JP2015077858A - Float type windmill mooring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a float type windmill mooring device in which assembly and maintenance work on ocean are reduced as possible, and the windmill mooring device is assembled in a dock and then transferred and installed on an installation location, and the maintenance work can be performed safely after being transferred in the dock, and the mooring device reduces position deviation due to water pressure caused by tidal current, wind force, and reduces tension variation of a mooring cable for reducing size of a float body and a weight for achieving significant cost reduction.SOLUTION: The float type windmill mooring device is configured so that a pole 2 extending upward is disposed on a base part 1 having floating force, and a windmill apparatus 3 is disposed on the pole, and plural float body arm members 4 implanted by being stretched from the base part in a horizontal direction, and plural weight arm members 6 stretched from a center part 8 of weight installed on an ocean bottom in a horizontal direction are respectively coupled by main mooring cables 9. A center part of the float body arm member and the weight is coupled by an auxiliary mooring cable 10.

Description

  TECHNICAL FIELD The present invention relates to a floating wind turbine mooring device installed mainly on the ocean where the water depth is deep, and more particularly for floating bodies and mooring by reducing the movement of the position of the floating body and reducing the fluctuation of the tension applied to the mooring line. The present invention relates to a floating-type windmill mooring device that enables downsizing and cost reduction of the weight.

  Wind power, which is considered to be the most effective of renewable natural energy, is limited in terms of its development on the ground due to noise and landscape restrictions. In the future, installation on a wide ocean will be the fastest way to solve the problem. In particular, if it is a floating type that can be installed even in deep waters, it is blessed with ample space and a stable wind, and there are few noise and landscape restrictions as described above. However, since large waves are generated depending on the weather conditions, we are now taking measures to prevent shaking by devising the shape of the floating body itself. Furthermore, since the cost required for installation increases at sea, technology to reduce this is important, but this proposal also includes a solution.

JP 2009-018671 A Japanese Patent Application No. 2012-253844 As a typical one, it is called a spar type as shown in the above-mentioned document, and floats as if many parts of a vertically long floating body are in the water, and the lower part is fixed to the seabed with chains, steel cords, etc. It is of the method. In addition, a so-called tendon system has been proposed in which a plurality of floating bodies connected to a weight installed on the seabed are connected by a mooring line, and the mooring line is tensioned by the buoyancy of the floating body to stabilize the position from the bottom of the water.

  However, with the spar type, it is extremely difficult to move in shallow water, so it is necessary to assemble at the installation site offshore at the installation site as a separate part at the time of manufacture, and the work is limited to when it is quiet without waves. Still, it is a lot of work. In addition, once installed, it is difficult to move during maintenance work, so it becomes a dangerous offshore work, and there is a disadvantage that the work cost in both installation and maintenance increases. In addition, the vibration caused by the waves is relatively large, and it is expected that the operation in bad weather will be limited when applied to a propeller type windmill.

  In the tendon method, when the water surface rises and falls due to waves, the buoyancy generated in the floating body fluctuates greatly, the tension change of the mooring line is large, and the holding force against the horizontal force generated by the water pressure due to wind force or tidal current is small In order to prevent this, it is necessary to improve the structural strength around the mooring line, and the weight of the necessary weight to be installed on the seabed. As a result, the cost increases.

In the former, assembling and maintenance work on the unstable ocean is reduced as much as possible, and the completed product is transferred to the installation location and installed in the dock, and maintenance work can also be transferred to the dock and performed in a safe state. What is desired is not the best answer.
The latter has a large position movement due to the small holding force against the horizontal force generated by the wind pressure or the water pressure caused by tidal currents, and is advantageous for the installation in the field, but the tension fluctuation of the wire is large. There are many factors that increase the cost due to the large size of the floating body and weight, which increases the structural strength around the mooring line.

  The patent application of Japanese Patent Application No. 2012-253844 is the applicant's patent application, but a small device is installed in a relatively shallow lake or the like because of the holding method with a loosely moored mooring line instead of a tension mooring line like Tendon Although it is inexpensive and effective, there is a possibility that sufficient performance cannot be exhibited when there is a water flow or when the water level fluctuation is large.

Floating type windmill mooring device is installed so that assembling and maintenance work on the ocean is reduced as much as possible and the finished product in the dock is transferred to the installation site and the maintenance work can also be transferred to the dock and performed in a safe state. Floating-type windmill mooring device that makes it possible to reduce the position movement caused by water pressure due to wind power and tidal currents, reduce the tension fluctuation of the mooring cable, downsize the floating body and weight, and greatly reduce the cost Is to provide.

  A first means for solving the above-mentioned problems of the present invention is to eliminate a plurality of floats arranged around the base in the tendon system and collect them at the center, and a plurality of floating arms planted by extending horizontally from the base It is an object of the present invention to provide a floating wind turbine mooring device that solves the above problems by connecting a member and a plurality of weight arm members extending in the horizontal direction from the center of the weight installed on the seabed, respectively.

  The second means for solving the above-mentioned problems of the present invention is to connect the floating arm member and the center of the weight with an auxiliary mooring line, thereby reducing the position movement caused by water pressure due to wind force or tidal current, and mooring. It is an object of the present invention to provide a floating-type windmill mooring device that can greatly reduce the cost by reducing the tension variation of the rope and reducing the size of the floating body and the weight.

  The first effect of the present invention is that a float is gathered in the center and a plurality of floating arm members planted by extending horizontally from the base and a plurality of weights extending horizontally from the center of the weight installed on the seabed. By connecting the weight arm members with the main mooring lines, the movement resistance when towing the floating wind turbine mooring device itself can be greatly reduced. In addition, since the construction of the towed vessel when towing to the installation site after completing the device at the dock does not require a special device for storing multiple floats in the tendon method, the cost burden is reduced. As a result, it is possible to reduce dangerous offshore work at the installation site and switch to safe work in the dock.

  The second effect of the present invention is that the floating arm member and the center of the weight are connected by an auxiliary mooring line, thereby reducing the position movement caused by the water pressure due to wind force or tidal current, and reducing the tension fluctuation of the mooring line. Thus, it is possible to provide a floating type wind turbine mooring device that can reduce the size of the floating body and the weight and significantly reduce the cost.

FIG. 1 is a schematic side view showing a two-dimensional structure of the floating wind turbine mooring device of the present invention. FIG. 2 is a schematic side view showing a two-dimensional structure of the tendon type floating wind turbine mooring device. FIG. 3 is a schematic side view showing a two-dimensional structure of another embodiment of the floating wind turbine mooring device of the present invention.

  2 shows an embodiment in which the floating wind turbine mooring device of the present invention is two-dimensionalized for simplicity of explanation.

FIG. 1 is a schematic side view showing a two-dimensional structure of the floating wind turbine mooring device of the present invention. Although it is originally a three-dimensional object, it is two-dimensionally made flat to clarify the explanation.
In FIG. 1, a pole 2 is provided on the upper part of a base 1 floating on the water, and a windmill device 3 is provided on the upper part. In the figure, it is of an upwind type, but is not limited to this type. Reference numeral 4 denotes a floating arm member planted in the horizontal direction from the base 1, and a coupling member 5 is provided at the tip of the floating arm member 4. The coupling member 5 does not have buoyancy in particular, but may have some buoyancy depending on the volume. 6 is a weight arm member installed on the seabed, 7 is a weight coupling member provided at a position corresponding to the coupling member 5, and 8 is a weight center portion. Reference numeral 9 denotes a main mooring line connecting the connecting member 5 and the weight connecting member 7, and reference numeral 10 denotes a sub mooring line connecting the connecting member 5 and the weight central portion 8. In FIG. 1, the sub mooring line 10 connects the connecting member 5 and the weight central portion 8, but conversely, even if the lower portion of the base portion 1 and the weight connecting member 7 are connected, theoretically substantially the same effect is obtained. Can be obtained. W is the force received by the windmill device 3 by the wind, L is the force received by the entire mooring device by the tidal current, and H is the height of the wave.
[Action]

The operation of the floating wind turbine mooring device of the present invention shown in the above embodiment will be described.
In FIG. 1, when the wind hits the windmill device 3 and a force of W is applied, the mooring device has a horizontal force W and a height from the coupling portion between the coupling member 7 of the windmill device 3, the main mooring line 9, and the sub mooring line 10. Receive moment by The horizontal force W is supported by the difference in tension between the left and right sub mooring lines 10, and the moment can be supported by the difference in tension between the left and right main mooring lines 9, so that the mooring device does not flow or tilt. . However, it is a condition that a sufficient initial tension is applied to the main mooring line 9 due to the buoyancy of the base 1. In order to satisfy the condition, the weight of the weight coupling member 7 and the weight central part 8 is the above-mentioned weight. Sufficient weight is required so that the initial tension and the moment do not lift.

  Further, the force L applied to the mooring device due to the fluid resistance caused by the tidal current tends to push the mooring device to the side in the same manner as W, but does not cause a moment like W. Therefore, the pushing force by L is supported by the difference in tension between the left and right sub mooring lines 10. In this case, it is not necessary to apply initial tension to the sub mooring line 10 if some lateral movement is allowed.

  Regarding the shaking caused by the waves, the change in the draft of the base 1 floating on the water is not a left and right shaking moment but is added as a tension change distributed to the left and right main mooring lines 9, so the weight coupling member 7 alone There is no need to support it. In particular, since the sub mooring line 9 is coupled to the weight central portion 8, the weight of the entire weight supports the change in tension, and accordingly, the weight of the weight can be reduced.

  In FIG. 1 and the above description, although it is a two-dimensional shape, there are actually a plurality of floating arm members 4 that are radially implanted from the base 1 in the horizontal direction, A coupling member 5 is provided at each end of the floating arm member 4. A plurality of weight arm members 6 are also provided at the seafloor position corresponding to the coupling member 5, and are provided radially from the weight center portion 8. Accordingly, the same function can be obtained in a direction perpendicular to the paper surface in FIG.

FIG. 2 is a schematic side view showing a two-dimensional structure of a conventional tendon type floating wind turbine mooring device.
In FIG. 2, the pole 12 is provided in the upper part of the base 11 on a water surface, and the windmill apparatus 13 is provided in the upper part. Reference numeral 14 denotes an arm member implanted in the horizontal direction from the base 1, and a float member 15 is provided at the tip of the arm member 14. The float member 15 has sufficient buoyancy according to the volume. Reference numeral 17 denotes a weight coupling member provided at a position corresponding to the float member 15. A mooring line 19 connects the connecting member 15 and the weight connecting member 17. W is the force received by the wind turbine device 13 by the wind, L is the force received by the entire mooring device by the tidal current, and H is the height of the wave.

In the case of FIG. 2, when a wind hits the windmill device 13 and a force of W is applied, the mooring device receives a horizontal force W and a moment due to the height from the coupling portion between the coupling member 17 of the windmill device 13 and the mooring line 19.
The horizontal force W has an increase in the buoyancy of the float member 15 caused by the geometrical distance change d from the water surface caused by the lateral movement of the mooring device, and the lateral force caused by the increase in the buoyancy and the inclination of the mooring line 19. Supported by directional force balance. Therefore, the lateral movement by W is already folded and cannot be eliminated. Further, the moment can be supported by the change in tension of the left and right mooring lines 19.

  Further, the force L applied to the mooring device due to the fluid resistance due to the tidal current increases the buoyancy of the float member 15 caused by the distance change d from the geometrical water surface caused by the lateral movement of the mooring device as in the case of the wind force W. And is supported by a balance of lateral forces generated by the increase in buoyancy and the inclination of the mooring line 19. Therefore, the lateral movement by W is already folded and cannot be eliminated.

  Regarding the shaking caused by the wave, if there is a big wave because the change in the draft of the float member 15 is directly added as the change in the tension of the mooring line 19, the weight coupling member 17 can support the weight alone so that it does not lift up. It is necessary to have.

FIG. 3 is a schematic side view showing a two-dimensional structure of another embodiment of the floating wind turbine mooring device of the present invention.
In FIG. 3, an intermediate frame 31 is provided between the base 1 floating on the water and the weight arm member 6 installed on the seabed, and is fixed to the outer peripheral portion 32 so that the main mooring line 9 passes therethrough. The sub mooring line 10 is fixed as it penetrates and the tip is fixed to the weight coupling member 7. In the case of the embodiment shown in FIG. 3, the water depth is suitable for a state where the water depth is twice that in the case of FIG.
Since the inclination angle of the sub mooring line 10 is the same as that of the embodiment shown in FIG. 1, the position movement of the float is limited by the action of the sub mooring line 10 by the force W received by the wind and the force L received by the tidal current, and the embodiment shown in FIG. As in the case of, the position of the float does not increase in proportion to the water depth. Further, in order to prevent the base 1 from being twisted in the rotational direction due to the wind turbine torque or the like, it is omitted because it has been described as being two-dimensional in FIGS. 1 and 3, but is a coupling member arranged on the circumference. In addition to the weight coupling member 7 arranged on the circumference in the same manner as 5, it is added that it can be prevented by adding a mooring line that couples adjacent ones to each other.

  As apparent from the above description, the floating wind turbine mooring device of the present invention can prevent the position movement by the force due to the wind and tidal current, and can also reduce the force applied to the weight of the seabed by the inclination moment due to the wind force and the wave. Can be greatly reduced, making production easier and reducing costs. In the case where an intermediate frame is provided in the middle of the mooring line, the effect of reducing the position movement increases as the depth of the seabed becomes deeper than the conventional method. In addition, since the floats are gathered in the center, the towed vessel when towing can remove the function of accommodating multiple floats required by the conventional method, and the structure can be greatly simplified, so it can be reduced in cost. Towing is possible, and the manufacturing and maintenance work at the dock can be expanded, which can greatly improve safety, and its industrial effect is extremely remarkable.

DESCRIPTION OF SYMBOLS 1 Base 2 Pole 3 Windmill apparatus 4 Floating arm member 5 Coupling member 6 Weight arm member 7 Weight coupling member 8 Weight center part 9 Main mooring cable 10 Sub mooring cable 11 Base 12 Pole 13 Windmill apparatus 14 Arm member 15 Float member 17 Weight coupling member 19 Mooring line 20 Large diameter part 21 Hook 31 Intermediate frame 32 Outer peripheral part 33 Central part W Force received by wind L Force received by tidal current Height of wave d Change in distance from water surface

Claims (3)

A base with buoyancy is provided with a pole extending upward, a windmill device is provided on the top of the pole, and installed on the seabed with the connecting members at the tip of a plurality of floating arm members that are radially extended from the base and planted A floating-type windmill mooring device comprising a plurality of weight arm members extending radially from the center portion of the weights connected by a main mooring line.   The floating-type windmill mooring device according to claim 1, wherein the floating-type windmill mooring device is configured such that the connecting member at the tip of the floating arm member and the center of the weight are connected by an auxiliary mooring line.   2. A floating type windmill mooring according to claim 1, wherein the base has buoyancy and a plurality of weight arm members extending radially from the center of the weight are connected by an auxiliary mooring line. apparatus.

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