JP7802265B2 - Floating offshore wind power plant with propulsion unit - Google Patents

Description

The present invention relates to a floating offshore wind power plant that is configured so that a propulsion device is attached to a buoyancy body without mooring the floating offshore wind power plant to the seabed, and the propulsion device is operated using electricity generated by the floating offshore wind power plant, allowing it to propel itself.

In recent years, with the increase in the use of renewable energy, there are no obstacles blocking the wind offshore, and the wind direction and speed are constant and unchanging, so it is expected that a stable supply of electricity can be obtained.
The structure of offshore wind power generation equipment currently in practical use is similar to that of equipment operating on land, and because there are fewer constraints on installation offshore than on land, it is expected that offshore installations will increase in the future.

Currently, the type of offshore wind power generation that is becoming increasingly popular in Europe and other regions, where the support columns reach all the way to the seabed, is suitable for relatively shallow waters of up to about 50 meters. However, in Japan, the area of the continental shelf where the water is relatively shallow is small, so the country is currently transitioning to floating types, in which the wind power generation equipment is floated on the ocean and kept in position by being moored to the seabed with chains, wire ropes, etc.

A floating offshore wind farm consists of a floating body placed underwater and a tower body erected on the floating body. At the top of the tower body is a wind power generation device consisting of a nacelle and blades, and the floating offshore wind farm is maintained in place by being moored to the seabed with chains, wire ropes, etc.
This configuration makes it possible to install a floating offshore wind power plant even in waters with a depth of about 200 m.
Currently, there are four main types of floating offshore wind power technologies in practical use: spar type, semi-submersible type, barge type, and TLP type.

Conventionally, to install floating offshore wind power generation facilities at a designated sea area, the float would be towed to the installation area by a barge or similar vessel and moored there, then moored to the seabed by chains, wire ropes or similar vessels, and the superstructure would be moved to the top of the float by a crane or similar vessel, and the float and superstructure would then be connected.

However, the sea areas with a depth of 50 meters or more where floating offshore wind power plants are installed often have harsher sea conditions than the sea areas where general marine construction work is carried out, and installation work for floating offshore wind power generation equipment must be carried out under harsh sea conditions only when the sea conditions are relatively calm, which creates the problem of limiting the timing and duration of installation work.

Furthermore, the installation of floating offshore wind turbines requires delicate work using large work vessels, which increases construction costs.

Furthermore, the sea areas around Japan that are 50 to 200 meters deep are limited, and as a result, the areas where floating offshore wind power generation equipment can be installed are also limited.

In view of the above current situation, the present invention aims to provide an efficient construction method on land that significantly shortens the number of construction days by constructing facilities for building a floating offshore wind farm on a coast close to the sea, assembling the floating offshore wind farm on land, floating it on the water, and towing it to the sea area where it will be installed using a tugboat or similar. It also aims to provide a floating offshore wind farm that does not require equipment such as chains and wire ropes to moor the floating offshore wind farm to the seabed, sells electricity generated by wind turbines, and uses the generated electricity to operate a propulsion unit, allowing it to remain moored in the same place offshore.

In order to solve this problem, the invention described in claim 1 is a floating offshore wind farm consisting of a tower supporting a nacelle containing multiple blades, a speed increaser, and a generator, in which the tower section placed on the ocean and the buoyant body section placed underwater are constructed of reinforced concrete structures, and the tower section and the buoyant body section are connected by multiple pillars, and a propulsion device is attached to the buoyant body section without mooring the floating offshore wind farm to the seabed, and the propulsion device is operated using electricity generated by the floating offshore wind farm to enable self-propulsion.

The invention described in claim 2 is characterized in that, in addition to the structure described in claim 1, the propulsion device is configured as a 360-degree rotating pod propulsion device.

The invention described in claim 3 is characterized in that, in addition to the structure described in claim 1 or 2, the tower section is generally conical, the lower part is composed of a multi-story building, and the top part is formed as a flat circle.

The invention described in claim 4 is characterized in that, in addition to the structure described in any one of claims 1 to 3, the buoyancy body portion is generally cylindrical and hollow inside, and the bottom in both the forward and rearward directions is inclined toward the front end and rear end in order to float a floating offshore wind power plant constructed on land near the sea on the water.

The invention described in claim 5 is characterized in that, in addition to the structure described in any one of claims 1 to 4, a vertical section is constructed that penetrates from approximately the upper end of the interior of the tower section to approximately the lower end of the buoyancy body section, and a simple lift and a staircase for moving up and down are installed inside.

The invention described in claim 6 is characterized in that, in addition to the structure described in any one of claims 1 to 5, a storage battery facility for storing electricity generated by the floating offshore wind farm is installed in the buoyant body section, and a propulsion device is attached to the buoyant body section to drive a screw propeller, thereby allowing the floating offshore wind farm to remain in the same location on the ocean.

According to the invention of claim 1, in a floating offshore wind farm consisting of a tower supporting a nacelle which has multiple blades and a built-in gearbox and generator, the tower section placed on the ocean and the buoyant body section placed underwater are constructed of a reinforced concrete structure, and the tower section and the buoyant body section are connected by multiple supports, and the floating offshore wind farm is not moored to the seabed, but a propulsion device is attached to the buoyant body section, and the propulsion device is operated using electricity generated by the floating offshore wind farm to enable self-propulsion.This makes it possible to omit chains, wire ropes, etc. used to moor the floating offshore wind farm to the seabed, and makes it possible to install floating offshore wind farms even in sea areas with a water depth of 200m or more.

According to the invention described in claim 2, the propulsion device is configured as a 360-degree rotating pod propulsion device, making it possible to rotate the floating offshore wind power plant of the present invention forward, backward, left and right.

According to the invention described in claim 3, the tower section is roughly conical in shape, with the lower part consisting of a multi-story building and the top part formed as a flat circle, making it possible to construct housing for workers who perform maintenance within the tower section.

According to the invention described in claim 4, the buoyancy body portion is generally cylindrical and hollow inside, and in order to float a floating offshore wind farm constructed on land near the sea on the water, the bottom portions in both the forward and rearward directions are inclined toward the front end and rear end, making it possible to easily float the floating offshore wind farm on the water.

According to the invention described in claim 5, a vertical section is constructed that penetrates from approximately the upper end of the interior of the tower section to approximately the lower end of the buoyancy body section, and a simple lift and stairs for moving up and down are installed inside, making it possible for workers to easily perform maintenance.

According to the invention described in claim 6, by installing a power storage facility in the buoyancy body section to store the electricity generated by the floating offshore wind farm, and by attaching a propulsion device to the buoyancy body section to drive a screw propeller, it is now possible to moor the floating offshore wind farm in the same location offshore with a simple structure.

A first embodiment of the present invention will now be described.
[First embodiment of the invention]

1 to 6 show a first embodiment of the present invention.

1 is a perspective view showing a propulsion-equipped floating offshore wind farm 1 of the present invention installed offshore. The propulsion-equipped floating offshore wind farm 1 comprises three blades 2 attached to a hub 10, a gearbox, generator, yaw control device, etc. installed inside a nacelle 3, a steel pipe 11 for attaching the nacelle 3 to a tower section 4, the tower section 4 constructed of a reinforced concrete structure, eight support columns 6 made of steel pipes with a diameter of approximately 2 m, a thickness of approximately 30 mm, and a length of approximately 10 m for connecting the tower section 4 and a buoyancy body section 8, and a reinforced concrete structure with a hollow interior for allowing the propulsion-equipped floating offshore wind farm 1 to float independently on the ocean and function as a floating structure. The floating offshore wind farm 1 with the propulsion unit is constructed of a buoyancy body 8, and a plurality of ballast water tanks (not shown) are installed inside the buoyancy body 8 so that the floating offshore wind farm with the propulsion unit 1 can be kept horizontal with respect to the sea surface 7 while preventing it from tipping over. By injecting or discharging seawater into the ballast water tanks, the buoyancy of the buoyancy body 8 can be adjusted so that the position of the sea surface 7 is approximately centered vertically between the columns 6, and the inclination of the floating offshore wind farm with the propulsion unit 1 with respect to the sea surface 7 can be controlled by injecting or discharging seawater into the plurality of ballast water tanks so that the horizontal state can be maintained with respect to the sea surface 7. Electricity generated by the generator inside the nacelle 3 constructed in this manner is sent via an undersea power transmission cable 14 to an onshore switchgear and connected to the existing power transmission line. In order to operate the propulsion unit 12 described in Figure 2 in a stable state, the electricity generated by the generator is also stored in a storage battery facility 16 installed inside the buoyancy body 8, allowing the propulsion unit 12 to operate in a stable state. In addition, in order to improve power generation efficiency, a yaw drive device (not shown) is installed inside the nacelle 3 so that the blades 2 can be rotated freely 360 degrees relative to the steel pipe 23, and the orientation of the blades 2 is controlled so that they always face the wind direction.

Figure 2 is a front view of the floating offshore wind farm 1 with propulsion units described in Figure 1. In the present invention, in order to ensure a constant stable supply of power to the propulsion units 12, 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 8, and the electricity is then used to drive the propulsion units 12. This allows the floating offshore wind farm 1 with propulsion units to remain in the same location offshore by utilizing the power from the power storage facility 16 even in windless conditions where the blades 2 do not rotate and the generator does not generate power. The propulsion device 12 in the present invention is configured so that two 360-degree rotating pod propulsion devices 15, which can generate thrust almost evenly in all directions over 360 degrees, are attached side by side at approximately the center of the lower part of the buoyancy body section 8, and by operating and driving the rotation speed and rotation angle of the two 360-degree rotating pod propulsion devices 15 separately, the floating offshore wind farm 1 with propulsion devices can be turned in the forward/backward and left/right directions, and the floating offshore wind farm 1 with propulsion devices can be moored in the same location offshore.

Figure 3 shows the tower section 4, support column 6, buoyancy body section 8, and propulsion device 12 described in Figures 1 and 2 in a plan view in Figure 3a and a front view in Figure 3b. The tower section 4 is constructed of a roughly conical reinforced concrete structure, and as shown in Figure 5, the diameter A of the upper part of the tower section is formed in a circular shape with a diameter of about 5 m, the thickness B of the upper tower section slab is about 500 mm, the height C of the tower section from the top 33 of the tower section 4 to the tower bottom 39 is about 97 m, the thickness D of the tower bottom slab constituting the tower section base 40 of the tower section 4 is about 1 m, the diameter T of the tower base constituting the tower section base 40 is formed in a circular shape with a diameter of about 25 m, and below the tower section 4 is constructed a four-story building 5 (shown as a first floor building 38, a second floor building 37, a third floor building 36, and a fourth floor building 35) with each floor being about 5 m high. The buoyancy unit 8 is formed in a roughly cylindrical shape, and is hollow inside to serve as a float that floats the floating offshore wind farm 1 with a propulsion unit on the ocean, and is constructed so that the center of the buoyancy unit 8 and the center of the tower unit 4 are aligned in a straight line. Furthermore, as shown in Figure 5, the buoyancy unit 8 is formed in a roughly cylindrical shape, and the diameter N of the buoyancy unit is about 100 m, and the height J of the buoyancy unit 8 excluding the forward inclined portion 31 and the rear inclined portion 32 is about 10 m. Furthermore, as shown in Figure 3, in front of and behind the bottom of the buoyancy unit 8, in order to float the floating offshore wind farm 1 with a propulsion unit constructed on land on the water in a stable state, the bottom in both the forward and rearward directions is formed by the forward inclined portion 31 (the boundary between the bottom and the forward inclined portion 31 is indicated by the dashed dotted line (A) in Figure 3a). 3a) toward the front and rear ends as shown by the forward inclined portion angle M and the rear inclined portion angle P in Figure 5, and further, eight supports 6 made of steel pipes with a diameter of approximately 2 m, a thickness of approximately 30 mm, and a length of approximately 10 m are attached at equal distances from the center of the top surface of the buoyancy body section 8 to connect the tower section 4 and the buoyancy body section 8. As explained in Figure 1, multiple ballast water tanks (not shown) are installed inside the buoyancy body section 8, and 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 in the center of the vertical direction of the support 6, and the inclination of the floating offshore wind power plant 1 with propulsion devices relative to the sea surface 7 can be maintained horizontally by injecting or discharging seawater into the multiple ballast water tanks.

Furthermore, a cylindrical pit section 34 with a diameter of approximately 4 m was constructed as shown by the dotted line (C) 41, extending from approximately the top 33 of the tower section 4 through the tower bottom 39 to approximately the bottom of the center of the buoyancy body section 8, and a staircase (not shown) for moving up and down and a simple lift (not shown) for carrying out inspection work were installed inside the pit section 34, making it possible for workers to carry out inspections efficiently.

Figure 4 shows the support columns 6 and buoyancy body section 8 described in Figures 1 and 2 in a plan view in Figure 4a and a front view in Figure 4b. The eight support columns 6 are all formed from cylindrical steel pipes with a diameter of approximately 2 m, a thickness of 30 mm, and a length of 10 m. As shown in the plan view in Figure 4a, eight support columns (A) 45, (B) 46, (C) 47, (D) 48, (E) 49, (F) 50, (G) 51, (H) 52, and (H) 53 are arranged radially at 45-degree intervals when viewed in a horizontal plane on a circumference with a radius of approximately 1050 cm from the center of the top surface of the buoyancy body section 6. The eight columns (A) 45, (B) 46, (C) 47, (D) 48, (E) 49, (F) 50, (G) 51, and (H) 52 are attached to the tower base 40 at positions where the tops of the eight columns (A) 45, (B) 46, (C) 47, (D) 48, (E) 49, (F) 50, (G) 51, and (H) 52 are attached to the underside of the tower base 40 so that the center of the underside of the tower bottom 39 described in Figure 3 and the center of the buoyancy body 8 are aligned in a straight line. The reason for connecting the tower 4 and the buoyancy body 8 with eight columns (6) in this way is that by supporting the tower 4 with cylindrical, round columns with a diameter of approximately 2 m, resistance from wind and waves on the sea surface can be minimized, the swaying of the propulsion-equipped floating offshore wind farm 1 can be suppressed, and the blades can be faced against the wind.

5 shows the dimensions and angles of the tower section 4, columns 6, and buoyancy body section 8 components described in Figures 1 and 2 using symbols A to T. The tower section 4 is generally conical, with a top section 33 formed by a circular plane, the diameter A of the tower section upper part of the top section 33 is formed as a circle with a diameter of about 5 m, and the thickness B of the tower section upper part of the top section 33 is formed as a circle with a diameter of about 500 mm, and further, as shown by the dashed dotted line (C) 41, the pit section 34 penetrates the tower section base 40 from approximately the upper end of the tower section 33 to approximately the lower end of the buoyancy body section 8, and is formed as a cylinder with a diameter of about 4 m and an internal height of about 116.3 m. Furthermore, the tower height C from the top 33 of the tower section 4 to the tower bottom 39 is approximately 97 m, and the four-story building 5 has a fourth-floor height F of approximately 5 m, a third-floor height G of approximately 5 m, a second-floor height H of approximately 5 m, and a first-floor height I of approximately 5 m. The tower bottom slab thickness D at the bottom of the tower section 4 is approximately 1 m, and the tower base diameter T at the bottom of the tower section 4 is cylindrical and has a diameter of approximately 25 m. Furthermore, the height E of all eight support columns 6 is approximately 10 m. Furthermore, the buoyancy body section 8, which is constructed with a reinforced concrete structure and a hollow interior, has a reinforced concrete thickness of approximately 200 mm at the top, bottom, and outer periphery. Furthermore, a hole with a diameter of approximately 4 m is formed in the center of the top of the buoyancy body section 8 to allow the vertical section 34 to pass through. Furthermore, the front and rear bottoms of the buoyant body section 8 are formed in a shape that is inclined in the forward and rearward directions, and the buoyant body section diameter N of the buoyant body section 8 is formed in a cylindrical shape with a diameter of approximately 100 m, and the buoyant body section height J excluding the forward inclined section 31 and the rear inclined section 32 of the buoyant body section 8 described in Figure 3 is formed to be approximately 10 m, and the forward inclined section tip height K and the rear inclined section rear end height R of the tip of both the forward inclined section 31 and the rear inclined section 32 in the forward and rearward directions of the buoyant body section 8 described in Figure 3 are both formed to be approximately 3 m, and the forward inclined section angle M and the rear inclined section angle P of the forward inclined section 31 and the rear inclined section 32 described in Figure 3 are both formed to be approximately 14 degrees, and the forward inclined section maximum width L of the forward inclined section 31 described in Figure 3 and, similarly, the rear inclined section maximum width Q of the rear inclined section 32 are both formed to be approximately 12 m.

A second embodiment of the present invention will now be described.
Second Embodiment

Figure 6 shows a second embodiment of the present invention. In the first embodiment of the present invention, as shown in Figure 3a, two propulsion units 12 are mounted side by side at approximately the center of the lower part of the buoyancy body unit 8. In contrast, in the second embodiment of the present invention, two propulsion units 69 (specifically, 360-degree swivel pod propulsion units 70) are arranged in parallel and mounted approximately at the rear end of the buoyancy body unit 66. By changing and controlling the rotation speed and swivel angle of the two propulsion units 69, the floating offshore wind farm with propulsion units of the present invention can be moored in the same location offshore. The remaining structure is the same as that of the first embodiment of the present invention.

The above has described in detail the floating offshore wind farm with propulsion devices according to the present invention based on the embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention without departing from the spirit of the invention, and of course, still fall within the technical scope of the present invention.

In FIG. 1, it has been explained that the support pillar 6 is formed from a steel pipe having a diameter of about 2 m, a thickness of about 30 mm, and a length of about 10 m. However, it is of course also possible to form the support pillar 6 from a cylindrical reinforced concrete structure having a diameter of about 2 m, a thickness of about 20 cm, and a length of about 10 m.

1 is a perspective view showing a floating offshore wind farm with a propulsion device according to a first embodiment of the present invention. 2 is a front view of the floating offshore wind power plant with propulsion devices shown in FIG. 1 according to the embodiment. 2A and 2B are plan and front views of a tower section, a support column, a buoyancy body section, and a propulsion device according to the embodiment. 2A and 2B are plan and front views of a support column, a buoyancy body, and a propulsion device according to the embodiment. FIG. 2 is a front view of the tower section, the support column, the buoyancy body section, and the propulsion device according to the embodiment. FIG. 10 is a front view showing a state in which a propulsion device is attached to the rear end of a buoyant body according to a second embodiment of the present invention.

A Diameter of top of tower B Thickness of top slab of tower C Height of tower D Thickness of bottom slab of tower E Height of support pillar F Height of fourth floor of building G Height of third floor of building H Height of second floor of building I Height of first floor of building J Height of buoyancy body K Height of tip of forward inclined part L Maximum width of forward inclined part M Angle of forward inclined part N Diameter of buoyancy body P Angle of rear inclined part Q Maximum width of rear inclined part R Height of rear end of rear inclined part 1 Floating offshore wind power plant with propulsion unit 2 Blade 3 Nacelle 4 Tower 5 Building 6 Support pillar 7 Sea surface 8 Buoyancy body 9 Seabed 10 Hub 11 Steel pipe 12 Propulsion unit 13 Screw propeller 14 Submarine power transmission cable 15 360-degree rotating pod propulsion unit 16 Battery equipment 29 Dash-dotted line (A)
30 One-dot chain line (B)
31 Forward inclined portion 32 Rear inclined portion 33 Top portion 34 Pit section 35 Building 4th floor 36 Building 3rd floor 37 Building 2nd floor 38 Building 1st floor 39 Tower bottom 40 Tower base 41 Dash line (C)
45 Support (A)
46 Pillar (B)
47 Pillar (C)
48 Pillar (D)
49 Pillar (E)
50 Pillar (F)
51 Pillar (G)
52 Pillar (H)
60 Tower section 61 Top section 62 One-dot chain line 63 Pit section 64 Building 65 Support 66 Buoyancy body section 67 Screw propeller 68 Rudder 69 Propulsion device 70 360-degree rotating pod propulsion device

Claims (6)

In floating offshore wind power plants, which consist of a tower supporting multiple blades and a nacelle containing a gearbox and generator,
A tower section placed on the ocean and a buoyant body section placed underwater are constructed with a reinforced concrete structure, and the tower section and the buoyant body section are connected with a plurality of supports,
A floating offshore wind power plant with a propulsion device is configured so that the floating offshore wind power plant is not moored to the seabed, but a propulsion device is attached to the buoyancy body, and the propulsion device is operated using electricity generated by the floating offshore wind power plant, allowing it to propel itself. 2. The floating offshore wind power plant with a propulsion device according to claim 1, wherein the propulsion device is a 360-degree rotating 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, with the lower section being composed of a multi-story building and the top section being formed in a flat circular shape. 4. A floating offshore wind farm with a propulsion device according to any one of claims 1 to 3, characterized in that the buoyancy body is generally cylindrical with a hollow interior, and the bottoms in both the forward and rearward directions are inclined toward the front end and rear end in order to float the floating offshore wind farm constructed on land near the sea on the water. A floating offshore wind power plant with a propulsion device as described in any one of claims 1 to 4, characterized in that a vertical compartment is constructed that penetrates from approximately the upper end of the interior of the tower section to approximately the lower end of the buoyancy body section, and a simple lift and a staircase for vertical movement are installed inside. 6. A floating offshore wind farm with a propulsion device according to any one of claims 1 to 5, characterized in that a storage battery facility for storing electricity generated by the floating offshore wind farm is installed in the buoyancy body section, and a propulsion device is attached to the buoyancy body section to drive a screw propeller, thereby allowing the floating offshore wind farm to remain in the same place on the ocean.