TOWER FOR A WIND POWER PLANT OR A MOBILE PHONE TRANSMITTING AND RECEIVING STATION

Description

[0001] The invention relates to a tower for a wind turbine or a mobile communication transmitter / receiver with at least one section having polygonally arranged walls, wherein the walls are made of a wood-based material, wherein two walls are connected to each other in a corner of the polygon in the form of a vertical joint with each of them having a side surface.

[0002] A wind turbine is a device for generating electrical energy. It consists of a foundation, a tower erected on the foundation, and a nacelle mounted on the tower. The drive unit for energy generation, connected to rotor blades, is located on the nacelle. Such wind turbines are well-known and familiar to those skilled in the art. The nacelle is mounted on the tower. At its end, the nacelle is equipped with a rotor with a horizontal or vertical axis of rotation, which is coupled to a generator. Three-bladed rotors are commonly used because they ensure relatively smooth operation. These types of wind turbines are highly developed with regard to the efficiency with which wind power can be utilized. Such towers are known, for example, from DE 10 2015 014 648 A1.

[0003] The height of wind turbine towers varies. Generally speaking, energy yield correlates with the tower height, with towers reaching well over 100 meters and even over 150 meters. Therefore, there is a clear economic relationship between construction costs and energy production, with experience showing that construction costs increase disproportionately with the turbine's height.

[0004] The tower's design is geared towards the static loads acting on the tower by the nacelle and the dynamic loads acting due to the rotation of the rotor blades and the nacelle's ability to move depending on the wind direction.

[0005] Mobile communication transmitters and receivers – known as base stations – are the nodes of a mobile network. Each base station provides reception to a narrowly defined area – the cell. Such installations are familiar to those skilled in the art. They are located in elevated positions, particularly on masts or towers.

[0006] Well-known towers are constructed from steel rings or concrete elements. From an economic perspective, it is desirable to maximize the tower's height for cost-effective construction. This applies, for example, to wind turbines, because the yield of a wind turbine depends on the rotor's hub height, and yield increases with height. At the same time, the demands placed on the tower's structural integrity and materials, as well as the material costs, increase due to the tower's greater height. Wall thicknesses increase, thereby raising the tower's construction costs.

[0007] The bases of the known towers are either polygons or ring-shaped circular segments. Polygonal towers made of individual concrete segments are known from WO 2003 / 069099 A. These are connected with cement or with prestressing tendons. When connected with prestressing tendons, the joints are compressed by prestressing.

[0008] Furthermore, it is known to erect polygonal towers made of wood (DE 10 2007 006 652 A1). Polygonal towers made of individual segments of a wood-based material are known from DE 10 2009 048 936 A1. The wall sections are trapezoidal and connected to each other using fasteners, particularly adhesives. It has been shown that towers for wind turbines can be manufactured from wood, allowing for cost-effective, rapid, and material-saving construction. It has proven particularly advantageous to manufacture these towers on-site from individual components, which are directly connected to the adjacent elements using fasteners. One embodiment also provides for the erection of a falsework structure inside the tower, which itself does not contribute to the transfer of the static or dynamic loads of the finished tower (DE 10 2009 048 936 A1).A coating has proven advantageous as protection against environmental influences acting on the surface, especially moisture (DE 10 2009 017 586 A1).

[0009] The joining of the vertical joints still needs improvement.

[0010] Therefore, the object of the invention is to improve vertical butt joints, particularly with regard to shear transfer between elements connected via the joint.

[0011] The problem is solved by the fact that the side surface of a wall has at least one connecting element in the vertical joint, that the at least one connecting element is suitable for transmitting shear force in the vertical joint, that the at least one connecting element has at least one projection (prong) and at least one recess (valley), that the at least one projection and the at least one recess are arranged such that the at least one projection of one wall engages in the at least one recess of the other wall in the vertical joint when the walls are assembled, and that at least one step is provided between a projection and a recess, wherein the projections of two connecting elements of two walls are arranged one above the other in the vertical joint when the walls are assembled.

[0012] In this registration, "level(s)" is synonymous with "jump(s)."

[0013] It has surprisingly turned out that this makes a particularly efficient shear transfer possible in the vertical joints between the walls.

[0014] A further aspect of the invention provides that at least two steps are provided between a projection and a recess. It has proven particularly advantageous that the efficiency for transmitting the shear forces of the corners in the vertical joints depends on the number k of steps between the prongs and the valleys. This number is particularly preferably k / (k+1).

[0015] A further aspect of the invention provides that the length of a step in the vertical joint is half the length of a projection or recess. This advantageously influences the efficiency of the shear force transmission.

[0016] Another teaching of the invention provides that the number of connecting elements is evenly distributed over the length of the vertical joint on the side wall.

[0017] Another teaching of the invention provides that the wood material is laminated veneer lumber.

[0018] A further aspect of the invention provides that at least one wall of the section has a rectangular shape. Such a shape essentially has no waste.

[0019] A further aspect of the invention provides that at least one wall of the section has the shape of a triangle. It is advantageous that the triangle is an isosceles triangle. This makes it possible to minimize waste.

[0020] A further aspect of the invention provides that the walls are composed of wall sections. It is advantageous that the wall sections are rectangular, trapezoidal, and / or triangular. Furthermore, it is advantageous that the wall sections are assembled into segments that, when stacked, form the tower. This also reduces the waste from offcuts over the entire length of the section.

[0021] Another teaching of the invention provides that the wall sections are connected to each other to form segments and walls using an adhesive, either directly or via additional connecting elements, preferably wooden elements, placed between them.

[0022] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. These show: Fig. 1 a schematic spatial representation of a wind turbine with a tower according to the invention, Fig. 2 a schematic spatial representation of an embodiment of a tower according to the invention, and Fig. 3 a top view Fig. 2 . Fig. 4 a spatial view of a segment of a tower according to the invention, Fig. 5 a top view fig. 4 , Fig. 6 an enlarged view of Fig. 4 , Fig. 7 a side view to Fig. 4 , Fig. 8 a side view of a first trapezoidal wall element Fig. 4 , Fig. 9 a side view of a first rectangular wall element Fig. 4 , and Fig. 10 an enlarged view of Fig. 9 .

[0023] Fig. 1 Figure 1 shows a spatial view of a wind turbine 100 with a tower 10, the underside of which 160 is mounted on a foundation 150. An adapter 110 is provided on its upper side 170, on which a nacelle 120 is rotatably mounted, the nacelle having a rotor 140 with a hub 130.

[0024] The tower 10 has a cross-section in the form of a polygon 20 with n vertices 12 at its lower end 13. It is composed of individual walls 14, which are arranged polygonally according to the cross-section 20. The walls consist of a wood-based material, for example cross-laminated timber, laminated veneer lumber, or the like.

[0025] In the Fig. 1 In the embodiment shown, the tower 10 has a section 11. Alternatively, several sections can be provided, at least one of which is designed according to the invention. At its upper end 15, the polygon 20 of the cross-section of the tower 10 or of the section 11 preferably has n / 2 vertices.

[0026] In this embodiment, the tower 10 has different walls 14. Rectangular walls 14a and triangular walls 14b, preferably designed as isosceles triangles, alternate. This makes it possible to halve the number n of vertices 12 from the lower end 13 to the upper end 15, so that the polygon 20 has only n / 2 vertices at the upper end.

[0027] Alternatively, the halving of the corners can be omitted, so that the side walls 14b are not triangular but trapezoidal.

[0028] In the exemplary embodiment according to Fig. 2 and Fig. 3 The lower end of the polygon has 13 vertices, while the upper end has only four. However, it is advantageous to have more vertices, for example, 13 vertices at the lower end and 15 vertices at the upper end. Alternatively, the number of vertices can again be halved.

[0029] For transport and manufacturing reasons, it is advantageous to divide the walls 14, 14a, 14b into wall sections 16, which, for example, have a length of 12.5 m, 15 m, or 20 m, and to assemble the walls 14, 14a, 14b from these wall sections 16 on site. For this purpose, it is advantageous, for example, to join the wall sections 16 into horizontal segments 17 via corner joints 18 to join the vertical joints 27 in the corners 12 between the walls 14, 14a, 14b or 16, 16a, 16b, 16c. The segments 17 are then arranged one above the other, thus forming section 11 or tower 10.

[0030] The wall sections 16 are provided as rectangular wall sections 16a to form the walls 14a. Furthermore, trapezoidal wall sections 16b and, if necessary, triangular wall sections 16c, preferably isosceles, are provided to construct the triangular walls 14b.

[0031] Walls 14, 14a, 14b and wall sections 16, 16a, 16b, 16c can be connected to each other at their horizontal joints using fasteners. These fasteners can be adhesive or clamping elements such as anchor rods or threaded rods. If adhesive is used, additional fasteners, such as wooden wedges, metal plates, anchors, or similar components, can be employed.

[0032] The tower wall 14, 14a, 14b is the load-bearing element of the tower 100 structure. It is responsible for transferring all loads to the foundation 150. For example, in a wind turbine, the largest component of the load is the resulting normal force due to the bending moment from wind exposure and turbine operation. The diameter is largest at the tower base due to the maximum bending moment and tapers upwards towards the nacelle 120 to reduce load and ensure blade clearance for the rotors 140.

[0033] In Fig. 4 bis Fig. 10 For example, a wooden tower 10 according to the invention is considered in a further embodiment, for example with a height of 100 m.

[0034] Due to transport simplifications in standard trucks, the maximum length per segment 17 can be set at 12.50 m. This results in a total of eight equally long segments 17 for the wooden tower 10, which are arranged one above the other. During on-site assembly, these are to be joined on the ground, for example, to form octagonal segments 17 (see Fig. 4 , 5 ) are composed of a corresponding number of plate-shaped wall components 16, 16a, 16b, 16c.

[0035] The assembled segments 17 are lifted to their destination in tower 10, for example, using a heavy-duty crane.

[0036] For transport reasons, the panel width of the individual wall components may be limited to a maximum width of 2.42 m. The exact width varies depending on segment 17 and its installation height in tower 10.

[0037] A single wall element 16b of a segment 17 is in Fig. 8 shown. This is trapezoidal in shape and thus tapers towards the top.

[0038] A single wall element 16a of a segment 17 is in Fig. 9 This is shown. It is rectangular and therefore tapers to a constant width towards the top.

[0039] In the Fig. 8 und 9 The illustration shows both pockets 21 and threaded rods 22 of the horizontal joints 23, as well as vertical joints 27 of the wall elements 16a, 16b consisting of tenons 24, steps 28 and valleys 29 and pockets 25 with threaded rods 26.

[0040] The horizontal joints 23, with which the individual polygonal circular segments 16 are joined one above the other, are constructed using pre-stressed threaded rods 22. For this purpose, pockets 22 are milled into the inside of the tower walls 16 of the upper and lower wall elements 16 at the manufacturing plant, for example, to a depth of 90% of the wall thickness. The threaded rods 22 can be inserted around the outer wall via a circular arrangement (not shown). Precisely fitting load distribution plates (not shown), for example made of steel, are also inserted into the pockets to ensure better force transmission into the wood material, such as laminated veneer lumber. To accommodate the statically required number of threaded rods 22 without excessively weakening the cross-section, two staggered layers of pockets 21 are selected. The required number is determined by the structural analysis.

[0041] A wall element 16a is shown as an example in Fig. 10 The prongs 24, steps 28 and valleys 29 of the vertical buttresses 27 are arranged so that they are compatible with those of wall element 16b.

[0042] The arrangement of the vertical threaded rods 26 must be checked in detail. These serve only to pull the wall elements 16a, 16b together during assembly. They do not meet any static requirements.

[0043] The vertical joints 27 primarily serve to transmit the shear forces resulting from horizontal stress. For this reason, the vertical wall joints of the vertical joints 27 are designed in a tine-like shape according to the invention, in order to ideally absorb the resulting shear forces. The length I of the tines 24, the length t of the valleys 29, and the length s of the steps 28 result from the selected number of tines 24 over the total length of the wall elements 16a, 16b.

[0044] The prongs 24 must be arranged alternately for the wall elements 16a and 16b so that they interlock in the corresponding valleys 29. During milling, the angle of inclination of the tower and, if necessary, minimal play for easier assembly must be taken into account.

[0045] The maximum width b of the tines 24, steps 28 and valleys 29 is determined once for a wall thickness and accordingly converted to a changed wall thickness.

[0046] For example, a wall thickness of 30 cm can result in a width b of 6 cm.

[0047] The tines 24 are preferably designed with steps 28 to achieve a more favorable bearing length. According to the invention, the number of steps is greater than or equal to 2. The greater the load in the vertical impacts, the higher the number of steps 28 should be.

[0048] It has proven geometrically advantageous that the length I of the prongs 24 corresponds to the length t of the valleys 29, and that the length s of the steps is in turn half this length. In this way, the prongs later fit particularly well into the valleys.

[0049] The following relationships are preferred: The axle length is calculated as follows: Achslänge = Fugenlänge des Vertikalstoβes / 2 * Anzahl Zinken The tine length I, or valley length t, is calculated as follows: l = t = Achslänge / 2 The length of each step is calculated as follows: s = Achslänge / 4

[0050] The vertical joints 27 are also formed by means of threaded rods 26 in milled pockets 25. These serve purely structural purposes and are used to tighten the joints. They are not used for the transmission of forces.

[0051] Each pocket 25 is fitted with a threaded rod 26, for example with a diameter of 20 mm and a length of 30 cm, and a steel plate for load distribution. The insertion length per wall is 10 cm. An additional 5 cm is required in each pocket for screwing on the nut, as well as for the washer and the load distribution plate.

[0052] The threaded rods 26 are particularly necessary when the assembled segments 17 are lifted by the crane, as additional vertical dead loads 26 must be transferred via the threaded rods at this point. Once the segments 17 are bolted together in the horizontal joints 23, the structure stiffens itself further.

[0053] Furthermore, it has preferably been found that the efficiency for transmitting the shear forces of the corners in the vertical joints 27 depends on the number k of steps 28 between prongs 24 and valleys 29. This is particularly preferably k / (k+1).

Claims

1. Tower (10) for a wind turbine (100) or a transmitting and receiving system for mobile communications, having at least one section with polygonally arranged walls (14, 14a, 14b), wherein the walls (14, 14a, 14b) are formed from a wood material, wherein in each case two walls (14, 14a, 14b) in a corner (12) of the polygon are connected to one another, by way of in each case one side surface, in the form of a vertical joint (27), characterized in that the side surface of a wall (14, 14a, 14b) in the vertical joint (27) has at least one connecting element, in that the at least one connecting element is suitable for transmitting shear forces in the vertical joint (27), in that the at least one connecting element has at least one projection (24) and at least one depression (29), in that the at least one projection and the at least one depression are arranged in such a way that the at least one projection (24) of a wall (14, 14a, 14b) engages into the at least one depression (29) of the other wall (14, 14a, 14b) in the assembled state of the walls (14, 14a, 14b) in the vertical joint (27), and in that at least one step is provided between a projection (24) and a depression (29), wherein the projections (24) of two connecting means of two walls (14, 14a, 14b), in the assembled state of the walls (14, 14a, 14b), are arranged one above the other in the vertical joint (27).

2. Tower according to Claim 1, characterized in that at least two steps (28) are provided between a projection (24) and a depression (29).

3. Tower according to Claim 1 or 2, characterized in that the length of a step (28) in the vertical joint (27) is half the length of a projection (24) or of a depression (29).

4. Tower according to one of Claims 1 to 3, characterized in that the number of connecting means is distributed uniformly over the length of the vertical joint (27) on the side wall.

5. Tower according to one of Claims 1 to 4, characterized in that the wood material is laminated wood veneer.

6. Tower according to one of Claims 1 to 5, characterized in that at least one wall (14, 14a, 14b) of the section has a rectangular shape.

7. Tower according to one of Claims 1 to 6, characterized in that at least one wall (14, 14a, 14b) of the section has the shape of a triangle or trapezium.

8. Tower according to one of Claims 1 to 7, characterized in that the walls (14, 14a, 14b) are made up of wall sections (16, 16a, 16b, 16c).

9. Tower according to one of Claims 1 to 8, characterized in that the wall sections (16, 16a, 16b, 16c) are rectangular, trapeziform and / or triangular.

10. Tower according to one of Claims 1 to 9, characterized in that the wall sections (16, 16a, 16b, 16c) are assembled to form segments (17) that, arranged one above the other, form the tower (10).