Method for constructing offshore wind power generation facility

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

Conventionally, power generation methods such as hydropower, thermal power, and nuclear power generation have been mainly adopted, but in recent years, wind power generation that uses natural wind to generate power has attracted attention from the viewpoint of effective utilization of the environment and natural energy. There are two types of wind power generation equipment, one is a land-based type and the other is a water-mounted type (mainly on the sea). In Japan, which has mountainous terrain behind the coastal area, there are few plains where stable wind can be expected in the coastal area. It is in. On the other hand, Japan is surrounded on all sides by the sea, and has the advantages of being able to easily obtain wind suitable for power generation on the sea and having few restrictions on installation. Therefore, in recent years, 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 lids and a tubular precast concrete block continuously installed between them are integrally joined with a PC steel material, and a PC steel material attached to the lower floating body. It is composed of a precast concrete block having a diameter smaller than that of the precast concrete block and an upper floating body composed of an upper lid, which are integrally joined by a partition wall to form a plurality of ballast tanks inside the upper floating body. Has proposed a floating structure for offshore wind power generation in which multiple watertight compartments are formed by partition walls. This Patent Document 1 is called a "spar type" because it floats in an upright state like a fishing float.

On the other hand, when constructing offshore structures such as offshore wind power generation facilities, a construction method that suppresses the shaking of the pontoon and enables quick construction by using an SEP (Self Elevating Platform: self-elevating platform) pontoon. It has been proposed (see Patent Documents 2 and 3 below).

<p><patcit num="1"><text>Japanese Unexamined Patent Publication No. 2009-18671</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2004-1750</text></patcit><patcit num="3"><text>Japanese Unexamined Patent Publication No. 2006-37397</text></patcit></p>

<p> When installing a wind power generation tower on the spar type floating body, it is desirable to construct it in the bay where the waves are calm, but the draft of the floating body (the part below the water surface) is as deep as 70 m, while the water depth in the bay Is generally shallower than this, making it difficult to construct in the bay. For this reason, the installation work of the tower must be done outside the bay where the water depth is deep, but when it is done outside the bay, the waves are higher than inside the bay, so the floating body that sways in the waves is suspended by a crane vessel that also sways in the waves. It was extremely difficult and dangerous to install the tower because the floating body and the crane vessel have different rocking characteristics against waves. Therefore, since the construction must be performed at a time when the waves are calm, the number of construction days per year is limited, the waiting time of heavy machinery becomes long, and the cost increases.</p><p> Further, as described in Patent Documents 2 and 3, if a crane vessel such as an SEP vessel is used as a crane vessel, the shaking of the vessel can be suppressed at least, but the spar type. Since the water depth is close to 100m at the offshore installation site of wind power generation equipment with a floating structure, SEP pontoons with a maximum applicable water depth of only about 20m cannot be used.</p><p> On the other hand, in order to enable work in a bay where the water depth is shallow, a method of making the draft of the floating body shallow by removing the ballast water inside the floating body is conceivable, but when the draft is made shallow, the stability as a floating body becomes stable. It was dangerous to install a tower against such a floating body as it would be damaged.</p><p> Moreover, neither the floating body nor the windmill tower attached to it is grounded, and it is in a state of floating on the sea or moored or suspended in the air by a crane vessel or the like with a chain or wire, and sways due to waves or wind. When I started, I couldn't control the swing. In the case of light weight, a tugboat and a tugboat can be used, but since the floating body weighs about 3000 tons (tons) and the windmill tower weighs about 200 tons, it did not have a sufficient deterrent load against rocking.</p><p> Therefore, a main object of the present invention is to provide an offshore wind power generation facility capable of performing easy and safe construction at sea and ensuring stability in strong winds or waves, and a construction method thereof.</p>

<p> In order to solve the above problems, as the present invention according to claim 1, a floating body, a mooring line connected to the floating body, a tower erected on the floating body, and a nacelle installed at the top of the floating body. And a method of constructing an offshore wind power generation facility consisting of multiple wind turbine blades. At least when the tower is installed on the upper part of the floating body, the swing of the tower is controlled by the mass damper installed on the tower or the hanging jig of the crane that suspends the tower, and the tower is installed inside the floating body. The control moment gyro provided provides a method for constructing an offshore wind power generation facility, which is characterized by controlling the swing of the floating body.</p><p> In the invention according to claim 1, at least when the tower is installed on the upper part of the floating body, the swing of the tower is controlled by the mass damper installed on the tower or the hanging jig of the crane that suspends the tower. The swing of the floating body is controlled by a control moment gyro installed inside the floating body. Therefore, even during strong winds and / or waves at sea, the swing of the tower in the air suspended by the crane vessel is suppressed by the mass damper, and the swing of the floating body floating on the sea is suppressed by the control moment gyro. As a result of ensuring the stability of the tower and the floating body, it becomes possible to carry out easy and safe construction at sea without being affected by the weather and waves. The swing control of the tower by the mass damper targets at least the translational swing in the left-right direction with respect to the crane vessel, and the swing control of the floating body by the control moment gyro is the translational swing control of the floating body in at least the horizontal direction and the vertical axis. It is preferable to target the rotational swing around.</p><p> As the present invention according to claim 2, the method for constructing an offshore wind power generation facility according to claim 1, wherein the mass damper is installed below the suspension position of the tower is provided.</p><p> In the invention according to claim 2, by installing the mass damper below the suspension position of the tower, that is, on the lower surface side of the suspension jig of the crane or the tower portion below the suspension position, the swing of the lower end of the tower is effective. You will be able to control it.</p><p> According to the third aspect of the present invention, there is provided the method for constructing an offshore wind power generation facility according to any one of claims 1 and 2, wherein the control moment gyro is installed at a position equivalent to the height of the center of gravity of the floating body. ..</p><p> In the invention according to claim 3, the control moment gyro is installed at a position equivalent to the height of the center of gravity of the floating body so that the swing of the floating body can be effectively controlled.</p><p> The offshore wind power generation according to any one of claims 1 to 3, wherein at least three control moment gyros are arranged vertically in a state where the rotation axes of the flywheel are orthogonal to each other as the present invention according to claim 4. Equipment construction methods are provided.</p><p> In the invention according to claim 4, at least three control moment gyros can be arranged vertically side by side with the rotation axes of the flywheel orthogonal to each other so that the three-dimensional swing of the floating body can be controlled. become.</p><p> According to the first aspect of the present invention, a plurality of the control moment gyros are installed along the inner circumference of the floating body, and the rotation axis direction of the flywheel is made to coincide with the tangential direction of the floating body circumference. The construction method of the offshore wind power generation facility described in any of ~ 3 is provided.</p><p> In the invention according to claim 5, a plurality of control moment gyros are installed along the inner circumference of the floating body, and the rotation axis direction of the flywheel of each control moment gyro is made to coincide with the tangential direction of the floating body circumference. Pitching, rolling, and yawing around three orthogonal axes can be easily controlled.</p>

<p> As described in detail above, according to the present invention, it is possible to provide a method for constructing an offshore wind power generation facility that enables easy and safe construction at sea and ensures stability in strong winds or waves.</p>

<figref num="1">It is the schematic of the offshore wind power generation facility 1 which concerns on this invention.</figref><figref num="2">It is a vertical cross-sectional view of the floating body 2.</figref><figref num="3">The precast tubular body 12 (13) is shown, (A) is a vertical sectional view, (B) is a plan view (BB line arrow view), and (C) is a bottom view (CC line arrow view).</figref><figref num="4">It is a binding procedure diagram (A) (B) between the precast tubular bodies 12 (13).</figref><figref num="5">It is a vertical cross-sectional view which shows the floating body structure part made of upper steel.</figref><figref num="6">It is a construction procedure diagram (No. 1) of the offshore wind power generation facility 1.</figref><figref num="7">It is a construction procedure diagram (2) of the offshore wind power generation facility 1.</figref><figref num="8">It is a construction procedure diagram (No. 3) of the offshore wind power generation facility 1.</figref><figref num="9">It is a construction procedure diagram (4) of the offshore wind power generation facility 1.</figref><figref num="10">It is a side view of the construction procedure diagram (No. 5) of the offshore wind power generation facility 1.</figref><figref num="11">It is a front view of the construction procedure diagram (No. 5) of the offshore wind power generation facility 1.</figref><figref num="12">It is a construction procedure diagram (No. 6) of the offshore wind power generation facility 1.</figref><figref num="13">It is a perspective view of a mass damper 36.</figref><figref num="14">It is a conceptual diagram of the control moment gyro 35.</figref><figref num="15">It is sectional drawing of the floating body 2 which shows the installation state (the 1) of the control moment gyro 35.</figref><figref num="16">It is a cross-sectional view of the floating body 2 which shows the installation state (the 2) of the control moment gyro 35.</figref><figref num="17">It is a conceptual diagram which shows the control state of a floating body 2 by a control moment gyro 35.</figref><figref num="18">It is a construction procedure diagram of the offshore wind power generation facility 1 which concerns on another form example.</figref>

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

As shown in FIG. 1, the offshore wind power generation facility 1 includes a floating body 2, a deck 3 installed on the floating body 2, mooring lines 4, 4 ... Connected to the floating body 2, and the above. It consists of a tower 5 erected on the deck 3, a nacelle 6 installed at the top of the tower 5, and a plurality of wind turbine blades 7, 7 ...

Then, as shown in FIG. 2, the floating body 2 is made by stacking a plurality of concrete precast tubular bodies 12 to 13 in the height direction, and connecting the precast tubular bodies 12 to 13 with a PC steel material to integrate them. 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 with the upper end open. It is a spar-type floating structure having a structure. The draft 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.

Hereinafter, the details will be described in more detail.

As shown in FIG. 2, the floating body 2 includes a bottomed cylindrical ballast portion 10, a lower concrete floating structure portion 2A connected to the upper surface of the ballast portion 10, and a lower concrete floating structure portion. It consists of an upper steel floating structure 2B connected to the upper side of 2A. The ballast portion 10 and the lower concrete floating structure portion 2A are all made of 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 structure portion 2B has a modified cross-sectional shape in which the outer diameter dimension is gradually reduced in the height direction. In the illustrated example, it has a two-step variable cross-sectional shape.

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

In addition to the reinforcing bars 20, sheaths 21, 21 ... For inserting the PC steel rods 19 at appropriate intervals in the circumferential direction are embedded in the wall surface. A sheath diameter-expanded portion 21a is formed at the lower end of the sheath 21, 21 ... so that a coupler for connecting the PC steel rods 19 can be inserted, and an anchor plate for fixing is formed at the upper portion. A box punching portion 22 for fitting the steel is formed. Further, a plurality of hanging metal fittings 23 are provided on the upper surface.

As shown in FIG. 4A, the tightness between the precast tubular bodies 12 is such that the PC steel rods 19, 19 ... Extending upward from the lower precast tubular body 12 are sheathed 21, 21 .. When the precast tubular bodies 12 and 12 are stacked while being inserted through the., The anchor plate 24 is fitted into the box punching portion 22, and tension is introduced into the PC steel rod 19 by the nut member 25 to integrate them. Further, the grout material is injected into the sheath 21 through the grout injection hole 27. The hole 24a formed in the anchor plate 24 is a grout injection confirmation hole, and filling of the grout material is completed when the grout material is discharged from the confirmation hole.

Next, as shown in FIG. 4 (B), if the coupler 26 is screwed into the protruding portion of the PC steel rod 19 and the PC steel rods 19, 19 ... The PC steel rods 19, 19 ... Are stacked while being inserted into the sheaths 21, 21 ... Of the precast tubular body 12, and the procedure for fixing the PC steel rods 19 is sequentially repeated according to the above procedure. Stacked in the vertical direction. At this time, an adhesive 28 such as an epoxy resin or a sealing material is applied to the joint surface between the lower precast tubular body 12 and the upper precast tubular body 12 to ensure water stoppage and join the mating surfaces. ..

Next, as shown in FIG. 5, the synthetic precast member 13 has a composite structure of a concrete precast tubular body 16 and a steel tubular body 17. These are manufactured integrally. The precast tubular body 16 has an outer diameter dimension obtained by subtracting the thickness corresponding to the wall thickness of the steel tubular body 17, and the lower half portion of the steel tubular body 17 is fitted on the outer periphery thereof. The structure is such that the upper end surface of the precast tubular body 16 is the fastening surface of the PC steel rod 19.

The upper steel floating structure portion 2B is composed of an upper half portion of the synthetic precast member 13 and steel tubular bodies 14 and 15. The steel tubular body 14 on the lower stage side has the same outer diameter as the synthetic precast member 13, and is connected to the synthetic precast member 13 by bolts, welding, or the like (bolt fastening in the illustrated example). The steel tubular body 15 on the upper stage side has an outer diameter smaller than that of the steel tubular body 14 on the lower stage side and has a modified cross-sectional shape, and is bolted or bolted to the steel tubular body 14 on the lower stage side. It is connected by welding or the like (bolt fastening in the illustrated example). The upper end of the upper steel tubular body 15 is left open, and the boundary between the upper steel tubular body 15 and the lower steel tubular body 14 and the lower steel tubular body 14 are left open. The boundary between 14 and the steel tubular body 17 is not partitioned, 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), but it is preferable to use one made of steel so that the total weight is small. Further, the nacelle 6 is a device equipped with a generator that converts the rotation of the wind turbine into electricity, a controller that can automatically change the angle of the blade, and the like.

[Construction procedure] Hereinafter, the construction procedure of the offshore wind power generation facility 1 will be described in detail based on FIGS. 6 to 12.

(1st step) On the ocean adjacent to the production yard, as shown in Fig. 6, the floating body 2 is floated sideways on the sea and towed by the towing vessel 18 to the offshore installation location. A control moment gyro 35 is installed in advance inside the floating body 2. Since the lower concrete floating structure 2A and the upper steel floating structure 2B are heavier on the lower concrete floating structure 2A side, the balance adjustment floating body 32 is floated and installed on the floating body. One end of the wire drawn out from the winch 33 is connected to the end of the lower concrete floating structure portion 2A, and the floating body 2 is adjusted so as to be horizontal. The upper end opening of the upper steel tubular body 15 of the floating body 2 is closed. Further, the floating body 2 may be floated sideways on the sea and ballast water 31 (water or seawater) may be injected to adjust the draft.

Instead of the method of towing by the towing vessel 18, although not shown, a method of mounting the floating body 2 on a pontoon, transporting it to an offshore installation location, and floating it on the ocean with a crane at the offshore installation location may be used. In this case, it is preferable not to put ballast water or ballast material into the floating body 2.

(Second step) As shown in FIG. 7, when arriving at the offshore installation site, the ballast water 31 is injected and the wire is gradually drawn out from the winch 33 on the balance adjustment floating body 32 to slowly erect the floating body 2 upright. Stand up in a state.

As shown in FIG. 8, when the floating body 2 is erected, the ballast material 43 is put into the ballast portion 10. As the ballast material 43, a powder or granular material having a higher specific gravity than water is used, and specifically, it contains minerals including sand, gravel and barite, and metal powder and metal particles such as iron and lead. It is preferably composed of one or a combination of a plurality of metals. In addition, mortar can be mixed as appropriate. By adjusting the material of the ballast material 43, it becomes possible to input the ballast material 43 having an appropriate specific gravity.

As shown in FIG. 9, the deck 3 is installed on the floating body 2, one end of the mooring line 4 is tied to the floating body 2, and the other end is tied to an anchor sunk on the seabed to stabilize the floating body 2. Aim.

(Third step) As shown in FIGS. 10 and 11, a tower 5 equipped with a nacelle 6 and a plurality of wind turbine blades 7, 7 ... at the top is suspended above the floating body 2 by a crane installed on a crane vessel 44. Install. At this time, the mass damper 36 is installed on the hanging jig 44a of the tower 5 or the crane for suspending the tower 5. This controls the tower 5 to translate and swing at least in the left-right direction with respect to the crane vessel 44. Further, the control moment gyro 35 installed inside the floating body 2 controls at least the translational swing in the horizontal direction and the rotational swing around the vertical axis of the floating body 2.

Therefore, even during strong winds and / or waves at sea, the swing of the tower 5 in the air suspended by the crane vessel 44 is suppressed by the mass damper 36, and the swing of the floating body 2 floating on the sea is the control moment gyro. Since it is suppressed by 35, the stability of the tower 5 and the floating body 2 is ensured, and as a result, it is not easily affected by the weather and waves, and easy and safe construction at sea is possible.

Since the tower 5 is suspended at two points using a suspension balance jig by a crane, rotational movement is unlikely to occur, and at least translational movement in the left-right direction is predominant, so the mass damper 36, which is easy to control and inexpensive, is advantageous. is there.

On the other hand, the floating body 2 is difficult to control by a mass damper because it causes rotational swing (yaw) around the vertical axis in addition to horizontal swing in the front-back and left-right directions. Further, in the case of the floating body 2, since the added weight directly affects the draft, the control moment gyro having a small weight and a large drop in the swing control is advantageous.

In this embodiment, as shown in FIG. 10, since the calling rope 44b is stretched between the hanging jig 44a and the crane vessel 44 main body, the translational swing of the tower 5 with respect to the crane vessel 44 in the front-rear direction is Although suppressed, when the lead-in rope 44b is not used, a two-dimensional mass damper 36 that can control the translational swing in the front-rear direction in addition to the translational swing in the left-right direction with respect to the crane vessel 44 is used.

Further, as shown in FIGS. 10 and 11, when the tower 5 is supported by a plurality of hanging jigs in the vertical direction, the mass damper 36 is installed on the lowermost hanging jig 44a.

In the examples shown in FIGS. 10 and 11, the nacelle 6 and the wind turbine blades 7, 7 ... Are pre-installed on the top of the tower 5, but after the tower 5 is installed, the nacelle 6 and the wind turbine blades 7, 7 ... ... may be installed.

(4th step) When all the member mounting work is completed, as shown in FIG. 12, the tower 5 is fixed at the regular height position by the tower fixing base metal fitting 34 or the like, and the construction is completed.

By the way, the mass damper 36 and the control moment gyro 35 will be described in detail. As shown in FIG. 13, the mass damper 36 has a movable mass with respect to two parallel rails 36b and 36b provided on the frame 36a. A structure in which the 36c is provided so as to be able to travel, a tension spring 36d and a damper 36e for applying an urging force and a damping force to the traveling direction are provided, and an actuator 36f for giving a traveling drive to the movable mass 36c is provided. The actuator 36f drives the movable mass 36c to travel in the direction opposite to the direction in which the object on which the mass damper 36 is installed swings, thereby suppressing the translational swing of the object. In the illustrated example, a second frame 36g that similarly supports the frame 36a is provided in a direction orthogonal to the traveling direction of the movable mass 36c, so that translational swing in two orthogonal directions can be suppressed. However, as described above, it is sufficient that this construction method can be controlled in at least one direction (horizontal direction with respect to the crane vessel 44).

Further, as the mass damper 36, either an active mass damper or a passive mass damper can be used, and the active mode and the passive mode may be switched.

The mass damper 36 is preferably installed below the suspension position of the tower 5. In FIGS. 10 and 11, the crane is installed on the lower surface side of the hanging jig 44a or on the tower 5 below the lower surface side. As a result, the swing of the lower end of the tower 5 can be effectively controlled.

The mass damper 36 is removed after the tower 5 is installed.

On the other hand, as shown in FIG. 14, the control moment gyro 35 has a structure in which a fly wheel 35a rotating at a constant speed is supported by one or two gimbal mechanisms, and the angle of the control moment gyro 35 is increased by the rotation of the gimbal. The purpose is to absorb the angular momentum of the object by changing the direction while keeping the magnitude of the momentum constant.

The control moment gyro 35 is preferably installed at a position equivalent to the height of the center of gravity G of the floating body 2. As a result, the swing of the floating body 2 can be effectively controlled.

The control moment gyro 35 can be arranged in various forms with respect to the inside of the floating body 2. In the first example, as shown in FIG. 15, at least three control moment gyros 35 can be arranged vertically side by side with the rotation axes of the flywheel 35a orthogonal to each other. This makes it possible to control the three-dimensional swing of the floating body 2.

As a second example, as shown in FIG. 16, a plurality of control moment gyros 35 are installed along the inner circumference of the floating body 2, and in the illustrated example, four are installed at equal intervals, and each of them is installed in the direction of the rotation axis of the flywheel 35a. Can be installed so as to match the tangential direction of the inner circumference of the floating body 2. As a result, as shown in FIG. 17, the control moment gyro 35 is appropriately controlled for the pitching (Fig. (A)), rolling (Fig. (B)), and yawing (Fig. (C)) of the floating body 2. By doing so, these rotational fluctuations can be suppressed.

In addition, as in the second example, by installing the control moment gyro 35 along the inner circumference of the floating body 2, the gantry for installation becomes unnecessary as in the case of installing it in the center of the floating body 2, and it is installed. Work can be facilitated.

On the other hand, the control moment gyro 35 installed inside the floating body 2 at the time of construction is left as it is after the construction, and the stability of the wind power generation facility 1 is maintained by the control moment gyro 35 even when the offshore wind power generation facility 1 is in operation. Can be secured.

[Other form examples] (1) In the above embodiment, a predetermined ballast material 43 is used as the ballast, but a concrete block may be put inside, or a concrete ring is formed on the outer periphery of the concrete tubular body 12 on the upper side of the ballast portion 10. May be fitted on the outside. These may be used together. (2) In the above example, the tower 5 is erected directly on the deck 3 installed above the floating body 2, but as shown in FIG. 18, the tower 5 is at least on the deck 3 at the time of construction. It may be able to be moved up and down by the tower elevating facility 8 provided in the above, and can be accommodated inside the floating body 2. In the tower elevating equipment 8, for example, as shown in the figure, center hole jacks 9, 9 ... Are arranged around the base of the tower 5 at predetermined intervals, and a sheave 11 is provided at one end of the PC steel wire 10. After being wound, it is tightly connected to the lower end of the tower 5 through the center hole jack 9, and the tower 5 can be lowered and raised by the expansion and contraction operation of the center hole jack 9.

In the tower elevating equipment 8, the nacelle 6 is installed and the two wind turbine blades 7 and 7 are installed in a state where the tower 5 is pulled up to an arbitrary height position, and then the tower 5 is pulled up slightly. It is used when installing the remaining wind turbine blade 7.

After all the member installation work is completed, the tower elevating equipment 8 may be removed or left so that it can be used for subsequent maintenance or when lowering the tower 5 during strong winds or waves. May be good. Of course, the tower elevating equipment 8 may be newly installed at the time of the tower descent work.

1 ... Offshore wind farm, 2 ... Floating, 3 ... Deck, 4 ... Mooring line, 5 ... Tower, 6 ... Nacelle, 7 ... Windmill blade, 35 .. .Control Moment Gyro, 36 ... Mass Damper, 44 ... Crane Ship