Junction structure and junction method

Abstract

To solve a problem in prior art that is to provide a junction structure and a junction method capable of easily erecting at low cost and ease and capable of alleviating kinetic energy generated when a floating body and a windmill unit are joined in the prior art.SOLUTION: A junction structure between a floating body and a windmill unit composing a floating type offshore wind power generation facility includes: a fitting projection; a fitting hole; and an impact buffer material. Among them, the fitting projection is provided on a bottom unit of the windmill unit, the fitting hole is provided on an apex of the floating body, and the impact buffer material is attached to an inner periphery surface of the fitting hole (or on an outer periphery surface of the fitting projection). When the fitting projection is fitted into the fitting hole, the floating body arranged underwater and the windmill unit arranged above the floating body are joined. Then, the kinetic energy of fitting the fitting projection into the fitting hole is alleviated by the impact buffer material.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an offshore wind power generation facility, and more specifically, to a joining structure between a float and a wind turbine section that can mitigate the kinetic energy generated when joining the float and the wind turbine section, and a method of joining the float and the wind turbine section. [Background technology]

[0002] Although electricity consumption in Japan temporarily began to decline due to the impact of the global financial crisis in 2008, it has been increasing continuously since the oil shock of 1973, expanding 2.6-fold between fiscal 1973 and 2007. The reasons for this include the spread of so-called home appliances such as air conditioners and electric carpets as living standards improve, and the spread of office automation (OA) equipment and communication devices as the number of office buildings increases.

[0003] Until now, this enormous demand for electricity has mainly been met by power generation using so-called fossil fuels such as oil, coal, and natural gas. However, in recent years, attention has been focused on the depletion of fossil fuels and environmental issues associated with global warming, and power generation methods have gradually changed in response. As a result, according to statistics from the Federation of Electric Power Companies of Japan, while the annual amount of electricity generated by oil accounted for about 46% of the total around 1980, by 2010 this proportion had fallen to 9%. Instead, nuclear power generation has increased, accounting for just over 25% of the total (2010). Nuclear power generation has a significant effect on reducing greenhouse gas emissions compared to conventional power generation methods, and can provide electricity at low cost, making it a major contributor to Japan's electricity demand.

[0004] Furthermore, power generation methods using renewable energy sources have come to be adopted due to their ability to reduce greenhouse gas emissions, and in 2020, they accounted for approximately 12% of total annual power generation (Federation of Electric Power Companies). This renewable energy is literally energy that can be reproduced, such as solar, wind, geothermal, small and medium-sized hydroelectric power, and woody biomass, and is seen as a promising source of low-carbon energy as it reduces greenhouse gas emissions and can be produced domestically.

[0005] Among renewable energies, wind power generation has the advantage of high conversion efficiency of electrical energy. In general, the conversion efficiency of solar power generation is about 20%, woody biomass power generation is about 20%, and geothermal power generation is 10-20%, while wind power generation is 20-40%, so it can convert energy into electricity more efficiently than other power generation methods. Another feature of wind power generation is that, unlike solar power generation, it can generate electricity both day and night. Due to these characteristics, wind power generation is already widely used as a major power generation method in Europe, and in Japan, as part of its "energy mix" initiative, it aims to account for 1.7% of the power source mix by 2030.

[0006] Wind power generation can be broadly divided into onshore and offshore wind power generation depending on where it is installed, with onshore wind power generation being easier to install than offshore wind power generation, and therefore having the advantage of being able to keep costs down. On the other hand, offshore wind power generation does not have the noise problems that onshore wind power generation has, and the risk of damage from falling over can be avoided, and above all, it has the advantage of being able to obtain greater wind power stably than on land. Japan, which has the sixth largest exclusive economic zone in the world, is an ideal location for offshore wind power generation, and is thought to have the potential to become a promising producer of renewable energy in the future.

[0007] Also, different types of offshore wind turbines are adopted depending on the installation location, with bottom-fixed offshore wind turbines being suitable for sea areas shallower than 50m, and floating offshore wind turbines being suitable for sea areas deeper than 50m. Of these, floating offshore wind turbines use floats that float on seawater, and generate electricity by installing a power generation mechanism on the float connected by mooring lines. Float types include barge type, semi-submersible type, spar type, and tension leg platform (TLP). Of these, spar type offshore wind turbines are considered advantageous in terms of float manufacturing costs, since the structure of the spar type float is not very complicated, which reduces the labor required for manufacturing, and the spar type float is lightweight, which reduces the material cost.

[0008] FIG. 11 is a side view showing a schematic diagram of a spar-type offshore wind power generation facility. As shown in this figure, a spar-type offshore wind power generation facility is composed of a spar-type float floating in the sea, and a tower, rotor, nacelle, etc. (hereinafter, these are collectively referred to as the "wind turbine unit") installed on the spar-type float. The tower is a structure that supports the rotor and nacelle, and the spar-type float functions as the foundation of the tower. The rotor, which is made up of blades and a hub, converts wind into power, which is then converted into electricity by the nacelle, which includes a gearbox, generator, transformer, etc., and the electricity is transmitted to land via power cables (dynamic cable and undersea cable). Note that spar-type floats are generally moored by the weight of catenary-shaped mooring ropes.

[0009] The main body of the spar-type float is a long body whose axial dimension (hereinafter referred to as "column axis") is larger than its cross-sectional dimension, and has a hollow tubular shape. As shown in Fig. 11, the spar-type float is in a state where its column axis direction is approximately vertical (including vertical) (hereinafter referred to as "upright state") during operation. Normally, this spar-type float is manufactured on land such as in a dry dock, and therefore needs to be transported by sea to the operation area (wind farm area: WF area). Although there are some cases in Northern Europe where the spar-type float is transported in an upright state, in Japan where the water around the land is shallow, the spar-type float is transported with its column axis direction approximately horizontal.

[0010] Meanwhile, the wind turbine section is manufactured separately from the spar-type float and transported to a calm area where it is installed on the spar-type float. At this time, the spar-type float is first set upright as shown in Figure 12, and the wind turbine section, which has also been set upright, is gradually lowered using a crane ship or similar, and then the spar-type float and the wind turbine section are joined. The mainstream method of joining the spar-type float and the wind turbine section is to abut a flange on the top of the spar-type float with a flange on the bottom of the wind turbine section, align the bolt holes of the flanges, and then bolt them together. In addition, the bolt holes are aligned by inserting the guide tubes on the wind turbine section into the guide holes of the spar-type float.

[0011] Incidentally, the spar-type floating body and the wind turbine section (crane ship) in an upright state are prone to swaying such as vertical and horizontal swaying caused by wind and waves even in calm areas, and therefore considerable kinetic energy is generated when one of the floating body and the wind turbine section collides with the other when they are joined. Therefore, various technologies have been proposed to suppress such swaying. For example, Patent Document 1 proposes a technology to suppress swaying by using a ring-shaped member that functions as a "life ring," so to speak, by connecting the ring-shaped member arranged to surround the floating body section with a rope or the like. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] JP 2013-141857 A Summary of the Invention [Problem to be solved by the invention]

[0013] The technology disclosed in Patent Document 1 is a spar-type floating structure capable of suppressing oscillations caused by external forces such as waves and wind, and is intended for spar-type floating structures during operation, but it can also be applied when joining the spar-type floating body to the wind turbine section. However, the technology of Patent Document 1 requires the installation of a complex and delicate structure, which is quite costly when considering the labor, work time, material costs, etc. In addition, measures to suppress the oscillations of the spar-type floating body and the wind turbine section, including those of Patent Document 1, rarely achieve the expected full effect, and therefore, the current situation is that a certain degree of oscillation is accepted when joining the spar-type floating body to the wind turbine section.

[0014] In the past, when joining the spar-type floating body and the wind turbine, it was common to wait until the sea conditions stabilized. However, during the waiting period, naturally, charter fees and labor costs were incurred, and the costs incurred during the waiting period pushed up the overall cost of the construction. Also, sometimes the joining work can be carried out even in an environment where there is some turbulence, but in this case, the guide structure (guide tube and guide hole) mentioned above needs to be made stronger, which means that considerable manufacturing and processing costs are required.

[0015] The object of the present invention is to solve the problems associated with the conventional technology, i.e. to provide a joining structure and joining method that can reduce the kinetic energy generated when joining a floating body and a wind turbine section more effectively than ever before. [Means for solving the problem]

[0016] The present invention was made based on an unprecedented idea that one of the float and the wind turbine section is fitted into the other and shock absorbing material is installed on one of them to reduce the kinetic energy at the time of joining.

[0017] The joining structure of the present invention is a joining structure between a float and a wind turbine unit that constitute a floating offshore wind power generation facility, and includes an insertion convex portion, an insertion hole, and an impact cushioning material. The insertion convex portion is provided at the bottom of the wind turbine unit, the insertion hole is provided at the top of the float, and the impact cushioning material is attached to the inner peripheral surface of the insertion hole (or the outer peripheral surface of the insertion convex portion). When the insertion convex portion is inserted into the insertion hole, the float placed in the sea and the wind turbine unit placed above the float are joined. The impact when the insertion convex portion is inserted into the insertion hole is mitigated by the impact cushioning material.

[0018] The joining structure of the present invention may be such that the fitting protrusion is provided on the top of the floating body and the fitting hole is provided on the bottom of the wind turbine part.

[0019] The joining structure of the present invention may be such that the insertion hole is provided in the bottom of the wind turbine part and the shock absorbing material is attached to the inner peripheral surface of the insertion hole. In this case, the insertion hole has a shape in which the hole diameter increases downward.

[0020] The joining structure of the present invention may be such that the insertion hole is provided at the top of the float and the shock absorbing material is attached to the inner peripheral surface of the insertion hole. In this case, the insertion hole has a shape in which the diameter increases toward the top.

[0021] The joint structure of the present invention may also be one in which a plurality of cylindrical (or columnar) shock absorbers are attached, in which case the plurality of shock absorbers are attached at intervals in the circumferential direction.

[0022] The joining method of the present invention is a method for constructing the joining structure of the present invention, that is, a method for joining a float having an insertion hole at its top and a wind turbine section having an insertion protrusion at its bottom, and includes a float arranging step, a wind turbine section arranging step, and an insertion step. In the float arranging step, the float is arranged in the sea so that it is in a substantially vertical (including vertical) position and a part of it is in the air, and in the wind turbine section arranging step, the wind turbine section is arranged in the air so that it is in a substantially vertical (including vertical) position and above the float. In the insertion step, the wind turbine section is lowered to insert the insertion protrusion into the insertion hole, thereby joining the float and the wind turbine section. In this insertion step, the kinetic energy generated when the insertion protrusion is inserted into the insertion hole is mitigated by the shock absorbing material.

[0023] The joining method of the present invention can also be a method in which the float is raised to fit the fitting protrusion into the fitting hole, thereby joining the float and the wind turbine part.

[0024] The joining method of the present invention can also be a method for joining a float having a fitting protrusion on its top to a wind turbine part having a fitting hole on its bottom. Effect of the Invention

[0025] The joining structure and joining method of the present invention have the following effects. (1) The floating body and the wind turbine unit can be joined together while absorbing kinetic energy, without the need for a rigid structure that requires significant manufacturing or processing costs. (2) Since the joining work can be done even in an environment where there is some degree of swaying, waiting time can be shortened compared to conventional methods, which in turn reduces charter costs, labor costs, etc. incurred during waiting, and reduces the overall cost of the construction. (3) Since shock-absorbing material is attached to the joint between the floating body and the wind turbine unit, unexpected kinetic energy can be mitigated even during operation, meaning that more stable power generation can be continued. [Brief description of the drawings]

[0026] [Figure 1]FIG. 2 is a side view showing the joining structure of the present invention for joining the top of the upright floating body and the bottom of the wind turbine unit. [Diagram 2] FIG. 13 is a perspective view showing a schematic diagram of the state in which the top of the floating body and the bottom of the wind turbine unit are joined together. [Diagram 3] FIG. 4A is a partial side view showing a schematic view of the flange structure as viewed from the side, and FIG. 4B is a plan view showing a schematic view of the flange structure as viewed from above. [Figure 4] 1A is a partial perspective view showing a schematic diagram of a joining structure in which a fitting protrusion is provided at the bottom of the wind turbine section, and FIG. 1B is a partial perspective view showing a schematic diagram of a joining structure in which a fitting protrusion is provided at the top of the floating body. [Diagram 5] 1A is a partial cross-sectional view showing a schematic diagram of a joint structure in which shock-absorbing material is attached to the outer peripheral surface of the insertion protrusion of the wind turbine part, and FIG. 1B is a partial cross-sectional view showing a schematic diagram of a joint structure in which shock-absorbing material is attached to the outer peripheral surface of the insertion protrusion of the floating body. [Figure 6] (a) is a side view of a V-shaped fender, and (b) is a cross-sectional view of the V-shaped fender cut horizontally. [Figure 7] 4 is a plan view showing six shock absorbers attached at equal intervals to the inner peripheral surface of the insertion hole. FIG. [Figure 8] FIG. 1( a ) is a partial cross-sectional view showing a schematic diagram of a joining structure in which an enlarged-diameter insertion hole is provided at the bottom of the wind turbine section, and FIG. 1( b ) is a partial cross-sectional view showing a schematic diagram of a joining structure in which an enlarged-diameter insertion hole is provided at the top of the floating body. [Figure 9] FIG. 4 is a graph showing the results of trial calculations carried out to confirm the effects of the joint structure of the present invention. [Figure 10] 1 is a flow chart showing main steps of a bonding method according to the present invention. [Figure 11] FIG. 2 is a side view showing a schematic diagram of a spar-type floating body having a wind turbine unit attached thereto. [Figure 12] FIG. 1 is a side view showing how a spar-type floating body and a wind turbine unit are joined together using conventional technology. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] An example of an embodiment of a joining structure and a joining method of the present invention will be described with reference to the drawings. The present invention can be particularly suitably carried out when used as a component of a floating offshore wind power generation facility.

[0028] 1.Overview The joining structure 100 of the present invention is a structure at the joint between a floating body 200 and a wind turbine section 300 as shown in FIG. 1, and more specifically, is a structure for joining an upper part (hereinafter referred to as the "top") of the floating body 200 that is held upright in the sea, and a lower part (hereinafter referred to as the "bottom") of the wind turbine section 300 that is also held upright by a crane ship or the like.

[0029] 2 is a perspective view showing a state where the top of the floating body 200 and the bottom of the windmill section 300 are joined. As shown in this figure, the joining structure 100 is configured to include an insertion convex portion 110, an insertion hole 120, and an impact buffer 130. When the insertion convex portion 110 is inserted into the insertion hole 120, the floating body 200 and the windmill section 300 in an upright state are joined. As described above, the floating body 200 and the windmill section 300 in an upright state are prone to shaking due to wind and waves even in a calm area, and when the floating body 200 and the windmill section 300 are joined, one of them collides with the other, generating considerable kinetic energy. Therefore, the joining structure 100 of the present invention is configured to include an impact buffer 130. That is, the shock absorbing material 130 absorbs the kinetic energy when the floating body 200 and the wind turbine section 300 are joined, and as a result, the shocks received by the floating body 200 and the wind turbine section 300 can be absorbed, or at least mitigated.

[0030] In joining the top of the floating body 200 and the bottom of the wind turbine section 300, a conventional flange structure can be used in addition to the joining structure 100. Figure 3 is a diagram showing a typical conventional flange structure, where (a) is a partial side view seen from the side, and (b) is a plan view seen from above. This flange structure is a structure for joining using a lower flange 210 attached to the top of the floating body 200 and an upper flange 310 attached to the bottom of the wind turbine section 300. More specifically, the hole positions of the "lower bolt hole 211" provided in the lower flange 210 and the "upper bolt hole 311" provided in the upper flange 310 are aligned, and then the lower flange 210 and the upper flange 310 are abutted against each other, and the lower bolt hole 211 and the upper bolt hole 311 are sewn together by a bolt. In this case, a "guide tube 312" can be provided on one side (upper flange 310 in FIG. 3) and a "guide hole 212" can be provided on the other side (lower flange 210 in FIG. 3), and a configuration can be adopted in which, when guide tube 312 is inserted into guide hole 212, the hole positions of lower bolt hole 211 and upper bolt hole 311 are aligned. Note that, although two guide holes 212 and guide tubes 312 are used in FIG. 3, this is not limiting, and three or more guide holes 212 and guide tubes 312 can be used.

[0031] 2.Joint structure Next, the joining structure 100 of the present invention will be described in detail with reference to the drawings. The joining method of the present invention is a method of joining a floating body 200 and a wind turbine section 300 using the joining structure 100 of the present invention. Therefore, the joining structure 100 of the present invention will be described first, and then the joining method of the present invention will be described in detail.

[0032] 4A and 4B are partial perspective views showing a joining structure 100 of the present invention, in which (a) shows the joining structure 100 in which an insertion convex portion 110 is provided at the bottom of the wind turbine section 300, and (b) shows the joining structure 100 in which an insertion convex portion 110 is provided at the top of the floating body 200. As shown in FIG. 4A, the joining structure 100 of the present invention can be configured such that an insertion convex portion 110 is provided at the bottom of the wind turbine section 300, an insertion hole 120 is formed at the top of the floating body 200, and an impact buffer 130 is attached to the inner peripheral surface of the insertion hole 120. In this case, the insertion convex portion 110 of the wind turbine section 300 descending from above is inserted into the insertion hole 120 of the floating body 200 while contacting the impact buffer 130, thereby joining the wind turbine section 300 to the floating body 200. The shock absorbers 130 absorb the kinetic energy generated when the floating body 200 and the wind turbine section 300 are joined together, and the reaction force that the floating body 200 receives from the shock absorbers 130 is also mitigated.

[0033] 4(b), the joining structure 100 may be configured such that an insertion convex portion 110 is provided at the top of the float 200, an insertion hole 120 is formed at the bottom of the wind turbine section 300, and an impact buffer 130 is attached to the inner peripheral surface of the insertion hole 120. In this case, the insertion convex portion 110 of the float 200 is inserted into the insertion hole 120 of the wind turbine section 300 that has descended from above while contacting the impact buffer 130, thereby joining the wind turbine section 300 to the float 200. The impact buffer 130 absorbs the kinetic energy when the float 200 and the wind turbine section 300 are joined, and the reaction force that the float 200 receives from the impact buffer 130 is also mitigated.

[0034] The fitting protrusion 110 can be formed in a generally columnar shape (for example, a cylindrical shape), and the fitting hole 120 can be shaped to accommodate the fitting protrusion 110. The fitting protrusion 110 is fitted into the fitting hole 120 to which the shock absorbing material 130 is attached, and therefore has a smaller diameter than the fitting hole 120. Furthermore, the tip of the fitting protrusion 110 may be formed in a curved shape so that the fitting protrusion 110 can be smoothly fitted into the fitting hole 120. For example, the fitting protrusion 110 shown in FIG. 4(a) has a curved shape that narrows in diameter from top to bottom, and the fitting protrusion 110 shown in FIG. 4(b) has a curved shape that narrows in diameter from bottom to top.

[0035] The joint structure 100 shown in Fig. 4 is configured such that the shock absorbing material 130 is attached to the inner circumferential surface of the fitting hole 120, but instead, it can be configured such that the shock absorbing material 130 is attached to the outer circumferential surface of the fitting protrusion 110 as shown in Fig. 5. Fig. 5 is a partial cross-sectional view showing a schematic diagram of the joint structure 100, in which (a) shows the joint structure 100 in which the shock absorbing material 130 is attached to the outer circumferential surface of the fitting protrusion 110 of the wind turbine section 300, and (b) shows the joint structure 100 in which the shock absorbing material 130 is attached to the outer circumferential surface of the fitting protrusion 110 of the floating body 200.

[0036] The shock absorber 130 can be formed using various conventional materials, for example, conventional fenders, as long as they can absorb the kinetic energy when the floating body 200 and the wind turbine unit 300 are joined. FIG. 6 shows a so-called V-shaped fender with a V-shaped cross section, where (a) shows a side view from the side and (b) shows a cross section cut on a horizontal plane. The shock absorber 130 shown in this figure is formed to include a contact plate 131 and a collision part 132, and the collision part 132 is partially or entirely hollow in the axial direction, that is, formed as a cylinder. In this case, the shock absorber 130 is attached to the insertion hole 120 (or the insertion protrusion 110) with the contact plate 131 in contact with the inner peripheral surface of the insertion hole 120 (or the outer peripheral surface of the insertion protrusion 110), and the collision part 132 absorbs the shock from the wind turbine unit 300 (or the floating body 200).

[0037] A plurality of shock absorbers 130 can be attached to the inner peripheral surface of the insertion hole 120 or the outer peripheral surface of the insertion protrusion 110. In this case, it is preferable to attach the shock absorbers 130 at intervals in the circumferential direction of the inner peripheral surface of the insertion hole 120 or the outer peripheral surface of the insertion protrusion 110. For example, in FIG. 7, six shock absorbers 130 using V-shaped fenders are attached to the inner peripheral surface of the insertion hole 120, and each shock absorber 130 is arranged so that the central angle is 60 degrees. Of course, two or more shock absorbers 130 can be attached, and multiple shock absorbers 130 can be attached at unequal intervals. Also, for example, only one wide shock absorber 130 that covers the entire inner peripheral surface of the insertion hole 120 can be attached.

[0038] Thus far, an example has been described in which the joint structure 100 is configured to include the fitting protrusion 110, the fitting hole 120, and the shock-absorbing material 130, but the joint structure 100 of the present invention can also be configured to include the fitting hole 120 and the shock-absorbing material 130. Fig. 8 is a partial cross-sectional view showing a schematic diagram of the joint structure 100 (hereinafter referred to as "expansion-type joint structure 100") that includes the fitting hole 120 and the shock-absorbing material 130, in which (a) shows the joint structure 100 in which the fitting hole 120 is provided in the bottom of the wind turbine section 300, and (b) shows the joint structure 100 in which the fitting hole 120 is provided in the top of the floating body 200.

[0039] The fitting hole 120 of the expanding joint structure 100 has a shape in which the hole diameter becomes larger toward the tip. For example, the fitting hole 120 shown in FIG. 8(a) has a shape in which the hole diameter becomes larger toward the bottom, and the fitting hole 120 shown in FIG. 8(b) has a shape in which the hole diameter becomes larger toward the top. In the example of FIG. 8(a), the top of the floating body 200 is fitted into the fitting hole 120, and in the example of FIG. 8(b), the bottom of the wind turbine unit 300 is fitted into the fitting hole 120. Therefore, a space capable of accommodating the top of the floating body 200 and the bottom of the wind turbine unit 300 is formed in the fitting hole 120 of the expanding joint structure 100. Note that the fitting hole 120 shown in FIG. 8 has a curved inner circumferential surface, but is not limited thereto and may have a shape in which the diameter is linearly expanded.

[0040] In the case of the expanding type joining structure 100 shown in Fig. 8(a), the top of the floating body 200 is fitted into the fitting hole 120 of the wind turbine section 300 that has descended from above while contacting the shock absorber 130. This joins the wind turbine section 300 to the floating body 200. The shock absorber 130 absorbs the kinetic energy generated when the floating body 200 and the wind turbine section 300 are joined, and the reaction force that the floating body 200 receives from the shock absorber 130 is also mitigated.

[0041] On the other hand, in the case of the expanding type joining structure 100 shown in FIG. 8(b), the bottom of the wind turbine section 300 descending from above is fitted into the fitting hole 120 of the float 200 while contacting the shock absorber 130, and the wind turbine section 300 is joined to the float 200. The shock absorber 130 absorbs the kinetic energy when the float 200 and the wind turbine section 300 are joined, and the reaction force that the float 200 receives from the shock absorber 130 is also mitigated. In FIG. 8(a), the shock absorber 130 is attached to the inner peripheral surface of the fitting hole 120, but this is not limited to this, and it can also be attached to the outer peripheral surface near the top of the float 200, and similarly, in FIG. 8(b), it can also be attached to the outer peripheral surface near the bottom of the wind turbine section 300. In addition, two or more shock absorbers 130 can be attached at intervals in the circumferential direction, or only one wide shock absorber 130 can be attached.

[0042] The inventors of the present invention performed trial calculations based on predetermined conditions to confirm the effect of the joint structure 100 of the present invention. In this trial calculation, the conditions set as realistic working environments for attaching the wind turbine unit 300 to the floating body 200 are a significant wave height of 0.7 m, a significant frequency of 6.0 seconds, and a relative oscillation amount of 50 cm between the floating body 200 and the wind turbine unit 300 at this time, and calculated the kinetic energy of 700 kJ when the wind turbine unit 300 and the floating body 200 collide. FIG. 9 shows the result of the trial calculation when a general-purpose fender "V-type 1000H x 2500L" is used as the shock buffer 130. As shown in this figure, the shock buffer 130 to which kinetic energy of 700 kJ is applied absorbs the kinetic energy at a compression rate of about 45%. Furthermore, the reaction force acting on the floating body 200 from the shock absorbers 130 at this time is 2000 kN, which is a reaction force that the floating body 200 can fully withstand. In other words, it was confirmed that, even if the work of attaching the wind turbine section 300 to the floating body 200 is performed in a tolerable oscillation environment within a realistic range, the use of the joining structure 100 of the present invention makes it possible to join the floating body 200 and the wind turbine section 300 without causing any particular problems.

[0043] 3.Joining method Next, the joining method of the present invention will be described in detail with reference to Fig. 10. Note that the joining method of the present invention is a method for joining the floating body 200 and the wind turbine section 300 using the joining structure 100 described so far, and therefore, we will avoid any explanation that overlaps with the contents explained in the joining structure 100, and will only explain the contents unique to the joining method of the present invention. In other words, the contents not described here are the same as those explained in "2. Joining structure".

[0044] Fig. 10 is a flow diagram showing the main steps of the joining method of the present invention. As shown in this figure, when joining the floating body 200 and the wind turbine unit 300 using the joining structure 100, first, the floating body 200 is manufactured in a dry dock or the like (Step 401 in Fig. 10). Then, during a period when the environment is favorable in terms of tide levels and currents, the floating body 200 in a sideways state is towed by a tugboat or the like to a calm area selected in advance (Step 402 in Fig. 10), and the floating body 200 is temporarily moored there. Meanwhile, the wind turbine unit 300 is manufactured separately from the floating body 200 (Step 403 in Fig. 10), and is also transported to the calm area by a tugboat or the like (Step 403 in Fig. 10).

[0045] When the floating body 200 and the wind turbine unit 300 are transported to a calm area, the floating body 200 is raised in the sea and brought into an upright state with a part of it in the air (Step 405 in FIG. 10). The wind turbine unit 300 is then lifted up by a crane ship or the like, so that it is brought into an upright state so that it is located above the floating body 200 (Step 406 in FIG. 10). The crane ship or the like then gradually lifts down the wind turbine unit 300, and the wind turbine unit 300 is lowered as it is, and the fitting protrusion 110 is fitted into the fitting hole 120, thereby joining the floating body 200 and the wind turbine unit 300 (Step 407 in FIG. 10). Alternatively, the wind turbine section 300 can be hoisted down to near the top of the float 200 using a crane ship or the like, and then the float 200 can be raised, whereby the fitting protrusion 110 can be fitted into the fitting hole 120 to join the float 200 and the wind turbine section 300. The float 200 can be raised, for example, by discharging ballast water from within the float 200. As described above, at this time, the top of the float 200 and the bottom of the wind turbine section 300 can be joined by using a conventional flange structure. The kinetic energy generated when the fitting protrusion 110 is fitted into the fitting hole 120 is absorbed by the shock absorbing material 130, and as a result, the shock that the float 200 and the wind turbine section 300 receive can be mitigated. [Industrial Applicability]

[0046] The joining structure and joining method of the present invention are particularly suitable for use in floating offshore wind power generation in sea areas 50m or deeper. The present invention can be expected to provide a more positive incentive for offshore wind power generation, as it can install floating offshore wind power generation facilities at low cost by shortening standby time. Furthermore, considering the need to provide a stable supply of energy while reducing greenhouse gas emissions, the present invention can be said to be an invention that can be expected to not only be used industrially, but also to make a significant contribution to society. [Explanation of symbols]

[0047] 100 Joint structure of the present invention 110 (of joint structure) fitting protrusion 120 (Joint structure) insertion hole 130 (Jointed) shock absorbing material 131 (Shock absorbing material) contact plate 132 (Shock absorbing material) collision part 200 Floating Body 210 (floor) lower flange 211 (Lower flange) lower bolt hole 212 (Lower flange) guide hole 300 Windmill section 310 (Windmill section) Upper flange 311 (Upper flange) Upper bolt hole 312 (Upper flange) guide tube

Claims

1. A joint structure between a float and a wind turbine unit constituting a floating offshore wind power generation facility, A fitting protrusion provided on a bottom of the wind turbine unit; An insertion hole provided at the top of the float; a shock absorbing material attached to an inner peripheral surface of the insertion hole or an outer peripheral surface of the insertion protrusion, When the fitting protrusion is fitted into the fitting hole, the float disposed in the sea and the wind turbine unit disposed above the float are joined together, The impact generated when the fitting protrusion is fitted into the fitting hole is mitigated by the impact cushioning material. A joining structure characterized by:

2. A joint structure between a float and a wind turbine unit constituting a floating offshore wind power generation facility, An insertion hole provided at a bottom of the wind turbine unit; A fitting protrusion provided on the top of the float; a shock absorbing material attached to an inner peripheral surface of the insertion hole or an outer peripheral surface of the insertion protrusion, When the fitting protrusion is fitted into the fitting hole, the float disposed in the sea and the wind turbine unit disposed above the float are joined together, The impact generated when the fitting protrusion is fitted into the fitting hole is mitigated by the impact cushioning material. A joining structure characterized by:

3. A joint structure between a float and a wind turbine unit constituting a floating offshore wind power generation facility, An insertion hole provided at a bottom of the wind turbine unit; An impact cushioning material attached to an inner circumferential surface of the insertion hole, The insertion hole has a diameter that increases downward, When the top of the float is inserted into the insertion hole, the float disposed in the sea and the wind turbine unit disposed above the float are joined together, The impact when the top of the float is inserted into the insertion hole is mitigated by the impact cushioning material. A joining structure characterized by:

4. A joint structure between a float and a wind turbine unit constituting a floating offshore wind power generation facility, An insertion hole provided at the top of the float; An impact cushioning material attached to an inner circumferential surface of the insertion hole, The insertion hole has a hole diameter that expands upward, When the bottom of the wind turbine unit is inserted into the insertion hole, the floating body disposed in the sea and the wind turbine unit disposed above the floating body are joined together, The impact when the bottom of the wind turbine unit is inserted into the insertion hole is mitigated by the impact cushioning material. A joining structure characterized by:

5. A plurality of cylindrical or columnar shock absorbing materials are attached at intervals in the circumferential direction. The joint structure according to any one of claims 1 to 4.

6. A method for joining a float and a wind turbine unit that constitute a floating offshore wind power generation facility, comprising the steps of: A fitting protrusion is provided on the bottom of the wind turbine unit, The float has an insertion hole at its top, A shock absorbing material is attached to an inner peripheral surface of the insertion hole or an outer peripheral surface of the insertion protrusion, a float placement step of placing the float in the sea in a vertical or approximately vertical position with a portion of the float being in the air; a wind turbine unit arrangement step of arranging the wind turbine unit in the air so as to be in a vertical or approximately vertical position and above the floating body; and an insertion step of lowering the wind turbine part and inserting the insertion protrusion into the insertion hole to join the floating body and the wind turbine part, In the fitting step, an impact occurring when the fitting protrusion is fitted into the fitting hole is mitigated by the impact cushioning material. A bonding method comprising the steps of:

7. A method for joining a float and a wind turbine unit that constitute a floating offshore wind power generation facility, comprising the steps of: A fitting protrusion is provided on the bottom of the wind turbine unit, The float has an insertion hole at its top, A shock absorbing material is attached to an inner peripheral surface of the insertion hole or an outer peripheral surface of the insertion protrusion, a float placement step of placing the float in the sea in a vertical or approximately vertical position with a portion of the float being in the air; a wind turbine unit arrangement step of arranging the wind turbine unit in the air so as to be in a vertical or approximately vertical position and above the floating body; and an insertion step of joining the float and the wind turbine unit by raising the float and inserting the insertion protrusion into the insertion hole, In the fitting step, an impact occurring when the fitting protrusion is fitted into the fitting hole is mitigated by the impact cushioning material. A bonding method comprising the steps of:

8. A method for joining a float and a wind turbine unit that constitute a floating offshore wind power generation facility, comprising the steps of: An insertion hole is provided at the bottom of the wind turbine unit, The float is provided with a fitting protrusion at its top, A shock absorbing material is attached to an inner peripheral surface of the insertion hole or an outer peripheral surface of the insertion protrusion, a float placement step of placing the float in the sea in a vertical or approximately vertical position with a portion of the float being in the air; a wind turbine unit arrangement step of arranging the wind turbine unit in the air so as to be in a vertical or approximately vertical position and above the floating body; and an insertion step of lowering the wind turbine part and inserting the insertion protrusion into the insertion hole to join the floating body and the wind turbine part, In the fitting step, a movement impact when the fitting protrusion is fitted into the fitting hole is mitigated by the impact cushioning material. A bonding method comprising the steps of:

9. A method for joining a float and a wind turbine unit that constitute a floating offshore wind power generation facility, comprising the steps of: An insertion hole is provided at the bottom of the wind turbine unit, The float is provided with a fitting protrusion at its top, A shock absorbing material is attached to an inner peripheral surface of the insertion hole or an outer peripheral surface of the insertion protrusion, a float placement step of placing the float in the sea in a vertical or approximately vertical position with a portion of the float being in the air; a wind turbine unit arrangement step of arranging the wind turbine unit in the air so as to be in a vertical or approximately vertical position and above the floating body; and an insertion step of joining the float and the wind turbine unit by raising the float and inserting the insertion protrusion into the insertion hole, In the fitting step, a movement impact when the fitting protrusion is fitted into the fitting hole is mitigated by the impact cushioning material. A bonding method comprising the steps of:

Images