Floating offshore wind farm with propulsion device

Abstract

To provide a floating offshore wind farm which can omit a chain or a wire rope etc. for mooring a floating offshore wind power facility to the seabed and operate a propulsion device attached to a buoyancy body part with electricity generated by a wind power generator to be retained at the same position on the ocean.SOLUTION: In a floating offshore wind farm with a propulsion device, a tower part disposed on the ocean and a buoyancy body part disposed in water are built by reinforced-concrete structures, and the tower part and the buoyancy body part are connected by a plurality of pillars. Further, a floating offshore wind power facility is not moored to the seabed, and a propulsion device is attached to the buoyancy body part to operate the propulsion device with electricity generated by the floating offshore wind power facility and thereby allow the floating offshore wind farm to be self-propelled. The floating offshore wind farm with the propulsion device is provided so as to achieve the above object.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a floating offshore power plant configured such that a propulsion device is attached to a buoyancy body part without mooring a floating offshore wind power facility to the seabed, and the propulsion device can be operated with electricity generated by the floating offshore wind power facility to achieve self-navigation.

Background Art

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

[0003] Currently, in the case of the bottom-fixed offshore wind power generation where the support reaches the seabed and is spreading in Europe and other places, 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 mooring to the seabed with a chain, wire rope, etc.

[0004] A floating offshore power plant is composed of a floating body part arranged in water and a tower part erected on the floating body, and includes a wind power generation device composed of a nacelle and blades at the top of the tower part, and maintains the position of the floating offshore power plant by mooring to the seabed with a chain, wire rope, etc. By configuring in this way, it is possible to install a floating offshore power plant even in a sea area with a water depth of about 200 m. Currently, the floating offshore wind power technologies that have been put into practical use mainly include four types: spar type, semi-submersible type, barge type, and TLP type.

[0005] Conventionally, in order to install a floating type offshore wind power generation facility at a specified sea area location, after towing and mooring the floating body to the installation sea area by a mother ship or the like, it was moored to the seabed by a chain, a wire rope, etc., and the upper structure was moved to the upper end of the floating body by a crane ship or the like, and the floating body and the upper structure were connected.

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in sea areas with a water depth of 50 m or more where floating type offshore wind power plants are installed, the sea state conditions are often more severe compared to sea areas where general ocean engineering is carried out. The installation work of the floating type offshore wind power generation device must be carried out taking into account a relatively calm sea state period under severe sea state conditions. Therefore, there was a problem that the implementation time and period of the installation work were limited.

[0007] Furthermore, the installation of the floating type offshore wind power generation device requires delicate work using large work ships, so there was also a problem of increasing the construction cost.

[0008] Furthermore, in the coastal waters of Japan, the sea areas with a water depth of about 50 m to 200 m are narrow and limited. Therefore, the sea areas where the floating type offshore wind power generation device can be installed are also limited.

[0009] In view of the above situation, an object of the present invention is to construct a facility for constructing a floating type offshore wind power plant near the sea coast, float the floating type offshore wind power plant assembled on land on the water, and tow it to the installation sea area by a tugboat (towboat) or the like, thereby significantly shortening the construction days and providing an efficient construction method on land. Another object is to eliminate the need for facilities such as chains and wire ropes for mooring the floating type offshore wind power plant to the seabed, sell the electricity generated by the wind power generation device, operate the propulsion device with the generated electricity, and provide a floating type offshore wind power plant capable of staying at the same location on the ocean.

Means for Solving the Problems

[0010] In order to solve such problems, the invention according to claim 1 is a floating offshore wind power plant composed of a tower that supports a nacelle incorporating a plurality of blades, a speed increaser, and a generator, wherein the tower part arranged on the sea 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, and a propulsion device is attached to the buoyancy body part without mooring the floating offshore wind power plant to the seabed, and the propulsion device is operated with the electricity generated by the floating offshore wind power plant to make it self-propelled.

[0011] The invention according to claim 2 is characterized in that, in addition to the structure according to claim 1, the propulsion device is composed of a 360-degree swivel pod propulsion device.

[0012] The invention according to claim 3 is characterized in that, in addition to the structure according to claim 1 or 2, the tower part is generally conical, the lower part is composed of a multi-story building, and the top part is formed in a planar circular shape.

[0013] The invention according to claim 4 is characterized in that, in addition to the structure according to any one of claims 1 to 3, the buoyancy body part is generally cylindrical and has a hollow inside, and 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.

[0014] The invention according to claim 5 is characterized in that, in addition to the structure according to any one of claims 1 to 4, a vertical hole partition penetrating from generally the upper end part inside 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.

[0015] The invention according to claim 6 is characterized in that, in addition to the structure according to any one of claims 1 to 5, a power storage facility for storing the electricity generated by the floating offshore wind power plant is installed in the buoyancy body part, and by attaching a propulsion device to the buoyancy body part and driving a screw propeller, the floating offshore wind power plant is configured to stay at the same location on the sea.

Effect of the Invention

[0016] According to the invention described in claim 1, in a floating offshore wind power plant composed of a tower that supports a plurality of blades and a nacelle incorporating a speed increaser and a generator, the tower section arranged on the sea and the buoyancy body section arranged underwater are constructed with a reinforced concrete structure, and the tower section and the buoyancy body section are connected by a plurality of columns. Without mooring the floating offshore wind power plant to the seabed, a propulsion device is attached to the buoyancy body section, and the propulsion device is operated with the electricity generated by the floating offshore wind power plant to achieve self-navigation. As a result, it becomes possible to omit chains, wire ropes, etc. for mooring the floating offshore wind power plant to the seabed, and it becomes possible to install a floating offshore wind power plant even in a sea area with a water depth of 200 m or more.

[0017] According to the invention described in claim 2, since the propulsion device is composed of a 360-degree swivel pod propulsion device, it becomes possible to turn the floating offshore wind power plant of the present invention in all directions.

[0018] According to the invention described in claim 3, since the tower section is generally conical and the lower part is composed of multiple floors of buildings and the top part is formed in a planar circle, it becomes possible to construct a living quarters for workers for maintenance inside the tower section.

[0019] According to the invention described in claim 4, since the buoyancy body section is generally cylindrical and has a hollow inside, and 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 and the rear end, it becomes possible to easily float the floating offshore wind power plant on the water.

[0020] According to the invention described in claim 5, a vertical hole partition penetrating from generally the upper end inside the tower section to generally the lower end of the buoyancy body section is constructed, and a simple lift and stairs for vertical movement are installed inside, making it possible for workers to easily perform maintenance.

[0021] According to the invention described in claim 6, an energy storage facility for storing the electricity generated by the floating offshore wind power plant is installed in the buoyancy body part, and a propulsion device is attached to the buoyancy body part to drive a screw propeller, so that the floating offshore wind power plant can be kept stationary at the same location offshore with a simple structure.

Example 1

[0022] Hereinafter, Embodiment 1 of this invention will be described. [Embodiment 1 of the Invention]

[0023] Figs. 1 to 6 show Embodiment 1 of this invention.

[0024] FIG. 1 shows a perspective view of a floating offshore wind power plant 1 with a propulsion device installed offshore. The floating offshore wind power plant 1 with a propulsion device includes three blades 2 attached to a hub 10, a speed increaser, a generator, a yaw control device, etc. installed inside a nacelle 3, a steel pipe 11 for attaching the nacelle 3 to a tower section 4, a tower section 4 constructed with a reinforced concrete structure, eight struts 6 formed of steel pipes with a diameter of about 2 m, a thickness of about 30 mm, and a length of about 10 m for connecting the tower section 4 and a buoyancy body section 8, and a buoyancy body section 8 formed with a reinforced concrete structure with a hollow interior to float the floating offshore wind power plant 1 with a propulsion device offshore and make it self-supporting, serving as a floating structure section. Further, inside the buoyancy body section 8, a plurality of ballast water tanks (not shown) are installed so that the floating offshore wind power plant 1 with a propulsion device maintains a horizontal state with respect to the sea surface 7 and does not roll over at the same time. By injecting or discharging seawater into the ballast water tanks, the buoyancy of the buoyancy body section 8 is adjusted so that the position of the sea surface 7 is approximately at the vertical center of the struts 6, and the inclination of the floating offshore wind power plant 1 with a propulsion device with respect to the sea surface 7 can also be maintained in a horizontal state with respect to the sea surface 7 by injecting or draining seawater into the plurality of ballast water tanks. The electricity generated by the generator inside the nacelle 3 configured as described above is sent to an onshore switchyard via a submarine power transmission cable 14 and connected to an existing system power transmission line. At the same time, in order to operate the propulsion device 12 described in FIG. 2 in a stable state, the electricity generated by the generator is also stored in a battery facility 16 installed inside the buoyancy body section 8 to operate the propulsion device 12 in a stable state. In addition, inside the nacelle 3, in order to improve the power generation efficiency, a yaw drive device (not shown) is attached so that the blade 2 can be rotated 360 degrees freely with respect to the steel pipe 23 to perform azimuth control so that the blade 2 always faces directly into the wind direction.

[0025] FIG. 2 shows a front view of the floating offshore wind power plant 1 with a propulsion device described in FIG. 1. In the present invention, in order to always supply stable power to the propulsion device 12, the electricity generated by a generator (not shown) inside the nacelle 3 is stored in a power storage facility 16 (not shown) installed inside the buoyancy body portion 8, and then the propulsion device 12 is driven by the electricity, so that even in a state where the blade 2 does not rotate and the generator does not generate electricity in a windless state, the floating offshore wind power plant 1 with a propulsion device can be kept at the same location on the sea by utilizing the power of the power storage facility 16. The propulsion device 12 in the present invention is configured by attaching two 360-degree swivel pod propulsion devices 15 that can generate thrust almost evenly in all 360-degree directions side by side at approximately the center lower part of the buoyancy body portion 8, and by operating and driving the rotation speeds and swivel angles of the two 360-degree swivel pod propulsion devices 15 separately, the floating offshore wind power plant 1 with a propulsion device can be turned in the front-rear, left-right directions so that the floating offshore wind power plant 1 with a propulsion device can be stopped at the same location on the sea.

[0026] Figure 3 shows the tower section 4, the support column 6, the buoyancy body section 8, and the propulsion device 12 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 reinforced concrete structure generally in a conical shape. As shown in FIG. 5, the upper diameter A of the tower section is formed into a circular shape with a diameter of about 5 m, the upper slab thickness B of the tower section is about 500 mm, the tower height C of the tower section 4 from the top 33 of the tower section to the bottom 39 of the tower is about 97 m, the bottom slab thickness D of the tower base 40 constituting the tower section 4 of the tower section is about 1 m, the tower base diameter T of the tower base 40 constituting the tower base is formed in a circular shape with a diameter of about 25 m. At the lower part of the tower section 4, 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) with each floor height formed to be about 5 m is constructed. The buoyancy body section 8 is generally formed in a cylindrical shape and serves as a floating body for floating the floating type offshore wind power generation plant 1 with a propulsion device on the sea, so the inside is formed as a cavity and is constructed so that the center of the buoyancy body section 8 and the center of the tower section 4 are on a straight line. Further, as shown in FIG. 5, the buoyancy body section 8 is generally formed in a cylindrical shape, the buoyancy body diameter N is about 100 m, and the buoyancy body height J excluding the front inclined portion 31 and the rear inclined portion 32 of the buoyancy body section 8 is formed to be about 10 m. Further, as shown in FIG. 3, in order to float the floating type offshore wind power generation plant 1 with a propulsion device constructed on land stably on the water in the front and rear of the bottom surface of the buoyancy body section 8, the bottom surfaces in both the front and rear directions are inclined at an angle of about 14 degrees as shown by the front inclined portion 31 (the boundary between the bottom surface and the front inclined portion 31 is shown by a dashed-dotted line (A) 29 in FIG. 3a) and the rear inclined portion 32 (the boundary between the bottom surface and the rear inclined portion 32 is shown by a dashed-dotted line (B) 30 in FIG. 3a) toward the front end and the rear end, as shown by the front inclined portion angle M and the rear inclined portion angle P in FIG. 5. Further, in order to connect the tower section 4 and the buoyancy body section 8, a state is shown in which eight support columns 6 made of steel pipes with a diameter of about 2 m, a wall thickness of about 30 mm, and a length of about 10 m are attached at equal distances from the center of the upper surface of the buoyancy body section 8.As described with reference to FIG. 1, a plurality of ballast water tanks (not shown) are installed inside the buoyancy body 8. By injecting or discharging seawater into / from the ballast water tanks, the buoyancy of the buoyancy body 8 is adjusted so that the position of the sea surface 7 is approximately at the vertical center of the support column 6. At the same time, the inclination of the floating body type offshore wind power plant 1 with a propulsion device with respect to the sea surface 7 is also configured to maintain a horizontal state by injecting or draining seawater into / from the plurality of ballast water tanks.

[0027] Furthermore, a vertical hole section 34 is constructed that penetrates from approximately the top part 33 to the tower bottom 39 of the tower section 4 and is formed in a cylindrical shape with an approximate diameter of 4 m as shown by the dashed line (C) 41 to approximately the bottom part at the center of the buoyancy body 8. Further, by installing a staircase for vertical movement (not shown) and a simple lift (not shown) for inspection work inside the vertical hole section 34, workers can efficiently perform inspections.

[0028] FIG. 4 shows the support column 6 and the buoyancy body 8 described in FIGS. 1 and 2 in a plan view of FIG. 4a and a front view of FIG. 4b. All eight support columns 6 are formed of cylindrical steel pipes with an approximate diameter of 2 m, a wall thickness of 30 mm, and a length of 10 m. As shown in the plan view of FIG. 4a, they are vertically attached so that the centers of the eight support columns (A) 45, support column (B) 46, support column (C) 47, support column (D) 48, support column (E) 49, support column (F) 50, support column (G) 51, and support column (H) 52 are located at positions radially extending at 45-degree intervals on a circumference with a radius of approximately 1050 cm from the center of the upper surface of the buoyancy body 6 when viewed horizontally. The attachment positions of the upper parts of the eight support columns (A) 45, support column (B) 46, support column (C) 47, support column (D) 48, support column (E) 49, support column (F) 50, support column (G) 51, and support column (H) 52 to the tower section base 40 are attached to the lower surface of the tower section base 40 where the center of the lower surface of the tower bottom 39 described in FIG. 3 and the center of the buoyancy body 8 are aligned in a straight line. The reason for connecting the tower section 4 and the buoyancy body 8 with the eight support columns 6 is to minimize the resistance due to the wind and waves on the sea surface by supporting the tower section 4 with cylindrical support columns with an approximate round diameter of 2 m, suppress the sway of the floating body type offshore wind power plant 1 with a propulsion device, and make the blades face the wind.

[0029] Figure 5 shows the dimensions and angles of the members of the tower part 4, the support column 6, and the buoyancy body part 8 described in FIGS. 1 and 2, indicated by symbols A to T. The tower part 4 is generally conical, and the top part 33 is formed as a circular plane. The upper diameter A of the tower part at the top part 33 is formed as a circle with a diameter of about 5 m. Further, the upper slab thickness B of the tower part at the top part 33 is formed to be about 500 mm. Further, as shown by the dashed-dotted line (C) 41, the vertical hole section 34 penetrates from approximately the upper end of the tower part 33 through the tower base 40 to approximately the lower end of the buoyancy body part 8 and is formed as a cylindrical shape with an internal diameter of about 4 m and a height of about 116.3 m. Further, the tower height C of the tower part 4 from the top part 33 to the tower bottom 39 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 tower bottom slab thickness D at the bottom of the tower part 4 is formed to be about 1 m, and the tower base diameter T at the lower part of the tower part 4 is formed as a cylindrical shape with a diameter of about 25 m. Further, the heights E of all eight support columns 6 are all formed to be about 10 m. Further, the thickness of the reinforced concrete of the buoyancy body part 8 constructed with a hollow inside by a reinforced concrete structure is all formed to be about 200 mm for the upper part, the lower part, and the outer peripheral surface. Further, a hole with a diameter of about 4 m is formed at the center of the upper part of the buoyancy body part 8 to penetrate the vertical hole section 34. Further, the front and rear bottoms of the buoyancy body part 8 are formed in a shape inclined forward and backward. Further, the buoyancy body diameter N of the buoyancy body part 8 is formed as a cylindrical shape with a diameter of about 100 m. Further, the buoyancy body height J 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 front inclined part tip height K at the tip of both the front inclined part 31 and the rear inclined part 32 in the front and rear directions of the buoyancy body part 8 described in FIG. 3, and the rear inclined part rear end height R 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. The front inclined part maximum width L of the front inclined part 31 described in FIG. 3 and, similarly, the rear inclined part maximum width Q of the rear inclined part 32 are both formed to be about 12 m.

Embodiment 2

[0030] Hereinafter, Embodiment 2 of the present invention will be described. [Embodiment 2 of the Invention]

[0031] Figure 6 shows Embodiment 2 of the present invention. In Embodiment 1 of the above invention, as shown in FIG. 3a, two propulsion devices 12 were mounted side by side at approximately the center lower part of the buoyancy body 8, whereas in Embodiment 2 of the present invention, two propulsion devices 69 (specifically, 360-degree swiveling pod propulsion devices 70) are arranged in parallel and mounted at approximately the rear end of the buoyancy body 66, and by controlling by changing the rotation speed and swivel angle of the two propulsion devices 69 respectively, the floating type offshore wind power generation plant with a propulsion device of the present invention is configured to be able to stay at the same location offshore. Regarding other structures, they are the same as those in Embodiment 1 of the present invention.

[0032] As described above, based on the embodiments, the floating type offshore wind power generation plant with a propulsion device 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.

[0033] 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, it is of course possible to form the support column 6 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.

Brief Description of the Drawings

[0034]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Explanation of reference numerals

[0035] A Upper diameter of the tower part B Thickness of the upper slab of the tower part C Height of the tower part D Thickness of the bottom slab of the tower E Height of the support column F Height of the 4th floor of the building G Height of the 3rd floor of the building H Height of the 2nd floor of the building I Height of the 1st 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 1 Floating type offshore wind power plant with a propulsion device 2 Blade 3 Nacelle 4 Tower part 5 Building 6 Support column 7 Sea surface 8 Buoyancy body part 9 Seabed 10 Hub 11 Steel pipe 12 Propulsion device 13 Screw propeller 14 Submarine power transmission cable 15 360-degree swivel pod propulsion device 16 Battery equipment 29 Dashed line (A) 30 Dashed line (B) 31 Front inclined part 32 Rear inclined part 33 Top part 34 Vertical hole section 35 4th floor of the building 3-story building 3 2-story building 37 1-story building 38 Bottom of tower 39 Tower base 40 Dash-dotted line (C) 41 Column (A) 45 Column (B) 46 Column (C) 47 Column (D) 48 Column (E) 49 Column (F) 50 Column (G) 51 Column (H) 52 Tower section 60 Top section 61 Dash-dotted line 62 Vertical hole section 63 Building 64 Column 65 Buoyancy body section 66 Screw propeller 67 Rudder 68 Propulsion device 69 360-degree swivel pod propulsion device 70

Claims

1. In a floating offshore wind power plant 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 a reinforced concrete structure, and the tower section and the buoyancy body section are connected by a plurality of columns, A floating offshore wind power plant with a propulsion device, characterized in that a propulsion device is attached to the buoyancy body section without mooring the floating offshore wind power plant to the seabed, and the propulsion device is operated by the electricity generated by the floating offshore wind power plant to achieve self-navigation.

2. The floating offshore wind power plant with a propulsion device according to Claim 1, characterized in that the propulsion device is composed of a 360-degree swiveling pod propulsion device.

3. The floating offshore wind power plant with a propulsion device according to Claim 1 or 2, characterized in that the tower section is generally conical, the lower part is composed of a multi-story building, and the top part is formed in a flat circular shape.

4. The floating offshore wind power plant with a propulsion device according to any one of Claims 1 to 3, characterized in that the buoyancy body section is generally cylindrical with a hollow interior, and 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 and the rear end.

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

6. The floating offshore wind power plant with a propulsion device according to any one of Claims 1 to 5, characterized in that a power storage facility for storing the electricity generated by the floating offshore wind power plant is installed in the buoyancy body section, and the floating offshore wind power plant is configured to stay in the same location offshore by attaching a propulsion device to the buoyancy body section and driving a screw propeller.

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