WO2011107589A1

WO2011107589A1 - Tower for a wind turbine

Info

Publication number: WO2011107589A1
Application number: PCT/EP2011/053307
Authority: WO
Inventors: Andreas Kiehn
Original assignee: Suzlon Energy Gmbh
Priority date: 2010-03-05
Filing date: 2011-03-04
Publication date: 2011-09-09
Also published as: DE102010039316A1

Abstract

The present invention relates to an anchoring system for a steel tube tower of a wind turbine. The anchoring system (1) according to the invention is designed to clamp a wind turbine directly or indirectly against a base (15) for a wind turbine and comprises a tower (10) or a lower tower segment which has, at least at its lower end, a flange (14), at least one clamping element (19, 21) and an attachment device (30). The flange here has an underside facing the base in the mounted state and an upper side facing away from the base as well as an end face which runs in the circumferential direction around the flange and connects the upper and lower sides. The attachment device is embodied according to the invention as a clamping claw or collet chuck, and in the mounted stated it is connected directly or indirectly to the base via the clamping element in such a way that it transmits a pressing force which acts on the upper side of the flange, and is directed vertically downwards, i.e. in the direction of the base, by which pressing force the flange of the tower is clamped against the base of the wind turbine.

Description

Tower for a wind turbine

The present invention relates to an anchoring system for a steel tube tower of a wind turbine. Very high tubular steel towers require a certain rigidity because of the vibration and the natural frequency. This requires a large tower diameter or a large wall thickness. The anchoring of tubular steel towers is often realized with the aid of a flange, particularly often with the aid of a T-flange, which is usually braced over two annularly arranged rows of anchor bolts with the foundation. Since the transport of tubular steel towers from the production halls of the manufacturers to the installation sites usually has to be realized by means of heavy-load transports over land, the height of bridges results in a maximum transport height of 4.5 meters. The tower segments are usually transported horizontally during transport, which is why the maximum diameter of the tower segments must not exceed the transport height in the area of the flange. The distance between the road and the transported tower segments corresponds to approximately 0.1 to 0.2 meters for most heavy goods vehicles. For this reason, the maximum diameter of the tower segments including the flange must not be greater than 4.3 or 4.4 meters. In order to provide a sufficient footprint and space for the positioning of the anchor bolts, the outer flange width - that is, the part of the T-flange, which extends beyond the diameter of the lateral surface - greater than 0.25, usually greater than zero Be 3 meters. This is especially true for towers over 80 meters high. For this reason, the maximum diameter of the tower in the area of the lateral surface without flange when using conventional anchoring systems must not be greater than a certain amount, preferably 4.0 or 4.05 meters. Because of the transport-related cross-sectional limitation of the tower segments, therefore, other measures must be taken in wind turbines with large towers to ensure sufficient rigidity of the tower. One possibility is to design the tower segments with a larger wall thickness. However, this leads to a higher material consumption, which has a negative cost.

An object of the invention is thus to realize an increased rigidity without an increased material consumption.

The object is achieved by an anchoring system for a wind turbine with the features of the main claim 1.

The anchoring system according to the invention is designed to brace a wind turbine directly or indirectly against a foundation for a wind turbine and comprises a tower or a lower tower segment, which at least at its lower end has a flange, at least one clamping element and a fastening device. In this case, the flange has an underside facing the foundation in the mounted state and an upper side facing away from the foundation as well as an end face running circumferentially around the flange, connecting the upper and lower sides.

The fastening device according to the invention is designed as a clamping jaw or collet and in the assembled state via the clamping element directly or indirectly connected to the foundation so that it transmits a force acting on the top of the flange, vertically downward, ie in the direction of the foundation contact force, through which Flange of the tower is braced against the foundation of the wind turbine. Such an anchoring system has the effect that the outer flange width, that is to say the part of the flange which projects beyond the diameter of the lateral surface, can be reduced because the forces required for anchoring are no longer transmitted by anchor bolts, which are guided by holes in the flange, but with the help of a designed as a collet chuck or fixing device. Preferably, the flange of the tower accordingly has no holes or recesses; Particularly preferably, the top and bottom of the flange are aligned substantially orthogonal to the vertically oriented tower axis. This causes a simpler transport of the tower according to the invention.

This fastening device is - except for a bearing surface, which rests on the top of the flange of the tower - arranged in the assembled state radially to the flange and clamped by means of clamping elements - for example, also anchor bolts or tension strands - with the foundation. In the assembled state, accordingly, the clamping elements of the fastening device in the radial direction at a greater distance from the axis of the tower, as the circumferential end face of the flange. By clamping the clamping elements of the fastening device directly or indirectly with the foundation, the fastening device exerts on the support surface a locally defined contact pressure on the top of the flange of the tower, so that it is braced directly or indirectly with the foundation.

According to a preferred embodiment of the invention, the fastening device is designed as a collet. As a collet, the fastening device has in addition to a bearing surface, via which the contact force is transmitted to the flange, and a support surface which serves as a support of the collet and defined by their distance from the support surface, the length of the power arm according to the lever law. Preferably, the anchoring system has a plurality of fastening devices, which are preferably designed as collets and are preferably arranged symmetrically in the mounted state around the circumference of the tower in the region of the flange. Particularly preferred are the Fastening devices in this case formed so that they form a segmented annular disc in the assembled state, the inner radius is smaller than the outer radius of the flange, so that a defined bearing surface is formed by the difference between the inner radius of the segmented annular disc and the outer radius of the flange ,

According to a further embodiment of the invention, the fastening device is designed as a clamping jaw. Although a clamping jaw also has a bearing surface for transmitting the contact pressure on the flange, but not on a support surface. Accordingly, the clamping element, which is connected to the clamping claw, absorb transverse forces in order to prevent slippage of the bearing surface of the flange. In order to avoid these transverse forces when using clamping claws as fastening devices, the anchoring system preferably has a plurality - ie at least two - preferably symmetrically around the circumference of the tower in the region of the flange arranged clamping jaws, which form a segmented annular disc in the mounted state and connected to each other are.

According to a further embodiment of the invention, the fastening device is designed as a non-segmented annular disc - ie annular disk in one piece - which is pushed over the tower during assembly from above. If the tower of the wind turbine or the lower tower segment has a T-flange at the lower end, preferably at least one fastening device is arranged in the assembled state so that it braces the radially inwardly pointing flange of the tower or the lower tower segment against the foundation , Preferably, the tower of the anchoring system has an outer radius in the region of the lateral surface without flange of more than 1, 8 meters, more preferably of more than 1, 9 or even more than 2 meters. The said outer flange of the tower preferably has a width of less than 0.25 meters, more preferably of at most 0.2 or even at most 0.15 meters.

According to another embodiment, the wall thickness of the tower is less than 5 parts per thousand of the height of the tower. According to a particularly preferred embodiment, the wall thickness is less than 4.5 parts per thousand, and more preferably less than 4.2 parts per thousand of the tower height. These two embodiments are particularly advantageous when the tower is higher than 80 meters, in particular higher than 100 meters, or preferably higher than 120 meters. A further aspect of the invention relates to an inventive fastening device for the anchoring system described.

This fastening device, which is designed in the mounted state to transmit a contact pressure on the upper side of a flange of a tower of a wind turbine, according to the invention has a mounted in the state downwardly oriented and the top of the flange facing support surface which is annular disc-shaped or ring-disk segment-shaped and is preferably limited by a peripheral abutting edge. The abutting edge has in a horizontal plane - at least in the region in which it abuts against the support surface - has a radius of curvature which corresponds to half the diameter of the outer flange, in particular a radius of curvature of between 2.05 and 2.15 meters, and preferably between 2.1 and 2.15 meters.

More preferably, the fastening device is made of more than 90% cast iron. A further aspect of the invention relates to a tubular tower segment, preferably but not limited to, preferably made of steel and / or GRP for the tower of an onshore wind turbine. According to the invention has the lower tubular tower segment an outer radius in the region of the lateral surface without flange of more than 1, 8 meters, more preferably of more than 1, 9 or even more than 2 meters. At the same time, this tower segment according to the invention has an outer flange at the lower end, which has a width of less than 0.25 meters, more preferably of at most 0.2 or even at most 0.15 meters.

A further aspect of the invention relates to a wind turbine, which has at least one tower with the above-mentioned tubular tower segment, a machine house, a rotor shaft, a rotor hub and rotor blades and the above-mentioned fastening device.

Further details of the invention will become apparent from the drawings with reference to the description.

In the drawings shows:

1 is a side view of a tower for a wind turbine with tubular tower segments,

Fig. 2 is a side view of the lower part of the tower of the wind turbine of Fig. 1, with reduced flange width

3 shows a schematic illustration of the anchoring system according to the invention for a wind turbine, FIG. 4 shows a schematic representation of a further embodiment of the anchoring system according to the invention for a wind turbine,

Fig. 5 is a plan view of the anchoring system according to the invention with a plurality of fastening devices. 1 shows a plan view of a wind turbine designed as an on-shore system. The nacelle with rotor shaft and the rotor blades of the wind turbine connected via a hub to the rotor shaft rest on a tower 10 composed of tubular segments 12. The individual tubular segments are formed according to the invention in one piece, ie not of composite half shells and preferably of such type as used for on-shore facilities. The tower 10 has a height h of more than 90 meters in the assembled state.

FIG. 2 shows the lower end of the wind turbine according to FIG. 1. In this case, the lower end of the tower 10 has a flange 14, which has a substantially orthogonal to the vertical tower axis 1 1 extending top and bottom and extending between the top and bottom face. With the underside of its flange 14, the tower 10 rests on a foundation fixture 16, a so-called anchor cage, which is fixed to the foundation 15. The tower 10 shown here or the lower tower segment 12 does not correspond to the prior art, because he / it has dimensions, which only together with an anchoring system 1 according to the invention a secure bracing of the tower 10 with the foundation fixture 16 and thus with the foundation 15 ensure. Accordingly, the tower 10 shown here and the lower tower segment 12 represents an independent aspect of the invention.

At its lower end, the tower 10 in the region of the lateral surface, ie without the outer flange 14 _a , an outer diameter D _M of 3.8 meters. In the region of the flange 14 _a , the tower has an outer diameter of D _F of 4.2 meters. 3 shows a schematic cross-sectional illustration of the anchoring system 1 according to the invention for an onshore wind turbine. In detail, it is shown here as the lower tower segment 12, which has an inner 14, and an outer 14 _a Has flange, is braced with the foundation fixture 16 and thus also with the foundation 15. In this case, the outer flange 14 _a is clamped by means of a fastening device 30, which represents an independent aspect of the invention. The inner flange 14, according to the embodiment shown here by means of clamping screw 18 and clamping nut 20 is clamped to the foundation fixture 16.

The fastening device 30 shown here is designed as a collet because it comprises both a support surface 32, as well as a support surface 34. To achieve that the fastening device 30 is a vertically downward contact force on the support surface 32 on the outer flange 14 _{a of} the tower 10, the fastening device 30 in the assembled state with the help of the clamping elements 19, 21, which are designed as a clamping screw 19 and clamping nut 21, with the foundation fixture 16 and thus indirectly clamped to the foundation 15.

In order to ensure that the fastening device 30 during tightening of the clamping elements 19, 21 not with the support surface 32 side of the outer flange 14 _a slipping or unwanted transverse forces and bending moments on the clamping members 19, act 21 is formed the fixing device 30 as the collet. The support surface 34 can be regarded as a support of the collet, wherein the distance between the support surface 32 and the support surface 34 defines the power arm in the sense of the law of levers. Unwanted bending moments, which act on the clamping elements 19, 21, are avoided by this design.

In order to provide a defined bearing surface 32, a recess is provided in the fastening device 30, by means of which the bearing surface 32 on the one hand and a joint edge 33 on the other hand are defined. The abutting edge 33 is in the assembled state at the circumferential end face of the outer flange 14 _a and accordingly has a radius of curvature of 2.1 meters in the horizontal plane. The support surface 32 corresponds to a circular disc segment.

4 shows a schematic illustration of a further embodiment of the anchoring system 1 according to the invention for a wind turbine. According to this embodiment, the tower 10 and the lower tower segment 12 has a T-flange 14, wherein in the assembled state at least one fastening device 30, the radially inwardly facing flange (14,) of the tower (10) braced against the foundation (15) ,

5 shows a plan view of the anchoring system 1 with a plurality of fastening devices 30.

The lower tubular tower segment 12 can be seen in the center of the drawing. Contrary to tubular tower segments 10 according to the prior art, this segment has a wall height W _s of less than 45 millimeters at a tower height of 90 meters and according to the invention possesses a ratio between wall thickness W _s and tower height h of less than 45 per thousand.

As a dashed line, the peripheral edge of the outer flange 14 _a with the diameter D _F can be seen. Overlapping in the region of the support surfaces 32 rest - otherwise laterally arranged radially further outward - a plurality of fasteners 30 on the outer flange 14 _a . The fastening devices 30 are connected to one another in connection areas 36. This increases the rigidity of the anchoring system 1.

The feature combinations disclosed in the described exemplary embodiments are not intended to limit the invention, but rather the features of the different embodiments can also be combined with one another. List of Symbols Tower 21 Clamping element

Tower axis 30 Fastening device tubular tower segments 32 bearing surface

Flange 33 butt edge

, Inner flange 34 support surface

a Outer flange 36 connection area

Foundation A distance

Foundation component DM Tower diameter in the area of the jacket

clamping screw

D _F tower diameter in the area clamping element of the flange

Clamping nut W _s wall thickness

Claims

claims

1. anchoring system (1) for a wind turbine,

with a lower tower segment (12) for a tower (10) of a wind turbine, which has a flange (14) at its lower end,

with at least one clamping element (19, 21) which can be connected to a foundation (15) for a wind turbine,

characterized in that a fastening device (30) designed as a clamping jaw or collet is connected in the mounted state via the clamping element (19, 21) directly or indirectly to the foundation (15) so that a by the connection of the clamping element (19, 21) with the foundation (15) generated and transmitted via the fastening device (30), acting on an upper surface of the flange (14), vertically downward pressing force bracing the flange (14) of the lower tower segment (12) and thus the tower (10 ) against the foundation (15) causes.

2. anchoring system (1) according to claim 1, characterized in that the clamping device connected to the fastening device (30) (19, 21) in the assembled state at a distance (A) to a tower axis (1 1) with the foundation (15) is arranged clamped, which is greater than half the diameter (D _F ) of the outer flange (14 _a ) of the tower segment (12).

3. anchoring system (1) according to any one of the preceding claims, characterized in that the fastening device (30) is designed as a collet and a support (32) and a support surface (34), wherein the support surface (32) in the mounted state for transmitting the contact pressure to the flange (14), while the support surface (34) in the assembled state at a distance from the tower axis (1 1) is arranged, which is greater than half the diameter (D _F ) of the flange (14 ) of the tower segment (12). and serves as a support for the collet.

4. anchoring system (1) according to one of claims 1 to 3, characterized in that in the mounted state, a plurality of fastening devices (30) are arranged distributed around the circumference of the tower segment (1 2).

5. anchoring system (1) according to claim 4, characterized in that the

Fastening devices (30) form a segmented annular disc resting on the flange (14).

6. anchoring system (1) according to any one of claims 1, 2, 4 or 5, characterized in that the fastening device (30) is designed as a clamping claw and in the assembled state rests on the flange (14) of the tower segment (1 2) and this clamped against the foundation (15).

7. anchoring system (1) according to one of the preceding claims, characterized in that the tower segment (12) has a T-flange (14), wherein in the mounted state at least one fastening devices (30) the radially inwardly facing flange (14,) of the tower segment (12) braced against the foundation (1 5).

8. anchoring system (1) according to one of the preceding claims, characterized in that the tower segment (12) in the region of the lateral surface without flange (14) has a diameter (DM) of more than 3.6 meters, preferably more than 3.8 Meters and more preferably of more than 4 meters.

9. anchoring system (1) according to any one of the preceding claims, characterized in that the flange (14) of the tower segment (12) has an externa ßeren diameter (D _F ), which is less than 0.5 meters, preferably at most 0.4 meters and more preferably at most 0.3 meters above the diameter (D _M ) of the tower segment (12) without flange (14).

10. fastening device (30) for an anchoring system (1) according to one of claims 1 to 9, which has a bearing surface (32) which is adapted to transmit in the mounted state of a contact pressure on the flange (14), characterized that the bearing surface is defined by an abutment edge (33) having in a horizontal plane a radius of curvature corresponding to half the diameter (D _F) of the FEU ßeren flange (14 _a), or a curvature radius of 2.05 to 2 , 15 meters and preferably between 2.1 and 2.15 meters.

1 1. Tubular tower segment (1 2) for an anchoring system (1) according to one of claims 1 to 10, with a diameter (DM) without flange (14) of more than 3.8 meters, preferably more than 3.9 meters, and more preferably of more than 4 meters and a diameter (D _F ) of the outer flange (14 _a ) which is at most 0.5 meters, preferably at most 0.4 meters and more preferably at most 0.3 meters above the diameter (DM) of the tower without Flange (14) is located.

12. tubular tower segment (12) according to claim 13 made of steel or GRP.

13. tower (10) for a wind turbine (1) with an anchoring system (1) according to one of the preceding claims, characterized in that the wall thickness (W _s ) of the tower (10) to the tower height (h) less than 5 parts per thousand, preferably 4.5 parts per thousand, and more preferably 4.3 parts per thousand.

14. Tower (10) according to claim 14, characterized in that the tower (10) has a height (h) of 80 meters, preferably a height (h) of 100 meters, and in particular a height (h) of 120 meters.

15. Wind turbine comprising a tower (10), a rotatably mounted thereon nacelle, a rotor shaft, a rotor hub characterized by anchoring system according to one of claims 1 to 9.