JP2011251675A - Swing reducing device - Google Patents

Abstract

There is provided a vibration reducing device that more effectively suppresses rocking even with large rocking.
SOLUTION: A propeller 1 that is rotated by wind power, a tower 2 that rotatably supports the propeller, and a floating body 3 that mounts the tower are provided, and the floating body constitutes a floating excavation ship, and the rotation of the propeller To reduce the swing of the floating excavation ship. Waves are generated by wind in the ocean. By rotating the propeller with this wind, the swinging of the floating body due to waves is suppressed. That is, wind energy is converted into a damping force through the tower, and the swinging of the floating body is suppressed.
[Selection] Figure 1

Description

  The present invention relates to a vibration reduction device.

  Oil and gas mining in the ocean and the like is generally performed by a deck lifting type apparatus or a floating excavation ship. The deck raising / lowering device is a device having a platform on which excavation equipment is arranged and a leg fixed to the seabed or lake bottom and moving up and down with a jack device, and is used in a coastal area where the water depth is relatively shallow. On the other hand, the floating excavation ship is a floating ship or the like in which excavation equipment is disposed, and is used in a continental shelf or a deep sea having a deep water depth (for example, a depth of 100 m or more). This floating drilling vessel is expected to be able to extract oil and gas in the sea area that is difficult to cope with with the deck lifting device, for example, semi-submersible drilling rigs and ship-type drilling rigs are known .

However, floating excavation ships are oscillated by the movement of waves and tidal currents. Therefore, a structure that can dig stably with minimum oscillation is required. For this reason, structures such as bilge keels and anti-vibration tanks are adopted for floating excavators. For example, a semi-submersible type marine structure is known in which a plurality of space chambers having openings are formed in the vicinity of the water line, and a lid that can open and close an upper opening corresponding to each space chamber is provided. (For example, refer to Patent Document 1).
Also, offshore wind turbines that are not floating excavator structures but have a wind turbine connected via a shaft to a generator rotatably mounted on the tower and a float-shaped lower foundation with the tower attached Methods and apparatus related to the use of turbines are known (see, for example, Patent Document 2). The method and apparatus associated with the use of this offshore wind turbine draws energy from the wave by acting as a damping mechanism on the movement of the wind turbine as a wave effect on the float.

Japanese Patent Laid-Open No. 7-25382 Special table 2007-503548

  However, since the conventional semi-submersible type marine structure is reduced by using a space room, the effect is not sufficient for large fluctuations, for example. For this reason, development of the apparatus which suppresses rocking | swiveling more effectively is desired.

  The present invention has been made in view of such circumstances, and provides a vibration reducing device that more effectively suppresses rocking.

  According to the present invention, it is provided with a propeller that is rotated by wind power, a tower that rotatably supports the propeller, and a floating body that mounts the tower, and the floating body constitutes a floating excavation ship, and the rotation of the propeller A rocking device is provided that reduces rocking of the floating excavation ship.

  Generally, waves are generated by wind in the ocean. The vibration reducing device of the present invention suppresses the swinging of the floating body due to the waves by rotating the propeller with this wind. That is, in the vibration reduction device of the present invention, wind energy is converted into a damping force through the tower, and the swinging of the floating body is suppressed. For this reason, according to the structure of this invention, the vibration reduction apparatus which suppresses rocking | fluctuation of the floating excavation ship which comprises the said floating body more effectively is provided.

It is the side view and front view for demonstrating the structure of the vibration reduction apparatus which concerns on one Embodiment of this invention. It is a side view for demonstrating the effect | action of the vibration reduction apparatus which concerns on one Embodiment of this invention. It is a side view for demonstrating the structure of the semi-submersible type drilling rig which concerns on one Embodiment of this invention. It is a front view for demonstrating the structure of the semi-submersible type drilling rig which concerns on one Embodiment of this invention. It is a front view for demonstrating the modification of the semi-submersible type drilling rig which concerns on one Embodiment of this invention. It is a front view for demonstrating the other modification of the semi-submersible type drilling rig which concerns on one Embodiment of this invention. It is a side view for demonstrating the structure of the ship-type drilling rig which concerns on one Embodiment of this invention. It is a side view for demonstrating the modification of the hull form excavation rig which concerns on one Embodiment of this invention. It is a side view for demonstrating the demonstration experiment of this invention. It is a top view for demonstrating the demonstration experiment of this invention. It is a graph which shows the result of the demonstration experiment of this invention. It is a graph which shows the result of the demonstration experiment of this invention. It is a graph which shows the result of the demonstration experiment of this invention.

The vibration reduction device of the present invention includes a propeller that is rotated by wind power, a tower that rotatably supports the propeller, and a floating body that mounts the tower, and the floating body constitutes a floating excavation ship, According to the present invention, the swing of the floating excavation ship is reduced by rotation.
Here, the floating excavator is an excavator for excavating natural resources such as oil and gas floating on the ocean. For example, a semi-submersible excavation rig and a hull excavation rig correspond to this.
The floating excavation ship is configured by the platform and the floating body. However, the platform may be formed integrally with the floating body, and the platform may be fixed to the floating body via a support column.

In the embodiment of the present invention, the tower may also be used as a tower for holding and lowering the excavation formation. For example, it may be combined with a tower arranged on a well for excavation of a semi-submersible drill rig or a ship-type drill rig, and a tower arranged on the well for excavation and a second provided on the tower. May be configured with a tower.
Here, the excavation formation includes, for example, a drill or a riser pipe for excavating the seabed or lake bottom, and the tower is equipped with equipment for holding and lowering them underwater.

In another embodiment of the present invention, the tower may be provided at a peripheral portion of the floating excavation ship, the floating excavation ship includes a platform, and the tower is a floating excavation on the platform. It may be mounted at a position away from the center of gravity of the ship. In the vibration reduction device of the present invention, the greater the distance between the center point of the propeller and the center point of the floating body, the greater the effect of suppressing the swinging of the floating body. For example, since the floating body swings due to the relationship between buoyancy and the center of gravity, the center point on the waterline may be obtained by approximating the center of gravity and its position. According to such an approximate relationship, the tower may be mounted at a position away from the center of gravity of the floating excavation ship.
Specifically, for example, when the floating drilling vessel is a semi-submersible drilling rig, the semi-submersible drilling rig supports the platform, the hull floating in water, and the periphery of the platform at the upper end. A plurality of support columns having lower ends connected to the hull may be provided, and the tower may be disposed on the periphery.
Further, when the floating excavation ship is a hull excavation rig, the tower may be arranged at the bow or stern of the hull excavation rig.

In an embodiment of the present invention, for example, the distance between the propeller and the center point of the floating body is 90 m, and the diameter of the propeller is 120 m.
The vibration reduction device of the present invention may further include a generator connected to the propeller. When the propeller is rotated by wind power, it is possible to more effectively suppress the swinging of the floating excavation ship and to generate wind power. Since the floating excavator is prevented from swinging, stable power generation can be achieved. For example, the generated power may be used for excavation work.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. The embodiments and examples described below are merely specific examples of the present invention, and the present invention is not limited thereto.

[Embodiment 1]
FIG. 1 is a side view and a front view for explaining the configuration of a vibration reducing device according to an embodiment of the present invention. In FIG. 1, the left diagram is a side view of the vibration reduction device, and the right diagram is a front view of the vibration reduction device. As shown in FIG. 1, the vibration reduction device includes a windmill 1, a tower 2, and a floating body 3. This anti-vibration device is used suspended on the surface of the ocean, lake water or the like.

  The windmill 1 is composed of a plurality of windmill blades, and the center of rotation thereof is rotatably supported by a windmill nacelle 11 at the upper end of the tower 2. In the windmill 1, as will be described later, the relationship between the drag generated by the windmill and the center of the windmill and the floating body 3 is important. In the embodiment of the present invention, as long as this relationship is satisfied, the specific size and form (number of windmill blades, etc.) of the windmill 1 are not particularly limited. For example, the windmill 1 is comprised by three windmill blades, and the diameter is 120 m.

  For example, a windmill for wind power generation may be used as the windmill 1. Since it is a vibration reducing device, it is not necessary to provide a generator in particular. However, in addition to using the windmill 1 as a part of the vibration reducing device, it may be configured to perform wind power generation. That is, the windmill nacelle portion 11 may be provided with a generator, and the generator may be rotatably fixed to the rotation center portion of the windmill 1 through a shaft. Although the vibration reduction action is reduced, it is possible to extract wind energy from the rotation of the windmill.

  The windmill nacelle portion 11 is fixed in a direction that intersects the axial direction of the tower 2. In the case of the windmill nacelle portion 11 of this embodiment, the windmill nacelle portion 11 is fixed in a direction perpendicular to the axial direction of the tower 2. The intersecting direction may be adjusted according to the swing, and may be fixed so as to be adjustable by about 5 ° with respect to the axial direction of the tower 2, for example.

  The tower 2 rotatably supports the windmill nacelle portion 11 at one end and is fixed to the floating body 3 at the other end. In the case of this embodiment, since the floating body floats on the water surface in a form substantially parallel to the bottom surface, the tower 2 is arranged in a direction substantially perpendicular to the water line. The tower 2 only needs to play a role of separating the windmill nacelle portion 11 and the floating body 3 by a predetermined distance. Therefore, in addition to the configuration of one pillar shown in FIG. 1, for example, a plurality of pillars are combined like a tower. May be configured. Moreover, the windmill nacelle part 11 may be fixed to a pillar or a tower, and may be further provided with a support on the upper part.

The floating body 3 supports the windmill 1 via the tower 2 and floats in the ocean, for example. In this embodiment, although it is comprised with the cylindrical structure, since it should just be a structure which floats on liquids, such as seawater, the shape is not restricted to a column shape. For example, it may be a prismatic shape or a hull shape.
A platform 31 is provided on the upper surface of the floating body 3, and excavating equipment is mounted on the platform 31. The platform 31 and the floating body 3 constitute a floating excavation ship, and these configurations correspond to a semi-submersible excavation rig, a hull excavation rig, and the like.

  The platform 31 may be configured integrally with the floating body 3, and a part of the surface of the floating body 3 may correspond to the platform 31. For example, in the case of a semi-submersible drilling rig, the platform 31 and the floating body 3 May be connected by a support. That is, the platform 31 may be configured by a structure (for example, a plane body) different from the floating body 3.

  The floating body 3 is used by being connected to an anchor 4 installed on the sea bottom (lake bottom) via a cable. As a result, the floating body 3 is prevented from being washed away by an ocean current or the like.

  In this vibration reduction device, when the wind turbine 1 of the constituent element is rotated by the wind, the energy of the wind is converted into a damping force, and the swinging of the floating body is suppressed. Generally, waves are generated by wind in the ocean. For this reason, the rocking | fluctuation of the floating body by a wave can be reduced by the energy of the wind which generate | occur | produces a wave. Next, a mechanism for converting wind energy into damping force in the vibration reduction device according to this embodiment will be described. FIG. 2 is a side view for explaining the operation of the vibration reducing device according to this embodiment. In FIG. 2, the front view of the windmill 1 is shown at the upper left.

As shown in FIG. 2, the case where the floating body 3 is swung by a wave having a wave direction 150 and the wind flows into the windmill 1 at a flow velocity V (200 shown in FIG. 2; unit: m / s) will be described. It is assumed that the vertical pitch 21 of the platform on the upper surface of the floating body 3 is θ (rad), and the angle difference between the wave direction angle and the wind direction angle is χ (rad). Angular velocity is
Therefore, when the floating body 3 receives a wave and swings, the flow velocity of the air flowing into the surface of the windmill 1 is
It becomes. Here, l is a distance 20 (unit: m) from the center point 35 on the water line of the floating body 3 to the center of rotation of the windmill 1 (center of the windmill nacelle 11). Here, the draft line means not a draft line of the floating body 3 alone but a draft line in a state where the propeller 1 is provided on the floating body 3 via the tower 2.

At this time, the force in the horizontal direction (direction X in FIG. 2) generated in the windmill 3 is
It is. Here, C _D is the drag force by the windmill, ρ _A is the air density, and S is the windmill area 15 (S shown in FIG. 1).

If we expand the number 1,
It becomes. Pitch angular velocity
Term proportional to because means damping factor, if the attenuation coefficient of the pitch and B _theta, damping coefficient B _theta is expressed by the following equation 3.
From this number 3, the damping coefficient B _theta can understand to cause swinging motion reducing effect of the floating body 3 as a damping force. That is, it can be understood that when wind flows into the windmill 1, a damping force that reduces the swing of the floating body 3 is generated in the windmill 1.
FIG. 2 shows a case where the angle difference χ is 0 (rad).

[Embodiment 2]
Next, the form which concerns on a semi-submersible type drilling rig is demonstrated. FIG. 3 is a side view for explaining the configuration of the semi-submersible drilling rig according to the embodiment of the present invention. FIG. 4 is a front view for explaining the configuration of this semi-submersible drilling rig. FIG. 3 and FIG. 4 are diagrams showing the state of use of the semi-submersible drilling rig, and show the state where the semi-submersible drilling rig floats on the sea.
As shown in FIGS. 3 and 4, the semi-submersible drilling rig is similar to the first embodiment, in which the propeller 1, the excavation tower 20 corresponding to the tower 20, and the semi-submersible drilling rig corresponding to the floating body 3 are used. The main body 3 </ b> A constitutes a vibration reducing device as a whole. The semi-submersible drilling rig is known as an embodiment of a floating drilling ship, and is a rig used for oil and gas drilling in the ocean (for example, a continental shelf) with a depth of about 100 m or more.

  The propeller 1 is composed of three wind turbine blades as in the first embodiment, and its rotation center is rotatably supported by the wind turbine nacelle 11 and is fixed to the upper end of the excavation tower 2 via a shaft. Yes. Further, the shaft is rotatably fixed to the axis of the excavation tower 20 (an axis substantially parallel to the direction in which the riser pipe 51 extends in FIG. 1) by the rotation mechanism 12 provided on the upper part of the excavation tower 20. . The propeller 1 is turned by the rotating mechanism 12, and the propeller 1 faces the wind.

  Further, the excavation tower 20 is built in a direction perpendicular to the semi-submersible drilling rig body 3A on a well provided in the semi-submersible drilling rig body 3A. The excavation tower 20 is provided to extend and hold a riser pipe 51 (which may be a guideline) that is a drilling formation to the seabed, and the riser pipe 51 penetrates the semi-submersible drilling rig main body 3A. It extends downward from the excavation tower 20 through the well provided. For example, the excavation tower 20 has a height of 100 to 150 m from the upper surface of the semi-submersible excavation rig main body 3A (that is, the upper surface of the platform 31).

The semi-submersible drilling rig main body 3 </ b> A includes a platform 31, a plurality of columns (columns) 32, and a lower hull (lower hull) 33. The platform 31 is disposed on the upper surface of the semi-submersible excavation rig main body 3A, and is equipped with excavation equipment and a structure 50 for excavation. Moreover, the support | pillar 32 is arrange | positioned under the platform 31 and supports the periphery (for example, four corners, if a platform is a quadrilateral shape) by the upper end. In this embodiment, eight struts 32 support the platform 31. Further, the lower hull 33 is connected to the lower end of the support column 32 and functions as a buoyancy body that floats the platform 31 on the water surface (for example, the sea surface) via the support column 32.
Here, the platform 31 is a so-called work deck, and the lower hull 33 corresponds to a floating body.

  Further, the lower hull 33 in the semi-submersible drilling rig main body 3A is in a state of being submerged in the sea as shown in the use state of the semi-submersible drilling rig of FIGS. As described above, the semi-submersible drilling rig main body 3A has a structure in which the lower hull 33 can be submerged in the sea and the support column 32 can be submerged to the middle by introducing seawater into the main body. . Since the wave force decreases in the depth direction, the lower hull 33 of the semi-submersible drilling rig can be submerged in the sea, and the swing of the semi-submersible drilling rig can be reduced.

  The semi-submersible drilling rig main body 3A is connected to the anchor 4 via a wire in the support column 32 or the lower hull 33, and is moored on the seabed.

As described above, the rocking device in the form of a semi-submersible drilling rig includes the excavation tower 20. In this embodiment, as shown in FIG. 4, since the propeller 1 is disposed on the excavation tower 20, the center point 35 in the vicinity of the draft line of the semi-submersible drilling rig main body 3 </ b> A and the rotation center portion of the propeller 1. The distance l is large. As a specific example, when the height of the excavation tower 20 is 100 to 150 m and the distance from the vicinity of the water line to the upper surface of the platform 31 is 20 to 40 m, the distance l is 120 to 190 m.
Here, the waterline is a waterline when the semi-submersible drilling rig is used, that is, a semi-submersible excavation in which the drilling equipment and the structure 50 for excavation are mounted on the platform 31 and the lower hull 33 is submerged in the sea. It is a water line in the use state of a rig.

  As described above, the semi-submersible drilling rig according to this embodiment includes the excavation tower 20 to form a vibration reduction device, and the propeller 1 is disposed on the excavation tower 20, so that a new tower is installed. The distance l can be increased without providing it. For this reason, the damping coefficient Bθ takes a large value in the vibration reduction device constituted by the propeller 1, the excavation tower 20, and the semi-submersible excavation rig main body 3A. Therefore, the vibration reduction device provided with the excavation tower 20 can generate a large damping force and greatly reduce the swing of the semi-submersible excavation rig. In addition, since the swing of the semi-submersible drilling rig is greatly reduced, the swing of the tower 2 is also reduced, and fatigue failure of the tower 2 can be prevented. For this reason, the years of operation and safety of the vibration reduction device and the excavation equipment can be improved.

  Also in this vibration reduction device, a generator connected to the propeller 1 may be provided as in the first embodiment, and wind power generation may be performed with this vibration reduction device. For example, the rotation center part of the propeller 1 may be rotatably connected to the generator, and the generator may be disposed in the windmill nacelle part 11, or the shaft connected to the propeller 1 may be rotatably connected to the generator. Also good. With such a configuration, not only can the propeller 1 be rotated by wind power to suppress the swinging of the floating excavation ship, but also power can be generated by this vibration reduction device. Further, the direction of the propeller 1 is stabilized and the rotation thereof is stabilized. In general, it is said that the swing of the propeller 1 does not have a large effect on the power generation amount, but the swing of the tower 2 becomes small, so that the operational years and safety of the vibration reducing device constituting the wind power generator are reduced. Can be improved.

[Modification of tower]
In this embodiment, the propeller 1 is disposed on the excavation tower 20, but the propeller 1 may be disposed on the peripheral portion of the semi-submersible drilling rig in consideration of the size of the semi-submersible drilling rig. . That is, the semi-submersible drilling rig generally has a length of 100 to 160 m and a width of 50 to 100 m. Therefore, the propeller 1 is arranged at the peripheral edge of the semi-submersible drilling rig, and the semi-submersible drilling rig main body 3A. The distance l between the center point 35 in the vicinity of the water line and the rotation center of the propeller 1 can be increased. In the case of the above-described general semi-submersible drilling rig, for example, the distance between the center point 35 near the water line of the semi-submersible drilling rig main body 3A and the peripheral edge of the semi-submersible drilling rig (for example, each column at four corners) is 25. The distance l can be made sufficiently large. Therefore, the swing of the semi-submersible excavation rig can be attenuated without providing a relatively large tower such as the excavation tower 20 or the tower shown in the first embodiment.

  5 and 6 show a modification of the semi-submersible drilling rig according to the second embodiment. FIG. 5 is a front view for explaining a modification of the semi-submersible excavation rig according to the embodiment of the present invention. FIG. 6 is a front view for explaining another modified example of the semi-submersible excavation rig. These figures, like FIGS. 3 and 4, are diagrams showing the state of use of the semi-submersible drilling rig, and show a state where the semi-submersible drilling rig is floating on the sea.

  As shown in FIG. 5, this semi-submersible drilling rig includes a tower 2A formed on an extension line of a column 32A arranged at a corner of the semi-submersible drilling rig, and the propeller 1 is mounted on the tower 2A. Has been placed. Further, the support column 32 </ b> A supports the peripheral portion of the platform 31 (or the excavation structure 50 disposed on the peripheral portion) at one end, and the other end is connected to the lower hull 33. The structure of the wind turbine nacelle part, the rotation mechanism 12 and the shaft of the propeller 1 is the same as that of the second embodiment.

The pillars 32A on which the tower 2A is disposed are one of the pillars disposed at the four corners of the semi-submersible drilling rig, and are located in the periphery of the semi-submersible drilling rig. The center point 35 is arranged apart from the center point 35, and the distance is large. Therefore, the distance l between the center point 35 in the vicinity of the draft line of the semi-submersible type drilling rig main body 3A and the rotation center portion of the propeller 1 can be increased. For this reason, the damping device according to this modification generates a large damping force that suppresses the swing, and the swing of the semi-submersible excavation rig can be significantly reduced.
In addition, in this modification, although the semi-submersible excavation rig provided with the eight support | pillars 32 is demonstrated, the number of support | pillars is not restricted to this, For example, four may be sufficient. Moreover, although it demonstrated by one of the support | pillars arrange | positioned at four corners, if it is a support | pillar which supports the peripheral part of the platform 31, it will not be restricted especially in four corners.

  Further, as shown in FIG. 6, in another modification of the semi-submersible drilling rig, a support column 32B arranged at a corner of the semi-submersible drilling rig is arranged to extend above the platform 31, The propeller 1 is disposed via the support rod 12A disposed on the support column 32B. The structure of the wind turbine nacelle and shaft of the propeller 1 and the connection relationship between the support column 32 and the lower hull 33 are the same as in the second embodiment.

  The strut 32B is also one of the struts arranged at the four corners of the semi-submersible drilling rig, like the strut 32A, but extends upward from the upper surface of the platform 31, and is provided with a support bar 12A at its end. Yes. That is, the support column 32B penetrates the peripheral portion of the platform 31 in the vicinity of the upper portion thereof, and supports the platform 31 by the penetration portion, and the support bar 12A is provided at the upper end thereof in the extending direction. The lower hull 33 is connected to the lower end. Here, the support bar 12A is a support bar that supports the propeller 1, and includes a rotation mechanism that supports the shaft of the propeller 1 so as to be rotatable with respect to the axis of the support column 32B.

  Since this support | pillar 32B is also in the peripheral part of a semi-submersible type drilling rig, it is arrange | positioned away from the center point 35 of the semi-submersible type drilling rig main body 3A vicinity of the waterline, and the distance is large. For this reason, the distance l can be made large similarly to the said modification. Therefore, a large damping force that suppresses the swing is also generated in the vibration reduction device according to the modification including the support column 32B, and the swing of the semi-submersible excavation rig can be significantly reduced.

  In these modifications of the semi-submersible drilling rig, the propeller 1 is disposed on the support column 32 via the tower 2A and the support rod 12A. However, the propeller 1 is connected to the support column 32 or the platform 31 via a shaft and a rotation mechanism. It may be arranged. In this case, since the tip of the propeller 1 reaches below the platform 31 and rotates, the propeller 1 is substantially parallel to the outer periphery of the platform 31 by limiting the rotation angle of the rotation mechanism. Configure.

[Embodiment 3]
Next, the form which concerns on a hull form excavation rig is demonstrated. FIG. 7 is a side view for explaining the configuration of a hull excavation rig according to an embodiment of the present invention. This figure is a figure which shows the use condition of a hull type excavation rig similarly to Embodiment 1 and 2, and has shown a mode that the hull type excavation rig has floated on the sea.
As shown in FIG. 7, as in the first and second embodiments, the boat-type drilling rig includes a propeller 1, a drilling tower 20 corresponding to the tower 2, and a boat-type drilling rig corresponding to the floating body 3 or the semi-submersible drilling rig. 3B, and constitutes a vibration reduction device as a whole. Similar to the semi-submersible drilling rig, the hull-type drilling rig is known as an embodiment of a floating drilling ship, and is a rig used for exploration and drilling of resources such as oil and gas in the ocean with a deep water depth of about 1500 m or more.

  The ship-type drilling rig 3B is a ship on which drilling equipment and the like are arranged, and a drill shaft for excavation and a well for extending the riser pipe 51 into the sea are arranged. In this embodiment, as shown in FIG. 7, the excavation tower 20 is disposed on the well, and the propeller 1 is disposed on the excavation tower 20 as in the second embodiment.

Also in this embodiment, similarly to the second embodiment, the boat-type excavation rig includes the excavation tower 20 to constitute a vibration reduction device, and the propeller 1 is disposed on the excavation tower 20. For this reason, the distance l between the center point 35 in the vicinity of the water line of the hull-type excavation rig 3B and the rotation center of the propeller 1 can be increased without providing a new tower. Therefore, similarly to the second embodiment, the damping coefficient Bθ takes a large value also in the vibration reduction device of this embodiment. As described above, the damping device of this embodiment also generates a large damping force that suppresses the swing, and can greatly reduce the swing of the boat-type excavation rig.
In general, a hull-type drilling rig has a single hull and a structure similar to that of a general ship. The hull digging rig according to this embodiment includes the excavation tower 20 to constitute a vibration reduction device, and suppresses the fluctuation of the hull digging rig as described above. It is effective.

Next, a modified example of the hull excavation rig according to the embodiment will be described. FIG. 8 is a side view for explaining a modification of the hull excavation rig according to the third embodiment.
As shown in FIG. 8, the hull digging rig according to this modification is composed of a propeller 1, a tower 2, and a hull digging rig 3 </ b> B, but not on the excavation tower 20 unlike the third embodiment. A propeller 1 is arranged on a tower 2 provided at the stern.

Also in this modified example, like the modified example of the second embodiment, it is arranged on the tower 2 by paying attention to the size of the hull digging rig 3B. Specifically, in this modification, the propeller 1 is disposed on the stern tower 2 that is the peripheral portion of the hull digging rig 3B. That is, since the length of the hull digging rig 3B is generally 100 to 250 m and the width is 20 to 40 m, the position away from the center point 35 in the vicinity of the waterline of the hull digging rig 3B in consideration of this length. A tower 2 is provided at the stern at, and a propeller 1 is disposed on the top. In the case of this modification, the distance l between the center point 35 in the vicinity of the water line of the boat-type excavation rig 3B and the rotation center of the propeller 1 is, for example, 60 to 100 m. Thus, by disposing the propeller 1 on the tower 2 provided at the stern of the hull digging rig 3B, the distance l between the center point 35 near the waterline of the hull digging rig 3B and the rotation center of the propeller 1 is increased. can do. For this reason, it is not necessary to provide a relatively large tower like the excavation tower 20 shown in the second embodiment. According to this modification, the swing of the semi-submersible excavation rig can be attenuated even with a relatively small tower.
In this modified example, the tower 2 is provided at the stern. However, even if a tower is provided at the bow, the same effect is obtained in terms of the vibration reduction effect.

Next, a verification experiment according to the embodiment of the present invention will be described. 9 and 10 are a side view and a top view of the demonstration experiment according to the embodiment of the present invention. In FIG. 9, the front view of the windmill is shown in the center, and the top view of the floating body is shown in the lower right.
As shown in FIG. 9, in this demonstration experiment, a 1/100 scale model of a vibration reduction device (actual machine) was used. Table 1 shows the values of parameters such as the total height in the floating body (floating body model) of this model and the values of the parameters of the actual machine corresponding to this.

The total height in Table 1 is the total height of E and G in FIG. 9, and GM in Table 1 corresponds to E in FIG. Here, the values of E to G in FIG. 9 are 100, 300, and 340 mm, respectively. The value I in FIG. 9 is 130 mm.

  Moreover, as shown in FIG. 9, since the floating body (floating body model) of this model is an initial design, GM100mm was set as a reference value. Further, the initial tension was assumed to be 1500 tonf in the actual machine, but in the model, it was 1.0 kgf, which is about 2/3 of the designed value.

  Table 2 shows the values of parameters such as the total height of the windmill (windmill model) of this model and the values of the corresponding actual machine parameters.

The total height in Table 2 is the total height of A and D in FIG. Here, each value of A to D in FIG. 9 is 1200, 800, 1500, and 180 mm, respectively.

  This model windmill (windmill model) was designed assuming a 5MW scale large horizontal axis propeller windmill of wind power generation as an actual machine. The wind turbine blades were made of PS foam and CFRP.

  Experimental conditions were set with reference to statistical data for all seasons in the North Pacific. Table 3 shows the conditions of waves and wind speed. The wave height was set to 1/100 according to the scale-down ratio and the wave period was set to 1/10 according to the field rule from the conditions of the sea area where the actual machine is assumed to be placed. The wind speed was calculated and determined by the blade element theory and the momentum theory so that the horizontal wind drag generated in the windmill coincided.

In this demonstration experiment, in addition to the wind and wave coexistence field experiment, a wind alone experiment and a wave alone experiment were also conducted. In the wind / wave coexistence field experiment, wind and waves were generated from the front of the floating model and the windmill model using the blower 300 and the wave generator 310 (FIG. 10).
Such an experiment was conducted using the experimental equipment shown in FIG. The movement of the model (pitching, surging, and heaving) was measured by tracking the displacement of the LED sensors 301 and 302 (installed at the windmill nacelle and tower 2 base) shown in FIG. 9 with the CCD camera 306 shown in FIG. Further, the wind drag force generated in the model windmill was calculated by measuring the bending moment using a strain gauge 303 (installed at the base of the tower 2) shown in FIG. The tension generated in the mooring line was measured using the ring gauge 304 of FIG.
In FIG. 10, the floating body (floating body model) 3 is arranged such that the distance J from the CCD camera 306 is 2500 mm and the distance K from the wave generator 310 is 2150 mm. In FIGS. 9 and 10, a floating body lower portion 36 including three legs projecting laterally from the floating body is provided, and two anchor 4 anchoring portions are provided on each leg. As shown in FIG. 9, a ring gauge is provided between 304A, 304C, 304E and the anchor 4 (no ring gauge is provided between 304B, 304D, 304F and the anchor 4).

FIGS. 11 to 13 show the results of the demonstration experiment. FIG. 11 is a graph showing the primary pitching amplitude of the model in the wind / wave coexistence field experiment and the wave alone experiment. FIG. 12 is a graph showing the bending moment amplitude in the same wind / wave coexistence field experiment and wave single experiment as in FIG. FIG. 13 is a graph showing the FFT analysis result of the tension generated on the mooring line of the floating body model during synchronization in the wind / wave coexistence field experiment and the wave alone experiment.
Each point in FIGS. 11 to 13 corresponds to each condition in the wind / wave coexistence field experiment or the wave single experiment.
Each condition of FIGS. 11 and 12 is as follows: (1) Regular, wave height 2.0 cm, wind speed 1.32 m / s, (2) Middle, wave height 4.0 cm, wind speed 1.67 m / S, (3) is cut-out, wave height is 6.0 cm, wind speed is 2.15 m / s, (4) is regular, wave height is 2.0 cm, and (5) is middle. ), Wave height 4.0 cm, (6) is cut-out, wave height 6.0 cm.
Each condition in FIG. 13 is that (1) has a wave period of 0.9 seconds and a wave height of 6.0 cm and a wind speed of 2.17 m / s, and (2) has a wave period of 0.9 seconds and a wave height of 6.0 cm.
Here, (1) to (3) in FIGS. 11 and 12 correspond to an embodiment of the present invention, and (4) to (6) correspond to a conventional floating body (a state where no propeller is disposed). ing. Further, (1) in FIG. 13 corresponds to an embodiment of the present invention, and (2) corresponds to a conventional floating body (a state where no propeller is disposed).
11 and 12 (4) to (6) and FIG. 13 (2) reproduce the state of the conventional floating body by fixing the rotating shaft of the windmill of the windmill model.

Referring to FIG. 11, in any wind / wave coexistence field experiment of (1) to (3), the primary pitching amplitude changes at about 1 to 2 degrees, and the wave alone experiment of (4) to (6). As can be seen from FIG.
From this result, it can be understood that the device constituted by the windmill, the tower, and the floating body has an effect of suppressing the swinging of the floating body. It can also be understood that the pitching motion causing fatigue failure is reduced, so that the life of the device is extended and the safety is improved.

Referring to FIG. 12, as in FIG. 11, the bending moment amplitude of any wind / wave coexistence field experiment of (1) to (3) is higher than that of the wave alone experiment (4) to (6). It can be seen that there is a significant decrease. This is thought to be because pitching motion decreased due to wind drag.
Since the bending moment amplitude generated at the base of the tower 2 is reduced, it can be understood that the life of the device is extended and the safety is improved as in FIG.

Referring to FIG. 13, in the wind / wave coexistence field experiment of (1), the steady cord tension is increased, but the amplitude is greatly reduced compared to the wave alone experiment of (2). ing. In addition, the amplitude that causes the spiking response of the double period and the triple period also decreases.
Also from this result, it can be understood that the device composed of the windmill, the tower, and the floating body has an effect of suppressing the swinging of the floating body.

  From the above demonstration experiment, it can be seen that the vibration reduction device including the windmill, the tower, and the floating body suppresses the swinging of the floating body due to the waves when the windmill rotates with the wind. According to such a configuration, it is possible to provide a vibration reducing device that suppresses the swinging of the floating body.

  Various features shown in the above embodiments can be combined with each other. In the case where a plurality of features are included in one embodiment, one or a plurality of features can be appropriately extracted and used alone or in combination in the present invention. Single or combined configurations are also included in the technical scope of the present invention. For example, it goes without saying that a configuration in which the vibration reduction device applied to the boat-type drilling rig further includes a generator may be adopted.

1 Windmill (propeller)
2 2A 2B Tower 3 Floating body 4 Anchor 3A Semi-submersible drilling rig 3B Ship-type drilling rig 11 Windmill nacelle part 12 Rotating mechanism 15 Windmill area (S)
20 Distance from the center point 35 near the water line to the center of rotation of the windmill 1 (l)
21 Pitch of the platform on the upper surface of the floating body 3 (θ)
31 platform (floating body upper surface)
32 32A 32B Prop 33 Lower hull 35 Center point in the vicinity of the draft line 36 Floating lower part 50 Drilling equipment and structure 51 for drilling Riser pipe 100 Water surface 150 Wave direction 200 Wind direction 300 Air blower 301, 302 LED sensor 303 Strain gauge 304 Ring gauge 305 Wave height Total 306 CCD camera 307 Measuring device 308 Wave quenching device 309 Towing cart 310 Wave making device

Claims (9)

A propeller that rotates by wind power,
A tower that rotatably supports the propeller;
A floating body on which the tower is mounted,
An anti-vibration apparatus characterized in that the floating body constitutes a floating excavation ship, and the swing of the floating excavation ship is reduced by rotation of the propeller. The vibration reduction device according to claim 1, wherein the tower is also used as a tower for holding and lowering the excavation formation. The floating drilling vessel comprises a platform;
2. The vibration reducing device according to claim 1, wherein the tower is mounted on the platform at a position away from the center of gravity of the floating excavation ship. The vibration reduction device according to any one of claims 1 to 3, wherein the floating excavation ship is a semi-submersible excavation rig. The floating drilling vessel is a semi-submersible drilling rig;
The semi-submersible drilling rig includes a platform, a hull that floats in water, and a plurality of struts that support the peripheral edge of the platform at the upper end and are connected to the hull at the lower end.
The vibration reduction device according to claim 3, wherein the tower is disposed on the peripheral edge. The vibration reduction device according to any one of claims 1 to 3, wherein the floating excavation ship is a hull excavation rig. The floating drilling vessel is a hull drilling rig;
The vibration reduction device according to claim 3, wherein the tower is disposed at a bow or stern of a hull digging rig. The distance between the center point of the propeller and the center point on the waterline of the floating excavator is 90 m,
2. The vibration reducing device according to claim 1, wherein the propeller has a diameter of 120 m. Furthermore, the vibration reduction apparatus as described in any one of Claims 1-8 provided with the generator connected to the said propeller.