JP2010234965A - Tension mooring floating body system, support system, and floating body towing method and installation method using this support system - Google Patents

Abstract

A submerged part and a submerged area of a floating body for supporting an upper structure can be reduced, and further, an upper mooring part of a tension mooring line is maintained on the water surface, and a tension mooring line is attached. Provided is a tension mooring floating body system that can avoid underwater work such as tension adjustment work and maintenance inspection work.
In a tension mooring floating system 1, a floating body 12 for supporting the weight of an upper structure 11 on a water surface by buoyancy, a central columnar body 12a, a submerged buoyant body 12b, and a central columnar body 12a. A water surface coupling body 12c extending in the peripheral direction from the water surface and a water surface mooring part 12d which is disposed at an end of the water surface coupling body 12c and to which the upper end of the tension mooring line 13 is fixed; All or half or more of the surface area of the water surface connector 12c is above the water surface during still water, and the water mooring portion 12d is above the water surface during still water.
[Selection] Figure 1

Description

  INDUSTRIAL APPLICABILITY The present invention can support at least one of a tension mooring floating body system in which a tension mooring floating body used as a pedestal of a wind power generator or the like is tension moored, and a towing operation, an installation operation, a maintenance inspection operation, and a removal operation of the floating body. The present invention relates to a support system, and a floating body towing method and installation method using the support system.

  Regarding wind power generation, a proposal has been made to install a tension mooring floating body (TLP: tension leg platform) in a relatively deep water area on the coastal continental shelf, and to mount a device such as a wind power generator on the tension mooring floating body. I'm starting. For example, as shown in FIG. 9, the floating body 12 on which the pedestal 11 of this wind power generator is mounted includes one or more (four in FIG. 9) tension mooring lines 13 called tendons attached to the floating body 12. And anchored to a fixing subsidence member 14 such as an anchor provided on the bottom 2 of the seabed, lake, river, or the like.

In general, the tension mooring floating body 1X as shown in FIG. 9 is not limited to the wind power generator, and the ballast water is poured into the ballast tank of the floating body 12 or the ballast is loaded, so that the draft of the floating body 12 is drawn. In a state where it is deepened and submerged than in the installation state, it moves onto the fixed bottom member 14 installed in the preset water area in advance. After the movement, the upper end of the tension mooring line 13 is connected to the upper mooring part 15c of the floating body 12.
And the lower end of the tension mooring line 13 is joined to the lower mooring part 14c of the fixing settling member 14.

  After joining, the buoyancy of the floating body 12 is set to a preset buoyancy by discharging the ballast water or removing the ballast while paying attention to the inclination of the floating body 12 on which the upper structure 11 is mounted. Furthermore, the length of the tension mooring lines 13 is changed to adjust the inclination of the upper structure 11 and the magnitudes of the tensions T1 to T4 of the tension mooring lines 13. In this installation, the tension mooring line 13 is set in advance so that the tension mooring floating body 1X does not shake up and down, laterally tilt, and vertically tilt in the waves, and the movable range within the horizontal direction falls within the allowable range. The applied initial tensions T1 to T4 are applied and moored (see, for example, Patent Documents 1 and 2).

  Further, in the case of mounting a wind power generator that does not require a large area for mounting the superstructure, a columnar body (center column) 12a penetrating the water surface as shown in FIG. 10, and this columnar body An upper end side of a plurality of tension mooring lines 13 is fixed to a floating body 12 having a submerged buoyancy body (pontoon) 12b connected to the lower part of 12a, and a lower end side of the tension mooring lines 13 is fixed to the bottom 2 It has been proposed that the tension mooring cable 13 is connected to the lower anchoring portion 14c of the bottom sinking member 14 and tension is applied to the tension mooring cable 13 to hold the tension mooring floating body 1Y in position (see, for example, Patent Documents 3 and 4). .

  In a tension mooring floating body 1Y called a “mini tension leg platform (mini TLP)” composed of a floating body 12 having a columnar body 12a penetrating the water surface and a submerged buoyant body 12b connected to the columnar body 12a, The tension mooring line 13 is moored to the upper mooring part 15c of the submerged buoyancy body 12b at the water depth D. Since the tension mooring floating body 1Y has only the columnar body 12a penetrating the water surface after installation, the influence on the tension of the tension mooring line 13 due to fluctuations in the tide level and up and down of the water surface due to waves is reduced.

  However, in the tension mooring floating body 1 </ b> X as shown in FIG. 9, there are submerged portions such as a lower portion 12 b of the floating body 12 for fixing the upper end of the tension mooring line 13 and a columnar body (column) 12 a that supports the base 11. Very big. Moreover, in the tension mooring floating body 1Y as shown in FIG. 10, the submerged portions such as the submerged buoyancy body 12b and the columnar body 12a below the floating body 12 for fixing the upper end of the tension mooring line 13 are very large. For this reason, the submerged area is large and spreads over a wide range, so the water-resistant paint surface in this submerged area becomes wider, and the amount of paint work and paint increases, and the secular change after tension mooring As a result, there is a problem that the maintenance area becomes large and the amount of work for maintenance management increases. Moreover, since the submerged area is large, there is a high possibility that the weight of the steel material will increase.

  In the “mini TLP” of the prior art, since the upper mooring portion 15c of the tension mooring line 13 is in the water, the work for attaching the tension mooring line 13, the tension adjustment work, the maintenance check work, and the like are work in the water. For this reason, the workability is poor and the work time is long, so the cost for these work increases. In addition, when the lower mooring part sinks unequally due to an earthquake or the like after installation, it is necessary to adjust the length of the tension mooring line 13 with respect to this unequal subsidence. Since it is submerged, there is a problem that it is necessary to work underwater.

  Furthermore, when the tension mooring floating body 1Y is not towed or installed when the tension mooring floating body 1Y is installed, the static restoring force is remarkably small because the portion penetrating the water surface is only the columnar body 12a. There is a problem that the stability performance of the floating body is very bad. Therefore, the use of a crane is indispensable for maintaining the posture of the tension mooring floating body 1Y during towing and installation.

  In this case, even a “mini-TLP” equipped with a wind power generator has a large power generation capacity and can exceed 1000 tons in weight, so the crane to be used must be a large offshore crane. This large offshore crane has a small number of ships in the market and is necessary from the time of towing until the completion of installation, so that the period of use of the large offshore crane becomes long. Therefore, it is difficult to adjust the schedule of towing and installation work, and there is a problem that costs increase.

Japanese Patent Laid-Open No. 1-145292 Japanese Patent Laid-Open No. 4-197887 Japanese Utility Model Publication No. 64-2692 JP 2005-69025 A

  The present invention has been made in view of the above-described situation, and the object of the present invention is to provide a submerged buoyant body for supporting a superstructure, simply for generating buoyancy without considering the restoring force against the inclination of the floating body. It can be made into a shape that is not easily affected by waves, the submerged area can be reduced, and the upper mooring part of the tension mooring line is maintained on the water surface, and the tension mooring line is attached. An object of the present invention is to provide a tension mooring floating body system that can avoid underwater work such as work, tension adjustment work, and maintenance inspection work.

  Another object of the present invention is to provide temporary support when performing at least one of a towing operation, an installation operation, a maintenance inspection operation, and a removal operation of the floating body of the tension mooring floating body system of the present invention. An object of the present invention is to provide a support system that can sufficiently support operations such as towing and installation of a tension mooring floating body, and a floating body towing method and installation method using the support system.

  A tension mooring floating body system for achieving the above object includes a floating body for supporting an upper structure, a plurality of tension mooring lines for mooring the floating body, and fixing the tension mooring lines to the bottom of the water. In the tension mooring floating body system configured to include a fixed bottom member, a center for supporting the floating body above the water surface by supporting the weight of the upper structure with buoyancy. A columnar body, a submerged buoyancy body provided at the lower part of the central columnar body, a water surface coupling body arranged radially extending from the central columnar body in the circumferential direction, and an end portion of the water surface coupling body The upper end of the tension mooring line is fixed, and has a mooring portion on the water surface, and all or half or more of the surface area of the coupling body on the water surface is above the water surface at the time of still water, The mooring part is above the surface of the water when it is still Configured to.

  According to this tension mooring floating body system, an upper structure for mounting various devices and equipment such as wind power generators, or an upper structure composed of various devices and equipment, is set at a predetermined height on the water surface. The submerged buoyant body provided on the lower side of the floating body to be supported can be simply a buoyant body for generating buoyancy without considering the restoring force, and the submerged area can be reduced. Moreover, it can be made into the shape which is hard to receive the influence by a wave. For example, the influence of the wave can be reduced by forming the upper part of the submerged buoyant body in a truncated cone shape, the intermediate part in a cylindrical shape, and the lower part in an inverted truncated cone shape.

  In addition, a mooring section on the water surface mooring the upper end of a tension mooring line that generates restoring force during mooring, and all or part of the on-water coupling body that connects the mooring section on the water surface and the central columnar body, Since it is configured to be arranged on the top, the submerged portion becomes very small.

  As a result, the submerged area is reduced, and most of the surface is the surface of the submerged buoyancy body, which is a very narrow range. Therefore, the surface to be coated with a special paint having water resistance and corrosion resistance in the submerged area is reduced. The amount of special paint and the amount of painting work can be reduced. In addition, in maintenance management for secular change after tension mooring, the area that requires underwater work is reduced, so the amount of work for maintenance management is reduced. Moreover, since the submerged area is small, the steel material weight can also be reduced.

  In addition, since the mooring section on the water surface is configured so as not to be submerged above the water surface during still water, the upper mooring section that fixes the upper end of the tension mooring line can be maintained on the water surface, The mooring line installation work, tension adjustment work, maintenance inspection work, etc. can be carried out in the air instead of underwater work. Therefore, workability is improved and work time is shortened, so that the cost for these work can be reduced.

  In addition, when the lower mooring part sinks unequally due to an earthquake or the like after the floating body is installed, it is necessary to adjust the length of the tension mooring line with respect to this unequal subsidence. Since it is on the surface of the water, it is not necessary to work underwater, and the adjustment work can be performed efficiently.

  However, on the other hand, since the tension mooring floating body system does not consider the restoring force of the submerged buoyancy body, in a situation where the tension mooring is not moored, the tension mooring floating body system is in an unstable state that easily falls.

  Therefore, a support system for achieving the above object is provided to support at least one of the towing operation, the installation operation, the maintenance inspection operation, and the removal operation of the floating body of the tension mooring floating system. A support floating body that is temporarily fixed to the mooring portion on the water surface.

  The support floating body is temporarily fixed to a mooring portion on the surface of the floating body for operations such as towing and installation. The support floating body can suppress the inclination of the mooring portion on the surface of the water and can secure the restoring force against the inclination of the floating body, so that the posture of the floating body can be stabilized. In other words, the heel (lateral inclination) and trim (vertical inclination) of the floating body can be suppressed by the support floating body.

  With this support floating body, the restoring force regarding the inclination of the floating body with respect to the water surface can be remarkably increased, so that the posture of the floating body can be stabilized and toppling can be prevented in operations such as towing and installation of the floating body. As a result, operations such as towing and installation of the floating body can be sufficiently supported, and support by a large offshore crane can be eliminated.

  In addition, since the support floating body is removed from the floating body after the tension mooring, the support floating body can be repeatedly used when a large number of floating bodies of the tension mooring floating body system are installed. As a result, it is possible to reduce the cost of operations such as towing, installation, maintenance inspection, and removal of one floating body.

  In the above support system, the support floating body is configured to have a buoyancy greater than its own weight and a restoring force against the inclination of the float. Since the support floating body has a buoyancy greater than its own weight, it can be part of the buoyancy that causes the floating body to float during towing, and the work for removing the support floating body from the mooring portion on the water surface can be easily performed.

  Further, it is possible to easily provide the restoring force with respect to the inclination of the floating body by increasing the area of the water penetration portion of the supporting floating body to some extent and causing the buoyancy change due to the fluctuation of the water level. Since there is a distance between the support floating body and the central columnar body of the floating body and a relatively large moment lever is provided, it is possible to easily control to suppress the inclination of the floating body. It is preferable that the support floating body is provided with a ballast tank so that the buoyancy can be adjusted in order to have a role of buoyancy adjustment during operations such as towing and installation.

  In the above support system, a winding system of a tension mooring line for tension mooring the floating body, a temporary mooring system for temporarily mooring the support floating body, a system for adjusting the ballast of the floating body, and a support floating body A system for ballast adjustment, a power supply system for the mooring unit on the water surface, a power supply system for the support floating body, at least one of the power supply system for the floating body, or a work support system composed of some combination, It is configured in preparation for the support floating body.

  According to this configuration, the support floating body includes a part or all of the incidental facilities used on the floating body side only during operations such as towing, installation, maintenance, and removal, so that these operations can be sufficiently supported. Thereby, a part or all of the incidental facilities of the floating body can be omitted, and the cost of the entire tension mooring floating body system can be reduced.

  In the above support system, the support floating body has a recess into which the water surface mooring part enters, and is joined to the water surface mooring part when the work is supported, and after the work support ends. Is configured such that the support floating body is separated from the mooring portion on the water surface.

  According to this configuration, since the support floating body has the recessed portion into which the water mooring part enters, the support floating body has many portions along the water mooring part, and the support floating body is difficult to come off from the water mooring part. In addition, the inclination of the mooring portion on the water surface can be easily suppressed, and the restoring force of the floating body can be reinforced more efficiently.

  Further, when the support floating body is joined to the floating body, if the concave portion is configured to be surrounded from the outside of the mooring portion on the water surface, the workability of the integrated work is improved as compared with the case where the concave portion is configured to be surrounded from the inside of the mooring portion on the water surface. Will be better. On the other hand, when the concave portion is configured to be surrounded from the inner side, the occupied area in the horizontal plane of the support floating body can be made smaller than when the concave portion is configured to be surrounded from the outer side. And tow on narrow routes. Thereby, the support floating body can be arranged with a small amount of work, and work such as towing and installation of the floating body can be sufficiently supported.

  In addition, a floating body towing method for achieving the above-described object is characterized in that the floating body is towed in the state where the support system is used when the floating body is towed.

  According to this towing method, when the floating body is towed, the support floating body is towed in a state of being temporarily fixed to the floating body, so that the inclination of the mooring portion on the surface of the water can be suppressed by this support floating body, and the restoring force against the inclination of the floating body Can be secured and the posture of the floating body can be stabilized. As a result, when the floating body is towed, the posture of the floating body can be stabilized and the fall can be prevented, so that support by a large offshore crane can be made unnecessary. Thereby, the towing operation | work of a floating body can fully be supported.

  Moreover, the installation method of the floating body for achieving said objective is a method characterized by using said support system in installation of the said floating body of said tension | moorage mooring floating body system.

  According to this installation method, since the installation work is performed in a state of being temporarily fixed at the time of installation of the floating body, the support floating body can suppress the inclination of the mooring portion on the water surface and ensure the restoring force against the inclination of the floating body. Installation work can be performed in a state where the posture of the floating body is stabilized.

  As a result, during the installation work of the floating body, the support of the large offshore crane for stabilizing the posture of the floating body and preventing overturning can be made unnecessary. Thereby, the installation work of a floating body can fully be supported. Further, since the support floating body can be used as a work table, the work area in the mooring section on the water surface can be reduced.

  In the above floating body installation method, the support floating body is formed with a temporary mooring system for temporarily mooring the floating body, and when the floating body is installed by the temporary mooring system, The fixing mooring line is moored by the tension mooring line after the supporting floating body is temporarily moored by lowering the fixing bottom member to which the lower end of the tension mooring line is moored by a temporary mooring system. After mooring with a rope, the temporary mooring is released.

  According to this method, the temporary mooring of the support floating body is performed under the effect of preventing the fall by the support floating body, so that the temporary floating can be easily moored without fear of falling, and further, the temporary floating provided on the support floating body side. Since the anchoring system lowers the anchoring subsidence member such as an anchor while supporting the weight thereof, a facility such as a winch for lowering the anchoring subsidence member to the water bottom on the floating body side or the work ship side becomes unnecessary.

  According to the tension moored floating body system of the present invention, the submerged buoyant body in the lower part of the floating body for supporting the upper structure at a predetermined height on the water surface is simply a buoyant body for generating buoyancy without considering the restoring force. Therefore, the shape can be made less susceptible to the influence of waves.

  In addition, since the submerged portion and the submerged area are reduced, it is possible to reduce the coating surface of the water-resistant and corrosion-resistant special paint in the submerged area, and to reduce the amount of special paint and the amount of painting work. Therefore, at the time of maintenance inspection for secular change after tension mooring, the area that requires underwater work is reduced, so the amount of work for maintenance management is reduced. Moreover, since the submerged area is small, the steel material weight can also be reduced.

  Further, since the upper mooring portion of the tension mooring line can be maintained on the surface of the water, the work of attaching the tension mooring line, the tension adjustment work, the maintenance check work and the like can be carried out in the air, and the workability is improved. Accordingly, the work time is shortened, and the cost for these work can be reduced. In addition, when the length of the tension mooring line is adjusted when the lower mooring part sinks unequal due to earthquake etc. after the floating body is installed, the mooring part above the water surface that performs the work is above the water surface, Underwater work is unnecessary, and adjustment work can be performed efficiently.

  Further, according to the system for supporting the tension mooring floating body system of the present invention, and the floating body towing method and installation method using the same, during the operations such as towing, installation, maintenance, and removal of the floating body, The arranged support system can sufficiently support the work such as towing and installation of the floating body.

  In particular, it is possible to generate a restoring force against the inclination of the floating body by temporarily fixing the supporting floating body to the mooring portion on the surface of the floating body for operations such as towing, installation, maintenance, and removal. Thereby, the inclination of the floating body can be suppressed and the posture can be stabilized, and the risk of rollover can be significantly reduced. As a result, it is possible to eliminate the need for support by a large offshore crane in operations such as towing and installation of the floating body, and cost reduction can be achieved.

It is the figure which showed the structure of the tension mooring floating body system in embodiment which concerns on this invention. It is the figure which showed the mooring part on the water surface in embodiment which concerns on this invention. It is the figure which showed the other structure of the mooring part on the water surface. It is the top view which showed the shape of the support floating body. It is the fragmentary sectional side view which showed the installation of the support floating body. It is the side view which showed the towing state of the floating body which has arrange | positioned the support floating body. It is the side view which showed the semi-submerged state of the floating body which has arrange | positioned the support floating body. It is the side view which showed the tension mooring state of the tension mooring floating body, and the separation state of the support floating body. It is the figure which showed the structure of the tension mooring floating body system of a prior art. It is the figure which showed the state of the tension mooring floating body system called the mini TLP of a prior art.

  Hereinafter, a tension mooring floating body system, a support system, and a floating body towing method and installation method using the support system according to the present invention will be described with reference to the drawings. Here, in particular, a tension mooring floating body system in which a wind power generator is mounted on an upper structure supported by the floating body will be described as an example, but the present invention is not limited to the wind power generator, and the upper structure includes an oil well drilling device, The present invention can also be applied to a tension mooring floating system equipped with other plants and measuring devices.

  First, the tension mooring floating body system 1 according to the embodiment of the present invention will be described. The tension mooring floating body system 1 is a system for a tension mooring floating body (mini tension leg platform). As shown in FIG. 1, an upper structure 11 on which a wind power generator 10 is mounted, and the upper structure. A floating body 12 for supporting the object 11, a plurality of tension mooring lines 13 called tendons for mooring the floating body 12 (three in one place in FIG. 1), and a tension mooring line 13 Are fixed to the bottom 2 of the seabed, lake bottom, riverbed or the like.

  The floating body 12 supports the weight of the upper structure 11 with buoyancy and maintains the upper structure 11 at a preset height above the water surface. The floating body 12 includes a central columnar body 12a formed of a cylinder or a polygonal column for supporting the upper structure 11, a submerged buoyancy body 12b provided under the central columnar body 12a, and the central columnar body 12a. A water surface coupling body 12c arranged radially extending around the water surface and a water surface mooring section 12d disposed at an end of the water surface coupling body 12c are configured.

  The central columnar body 12a is called a center column, and a submerged buoyancy body 12b is provided below the central columnar body 12a. The submerged buoyancy body 12b is a structure that generates most of the buoyancy of the tension mooring float 1. The central columnar body 12a and the submerged buoyancy body 12b have, for example, a hollow structure and are configured to generate buoyancy using steel, prestressed concrete (PC), or the like.

  The submerged buoyancy body 12b is a part that generates main buoyancy for supporting the upper structure at a predetermined height on the water surface, and has a shape that is not easily affected by waves, for example, the upper part has a truncated cone shape. The intermediate part is formed in a cylindrical shape and the lower part is formed in an inverted truncated cone shape. By making this lower part into an inverted conical shape, the influence of waves can be reduced compared to the case where the lower part of the cylinder is simply formed as a plane. The submerged buoyancy body 12b is provided with a ballast tank, a ballast pump, a ballast adjusting device, and the like as necessary in order to generate buoyancy changes during towing and mooring.

  And one end of the water surface coupling body 12c is connected to the upper part of the center columnar body 12a, and the other end is connected to the water surface mooring part 12d. The water surface connector 12c is configured such that all or half or more of the surface area is above the water surface 3 in a still water state, that is, in a still water surface state. The water surface mooring portion 12d is also configured so that the entire water surface mooring portion 12d is above the water surface 3 and is not submerged when the water is still. The upper end portion of the tension mooring line 13 for tension mooring the floating body 12 is fixed to the upper mooring portion 15c provided above the water surface of the water surface mooring portion 12d.

  The water surface connector 12c is configured so that the whole is above the water surface 3 so as not to be submerged at the time of still water, for example, a steel structure such as a brace structure using steel, a truss structure, a ramen structure, etc. It has a high strength but a structure with a relatively small steel material weight and surface area. All or half or more of the surface area of the water surface connector 12c is configured to be above the water surface 3 during still water.

  Further, the water surface mooring part 12d is formed of a hollow columnar body having a hollow part 12h through which the tension mooring line 13 is inserted, and an upper mooring part 15c is disposed above the water surface mooring part 12d. It connects with the water surface coupling body 12c. In addition, as a horizontal cross-sectional shape of this mooring part 12d on the water surface, in addition to the circle shown in FIG. 2, a polygon such as a quadrangle, a polygon with rounded corners, and the like are conceivable. Moreover, as shown in FIG. 3, the protective cover 12e for the tension mooring line 13 may be provided.

  According to this configuration, the mooring portion 12d on the water surface is provided on the water surface 3 and hardly passes through the water surface 3 except for a part of the protective cover 12e for the tension mooring line 13, etc. It hardly occurs. Therefore, the restoring force in the tension mooring floating body 1 after installation depends on the tension mooring line 13. When the upper mooring portion 15c is separated from the central columnar body 12a in plan view, the moment lever related to the inclination of the upper structure 11 is increased, so that the tension mooring line generated by the overturning moment acting on the floating body 12 and the upper structure 11 is increased. 13 changes in tension.

  The greater the separation distance, the larger the moment lever, so that a large restoring force can be obtained with a small change in tension of the same tension mooring line 13. Therefore, the water surface mooring part 12d is connected to the end of the water surface connector 12c, and the water surface mooring part 12d is provided at a position far away from the central columnar body 12a.

  A tension mooring line (tendon) 13 for tensioning and mooring the tension mooring floating body 1 to the anchoring bottom member 14 is formed of a steel chain, a cable, a rope, or the like, and the upper end of the tension mooring line 13 is a mooring portion on the water surface. A lower end portion of the upper anchoring portion 15c of 12d is attached to the lower anchoring portion 14c of the fixing bottomed member 14. At the time of mooring, the length of the tension mooring line 13 is adjusted so that tension is always applied to the tension mooring line 13 so that the floating body 12 is pulled into the water against the buoyancy of the floating body 12. Configure.

  The fixing bottom member 14 is a weight made of steel or concrete, also called a template, and is used as a gravity anchor that is submerged in the water bottom 2 and fixed by its own weight. In addition, you may use the piling (pile) fixed to the ground of the water bottom 2 as a fixed bottom member. The anchoring bottom member 14 is for mooring the floating body 12 at a preset position via the lower mooring portion 14c, the tension mooring line 13 and the upper mooring portion 15c. The part is fixed to the lower mooring part 14c.

  The size of the tension mooring floating body 1 is, for example, when the power generation amount is assumed to be 2 MW, and the windmill 10a has a rotating diameter of about 80 m when installed at a water depth of about 100 m to 200 m on the continental shelf. The rotating shaft 10b of the windmill 10a is about 75m above the water surface 3, the diameter of the central columnar body 12a of the floating body 12 is about 6m and the height is about 35m, and the maximum diameter of the submerged buoyancy body 12b is about 15m. The diameter of a circle passing through the centers of the three fixing bottom members 14 is about 60 m.

  In the tension mooring floating body system 1, the static restoring force of the floating body 1 after installation can be secured by the tension mooring cable 13, and stability can be ensured. The installation work and the length of the tension mooring cable 13 can be secured during and after installation. The adjustment work can be performed at a mooring section above the water surface 3 above the water surface 3.

Further, according to the tension mooring floating body system 1, the submerged buoyant body 12b in the lower part of the central columnar body 12a of the floating body 12 for supporting the upper structure 11 at a predetermined height on the water surface 3 can be restored. Since it can be a buoyant body for generating buoyancy that is not considered, the shape can be made less susceptible to the influence of waves.

  Thereby, since a submerged part and a submerged area become small, the water-resistant coating surface in a submerged area can be made small, and the amount of coating work and a coating material can be decreased. Accordingly, the maintenance area with respect to secular change after tension mooring is reduced, and the amount of work for maintenance management is reduced. Moreover, since the submerged area is small, the steel material weight can also be reduced.

  Further, in this tension mooring floating body system 1, by configuring the above-water surface connector 12c so that the whole surface area or half or more, preferably 2/3 or more, is above the water surface 3 at the time of still water, It is possible to reduce the amount of painting work and the amount of special paint by reducing the submerged area to zero or reducing the painting surface with the water-resistant and corrosion-resistant special paint in the submerged area. At the same time, at the time of maintenance inspection for secular change after tension mooring, the area requiring underwater work is reduced, so that maintenance management becomes easy.

  Moreover, since the upper mooring portion 12c of the tension mooring line 13 can be maintained on the water surface by configuring the mooring portion 12d on the water surface so that the entire mooring portion 12d is above the water surface 3 and does not submerge when the water is still. The attachment work of the cord 13, the tension adjustment work, the maintenance inspection work, and the like can be carried out in the air instead of underwater work.

  Therefore, workability is improved and work time is shortened, so that the cost for these work can be reduced. In addition, when the lower mooring portion 14c is sunk due to an earthquake or the like after installation, it is necessary to adjust the length of the tension mooring line 13 with respect to this unequal subsidence. In this case as well, the upper mooring portion 15c is required. Since it is on the water surface 3, underwater work becomes unnecessary and adjustment work can be performed efficiently.

  In particular, the underwater work area can be concentrated on the central columnar body 12a and the submerged buoyancy body 12b by allowing the water surface connector 12c and the water surface mooring part 12d to be completely on the water surface 3 during still water. Therefore, the efficiency of underwater work can be improved.

  However, the floating body 12 of the tension mooring floating body system 1 shown in FIG. 1 has a relatively high center of gravity, and the submerged buoyant body 12b that generates most of the buoyancy is directly below the central columnar body 12a. Because it is not, it becomes unstable in a situation where it is not moored.

  Therefore, in the present invention, in order to support the towing work, the installation work, the maintenance inspection work, the removal work, etc. of the floating body 12, the floating body 12 is temporarily moved to the mooring portion 12 d on the water surface by the towing and installation work. A support system having a support floating body 20 fixed to the head is used.

  Next, a support system according to an embodiment of the present invention will be described with reference to FIGS. This support system includes a support floating body 20.

  As shown in FIGS. 2 and 4, the support floating body 20 has a recess 21 into which a mooring portion 12 d on the water surface temporarily fixed for work such as towing, installation, maintenance, and removal of the floating body 12 enters. And are detachably joined along each of the water surface mooring portions 12d. 4 is a drawing mainly for showing the concave portion 21, and a take-up drum 23a (shown in FIG. 5) to be described later, a pulley 23b (shown in FIG. 5) for changing the direction of the tension mooring line 13, etc. Shown omitted.

  This joining is performed, for example, by pressing the joining member 22 against the surface mooring portion 12d by a hydraulic cylinder or the like. If the joining member 22 is configured to be movable in this manner, the fixing work for fixing the support floating body 20 to the mooring portion 12d on the water surface becomes easy. However, when joining with a simple configuration, the joining member 22 can be removed. It may be formed by a simple pipe structure (the cross section is not limited to a circle), and may be joined by bolts, temporary welding, or the like.

  The support floating body 20 is configured to float on the water surface 3 so as to have a restoring force in a direction to prevent the inclination, and is provided along the water surface mooring portion 12d. Thereby, since the support floating body 20 has a portion on the water surface on the water surface 3, the placement work on the water surface mooring portion 12d and the joining work with the joining member 22 are facilitated.

  For example, when the horizontal cross section of each mooring portion 12d on the water surface is close to a quadrangle, the concave portion 21 is formed by a U-shaped notch surrounding it.

  Also, as shown in FIG. 4, when the recess 21 is configured to be surrounded from the outside of the water surface mooring portion 12d, the integrated work is performed more than the case where the recess 21 is configured to be surrounded from the inside of the water surface mooring portion 12d. Sexuality improves. On the other hand, when the recess 21 is configured to be enclosed from the inside of the mooring portion 12d on the water surface, the occupied area in the horizontal plane of the support floating body 20 can be made smaller than when the recess 21 is configured to be surrounded from the outside. Therefore, it becomes possible to perform the integrated work in a narrow place. In addition, it becomes possible to tow a narrow channel.

  With this configuration, since the support floating body 20 has the concave portion 21 into which the water surface mooring portion 12d enters, the support floating body 20 increases in number along the water surface mooring portion 12d (three surfaces in FIG. 4). It becomes difficult for the floating body 20 to come off from the water surface mooring part 12d.

  In addition, the support floating body 20 is configured to have buoyancy and restoring force against the inclination of the floating body 12. Giving the restoring force to the inclination of the floating body 12 can be easily realized by providing the area of the water surface penetrating portion of the supporting floating body 20 so that the buoyancy change due to the fluctuation of the water level is generated. Since there is a large moment lever between the body 12a, it is easy to perform placement work and control of tilt control. In addition, it is preferable that the support floating body 20 includes a ballast tank so as to be able to adjust the buoyancy so as to have a role of adjusting the buoyancy during operations such as towing, installation, maintenance inspection, and removal.

  The support floating body 20 is temporarily fixed to the mooring portion 12 d on the water surface of the floating body 12 for operations such as towing and installation, and therefore tilts together with the floating body 12. Therefore, the support floating body 20 can secure the restoring force against the inclination of the floating body 12 and can stabilize the posture of the floating body 12. In other words, the support floating body 20 can suppress the heel (lateral inclination) and trim (vertical inclination) of the floating body 12, thereby enhancing the restoring force of the floating body 12.

  Since the support floating body 20 can remarkably enhance the restoring force related to the inclination of the floating body 12 with respect to the water surface, the posture of the floating body 12 can be stabilized and the fall can be prevented. As a result, sufficient support can be provided in operations such as towing and installation of the floating body 12, and support by a large offshore crane can be eliminated.

  In addition, by fixing the support floating body 20 to the mooring portion 12d on the water surface, a portion that requires disassembly and removal work of the support floating body 20 can always be maintained near the water surface 3. Therefore, for example, when the floating body 12 is installed, that is, when the support floating body 20 is detached after the tension mooring, underwater work for removal at a deep water depth that makes the work difficult can be eliminated.

  In addition, since the support floating body 20 is removed from the floating body 12 after tension mooring, the support floating body 20 can be repeatedly used when a large number of the floating bodies 12 of the tension mooring floating body system 1 are installed. As a result, the cost for towing and installation per unit of the floating body 12 can be reduced.

  Furthermore, for the tension mooring floating body system 1, the support floating body 20 is provided with a work support system. This work support system includes a winding system for a tension mooring line 13 for tensioning the floating body 12, a temporary mooring system for temporarily mooring the support floating body 20 along the floating body 12, and a ballast for the support floating body 20. The power supply system for the tension mooring floating body system 1, the power supply system for the support floating body 20, the power supply system for the floating body 12, or some combination thereof. FIG. 5 shows an example in which a winding system and various power supply systems are provided in the support floating body 20.

  As shown in FIG. 5, the winding system includes a winding drum 23a for winding the tension mooring line 13 and a pulley 23b for changing the direction of the tension mooring line 13, and the tension mooring line 13 is wound on the winding drum. Towed in a state of being wound around 23a, and in the installation water area, the tension mooring line 13 is unwound from the winding drum 23a via the pulley 23b, and the upper end of the tension mooring line 13 is fixed to the upper mooring part 15c. Drain and moor tension. In order to assist the removal of the pulley 23b after the tension mooring, it is convenient to mount a lifting device such as a small crane (not shown) on the support floating body 20.

  Further, the temporary mooring system includes a temporary mooring winch 24a and a temporary mooring line 24b as shown in FIG. 5, and temporarily moors the floating body 12 before tensioning the floating body 12 in the installation water area. This temporary mooring system is configured so that it can be lowered while being suspended to the bottom 2 while supporting the weight of the fixed bottom member 14 installed on the bottom 2.

  Further, the ballast adjusting system includes a ballast pump 25a, ballast tanks 25b and 25c, a sea chest 25d which is a seawater intake port, piping and a control valve for connecting them, as shown in FIG. When it is necessary to deepen the draft of the support floating body 20, seawater as ballast water is introduced from the sea chest 25 d by the ballast pump 25 a and injected into the ballast tanks 25 b and 25 c. When the draft of the support floating body 20 needs to be shallow, the ballast water is discharged from the ballast tanks 25b and 25c using the ballast pump 25a. By adjusting the ballast amount of these ballast tanks 25b and 25c, the subsidence amount and posture of the support floating body 20 itself are controlled.

  As the power supply system, there are a tension mooring floating body and a support floating body, but there is no need to provide them separately, and they may be common. For example, as shown in FIG. 5, the power supply system includes a fuel tank 26 a, a power generation engine 26 b, a power generation device 26 c, a switchboard 26 d, a control device, a charging device, and the like for supplying power to the floating body 12. Or the power supply for supplying power to each device of the support floating body 20 itself.

  Ballast adjustment of the floating body 12 is performed by adjusting the buoyancy of the submerged buoyancy body 12b. In addition, the buoyancy adjustment system of the submerged buoyancy body 12b includes, for example, a ballast pump, a ballast tank, a sea chest, a pipe, a control valve, and the like disposed below the submergence buoyancy body 12b.

  When it is necessary to deepen the draft of the floating body 12, seawater as ballast water is introduced from each sea chest in the submerged buoyancy body 12 b and injected into the ballast tank by a ballast pump. When it is necessary to make the draft of the floating body 12 shallower or to reduce the overall weight of the floating body by increasing the tension of the tension mooring line 13, the ballast water is discharged from the ballast tank using the respective ballast pumps. Discharge. The draft and posture of the floating body 12 are adjusted by adjusting the ballast amount of the submerged buoyancy body 12b.

  By providing this work support system in the support floating body 20, it is possible to sufficiently support in operations such as towing and installation. Moreover, the space of the support floating body 20 can be made to function as a work table at the time of towing and installation. Thereby, in the prior art, the work ship that has been supporting power supply etc. can be used only for towing for movement, so a work support system is not required on the work ship side, This will expand the range of work vessels that can be used.

  Moreover, since some or all of the incidental facilities are provided in the support floating body 20, some or all of the incidental facilities on the floating body 12 side can be omitted, and the cost of the entire apparatus of the floating body 12 can be reduced. Further, when a large number of floating bodies 12 are installed, the support floating body 20 can be used repeatedly to reduce costs for operations such as towing and installation of each floating body 12.

  Next, a method for towing the floating body 12 using the support floating body 20 having the above configuration will be described. In this towing, as shown in FIG. 6, when the tension mooring floating body 12 is towed, the supporting floating body 20 is towed in a state of being fixed to the floating body 12.

  In the construction in the dock before that, the floating body 12 is assembled on the upper part of the fixed bottom member 14, and the lower ends of the temporary mooring line 24b and the tension mooring line 13 are attached. The support floating body 20 is arranged on the water surface of the support floating body 20 separated from the floating body 12 with respect to the floating body 12 via a mount or the like, if necessary, in the upper part of the fixed bottom member 14 in the dock. After arrange | positioning so that the mooring part 12d may enter, the support floating body 20 is joined to the mooring part 12d on the water surface. Then, water is poured into the dock and the dock is taken out.

  FIG. 6 shows a state where the floating body 12 is pulled out from the building dock and towed, and the support floating body 20 is fixed to the floating body 12 in a state where the ballast water is not loaded on the ballast tank of the floating body 12. . At the same time, the fixed bottom member 14 is suspended by the tension mooring line 13 and the temporary mooring line 24 b below the support floating body 20. About half of the ballast water is poured into the fixed bottom member 14 so that the submerged buoyant body 12 b of the floating body 12 is on the water surface 3.

  In this state, the submerged buoyant body 12b penetrates the water surface 3 and contributes to the restoring force to some extent, but the height of the center of gravity of the floating body 12 from the water surface 3 is large and unstable, and it is easy to fall down. A large restoring force is generated by the floating body 20 for use, and a fall is prevented. In this state, it will be towed to the installation water area by a working ship such as a tugboat.

  According to this method, when the floating body 12 is towed, it is towed in a state of being arranged along the support floating body 20, so that the inclination of the floating body 12 can be suppressed by the support floating body 20, and the restoring force can be secured and the floating body 12 can be secured. Can be stabilized. Therefore, the towing work can be sufficiently supported, and the support by the large offshore crane can be eliminated.

  Next, a method for installing the floating body 12 using the support floating body 20 having the above-described configuration will be described. In this installation work, after being submerged from the towing state of FIG. 6 to the semi-submersible state of FIG. 7, tension mooring is performed to obtain the installation state of FIG.

  FIG. 7 shows that the state shown in FIG. 6 is lowered to the draft at the time of tension mooring by further injecting ballast water into the fixed bottom member 14 and injecting ballast water into the ballast tank of the submerged buoyancy body 12b. In other words, the entire mooring portion 12d on the water surface is on the water surface 3.

  In this state, the height of the center of gravity of the floating body 12 from the water surface 3 is lower than in the state of FIG. 6, but the portion penetrating the water surface 3 is less with the central columnar body 12a, and further against the inclination The contribution to restoring power is also small. In this state, since it is more unstable and easily falls, a large restoring force is generated by the support floating body 20 from the floating state of FIG. 6 to the semi-submerged state of FIG. 7 to prevent the fall.

  After the floating body 12 is submerged to the state of FIG. 7, the temporary mooring line 24 b and the tension mooring line 13 are extended and lowered to the bottom 2 while supporting the suspended anchoring bottom member 14 with the temporary mooring line 24 b. . Thereafter, additional ballast water concrete or the like is poured into the fixing bottom member 14 to fix the fixing bottom member 14 to the bottom 2. After the fixing, the temporary mooring line 24b is loosened, the tension mooring line 13 is stretched, the length of the tension mooring line 13 and the amount of settlement of the tension mooring floating body 1 are adjusted, and the upper end side of the tension mooring line 13 is connected to the surface mooring portion 12d. The upper mooring part 15c is fixed.

  Thereafter, the ballast water in the ballast tank of the submerged buoyant body 12b is drained, the entire weight of the floating body is reduced from the buoyancy, and a predetermined tension is generated on the tension mooring line 13. When the predetermined tension is generated and the floating body 12 is tensioned and moored, the support floating body 20 is separated from the floating body 12.

  The separation of the support floating body 20 is preferably performed at a position where the separation work on the water surface can be easily performed. The support floating body 20 is separated, and then the support floating body 20 is moved by a work boat or the like to separate the support floating body 20 from the surface mooring portion 12d. Due to the tension mooring by the tension mooring line 13 and the separation of the support floating body 20, an installation state as shown in FIG. 8 is obtained.

  According to this installation method, when the floating body 12 is installed, the installation work is performed in a state in which the support floating body 20 is fixedly arranged on the mooring portion 12d on the water surface, so that the inclination of the floating body 12 is suppressed by the support floating body 20, Installation work can be performed in a state where the restoring force is secured and the posture of the floating body 12 is stabilized. Therefore, the posture of the floating body 12 can be stabilized and the support by the large offshore crane for preventing the fall can be eliminated.

  Furthermore, according to this installation method, the fixed bottom member 14 is lowered while supporting the weight by the temporary mooring system provided on the support floating body 20 side. A facility such as a winch for lowering the material 14 to the bottom of the water becomes unnecessary.

  Therefore, according to the support system for the tension mooring floating body system 1 and the towing method and the installation method of the floating body 12 using the support system, in the towing work towing the floating body 12 to the installation water area, To increase the stability of the floating body 12, and when the floating body 12 is installed on the ocean, the support floating body 20 is more sufficient when the floating body 12 is shifted from the floating state before the mooring to the semi-submersible state. A restoring force can be applied to prevent the floating body 12 from falling. Further, in the installation work such as the sinking work to the bottom 2 of the anchoring anchoring member 14 for fixing the tension mooring cable 13 of the floating body 12 and the tensioning force adjustment of the tension mooring cable 13, the power supply system is operated, The mooring winch 24a, the ballast pump 25a for posture adjustment, and the like can be operated to function as a work table. As a result, during towing and installation of the floating body 12, the towing and installation work of the floating body 12 can be supported by the support floating body 20 that is temporarily arranged at least during towing or during installation work.

  In addition, since the support floating body 20 is removed from the tension mooring floating body 1 after the tension mooring, the support floating body 20 can be repeatedly used when a large number of the floating bodies 12 are installed. As a result, the cost of towing and installation per one floating body 12 can be reduced.

  Further, the support floating body 20 can be used for maintenance inspection work and removal work of the floating body 20 and can support these maintenance inspection work and removal work. The cost of maintenance inspection and removal per unit can also be reduced.

  The tension mooring floating body system of the present invention is a shape that is not easily affected by waves by making the submerged buoyant body of the floating body for supporting the superstructure simply a shape for generating buoyancy without considering the restoring force against the inclination of the floating body. In addition, the submerged area can be reduced, and the upper mooring part of the tension mooring line is maintained on the water surface, so that the tension mooring line can be attached, adjusted for tension, and maintained and inspected. Since underwater work can be avoided, it can be used as a tension mooring floating body system for a tension mooring floating body equipped with a wind power generation device, an oil well drilling device, other plants, measuring devices, etc. as an upper structure.

  In addition, the support system of the present invention and the floating tow method and installation method using the support system include at least one of the towing work, the installation work, the maintenance inspection work, and the removal work of the floating body of the tension mooring floating system. When it is carried out, the support floating body temporarily arranged can sufficiently support the towing and installation work of the tension mooring floating body. Therefore, various support systems for the tension mooring floating body, and the floating body using this support system It can be used as a towing method and installation method.

1, 1X, 1Y Tension mooring floating body system 2 Water bottom 3 Water surface 10 Wind power generator 11 Upper structure 12 Floating body 12a Central columnar body (center column)
12b Submerged buoyancy body 12c Water surface connector 12d Water surface mooring part 13 Tension mooring line (Tendon)
DESCRIPTION OF SYMBOLS 14 Fixed bottoming member 14c Lower mooring part 15c Upper mooring part 20 Support floating body 21 Recessed part 22 Joining member 23a Winding drum 23b Pulley 24a Temporary mooring winch 24b Temporary mooring cable

Claims (8)

  A tension comprising a floating body for supporting the superstructure, a plurality of tension mooring lines for mooring the floating body, and a fixing subsidence member for fixing the tension mooring lines to the bottom of the water In the moored floating body system, the floating body is provided at a central columnar body for supporting the weight of the upper structure by buoyancy and supporting the upper structure above the water surface, and at a lower part of the central columnar body. A submerged buoyancy body, a water surface connecting body radially extending from the central columnar body, and an upper end of the tension mooring line are fixed at the end of the water surface connecting body. The water surface mooring portion is configured so that all or half or more of the surface area of the water surface coupling body is above the water surface when the water is still, and the water surface mooring portion is above the water surface when the water is still. Tension mooring floating system characterized by .   In order to support at least one of the towing operation, installation operation, maintenance inspection operation, and removal operation of the floating body of the tension mooring floating body system according to claim 1, the tension mooring floating system is temporarily fixed to the water surface mooring portion of the floating body. A support system comprising a support floating body.   3. The support system according to claim 2, wherein the support floating body has a buoyancy greater than its own weight and a restoring force against the inclination of the float.   Winding system of tension mooring line for tension mooring the floating body, temporary mooring system for temporarily mooring the floating body for support, system for ballast adjustment of the floating body, system for ballast adjustment of the floating body for support, the water surface A power support system for an upper mooring unit, a power supply system for the support floating body, a work support system configured by at least one of the power supply system for the floating body, or some combination is provided in the support floating body. The support system according to claim 3.   The support floating body has a recess into which the water surface mooring part enters, and is joined to the water surface mooring part when supporting the work, and after the work support ends, the support floating body is The support system according to claim 2, 3 or 4, wherein the support system is separated from the mooring portion on the water surface.   A towing method for a floating body, wherein the tow of the floating body of the tension moored floating body system according to claim 1 is towed in a state where the support system according to claim 2, 3, 4 or 5 is used.   The installation method of the floating body of the tension mooring floating body system of Claim 1 WHEREIN: The system for assistance of Claim 2, 3, 4 or 5 is used, The installation method of the floating body characterized by the above-mentioned.   The support floating body is formed with a temporary mooring system for temporarily mooring the floating body, and when the floating body is installed by the temporary mooring system, the tension mooring cable is installed by the temporary mooring system in the installation water area of the floating body. The anchoring bottom member moored to the bottom of the water is sunk to the bottom of the water, the support floating body is temporarily moored, and then moored by the tension mooring line, and after mooring by the tension mooring line, 8. The floating body installation method according to claim 7, wherein the temporary mooring is released.

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