WO2016083191A1

WO2016083191A1 - Wind turbine tower

Info

Publication number: WO2016083191A1
Application number: PCT/EP2015/076800
Authority: WO
Inventors: Horst Bendix; Heinz Schuster
Original assignee: Horst Bendix
Priority date: 2014-11-27
Filing date: 2015-11-17
Publication date: 2016-06-02
Also published as: DE102015000818B3

Abstract

The invention relates to the tower structure of wind turbines, which avoids the bending load of the tower from rotor force and hub height in that the point of intersection (14) of the tower verticals (2b), the hub height (17), and the lines of action of the guying elements (4) leads to a pressure load of the tower from the rotor force of the wind and tensile loads in guying elements (4) arranged all around, which are arranged between the foundations (8) and the upper fastening in the guying ring. The novel tower structure leads to significantly less material use.

Description

Wind turbine tower

The invention relates to the structure of tall guyed wind turbine towers. This bracing should have a low elongation. It is arranged such that the rotor force in hub height at the intersection of the tower vertical and the guy elements in compressive and tensile force and the tower at the same time within the guy ring on which the braces are arranged, despite the dormant guy system according to the changing wind direction always can turn into the wind. The invention is suitable in a first embodiment for wind turbines (WTG) with a rotatable nacelle on a fixed tower and in a second embodiment for wind turbines with directly mounted rotor on a rotatable tower.

Wind turbines are characterized in their present design mainly by fixed towers of different construction, which are mainly connected at hub height via a rotary connection with the nacelle. Upwind (windward side), ie in front of the tower, the complete rotor and behind the rotor in the nacelle of the drive train is arranged.

The more powerful systems lead with the larger rotor diameters to intrinsic masses of the associated components, which lead to the realization of larger hub heights to the limit of technical feasibility in both the construction and equipment, as well as the operation and service of the equipment.

At present, maximum construction height for wind turbines in Germany is b220 m above the site. State-of-the-art radio, measuring and control systems of the future will lead to new possibilities for security and information services and promote the pursuit of higher energy yields inland. Double hub heights - compared to the previous average of 120 to 130 m - will lead to multiple revenues and thus to a lower number of locations. Higher towers for wind turbines require a new structure of the towers. Double the height must not lead to multiple assets and costs. With a rotatable tower and a retaining ring for the compression struts used is attempted according to the document EP 2 065 593 B1, by a support of the tower To create possibilities for the production of higher towers. Because of their massive education they are called legs. Their angle to the vertical tower axis is 10 ° to 30 °. These trained and arranged legs are not suitable for large tower heights. So that the tower can be rotated relative to the upper support of the fixed legs, a holding or supporting ring is provided inside with rollers that move on a prepared for this purpose annular outer track of the tower. Above this bracket and legs, the system remains as a bending-stressed tower part with previous scales and thus offers few opportunities to allow new, larger dimensions.

The document WO 2013/009454 A2 discloses a bracing for a fixed tower of a wind turbine of great height, in which the tethers are connected as far as possible to the tower, wherein an angle of 10 ° relative to the vertical tower axis is not exceeded for the tethers allowed to avoid a collision with the rotor blades in the lower position. The still remaining safety distance between the ends of the rotor blades and the tethers is low and in strong winds there is a risk of collision between the rotor blades and the tethers. But with this orientation, no possibility is yet created to make the towers for greater heights or with less material intensity.

Also, the telescopically enlarged tower according to the document WO 2005/028781 A2 receives on the extendable tower section a further bracing, remains comparable to the top section at the usual level of bending stress, as it is only at the lower guyed tower sections this is avoided.

The tower for a wind turbine according to DE 10 2010 037 706 A1 is directed to achieve the lowest possible flow resistance of the tower in several structural designs for the tower cross-section, also to reduce the Turmvorstau, so that the use of material is favorably influenced. However, despite the approaches to different solutions for arranging the rotating device of the tower at different heights, the overall structure of the tower always remains as a bending-prone tower and offers no new approaches to solutions. If wind turbines in previously used hub heights of up to 130 m were to be braced, wire ropes would be used. Even in the steel core design, these braces stretch by 2 ... 3% through the twisted wires in the strands and the strands in the rope despite the multiple pre-stretching done prior to installation.

For masts of greater heights, therefore, measures must be taken to compensate for these large rope expansions or largely avoided.

Thus, the publication DE 103 09 825 A1 discloses a wind turbine with a mast provided with wire ropes braces, which is designed to equip the guy additionally with controllable hydraulic damping devices. The description of the invention is directed solely to the damping devices, their integration into the guy system and their control. About details of the guying and their geometric arrangement such. B. their angle to the turret vertical or their connection to the mast are not specified in the description, but it is particularly noted that guyed masts are common in smaller installations. Solutions for bracing wind turbines of higher heights are not specified.

The object of the invention is to provide for the use of wind energy inland the towers of wind turbines in the megawatt range, a new tower structure to the prevailing at higher altitudes resources of the wind with economically advantageous scale, i. with low indicators of material usage and costs. This new tower structure includes both the structural design of the tower body and its bracing. The bracing is designed so that the wind and additional forces acting on the rotor are introduced into the foundation without great strain. Due to the selected material type, the special material quality and dimension occur according to the associated modulus of elasticity only minimal strains. Both conditions are achieved by

- The bending stress of the tower arising on previous towers from the wind power as a product of rotor force and hub height targeted in a couple of forces is divided from compressive stress and tensile stress both on fixed towers with rotating nacelle at hub height and with full warranty of rotation of the tower including its rotor and

- The guy elements are made in their total length of solid, high-strength rolled steel with end pieces forged on both sides and joined to achieve the required overall length as a complete guy from several bracing low elongation.

This creates two embodiments of the wind energy plant:

- The guyed fixed tower with the rotating nacelle hub, in which the braces are firmly connected to the tower, and

- The opposite the foundation and in the hub height fixed to the rotor rotatable tower, in which allow the bracing via a guying ring, the rotation of the tower.

For the embodiment of the fixed tower with rotating nacelle hub, a fixed guy ring is placed between two tower sections.

In the embodiment of the rotatable tower, a guy ring is arranged below the intersection of the tower vertical with the hub height, which receives all around the upper ends of the guy elements. This is due to its structural design on the horizontal and on the vertical PTFE (polytetrafluoroethylene)

- Sliding bearing of the ring, or at choice as a roller bearing slewing bearing, despite fixed Abspannelemente allow the rotation of the tower in the wind.

The arrangement of the guy ring in the tower vertical below the hub height does not allow for arbitrarily large angle bracing when using the principle "upwind" (windshield) to avoid collisions of the blade tips in the lowest position in elastic deformation by high wind speeds. The tensioned guy elements are arranged in a bracing angle of 13 °.

The elastic modulus of the material of the bracing is independent of their shape and type available. The considerable elongation of the wire rope, depending on the The design of the rope, which can not be eliminated even by repeated pre-stretching, is not to be used for the stable operation of the rotor at high altitude due to the great lengths of the braces present here. Damping devices despite bias in a complex manner would be necessary.

In the embodiment of the guy elements and connections according to the invention as solid high-tensile tension elements, additional elongations do not occur. By converting the previously common bending stress of the tower in a compressive stress of the tower from the rotor force of the wind and in a tensile stress of the guying a significant reduction in the use of material and thus the cost of the tower is achieved despite the increase in the hub height.

Further details and advantages of the subject invention will become apparent from the following description and the accompanying drawings, in which two preferred embodiments are shown. Show it:

Fig. 1 a fixed tower with bracing and guy elements according to the first embodiment to the maximum allowable height of 220 m according to the principle of the leeward rotor assembly (downwind principle) with rotating nacelle hub height-dependent on the rotor diameter used, in the lower of the 2 shows a rotatable tower with bracing and guy elements according to the second embodiment up to a maximum permissible height of 220 m in principle the leeward rotor arrangement (downwind principle) with directly mounted rotor, wherein the lower of the two figures the bracing is shown in plan view,

3 shows a rotatable tower in the embodiment of FIG. 2, but for very large hub heights and a possible service crane on the tower,

4 shows the guy ring in a fixed embodiment between two tower sections, wherein in the upper figure, the top view in section A - A and in the lower figure, the side view are shown, 5 shows the guy ring in plain bearing design for the guy elements, the side view being shown in the left-hand illustration and the plan view in the right-hand illustration being shown in section,

6 shows the guy ring in roller bearing design for the guy elements, wherein in the upper figure, the side view and in the lower figure, the plan view are each shown in section, and

Fig. 7 shows the formation of the guy elements and their hinged connections with each other in the upper four figures and the connection of the respective upper guy element with the guy ring of the tower according to the second embodiment in the lower illustration.

The two exemplary embodiments according to FIGS. 1 and 2 for each wind turbine tower essentially have in common a welded truss tower 2, 2 a, a rotor hub 15 equipped with rotor blades 16, a foundation 1 for the tower 2, 2 a bracing provided with six guy elements 4, and foundations 8 for lower attachment of the guy elements 4. Another common feature of both embodiments is the leeward rotor assembly (also referred to in the literature as downwind principle). The truss towers 2, 2a are screwed together from several sections, which are arranged in the tower vertical 2b. So that the rotor 13 can be placed in the wind, a rotary joint 10 or 21 and an azimuth drive is provided in each case. The rotary joint 22 is after the 1. Embodiment between the upper section of the tower 2 and the nacelle 21 and according to the second embodiment on the foundation 1 for receiving the lower segment of the tower 2a arranged. Thus, an essential difference between the two embodiments is that either only the nacelle 21 is rotatable relative to the tower or the entire tower 2a with its construction relative to the foundation 1 can perform a rotational movement 1 1. This has the consequence that between the fixed bracing according to the second embodiment and the rotatable tower 2a rotational movement compensation must be made possible.

The upper attachment of the guy with the tower 2 according to the first embodiment is shown in the drawing of FIG. 4. The guy ring 3e is a rectangular plate with circularly arranged recordings of Tensioning elements 4 fixedly disposed within the framework of the tower 2. The attachment points for the six guy elements 4 are designed such that the tower vertical 2b, the hub height 17 and the lines of action of the guy elements 4 intersect at a common point 14. As a result, the rotor force of the wind acts as compressive stress on the tower 2 and as tensile stresses on the guy elements 4.

In place of the rotary joint The upper attachment of the bracing with the tower 2a according to the second embodiment is shown in Figs. 2, 3, 5 and 6. The six guy elements 4 lead, as in the first embodiment, each from a fixed foundation 8 obliquely up to a, the tower 2a on the cylindrical part of an intermediate section surrounding Abspannring 3. This guy ring 3 allows the rotation of the entire tower 2a with the rotor 13 relative to the stationary arranged Abspannelementen 4. Such a Abspannring 3 may consist of a vertical and a horizontal PTFE bearings 3a, 3b or 6 of FIG. 6 of a rolling bearing 3 c of FIG. 5. Their arrangement on the cylindrical part of an intermediate section can be seen as details from the aforementioned drawings. The lower orientation points for the orientation of the guy elements 4, taking into account a certain bracing angle 9 to the tower vertical 2b, the solid foundations 8. The common upper landmark point is the intersection 14 of the guy elements 4 and the tower vertical 2b with the hub height17. The guy angle 9 of the guy elements 4 to the tower vertical 2b is 13 ° in the embodiment. With a smaller tightening angle 9, unfavorable static influences / conditions would arise, and a larger tightening angle 9 would lead to the danger of collision with the anchoring elements 4 as a function of the rigidity of the rotor blades 16.

10, on which the tower 2a is supported on the foundation 1, a roller slewing connection, a circular track with conical wheels, a ball track, a ball pin or even a fluid plate slideway can also be used. To generate the rotational movement of the entire tower 2a with the rotor 13 with respect to the foundation 1, the known azimuth drives are used. The rotor 13 (FIG. 2) is according to the second embodiment in FIG Difference to the first embodiment on the Fachwerkturm 2a secured against rotation and takes the rotor hub 15 with the rotor 13 on. At the lower end of the Fachwerkturmes 2a is a frame for receiving the machine house 12 with the torque transmission from the rotor 13 to the drive train and the electrical equipment. Since this torque transmission is not the subject of this invention, it will not be described in detail below.

In Fig. 3, a larger wind turbine is also shown according to the second embodiment. The latter is designed for high-altitude wind use, starting at 200 m above the site.

If, for special reasons of the location or the climate, there is a need to arrange a second guy ring 3 at a corresponding height of the tower 2a, then the corresponding number of additional guy elements 4, which are adapted in their length, must be integrated. The solid foundations 8 in such case must be adapted in shape and dimension to ensure the lower anchorage. This so-designed wind turbine is also distinguished by the constant provision of a suitable service crane 18, which is indispensable for such an order of magnitude of the hub height 17 and performance both for the structure and for the service to high economic cost for repeated rents and picking up suitable large lifting to avoid. In both embodiments, the rotational movement of the nacelle 21 or the tower 2a can be carried out unhindered in fixed guy elements 4. The guy elements 4 should stretch only minimally under load. Therefore, the use of wire ropes is out of the question. As material for the guy elements 4, that is to say also for each individual guy member 4a, rolled steel of the highest strength and in the corresponding dimension and design is provided for both exemplary embodiments. The upper end 6 of the guy element 4 is inserted in the second embodiment according to the lower figure of Fig. 7 from below into the guy ring 3 and blocked over the guy ring 3 by the fitting member 3d. According to the first embodiment, the guy elements 4 are connected in the same way to the non-rotatable guy ring 3e. The individual lengths of the bracing members 4a are connected to the connecting member 5 in either two-pin connection 20 or in one-piece connection 19th together. In the usual design of a one-off connection according to DIN 18800-1; 2008-1 1 the increase factor 1, 2 to consider. To reduce this influence, the special design of the link in the illustrated form is performed.

The length of the bracing members 4a and their connections offer the possibility of transporting a plurality of bracing members 4a stacked for common transport on pallets. To stabilize the vertical position of the tower 2 or 2a after assembly - not yet in operation - all bracing elements are advantageously biased to 30% of their rated operating load. Depending on the choice of one of the proven clamping methods and equipment, this is done either between two tendons 4a, at the lower fixed point of the foundation 8 or at the upper end of the guy element 4 on Entspannring 3e according to the first embodiment or on Abspannring 3 according to the second embodiment. The recommended tightening angle 9 leads to the exemplary embodiment of the lower fixed points in the foundation 8, which in their entirety are not outside the diameter of the rotor 13. The terrain between these foundations 8 can be cultivated or used except for a driveway and working space for service equipment for the machine house and tower foundation 1 agricultural. The recommended service crane 18, in particular when using high-altitude wind, will also be used for parts replacement (rotor blade after lightning strike), for work from the personnel basket and finally for dismantling after the end of use.

Reference numerals:

1 tower foundation

2 fixed welded truss, sheet metal, or hybrid tower 2a rotatable welded truss, sheet metal, or hybrid tower 2b tower vertical

3 guy ring with fixed guy elements 4 3a vertical PTFE bearing

3b horizontal PTFE bearing

3c rolling bearings

3d fitting link

3e fixed to the tower 2 non-rotatable guy ring. 4

anchoring element

4a bracing member

5 connecting member between two bracing members 4a

6 upper end of the guy element 4

8 foundations for the guy elements

9 Tension angle to the vertical 2b

10 Rotary connection between foundation 1 and tower 2a

1 1 Rotational movement of the tower 2a

12 engine house

13 rotor at the tower head (downwind)

14 Intersection hub height - Tower vertical 2b - Tension angle 9

15 rotor hub

16 rotor blade

17 hub height

18 service crane

19 one-sided connection of the bracing members 4a

20 two-section connection of the bracing members 4a

21 revolving gondola

22 Slewing connection between gondola 21 and tower 2

Claims

claims

1 . Wind turbine tower in welded sheet steel, trussed or prestressed hybrid construction, which is either firmly connected to the foundation (1) and at its upper end the nacelle (21) with the rotor 13 is rotatable azimuth or completely rotatable on the azimuth on the foundation (1 ) is arranged, and anchored in both embodiments by a plurality, preferably six guy elements (4), in the ground, characterized in that the tower vertical (2b), the hub height (17) and the lines of action of the guy elements (4) in a common Point (14) cut and thus from the rotor force of the wind on the tower (2, 2a) compressive stress and on the guy elements (4) tensile stresses and the Entspannelemente (4) in their total length necessary to minimize their elongation under increasing load of solid, made of high-strength rolled steel and double-forged end pieces, these end pieces having one or two-point connections (19, 20) be added by bolts to reach the required total length as a complete guy element (4) of several bracing members (4a).

2. Wind turbine tower according to claim 1, characterized in that the guy rings (3, 3e) on the circumference evenly distributed fasteners for the upper ends of the guy elements (6) and in the version with the tower (2) of the guy ring (3e) firmly connected to the tower (2) and in the embodiment with the azimuth rotatable tower (2a) of the guy ring (3) on the tower (2a) is horizontally rotatable and fixed in height.