JP2021075864A - Wind power generator caisson and floating method for the same - Google Patents

Abstract

To provide a wind power generator caisson capable of ensuring movement of a caisson skeleton and easy floating of the caisson skeleton during removal.SOLUTION: This wind power generator caisson comprises: a caisson skeleton 4 installed in a water bottom as a base for a wind power generator 1; discharge means 15 for discharging water from the caisson skeleton 4; and injection means 19 for injecting water or air from the caisson skeleton 4 toward the water bottom.SELECTED DRAWING: Figure 1

Description

The present invention relates to a caisson for a wind power generation device that is sunk on the bottom of the water as the basis of the wind power generation device and a method for ascending the caisson.

Generally, for example, a pile foundation or the like is used as the foundation of an offshore wind power generation device. This pile foundation is planned and installed so that it can be pulled out or cut in water when it is removed.

Further, as the foundation of the offshore wind power generation device, there is also one using a caisson as described in Patent Document 1. In the foundation using this caisson, a friction increasing mat is provided on the bottom surface of the caisson to increase the frictional resistance, and a high specific density material such as metal slag or ore is used as the filling material to increase the sliding resistance of the caisson. ..

Japanese Unexamined Patent Publication No. 2006-322400

As mentioned above, when a pile foundation is used as the foundation of an offshore wind turbine, it may be difficult to pull out all the pile foundations reliably due to work, and a large marine facility is required to pull out. Therefore, there is a problem that the work cost is high. Further, when the pile foundation is cut underwater, there is a problem in terms of safety of the cutting work.

Further, in the case of using the caisson described in Patent Document 1, when the caisson is floated at the time of moving or withdrawing the caisson, it is necessary to discharge the filling material of the high specific density material from the inside of the caisson, so that the work efficiency is improved. There is a problem that it is extremely bad.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a caisson for a wind power generator and a method for floating the caisson skeleton, which can reliably and easily levitate the caisson skeleton when moving or withdrawing the caisson skeleton. And.

In order to solve the above problems, the invention according to claim 1 of the present invention includes a caisson skeleton that is sunk on the bottom of the water as the basis of a wind power generator, a discharge means for discharging water in the caisson skeleton, and the caisson skeleton. It is characterized by comprising an injection means for injecting water or air toward the bottom of the water.

Further, in the invention according to claim 2 of the present invention, in addition to the configuration according to claim 1, the injection means includes a pipe extending from the upper part of the caisson skeleton to the bottom wall via a side wall, and at least the bottom. The pipe provided on the wall is characterized by having an injection hole for injecting water or air toward the bottom of the water.

Further, in the invention according to claim 3 of the present invention, in addition to the configuration according to claim 1 or 2, the discharge means discharges the sand when the caisson body is filled with sand and water. It is characterized by doing.

Further, in the invention according to claim 4 of the present invention, in addition to the configuration according to any one of claims 1 to 3, a working room is provided under the caisson skeleton, and the working room is filled. When concrete is cast, it is characterized in that an adhesion reduction sheet is attached to the ceiling and side walls of the work room.

Further, the invention according to claim 5 of the present invention includes a discharge step of discharging water in a caisson skeleton sunk in the water bottom as a basis of a wind power generation device, and water or air from the caisson skeleton to the water bottom. It has an injection step of injecting, and the buoyancy acting on the caisson skeleton by the discharge step is made larger than the own weight of the caisson skeleton, and water or air is ejected from the caisson skeleton toward the water bottom by the injection step. It is characterized in that the caisson skeleton is floated from the bottom of the water by injecting.

According to the first aspect of the present invention, when the caisson skeleton is moved or withdrawn, the water in the caisson skeleton is discharged by the discharging means, and water or air is injected from the caisson skeleton toward the bottom of the water by the injection means. As a result, by separating the state of attachment of the caisson skeleton to the bottom of the water, the caisson skeleton can be reliably and easily levitated, and the work efficiency can be significantly improved.

Further, according to the invention according to claim 2 of the present invention, in addition to the effect of the invention according to claim 1, the injection means includes a pipe extending from the upper part of the caisson skeleton to the bottom wall via the side wall, and at least. By providing the pipe provided on the bottom wall with an injection hole for injecting water or air toward the water bottom, it is possible to reliably and easily separate the state of attachment of the caisson skeleton to the water bottom.

Further, according to the invention according to claim 3 of the present invention, in addition to the effect according to claim 1 or 2, the discharging means discharges sand when the caisson body is filled with sand and water. As a result, it can be easily discharged by using a dredging pump or a sand pump as the discharge means.

Further, according to the invention according to claim 4 of the present invention, in addition to the effect of the invention according to any one of claims 1 to 3, a working room is provided under the caisson skeleton, and the working room is provided. When placing the filling concrete in the work room, the adhesion reduction sheet is attached to the ceiling and side walls of the work room, which makes it easier to separate the caisson skeleton and the filling concrete when moving or withdrawing the caisson skeleton. it can.

Further, according to the invention according to claim 5 of the present invention, the buoyancy acting on the caisson skeleton by the discharge step is made larger than the own weight of the caisson skeleton, and water or air is discharged from the caisson skeleton toward the bottom of the water by the injection step. By injecting and floating the caisson skeleton from the bottom of the water, the caisson skeleton can be reliably and easily lifted from the bottom of the water, and the work efficiency can be greatly improved.

It is a system diagram which shows the structure of the caisson for a wind power generation device which concerns on 1st Embodiment of this invention. It is an enlarged cross-sectional view which shows the laid state of the caisson skeleton of FIG. It is a system diagram which shows the structure of the caisson for a wind power generation device which concerns on 2nd Embodiment of this invention. It is an enlarged cross-sectional view which shows the laid state of the caisson skeleton of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a system diagram showing a configuration of a caisson for a wind power generator according to the first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a laid state of the caisson skeleton of FIG.

The wind power generation device shown in FIG. 1 shows an example of being applied to an offshore wind power generation device installed on a caisson skeleton submerged on the seabed. Further, the caisson for the wind power generation device according to the present embodiment is constructed by the installation caisson method.

As shown in FIG. 1, the offshore wind turbine generator 1 has a blade 2, and the blade 2 is rotatably installed at the upper end of the tower body 3. The offshore wind power generator 1 is installed on the upper surface of the caisson skeleton 4 by fixing the lower end of the tower body 3 to the upper surface of the caisson skeleton 4. The caisson skeleton 4 is housed with loaded water inside and is sunk on the seabed (water bottom) as the foundation of the offshore wind power generation device 1. The loaded water is water contained in the caisson skeleton 4 in order to increase the weight of the caisson skeleton 4.

The caisson skeleton 4 is composed of, for example, an RC (Reinforced Concrete) structure, a PC (Prestressed Concrete) structure, a steel-concrete composite structure, or the like, and in the present embodiment, the entire shape is formed in a quadrangular container shape. The caisson skeleton 4 includes a quadrangular bottom wall 5, a side wall 6 that rises integrally in the vertical direction from the outer peripheral end of the quadrangular bottom wall 5, and an upper wall 7 that closes the upper opening of the side wall 6. In the present embodiment, the upper portion and the upper wall 7 of the side wall 6 are located above the sea surface and are exposed from the sea surface. A hatch 8 is provided on the upper wall 7 so as to be openable and closable, and by opening the hatch 8, the inside and the outside of the caisson skeleton 4 are in a communicating state.

An air supply pipe 9 and a drainage pipe 12 penetrate through the upper wall 7 of the caisson skeleton 4. One end of the air supply pipe 9 extends slightly downward in the vertical direction in the caisson skeleton 4, and the other end is connected to a compressor (or an air compressor, the same applies hereinafter) 10. By driving the compressor 10, compressed air is supplied into the caisson skeleton 4 through the air supply pipe 9. An on-off valve 11 is provided in the air supply pipe 9 on the upstream side of the caisson skeleton 4.

One end of the drainage pipe 12 extends to the vicinity of the bottom wall 5 in the caisson skeleton 4, and the other end extends to the outside of the caisson skeleton 4. The loaded water contained in the caisson skeleton 4 can be drained from the drain pipe 12. An on-off valve 14 is provided in the drainage pipe 12 outside the caisson skeleton 4.

As the compressor 10, for example, a compressor installed on a work boat is used. The air supply pipe 9, the compressor 10, and the drain pipe 12 constitute a discharge unit 15 as a discharge means of the present embodiment. A drainage pump may be connected to the other end of the drainage pipe 12 and the drainage pump may be driven to drain the loaded water in the caisson skeleton 4.

In this embodiment, one end of the pipe 16 extends from the upper part of the caisson skeleton 4 to the bottom wall 5 via the side wall 6, and the other end of the pipe 16 is connected to a supply pump 17 for supplying water or air. .. In the pipe 16 located at the lower part of the side wall 6 and the bottom wall 5, a plurality of injection holes 18 with check valves are installed at regular intervals toward the seabed. By driving the supply pump 17, water or air is injected from the plurality of injection holes 18 toward the seabed through the pipe 16. The pipe 16, the supply pump 17, and the plurality of injection holes 18 constitute an injection unit 19 as an injection means of the present embodiment. As the supply pump 17, for example, a pump installed on a work boat is used like the compressor 10.

On the other hand, on the seabed where the caisson skeleton 4 is installed, a ground improvement unit 20 is provided to improve the ground when the ground is soft. On the ground improvement section 20, a foundation mound 21 is constructed like a trapezoidal stage by a large number of rubble stones. As shown in FIG. 2, a caisson skeleton 4 is installed on the foundation mound 21 via a friction increasing sheet 25. The foundation mound 21 is covered with a covering stone 22 from the lower portion to the lower side surface of the caisson skeleton 4. A plurality of rooting blocks 23 are further stacked on the covering stone 22 on the foundation mound 21.

Next, a method of moving and withdrawing the caisson for the wind power generation device according to the present embodiment will be described.

First, the blade 2 and the tower body 3 of the offshore wind power generation device 1 and the other superstructures of the offshore wind power generation device 1 are disassembled and removed.

Next, in the discharge step, the loaded water in the caisson skeleton 4 is discharged. Specifically, the compressor 10 is driven to supply air from the air supply pipe 9 into the caisson skeleton 4, and the loaded water contained in the caisson skeleton 4 is discharged from the drain pipe 12. Alternatively, the on-off valve 11 of the air supply pipe 9 is opened, and the loaded water in the caisson skeleton 4 is pumped out from the drain pipe 12 to empty the caisson skeleton 4.

Then, since the inside of the caisson skeleton 4 is emptied, the buoyancy acting on the caisson skeleton 4 becomes larger than the weight of the caisson skeleton 4, and the caisson skeleton 4 can be levitated. The surfaced caisson skeleton 4 can be towed and moved by a ship or the like.

Here, if the inside of the caisson skeleton 4 is emptied but does not ascend, as shown in FIG. 2, the adhesive force between the caisson skeleton 4 and the rooting block 23 or between the caisson skeleton 4 and the foundation rubble 21 An injection step is performed in order to reduce the adhesive force with the laid friction increasing sheet 25.

In this injection step, the supply pump 17 is driven to send air or water through the pipe 16, and the air or water is injected from the plurality of injection holes 18 to the seabed caisson block 23 and the friction increasing sheet 25. These adhered states are separated so that the caisson skeleton 4 is levitated.

Further, after the caisson skeleton 4 is towed and moved, the rooting block 23, the covering stone 22, and the foundation mound 21 are excavated and removed to restore the state before the installation of the offshore wind power generation device 1.

In order to cope with the insufficient weight of the caisson skeleton 4, when both sand and water are pre-filled in the caisson skeleton 4, a hatch 8 capable of countering the air pressure in the caisson skeleton 4 is opened. A sand pump (not shown) is introduced into the caisson skeleton 4 from the hatch 8.

By driving the sand pump charged into the caisson skeleton 4, the sand in the caisson skeleton 4 is discharged to the outside of the caisson skeleton 4, and then the water in the caisson skeleton 4 is discharged through the drain pipe 12 in the same manner as described above. To do.

As described above, in the present embodiment, the loaded water in the caisson skeleton 4 is discharged from the discharge unit 15 when the caisson skeleton 4 is moved or withdrawn, and the injection unit 19 discharges the loaded water in the caisson skeleton 4 from the caisson skeleton 4 to the root consolidation block 23 and friction. By injecting water or air toward the augmenting sheet 25, the caisson skeleton 4 can be reliably and easily levitated by separating the adhered state of the caisson skeleton 4 to the rooting block 23 and the friction increasing sheet 25. It is possible to greatly improve work efficiency.

Further, in the present embodiment, the injection portion 19 includes a pipe 16 extending from the upper portion of the caisson skeleton 4 to the bottom wall 5 via the side wall 6, and is rooted in the pipe 16 provided below the bottom wall 5 and the side wall 6. By having the injection holes 18 for injecting water or air toward the compaction block 23 and the friction increasing sheet 25, the state of attachment of the caisson skeleton 4 to the root compaction block 23 and the friction increasing sheet 25 can be reliably and easily separated. be able to.

Further, in the present embodiment, when the caisson skeleton 4 is filled with sand and water, the discharge unit 15 discharges the sand so that the discharge unit 15 can be easily discharged to the discharge unit 15 by using a dredging pump. Can be done.

Further, in the present embodiment, the buoyancy acting on the caisson skeleton 4 by the discharge step is made larger than the own weight of the caisson skeleton 4, and the caisson skeleton 4 is used to increase the friction from the caisson skeleton 4 to the seabed. By injecting water or air toward the sheet 25 to lift the caisson skeleton 4 from the rooting block 23 and the friction increasing sheet 25, the caisson skeleton 4 is reliably and easily lifted from the rooting block 23 and the friction increasing sheet 25. It can be levitated to the surface, and work efficiency can be greatly improved.

In the present embodiment, an example in which the injection holes 18 are provided in the pipes 16 arranged on the bottom wall 5 and the side wall 6 has been described, but the present invention is not limited to this, and injection is performed on at least the pipes 16 provided on the bottom wall 5. The hole 18 may be provided.

[Second Embodiment]
FIG. 3 is a system diagram showing a configuration of a caisson for a wind power generation device according to a second embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view showing a laid state of the caisson skeleton of FIG.

The same parts as those in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted. Further, the caisson for the wind power generation device of the present embodiment is constructed by the pneumatic caisson method. Further, FIG. 3 shows a state before placing the filling concrete in the work room, and FIG. 4 shows a state after placing the filling concrete in the work room.

As shown in FIG. 3, the caisson skeleton 4A is sunk with its lower portion embedded in the ground 30. The upper portion of the side wall 6 and the upper wall 7 of the caisson skeleton 4A are located above the sea surface and are exposed from the sea surface as in the first embodiment. The caisson skeleton 4A is provided with a working chamber 31 at the lower portion, and a side wall of the working chamber 31 is formed at a blade edge portion 32. One end of the air supply pipe 33 extends into the work room 31, and a compressor (or an air compressor, the same applies hereinafter) 34 is connected to the other end of the air supply pipe 33. By driving the compressor 34, compressed air is supplied into the working room 31 through the air supply pipe 33. An on-off valve 35 is provided in the air supply pipe 33 on the upstream side of the caisson skeleton 4A.

As shown in FIG. 4, the caisson skeleton 4A removes the protrusions in the work room 31 before placing the filled concrete 36 in the work room 31 at the completion of the laying, and removes the protrusions in the work room 31 and the ceiling of the work room 31. After attaching the adhesion reduction sheet 37 to the inner surface of the blade edge portion 32 which is the side wall, the filling concrete is placed.

Next, a method of moving and withdrawing the caisson for the wind power generation device according to the present embodiment will be described.

Similar to the first embodiment, first, the blade 2 and the tower body 3 of the offshore wind power generation device 1 and the other superstructures of the offshore wind power generation device 1 are disassembled and removed.

Next, in the discharge step, the loaded water in the caisson skeleton 4A is discharged. Specifically, the compressor 10 is driven to supply air from the air supply pipe 9 into the caisson skeleton 4A, and the loaded water contained in the caisson skeleton 4A is discharged from the drain pipe 12. Alternatively, the on-off valve 11 of the air supply pipe 9 is opened, and the loaded water in the caisson skeleton 4A is pumped out from the drain pipe 12 to empty the caisson skeleton 4A.

Since the inside of the caisson skeleton 4A is emptied, the buoyancy acting on the caisson skeleton 4A becomes larger than the resultant force between the weight of the caisson skeleton 4A and the peripheral frictional force in contact with the caisson skeleton 4A, and the caisson skeleton 4A floats. Can be made to. The surfaced caisson skeleton 4A can be towed and moved by a ship or the like.

Here, if the inside of the caisson skeleton 4A is emptied but does not ascend, the compressor 34 is driven to send compressed air from the air supply pipe 33 into the working room 31 of the caisson skeleton 4A, and if necessary, the air pressure in the working room 31 is reduced to water pressure. The caisson skeleton 4A can be levitated by raising it to h or more.

Further, if the caisson skeleton 4A still does not float, air or water is sent from the pipe 16 and air is sent from the plurality of injection holes 18 toward the seabed in order to reduce the peripheral frictional force between the caisson skeleton 4A and the ground 30 on the seabed. Alternatively, by injecting water, these adhered states can be separated and the caisson skeleton 4A can be levitated.

In order to ensure the ground bearing capacity, when the filled concrete 36 is placed in the work room 31 when the caisson skeleton 4A has been laid down, the protrusions in the work room 31 are removed before the placement. After attaching the adhesion reduction sheet 37 to the ceiling and the cutting edge portion 32 in the work room 31, the filling concrete 36 is placed.

When moving or withdrawing the caisson skeleton 4A, air or water is sent from the pipe 16 at the same time as the procedure for emptying the inside of the caisson skeleton 4A or at the same time as the procedure for emptying the inside of the caisson skeleton 4A, and a plurality of injection holes 18 By injecting air or water toward the adhesion reduction sheet 37, the adhesion force between the filling concrete 36 of the work room 31 and the caisson skeleton 4A can be reduced, and the caisson skeleton 4A can be easily levitated.

In this case, the filling concrete 36 is placed in the work room 31, or even if it is not placed, air or water is sent from the pipe 16 and air or water is injected from the plurality of injection holes 18. As a result, the caisson skeleton 4A can be effectively levitated.

In order to cope with the insufficient weight of the caisson skeleton 4A, when sand and water are pre-filled in the caisson skeleton 4A, a sand pump (not shown) is introduced from the hatch 8 capable of countering the pressure in the caisson skeleton 4A. By driving this sand pump, the sand in the caisson skeleton 4A is discharged to the outside of the caisson skeleton 4A, and then the water in the caisson skeleton 4A is discharged through the discharge pipe 12.

Therefore, in the present embodiment, the working room 31 is provided under the caisson skeleton 4A, and when the filled concrete 36 is placed in the working room 31, the blade edge which is the ceiling and the side wall in the working room 31. Since the adhesion reduction sheet 37 is attached to the portion 32 in advance, the caisson skeleton 4A and the filling concrete 36 can be easily separated when the caisson skeleton 4A is moved or withdrawn.

Further, in the present embodiment, when the caisson skeleton 4A is moved or withdrawn, the loaded water in the caisson skeleton 4A is discharged from the discharge unit 15, and the injection unit 19 discharges water or air from the caisson skeleton 4A toward the ground 30 on the seabed. By separating the state of attachment of the caisson skeleton 4A to the ground 30 by injecting the caisson skeleton 4A, the caisson skeleton 4A can be reliably and easily levitated, and the work efficiency can be significantly improved.

Further, in the present embodiment, the injection unit 19 includes a pipe 16 extending from the upper portion of the caisson skeleton 4A to the bottom wall 5 via the side wall 6, and the ground is provided in the pipe 16 provided below the bottom wall 5 and the side wall 6. By having the injection hole 18 for injecting water or air toward 30, the state of attachment of the caisson skeleton 4A to the ground 30 can be reliably and easily separated.

Further, in the present embodiment, the buoyancy acting on the caisson skeleton 4A by the discharge step is made larger than the own weight of the caisson skeleton 4A, and water or air is directed from the caisson skeleton 4A toward the ground 30 which is the sea floor by the injection step. By injecting the caisson skeleton 4A from the ground 30, the caisson skeleton 4A can be reliably and easily levitated from the ground 30, and the work efficiency can be significantly improved.

Since other configurations and actions and effects are the same as those in the first embodiment, the description thereof will be omitted.

It should be noted that the embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention.

In each of the above embodiments, the pipe 16 not only extends to the bottom wall 5 at one end, but also has a large number of branches arranged at the bottom wall 5 at one end of the pipe 16, and a plurality of injection holes are provided in each of these branch pipes. 18 may be provided. In this case, a large number of branch pipes may be arranged in a grid pattern.

Similarly, the pipe 16 may be arranged in a large number of branches at the lower part of the side wall 6, and a plurality of injection holes 18 may be provided in each of these branch pipes.

With this configuration, the number of injection holes 18 is increased and the injection holes 18 are scattered, so that the effect of separating the adhered state of the caisson skeletons 4 and 4A is further enhanced, and the caisson skeletons 4 and 4A are surely secured. And it can be easily surfaced.

Further, an example in which the caisson skeletons 4 and 4A are sunk on the seabed as the basis of the offshore wind power generation device 1 of each embodiment has been described, but the present invention is not limited to this and can be applied to the case where the caisson skeletons 4 and 4A are sunk on the lake bottom. Is.

Further, in each of the above embodiments, an example in which the entire shape of the caisson skeletons 4 and 4A is formed in a square container shape has been described, but the present invention is not limited to this, and the caisson skeletons 4 and 4A are formed in a circular container shape, an elliptical container shape, or a polygonal container shape. It may be a thing.

1 Offshore wind power generator 2 Blade 3 Tower 4 Caisson skeleton 4A Caisson skeleton 5 Bottom wall 6 Side wall 7 Upper wall 8 Hatch 9 Air supply pipe 10 Compressor 11 On-off valve 12 Drainage pipe 14 On-off valve 15 Discharge section
16 Piping 17 Supply pump 18 Injection hole 19 Injection part (injection means)
20 Ground improvement part 21 Foundation mound 22 Cover stone 23 Root consolidation block 25 Friction increase sheet 30 Ground 31 Work room 32 Blade edge 33 Air supply pipe 34 Compressor 35 On-off valve 36 Filled concrete 37 Adhesion reduction sheet h Water pressure

Claims (5)

The caisson skeleton that is sunk on the bottom of the water as the foundation of the wind power generator,
The drainage means for draining the water in the caisson body and
An injection means for injecting water or air from the caisson skeleton toward the bottom of the water.
Caisson for wind power generators characterized by being equipped with. The injection means includes a pipe extending from the upper part of the caisson skeleton to the bottom wall via a side wall, and at least the pipe provided on the bottom wall has an injection hole for injecting water or air toward the water bottom. The caisson for a wind power generator according to claim 1. The caisson for a wind power generation device according to claim 1 or 2, wherein the discharge means discharges the sand when the caisson body is filled with sand and water. A claim that a work room is provided under the caisson skeleton, and when filling concrete is placed in the work room, an adhesion reduction sheet is attached to the ceiling and side walls of the work room. The caisson for a wind power generator according to any one of 1 to 3. A discharge process that discharges the water inside the caisson skeleton that is sunk on the bottom of the water as the basis of the wind power generator
It has an injection step of injecting water or air from the caisson skeleton to the water bottom.
The buoyancy acting on the caisson skeleton by the discharge step is made larger than the own weight of the caisson skeleton, and water or air is injected from the caisson skeleton toward the water bottom by the injection step to inject the caisson skeleton from the water bottom. A method of ascending a caisson for a wind power generator, which is characterized by ascending.

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