvement is that the number of prestressed tendon holes on the second flange and the third flange is . times the number of prestressed tendon holes on the first flange and the fourth flange; the prestressed tendon holes of the second flange and the third flange are also passed through segmented prestressed tendons, and the segmented prestressed tendons include upper segmented prestressed tendons and lower segmented prestressed tendons; the top end of the upper segmented prestressed tendon is anchored on the upper surface of the first flange, and the bottom end passes through the second flange and the third flange in sequence and is anchored on the bottom surface of the third flange of the middle concrete cylinder section in the middle; the bottom end of the lower segmented prestressed tendon passes through the prestressed tendon hole of the fourth flange and is anchored on the foundation, and the top end passes through the third flange and the second flange in sequence and is anchored on the top surface of the second flange of the middle concrete cylinder section in the middle.

[0013] As a further improvement, the segmented prestressed tendons and the full-length prestressed tendons are arranged alternately.

[0014] The beneficial effects of the utility model are:

[0015] Combining the advantages of steel structure and concrete structure, the upper and lower parts of the tower give full play to the characteristics of their respective materials. The concrete tower section adopts prefabricated assembly construction method, which can significantly ensure the construction quality and improve the construction efficiency. Taking full advantage of the excellent material properties of ultra-high performance concrete such as strength, stiffness, and durability, the synergistic effect of UHPC and NC materials better exerts the force performance, so that the mixed tower structure has the advantages of high overall strength, good seismic resistance, and good corrosion resistance. It is expected to solve the problems of local performance exceeding the limit and poor durability of ordinary concrete towers, and improve the structural reliability and safety of wind power towers. The use of UHPC shell instead of replacing all with UHPC concrete towers reduces the amount of UHPC and avoids the high cost of using all UHPC, making this tower structure economical. The sections of the steel tower are connected by bolts, and the sections of the concrete tower are formed into a whole by applying prestressed prestressed tendons. The structure is simple, the force transmission path is clear, the construction difficulty is low, and it is easy to implement. In addition, the alternating arrangement of full-length prestressed tendons and segmented prestressed tendons increases the redundancy of the structure and avoids the impact on structural safety due to relaxation or breakage of some prestressed tendons. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described with reference to the accompanying drawings, but the contents in the accompanying drawings do not constitute any limitation to the present invention.

[0017] Figure 1 This is a structural diagram of a steel-concrete wind turbine tower;

[0018] Figure 2 This is a schematic diagram of the top concrete cylinder section;

[0019] Figure 3 This is a schematic diagram of the middle concrete cylinder section;

[0020] Figure 4 This is a schematic diagram of the bottom concrete cylinder section;

[0021] Figure 5 It is a schematic diagram of the interface between the inner and outer layers of concrete in the concrete cylinder;

[0022] Figure 6 It is a schematic diagram of the interface between the inner and outer layers of concrete in the concrete cylinder;

[0023] Figure 7 This is a schematic diagram of the pouring connection between the concrete cylinder section and the flange;

[0024] Figure 8Schematic diagram of staggered tensioning of full-length and segmented prestressed tendons.

[0025] Among them, 1 is a steel tower, 2 is a concrete tower, 3 is a concrete cylinder section, 4 is ordinary concrete, 5 is a UHPC shell, 6 is a vertical longitudinal reinforcement, 7 is annular stirrups, 8 is an anchor steel bar, 10 is a preset vertical steel bar, 11 is a top concrete cylinder section, 12 is a middle concrete cylinder section, 13 is a bottom concrete cylinder section, 20 is a general term for flanges, 21 is a first flange, 22 is a second flange, 23 is a third flange, 24 is a third flange, 25 is a prestressed tendon channel, 26 is a full-length prestressed tendon, 27 is an upper segmented prestressed tendon, 28 is a lower segmented prestressed tendon, 30 is a prestressed anchor bolt, and 100 is a foundation. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and examples.

[0027] Example 1

[0028] like Figure 1-Figure 8A hybrid wind power tower with UHPC as shown is composed of an upper pure steel tower and a lower concrete tower. The concrete tower is a hollow truncated cone and is prefabricated in sections, that is, the tower is divided into several concrete sections along the height direction and assembled on site. During on-site assembly, multiple vertical sections are connected by horizontal joint grouting, and pre-pressure is applied by prestressed steel strands to compress the sections to form an integral tower. The concrete section mainly includes an inner layer of ordinary concrete and an outer layer of UHPC shell. It can be cast in a whole ring, or cast in pieces as needed and then assembled in a ring in a whole ring. In the inner layer of ordinary concrete, vertical longitudinal reinforcement is evenly arranged in the circumferential direction, and circumferential stirrups are evenly arranged in the vertical direction, and are tied together with vertical steel bars to form a steel cage. Anchor steel bars are arranged on the interface between the UHPC shell and the ordinary concrete beam, and the anchor steel bars are all elliptical. At the connection between the vertical longitudinal reinforcement and the annular stirrups, anchor steel bars are added. The anchor steel bars are tied and welded to form a whole with the steel cage. After pouring ordinary concrete, they are exposed in a "∩" shape to strengthen the connection between the UHPC shell and ordinary concrete. Then the UHPC shell is poured to form a whole. A number of high-strength prestressed anchor bolts are set on the top surface of the top concrete cylinder section to connect the bottom of the steel tower. A number of high-strength prestressed anchor bolts are evenly arranged along the circumference. A first flange is set on the top of the top concrete cylinder section, a second flange and a third flange are set on the upper and lower surfaces of the middle concrete cylinder section, and a fourth flange is set on the bottom surface of the bottom concrete cylinder section. Vertical steel bars are preset on the flange, and the vertical steel bars are evenly arranged along the circumference and are tightly combined with the concrete through pouring. A number of prestressed tendon holes are evenly arranged along the circumference on the flange. The number of prestressed tendon holes in the first flange is equal to that of the fourth flange, and the number of prestressed tendon holes in the second flange is equal to that of the third flange, and the number is 1.5 times that of the first and second flanges. The prestressed tendon holes of the second flange and the third flange are aligned one by one. The prestressed tendons include a number of full-length prestressed tendons and a number of segmented prestressed tendons. The full-length prestressed tendons and segmented prestressed tendons are fixedly arranged on the inner side of the concrete tower along the direction of the truncated cone generatrix. The lower end of the full-length prestressed tendon passes through the fourth flange of the bottom concrete cylinder section and is anchored on the concrete foundation, and the upper end passes through the third flange and the second flange and is anchored on the first flange. The segmented prestressed tendons are divided into upper and lower sections. The lower part of the lower prestressed tendon also passes through the fourth flange and is anchored on the concrete foundation, and the upper part passes through the third flange and is anchored on the second flange; the upper part of the upper prestressed tendon is anchored on the first flange, and the lower part passes through the second flange and is anchored on the third flange. The full-length prestressed tendons and segmented prestressed tendons are alternately arranged in sequence along the circumferential direction.

[0029] The manufacturing steps are as follows: first, prepare the flange 20, reserve the prestressed tendon channel 25 on the flange 20, and preset the vertical steel bars 10 on the flange 20, and the vertical steel bars 10 and the flange 20 are a whole. Then, weave the vertical longitudinal bars 6 and the annular stirrups 7 on the flange 20 to form a steel cage, add anchor steel bars 8 at the connection between the vertical longitudinal bars and the annular stirrups, and the anchor steel bars 8 are formed into a whole with the steel cage by binding and welding, and then pour the ordinary concrete 4. After forming, part of the anchor steel bars 8 are exposed on the outer surface of the ordinary concrete 4, forming a "∩" shape. Then pour the outer UHPC shell 5, so that the inner ordinary concrete 4, the outer UHPC shell 5 and the flange 20 form a whole, forming the top concrete cylinder section 11, the middle concrete cylinder section 12, and the bottom concrete cylinder section 13. The manufacturing method of the concrete cylinder sections 3 at other positions is the same, the difference is that the flange 20 is not added. The tower consists of an upper pure steel tower 1 and a lower concrete tower 2. The concrete tower 2 is a hollow truncated cone and is prefabricated in sections, that is, the tower is divided into several concrete cylinder sections 3 along the height direction. After being prefabricated in the factory, it is assembled on site. When assembling each concrete cylinder section up and down, it is necessary to pay attention to whether the prestressed tendon holes 25 on the flange 20 are aligned so that the prestressed tendons can be tensioned by the post-tensioning method later. The number of prestressed tendon holes in the first flange 21 is equal to that in the fourth flange 24, and the number of prestressed tendon holes in the second flange 22 is equal to that in the third flange 23, and the number is 1.5 times that of the first flange 21. After the assembly is completed, multiple vertical segments are connected by horizontal joint grouting, and pre-pressure is applied by tensioning the full-length prestressed tendons and the segmented prestressed tendons to compress each segment to form an integral tower. A number of high-strength prestressed anchor bolts 30 are arranged on the top surface of the top concrete cylinder section 11 to connect the bottom of the steel tower 1.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit the protection scope of the utility model. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the utility model.

Claims

1. A hybrid wind power tower outsourced with UHPC, characterized in that: The invention comprises a concrete tower (2) in the middle and lower part, wherein a steel tower (1) is fixed on the top of the concrete tower (2), and the bottom is fixed on a foundation (100); the concrete tower (2) is composed of concrete cylinder sections (3) stacked and connected in sequence from bottom to top; wherein the concrete cylinder sections (3) include a top concrete cylinder section (11) at the top, a plurality of middle concrete cylinder sections (12) in the middle, and a bottom concrete cylinder section (13) at the bottom; a first flange (21) is fixed on the top of the top concrete cylinder section (11), a second flange (22) and a third flange (23) are fixed on the top and bottom of the middle concrete cylinder section (12), respectively; and a bottom concrete cylinder section (13) is fixed on the top of the top concrete cylinder section (11). A fourth flange (24) is fixed to the bottom of the cylinder segment (13); a plurality of prestressed tendon holes (25) are evenly arranged on the first flange (21), the second flange (22), the third flange (23) and the fourth flange (24) along the circumferential direction; the full-length prestressed tendons (26) sequentially pass through the first flange (21), the second flange (22), the third flange (23) and the fourth flange (24) to apply prestress to the concrete cylinder segment (3) to form a whole; the outer side of the concrete cylinder segment (3) is a UHPC shell (5) and the inner side is ordinary concrete (4); the UHPC shell (5) and the ordinary concrete (4) are fixedly connected by internally embedded anchor steel bars (8).

2. The hybrid wind turbine tower with outsourced UHPC as claimed in claim 1, characterized in that: The first flange (21), the second flange (22), the third flange (23) and the fourth flange (24) are all fixed with preset vertical steel bars (10), and the preset vertical steel bars (10) are buried in ordinary concrete (4).

3. The hybrid wind turbine tower with outsourced UHPC as claimed in claim 2, characterized in that: A steel cage is embedded in the ordinary concrete (4), and preset vertical steel bars (10) extend into the steel cage.

4. The hybrid wind turbine tower with outsourced UHPC as claimed in claim 3, characterized in that: The steel cage comprises a plurality of vertical longitudinal bars (6) arranged along the circumference of the concrete cylinder section (3), and a plurality of circumferential stirrups (7) are bundled around the outer circumference of the vertical longitudinal bars (6); and anchoring steel bars (8) are fixed on the steel cage.

5. The hybrid wind turbine tower with outsourced UHPC as claimed in claim 1, characterized in that: The anchoring steel bar (8) is oval in shape and is exposed outside the ordinary concrete (4) to form a "∩"-shaped structure.

6. The hybrid wind turbine tower with outsourced UHPC as claimed in claim 1, characterized in that: A plurality of prestressed anchor bolts (30) are arranged along the circumferential direction on the top of the first flange (21), and the prestressed anchor bolts (30) are fixedly connected to the steel tower (1).

7. The hybrid wind turbine tower with outsourced UHPC as claimed in claim 1, characterized in that: The number of the prestressed tendon holes (25) on the second flange (22) and the third flange (23) is 1.5 times the number of the prestressed tendon holes (25) on the first flange (21) and the fourth flange (24); the prestressed tendon holes (25) of the second flange (22) and the third flange (23) are also penetrated by segmented prestressed tendons, and the segmented prestressed tendons include upper segmented prestressed tendons (27) and lower segmented prestressed tendons (28); the top end of the upper segmented prestressed tendons (27) is anchored to the first flange ( The lower end of the prestressed tendon (28) passes through the prestressed tendon hole (25) of the fourth flange (24) and is anchored on the foundation (100), and the top end passes through the third flange (23) and the second flange (22) in sequence and is anchored on the top surface of the second flange (22) of the middle concrete cylinder section (12) at the middle.

8. The hybrid wind turbine tower with outsourced UHPC as claimed in claim 7, characterized in that: The segmented prestressed tendons and the full-length prestressed tendons (26) are arranged alternately.

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