JP7353138B2 - Caissons for wind power generators and their floating method - Google Patents

Description

The present invention relates to a caisson for a wind power generation device that is sunk to the bottom of water as a foundation of the wind power generation device, and a method for floating the same.

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

Further, some offshore wind power generators use a caisson as the foundation, as described in Patent Document 1. In this foundation using a caisson, a friction-increasing mat is installed on the bottom of the caisson to increase frictional resistance, and a high-density material such as metal slag or ore is used as the filling material to increase the sliding resistance of the caisson. .

Japanese Patent Application Publication No. 2006-322400

As mentioned above, when pile foundations are used as the foundations of offshore wind power generation equipment, it may be difficult to remove all of the pile foundations reliably during work, and large offshore facilities are required to pull them out. Therefore, there is a problem that the work cost is high. Furthermore, when cutting the pile foundation underwater, there was a problem in terms of safety of the cutting operation.

Furthermore, in the case of using the caisson described in Patent Document 1, when the caisson is floated during movement and withdrawal, it is necessary to discharge the filling material of high specific gravity from inside the caisson, which reduces work efficiency. The problem is that it's 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 generation device and a method for levitating the same, which can reliably and easily levitate a caisson frame when moving or withdrawing the caisson frame. shall be.

In order to solve the above problems, the invention according to claim 1 of the present invention includes a caisson frame that is sunk to the bottom of the water as a foundation of a wind power generation device, and a caisson frame that drains water inside the caisson frame and A discharge means for introducing air , and an injection means for injecting water or air from the caisson body toward the bottom of the water, the injection means extending vertically within the side wall from the top of the caisson body. side wall piping; and bottom wall piping extending inward from the lower end of the side wall piping through a bottom wall that closes the bottom opening of the caisson frame, and at least the bottom wall piping is configured to direct water or water toward the bottom of the water. The caisson body is characterized by having a plurality of injection holes that inject air to float the caisson frame above the water bottom .

Further, in addition to the structure described in claim 1 , the invention according to claim 2 of the present invention is characterized in that, when sand and water are filled in the caisson frame, the discharge means discharges the sand. It is characterized by

In addition, the invention according to claim 3 of the present invention provides a caisson frame that is sunk to the bottom of the water as a foundation of a wind power generator, a discharge means for discharging water in the caisson frame, and a discharge means for discharging water from the caisson frame toward the bottom of the water. and an injection means for injecting water or air, and a working chamber is provided below the caisson frame, and when pouring concrete is poured into the working chamber, adhesion to the ceiling and side walls of the working chamber is reduced. It is characterized by a sheet attached.

Further, the invention according to claim 4 of the present invention includes a discharge step of discharging water in a caisson frame sunk to the bottom of the water as a foundation of a wind power generator , and introducing air into the caisson frame; comprising: a side wall pipe extending vertically within the side wall from the top of the frame; and a bottom wall pipe extending inward from the lower end of the side wall pipe through the bottom wall that closes the bottom opening of the caisson frame; an injection step of injecting water or air to the bottom of the water from at least a plurality of injection holes in the bottom wall piping; Air is introduced to make the buoyant force acting on the caisson frame larger than the weight of the caisson frame itself, and water or air is injected from the caisson frame toward the water bottom in the injection step to cause the caisson frame to move toward the water bottom. The feature is that it floats up from the surface.

According to the invention set forth in claim 1 of the present invention, when the caisson frame is moved or withdrawn, the water inside the caisson frame is discharged by the discharge means, and water or air is injected from the caisson frame toward the bottom of the water by the injection means. By separating the state of adhesion of the caisson frame to the water bottom, the caisson frame can be reliably and easily floated, making it possible to significantly improve work efficiency.
Further, according to the invention set forth in claim 1 of the present invention, the injection means includes piping extending from the top of the caisson frame to the bottom wall via the side wall, and at least the piping provided on the bottom wall is directed toward the bottom of the water. By having an injection hole that injects water or air, it is possible to reliably and easily separate the caisson frame from adhering to the bottom of the water.

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

Further, according to the invention described in claim 3 of the present invention, a working chamber is provided below the caisson frame, and when filling concrete is placed in this working chamber, adhesion to the ceiling and side walls of the working chamber is reduced. By pasting the sheet, the caisson frame and the filling concrete can be easily separated when the caisson frame is moved or removed.

Further, according to the invention described in claim 4 of the present invention, the buoyancy acting on the caisson frame is made larger than the own weight of the caisson frame in the discharge process, and the water or air is directed from the caisson frame towards the bottom of the water in the injection process. By elevating the caisson frame from the water bottom by spraying it, the caisson frame can be reliably and easily lifted from the water bottom, making it possible to significantly improve work efficiency.

FIG. 1 is a system diagram showing the configuration of a caisson for a wind power generator according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing the caisson frame of FIG. 1 in a submerged state. FIG. 2 is a system diagram showing the configuration of a caisson for a wind power generator according to a second embodiment of the present invention. FIG. 4 is an enlarged sectional view showing the caisson frame of FIG. 3 in a submerged state.

Embodiments of the present invention will be described in detail below with reference to the drawings.

[First embodiment]
FIG. 1 is a system diagram showing the configuration of a caisson for a wind power generator according to a first embodiment of the present invention. FIG. 2 is an enlarged sectional view showing the caisson frame of FIG. 1 in a submerged state.

The wind power generation device shown in FIG. 1 is an example in which the wind power generation device is applied to an offshore wind power generation device installed on a caisson frame sunk on the seabed. Further, the caisson for a wind power generator according to the present embodiment is constructed by the installation caisson construction method.

As shown in FIG. 1, the offshore wind power generation device 1 has blades 2, and the blades 2 are rotatably installed at the upper end of the tower body 3. The lower end of this tower body 3 is fixed to the upper surface of the caisson frame 4, so that the offshore wind power generation device 1 is installed on the upper surface of the caisson frame 4. This caisson frame 4 accommodates load water inside and is sunk on the seabed (bottom of the water) as the foundation of the offshore wind power generation device 1. The load water is water contained in the caisson frame 4 in order to increase the weight of the caisson frame 4.

The caisson frame 4 is made of, for example, an RC (Reinforced Concrete) structure, a PC (Prestressed Concrete) structure, a steel-concrete composite structure, etc., and in this embodiment, the overall shape is formed into a rectangular container shape. The caisson frame 4 includes a rectangular bottom wall 5, a side wall 6 vertically rising integrally from the outer peripheral end of the rectangular bottom wall 5, and an upper wall 7 that closes an upper opening of the side wall 6. In this embodiment, the upper part of the side wall 6 and the upper wall 7 are located above the sea surface and exposed from the sea surface. A hatch 8 is provided in the upper wall 7 so as to be openable and closable, and by opening the hatch 8, the inside of the caisson frame 4 and the outside are brought into communication.

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

One end of the drain pipe 12 extends to the vicinity of the bottom wall 5 inside the caisson frame 4, and the other end extends to the outside of the caisson frame 4. Load water contained in the caisson frame 4 can be drained from this drain pipe 12. A drain pipe 12 outside the caisson frame 4 is provided with an on-off valve 14 .

The compressor 10 used is one installed on a work boat, for example. The air pipe 9, the compressor 10, and the drain pipe 12 constitute a discharge section 15 as a discharge means of this embodiment. Note that a drain pump may be connected to the other end of the drain pipe 12 and the loaded water in the caisson frame 4 may be drained by driving this drain pump.

In this embodiment, one end of the piping 16 extends from the top of the caisson frame 4 to the bottom wall 5 via the side wall 6, and the other end of the piping 16 is connected to a supply pump 17 that supplies water or air. . A plurality of injection holes 18 with check valves are installed in the pipe 16 located at the lower part of the side wall 6 and the bottom wall 5 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 piping 16. The piping 16, the supply pump 17, and the plurality of injection holes 18 constitute an injection section 19 as an injection means of this embodiment. As with the compressor 10, the supply pump 17 is installed, for example, on a work boat.

On the other hand, on the seabed surface where the caisson frame 4 is installed, if the ground is soft, a ground improvement section 20 is provided to improve the ground. A foundation mound 21 is constructed like a trapezoidal stage on this ground improvement section 20 using a large number of rubble stones. As shown in FIG. 2, the caisson frame 4 is installed on the foundation mound 21 with a friction increasing sheet 25 interposed therebetween. The foundation mound 21 is covered with a covering stone 22 from its lower part to the lower side of the caisson frame 4. A plurality of foot protection blocks 23 are further stacked on the covering stone 22 on the foundation mound 21.

Next, a method for moving and withdrawing the wind power generator caisson according to the present embodiment will be explained.

First, the blades 2 and tower body 3 of the offshore wind power generation device 1 and other upper structures of the offshore wind power generation device 1 are dismantled and removed.

Next, in the discharge step, the loaded water in the caisson frame 4 is discharged. Specifically, the compressor 10 is driven to send air into the caisson frame 4 from the air supply pipe 9, and the load water accommodated in the caisson frame 4 is discharged from the drain pipe 12. Alternatively, the inside of the caisson frame 4 is emptied by opening the on-off valve 11 of the air pipe 9 and pumping out the loaded water inside the caisson frame 4 from the drain pipe 12.

Then, since the inside of the caisson body 4 becomes empty, the buoyant force acting on the caisson body 4 becomes larger than the own weight of the caisson body 4, and the caisson body 4 can be floated. The floating caisson frame 4 can be towed and moved by a ship or the like.

Here, if the caisson body 4 does not float even after emptying, the adhesion force between the caisson body 4 and the foot protection block 23, or the amount of water laid between the caisson body 4 and the foundation mound 21, as shown in FIG. In order to reduce the adhesion force with the friction increasing sheet 25, an injection process is performed.

In this injection step, the supply pump 17 is driven to send air or water through the piping 16, and the air or water is injected from the plurality of injection holes 18 to the seabed, which is the foot protection block 23 and the friction increasing sheet 25. These adhering states are separated and the caisson frame 4 is made to float.

Further, after the caisson frame 4 is towed and moved, the foot protection blocks 23, covering stones 22, and foundation mounds 21 are excavated and removed to restore the state before the installation of the offshore wind power generation device 1.

In addition, in order to cope with the lack of dead weight of the caisson frame 4, if the caisson frame 4 is filled with both sand and water in advance, the hatch 8 that can counteract the atmospheric pressure inside the caisson frame 4 is opened. A sand pump (not shown) is introduced into the caisson frame 4 through the hatch 8.

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

As described above, in this embodiment, when the caisson frame 4 is moved or withdrawn, the load water inside the caisson frame 4 is discharged from the discharge part 15, and the water is discharged from the caisson frame 4 by the injection part 19 to the foot protection block 23 on the seabed and the friction The caisson frame 4 is reliably and easily floated by separating the state of adhesion of the caisson frame 4 to the foot protection block 23 and the friction increase sheet 25 by jetting water or air toward the increase sheet 25. This makes it possible to significantly improve work efficiency.

Further, in this embodiment, the injection part 19 includes a pipe 16 extending from the upper part of the caisson frame 4 to the bottom wall 5 via the side wall 6, and is rooted in the pipe 16 provided at the bottom of the bottom wall 5 and the side wall 6. By having the injection hole 18 that injects water or air toward the compacting block 23 and the friction increasing sheet 25, the adhesion state of the caisson frame 4 to the foot compacting block 23 and the friction increasing sheet 25 can be reliably and easily separated. be able to.

Furthermore, in this embodiment, when the caisson frame 4 is filled with sand and water, the discharge section 15 can easily discharge the sand by using a dredging pump. I can do it.

In addition, in this embodiment, the buoyant force acting on the caisson frame 4 is made larger than the own weight of the caisson frame 4 through the above-mentioned ejection process, and the buoyancy force acting on the caisson frame 4 is made larger than the own weight of the caisson frame 4 through the above-mentioned injection process, and the buoyancy force acting on the caisson frame 4 is moved from the caisson frame 4 to the foot protection block 23 on the seabed through the above-mentioned injection process. By injecting water or air toward the sheet 25 and lifting the caisson frame 4 from the foot protection block 23 and the friction increasing sheet 25, the caisson frame 4 can be reliably and easily removed from the foot protection block 23 and the friction increasing sheet 25. This makes it possible to significantly improve work efficiency.

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

[Second embodiment]
FIG. 3 is a system diagram showing the configuration of a caisson for a wind power generator according to a second embodiment of the present invention. FIG. 4 is an enlarged sectional view showing the caisson frame of FIG. 3 in a submerged state.

Note that the same parts as in the first embodiment are given the same reference numerals and redundant explanations will be omitted. Further, the caisson for a wind power generator according to the present embodiment is constructed using a pneumatic caisson construction method. Furthermore, FIG. 3 shows the state before the filling concrete is placed in the working chamber, and FIG. 4 shows the state after the filling concrete is placed in the working chamber.

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

As shown in FIG. 4, when pouring the filling concrete 36 in the working chamber 31 at the time of completion of sinking, the caisson frame 4A is constructed by removing protrusions in the working chamber 31 before pouring, and removing the projections from the ceiling of the working chamber 31 and An adhesion reducing sheet 37 is pasted on the inner surface of the blade mouth portion 32, which is the side wall, and then the filling concrete is placed.

Next, a method for moving and withdrawing the wind power generator caisson according to the present embodiment will be explained.

As in the first embodiment, first, the blades 2 and tower body 3 of the offshore wind power generation device 1 and the other upper structures of the offshore wind power generation device 1 are dismantled and removed.

Next, in the discharge step, the loaded water in the caisson frame 4A is discharged. Specifically, the compressor 10 is driven to supply air from the air pipe 9 into the caisson frame 4A, and the load water accommodated within the caisson frame 4A is discharged from the drain pipe 12. Alternatively, the inside of the caisson frame 4A is emptied by opening the on-off valve 11 of the air pipe 9 and pumping out the loaded water inside the caisson frame 4A from the drain pipe 12.

Then, as the inside of the caisson frame 4A becomes empty, the buoyant force acting on the caisson frame 4A becomes greater than the resultant force of the own weight of the caisson frame 4A and the frictional force on the circumferential surface where the caisson frame 4A is in contact, causing the caisson frame 4A to float. can be done. The floating caisson frame 4A can be towed and moved by a ship or the like.

Here, if the caisson body 4A does not float even after emptying, the compressor 34 is driven to send compressed air from the air pipe 33 into the working chamber 31 of the caisson body 4A, and if necessary, the pressure in the working chamber 31 is reduced to water pressure. The caisson frame 4A can be levitated by raising the caisson body 4A to above h.

Furthermore, if the caisson body 4A still does not float, air or water is sent from the piping 16 to reduce the circumferential friction force between the caisson body 4A and the seabed ground 30, and the air or water is sent from the plurality of injection holes 18 toward the seabed. Alternatively, by jetting water, these adhering states can be separated and the caisson frame 4A can be floated.

In addition, in order to ensure the ground bearing capacity, when pouring the filling concrete 36 in the working chamber 31 after completing the sinking of the caisson frame 4A, any protrusions in the working chamber 31 should be removed before pouring. After adhering the adhesion reducing sheet 37 to the ceiling and the cutting edge part 32 in the work room 31, the filling concrete 36 is placed.

When moving or withdrawing the caisson body 4A, air or water is sent from the piping 16 to the plurality of injection holes 18, following the procedure of emptying the inside of the caisson body 4A, or simultaneously with the procedure of emptying the inside of the caisson body 4A. By injecting air or water toward the adhesion reducing sheet 37, the adhesion force between the filling concrete 36 of the work chamber 31 and the caisson frame 4A can be reduced, and the caisson frame 4A can be easily floated.

In this case, whether the filling concrete 36 is placed in the work chamber 31 or even if it is not placed, air or water is sent from the piping 16 and air or water is injected from the plurality of injection holes 18. Thereby, the caisson frame 4A can be effectively levitated.

In addition, in order to cope with the lack of dead weight of the caisson frame 4A, if the caisson frame 4A is filled with sand and water in advance, a sand pump (not shown) is introduced from the hatch 8 that can counteract the air pressure inside the caisson frame 4A. By driving this sand pump, the sand in the caisson frame 4A is discharged to the outside of the caisson frame 4A, and then the water in the caisson frame 4A is discharged through the discharge pipe 12.

Therefore, in this embodiment, a working chamber 31 is provided below the caisson frame 4A, and when pouring concrete 36 into this working chamber 31, the cutting hole which is the ceiling and side walls of the working chamber 31 is By pasting the adhesion reducing sheet 37 on the portion 32 in advance, the caisson frame 4A and the filling concrete 36 can be easily separated when the caisson frame 4A is moved or withdrawn.

In addition, in this embodiment, when the caisson frame 4A is moved or withdrawn, the load water inside the caisson frame 4A is discharged from the discharge part 15, and the water or air is discharged from the caisson frame 4A toward the ground 30 on the seabed by the injection part 19. By injecting , the state of adhesion of the caisson frame 4A to the ground 30 is separated, thereby making it possible to reliably and easily levitate the caisson frame 4A, thereby greatly increasing work efficiency.

Further, in this embodiment, the injection unit 19 includes a pipe 16 extending from the upper part of the caisson frame 4A to the bottom wall 5 via the side wall 6, and the pipe 16 provided at the bottom of the bottom wall 5 and the side wall 6 is connected to the ground. By having the injection hole 18 that injects water or air toward the ground 30, the adhesion state of the caisson frame 4A to the ground 30 can be reliably and easily separated.

In addition, in this embodiment, the buoyant force acting on the caisson frame 4A is made larger than the own weight of the caisson frame 4A in the above-mentioned discharge process, and the water or air is directed from the caisson frame 4A toward the ground 30, which is the seabed, in the above-described injection process. By injecting the caisson body 4A to levitate it from the ground 30, the caisson body 4A can be reliably and easily levitated from the ground 30, making it possible to significantly improve work efficiency.

Note that the other configurations and effects are the same as those of the first embodiment, so their explanation will be omitted.

Note that the embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention.

In each of the embodiments described above, one end of the piping 16 does not simply extend to the bottom wall 5, but one end of the piping 16 is arranged in many branches at the bottom wall 5, and each of these branch pipes has a plurality of injection holes. 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 plurality 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 increases and the injection holes 18 are scattered, which further enhances the effect of separating the adhering state of the caisson frames 4, 4A, and securely secures the caisson frames 4, 4A. And it can be easily floated.

In addition, although an example has been described in which the caisson frames 4 and 4A are sunk on the seabed as the basis of the offshore wind power generation device 1 of each embodiment, the application is not limited to this and can also be applied when the caisson frames 4 and 4A are sunk on the bottom of a lake. It is.

Furthermore, in each of the above embodiments, an example was described in which the overall shape of the caisson frames 4, 4A was formed into a rectangular container shape, but the shape is not limited to this, and the caisson frames 4, 4A may be formed into a circular container shape, an elliptical container shape, or a polygonal container shape. It can be anything.

1 Offshore wind power generation equipment 2 Blades 3 Tower body 4 Caisson body 4A Caisson body 5 Bottom wall 6 Side wall 7 Top wall 8 Hatch 9 Air pipe 10 Compressor 11 On-off valve 12 Drain pipe 14 On-off valve 15 Discharge part (discharge means)
16 Piping 17 Supply pump 18 Injection hole 19 Injection part (injection means)
20 Ground improvement section 21 Foundation mound 22 Covering stone 23 Foot protection block 25 Friction increasing sheet 30 Ground 31 Working chamber 32 Cutting edge section 33 Air pipe 34 Compressor 35 On-off valve 36 Filling concrete 37 Adhesion reducing sheet h Water pressure

Claims (4)

A caisson frame that is sunk to the bottom of the water as the foundation of a wind power generator,
a discharge means for discharging water in the caisson frame and introducing air into the caisson frame ;
an injection means for injecting water or air from the caisson frame toward the bottom of the water ,
The injection means includes a side wall pipe that extends vertically within the side wall from the upper part of the caisson frame, and a bottom that extends inward from the lower end of the side wall pipe through the bottom wall that closes the bottom opening of the caisson frame. A wind power generation device comprising wall piping, wherein at least the bottom wall piping has a plurality of injection holes that inject water or air toward the water bottom to float the caisson frame from the water bottom. caisson. The caisson for a wind power generator according to claim 1, wherein the discharge means discharges the sand when the caisson frame is filled with sand and water . A caisson frame that is sunk to the bottom of the water as the foundation of a wind power generator,
a discharge means for discharging water within the caisson frame;
an injection means for injecting water or air from the caisson frame toward the bottom of the water,
A wind power generation system characterized in that a work chamber is provided below the caisson frame, and when pouring concrete is placed in the work chamber, an adhesion reduction sheet is pasted on the ceiling and side walls of the work chamber. Caissons for equipment. a discharge step of draining water in a caisson frame sunk to the bottom of the water as a foundation of a wind power generation device, and introducing air into the caisson frame;
a side wall pipe extending vertically within the side wall from the top of the caisson frame; and a bottom wall pipe extending inward from the lower end of the side wall pipe through the bottom wall that closes the bottom opening of the caisson frame. and an injection step of injecting water or air to the water bottom from at least a plurality of injection holes of the bottom wall piping,
The water in the caisson frame is discharged by the discharge process, air is introduced into the caisson frame to make the buoyant force acting on the caisson frame larger than the own weight of the caisson frame, and the injection process removes the water from the caisson frame. A method for floating a caisson for a wind power generator, characterized in that the caisson frame is floated from the water bottom by injecting water or air from the frame toward the water bottom.

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