Temporary floater

Abstract

To provide a temporary floater which can temporarily reduce the draft of a floating body structure.SOLUTION: A temporary floater 4 for increasing the buoyance of a floating body type foundation 3 comprises: a plurality of hollow floater bodies 41 attached to the floating body type foundation 3; and wire rods 42 for fastening down the floater bodies 41 to the floating body type foundation 3. Each floater body 41 is a bag body having flexibility. The wire rods 42 are installed around the upper faces, lower faces and outside faces of a pair of floater bodies 41, 41 facing each other with the floating body type foundation 3 sandwiched.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a temporary floater for increasing the buoyancy of a floating structure. [Background technology]

[0002] For example, the floating foundation of a wind power generation facility tends to have an increased draft due to the weight of the wind turbines, etc., when the wind turbines, etc. are installed from a quay in a port using a crane, etc. Therefore, when the water depth in the port is shallower than the draft, it is necessary to increase the buoyancy of the floating foundation to suppress the increase in the draft. Patent Document 1 discloses a semi-submersible floating structure having a center column and side columns, in which openings are provided in the side columns for transporting ballast in and out, and the draft of the floating structure is adjusted by transporting ballast in and out of the side columns through these openings. The floating structure in Patent Document 1 had to be large enough to ensure the necessary buoyancy by itself. Therefore, as wind turbines become larger, the floating structure also becomes larger, which may become uneconomical. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-280301 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to propose a temporary floater that makes it possible to temporarily reduce the draft of a floating structure. [Means for solving the problem]

[0005] The present invention for solving the above problems is a temporary floater for increasing the buoyancy of a floating structure, comprising a plurality of hollow floater bodies attached to the floating structure, and wires for fastening the floater bodies to the floating structure. It is preferable that the wires are provided around the upper, lower and outer surfaces of a pair of the floater bodies facing each other across the floating structure. Such a temporary floater can temporarily increase the buoyancy of the floating structure. In addition, since the floater bodies are fixed to the floating structure by winding wire around a pair of floater bodies facing each other across the floating structure, the temporary floater can be installed without extensive processing of the floating structure. In addition, since the floater bodies are appropriately disposed relative to the floating structure, the buoyancy can be increased in a well-balanced manner.

[0006] If the floater body is a flexible bag, it can be folded when not in use and does not take up space during transportation or storage. Also, when removing it from a floating structure, it can be easily removed by deflating it by letting the air inside it out. If a deformation prevention material is provided inside the floater body made of a bag, extending from the corners between the upper surface and the outer surface to the corners between the lower surface and the inner surface, deformation when buoyancy acts on it can be suppressed and buoyancy can be applied to the floating structure in a balanced manner.

[0007] If the height dimension (thickness) of the floater body is equivalent to the height dimension (thickness) of the floating structure at the position where the floater body is attached, it becomes easier to secure the floater body to the floating structure and it can be secured more firmly. Furthermore, if a bottom plate is provided extending from the underside of the floater body to the underside of the floating structure, misalignment between the floater body and the floating structure can be suppressed when buoyancy acts, and balancing buoyancy can be added to the floating structure. Furthermore, it is preferable that the wire is a first linear member provided around the upper, lower and outer surfaces of one of the floater bodies and a second linear member provided around the upper, lower and outer surfaces of the other of the floater bodies, which are connected at the upper and lower surfaces of the floating structure. In this way, the wire can be easily fastened and the floater bodies can be fixed more firmly. Effect of the Invention

[0008] According to the temporary floater of the present invention, it is possible to temporarily reduce the draft of a floating structure. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a wind power generation facility according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a plan view showing the foundation launching process. [Figure 4] FIG. 2 is a perspective view showing a floating foundation on which a temporary floater is installed. [Diagram 5] FIG. 2 is a cross-sectional view of the temporary floater of the first embodiment. [Figure 6] FIG. [Figure 7] 10 is a cross-sectional view showing an example of deformation of a floater body when buoyancy acts thereon. FIG. [Figure 8] A cross-sectional view of a temporary floater of a second embodiment. [Figure 9] A cross-sectional view of a temporary floater of a third embodiment. [Figure 10] FIG. 11 is a cross-sectional view of a temporary floater according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First Embodiment In the first embodiment, a case will be described where a wind power generation facility 1 is constructed. Fig. 1 shows the wind power generation facility 1 of this embodiment. The wind power generation facility 1 is an offshore wind power generation facility, and includes a wind turbine 21, an upper structure 2 having columns 22 supporting the wind turbine 21, and a floating foundation (floating structure) 3 supporting the upper structure 2. The upper structure 2 is provided at a position higher than the water surface via the floating foundation (float) 3 moored on the water. The wind turbine 21 includes a nacelle 23 provided on the upper end of a support 22, a rotor 24 provided at the tip of the nacelle 23, and a plurality of blades 25, 25, 25 (three in this embodiment) provided radially around the rotor 24. The rotor 24 (blades 25) is rotatable about a horizontal axis and is supported by the nacelle 23. The nacelle 23 is rotatable about a vertical axis and is supported by the support 22. The support (tower) 22 is erected on a floating foundation 3.

[0011] The floating foundation 3 of this embodiment comprises a center column 31 that supports the support pillars 22 of the wind turbine 21, four side columns 32, 32, ... arranged at intervals around the center column 31, and beams 33, 33, ... that connect the center column 31 to each side column 32. As shown in FIG. 1, the center column 31 has a cylindrical shape and is disposed in the center of the floating foundation 3 . The four side columns 32 are cylindrical and arranged around the center column 31. The intervals between adjacent side columns 32 are the same. The side columns 32 are connected to the center column 31 via beams 33. The beam 33 connects the center column 31 and the side column 32. One end of the beam 33 is connected to the center column 31, and the other end of the beam 33 is connected to the side column 32. The beam 33 in this embodiment has a shape of a rectangular column turned sideways, but the cross-sectional shape of the beam 33 is not limited thereto.

[0012] Next, a construction method for the wind power generation facility 1 will be described. First, the floating foundation 3 is fabricated on the ground. Figure 2 is a plan view showing the fabrication of the floating foundation. In this embodiment, as shown in Figure 2, the floating foundation 3 is fabricated at a floating foundation fabrication site A1 provided in a port. The floating foundation 3 (center column 31, side columns 32, and beams 33) is fabricated by connecting segments fabricated in various ways. Note that the method of fabricating the floating foundation 3 is not limited to the method of fabricating it by combining precast members. The quay next to the manufacturing (assembly) site of the floating foundation 3 faces the sea where the manufactured floating foundation 3 will be towed and installed, and the manufactured floating foundation 3 is loaded onto a barge B moored to the quay using a crane or other device and transported to the designated installation location.

[0013] Next, the floating foundation 3 is launched. FIG. 3 is a plan view showing the launching of the floating foundation 3. The floating foundation 3 is loaded onto a barge B, and then the barge B is towed to a predetermined location as shown in FIG. 3. At this time, a temporary floater 4 (see FIG. 4) is attached to the floating foundation 3 on land before it is loaded onto the barge B. In this embodiment, the floating foundation 3 is temporarily placed between the floating foundation manufacturing site A1 and the wind turbine installation site A2 in the port. The floating foundation 3 may be temporarily placed as needed. When the floating foundation 3 is temporarily placed, the location for temporary placement may be determined as appropriate.

[0014] The temporary floater 4 is attached to the floating foundation 3 to increase the buoyancy of the floating foundation 3. Figures 4 and 5 show the floating foundation 3 with the temporary floater 4 installed. As shown in Figures 4 and 5, the temporary floater 4 comprises a plurality of hollow floater bodies 41, 41, ... attached to the floating foundation 3, and wires 42 for fastening the floater bodies 41 to the floating foundation 3. The floater body 41 is a flexible bag. Air is pressurized into the inside of the floater body 41. The floater body 41 has a triangular prism shape and is interposed between adjacent beams 33, 33. The height dimension of the floater body 41 is equal to the height dimension of the beam 33 (the height dimension of the floating foundation 3 at the position where the floater body 41 is attached). The shape and dimensions of the floater body 41 are not limited. The material constituting the floater body 41 is not limited, and may be, for example, made of resin or may be a coated cloth to ensure airtightness. The bag constituting the floater body 41 may be a double structure to ensure the necessary strength.

[0015] The wire 42 is provided around the upper, lower and outer surfaces of a pair of floater bodies 41, 41 facing each other across the floating foundation 3. That is, the wire 42 is provided so as to surround the beam 33 and the pair of floater bodies 41, 41. The material constituting the wire 42 is not limited as long as it has flexibility and a predetermined strength, and in this embodiment, a wire is used. The wire 42 includes a first linear member 43 provided around the upper, lower and outer surfaces of one floater body 41, a second linear member 44 provided around the upper, lower and outer surfaces of the other floater body 41, and a connecting jig 45 interposed between the first linear member 43 and the second linear member 44. The pair of floater bodies 41, 41 are fixed to the floating foundation 3 by connecting the first linear member 43 and the second linear member 44 via the connecting jig 45 on the upper and lower surfaces of the beam 33. The wire 42 may be fixed to the floater body 41, or may be independent from the floater body 41. Furthermore, the method of fixing the floater body 41 with the wire 42 is not limited, and for example, the wire 42 may also be disposed on the inner surface of the floater body 41.

[0016] In this embodiment, as shown in Fig. 5, a deformation prevention member 5 is provided inside the floater body 41. The deformation prevention member 5 prevents the outer part of the floater body 41 (opposite the floating foundation 3) from deforming so as to become higher than the inner part (on the floating foundation 3 side) when buoyancy acts on the temporary floater 4 installed on the floating foundation 3. The deformation prevention member 5 is made of the same material as the wire 42, and is provided so as to extend from the corner between the upper surface and the outer side of the floater body 41 to the corner between the lower surface and the inner side.

[0017] After the floating foundation 3 is moved to a predetermined position, the floating foundation 3 is unloaded from the barge B and temporarily placed. When the floating foundation 3 is unloaded from the barge B and launched, the barge B, which is a semi-submersible barge, is sunk to separate the floating foundation 3 from the barge B, and the floating foundation 3 is launched. After the floating foundation 3 is launched and the barge B is moved, the temporary floater 4 is removed from the floating foundation 3. When the temporary floater 4 is removed, air is discharged from inside the floater body 41, and the floater body 41 and the wires 42 are removed. The draft of the floating foundation 3 increases when the temporary floater 4 is removed. The removed temporary floater 4 is transported to land and attached to another floating foundation 3. If the stability of the floating foundation 3 can be ensured, the temporary floater 4 may remain attached. Also, a crane ship or the like may be used to load and unload the floating foundation 3 from the barge B. When the floating foundation 3 is loaded and unloaded from the barge B using a crane, it is not necessarily necessary to install the temporary floater 4 on land.

[0018] Next, the superstructure 2 is installed on the floating foundation 3. Fig. 6 is a plan view showing the installation of the superstructure 2. As shown in Fig. 6, first, the floating foundation 3 is towed to the wind turbine installation site A2. In this embodiment, the wind turbine installation site A2 is provided on the opposite bank from the floating foundation fabrication site A1. Note that the location of the wind turbine installation site A2 is not limited. Next, the temporary floater 4 is installed for the floating foundation 3. The temporary floater 4 may be installed before towing. The superstructure 2 (wind turbine 21) is installed on the floating foundation 3 using a crane installed on the ground or on an SEP vessel, etc., while the floating foundation 3 is moored. At this time, the buoyancy of the floating foundation 3 is increased by the temporary floater 4, so the increase in draft due to the weight of the superstructure 2 is controlled. The wind power generation facility 1 is formed by installing the superstructure 2 on the floating foundation 3. The wind power generation facility 1 is towed to a designated position as required. Once the wind power generation facility 1 has been towed to the designated position, the temporary floater 4 is removed. After the temporary floater 4 is removed, it can be moved as required.

[0019] According to the temporary floater 4 of this embodiment, the buoyancy of the floating structure can be temporarily increased. The temporary floaters 4 are installed so as to face each other across the floating foundation 3, so that the floating foundation 3 can be supported in a well-balanced manner. By adjusting the amount of air (gas) inside the floater body 41, the buoyancy of the floating foundation 3 can be adjusted, and thus the water draft can be adjusted. The floater body 41 is fixed to the floating foundation 3 by wrapping wire 42 around a pair of floater bodies 41, 41 facing each other across the floating foundation 3, so that the temporary floater 4 can be installed without performing large-scale processing on the floating foundation 3. Since the floater body 41 is a flexible bag, it can be folded when not in use and does not take up much space during transportation or storage.

[0020] When removing the temporary floater 4, the air inside the floater body 41 is released to cause it to deflate, allowing it to be easily removed. Here, the temporary floater 4 uses a flexible bag as the floater body 41, and the wires 42 are also made of a flexible material, so when buoyancy acts on it, there is a risk of deformation occurring in which the side opposite the floating foundation 3 (beam 33) rises up, as shown in Figure 7. On the other hand, the temporary floater 4 of this embodiment is provided with a deformation prevention member 5 inside the floater body 41, so that when buoyancy acts on it, deformation of the floater body 41 is suppressed, and buoyancy can be applied to the floating foundation 3 in a balanced manner.

[0021] Second Embodiment In the second embodiment, as in the first embodiment, a case will be described where a wind power generation facility 1 is constructed. The wind power generation facility 1 is an offshore wind power generation facility, and includes an upper structure 2 and a floating foundation (floating structure) 3 that supports the upper structure 2. The details of the upper structure 2 and the floating foundation 3 are similar to those of the wind power generation facility 1 in the first embodiment, and therefore detailed explanations will be omitted. The temporary floater 4 of the second embodiment is shown in Figure 8. The temporary floater 4 used in the second embodiment comprises a plurality of hollow floater bodies 41, 41, ... attached to the floating foundation 3, wires 42 for fastening the floater bodies 41 to the floating foundation 3, and a bottom plate 46 provided from the underside of the floater bodies 41 to the underside of the floating foundation 3, as shown in Figure 8.

[0022] The details of the floater body 41 and the wire 42 are similar to those described in the first embodiment, and therefore a detailed description thereof will be omitted. The bottom plate 46 is fixed to the lower surface of the floater body 41. The bottom plate 46 in this embodiment is fixed to the floater body 41 with a portion of it protruding from the floater body 41 towards the floating foundation 3. The floater body 41 is fixed to the floating foundation 3 via wires 42 with the bottom plate 46 attached to the underside of the floating foundation 3 . Other construction methods for the temporary floater 4 and the wind power generation facility 1 of the second embodiment are similar to those described in the first embodiment, so detailed explanations will be omitted.

[0023] According to the temporary floater 4 of the second embodiment, the bottom plate 46 suppresses deformation of the underside of the floater body 41, and thus suppresses deformation of the floater body 41. In other words, when buoyancy acts on the temporary floater 4 while it is installed on the floating foundation 3, the buoyancy causes the outer portion of the floater body 41 to rise higher than the inner portion (see Figure 7), but the bottom plate 46 engaged with the floating foundation 3 maintains the horizontality of the underside of the floater body 41, suppressing deformation of the temporary floater 4. Other functions and effects of the temporary floater 4 of the second embodiment are similar to those of the temporary floater 4 of the first embodiment, so detailed explanations will be omitted.

[0024] <Third embodiment> In the third embodiment, as in the first embodiment, a case will be described where a wind power generation facility 1 is constructed. The wind power generation facility 1 is an offshore wind power generation facility, and includes an upper structure 2 and a floating foundation (floating structure) 3 that supports the upper structure 2. The details of the upper structure 2 and the floating foundation 3 are similar to those of the wind power generation facility 1 in the first embodiment, and therefore detailed explanations will be omitted. A temporary floater 4 of the third embodiment is shown in Figure 9. As shown in Figure 9, the temporary floater 4 used in the third embodiment comprises a plurality of hollow floater bodies 41, 41, ... attached to the floating foundation 3, wires 42 for fastening the floater bodies 41 to the floating foundation 3, and a counterweight 47 provided at the upper outer corner of the floater body 41. The configuration of the counterweight 47 is not limited, and it may be, for example, a bag capable of sealing in water and fixed to the upper part of the floater body 41.

[0025] The details of the floater body 41 and the wire 42 are similar to those described in the first embodiment, and therefore a detailed description thereof will be omitted. The counterweight 47 has a weight corresponding to the buoyant force acting on the floater body 41 and is fixed to the upper corner of the floater body 41. The construction method of the temporary floater 4 and the wind power generation facility 1 of the third embodiment is similar to that described in the first embodiment, so a detailed description thereof will be omitted.

[0026] According to the temporary floater 4 of the third embodiment, deformation of the floater body 41 is suppressed by the weight of the counterweight 47. That is, when buoyancy acts on the temporary floater 4 while it is installed on the floating foundation 3, the buoyancy causes the outer part of the floater body 41 to rise higher than the inner part (see FIG. 7), but the weight of the counterweight 47 keeps the top surface of the floater body 41 horizontal, so deformation of the temporary floater 4 is suppressed. Other functions and effects of the temporary floater 4 of the third embodiment are similar to those of the temporary floater 4 of the first embodiment, so detailed explanations will be omitted.

[0027] Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and each of the above-described components can be appropriately modified without departing from the spirit of the present invention. For example, in the embodiment, the floating foundation 3 is of a semi-submersible type, but the structure of the floating foundation 3 is not limited thereto, and it may be of a barge type, for example. Furthermore, the number of side columns 32 constituting the floating foundation 3 is not limited, and may be, for example, three. Furthermore, the support columns 22 of the wind turbine 21 may be erected on the side columns 32.

[0028] In the above embodiment, a case has been described in which a temporary floater 4 is used during the manufacture of the wind power generation facility 1, but the floating structure to which the temporary floater 4 is connected is not limited to the floating foundation 3 of the wind power generation facility 1. In the above embodiment, the wire 42 is divided into the first linear member 43 and the second linear member 44. However, the wire 42 does not necessarily have to be divided. Moreover, the number of divisions of the wire 42 is not limited to two. The material constituting the wire 42 is not limited to wire, but may be, for example, rope, carbon fiber, or a band-shaped (belt-shaped) member.

[0029] In each of the above-mentioned embodiments, deformation of the temporary floater 4 caused by buoyancy is suppressed by installing the deformation prevention member 5, the bottom plate 46, or the counterweight 47, but the deformation suppression method is not limited to the method in each of the above-mentioned embodiments. For example, as shown in Fig. 10, water W may be sealed inside the floater body 41, and deformation of the floater body 41 may be suppressed by the weight of the water. In addition, the wire 42 may be made of a material such as steel that has sufficient rigidity against buoyancy, and the wires 42 may be combined into a frame shape to fix the floater body 41, thereby suppressing deformation of the temporary floater 4. Furthermore, the floater body 41 may be a rigid box body, or may be partially (upper, lower or side) made of a rigid material (e.g., a plate material) to suppress deformation.

[0030] The deformation prevention member 5 may be continuous with the wire 42 . The floater body 41 may be divided into an interior space for sealing air and an interior space for sealing water, and the buoyancy may be adjusted by the amount of water sealed inside. In addition, the buoyancy may be adjusted by the amount of air inside the floater body 41. The arrangement of the floater bodies 41 is not limited, and it is not necessary to arrange a pair of floater bodies 41 so as to face each other with the floating foundation 3 in between. [Explanation of symbols]

[0031] 1. Wind power generation facilities 2 Superstructure 21 Windmill 22 Posts 3. Floating Foundations 31 Center Column 32 Side Column 33 Beam 4 Temporary Floaters 41 Floater body 42 Wire rod 43 First line member 44 Second linear member 45 Connection jig 46 Bottom plate 47 Counterweight 5. Deformation prevention material

Claims

1. A temporary floater for increasing the buoyancy of a floating structure, A plurality of hollow floater bodies attached to the floating structure; A temporary floater, characterized in that it is equipped with a wire for fastening the floater body to the floating structure.

2. 2. A temporary floater as described in claim 1, characterized in that the wires are arranged around the upper, lower and outer surfaces of a pair of floater bodies facing each other with the floating structure in between.

3. 2. A temporary floater as set forth in claim 1, wherein the floater body is a flexible bag body.

4. 4. A temporary floater as described in claim 3, characterized in that a deformation prevention material is provided inside the floater body, extending from the corner between the upper surface and the outer surface to the corner between the lower surface and the inner surface.

5. 2. A temporary floater as described in claim 1, characterized in that the height dimension of the floater body is equivalent to the height dimension of the floating structure at the position where the floater body is attached.

6. 2. A temporary floater as described in claim 1, further comprising a bottom plate extending from the underside of the floater body to the underside of the floating structure.

7. A temporary floater as described in claim 1, characterized in that the wire is formed by connecting a first linear member arranged around the upper, lower and outer surfaces of one of the floater bodies and a second linear member arranged around the upper, lower and outer surfaces of the other floater body, at the upper and lower surfaces of the floating structure.

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