Method for constructing offshore wind turbine

Abstract

To provide a construction method of an offshore wind turbine capable of installing the offshore wind turbine more efficiently than before.SOLUTION: In the construction method of the offshore wind turbine 1 by the suction bucket jacket, a suction bucket 10 arranged on a land part near a quay is arranged on a sea bottom part near the quay by a crane 50. An assembling step of assembling the jacket 20 by the crane 50; and a step of installing the wind turbine member 30 disposed on the shore-side land portion on an upper portion of the assembled jacket 20 by the crane 50. The method includes a wind turbine member installation step, an auxiliary floating body arrangement step of arranging the auxiliary floating body 40 on the assembled offshore wind turbine 1, a floating step of floating the assembled offshore wind turbine 1, a towing step of towing the offshore wind turbine 1 on which the auxiliary floating body 40 is arranged to an installation location of the offshore wind turbine 1, and a penetration step of penetrating the suction bucket 10 into the seabed at the installation location of the offshore wind turbine 1.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a method for installing an offshore wind turbine using a suction bucket jacket. [Background technology]

[0002] The suction foundation method has been used for a long time as a foundation construction method for offshore structures such as offshore wind power plants. This suction foundation method uses a suction bucket that has a top plate that is connected to the superstructure of the offshore wind turbine or the like and a cylindrical side wall that extends downward integrally from the top plate.

[0003] Then, with the tip of the side wall portion penetrated into the bottom ground, seawater is discharged from the area defined by the top plate portion, the side wall portion, and the bottom ground, a suction load is applied, and the suction bucket is penetrated to a predetermined depth and sunk (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2020-023838 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as wind turbines and towers become larger, foundations also become larger, requiring the use of the few available super-large floating cranes.For example, as shown in Figure 1, when installing a foundation (suction bucket and jacket), the foundation must be lifted from land using a large crane barge (Figure (a)), then transported to the sea area where the foundation is to be installed (Figure (b)), and after the foundation is lowered and installed (Figure (c)), the wind turbine is then installed using the crane barge (Figure (d)), which requires a lot of time and effort.

[0006] In view of the above-mentioned problems, the present invention aims to provide an offshore wind turbine construction method that enables offshore wind turbines to be installed more efficiently than conventional methods. [Means for solving the problem]

[0007] The invention pertaining to (1) is a method for constructing an offshore wind turbine using a suction bucket jacket, comprising: an assembly step of using a lifting machine to place a suction bucket placed on land near a quay on the seabed near the quay and assembling the jacket; a wind turbine component installation step of using the lifting machine to install wind turbine components placed on land near the quay on top of the assembled jacket; an auxiliary floater installation step of placing an auxiliary floater on the assembled offshore wind turbine; a floating step of floating the assembled offshore wind turbine; a towing step of towing the offshore wind turbine with the auxiliary floater placed on it to the installation site of the offshore wind turbine; and a penetration step of penetrating the suction bucket into the seabed at the installation site of the offshore wind turbine.

[0008] The invention related to (2) is the construction method for an offshore wind turbine described in (1) above, characterized in that in the assembly step, an exhaust valve provided on the top plate of the suction bucket is opened to discharge the air inside the suction bucket, and the suction bucket is landed on the seabed near the quay.

[0009] The invention related to (3) is the construction method for an offshore wind turbine described in (2) above, characterized in that in the floating step, the exhaust valve is closed and air is supplied into the suction bucket from an air supply pipe connected to the top plate of the suction bucket, thereby floating the offshore wind turbine.

[0010] The invention according to (4) is the construction method for an offshore wind turbine described in (3) above, characterized in that in the penetration step, the exhaust valve is opened to discharge the air in the suction bucket, and the suction bucket is penetrated into the seabed by the weight of the offshore wind turbine.

[0011] The invention according to (5) is the construction method for an offshore wind turbine described in (3) above, characterized in that in the penetration step, the exhaust valve is opened to discharge the air in the suction bucket, and the seawater in the suction bucket is drained using the air supply pipe, causing the suction bucket to penetrate the seabed. [Effects of the Invention]

[0012] According to the present invention, there is no need to transport the offshore wind turbine to the installation area using a large crane ship or barge, as was previously required, and to assemble the offshore wind turbine at the installation site. This not only allows for significant cost reductions, but also enables the offshore wind turbine to be assembled near a quay where it is less susceptible to the effects of waves, making it possible to assemble the offshore wind turbine safely and efficiently. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram illustrating the installation process of a conventional offshore wind turbine. [Figure 2] FIG. 2 is a side view of a suction bucket jacket according to an embodiment of the present invention. [Figure 3] FIG. 2 is a plan view of a suction bucket jacket in an embodiment of the present invention. [Figure 4] FIG. 1 is a diagram illustrating the installation process of an offshore wind turbine in one embodiment of the present invention. [Figure 5] FIG. 1 is a diagram illustrating the installation process of an offshore wind turbine in one embodiment of the present invention. [Figure 6] FIG. 2 is a cross-sectional view illustrating the procedure for landing a suction bucket on the bottom in one embodiment of the present invention. [Figure 7] FIG. 2 is a cross-sectional view showing a state in which a suction bucket has landed on the bottom in one embodiment of the present invention. [Figure 8] 5A to 5C are cross-sectional views illustrating a procedure for floating a suction bucket in one embodiment of the present invention. [Figure 9] 10A to 10C are cross-sectional views illustrating the procedure for penetration of a suction bucket by the weight of an offshore wind turbine in one embodiment of the present invention. [Figure 10] 1 is a cross-sectional view illustrating a procedure for sinking a suction bucket by suction penetration in one embodiment of the present invention. FIG. [Figure 11] FIG. 2 is a perspective view showing an example of an auxiliary floating body. [Figure 12] FIG. 2 is a perspective view showing an example of an auxiliary floating body. [Figure 13] FIG. 2 is a perspective view showing an example of an auxiliary floating body. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the offshore wind turbine construction method of the present invention will be described with reference to the drawings.

[0015] Fig. 2 shows a side view of the suction bucket jacket in the offshore wind turbine 1 of this embodiment, and Fig. 3 shows a plan view of the suction bucket jacket. As shown in the figures, the suction bucket jacket of this embodiment is equipped with three suction buckets 10, and a jacket 20 made of a steel pipe column or the like is assembled on top of them.

[0016] A wind turbine component 30 (not shown) is attached to the top of the jacket 20. The suction bucket jacket shown in the figure has a height of approximately 90 m from the bottom of the suction bucket 10 to the top of the jacket 20, and to lift it using conventional construction methods, a 4,100-ton class crane ship would be required.

[0017] Next, the construction procedure for the offshore wind turbine in this embodiment will be described in detail.

[0018] As shown in the drawings illustrating the installation process of the offshore wind turbine 1 in FIGS. 4 and 5, the construction method of this embodiment includes an "assembly step" (FIG. 4(a)) in which the suction bucket 10 placed on the land side of the quay is placed on the seabed side of the quay by a crane 50, and the jacket 20 is assembled by the crane 50, and a "wind turbine component installation step" (FIG. 4(b)) in which the wind turbine components 30 placed on the land side of the quay are installed on top of the assembled jacket 20 by the crane 50. The offshore wind turbine 1 has at least an "auxiliary float placement step" (Fig. 4(c)) for placing an auxiliary float 40 on the assembled offshore wind turbine 1, a "floating step" for floating the assembled offshore wind turbine 1, a "towing step" (Fig. 5(d)) for towing the offshore wind turbine 1 with the auxiliary float 40 placed thereon to the installation site of the offshore wind turbine 1, and a "penetration step" (Fig. 5(e)) for penetrating the suction bucket 10 into the seabed at the installation site of the offshore wind turbine 1.

[0019] That is, in the above-mentioned "assembly step," as shown in FIG. 4(a), the suction bucket 10, jacket 20, etc. are brought in and temporarily placed on land near the quay, and assembly is carried out by a lifting machine 50 arranged on land near the quay.

[0020] During assembly work, the suction bucket 10, or a partial assembly of the suction bucket 10 and jacket 20, is lifted by the crane 50, lowered into the sea, and placed on the seabed near the quay. At this time, it is also possible to install a template in advance to accurately position it on the seabed, which enables efficient assembly work.

[0021] The jacket 20, which has been transported and temporarily placed on land near the quay, is then assembled one by one by a crane 50. This procedure makes it possible to lift the various components in sections, eliminating the need for a conventional large crane ship and making it possible to use a mobile crane or a crane installed on the quay.

[0022] In addition, the top plate 12 of the suction bucket 10 of this embodiment is provided with an exhaust valve 11, as shown in Figure 6. That is, when the suction bucket 10 is placed on the seabed near the quay, the exhaust valve 11 is opened to discharge the air inside the suction bucket 10, making it possible to adjust the buoyancy of the suction bucket 10 and allow it to land on the seabed.

[0023] This prevents the suction bucket 10 from sinking significantly into the seabed, allowing the suction bucket 10 to land stably on the seabed, as shown in Figure 7. Note that the exhaust valve 11 may be a butterfly valve or any other known valve.

[0024] Furthermore, as assembly progresses, the weight of the suction bucket jacket increases, and if this could cause the suction bucket 10 to sink significantly into the seabed, the buoyancy of the suction bucket 10 can be adjusted by sending air into the suction bucket 10 using the air supply pipe 13, which will be described later.

[0025] Of course, this can also be addressed by using a strong template (made of concrete, steel, or the like) to prevent the suction bucket 10 from sinking significantly into the seabed.

[0026] Next, in the "wind turbine component installation step," as shown in Figures 4(a) and (b), the wind turbine components 30 and the like are transported and temporarily placed on land near the quay, and the wind turbine components 30 are installed using a lifting machine 50 positioned on the land near the quay.

[0027] In the installation work of the wind turbine components 30, the wind turbine components 30 may be assembled on land near the quay, and the assembled wind turbine components 30 may be placed on top of the jacket 20 using a lifting machine 50, or each part of the wind turbine components 30 may be assembled and placed using the lifting machine 50.

[0028] Once the assembly of the offshore wind turbine 1 is completed through the steps described above, the auxiliary floating body 40 is placed on the assembled offshore wind turbine 1 in the "auxiliary floating body placing step."

[0029] The assembled offshore wind turbine 1 is then floated in the "floating step" as shown in Figure 8. Specifically, the exhaust valve 11 is closed and air is supplied into the suction bucket 10 from the air supply pipe 13 connected to the top plate 12 of the suction bucket 10, causing the offshore wind turbine 1 to float by the resulting buoyancy.

[0030] The air supply pipe 13 in this embodiment is laid inside the jacket 20 and connected to the top plate 12 of the suction bucket 10 without providing a pump chamber.

[0031] Next, in the "towing step", the offshore wind turbine 1 on which the auxiliary floating body 40 is arranged is towed to the installation site of the offshore wind turbine 1 as shown in FIG. 5(d).

[0032] Once the towing to the installation site of the offshore wind turbine 1 is completed, the suction bucket 10 penetrates the seabed in the "penetration step." At this time, the auxiliary floating body 40 may remain in place as shown in Figure 5(e), or may be removed beforehand.

[0033] In the "penetration step," as shown in Figure 9, one method is to open exhaust valve 11 to discharge the air inside suction bucket 10 and have suction bucket 10 penetrate into the seabed using the weight of offshore wind turbine 1, but as shown in Figure 10, it is also possible to open exhaust valve 11 to discharge the air inside suction bucket 10 and then use air supply pipe 13 to drain seawater from suction bucket 10, allowing suction bucket 10 to penetrate into the seabed.

[0034] More specifically, the seawater in the suction bucket 10 is sucked and drained using a pump using the air supply pipe 13, and the suction obtained by reducing the water pressure in the suction bucket 10 (the pressure inside the suction bucket 10 becomes equal to or less than the hydrostatic pressure due to drainage) and the weight of the offshore wind turbine 1 allow the suction bucket 10 to penetrate. Once the penetration of the suction bucket 10 is complete, the auxiliary floating body 40 is removed, as shown in Figure 5(f).

[0035] (Another embodiment) The offshore wind turbine construction method of the present invention has been described above in relation to one embodiment thereof. However, the present invention is not necessarily limited to the above embodiment, and the following modifications are possible.

[0036] The suction bucket jacket in the embodiment described above is provided with three suction buckets 10, but the construction method for an offshore wind turbine of the present invention is not necessarily limited to the number of suction buckets 10.

[0037] Furthermore, the above-mentioned "floating step" and "auxiliary float placing step" may be performed in any order. That is, the offshore wind turbine 1 may be floated by the "floating step", and then the auxiliary float 40 may be placed by the "auxiliary float placing step", or, without being limited to this, the offshore wind turbine 1 may be floated by the "floating step" after the auxiliary float 40 is placed by the "auxiliary float placing step".

[0038] 11 to 13 can be used as an example of the aforementioned auxiliary floating body 40. That is, as shown in FIG. 11, it is possible to place a substantially box-shaped auxiliary floating body 40 below the jacket 20.

[0039] Furthermore, as shown in FIG. 12, it is also possible to use an auxiliary floating body 40 (hollow main body portions 40A, 40B, 40C) arranged so as to surround the jacket 20.

[0040] 13, each of main bodies 40A, 40B, 40C of auxiliary floating body 40 is provided with suspending means 431 (e.g., a winch) for suspending suction bucket 10, and suction bucket 10 can be lowered or raised in the water by wire 432. Therefore, offshore wind turbine 1 can be stably held not only when towing but also during the "floating step" and "penetration step" described above.

[0041] Although the embodiment and other embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments.

[0042] The scope of the present invention is defined by the claims rather than the description of the above embodiments, and includes all modifications within the meaning and scope of the claims. Furthermore, the specific materials, dimensions, shapes, etc. described in the above embodiments can be modified within the scope of solving the problems of the present invention. [Explanation of symbols]

[0043] 1. Offshore wind turbines 10 Suction Bucket 11 Exhaust valve 12 Top plate section 13 Air pipe 20 Jacket 30 Wind turbine components 40 Auxiliary Floating Body 50 Lifting Machine

Claims

1. A construction method for an offshore wind turbine using a suction bucket jacket, an assembly step of placing the suction bucket arranged on land near the quay on the seabed near the quay by a lifting machine and assembling the jacket by the lifting machine; a wind turbine component installation step of installing the wind turbine components arranged on the land portion near the quay on top of the assembled jacket by the lifting machine; an auxiliary floating body arranging step of arranging an auxiliary floating body on the assembled offshore wind turbine; a floating step for floating the assembled offshore wind turbine; a towing step of towing the offshore wind turbine on which the auxiliary floating body is disposed to an installation site of the offshore wind turbine; and a penetration step of penetrating the suction bucket into the seabed at an installation site of the offshore wind turbine. A construction method for an offshore wind turbine.

2. In the assembly step, An exhaust valve provided on the top plate of the suction bucket is opened to discharge the air from the suction bucket, and the suction bucket is landed on the seabed near the quay. The offshore wind turbine construction method according to claim 1 .

3. In the floating step, The exhaust valve is closed, and air is supplied into the suction bucket from an air supply pipe connected to the top plate of the suction bucket, thereby floating the offshore wind turbine. The offshore wind turbine construction method according to claim 2 .

4. In the penetration step, The exhaust valve is opened to discharge the air from the suction bucket, and the suction bucket penetrates into the seabed by the weight of the offshore wind turbine. The offshore wind turbine construction method according to claim 3 .

5. In the penetration step, The exhaust valve is opened to discharge the air from the suction bucket, and the seawater in the suction bucket is drained through the air pipe, causing the suction bucket to penetrate the seabed. The offshore wind turbine construction method according to claim 3 .

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