JP6270527B2 - Installation method of offshore wind power generation equipment - Google Patents

Description

  The present invention relates to a method for constructing a spar-type offshore wind power generation facility installed on a relatively deep sea.

  Conventionally, mainly power generation methods such as hydropower, thermal power, and nuclear power have been adopted, but in recent years, wind power generation that generates power using natural wind has attracted attention from the viewpoint of effective use of the environment and natural energy. . There are two types of wind power generation equipment: land-based and water-based (mainly sea-based). In Japan, where mountainous landforms are located behind the coastal area, there are few plains where stable winds can be expected in the coastal area. It is in. On the other hand, Japan is surrounded on all sides by the sea, and it has the advantage that the wind suitable for power generation can be easily obtained on the sea and there are few installation restrictions. In recent years, therefore, many offshore wind power generation facilities or floating structures have been proposed.

  For example, in Patent Document 1 below, a lower floating body in which upper and lower lid bodies and a cylindrical precast concrete block continuously installed between them are integrally joined with a PC steel material, and a PC steel material on the lower floating body. The upper float is composed of a precast concrete block having a smaller diameter than the precast concrete block and the upper lid, and a plurality of ballast tanks are formed inside the lower float by a partition wall inside the upper float. Has proposed a floating structure for offshore wind power generation in which a plurality of watertight compartments are formed by partition walls. Since this patent document 1 floats in a standing state like a fishing float, it is called a “spar type”.

  When installing a wind power generation tower on the spar type floating body, it is desirable to work in a bay where the waves are calm, but the floating body's inundation (the part below the surface of the water) is about 70m deep, while the water depth in the bay is deep. Is generally shallower than this, so construction in the bay is difficult. For this reason, tower installation work must be performed outside the bay where the water depth is deep, but when it is performed outside the bay, the waves are higher than in the bay. It was extremely difficult and dangerous to install the tower because the floating body and crane ship had different rocking characteristics. Therefore, since it was unavoidable to select a period when the waves were calm, the number of construction days per year was limited, and the standby time for heavy machinery was prolonged, increasing costs.

  In view of such problems, Patent Document 2 below proposes a floating structure for performing operations such as installation and maintenance of the floating structure in a stable state. Specifically, it is a floating type floating body structure that floats on water, the floating body main body configured to float on the water, the legs disposed on the floating body main body, and the legs on the bottom of the water. A floating structure that is configured to be able to switch the floating body main body between a floating state and a bottomed state in a water area in which the floating body main body can float. Proposed.

  The bottoming means includes a ballast tank disposed in the floating body main body, and a ballast control means for controlling pouring / draining of the ballast tank. The floating body is filled with water by the ballast control means. Means for lowering the main body part to ground the leg part to the bottom of the water; elevating means for supporting the leg part so that it can be raised and lowered with respect to the floating body main body part; elevating control means for controlling the elevating means; And a means for driving the elevating means by the elevating control means so that the legs are grounded to the water bottom.

JP 2009-18671 A JP2012-45981A

  According to the floating structure according to Patent Document 2, in order to perform the installation work of the upper structure (tower, nacelle, blade, etc.) with the floating structure bottomed on the seabed, Thus, there is an advantage that the installation work can be performed in a stable state that is not easily affected by the above.

  However, it is good if the sea floor is flat, but the shape of the sea bottom is often inclined, and even if it is initially flat, uneven subsidence occurs due to uneven load, resulting in a floating structure. When tilted, the top end surface of the floating structure is tilted rather than horizontal, and there is a problem that the lower end of the tower cannot be connected.

  Moreover, in the said patent document 2, it is set as the structure which has the raising / lowering means which supports the said leg part so that raising / lowering is possible with respect to the said floating body main body part, and the raising / lowering control means which controls this raising / lowering means as a bottoming means. It is disclosed. With this bottoming means, it is possible to adjust the inclination of the floating body. However, if such a bottoming means is provided for each floating body, there is a problem that the manufacturing cost increases significantly.

  Therefore, the main problem of the present invention is that it is possible to install superstructures (towers, nacelles, blades, etc.) in a stable state that is not easily affected by waves and winds while reducing costs, making it easy and safe on the ocean. It is to provide a construction method for offshore wind power generation equipment that realizes a simple construction.

In order to solve the above-mentioned problems, the present invention according to claim 1 includes a spar-type floating body, a mooring line connected to the floating body, a tower standing on the floating body, and equipment installed above the tower. An offshore wind power generation facility construction method comprising a nacelle and a plurality of windmill blades,
A tower is erected on a floating body that has been erected on the ocean, and the floating body is grounded in advance on the bottom of the sea in the offshore bay area where the nacelle and windmill blades are attached, and standing upright. Set up a grounding stand for
On the ocean adjacent to the production yard, the floating body is floated sideways on the sea, transported to the sea work area by a towed ship, and then the ballast is placed inside the floating body to float the floating body in an upright state. A first step of sinking the floating body and placing it on the bottom frame by
A second step of attaching a tower, a nacelle and a blade to the upper part of the floating body by a crane installed in a crane ship with the floating body bottomed;
There is provided a method for constructing an offshore wind power generation facility, comprising: a third step of placing a mooring line after floating the floating body on the ocean by discharging the ballast, towing to an installation sea area, and then installing a mooring line.

In the first aspect of the invention, in a marine work area outside the bay where the water depth is deep, a grounding base for installing the floating body and standing upright in advance is installed on the bottom of the sea in advance. After transporting to the sea working area, the floating body is floated in an upright state by throwing ballast inside the floating body, and the floating body is further sunk by placing ballast, and then the floating body is grounded. In this state, a tower, a nacelle and a blade are attached to the upper part of the floating body.

  Therefore, the floating body can stand upright without tilting or shaking, and the tower, nacelle and blade can be attached in a stable state, so that it can be installed easily and safely on the ocean. Is possible. Moreover, since the stability of the floating body is increased, the construction speed is improved and the construction cost can be reduced. Furthermore, since the bottom mount can be used repeatedly, more efficient construction is possible when installing a plurality of offshore wind power generation facilities such as wind farms. In addition, it is most desirable that the `` upright state '' in which the floating body is grounded to the bottom frame, but it is unavoidable that construction errors are inevitably caused. It may be slightly inclined.

  Compared to adding a bottoming function to the floating body as before, the cost per unit can be greatly reduced, and ground conditions are eased compared to directly landing on the seabed. Since it is possible to select an assembly area from a wider area, construction can be performed under better conditions such as waves, wind conditions, and water depth, and the number of buildings can be increased annually and the construction cost can be reduced. . Furthermore, since it is possible to select a sea area closer to the installation location even under the same sea area conditions, it is possible to shorten the towing time and the construction cost.

  According to a second aspect of the present invention, as the landing base, a base in which the shape of the sea bottom is measured in advance and the ground contact portion is adjusted so that the top surface is horizontal in the installed state is used. An offshore wind power plant construction method is provided.

  The invention according to claim 2 shows a first embodiment of the bottom cradle, and the top surface is horizontal only by sinking the bottom cradle on the seabed. In other words, the shape of the bottom of the sea is measured in advance, and according to the shape of the bottom of the sea, by setting a predetermined slope on the ground contact surface (bottom) to the sea bottom or by changing the leg length of the gantry, The top surface is automatically leveled.

  As a third aspect of the present invention, a base comprising a bottom base and at least three lift legs which are provided on the bottom base and whose leg length is adjustable by a lift control is used as the bottom base. A construction method of the offshore wind power generation facility according to claim 1 is provided.

  The invention described in claim 3 shows a second embodiment of the bottom mounting frame, and the top surface of the mounting frame can be adjusted horizontally by adjusting the leg length before or after being set on the seabed. It is.

  As described above, according to the present invention, it is possible to install an upper structure (a tower, a nacelle, a blade, etc.) in a stable state that is not easily affected by waves and winds, while reducing costs. And safe construction is realized.

1 is a schematic view of an offshore wind power generation facility 1 according to the present invention. 2 is a longitudinal sectional view of a floating body 2. FIG. The precast cylindrical body 12 (13) is shown, (A) is a longitudinal sectional view, (B) is a plan view (a view taken along the line B-B), and (C) is a bottom view (a view taken along the line C-C). FIG. 3 is a schematic diagram (A) and (B) of tight-bonding between precast cylindrical bodies 12 (13). It is a longitudinal cross-sectional view which shows an upper steel floating body structure part. It is construction procedure figure (the 1) of offshore wind power generation equipment. It is construction procedure figure (the 2) of offshore wind power generation equipment. It is construction procedure figure (the 3) of offshore wind power generation equipment. It is construction procedure figure (the 4) of offshore wind power generation equipment. It is a side view of the construction procedure figure (the 5) of the offshore wind power generation equipment. It is a front view of the construction procedure figure (the 5) of the offshore wind power generation equipment. It is construction procedure figure (the 6) of offshore wind power generation equipment. It is construction procedure figure (the 7) of offshore wind power generation equipment. It is a side view which shows the other example (the 1) of a bottom mounting stand. It is a side view which shows the other example (the 2) of a bottom mounting stand.

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

  As shown in FIG. 1, an offshore wind power generation facility 1 includes a floating body 2, mooring lines 4, 4... Connected to the floating body 2, a tower 5 standing on the floating body 2, and the tower. 5 is composed of a nacelle 6 installed at the top of 5 and a plurality of windmill blades 7, 7,.

  As shown in FIG. 2, the floating body 2 is formed by stacking a plurality of precast cylindrical bodies 12 to 13 made of concrete in the height direction, and the precast cylindrical bodies 12 to 13 are tightly coupled by a PC steel material. The lower concrete floating structure 2A and the upper steel floating structure 2B connected to the upper side of the lower concrete floating structure 2A, and the bottomed hollow part having an open upper end A spar-type floating body structure having The flooded water L of the floating body 2 is set to approximately 60 m or more in the case of a 2 MW class power generation facility.

  This will be described in more detail below.

  As shown in FIG. 2, the floating body 2 includes a bottomed cylindrical ballast portion 10, a lower concrete floating structure portion 2 </ b> A connected to the upper surface of the ballast portion 10, and the lower concrete floating structure portion. It consists of the upper steel floating body structure part 2B provided continuously on the upper side of 2A. The ballast portion 10 and the lower concrete floating structure portion 2A are all concrete precast members. A synthetic precast member 13 is interposed at the boundary between the lower concrete floating structure 2A and the upper steel floating structure 2B, and both are joined. The upper steel floating body structure portion 2B has a variable cross-sectional shape in which the outer diameter dimension is gradually reduced in the height direction. In the illustrated example, it has a two-stage variable cross-sectional shape.

  The lower concrete floating body structure portion 2 </ b> A is composed of a precast cylindrical body 12 made of concrete and a lower half portion of the synthetic precast member 13. As shown in FIG. 3, the precast cylindrical body 12 is a circular cylindrical precast member having the same cross section in the axial direction, and each is manufactured using the same mold or by centrifugal molding. The manufactured hollow precast member is used.

  In addition to the reinforcing bars 20, sheaths 21, 21... For inserting the PC steel bars 19 are embedded in the wall surface at appropriate intervals in the circumferential direction. A sheath widened portion 21a is formed at the lower end of the sheaths 21, 21... So that a coupler for connecting the PC steel bars 19 can be inserted, and a fixing anchor plate is fitted on the upper portion. A box opening portion 22 is provided for installation. In addition, a plurality of suspension fittings 23 are provided on the upper surface.

  As shown in FIG. 4 (A), the precast cylindrical bodies 12 are fastened by inserting the PC steel rods 19, 19... Extended upward from the lower-stage precast cylindrical body 12 into the sheaths 21, 21. However, if the precast cylindrical bodies 12 and 12 are stacked, the anchor plate 24 is fitted into the box opening portion 22, and tension is introduced into the PC steel bar 19 by the nut member 25 to achieve integration. A grout material is injected into the sheath 21 from the grout injection hole 27. The hole 24a formed in the anchor plate 24 is a grout injection confirmation hole, and the filling of the grout material is completed when the grout material is discharged from the confirmation hole.

  Next, as shown in FIG. 4 (B), when the coupler 26 is screwed into the protruding portion of the PC steel bar 19 and the upper PC steel bars 19, 19,. The PC steel rods 19, 19 are stacked while being inserted through the sheaths 21, 21 ... of the precast cylindrical body 12, and the procedure for fixing the PC steel rod 19 is sequentially repeated according to the above procedure. At this time, an adhesive 28 such as an epoxy resin or a sealing material is applied to the joint surface between the lower-stage precast tubular body 12 and the upper-stage precast tubular body 12 in order to ensure waterproofness and join the mating surfaces. .

  Next, the composite precast member 13 has a composite structure of a concrete precast tubular body 16 and a steel tubular body 17 as shown in FIG. These are manufactured integrally. The precast tubular body 16 has an outer diameter dimension obtained by reducing the thickness of the steel tubular body 17, and the lower half portion of the steel tubular body 17 is fitted on the outer periphery. The upper end surface of the precast cylindrical body 16 is a fastening surface of the PC steel rod 19.

  The upper steel floating body structure portion 2 </ b> B is composed of an upper half portion of the synthetic precast member 13 and steel tubular bodies 14 and 15. The lower-stage steel tubular body 14 has the same outer diameter as that of the synthetic precast member 13 and is connected to the synthetic precast member 13 by bolts, welding, or the like (in the illustrated example, bolt fastening). The upper-stage steel tubular body 15 has an outer diameter smaller than that of the lower-stage steel tubular body 14 and has a variable cross-sectional shape. They are connected by welding or the like (in the illustrated example, bolt fastening). The upper end of the upper steel tubular body 15 is left open, the boundary between the upper steel tubular body 15 and the lower steel tubular body 14 and the lower steel tubular body. A space is not partitioned at the boundary between 14 and the steel tubular body 17, and a hollow portion is formed inside the floating body 2.

  On the other hand, the tower 5 is made of steel, concrete, or PRC (prestressed reinforced concrete). Preferably, the tower 5 is made of steel so as to reduce the total weight. The nacelle 6 is a device equipped with a generator that converts the rotation of the windmill into electricity, a controller that can automatically change the angle of the blade, and the like.

[Construction procedure]
Hereinafter, based on FIGS. 6-12, the construction procedure of the said offshore wind power generation equipment 1 is explained in full detail.

(Preparation procedures)
In the marine work area where the tower 5 is erected on the floating body 2 standing on the ocean and the nacelle 6 and the wind turbine blades 7, 7... Are attached, the floating body 2 is grounded in advance on the bottom of the sea. A bottom stand 8 for standing up in the state is installed (see FIG. 9).

  As the landing base 8, for example, it is possible to measure the shape of the sea bottom in advance and adjust the sea bottom grounding portion so that the top surface is horizontal in the installed state. The shape of the sea floor can be measured to a certain degree of accuracy by, for example, multi-beam depth surveying or side scan sonar (sea floor survey). In the case of a structure such as a steel or concrete box as shown in FIG. 9, the “adjusting the seafloor grounding portion” means that a predetermined surface is provided on the bottom surface so that the top surface is horizontal when installed on the bottom surface. In the case of a steel frame structure, as shown in FIG. 14, the leg length (leg height) is adjusted in advance so that the upper surface is horizontal when installed on the sea bottom.

(First procedure)
On the ocean adjacent to the production yard, as shown in FIG. 6, the floating body 2 is floated sideways on the sea, and is towed to the offshore work area by the tow ship 18. In the lower concrete floating structure 2A and the upper steel floating structure 2B, the lower concrete floating structure 2A is heavier, so that the balance adjustment floating body 32 is floated, and a winch 33 installed on the floating structure 33 is provided. One end of the wire drawn out from is connected to the end of the lower concrete floating structure 2A, and the floating body 2 is adjusted to be horizontal. The upper end opening of the upper-stage steel cylindrical body 15 of the floating body 2 is closed. Further, the floating body 2 may be adjusted by pouring ballast water 31 (water or seawater) in a state of being floated sideways on the sea to adjust the flooding.

  In place of the method of towing by the towed ship 18, although not shown, the floating body 2 may be mounted on a carriage and transported to an offshore work area and floated offshore with a crane in the offshore work area. In this case, it is preferable not to put ballast such as ballast water or ballast material into the floating body 2.

  As shown in FIG. 7, when arriving at the sea work area, the ballast water 31 is poured, and the wire 2 is gradually drawn out from the winch 33 on the balance adjusting floating body 32, thereby slowly raising the floating body 2. Let In this state, since the ballast water is merely poured, the center of gravity is high, and the upright floating body 2 is in an unstable state.

  Next, as shown in FIG. 8, when the floating body 2 is raised, the ballast material 43 is put into the ballast portion 10. For example, a material ship 40 loaded with a ballast material 43 and a dredger 41 equipped with a large pump 42 are provided, and the ballast material 43 loaded on the material ship 40 is mixed with mixed water (water or water). After being mixed with the seawater), the fluid is transported to the dredger 41 through a hose extending to the dredger 41 and introduced into the floating body 2 through a hose extending from the large pump 42 installed in the dredger 41 to the inside of the float 2. At the same time, surplus water inside the floating body 2 is drained by a suction pump installed in the material ship 40. The ballast material 43 injected into the floating body 2 sinks to the bottom of the floating body 2 due to the specific gravity difference. The injection of the ballast material 43 gradually increases the flooding of the floating body 2. Accordingly, the wire 2 is fed out from the winch 33 on the balance adjusting floating body 32, thereby maintaining the upright state of the floating body 2. Note that the ballast material 43 can be charged by a loading hopper suspended by a hoist ship.

  As the ballast material 43, a powdery granular material having a specific gravity higher than that of water is used. Specifically, the ballast material 43 includes sand, gravel, minerals including barite, metal powder such as iron and lead, and metal particles. It is preferable that it consists of 1 type or multiple types of combinations among metals. Moreover, mortar can also be mixed suitably. By adjusting the material of the ballast material 43, the ballast material 43 having an appropriate specific gravity can be input.

  Next, as shown in FIG. 9, after adjusting the position of the floating body 2 so as to be directly above the bottom mounting base 8, the floating body 2 is submerged in the sea by pouring ballast water. Land on the top of the gantry. When the floating body 2 is grounded on the bottom mounting base 8, the floating body 2 is stabilized in an upright state along the vertical direction. In addition, the water injection of the ballast water can be performed by a large pump 42 mounted on the dredger 40, for example.

(Second procedure)
When the floating body 2 is bottomed on the bottom stand 8, as shown in FIGS. 10 and 11, a tower 5 having a nacelle 6 and windmill blades 7, 7,. The suspended crane 44a and the pull-in rope 44b are used to suspend the crane while maintaining a stable state, and the crane is installed (connected) to the upper portion of the floating body 2 by a tower fixing base bracket 34 (see FIG. 13).

  At this time, since the floating body 2 is bottomed and is in a stable state, it can be easily and safely installed on the ocean when the tower 5 or the like is attached. Moreover, since the floating body 2 is stable, the construction speed is improved and the construction cost can be reduced. Further, when installing a plurality of offshore wind power generation facilities such as wind farms, the assembly of a plurality of offshore wind power generation facilities 1, 1... Can be performed automatically.

  In the present embodiment, the nacelle 6 and the windmill blades 7, 7... Are assembled on the upper portion of the tower 5 and attached together, but the order of the tower 5, the nacelle 6, the windmill blades 7, 7,. May be attached separately.

(Third procedure)
When the installation of the tower 5, the nacelle 6 and the wind turbine blades 7, 7... Is completed and the assembly of the offshore wind power generation facility 1 is completed, the floating body 2 is floated again on the sea by draining ballast water, and is shown in FIG. Thus, the tow ship 18 is towed to the sea area where the wind power generation facility 1 is installed. The drainage of the ballast water can be performed by a suction pump installed in the material ship 40.

  In addition, a ballast pump may be installed in the floating body 2 in advance, and water may be injected or drained by the ballast pump.

  If it arrives at the installation sea area, as shown in FIG. 13, if the ballast water is poured into the floating body 2 and the submergence is adjusted, the mooring lines 4, 4,. The anchor is set on the seabed to stabilize the floating body 2, and the construction is completed.

(Another example of the bottom stand 8)
In the above embodiment, an example of a base in which the bottom contact portion is adjusted so that the top surface is horizontal in the installed state is shown as the bottom base 8, but as shown in FIG. It is also possible to provide a gantry 9 including at least three elevating legs 9B, 9B,... Which are provided on the landing base 9A and whose leg length is adjustable by elevating control. In this case, it is possible to adjust the landing base 9A horizontally by adjusting the lifting legs 9B, 9B, etc. after installing the landing base 9 on the sea floor without measuring the shape of the sea bottom in advance. It is.

[Other examples]
(1) In the above embodiment, in the second procedure of the first embodiment, a ballast material 43 mixed with water or seawater is introduced as the ballast to be introduced into the floating body 2, and excess water is drained. However, solidified bodies such as concrete may be added, or only water or seawater may be used. Moreover, a concrete block may be thrown into the inside, or a concrete ring may be externally fitted to the outer periphery of the concrete cylindrical body 12 on the upper side of the ballast portion 10, and these may be used in combination.
(2) Although it is desirable to remove the bottom mounting bases 8 and 9, they may be left as they are and may be stabilized by bottoming the floating body 2 during subsequent maintenance or during strong wind waves. .

  DESCRIPTION OF SYMBOLS 1 ... Offshore wind power generation equipment, 2 ... Floating body, 4 ... Mooring line, 5 ... Tower, 6 ... Nacelle, 7 ... Windmill blade, 8.9 ... Grounding frame, 40 ... Material ship, 41 ... Dredger, 42 ... Large pump 43 ... Ballast material

Claims (3)

An offshore wind power generation facility comprising a spar type floating body, a mooring line connected to the floating body, a tower erected on the floating body, a nacelle and a plurality of windmill blades installed above the tower A construction method,
A tower is erected on a floating body that has been erected on the ocean, and the floating body is grounded in advance on the bottom of the sea in the offshore bay area where the nacelle and windmill blades are attached, and standing upright. Set up a grounding stand for
On the ocean adjacent to the production yard, the floating body is floated sideways on the sea, transported to the sea work area by a towed ship, and then the ballast is placed inside the floating body to float the floating body in an upright state. A first step of sinking the floating body and placing it on the bottom frame by
A second step of attaching a tower, a nacelle and a blade to the upper part of the floating body by a crane installed in a crane ship with the floating body bottomed;
A method for constructing an offshore wind power generation facility, comprising: a third step of floating a floating body on the ocean by discharging the ballast, towing to an installation sea area, and then installing a mooring line.   The construction method of the offshore wind power generation equipment of Claim 1 which uses the base which measured the shape of a sea bottom beforehand and adjusted the seabed grounding part so that an upper surface may become horizontal in the installation state as the said bottom base.   2. The offshore wind power generation facility according to claim 1, wherein the bottom mounting base is a base including a bottoming base and at least three lifting legs which are provided on the bottom base and whose leg lengths are adjustable by lifting control. Construction method.

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