Tower transition tower section, tower and wind turbine generator set

Abstract

The present invention discloses a tower transition tower section, a tower and a wind turbine generator set. The transition tower section is composed of a plurality of incomplete conical shells connected to each other. The incomplete conical shell includes a large end and a small end, the large end is a non-closed arc segment, the large end arc segment is a complete plane circular ring, and the plane circular ring constitutes the top of the transition tower section; the small end end face is a complete circular ring, and the small end end face is connected to the lattice tower of the wind turbine set. The part of the incomplete conical shell near the small end is a continuous closed curved surface. All convex surfaces of the incomplete conical shells are arranged to the outside of the transition tower section, and a part of the side edges of the incomplete conical shells near the large end are provided with connecting sections connected to adjacent incomplete conical shells. The incomplete conical shells are rolled from metal sheets, which is convenient for manufacturing and transportation. Compared with the current technology, the transition tower section has good rigidity and stronger bearing capacity, and the bending and torsional resistance of the structure are maximized, which better realizes the transition from cylindrical tower to lattice tower.

Description

Technical Field

[0001] The invention belongs to the technical field of wind power generation, and in particular relates to a tower transition tower section, a tower and a wind power generator set. Background Art

[0002] Wind power is the most promising power generation method in the renewable energy field with the greatest large-scale development value and commercial development prospects. Available wind energy is widely distributed around the world and has huge reserves.

[0003] Wind turbines use blades to convert the kinetic energy of air molecules into mechanical energy, ultimately generating electricity. Due to the influence of surface roughness, vertical wind shear characteristics vary across different regions. Vertical wind shear refers to the phenomenon in which the wind vector (including wind speed and direction) changes with altitude above the ground. Generally, wind speed increases with altitude. This explains why wind turbine hub heights are high, and not just to prevent blade tips from contacting the ground. A higher hub height allows the turbine to achieve higher wind speeds, which translates to higher power generation returns. Therefore, in addition to larger capacity (increased unit capacity) and longer blades, another major development characteristic of modern wind turbines is the increasing hub height. This increased hub height inevitably requires a higher tower height, and a major challenge facing the wind power industry is ensuring the economic viability of tall towers.

[0004] Wind turbine towers are inherently tall structures, and increasing their height is not inherently technically challenging. The real technical challenge lies in increasing tower height while ensuring safety and reliability while also controlling material, manufacturing, transportation, and installation costs. As power-generating equipment, wind turbines are inherently different from towering structures in the construction industry; they must prioritize cost-effectiveness. Simply piling materials together is doomed to fail. Currently, steel-concrete tower technology is a hot topic in the wind power industry. A steel-concrete tower utilizes a conventional steel cylindrical section for the nacelle connection, with concrete framing as much of the structure below as possible. The low cost of concrete makes the steel-concrete tower significantly more economical. However, the long-term, continuous, and irregular operation of wind turbines necessitates consideration of the tower's fatigue life. Concrete's fatigue resistance is far inferior to that of metal. Consequently, steel-concrete towers can suffer irreversible fatigue damage over time, posing reliability and safety risks.

[0005] Another high tower technology is the modular tower. The part connected to the wind turbine nacelle uses a conventional steel cylindrical tower, and the lattice tower is used below the steel cylindrical tower. Since the lattice tower uses less steel, the modular tower also has an economic advantage. However, the modular tower needs to solve the connection problem between the steel cylindrical tower and the lattice tower. In the aforementioned steel-concrete tower, the materials of the steel cylindrical tower and the concrete tower are continuously distributed, so the transition from the steel cylindrical tower to the concrete tower can be achieved by bolting and other methods. In contrast, in the modular tower, the materials of the lattice tower are discretely distributed, which makes the transition from the steel cylindrical tower to the lattice tower a technical challenge faced by the industry. Simple direct connection will cause sudden changes in structural stiffness and stress concentration at the connection. In actual wind turbine operation, excessive structural deformation may cause tower failure.

[0006] New technologies currently being proposed for connecting steel cylindrical towers to lattice towers have, to some extent, addressed the structural transition issue. However, the transition section requires a significant amount of structural material, resulting in large structural dimensions and high transportation costs, sometimes even prohibiting normal transport. Therefore, how to connect steel cylindrical towers to lattice towers while maintaining the tower's load-bearing capacity and improving the structure's economic efficiency remains a technical challenge facing the industry. Summary of the Invention

[0007] In order to solve at least one of the above technical problems, a first aspect provides a tower transition tower section, characterized in that the top of the transition tower section is connected to the bottom flange of the cylindrical tower or the circular flange of the base or the yaw slewing bearing flange of the wind turbine; the transition tower section is composed of at least three incomplete conical shells connected to each other;

[0008] The incomplete conical shell comprises a large end and a small end; the large end is a non-closed arc segment, and all the arc segments of the large end of the incomplete conical shell are arranged to form a complete plane circular ring, and the plane circular ring constitutes the top of the transition tower section;

[0009] The end surface of the small end is a complete circular ring, and the end surface of the small end is connected to the lattice tower of the wind turbine generator set;

[0010] The portion of the incomplete conical shell close to the small end is a continuous closed curved surface;

[0011] All of the incomplete conical shell convex surfaces are arranged toward the outside of the transition tower section;

[0012] A portion of the side edges of the incomplete conical shell close to the large end are provided with connecting sections connected to adjacent incomplete conical shells.

[0013] In a further technical solution, the large end arc segment is provided with a flange segment, and all of the flange segments constitute a complete top flange of the transition tower section.

[0014] In a further technical solution, the top flange surface of the transition tower section is connected to the bottom flange of the cylindrical tower or the circular flange of the base or the yaw slewing bearing flange directly or through an additional flange.

[0015] The incomplete conical shell is formed by rolling a polygonal plate. The portion of the incomplete conical shell close to the small end is a closed curved surface, and the remaining portion is a non-closed curved surface.

[0016] The connecting section of the incomplete conical shell is provided with a longitudinal flange for connection with the adjacent incomplete conical shell.

[0017] The inner surface of the incomplete conical shell is a concave surface, which is located inside the transition tower section. Reinforcement ribs are provided on the inner surface of the incomplete conical shell.

[0018] The small end is connected to the main chord at the top of the lattice tower, and the number of the incomplete conical shells is the same as the number of the main chord of the lattice tower.

[0019] In a further technical solution, the small end face is provided with a flange, which is docked with the top end face flange of the main chord, and the small end face is perpendicular to the central axis of the main chord.

[0020] In a second aspect, a tower is provided, comprising the tower transition tower section.

[0021] According to a third aspect, a wind turbine generator set is provided, wherein the wind turbine generator set includes the tower described above.

[0022] The present invention provides the following advantages: the tower transition section is constructed by splicing together multiple incomplete conical shells. The incomplete conical shells are rolled from metal sheets, making them easy to manufacture. Furthermore, the incomplete conical shells are easy to transport, eliminating the problem of oversized transportation. Compared to existing technologies, the tower transition section offers superior rigidity and load-bearing capacity, maximizing the structure's bending and torsional resistance, and better facilitating the transition from steel cylindrical towers to lattice towers. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the load deformation of the conventional tower transition technology solution;

[0024] Figure 2 This is a schematic diagram of a tower transition section connection according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the composition of a tower transition section according to an embodiment of the present invention;

[0026] Figure 4 This is an axonometric view of a tower transition section according to an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of an incompletely tapered shell shaft end portion of a tower transition section according to an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the connection between a tower transition section and a lattice tower main chord according to an embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of an incomplete tapered shell-shaft connection interface of a tower transition section according to an embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram of the top of a tower transition section according to an embodiment of the present invention;

[0031] Figure 9 This is a schematic diagram of the bottom of a tower transition tower section according to an embodiment of the present invention.

[0032] Description of Figure Numbers:

[0033] 1. Transition tower section, 1.1. Incomplete conical shell, 1.101. Big end, 1.102. Small end, 1.103. Side of incomplete conical shell, 1.104. Flange section of big end of incomplete conical shell, 1.105. Longitudinal flange at top of incomplete conical shell, 1.106. Internal reinforcement ribs of incomplete conical shell, 1.107. Flange of small end of incomplete conical shell, 2. Cylindrical tower, 3. Lattice tower, 3.1. Main chord.

[0034] It is important to note that the figures above are intended to illustrate features of the present invention and are not intended to depict any actual structure or reflect detailed information such as the dimensions and relative proportions of various components. To more clearly demonstrate the principles of the present invention and to avoid obscuring the principles of the present invention with unnecessary detail, the examples in the figures have been simplified. These illustrations will not cause difficulty for those skilled in the relevant art in understanding this patent, and actual embodiments may include more modules or components. DETAILED DESCRIPTION

[0035] To make the purpose and technical solution of the embodiments of the present invention clearer, the embodiments of the present invention are fully described below in conjunction with the relevant drawings of the embodiments of the present invention. This patent describes only some embodiments, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] 1. Technical problems in the current transition from steel cylindrical towers to lattice towers

[0037] Modern wind turbine blades are longer. As blades lengthen, they become more flexible, leading to more pronounced deformation under load. To ensure blade clearance—the safe distance between the blades and the tower—the length of the steel cylindrical tower in a modular tower is typically close to the blade length. This is because increasing the lattice tower's bending resistance requires a significant increase in its cross-sectional area. Excessive cross-sectional area reduces the safe distance from the blades. Therefore, the lattice tower in a modular tower is typically located below the blade tip. This configuration places stringent demands on the connection between the steel cylindrical tower and the lattice tower: the height of the steel cylindrical tower from the rotor (approximately the length of the blade) results in a very large bending moment at the base of the steel cylindrical tower. Therefore, the connection between the steel cylindrical tower and the lattice tower (or the transition from the steel cylindrical tower to the lattice tower) must be highly resistant to bending.

[0038] Lattice towers are primarily composed of main chords and web members. They are economical but weak in torsional resistance, and require a relatively large cross-sectional area (compared to steel cylindrical towers) to achieve sufficient bending resistance. Furthermore, the discrete arrangement of materials in a lattice tower, with the main chord and several web members acting as a finite number of load transfer paths, means that loads are transferred discretely. Therefore, the transition from a steel cylindrical tower to a lattice tower presents two technical challenges: 1) How to smoothly transition from the smaller cross-section of the steel cylindrical tower at the base to the larger cross-section of the lattice tower at the top; and 2) How to smoothly transition from a steel cylindrical tower with continuous material distribution and continuous load transfer to a lattice tower with discrete material distribution and discrete load transfer. These challenges are not simply about "transition," but also about ensuring a "smooth" transition. Any abrupt transition will compromise the continuity of the structure and cause load-bearing capacity issues, such as stress concentration caused by sudden changes in stiffness.

[0039] The fixed foundation of offshore wind power also includes the transition from steel cylindrical tower to lattice tower, but onshore wind turbines cannot directly refer to the technical solutions of offshore wind power fixed foundation, and it has been proven to be wrong: a domestic 7MW wind turbine uses a combined tower. In the transition solution from steel cylindrical tower to lattice tower, the main chord is directly connected to the side or bottom of the steel cylindrical tower. Since the number of main chords is limited, the load transmission path is limited, resulting in a sudden change in structural stiffness. The transition section does not complete a "smooth" transition, resulting in a sudden change in structural stiffness. In addition, the transition section's own bending resistance is poor, resulting in discontinuous deformation of the combined tower after the wind turbine is loaded, and a sudden change occurs in the transition section (such as Figure 1 As shown in the figure, in order to show the deformation effect more clearly, Figure 1 (The image above is exaggerated to some extent). This discontinuous deformation may cause additional bending moments, which will further affect the already weak transition section. In addition, this discontinuous deformation of the tower will also have a negative impact on the clearance of the blades.

[0040] 2. Concept of this patent

[0041] The core technical features of the transition tower section proposed in this patent can be summarized as follows:

[0042] 1) The transition tower section consists of at least three interconnected incomplete conical shells. Each incomplete conical shell has a large end and a small end. The large end is a non-closed arc segment. The large end arc segments of all incomplete conical shells are configured as a complete flat ring, which can be directly connected to the steel cylindrical tower.

[0043] 2) The small end of the conical shell is a complete circular ring, which is connected to the lattice tower of the wind turbine. The transition tower section realizes the transition from the complete circle (continuous) of the steel cylindrical tower to the multiple circular tubes (discrete) of the lattice tower.

[0044] 2) The portion of the incomplete conical shell close to the small end is a continuous closed curved surface, and the convex surfaces of the incomplete conical shell are all arranged toward the outside of the transition tower section.

[0045] These technical features not only meet the requirements for transitioning from a small to a large cross-sectional area from a steel cylindrical tower to a lattice tower, but also ensure that the transition structure maintains the curved form of the steel cylindrical tower, achieving a more natural and continuous transition. Furthermore, the incompletely tapered shell in the transition tower section offers greater stiffness than the flat plate structures used in existing solutions.

[0046] 3. An embodiment of a tower transition section

[0047] like Figure 2 As shown, the top of the transition tower section (1) is connected to the flange at the bottom of the cylindrical tower (2) of the wind turbine. In other embodiments, the top of the transition tower section (1) may also be connected to the circular flange of the wind turbine base or the yaw slewing bearing flange. In other words, the transition tower section (1) is also suitable for the transition from the wind turbine nacelle directly to the lattice tower (3), and is not limited to the transition from the cylindrical tower (2) to the lattice tower (3) in the modular tower.

[0048] The transition tower section (1) is composed of at least three incomplete conical shells connected to each other, such as Figure 3 As shown, the transition tower section (1) in this embodiment is composed of four incomplete conical shells (1.1) connected to each other.

[0049] As shown in Figure 4, similar to the tower section of the cylindrical tower (2), the incomplete conical shell of the transition tower section (1) can be formed by rolling a plate, and the incomplete conical shell (1.1) includes a large end (1.101) and a small end (1.102). Figure 5As shown, the portion close to the small end (1.102) is a continuous closed surface, and the remaining portion is a non-closed surface. The large end (1.101) of the incomplete conical shell is a non-closed arc segment. In this embodiment, all four arc segments of the large end (1.101) of the incomplete conical shell can be spliced ​​together to form a complete flat circular ring. It should be noted that after the incomplete conical shell (1.1) is formed by rolling the sheet, its large end (1.101), small end (1.102) and side (1.103) parts need further processing. Otherwise, if multiple arc segments of the large end (1.101) of the incomplete conical shell are directly spliced ​​together, what is formed is not the "complete flat circular ring" mentioned above, but a "complete conical surface circular ring". The "plane" in the flat circular ring is an important feature, and the flat circular ring constitutes the top of the transition tower section (1).

[0050] Similar to the above-mentioned plane ring, the end face of the small end (1.102) of the incomplete conical shell is a complete ring, which also needs to be processed. Figure 2 、 Figure 3 and Figure 6 As shown, the end face of the small end (1.102) is connected to the lattice tower (3) of the wind turbine generator set, completing the transition function of the transition tower section (1).

[0051] All the convex surfaces of the incomplete conical shells are arranged to face the outside of the transition tower section (1). This arrangement makes it possible for the outer surface of the entire transition tower section (1) (at least in a section near the top) to be very close to the steel cylindrical tower (2) after the multiple incomplete conical shells (1.1) are connected to form the transition tower section (1). This arrangement also makes the transition from the cylindrical tower (2) to the lattice tower (3) in the combined tower frame reflect the characteristics of a natural transition in terms of geometric appearance alone (such as Figure 2 shown).

[0052] like Figure 7 As shown, the two sides (1.103) of the incomplete conical shell near the large end (1.101) are provided with a connecting section connected to the adjacent incomplete conical shell. In some embodiments, starting from the end of the connecting section to the small end (1.102) of the incomplete conical shell, the two adjacent incomplete conical shells (1.1) may not be directly connected. However, in this embodiment, a rod is used for connection (such as Figure 8 shown), it all depends on the structural requirements.

[0053] The novelties and advantages of the above technical solution are:

[0054] The transition tower section (1) is composed of a plurality of incomplete conical shells (1.1) connected together. The large end (1.101) of the incomplete conical shell is a non-closed arc segment, and the multiple arc segments can be assembled into a complete flat circular ring; the small end (1.102) is a continuous closed curved surface, and the end face of the small end (1.102) is a complete circular ring. The flat circular ring of the transition tower section (1) can be connected to the bottom of the cylindrical tower (2), and the end face of the small end (1.102) can be connected to the rod of the lattice tower (3). The transition tower section (1) can be spliced ​​at the installation site, which is very convenient for transportation and installation.

[0055] The incomplete conical shell can be formed by rolling sheet metal, which is low-cost and convenient to process. Compared with the flat sheet metal used in existing solutions, the incomplete conical shell has better inherent rigidity. Under the same structural rigidity conditions, the material cost of this solution is lower.

[0056] The convex surfaces of the incomplete conical shells are all arranged outside the transition tower section (1), and the two sides (1.103) of the incomplete conical shells near the large end (1.101) are provided with connecting sections connected to the adjacent incomplete conical shells. In terms of geometric shape transition and material distribution transition, the transition tower section (1) has achieved a natural transition from a small cross section to a large cross section, and from continuous load transfer to discrete load transfer. Compared with the existing transition scheme, the structure is more reasonable, and the material in the transition tower section (1) is distributed as much as possible like the outside (such as Figure 2 and Figure 3 As shown), the bending and torsional resistance of the transition tower section (1) is maximized.

[0057] like Figure 8 As shown, the arc section of the large end (1.101) of the incomplete conical shell is provided with a flange section (1.104). Similar to the case of the aforementioned flat circular ring, all the flange sections (1.104) constitute the complete top flange of the transition tower section (1). The top flange surface of the transition tower section (1) is directly or through an additional flange plate connected to the bottom flange or the base circular flange or the yaw slewing bearing flange of the cylindrical tower (2).

[0058] When forming the transition tower section (1), if Figure 7 and 9 As shown, the connecting section of the incomplete conical shell is provided with a longitudinal flange (1.105) for connecting with the adjacent incomplete conical shell. The longitudinal flange (1.105) can be selected as an L-shaped flange or a T-shaped flange according to actual application requirements.

[0059] like Figure 6 and Figure 9The inner surface of the incomplete conical shell is concave and is located inside the transition tower section (1). The inner surface of the incomplete conical shell is provided with reinforcing ribs (1.106). When a plurality of incomplete conical shells are spliced ​​together to form the transition tower section (1), it is equivalent to providing reinforcing ribs inside the transition tower section (1).

[0060] like Figure 2 、 Figure 3 and Figure 6 As shown, the small end (1.102) of the incomplete conical shell is connected to the main chord (3.1) at the top of the lattice tower (3). Therefore, the number of incomplete conical shells is the same as the number of tower main chords (3.1). The number of main chords (3.1) of the lattice tower (3) and the number of incomplete conical shells (1.1) should be determined by the design requirements of the actual wind turbine. However, it can at least be determined that the lattice tower contains at least three main chords (including two main chords that are plane trusses and cannot be used as towers in actual applications), which is consistent with the constraint on the number of incomplete conical shells in this solution.

[0061] The end face of the small end (1.102) of the incomplete conical shell is provided with a small end flange (1.107) which is butted against the top end face flange of the main chord (3.1), and the end face of the small end (1.102) is perpendicular to the central axis of the main chord (3.1).

[0062] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "up, down, front, back, left and right" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0063] In this disclosure, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they may refer to fixed, removable, or integral connections. They may also refer to mechanical, electrical, or direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure.

[0064] While the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and equivalent components may be substituted without departing from the scope of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner, provided no structural conflicts exist. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A tower transition tower section, characterized in that: The top of the transition tower section (1) is connected to the bottom flange of the cylindrical tower (2) of the wind turbine generator set, or the circular flange of the base, or the yaw slewing bearing flange; the transition tower section (1) is composed of at least three incomplete conical shells connected to each other; The incomplete conical shell (1.1) comprises a large end (1.101) and a small end (1.102); the large end (1.101) is a non-closed arc segment, and all the arc segments of the large end (1.101) of the incomplete conical shell are arranged to form a complete plane circular ring, and the plane circular ring constitutes the top of the transition tower section (1); The end surface of the small end (1.102) is a complete circular ring, and the end surface of the small end (1.102) is connected to the lattice tower (3) of the wind turbine generator set; The portion of the incomplete conical shell (1.1) close to the small end (1.102) is a continuous closed curved surface; All convex surfaces of the incomplete conical shell (1.1) are arranged toward the outside of the transition tower section (1); A portion of the side edge (1.103) of the incomplete conical shell (1.1) close to the large end (1.101) is provided with a connecting section connected to an adjacent incomplete conical shell (1.1).

2. A tower transition section according to claim 1, characterized in that: The large end (1.101) arc section is provided with a flange section (1.104), and all the flange sections (1.104) constitute a complete top flange of the transition tower section (1).

3. A tower transition tower section according to claim 2, wherein the top flange surface of the transition tower section (1) is connected to the bottom flange or the base circular flange or the yaw slewing bearing flange of the cylindrical tower (2) directly or through an additional flange plate.

4. A tower transition tower section according to claim 1, wherein the incomplete conical shell (1.1) is formed by rolling a polygonal plate, the portion of the incomplete conical shell (1.1) close to the small end (1.102) is a closed curved surface, and the remaining portion is a non-closed curved surface.

5. A tower transition tower section according to claim 1, wherein the connecting section of the incomplete conical shell (1.1) is provided with a longitudinal flange (1.105) for connection with an adjacent incomplete conical shell (1.1).

6. A tower transition tower section according to claim 1, wherein the inner surface of the incomplete conical shell (1.1) is concave and is located inside the transition tower section (1), and reinforcing ribs (1.106) are provided on the inner surface of the incomplete conical shell (1.1).

7. A tower transition tower section according to claim 1, wherein the small end (1.102) is connected to the main chord (3.1) at the top of the lattice tower (3), and the number of the incomplete conical shells (1.1) is the same as the number of the main chords (3.1) of the lattice tower (3).

8. A tower transition tower section according to claim 7, wherein the end face of the small end (1.102) is provided with a small end flange (1.107), which is butted against the top end face flange of the main chord (3.1), and the end face of the small end (1.102) is perpendicular to the central axis of the main chord (3.1).

9. A tower, characterized in that: It comprises a tower transition tower section as described in any one of claims 1-8.

10. A wind turbine generator set, characterized in that: A tower comprising the tower described in claim 9.

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