Bracing structure for onshore wind turbine support

Abstract

To provide a brace structure of an onshore wind turbine support capable of increasing the size and height of an onshore wind power generation device without increasing the diameter of a tower.SOLUTION: This foundation structure has a foundation part 2 supported by the ground, a tower 3 supported by the foundation part 2, and a brace 4 for joining the foundation part 2 and the tower 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a brace structure for an onshore wind turbine support. [Background technology]

[0002] Onshore wind power generation equipment is becoming larger and taller in anticipation of increased power generation. However, in recent years, due to the limited capacity of erection cranes (1,200-ton all-terrain cranes) and transportation restrictions imposed by road construction limits, the size and height of onshore wind power generation equipment has nearly reached its limit. For this reason, the applicant has developed an onshore wind turbine support structure that allows the construction of larger and taller onshore wind power generation equipment without the need for a 1,200-ton all-terrain crane (see, for example, Patent Document 1). Onshore wind turbine support refers to the tower and foundation that support the wind turbine and generator of an onshore wind power generation equipment. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-152120 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, the taller an onshore wind turbine is, the greater the moment that occurs at the bottom of the tower. To withstand this large moment, the tower must be made larger in diameter. Because there is no way to transport a large-diameter tower, several methods have been proposed in which a large-diameter tower is manufactured in multiple sections and the sections are joined on-site. However, in Japan, the hurdles to obtaining design certification, including for the joint between the tower and foundation, are high, and none of these methods have yet achieved design certification.

[0005] Therefore, an object of the present invention is to provide a brace structure for an onshore wind turbine support that enables onshore wind power generation equipment to be made larger and taller without the need to make the tower larger in diameter. [Means for solving the problem]

[0006] In order to achieve the above object, the brace structure of an onshore wind turbine support according to the present invention comprises a foundation supported by the ground, a tower supported by the foundation, and a brace connecting the foundation and the tower.

[0007] In the present invention, braces are provided around the tower to connect the foundation and the tower, so that the load concentrated at the lower end of the tower can be borne not only by the tower but also by the braces, and can also be transmitted from the braces to the foundation. As a result, the present invention allows for a smaller tower diameter than conventional onshore wind turbine support structures that support the wind turbine only by the tower without using braces. The present invention allows for larger and taller onshore wind turbines without the need for a larger tower diameter. Even if an onshore wind turbine is equipped with a generator larger than conventional, the present invention allows for a smaller tower diameter than conventional by providing braces around the tower to connect the foundation and the tower.

[0008] In the brace structure of an onshore wind turbine support according to the present invention, the foundation comprises a tower foundation on which the tower is erected and a brace foundation to which the brace is joined, and the tower foundation and the brace foundation may be integrally formed.

[0009] By adopting such a configuration, the base portion can be made into a strong structure.

[0010] In the brace structure of an onshore wind turbine support according to the present invention, the foundation comprises a tower foundation on which the tower is erected and a brace foundation to which the brace is joined, and the tower foundation and the brace foundation may be provided separately.

[0011] By adopting this configuration, the amount of concrete and reinforcing bars in the foundation can be reduced compared to when the tower foundation and the brace foundation are integrated. [Effects of the Invention]

[0012] According to the present invention, it is possible to increase the size and height of an onshore wind turbine generator without the need to increase the diameter of the tower. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, showing the lower side of the onshore wind turbine generator according to the first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 3] FIG. 5 is a cross-sectional view taken along line CC in FIG. 4, showing the lower side of the onshore wind turbine generator according to the second embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line DD in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0014] (First embodiment) Hereinafter, a brace structure for an onshore wind turbine support according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. As shown in Figures 1 and 2, the onshore wind turbine generator 1 according to this embodiment has a foundation 2, a tower 3, a brace 4, a wind turbine (not shown), and a generator (not shown). The foundation 2 is supported by the ground G. The tower 3 is supported by the foundation 2. The lower end of the tower 3 is connected to the foundation 2. The wind turbine and generator are attached to the upper end of the tower 3. The wind turbine has multiple blades, and the rotational force of the blades rotated by wind is input to the generator. The brace 4 joins the foundation 2 to the middle part of the tower 3 in the height direction. The foundation 2, tower 3, and brace 4 are collectively referred to as an onshore wind turbine support 5. The brace structure of the onshore wind turbine support 5 is a structure of the onshore wind turbine support 5 to which the brace 4 is attached.

[0015] The foundation 2 has a regular octagonal shape in plan view from the top and bottom. The top surface 21 of the foundation 2 is flat all over and is at approximately the same height as the ground surface. The foundation 2 is made of reinforced concrete. The tower 3 is cylindrical. The tower 3 is made of steel.

[0016] The brace 4 is a steel brace extending linearly. Four braces 4 are provided around the tower 3 at 90° intervals in the circumferential direction. One longitudinal end 41 of each brace 4 is pin-connected to the top surface 21 of the foundation 2 at a position spaced from the tower 3. The other longitudinal end 42 of each brace 4 is pin-connected to the outer circumferential surface of the tower 3 at a midpoint in the height direction. The other end 42 of each brace 4 is pin-connected to the tower 3 at a height position approximately 20 to 40 meters above the top surface 21 of the foundation 2. The brace 4 gradually slopes upward from the bottom toward the axis of the tower 3. In this embodiment, the angle between the brace 4 and the top surface 21 of the foundation 2 is approximately 45 to 75 degrees.

[0017] Next, the operation and effect of the brace structure of the onshore wind turbine support 5 according to this embodiment will be described. In the brace structure of the onshore wind turbine support 5 according to this embodiment, braces 4 are provided around the tower 3, joining the foundation 2 and the tower 3, so that the load concentrated at the bottom end of the tower 3 can be borne not only by the tower 3 but also by the braces 4, and can also be transmitted from the braces 4 to the foundation 2. As a result, the brace structure of the onshore wind turbine support 5 according to this embodiment allows the diameter of the tower 3 to be smaller than in conventional onshore wind turbine support structures in which the wind turbine and generator are supported only by the tower. In this embodiment, the onshore wind turbine generator 1 can be made larger and taller without the need to make the tower 3 larger in diameter.

[0018] Even if the onshore wind turbine power generation device 1 is made larger and taller, the diameter of the tower 3 does not increase, so the tower 3 can be transported using conventional transportation methods during construction. In other words, even if there are transportation restrictions, an onshore wind turbine power generation device 1 with a higher power generation capacity can be constructed. By transporting the braces 4 and tower 3 in an unconnected state and then connecting them on site, it is possible to reduce the size of the transportation vehicle compared to when the braces 4 and tower 3 are connected before transporting. By making the braces 4 in a form that can be installed on site using a small general-purpose crane, it is possible to reduce construction costs. Since the braces 4 are provided around the tower 3, the wind load acting on the tower 3 can be reduced compared to when the tower is made larger in diameter. In this embodiment, even if a larger generator than conventional is installed in the onshore wind power generation device 1, it is possible to make the diameter of the tower 3 smaller than conventional by installing braces 4 around the tower 3 to connect the foundation 2 and the tower 3.

[0019] The portion of the foundation 2 that supports the lower end of the tower 3 is referred to as the tower foundation 22, and the portion to which the other end 42 of the brace 4 is joined is referred to as the brace foundation 23. The tower foundation 22 and the brace foundation 23 are provided integrally. This configuration allows the foundation 2 to have a strong structure.

[0020] (Second embodiment) Next, a second embodiment will be described. The same or similar members and parts as those in the first embodiment will be denoted by the same reference numerals, and the description will be omitted. Only the configurations different from the first embodiment will be described. As shown in Figures 3 and 4, the foundation 2B of the onshore wind power generation apparatus 1B according to the second embodiment includes a tower foundation 22B that supports the lower end of the tower 3 and a brace foundation 23B to which the other end 42 of the brace 4 is joined. Four brace foundations 23B are provided around the tower foundation 22B at 90° intervals in the circumferential direction. The tower foundation 22B and the four brace foundations 23B are not integrated but are provided separately. The tower foundation 22B and the brace foundations 23B both have a square shape in a plan view when viewed from the top and bottom. In the second embodiment, the foundation 2B, the tower 3, and the brace 4 are collectively referred to as an onshore wind turbine support 5B. The brace structure of the onshore wind turbine support 5B refers to the structure of the onshore wind turbine support 5B to which the brace 4 is provided.

[0021] The brace structure of the onshore wind turbine support 5B according to the second embodiment has the same effects as the brace structure of the onshore wind turbine support 5 according to the first embodiment. The brace structure of the onshore wind turbine support 5B according to the second embodiment can reduce the amount of concrete and reinforcing bars in the foundation 2B.

[0022] The above describes an embodiment of the brace structure for an onshore wind turbine support according to the present invention, but the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, four braces 4 are provided around the periphery of the tower 3, but the number of braces provided around the periphery of the tower 3 may be set appropriately. The braces 4 may be other than steel braces. For example, they may be steel pipe braces. They may also be clevis pipes, which are steel pipes with a clevis at the end. The height at which the braces 4 are joined to the tower 3, the inclination angle of the braces 4 relative to the foundation 2 and the tower 3, and the like may be set as appropriate. The joining structure between the braces 4 and the foundation 2 and the joining structure between the braces 4 and the tower 3 may be set as appropriate, for example, by a rigid joint. The height at which the braces 4 are joined to the tower 3 may be set as appropriate.

[0023] The shape of the base portions 2, 2B may be set as appropriate. For example, the planar shape of the base portions 2, 2B may be a regular octagon, a square, a circle, or the like. In the second embodiment, a plurality of braces 4 may be attached to one brace base portion 23B. The shape of the tower 3 may be set appropriately.

[0024] The Sustainable Development Goals (SDGs) are 17 international goals adopted at the United Nations Summit in September 2015. The brace structure of the onshore wind turbine support in this embodiment can contribute to achieving one of the 17 SDGs, for example, goal 9, "Create indispensable infrastructure for industry, innovation and sustainable development." [Explanation of symbols]

[0025] 1,1B Onshore wind power generation equipment 2,2B Foundation part 3. Tower 4 braces 5,5B Onshore wind turbine support 22,22B Tower base 23,23B Brace base G Ground

Claims

1. A foundation supported by the ground; a tower supported on the foundation; and a brace connecting the foundation and the tower.

2. The base portion is a tower base on which the tower is built; a brace base portion to which the brace is joined, The brace structure for an onshore wind turbine support according to claim 1 , wherein the tower foundation and the brace foundation are integrally formed.

3. The base portion is a tower base on which the tower is built; a brace base portion to which the brace is joined, The brace structure for an onshore wind turbine support according to claim 1 , wherein the tower foundation and the brace foundation are provided separately.

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