Wind power generation support body and method for constructing wind power generation support body

Abstract

To provide a wind power generation support body which can be constructed regardless of an outer diameter of the wind power generation support body, and a construction method of the wind power generation support body.SOLUTION: The upper support 3 includes a tubular main body portion 31 disposed on the lower support 2, and a tubular skirt portion 4 coaxially joined to an outer periphery of the main body portion 31 and protruding downward from the main body portion 31, an upper end portion of the lower support 2 is inserted into an inside of the skirt portion 4, and an upper end of the lower support 2 and a lower end of the main body portion 31 are welded to each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a wind turbine support and a method for constructing the wind turbine support. [Background technology]

[0002] Wind turbines are equipped with support structures such as towers and foundations that support the wind turbine and generator. The tower and foundation of the wind turbine support are joined using flange-bolt joints, which connect flanges together with bolts. Offshore wind power generation equipment is provided with wind power generation supports such as monopiles that penetrate the ground and transition pieces that connect the monopiles to the tower (see, for example, Patent Document 1). To connect the monopiles and transition pieces in the wind power generation support, a grout joint is used in which grout is filled between the monopile and the transition piece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-179113 Summary of the Invention [Problem to be solved by the invention]

[0004] When using flange and bolt connections to join wind turbine supports, it is necessary to use large flanges and large-diameter bolts that are certified by the Ministry of Economy, Trade and Industry or the Ministry of Land, Infrastructure, Transport and Tourism. These certified products have size limitations. For example, the maximum outer diameter of a flange is 8m. In recent years, offshore wind power generation equipment has become extremely large and the planned sites have become much deeper, so the outer diameter of the monopile can sometimes be around 10m, which means that certified flanges and bolts may not be usable.

[0005] On the other hand, even if the outer diameter of the monopile exceeds 8m, it is possible to use a grout joint between the monopile and the transition piece. However, when a grout joint is used, the joint between the monopile and the transition piece becomes longer, which increases the weight of the steel material and requires the use of expensive special grout. When wind turbine supports support ultra-large wind turbines, conventional design regulations and standards do not apply. Therefore, when flange bolt joints or grout joints are used to connect wind turbine supports supporting ultra-large wind turbines, special analysis and testing may be required. Furthermore, there are problems such as long construction times and high costs.

[0006] Therefore, an object of the present invention is to provide a wind turbine support and a wind turbine support construction method that can be constructed regardless of the outer diameter of the wind turbine support. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the wind power generation support of the present invention comprises a cylindrical lower support and a cylindrical upper support that is arranged coaxially on the lower support and welded to the lower support, the upper support having a cylindrical main body portion that is arranged on the lower support and a cylindrical skirt portion that is coaxially joined to the outer periphery of the main body portion and protrudes downwardly beyond the main body portion, the upper end portion of the lower support is inserted inside the skirt portion, and the upper end of the lower support and the lower end of the main body portion are welded.

[0008] In order to achieve the above-mentioned object, the construction method of the wind power generation support of the present invention comprises a lower support installation step of installing a cylindrical lower support, an upper support arrangement step of suspending a cylindrical upper support above the lower support and arranging them coaxially, and a welding step of welding the lower support and the upper support together, wherein the upper support has a cylindrical main body portion arranged on the lower support and a cylindrical skirt portion joined coaxially to the outer periphery of the main body portion and protruding downward beyond the main body portion, and in the upper support arrangement step, the upper end portion of the lower support is inserted inside the skirt portion, and in the welding step, the upper end of the lower support is welded to the lower end of the main body portion.

[0009] When a flange is provided between the lower support body and the upper support body and the bolts are connected, it is necessary to use ministerially approved flanges and bolts. The outer diameters of the lower support body and the upper support body must be suitable for the ministerially approved flanges and bolts, which imposes an upper limit on the outer diameters of the lower support body and the upper support body. In contrast, in the present invention, the lower support body and the upper support body are welded together, so the lower support body and the upper support body can be connected regardless of their outer diameters. In addition, costs can be reduced because there is no need to use special components or grout for connections. [Effects of the Invention]

[0010] According to the present invention, construction can be carried out regardless of the outer diameter of the wind turbine support. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating an example of an offshore wind power generation facility according to an embodiment of the present invention. [Figure 2] FIG. 2 is a vertical cross-sectional view of a wind power generation support. [Figure 3] FIG. 2 is an exploded view of the wind power generation support. [Figure 4] FIG. 2 is a diagram showing the groove and root spacing before welding. [Figure 5] FIG. 1 is a diagram showing the groove and root spacing after welding. [Figure 6] FIG. 1 shows a scaffold. [Figure 7] 10A and 10B are diagrams illustrating an upper support arrangement step. [Figure 8] FIG. 10 is a diagram showing work on scaffolding. [Figure 9] FIG. [Figure 10] 10A and 10B are diagrams illustrating position adjustment in an upper support arrangement step. [Figure 11] FIG. 10 is a diagram showing the position of tack welding. [Figure 12] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a wind turbine support and a method for constructing the wind turbine support according to an embodiment of the present invention will be described with reference to FIGS. 1 to 12. FIG. As shown in Fig. 1, the wind power generation support body 1 according to this embodiment is a columnar support body extending in the vertical direction that supports the wind turbines 12, generators, etc. of an offshore wind power generation facility 11. The wind power generation support body 1 has a lower support body 2 and an upper support body 3. The upper support body 3 is joined onto the lower support body 2. The tower 13 of the offshore wind power generation facility 11 is joined onto the upper support body 3. In the construction method of the wind power generation support 1 according to this embodiment, the lower support 2 is installed (lower support installation process), the upper support 3 is lifted and placed above the lower support 2 (upper support placement process), and the lower support 2 and the upper support 3 are welded together (welding process).

[0013] The lower support body 2 is a monopile. The lower side of the lower support body 2 is buried in the ground 14 (seabed) and is supported by the ground 14. The lower support body 2 is a cylindrical steel pipe pile.

[0014] As shown in Figures 2 and 3, the upper support 3 has a main body 31 and a skirt 4. The main body 31 is a transition piece that joins the lower support 2 and the tower 13. The main body 31 is a cylindrical steel pipe. The tower 13 of the offshore wind power generation facility 11 is joined above the main body 31. The main body 31 is arranged coaxially on top of the upper end of the lower support 2, overlapping the upper end surface of the main body 31. The lower end surface of the main body 31 and the upper end of the lower support 2 are welded.

[0015] 4 and 5, in this embodiment, the upper end surface 2a of the lower support body 2 is formed as a flat surface (horizontal surface). The lower end surface 31a of the main body portion 31 of the upper support body 3 is formed as a surface that is gradually inclined upward from the outer side toward the inner side in the radial direction. The angle α of this inclined surface becomes the groove angle α of the welded portion 71.

[0016] The skirt portion 4 is disposed on the outer periphery of the joint between the lower support body 2 and the main body portion 31. The skirt portion 4 is provided to prevent the welding area from being exposed to ocean waves and wind when welding the lower support body 2 and the main body portion 31. The skirt portion 4 is joined to the main body portion 31 in advance, prior to the upper support body arrangement step.

[0017] The skirt portion 4 is cylindrical and is coaxially joined to the lower side of the main body portion 31. The skirt portion 4 is made of steel. The skirt portion 4 has a joining portion 41, a protruding portion 42, and a guide portion 43. The joining portion 41, the protruding portion 42, and the guide portion 43 are each cylindrical and are arranged coaxially from top to bottom in this order.

[0018] The joint portion 41 is disposed on the outer periphery of the lower side of the main body portion 31. The joint portion 41 is joined to the outer peripheral surface 31d of the lower side of the main body portion 31. The lower end of the joint portion 41 is disposed at approximately the same height as the lower end of the main body portion 31.

[0019] The protrusion 42 is disposed below the main body 31 of the upper support 3. The outer diameter of the protrusion 42 is the same as the outer diameter of the joint 41. The outer peripheral surface of the joint 41 and the outer peripheral surface of the protrusion 42 are continuous without any step. The inner diameter of the protrusion 42 is larger than the inner diameter of the joint 41. A step is formed between the lower end of the inner peripheral surface of the joint 41 and the upper end of the inner peripheral surface of the protrusion 42. The step may be tapered. The protrusion 42 is disposed around the upper end portion of the lower support 2. The inner diameter of the protrusion 42 is larger than the outer diameter of the lower support 2. A gap is formed between the inner peripheral surface 42c of the protrusion 42 and the outer peripheral surface 2d of the lower support 2. A sealant 44 is provided at the lower end portion of the inner peripheral surface 42c of the protrusion 42 so as to protrude inward. The sealant 44 is in contact with the outer peripheral surface 2d of the lower support 2.

[0020] The guide portion 43 has a tapered shape with a diameter that gradually increases from the top to the bottom. The upper end of the guide portion 43 is connected to the lower end of the protrusion 42. The guide portion 43 is disposed on the outer periphery of the upper end portion of the lower support body 2 below the protrusion 42. The inner diameter of the guide portion 43 is larger than the outer diameter of the lower support body 2. The gap between the inner peripheral surface 43c of the guide portion 43 and the outer peripheral surface 2d of the lower support body 2 increases from the top to the bottom.

[0021] As shown in FIG. 6 , a scaffold 5 is provided on the upper end portion of the inner peripheral surface 2c of the lower support 2 when the lower support 2 and the upper support 3 are joined. The scaffold 5 includes a scaffold plate 51 and a bracket 52. The scaffold plate 51 is a steel disk whose planar shape is approximately the same diameter as the interior of the lower support 2. The bracket 52 is an annular steel member. The bracket 52 is joined to the inner peripheral surface of the lower support 2. The bracket 52 protrudes inward from the inner peripheral surface of the lower support 2. The scaffold plate 51 is placed on the bracket 52. Instead of being annular, the bracket 52 may be a plurality of members provided radially spaced apart on the inner peripheral surface of the lower support 2. The bracket 52 is joined to the inner peripheral surface of the lower support 2 in advance before the lower support installation process. The scaffold plate 51 is lifted and placed on the bracket 52 after the lower support installation process on site.

[0022] The construction method for wind power generation supports will be explained. The lower support 2 is cast into the seabed (lower support installation step). The scaffolding plate 51 is lifted and installed onto the bracket 52 of the cast lower support 2.

[0023] The upper support 3 is placed on the lower support 2 (upper support placement step). As described above, the skirt portion 4 is joined to the main body portion 31 before the upper support placement step. The skirt portion 4 may be joined to the main body portion 31 on-site, or may be joined to the main body portion 31 in a factory or the like before being delivered to the site. As shown in FIGS. 7 and 8 , the upper support 3 is lifted above the lower support 2, and the upper support 3 is lowered. The lower support 2 is inserted inside the guide portion 43 of the skirt portion 4. The lower end of the guide portion 43 is provided with a tapered guide portion 43 with an inner diameter larger at the bottom than at the top, which makes it easy to insert the lower support 2 inside the guide portion 43 and align the lower support 2 and the upper support 3. The upper support 3 is lowered, and the bottom end of the main body 31 is butted against the top end of the lower support 2. The sealant 44 attached to the protruding portion 42 of the skirt portion 4 comes into contact with the outer periphery of the lower support 2, preventing any gap from forming between the outer surface of the lower support 2 and the inner surface of the protruding portion 42. The worker performs the work while standing on the scaffolding plate 51.

[0024] When a root gap G is provided between the upper end surface 2a of the lower support 2 and the lower end surface 31a of the main body 31, a height adjustment member 8 is installed between the upper end surface 2a of the lower support 2 and the lower end surface 31a of the main body 31 in the upper support arrangement step, as shown in Fig. 9. The adjustment member 8 is, for example, a wedge-shaped member. The adjustment member 8 is placed in a portion that will not be welded during tack welding.

[0025] As shown in FIG. 10 , fine adjustment of the horizontal position of the upper support 3 relative to the lower support 2 is performed using a jack unit 6. The jack unit 6 has a jack 61, a jack receiving bracket 62, and a guide rail 63. The guide rail 63 is provided in an annular shape around the entire circumferential direction on the inner circumferential surface of the main body 31 of the upper support 3. The jack receiving bracket 62 is movable in the circumferential direction along the guide rail 63. The jack 61 is attached to the lower end of the jack receiving bracket 62. The jack 61 is positioned at the same height as the lower support 2. The horizontal position of the upper support 3 relative to the lower support 2 is adjusted by pushing and pulling the lower support 2 with the jack 61.

[0026] The lower support body 2 and the upper support body 3 are welded together (welding step). First, the lower support 2 and the main body 31 of the upper support 3 are tack-welded together. The lower support 2 and the main body 31 are tack-welded at four or more locations spaced apart in the circumferential direction. The tack welding is performed from the inside of the lower support 2 and the main body 31. The tack welding is performed from the outside to the inside in the radial direction of the lower support 2 and the main body 31, forming multiple layers of filler material. The radially inner layer is welded shorter in the circumferential direction than the radially outer layer. By doing this, as shown in FIG. 11 , the filler material of the tack-welded portion (hereinafter referred to as a tack weld 72) is shorter in the width direction (circumferential direction) on the inside than on the outside in the radial direction. That is, the circumferential length of the tack weld 72 gradually decreases from the outside to the inside in the radial direction. The tack weld 72 may be configured so that the central angle of the arcuate surface of the inner peripheral surface is smaller than the central angle of the arcuate surface of the outer peripheral surface. 12, tack welding is performed automatically or by remote control using a welding robot 7. The welding robot 7 is attached to a guide rail 63 provided on the main body 31, and is movable along the guide rail 63. Once the tack welding is complete, the sling wire of the crane lifting the upper support body 3 is removed. Also, after the tack welding is complete, the adjustment member 8 is removed. Main welding, which will be described later, is performed after the adjustment member 8 has been removed.

[0027] Next, the lower support body 2 and the main body portion 31 of the upper support body 3 are permanently welded together. The permanent welding is performed from the inside of the lower support body 2 and the main body portion 31. The permanent welding is performed between circumferentially adjacent tack welds 72. The filler material in the permanently welded portion is referred to as the permanent weld 73. In FIG. 11 , the area where the permanent welds are located, i.e., the area where the permanent welds are performed, is indicated by the reference numeral 73. The permanent welding is performed using multiple welding robots 7 installed on the guide rail 63. As described above, the tack welds 72 are shorter in the width direction (circumferential direction) on the inside than on the outside in the radial direction. This prevents the tack welds from obscuring the areas to be permanently welded when welding is performed from the inside of the upper support body 3, and enables welding to be performed without creating a gap between the tack welds 72 and the permanent welds 73. In this embodiment, a root gap G is provided between the upper end surface 2a of the lower support 2 and the lower end surface 31a of the main body 31, and the lower support 2 and the upper support 3 are fully penetrated and welded together. Because the skirt portion 4 is disposed outside the root gap G, it can be used as a backing plate for welding, allowing welding work to be performed without being affected by waves and wind.

[0028] After the actual welding is completed, a non-destructive inspection is performed on the welded portion to check the quality, and the scaffolding plate 51 is removed. If necessary, grout is filled in the gap between the outer peripheral surface 2d of the lower support 2 and the inner peripheral surface 42c of the protruding portion 42 of the skirt portion 4. At this time, the grout is used to fill the gap, and a smaller amount is used than when used for connection.

[0029] Next, the functions and effects of the wind turbine support body and the wind turbine support body construction method according to this embodiment will be described. When connecting the lower support and the upper support with flanges and bolts, it is necessary to use ministerially approved flanges and bolts. The outer diameters of the lower support and the upper support must be suitable for the ministerially approved flanges and bolts, which imposes an upper limit on the outer diameters of the lower support and the upper support. In contrast, in the wind power generation support 1 and the construction method for the wind power generation support 1 according to this embodiment, the lower support 2 and the upper support 3 are welded together, so the lower support and the upper support can be connected regardless of the outer diameters of the lower support 2 and the upper support 3. In addition, costs can be reduced because there is no need to use special components or grout for connections.

[0030] In this embodiment, when connecting the upper support 3 and the lower support 2, temporary welding is performed while the upper support 3 is lifted by a crane, and then the upper support 3 is removed from the crane's sling wire and main welding is performed, thereby shortening the usage time of the SEP vessel for lifting the upper support 3 and reducing construction costs.

[0031] In this embodiment, the upper end surface 2a of the lower support 2 is a surface perpendicular to the axial direction, and the lower end surface 31a of the main body portion 31 of the upper support 3 is an inclined surface that gradually slopes upward from the radial outside toward the radial inside. With this configuration, a groove is formed between the upper end surface 2a of the lower support body 2 and the lower end surface 31a of the main body portion 31 of the upper support body 3, allowing the lower support body 2 and the upper support body 3 to be welded together well.

[0032] In this embodiment, a root gap G is provided between 2 a of the lower support 2 and the lower end surface 31 a of the main body portion 31 . With this configuration, the lower support body 2 and the upper support body 3 can be welded together by full penetration welding.

[0033] In this embodiment, the skirt portion 4 is provided at its lower end with a tapered guide portion 43 whose diameter gradually increases downward. With this configuration, when installing the upper support 3 on the lower support 2, the lower support 2 can be easily inserted into the inside of the skirt portion 4, resulting in good workability.

[0034] In this embodiment, a seal material 44 that comes into contact with the outer peripheral surface 2d of the lower support body 2 is provided on the inner peripheral surface of the protruding portion 42 of the skirt portion 4. With this configuration, the sealing material 44 can seal the gap between the skirt portion 4 and the lower support 2, preventing outside air, water such as rain or seawater, sand, etc. from entering the inside of the wind turbine support 1 through the gap between the skirt portion 4 and the lower support 2. As a result, deterioration and salt damage to the wind turbine support 1 can be suppressed.

[0035] In the welding process of this embodiment, the lower support body 2 and the main body portion 31 of the upper support body 3 are welded together by a welding robot 7. This configuration reduces labor costs and ensures uniform welding quality.

[0036] The above describes embodiments of the wind turbine support and the wind turbine support construction method according to the present invention, but the present invention is not limited to the above embodiments and can be modified as appropriate within the scope of the spirit of the present invention. For example, the wind power generation support 1 in the above embodiment is a wind power generation support for an offshore wind power generation facility 11, but may also be a wind power generation support for an onshore wind power generation facility. The shape of the groove between the upper end surface 2a of the lower support body 2 and the lower end surface 31a of the main body portion 31 of the upper support body 3 may be set appropriately, and the shapes of the upper end surface 2a of the lower support body 2 and the lower end surface 31a of the main body portion 31 may also be set appropriately. The root gap G does not need to be provided between the lower support body 2 and the upper support body 3.

[0037] The lower end of the skirt portion 4 does not necessarily have to be provided with the tapered guide portion 43 . The inner peripheral surface of the protruding portion 42 of the skirt portion 4 does not necessarily need to be provided with the seal material 44 that comes into contact with the outer peripheral surface 2 d of the lower support body 2 . The welding between the lower support body 2 and the main body portion 31 of the upper support body 3 does not need to use the welding robot 7 . The shapes of the tack weld 72 and the main weld 73 of the weld 71 between the lower support body 2 and the main body 31 of the upper support body 3 may be other than those described above. The welding between the lower support body 2 and the main body 31 of the upper support body 3 may be performed by a method other than those described above.

[0038] The position of the upper support 3 relative to the lower support 2 may be adjusted by a method other than the above. The scaffolding 5 installed inside the lower support 2 may have a form other than that described above.

[0039] The Sustainable Development Goals (SDGs) are 17 international goals adopted at the United Nations Summit in September 2015. The wind power generation support and the construction method for the wind power generation support according to this embodiment can contribute to achieving one of the 17 SDGs, for example goal 7, "Affordable and clean energy." [Explanation of symbols]

[0040] 1. Wind power generation support 2 Lower support 2a Upper end surface 3 Upper support 4 Skirt section 5. Scaffolding 7. Welding robot 31 Main body 31a Lower end surface 43 Guide section 44 Sealing material 71 Welded section 72 Tack weld 73 welds G Route Spacing

Claims

1. A cylindrical lower support; a cylindrical upper support member that is coaxially disposed on the lower support member and welded to the lower support member; The upper support includes: a cylindrical main body portion disposed on the lower support; a cylindrical skirt portion coaxially joined to the outer periphery of the main body portion and protruding downward from the main body portion, an upper end portion of the lower support is inserted into the inside of the skirt portion; A wind power generation support in which the upper end of the lower support and the lower end of the main body are welded together.

2. an upper end surface of the lower support body is a surface perpendicular to the axial direction; The wind turbine support according to claim 1 , wherein the lower end surface of the main body is an inclined surface that gradually slopes upward from the outside to the inside in the radial direction of the main body.

3. The wind turbine support according to claim 1 or 2, wherein a root gap is provided between an upper end of the lower support and a lower end of the main body.

4. 3. The wind turbine support according to claim 1, wherein a tapered guide portion having a diameter gradually increasing downward is provided at a lower end of the skirt portion.

5. The welded portion between the upper end surface of the lower support body and the lower end surface of the main body portion is a tack weld that welds an upper end surface of the lower support body and a lower end surface of the main body portion at a predetermined position in the circumferential direction; a main weld portion that welds the upper end surface of the lower support body and the lower end surface of the main body portion at a position circumferentially adjacent to the temporary weld portion, The wind turbine support according to claim 1 or 2, wherein the tack welded portions have a circumferential length that gradually decreases from the outer side to the inner side in the radial direction.

6. a lower support installation step of installing a cylindrical lower support; an upper support arrangement step of suspending a cylindrical upper support on the lower support and arranging it coaxially; a welding step of welding the lower support body and the upper support body together, The upper support includes: a cylindrical main body portion disposed on the lower support; a cylindrical skirt portion coaxially joined to the outer periphery of the main body portion and protruding downward from the main body portion, In the upper support positioning step, an upper end portion of the lower support is inserted inside the skirt portion, In the welding step, an upper end of the lower support and a lower end of the main body are welded together.

7. In the welding step, a tack welding process of welding an upper end surface of the lower support body and a lower end surface of the main body portion at predetermined positions in a circumferential direction; a main welding process of welding an upper end surface of the lower support body and a lower end surface of the main body portion at a position circumferentially adjacent to a portion welded in the tack welding process, The construction method for a wind turbine support according to claim 6, wherein the tack welding step includes welding the welded portion so that the circumferential length of the welded portion gradually decreases from the outer side toward the inner side in the radial direction.

8. The upper end surface of the lower support is formed in a plane perpendicular to the axial direction, 8. The method for constructing a wind turbine support according to claim 6 or 7, wherein the lower end surface of the main body is formed into an inclined surface that gradually slopes upward from the outside to the inside in the radial direction of the main body.

9. The construction method for a wind turbine support according to claim 6 or 7, wherein in the upper support arranging step, a root gap is provided between an upper end of the lower support and a lower end of the main body.

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