Floating offshore wind farm

Abstract

To achieve significant reduction of the number of work days and provide an efficient construction method on land by utilizing techniques cultivated in construction work of a skyscraper etc. to build a floating offshore wind farm, launching the floating offshore wind farm assembled on land, and towing the floating offshore wind farm to a work side by a tugboat.SOLUTION: A tower part disposed on the ocean and a buoyancy body part disposed in water are built by reinforced-concrete structures, the tower part and the buoyancy body part are connected by a plurality of pillars, and a floating offshore wind farm is moored to a plurality of seabed foundation piles fixed to the seabed by a plurality of mooring wires. The floating offshore wind farm is provided to achieve the above object.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a floating offshore wind power plant with a reinforced concrete structure.

Background Art

[0002] In recent years, with the increasing use of renewable energy, since there are no obstacles to block the wind on the ocean and the wind direction and wind speed are constant and do not change, it is expected that stable power can be obtained from offshore wind power generation. Currently, the structure of the offshore wind power generation device that has been put into practical use is the same as that of the device operating on land. Since there are fewer restrictions on installing the wind power generation device on the ocean compared to on land, it is considered that the installation on the ocean will increase in the future.

[0003] Currently, in the case of the fixed-bottom type where the support column of the offshore wind power generation device popular in Europe reaches the seabed, it is suitable for relatively shallow water areas with a water depth of about 50 m or less. However, in the case of Japan, since the area of the continental shelf with a relatively shallow water depth is small, in Japan, the situation is that the wind power generation device is being shifted to a floating type that floats on the ocean and maintains its position by being moored to the seabed with chains, wire ropes, etc.

[0004] The floating offshore wind power generation device is composed of a floating body arranged in water and a tower part erected on the floating body, and is equipped with a wind power generation device composed of a nacelle and blades at the top of the tower part. The methods for mooring the floating offshore wind power generation device to the seabed mainly include four types: the spar type, the semi-submersible type, the barge type, and the TLP type.

[0005] Currently, an increase in the output per unit of equipment is required, and accordingly, it is necessary to lengthen the blades to increase the windward area of the wind turbine body. Currently, large-scale offshore wind power generation devices with blade lengths exceeding 80 m are being put into practical use.

[0006] Conventionally, in order to install a floating offshore wind power generation device in a designated sea area, after towing and mooring the floating body to the installation sea area by a mother ship or the like, the upper structure is moved to the upper end of the floating body by a crane ship or the like, and the floating body and the upper structure are connected.

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in sea areas with a water depth of 50 m or more where floating offshore wind power generation devices are installed, the sea state conditions are often more severe than those in sea areas where general marine construction is carried out. Since the installation work of floating offshore wind power generation devices must be carried out taking into account relatively calm periods under severe sea state conditions, there has been a problem that the implementation time and period of the installation work are limited.

[0008] Furthermore, since the installation of floating offshore wind power generation devices requires delicate work using large workboats, there has also been a problem of increasing construction costs.

[0009] In view of the above situation, the present invention constructs facilities for building a floating offshore wind power plant on the coast near the sea where the floating offshore wind power plant is to be installed, and utilizes the technology cultivated in building construction such as super high-rise buildings to build a floating offshore wind power plant. The floating offshore wind power plant assembled on land is floated on the water and towed to the site by a tugboat (towboat) or the like, aiming to significantly shorten the construction days and provide an efficient construction method on land.

Means for Solving the Problems

[0010] In order to solve such problems, the invention according to claim 1 is a floating offshore wind power generation composed of a tower that supports a nacelle incorporating a plurality of blades, a speed increaser, and a generator. The tower part arranged offshore and the buoyancy body part arranged underwater are constructed with a reinforced concrete structure, and the tower part and the buoyancy body part are connected by a plurality of columns. Further, it is characterized in that it is moored to a plurality of submarine foundation piles fixed to the seabed by a plurality of mooring wires.

[0011] In addition to the structure described in claim 1, the invention according to claim 2 is characterized in that the tower part is generally conical and the lower part is composed of a multi-story building, and the top part is formed with a circular plane, and a steel pipe for attaching a nacelle is attached to the top part.

[0012] In addition to the structure described in claim 1 or 2, the invention according to claim 3 is characterized in that the buoyancy body part is generally cylindrical and the inside is hollow, and in order to float a floating type offshore wind power plant constructed on land near the sea on the water, the bottoms in both the front direction and the rear direction are inclined toward the front end part and the rear end part.

[0013] In addition to the structure described in any one of claims 1 to 3, the invention according to claim 4 is characterized in that the buoyancy body part is connected by a plurality of subsea foundation piles installed on the seabed and a plurality of mooring wires and moored in a TLP type, and one ends of the plurality of mooring wires passing through mooring wire guide holes formed on the side surface of the buoyancy body part are drawn into the building of the tower part via a plurality of wire pulleys, and the horizontal state of the floating type offshore wind power plant is maintained by adjusting the individual lengths of the mooring wires with a wire winding / sending machine.

[0014] In addition to the structure described in any one of claims 1 to 4, the invention according to claim 5 is characterized in that a vertical hole partition penetrating from generally the upper end part of the tower part to generally the lower end part of the buoyancy body part is constructed, and a simple lift and stairs for vertical movement are installed inside the vertical hole partition.

Advantages of the Invention

[0015] According to the invention described in claim 1, in a floating offshore wind power generation composed of a plurality of blades, a speed increaser or a generator, and a tower supporting a nacelle, a tower part arranged offshore and a buoyancy body part arranged underwater are constructed with a reinforced concrete structure. Further, the tower part and the buoyancy body part are connected by a plurality of columns, and are moored to a plurality of submarine foundation piles fixed to the seabed by a plurality of mooring wires. By utilizing the technology cultivated in construction work such as super high-rise buildings, the manufacturing days can be significantly shortened and the construction cost can be reduced.

[0016] According to the invention described in claim 2, the tower part is generally conical and the lower part is composed of a multi-story building, and the top part is formed with a circular plane. By attaching a steel pipe for attaching a nacelle to the top part, it can be utilized as a dwelling for workers for maintenance and inspection, and the wind pressure of the wind on the tower part can be reduced.

[0017] According to the invention described in claim 3, the buoyancy body part is generally cylindrical and the inside is hollow. In order to float a floating offshore wind power plant constructed on land near the sea on the water, the bottoms in both the front and rear directions are inclined toward the front end part and the rear end part, so that the water resistance can be reduced and it can float on the water in a stable state.

[0018] According to the invention described in claim 4, the buoyancy body part is connected by a plurality of submarine foundation piles installed on the seabed and a plurality of mooring wires and moored in a TLP type. One end of the plurality of mooring wires passing through the mooring wire guide holes formed on the side surface of the buoyancy body part is drawn into the building of the tower part via a plurality of wire pulleys, and the individual lengths of the mooring wires are adjusted by a wire winding / sending machine. By configuring it to maintain the horizontal state of the floating offshore wind power plant, the lengths of the individual mooring wires can be adjusted, and the floating offshore wind power plant can be maintained horizontally with respect to the sea surface.

[0019] According to the invention described in claim 5, by constructing a vertical hole partition that penetrates from approximately the upper end of the tower part to approximately the lower end of the buoyancy body part, and installing a simple lift and a staircase for vertical movement inside the vertical hole partition, it becomes possible to significantly reduce the labor for maintenance and inspection by workers.

Embodiment

[0020] Hereinafter, embodiments of the present invention will be described.

Mode for Carrying Out the Invention

[0021] Figs. 1 to 7 show embodiments of the present invention.

[0022] Figure 1 shows a perspective view of the floating offshore wind power plant 1 of the present invention installed offshore. The floating offshore wind power plant 1 includes three blades 2 with a length of about 80 m attached to the hub 10, a speed increaser, a generator, a yaw control device, etc. installed inside the nacelle 3, a steel pipe 23 for fixing the nacelle 3 to the tower section 4, a tower section 4 constructed with a reinforced concrete structure, and eight struts 6 formed of steel pipes with a diameter of about 2 m, a wall thickness of about 30 mm, and a length of about 10 m for connecting the tower section 4 and the buoyancy body section 8. Further, the floating offshore wind power plant 1 is floated and made self-supporting offshore, and is composed of a buoyancy body section 8 with a hollow interior formed of a reinforced concrete structure to serve as a floating structure section. In order to suppress the sway of the buoyancy body section 8 configured in this way as much as possible, six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, mooring wire (F) 16 are used to moor it to the seabed 9 in a TLP type. And, in order to fix the six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, mooring wire (F) 16 to the seabed 9, it is composed of six seabed foundation piles (A) 17, seabed foundation pile (B) 18, seabed foundation pile (C) 19, seabed foundation pile (D) 20, seabed foundation pile (E) 21, seabed foundation pile (F) 22 fixed to the seabed 9. The electricity generated by the floating offshore wind power plant 1 configured in this way is sent to an onshore substation (not shown) via a submarine power transmission cable 24 laid on the seabed 9 and then connected to the transmission line of the onshore general power system. Note that since the nacelle 3 attached to the steel pipe 23 needs to always face the blade 2 against the direction of the blowing wind, a yaw control device (not shown) is attached inside the nacelle 3 so that it can be rotated 360 degrees with respect to the steel pipe 23.

[0023] Figure 2 shows a front view of the floating offshore wind power plant 1 described in Figure 1. In the present invention, in order to moor the floating offshore wind power plant 1 in a TLP type to the seabed 9, six seabed foundation piles fixed to the seabed 9, namely, seabed foundation pile (A) 17, seabed foundation pile (B) 18, seabed foundation pile (C) 19, seabed foundation pile (D) 20, seabed foundation pile (E) 21, and seabed foundation pile (F) 22, are respectively attached with six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16. The lengths of the six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16 are adjusted by the wire pulley (B) 62, wire pulley (A) 61, and wire winding and feeding machine 60 described in Figure 7 so that the position of the sea surface 7 is approximately at the vertical center position of the support column 6, and the floating body part 8 is forcibly submerged to keep horizontal with respect to the sea surface 7, so that the floating offshore wind power plant 1 can greatly suppress pitching and rolling with respect to the sea surface 7 and maintain a horizontal state, and the blade 2 can be rotated in a stable state with respect to the wind.

[0024] Figure 3 shows the tower section 4, the support column 6, and the buoyancy body section 8 described in FIGS. 1 and 2 in a plan view of FIG. 3a and a front view of FIG. 3b. The tower section 4 is constructed of a generally conical reinforced concrete structure. The top part 33 is formed in a circular shape with a diameter of approximately 5 m as shown by the upper tower diameter A in FIG. 6. The thickness of the upper tower slab B is approximately 500 mm. The tower height C from the top part 33 of the tower section 4 to the tower bottom 39 is approximately 97 m. The tower bottom slab thickness D that constitutes the tower base 40 of the tower section 4 is approximately 1 m. The tower base diameter S that constitutes the tower base 40 of the tower section 4 is circular with a diameter of approximately 25 m. A building 5 with a four-story structure (shown as the first floor 38 of the building, the second floor 37 of the building, the third floor 36 of the building, and the fourth floor 35 of the building) where the height of each floor is approximately 5 m is constructed at the lower part of the tower section 4. The buoyancy body section 8 is generally cylindrical and has a hollow interior to serve as a floating body for floating the floating offshore wind power plant 1 on the ocean. As shown in FIG. 6, the buoyancy body diameter N of the buoyancy body section 8 is approximately 100 m, and the buoyancy body height J is approximately 10 m. Further, as shown in FIG. 3, in order to float the floating offshore wind power plant 1 constructed on land on the water in a stable state in both the front and rear directions of the bottom surface of the buoyancy body section 8, the bottom parts in both the front and rear directions are inclined at an angle of approximately 14 degrees as shown by the front inclination part 31 (the boundary between the bottom and the front inclination part 31 is shown by the dashed-dotted line (A) 41 in FIG. 3a) and the rear inclination part 32 (the boundary between the bottom and the rear inclination part 32 is shown by the dashed-dotted line (B) 42 in FIG. 3a) toward the tip and the rear end, as shown by the front inclination angle M and the rear inclination angle R in FIG. 6. Further, a state where the tower section 4 and the buoyancy body section 8 are connected by eight support columns 6 formed of steel pipes with a diameter of approximately 2 m, a wall thickness of approximately 30 mm, and a length of approximately 10 m is shown.

[0025] Furthermore, on the side surface of the buoyancy body portion 8, six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16 described in FIGS. 1 and 2 are guided at fixed positions on the side surface of the buoyancy body portion 8. Therefore, six mooring wire guide holes (A) 25, mooring wire guide holes (B) 26, mooring wire guide holes (C) 27, mooring wire guide holes (D) 28, mooring wire guide holes (E) 29, and mooring wire guide holes (F) 30, each formed in a substantially semi-cylindrical shape (kamaboko shape) with a radius of about 30 cm, are formed vertically at positions on the side surface of the buoyancy body portion 8 that extend radially from the center at 60-degree intervals when viewed in the horizontal plane of the upper surface of the buoyancy body portion 8.

[0026] Furthermore, a vertical hole section 34 is constructed that penetrates generally from the top portion 33 to the bottom portion 39 of the tower portion 4 and extends to approximately the bottom of the center portion of the buoyancy body portion 8, and is formed in a generally cylindrical shape with a diameter of about 4 m as shown by the dashed-dotted line (C) 43. Additionally, by installing a staircase for vertical movement (not shown) and a simple lift (not shown) for inspection work inside the vertical hole section 34, it has become possible to improve work efficiency.

[0027] FIG. 4 shows the support column 6 and the buoyancy body portion 8 described in FIGS. 1 and 2 in a plan view of FIG. 4a and a front view of FIG. 4b. Six mooring wire guide holes (A) 25, mooring wire guide holes (B) 26, mooring wire guide holes (C) 27, mooring wire guide holes (D) 28, mooring wire guide holes (E) 29, and mooring wire guide holes (F) 30 formed on the outer peripheral portion of the buoyancy body portion 8 are formed vertically at positions on the side surface of the buoyancy body portion 8 that extend radially from the center at 60-degree intervals when viewed in the horizontal plane of the upper surface of the buoyancy body portion 8. The shapes of the mooring wire guide holes (A) 25, mooring wire guide holes (B) 26, mooring wire guide holes (C) 27, mooring wire guide holes (D) 28, mooring wire guide holes (E) 29, and mooring wire guide holes (F) 30 are all formed in a substantially semi-cylindrical shape (kamaboko shape) with a radius of about 30 cm.

[0028] Furthermore, the eight columns 6 for connecting the tower section 4 and the buoyancy body section 8 are all formed of cylindrical steel pipes with a diameter of approximately 2 m, a wall thickness of 30 mm, and a length of 10 m. The eight columns (A) 45, column (B) 46, column (C) 47, column (D) 48, column (E) 49, column (F) 50, column (G) 51, and column (H) 52 are vertically attached so that their centers are located at positions radially extending every 45 degrees from the center on the circumference with a radius of approximately 1050 cm from the center of the upper surface of the buoyancy body section 6 when viewed in the horizontal plane. Moreover, the upper parts of the eight columns (A) 45, column (B) 46, column (C) 47, column (D) 48, column (E) 49, column (F) 50, column (G) 51, and column (H) 52 are attached to the lower surface of the tower bottom 39 described in FIG. 3. The reason for connecting the tower section 4 and the buoyancy body section 8 with the eight columns 6 in this way is to minimize the resistance caused by the waves on the sea surface and suppress the sway of the floating offshore wind power plant 1 by supporting the tower section 4 with the cylindrical round columns.

[0029] Figure 5 shows six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16 for mooring the buoyancy body 8 described in FIGS. 1 and 2 to the seabed 9, as shown in the plan view of FIG. 5a and the front view of FIG. 5b. The six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16 are passed through six mooring wire guide holes (A) 25, mooring wire guide hole (B) 26, mooring wire guide hole (C) 27, mooring wire guide hole (D) 28, mooring wire guide hole (E) 29, and mooring wire guide hole (F) 30 formed vertically on the side surface of the buoyancy body 8. For each individual mooring wire, a wire pulley (B) 62, a wire pulley (A) 61, and a wire winding / sending machine 60 shown in FIG. 7 are used to adjust the length so that the sea surface 7 described in FIG. 2 is approximately at the vertical center position of the support column 6. In this way, the horizontal state of the floating offshore wind power plant 1 can be easily maintained. The positional relationship between the six mooring wire guide holes (A) 25, mooring wire guide hole (B) 26, mooring wire guide hole (C) 27, mooring wire guide hole (D) 28, mooring wire guide hole (E) 29, mooring wire guide hole (F) 30 and the six subsea foundation piles (A) 17, subsea foundation pile (B) 18, subsea foundation pile (C) 19, subsea foundation pile (D) 20, subsea foundation pile (E) 21, subsea foundation pile (F) 22 is such that in order to minimize the sway of the buoyancy body 8 caused by ocean currents and waves, the six subsea foundation piles (A) 17, subsea foundation pile (B) 18, subsea foundation pile (C) 19, subsea foundation pile (D) 20, subsea foundation pile (E) 21, subsea foundation pile (F) 22 are fixed to the seabed directly below the six mooring wire guide holes (A) 25, mooring wire guide hole (B) 26, mooring wire guide hole (C) 27, mooring wire guide hole (D) 28, mooring wire guide hole (E) 29, mooring wire guide hole (F) 30. This makes it possible to suppress the occupied area below the sea surface, which is one of the characteristics of the TLP type.

[0030] Figure 6 shows the dimensions and angles of the members of the tower part 4, the support columns 6, and the buoyancy body part 8 described in FIGS. 1 and 2 using symbols A to S. The tower part 4 is generally conical, and the top part 33 is formed as a circular plane. The diameter A of the upper part of the tower part at the top part 33 is formed as a circle with a diameter of about 5 m. Further, the slab thickness B of the upper part of the tower part at the top part 33 is formed to be about 500 mm. Further, as shown by the dashed line (C) 43, the vertical hole section 34 penetrates from the generally upper end of the tower part 33 through the tower base 40 to the generally lower end of the buoyancy body part 8 and is formed as a cylindrical shape with a diameter of about 4 m and a length of about 116.3 m. Further, the height C of the tower part from the top part 33 to the bottom of the tower 39 of the tower part 4 is formed to be about 97 m. Further, for the four-story building 5, the height F of the fourth floor of the building is about 5 m, the height G of the third floor of the building is about 5 m, the height H of the second floor of the building is about 5 m, and the height I of the first floor of the building is about 5 m. Further, the slab thickness D of the bottom of the tower at the bottom of the tower part 4 is formed to be about 1 m, and the diameter S of the tower base of the lower part of the tower part 4 is formed as a circle with a diameter of about 25 m. Further, the height E of all eight support columns 6 is formed to be about 10 m. Further, the thickness of the outer skin on the outer peripheral surface, upper and lower surfaces of the reinforced concrete of the buoyancy body part 8 constructed with a reinforced concrete structure is formed to be about 200 mm for both the upper part, lower part, and outer peripheral surface. Further, the front and rear bottoms of the buoyancy body part 8 are formed in a shape inclined forward and backward. Further, the diameter N of the buoyancy body part of the buoyancy body part 8 is formed as a cylindrical shape with a diameter of about 100 m. Further, the height J of the buoyancy body part excluding the front inclined part 31 and the rear inclined part 32 of the buoyancy body part 8 described in FIG. 3 is formed to be about 10 m. Further, the height K of the tip of the front inclined part of the front inclined part 31 and the height R of the rear end of the rear inclined part of the rear inclined part 32 of the buoyancy body part 8 described in FIG. 3 are both formed to be about 3 m. Further, the front inclined part angle M and the rear inclined part angle P of the front inclined part 31 and the rear inclined part 32 described in FIG. 3 are both formed to be about 14 degrees with respect to the bottom surface. The maximum width L of the front inclined part of the front inclined part 31 and the maximum width Q of the rear inclined part of the rear inclined part 32 are both formed to be about 12 m. In this way, by constructing the center of the tower part 4, the centers of the eight support columns 6, and the center of the buoyancy body part 8 in a straight line, the center of gravity of the floating offshore wind power plant 1 can be positioned at the centers of the tower part 4 and the buoyancy body part 8, and the floating offshore wind power plant 1 can be kept in a balanced horizontal state with respect to the sea surface.

[0031] Fig. 7 shows a partial cross-sectional view of a state where one of the six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16 described in Fig. 5, which is the mooring wire (C) 13, is wound around a wire winding and feeding machine 60 through a mooring wire guide hole (B) 26 of a buoyancy body portion 8. The mooring wire (C) 13 attached to the submarine foundation pile (C) 19 passes through the mooring wire guide hole (B) 26 formed on the side surface of the buoyancy body portion 8 described in Fig. 5, and passes through a wire pulley (B) 62 attached near the mooring wire guide hole (B) 26 on the upper surface of the buoyancy body portion 8, and further passes through a wire pulley (A) 61 attached to the upper surface of the buoyancy body portion 8 near the outside of the vertical hole section 34. Then, it passes through a wire through-hole 63 penetrating the tower base 40 directly above the wire pulley (A) 61, and is attached to a wire winding and feeding machine 60 attached near the outside of the vertical hole section 34 inside the first floor 38 of the building. By winding or feeding out the mooring wire (C) 13 configured in this way by the wire winding and feeding machine 60 to adjust the length, it becomes possible to easily adjust the vertical height of the floating offshore wind power plant 1 with respect to the sea surface 7 and the inclination of the buoyancy body portion 8. By evenly allocating and arranging the wire winding and feeding machines 60 for individually winding and feeding out the six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16 on the circumference near the side surface of the vertical hole section 34 inside the first floor 38 of the building, the space inside the first floor 38 of the building can be utilized efficiently, and it becomes possible to perform maintenance of the wire winding and feeding machine 60 reasonably.

[0032] In Fig. 7, the mooring wire (C) 13 described in Figs. 1 and 2 was explained. However, for the other five mooring wires (A) 11, mooring wire (B) 12, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16, similar to the mooring wire (C) 13, wire pulleys and wire winding / sending machines are utilized, and the lengths of the respective mooring wires are adjusted by the wire pulleys and wire winding / sending machines, so that the horizontal state of the floating offshore wind power plant 1 can be easily maintained.

[0033] As described above, based on the embodiments, the floating offshore wind power plant according to the present invention has been described in detail. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention, and of course, it belongs to the technical scope of the present invention.

[0034] In Figs. 1 and 2, six mooring wires (A) 11, mooring wire (B) 12, mooring wire (C) 13, mooring wire (D) 14, mooring wire (E) 15, and mooring wire (F) 16 were described for mooring the buoyant body 8 to the seabed 9. However, the types of the six mooring wires are not limited to wire ropes, and of course, they can also be composed of synthetic fiber ropes or steel chains.

[0035] In Fig. 1, it was described that the support column 6 was formed of a steel pipe with a diameter of about 2 m, a wall thickness of about 30 mm, and a length of about 10 m. However, of course, it is also possible to form it with a reinforced concrete structure having a cylindrical shape with a diameter of about 2 m, a cylinder thickness of about 20 cm, and a length of about 10 m.

[0036] In Fig. 7, it was explained that "by adjusting the length of the mooring wire (C) 13 configured in this way by the wire winding / sending machine 60, it becomes possible to easily adjust the vertical height and inclination of the floating offshore wind power plant 1 with respect to the sea surface 7." However, of course, it is also possible to adjust the buoyancy of the buoyant body 8 to the planned buoyancy by injecting and discharging ballast water (seawater) into a ballast water tank (not shown) installed inside the buoyant body 8.

Brief Description of the Drawings

[0037]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Explanation of Reference Numerals

[0038] A Upper diameter of the tower part B Upper slab thickness of the tower part C Height of the tower part D Bottom slab thickness of the tower E Height of the support column F Height of the fourth floor of the building G Height of the third floor of the building H Height of the second floor of the building I Height of the first floor of the building J Height of the buoyancy body part K Height of the tip of the front inclined part L Maximum width of the front inclined part M Angle of the front inclined part N Diameter of the buoyancy body part P Angle of the rear inclined part Q Maximum width of the rear inclined part R Height of the rear end of the rear inclined part S Base diameter of the tower part 1 Floating offshore wind power plant 2 Blade 3 nacelle 4 tower part 5 building 6 pillar 7 sea surface 8 buoyancy body part 9 seabed 10 hub 11 mooring wire (A) 12 mooring wire (B) 13 mooring wire (C) 14 mooring wire (D) 15 mooring wire (E) 16 mooring wire (F) 17 seabed foundation pile (A) 18 seabed foundation pile (B) 19 seabed foundation pile (C) 20 seabed foundation pile (D) 21 seabed foundation pile (E) 22 seabed foundation pile (F) 23 steel pipe 24 submarine power transmission cable 25 mooring wire guide hole (A) 26 mooring wire guide hole (B) 27 mooring wire guide hole (C) 28 mooring wire guide hole (D) 29 mooring wire guide hole (E) 30 mooring wire guide hole (F) 31 front inclined part 32 rear inclined part 33 top part 34 vertical hole section 35 4th floor of the building 36 3rd floor of the building 37 2nd floor of the building 38 1st floor of the building 39 tower bottom 40 tower part base 41 dashed line (A) 42 dashed line (B) 43 dashed line (C) 45 pillar (A) 46 pillar (B) 47 pillar (C) 48 Strut (D) 49 Strut (E) 50 Strut (F) 51 Strut (G) 52 Strut (H) 60 Wire winding and feeding machine 61 Pulley (A) for wire 62 Pulley (B) for wire 63 Wire through-hole

Claims

1. In a floating offshore wind power generation system composed of a tower that supports a nacelle incorporating a plurality of blades, a speed increaser, and a generator, a tower section disposed offshore and a buoyancy body section disposed underwater are constructed of reinforced concrete structures, and the tower section and the buoyancy body section are connected by a plurality of columns, and further moored to a plurality of subsea foundation piles fixed to the seabed by a plurality of mooring wires. A floating offshore wind power plant characterized by this.

2. The tower section is generally conical and the lower part is composed of multiple floors of buildings, and the top part is formed with a circular plane, and a steel pipe for attaching a nacelle is attached to the top part. The floating offshore wind power plant according to Claim 1, characterized by this.

3. The buoyancy body section is generally cylindrical and has a hollow interior. In order to float a floating offshore wind power plant constructed on land near the sea on the water, the bottom parts in both the forward and rearward directions are inclined toward the front end part and the rear end part. The floating offshore wind power plant according to Claim 1 or 2, characterized by this.

4. The buoyancy body section is moored in a TLP type by connecting it to a plurality of subsea foundation piles installed on the seabed with a plurality of mooring wires, and one end of the plurality of mooring wires passed through guide holes for mooring wires formed on the side surface of the buoyancy body section is drawn into the building of the tower section via a plurality of wire pulleys, and the individual lengths of the mooring wires are adjusted by a wire winding / feeding machine so as to maintain the horizontal state of the floating offshore wind power plant. The floating offshore wind power plant according to any one of Claims 1 to 3, characterized by this.

5. A vertical hole partition is constructed that penetrates from generally the upper end part of the tower section to generally the lower end part of the buoyancy body section, and a simple lift and a staircase for vertical movement are installed inside the vertical hole partition. The floating offshore wind power plant according to any one of Claims 1 to 4, characterized by this.

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