EP2422083A2

EP2422083A2 - Tower for a wind power plant

Info

Publication number: EP2422083A2
Application number: EP09776553A
Authority: EP
Inventors: Klaus HÜSEMANN; Willi Meiners
Original assignee: Ruukki Dortmund GmbH
Current assignee: Rautaruukki Oyj
Priority date: 2009-04-22
Filing date: 2009-04-22
Publication date: 2012-02-29
Also published as: CN102439303A; WO2010121630A3; WO2010121630A2; US8474212B2; US20120137621A1

Abstract

The invention relates to a tower for a wind power plant having a plurality of corner bars (1) for forming a mast construction, wherein the corner bars (1) are each made up of a plurality of partial profiles (2) connected to each other and having opposing connection areas (3a, 3b) at which the adjacent partial profiles (2) of a corner bar (1) can be connected to each other, and wherein the partial profiles (2) each have two kink points in cross section extending in the longitudinal direction of the partial profiles (2) in a segment located between opposite connection areas (3a, 3b) of the partial profile. The corner bars (1) are each formed of at least three partial profiles (2), wherein the at least three partial profiles (2) of a corner bar (1) form a closed overall profile having an annular cross section, and that the joints at the connection of connection areas (3a, 3b) of adjacent partial profiles (2) of a corner bar (1) are each flush with an adjacent joint of an adjacent corner bar (1) extending the corner bar (1) in the longitudinal direction.

Description

Tower for a wind turbine

The invention relates to a tower for a wind turbine with a plurality of Eckstielen to form a mast construction, wherein the corner posts are each composed of a plurality of interconnected sub-profiles, the opposite terminal areas, where adjacent sub-profiles of a Eckstiels are connected to each other, and wherein the sub-profiles respectively In cross-section, in a section lying between opposite connection regions of the partial profile, two kinks extending in the longitudinal extension direction of the partial profiles must have.

Truss tower constructions with Eckstielen made of angle profiles are known per se. With the height of the towers and with the size of the components mounted on the tower, in particular wind turbines, the load on the angle profiles increases. These loads can be met to some extent through the use of profiles with larger profile cross sections. However, the profile cross-sections can not be increased to any extent, since the production of angle profiles manufacturing restrictions subject.

There are numerous approaches to designing the corner handles of truss structures so that larger tower heights can be realized. For example, it is known to connect a plurality of angle profiles by welding, or to produce already in the production of a cross-shaped profile for corner handles. This profile design is not optimal in relation to the achieved area moments of inertia of the Eckstielkonstruktion.

In DE 103 08 176 A1 it is proposed to manufacture corner posts from a shaped steel whose profile has at least two flanks, the flanks

BESTATIGUNGSKOPIE are connected by means of a carrier. Such a designed lattice tower has the advantage that the profile of the corner stems is made stronger by the provision of an additional support. This results in corner handles with a comparison made of angle profiles conventional corner handles significantly improved buckling length.

Another way to build tall towers is to increase the number of corner posts, which is generally four, to meet the static specifications. In that case, the legs of the generally used rectangular angle profiles, which are connected by cross braces, are no longer in alignment, so that the connection of the extension struts does not take place parallel to the corresponding legs of the angle profiles. This is disadvantageous.

This problem can be addressed by the corner handles are composed of several sub-profiles, generally up to a number of four. In this solution, however, four corner handles are still used for the mast construction.

The disadvantage is that the important for the buckling stability radii of gyration are very low, since a large part of the cross-sectional area of the corner handles lies in the center of gravity. Accordingly, many intermediate supports of the corner handles by means of braces are necessary, which significantly increases the design effort.

Due to this problem construction for truss towers is advantageous in which the corner handles and the infill are formed from tubes. Here, the material concentration in the profile of the corner handles and in the profile of the flaws in a statically optimal arrangement is far removed from the neutral phase of the profile. However, the connections of the infills and the joints of the corner stems of such constructions are usually made by welding processes. Welded connections are expensive to manufacture. Furthermore, welds have a high notch effect, which is why they are dynamic claimed towers, as in wind turbines, must be greatly oversized and therefore hardly come into question. Especially against the background of new generations of wind turbines whose hub heights are over 80 m and / or whose power is over 2 megawatts, new approaches to the design of the truss structure have been developed due to the high structural and dynamic loading of the tower construction.

EP 1 442 807 A1 describes a corner pedestal profile optimized with regard to material usage and assembly. Here, a commercial I-profile, which has a central web and straps and is known under the name "Peiner-carrier", brought after the rolling process of the profile production in a new shape, so that the straps enclose an angle of 90 degrees with each other The new profile produced in this way can be open or closed, in which case the straps are welded together at the contact line, which is complicated because after the rolling of the I-profile, a further production process is necessary.

Advantage of the above construction with respect to angle profiles is the large cross-sectional area, which can be achieved with only one profile, and the opposite angular construction larger radius of gyration. The disadvantage is that the radius of gyration compared to a comparable tube is substantially (about factor 1, 4) smaller, and that struts of the corner handles do not initiate the forces in the direction of the center of gravity of the profile, so that the corner posts are twisted.

Another approach to the realization of Eckstielen with a closed profile is disclosed in DE 10 2005 012 817 A1. It describes the use of an existing from two open sub-profiles, closed in the assembled state, octagonal profile. The cross-section of the mounted profile corresponds to almost a tube. The sub-profiles are bolted. The struts are mounted by means of connecting plates between the sub-profiles, so that occurring forces are introduced by the struts almost centrally in the corner handle formed by the screwed part profiles. The mounting of the connection plates results in a gap between the screwed th partial profiles. Thus, the assembled profile in the static properties corresponds to a closed profile, therefore, among other things, if necessary, further screwing the part profiles between the struts necessary. At these additional screw connections, a spacer element, which is referred to as a binding plate, is arranged between the partial profiles. The necessary distance of the additional screws and thus the number of necessary binding plates results from the buckling stability of the profile half with the lower area moment of inertia.

Furthermore, it follows from the geometric conditions of the connection of the struts that the approximation of the Eckstielprofils leads to the statically favorable pipe shape, partial profiles with very different moment of inertia.

In a tower with z. B. quadrilateral stems of the aforementioned construction results for the outer plate of the Eckstieles an angle of about 270 degrees. Correspondingly, an angle of approximately 90 degrees results for the inner metal sheet. In this case, results for the inner metal sheet in relation to the outer metal sheet low moment of inertia, resulting in a significant number of additional fittings and tie plates between the strut connections. Since the glands must be checked regularly, resulting in corresponding costs, which depend on the number of binding sheets used. In the manufacture of the profiles has also been found that the production of closed octagonal profiles manufacturing technology is complicated.

DE 10 2007 039 957 A1 discloses a tower construction for the realization of large tower heights, in which two partial profiles are used for the construction of a corner post, which form a corner post segment mounted to form an overall profile. An inner contour, which is formed by the connection of three inner corners of the overall profile, has almost the shape of a triangle. The outer contour of the overall profile has connection areas for firing plates, on which struts of the lattice mast are fastened. The subprofiles have a different geometry and must also be provided with bends of up to 70 degrees. This is technically complex. In addition, severe deformations of the material cause the risk that strong internal stresses or previous damage will be introduced into the material as a result of the deformation.

The tower construction is carried out by screw connections, preferably at the site of the structure. In order to ensure accessibility to the screwing of the profile halves, handholes must be provided in the sub-profiles.

Object of the present invention is to provide an improved tower for a wind turbine with a Eckstielkonstruktion for lattice towers, in which the corner posts have the same area moment of inertia around both main axes sen and is as easy as possible to manufacture and assemble.

The object is achieved with the tower with the feature of claim 1.

Advantageous embodiments are described in the subclaims.

It is proposed that the corner handles are each formed from at least three sub-profiles, wherein the at least three sub-profiles of a corner stem form an annular profile closed in cross-section. This has the advantage that the sub-profiles can be identical, wherein in the region of the separating joints built-in cross struts are aligned to form a mast construction on a parting line of an adjacent corner post of star-shaped in a truss corner stalks.

The fact that in such a symmetrical construction, the joints of a connection of terminal portions of adjacent sub-profiles of a corner handle are each arranged in alignment with a respective adjacent parting line of the corner stem in the longitudinal direction extending adjacent corner post, the compound can be arranged one above the other Corner handles, ie the connection of two corner handle segments to a corner handle, simplify and optimize the power flow.

The partial profiles are preferably folded at the two kinks in the region between the connection areas with an internal angle of α of 120 ° to 160 °, preferably 140 °.

It is particularly advantageous if the connection regions are cut at opposite outer edges of a partial profile with an internal angle β of 110 °. In this case, the opposite, bevelled connection areas of adjacent sub-profiles, which are connected to one another at the connection areas, should be aligned parallel to one another. The connection areas of a sub-profile should then be aligned in cross-section at an angle in the range of 150 ° to 125 °, preferably of 110 ° to each other.

In this way, it is possible to form a cross-sectionally closed overall profile of the corner post from the sub-profiles, wherein the sub-profiles can be statically optimally connected to one another with the aid of the connection areas aligned parallel to one another.

Furthermore, it is advantageous if coupling plates are provided for the coupling of partial profiles, which are each connected at least to the two opposite connection areas of an associated sub-profile. With the aid of these coupling plates, the sub-profiles can be stiffened by the fact that their connection areas, which are otherwise only connected to connection areas of adjacent sub-profiles, are additionally stiffened by connection to one another. The coupling plates provide for a stiffening of the sub-profiles of the corner handles on the areas particularly stressed by the application of force of the cross braces, especially when the coupling plates are mounted in the region of the height of the cross braces.

It is particularly advantageous if at least two adjacent coupling plates of two adjoining, a corner stem forming Eckstielsegmente are interconnected. The coupling plates of two adjoining, a corner handle forming Eckstielsegmente but can also be made in one piece. In this way, the coupling plates can serve to connect the superimposed partial profiles of two Eckstielsegmente or corner handles.

Furthermore, it is advantageous if the coupling plates are bent at an angle δ in an area between 110 ° and 130 °, preferably 120 °, in a region lying between the connection points with the opposite connection regions of a sub-profile assigned. In this way, the coupling plates extend through the center of gravity of the associated corner handle, so that the attached at a height of a corner handle a plurality of coupling plates form a cuspid that runs through the center of gravity of the corner handle and the free ends are directed to the terminal portions of the sub-profiles of a corner handle. This bump star can be formed of several separate coupling plates or a one-piece star-shaped coupling plate.

The coupling plates can each be guided between two connection regions of adjacent partial profiles, with the adjacent partial profiles being connected to one another at the two connection regions and the coupling plate. For this purpose, the coupling plates recess, such. B. have holes that are adapted to corresponding mounting recesses / holes on the connection areas of the sub-profiles to pass through fastening bolts or rivets through the aligned recesses and thus to connect the sub-profiles at the terminal areas with each other and with the coupling plate.

Furthermore, it is advantageous if partial profiles of the lower Eckstielsegmente the mast construction have a different, preferably smaller material thickness than the sub-profiles at least one arranged above the lower Eckstielsegmente Eckstielsegmenten. In this way, the material consumption of material for the sub-profiles can be minimized. But it is also conceivable one Variation of the profile geometry depending on the different static and dynamic loads in the different height sections of the tower. Thus, the width and height of the cross section of the overall profile of the Eckstielsegmente in the lower part of the tower structure can be greater than in the upper Esrcich.

The designed as stated above tower preferably has a height of more than 80 m and is therefore suitable for larger loads and designed.

It is particularly advantageous if the corner posts are connected to one another via cross struts, wherein the cross struts mounted at a height on a corner post are arranged and aligned such that the longitudinal axes of the cross struts of a corner post meet in the center of gravity of the overall section of the corner post formed by the section sections.

The invention will be explained in more detail with reference to an embodiment with the accompanying drawings. Show it:

Figure 1 - cross-sectional view of a corner handle formed from three sub-profiles mix transverse strands at connection areas;

Figure 2 - Horizontal section through a tower with six star-shaped corner stems and cross struts between the corner stems;

Figure 3 - sketch of a section of two superimposed Eckstielsegmenten a multi-part Eckstiels;

Figure 4 - Horizontal cross section through a corner post with connecting areas connecting coupling plates;

Figure 5 - Horizontal cross-sectional view of a sub-profile with advantageous dimensions.

FIG. 1 shows a horizontal cross section through a corner post 1, which is formed from three identical sub-profiles 2. The sub-profiles 2 extend in a longitudinal direction (in the viewing direction) and have at the two free outer edges connecting portions 3a, 3b, at which adjacent sub-profiles 2 are interconnected. With the aid of these connection areas 3a, 3b, the sub-profiles 2 can be connected to one another in a ring-shaped manner to form a closed overall profile in order to form a corner post 1.

For this purpose, the connection areas 3a, 3b of adjacent sub-profiles 2 are aligned parallel to one another and can be screwed, welded, riveted or otherwise fastened together in this way.

At the connection of adjacent sub-profiles 2 with the connection areas 3a, 3b, there are joints which can be attached, for example by means of coupling plates 4, to cross-members 5. These cross struts 5 are used for Connection of several, a tower construction forming and distributed on a circumference arranged corner handles 1.

It can be seen that the partial profiles 2 are folded twice in the region between the opposing connection regions 3a, 3b by an angle α in each case. The angle α is in the range of 120 ° to 160 ° and is preferably about 140 °.

Furthermore, it is clear that the connection areas 3a, 3b are formed by folding the outer edges of the sub-profiles 2 by an angle ß. The angle β is in the range of 115 ° to 125 ° and is preferably about 110 °, taking into account the usual tolerances.

The connection regions 3a, 3b of a partial profile obtained by such folding are aligned at an angle / to one another, which is preferably in a range of 115 ° to 125 ° and is preferably approximately 120 °. The sub-profiles 2 of a corner part 1 are thus also aligned at an angle / of 115 ° to 125 ° and preferably about 120 ° to each other. Then, as shown, three sub-profiles 2 result in an annularly closed overall profile.

FIG. 2 shows a horizontal section through a tower construction 6 with six corner posts 2 arranged on a circumference U (star-shaped).

The corner posts 2 consist in the longitudinal direction of a plurality of Eckstielsegmenten arranged one above the other, which are each formed of three, preferably folded, formed from sheets sub-profiles 2. The construction shown by way of example can, for. B. be a lattice mast with six corner posts 2 and a height of the lattice mast of about 120 m. On the lattice mast is a wind turbine with a power z. B. of up to 2 megawatts arranged.

For stiffening corner handles 2 are mutually connected with cross struts 5, which are attached to each other assigning joints of opposite corner handles 1. In this context is also on the sketch in FIG 1 referenced.

It can be seen that the transverse struts 5 of a corner handle 1 are guided to the respectively immediately adjacent corner handles 1. In this way, a strut with four transverse struts 5 is provided at a height of one ΞeksUeis i per Ecksiiei 1.

FIG. 3 shows a sketch of a detail of two corner stalk segments 7, 8 of a corner stalk 1 arranged vertically one above the other. In this case, the upper corner leg segment 7 has a smaller cross section than the lower corner leg segment 8. It can also be seen that the corner leg segments 7, 8 are interconnected by means of central coupling plates 9, 10. These coupling plates 9, 10 form connecting elements, with which the stacked Eckstielsegmente 7, 8 are connected to each other and through which the overall profile of the corner handle 2 is stiffened.

FIG. 4 shows a sketch of an exemplary embodiment of a corner post 1, which is formed from three sub-profiles 2. The sub-profiles 2 are in turn each stiffened by means of coupling plates 11 each to a closed profile, wherein the coupling plates 11 are guided to the center of gravity of the corner handle 1 and form a connecting star.

These coupling plates 11 are preferably used in the middle height segment of the tower construction.

That for the overall profiles, d. H. the corner handles 1 used material is preferably a structural steel such. For example, a grade S 355 fine grain steel with a length of 12 m and a material thickness of 8 mm. However, the sub-profiles and / or transverse struts can also at least partially by non-metallic ma- materials such. As laminated carbon fibers or fibrous natural materials are formed.

Advantageous dimensions are outlined in FIG. In the embodiment shown in FIG. Subprofile 2 with a profile height of 108.34 mm and a profile width of 567.63 mm result in the following area moments of inertia for the subprofiles 2:

Each identical thickness I max = 141437000 mm ⁴ I min = 743263 mm ⁴

Overall profile: I total = 537327000 mm ⁴

The partial profiles 2 have an angle α of 140 degrees and two angles β of 110 degrees each. In the tower construction, accordingly, opposite connection areas 3a, 3b of the corner posts 2, which are aligned parallel to one another, result.

The angled connection areas 3a, 3b of the sub-profiles 2 have a length, on the one hand, the assembly of the coupling plates 11, d. H. the fittings, and on the other is designed to ensure the necessary stiffening of the profile.

The focus of the area moment of inertia lies in the center of gravity of the overall profile. The forces introduced by the struts of a connection height into the individual corner posts 1 are also aligned with the center of gravity of the area moment of inertia, whereby the torsional stress of the corner posts 1 is minimized.

The construction has the advantage that in the mounted state a nearly closed profile of the corner post 1 results, wherein the area moment of inertia of the main axes of the corner posts 1 are almost identical.

The overall profiles of the corner handles 1 form corner post segments 7, 8. The corner post segments 7, 8 are arranged in the vertical direction to each other and can nen z. B. by means of a central baffle, which may be, for example, as shown in Figure 3 coupling plates 9, 10 or the star-shaped coupling plates 11 of Figure 4. The central baffles can be made in one piece or even in several parts.

It is particularly advantageous if the central baffle plates consist of three interconnected coupling plates 11, as sketched in FIG. These baffles should be merged star-shaped as shown in the center of gravity. These one-piece and multi-part versions of the central star-shaped merged bump plates are referred to below as a cushions.

Compared with conventional coupling plates, the rollover stars have the manufacturing advantage that the individual central baffle plates of a cornerstroke joint consist of one part or of equal parts. By pre-assembly of the formed of three bent coupling plates 11 bumpers (see Figure 4), the assembly of the corner handles 1 is simplified. In addition, the cushioned star causes a stiffening of the Eckstielprofile to the areas particularly stressed by the application of force of the cross braces 5 points. By thus directed to the center of the corner handle 1 force application bending moments and torsion of the corner handles 1 over conventional Eckstielkonstruktionen, such. As Eckstielkonstruktionen of angle iron, reduced.

By mounting the bumpers for connecting the cross braces 5 results in a gap between the bolted sub-profiles 2. So that the assembled profile in the static properties corresponds to a closed profile, therefore, among other things, if necessary, further screwing the sub-profiles 2 between the cross-struts 5 is necessary. At the additional fittings are between the sub-profiles two binding plates are arranged.

As a rule, there is less static and dynamic load in higher segments of tower structures than in lower segments of tower structures. A particularly advantageous embodiment of the overall profiles results from a variation of the material thickness and / or by the variation of the profile geometry, such. B. the width and the height of the cross section of the overall profile. This makes it possible to minimize the material consumption of Profi I material. In particular, the use of fine grain structural steel is advantageous in this context, since from this the respective partial profiles can be manufactured exactly to the static requirements.

This optimization results in higher segments of tower structures usually resulting in a lower overall profile cross-section, as in the lower segments. This results in distances between the vertically arranged and bolted to the coupling plates 10, 11 or bumpers total profiles, the holes in the coupling plates 10, 11 or shocks are adjusted accordingly. Separate lining sheets are for a non-positive connection by z. B. screw connection no longer necessary.

It is also advantageous if the material thickness of lower Eckstielsegmente is lower than the thickness of upper Eckstielsegmente. This is z. B. depending on the respective spread of the corner handles 1.

Claims

Claims:

1 . Tower for a wind turbine with a plurality of corner posts (1) for forming a mast construction, wherein the corner posts (1) each composed of a plurality of interconnected sub-profiles (2) having opposite terminal portions (3a, 3b), in which adjacent sub-profiles ( 2) of a corner post (1) are connectable to each other, and wherein the sub-profiles (2) each in a between opposite

Having connecting portions (3a, 3b) of the sub-profile (2) lying in cross-section two in the longitudinal direction of the sub-profiles (2) extending kinks, characterized in that

- The corner posts (1) are each formed from at least three sub-profiles (2), wherein at least three sub-profiles (2) of a corner stem (1) form a cross-sectionally annular closed overall profile, and

- that the joints at the junction of terminal portions (3a, 3b) of adjacent sub-profiles (2) of a corner handle (1) each in alignment with a respective adjacent parting line of the corner post (1) in

Longitudinal direction extending, adjacent corner post (1) are arranged.

2. Tower according to claim 1, characterized in that the kinks have an internal angle (α) in the range of 120 ° to 160 °, preferably of 140 °.

3. Tower according to claim 1 or 2, characterized in that the connection areas (3a, 3b) are bent at the opposite outer edges of the long sides of a sub-profile (2) with an internal angle (ß) of 1 10 ° that the opposite bent connecting portions (3a, 3b) of adjacent sub-profiles (2), which are connected to the End regions are connected to each other, are aligned parallel to each other, and that the connection regions (3a, 3b) of a sub-profile (2) in cross-section in the range of 115 ° to 125 °, preferably of only 110 °, are aligned with each other.

4. Tower according to one of claims 1 to 3, characterized in that coupling plates (4, 9, 10, 11) are provided for coupling of sub-profiles (2), each with at least the two opposite terminal portions (3a, 3b) of an associated Part profiles (2) are connected.

5. Tower according to claim 4, characterized in that at least two adjacent coupling plates (4, 9, 10, 11) of two adjoining, a corner handle forming corner stems (1) are interconnected.

6. Tower according to claim 4, characterized in that the coupling plates (4, 9, 10, 11) of two adjacent, a corner stem segment forming corner handles (1) are made in one piece.

7. Tower according to one of claims 4 to 6, characterized in that the coupling plates (4, 9, 10, 1 1) in a between the connection points with the opposite connection areas (3a, 3b) of an associated part profile (2) lying in section an angle (δ) in the range of 1 10 ° to 130 °, preferably 120 °, are folded.

8. Tower according to one of the preceding claims, characterized in that the coupling plates (4, 9, 10, 1 1) in each case between two connection areas (3 a, 3 b) adjacent sub-profiles (2) are guided, wherein the adjacent sub-profiles (2) the two connection areas (3a,

3b) and the coupling plate (4, 9, 10, 1 1) are interconnected.

9. Tower according to one of the preceding claims, characterized shows that partial profiles (2) of the lower corner leg segments of the mast construction have a different, preferably smaller, material thickness than the partial profiles (2) of at least one corner leg segments arranged above the lower corner leg segments.

10. Tower according to one of the preceding claims, characterized in that corner handles (1) are connected to each other via cross braces (5), wherein at a height to a corner post (1) mounted cross braces (5) are arranged and aligned such that the longitudinal axes of the transverse struts (5) of a corner stem (1) meet in the center of gravity of the overall profile of the corner stem (1) formed by the sub-profiles (2).