Conical or cylindrical ring segment, prestressed concrete tower and method for manufacturing a ring segment

Abstract

A conical or cylindrical ring segment (1), particularly for a tower (10) of a wind turbine, is designed as a precast concrete element, wherein the ring segment (1) is manufactured in a high-precision formwork such that dimensional deviations of the contact surfaces of the ring segments (1) are within a tolerance range of ± 0.5 mm, preferably ± 0.3 mm. A prestressed concrete tower (4) comprises ring segments (1) assembled to form rings (2), with several rings (2) positioned one on top of the other, and horizontal joints (9) between the rings (2) being dry-jointed. A method for manufacturing a ring segment (1) as a precast concrete element provides that the ring segment (1) is manufactured in a high-precision formwork such that dimensional deviations of the contact surfaces of the ring segments (1) are within a tolerance range of ± 0.5 mm, preferably ± 0.3 mm.

Description

[0001] The invention relates to a conical or cylindrical ring segment, in particular for a tower of a wind turbine, which is designed as a precast concrete part.

[0002] Wind turbines have a tower, which can be constructed of reinforced concrete, for example. The tower consists of ring segments constructed as precast concrete elements. This allows for weather-independent prefabrication of the ring segments. The prefabricated ring segments are then transported to the installation site and assembled there to form a prestressed concrete tower. The ring segments are first assembled into rings and stacked on top of each other. In conventional towers, the conical rings are connected to each other using mortar or a grout. Mechanical fasteners such as screw connections and the like can also be used.

[0003] In a hybrid tower, the lower section consists of a prestressed concrete tower with a reinforced concrete structure, onto which a transition piece is mounted. The upper section of the hybrid tower is formed by a tubular steel tower. The tubular steel tower houses the turbine technology, including the nacelle, generator, hub, rotor blades, etc.

[0004] The cylindrical or conical ring segments used for reinforced concrete towers are manufactured in a formwork at the factory. However, the problem can arise that the dimensional accuracy of the contact surfaces of the ring segments is unsatisfactory. In these cases, the surface of the formed-out ring segment must be subsequently machined using a mechanical process, such as grinding or milling. If the ring segment is undersized, additional material must be applied to the surface of the ring segment. However, such reworking is time-consuming and correspondingly expensive. Therefore, there is a need for a ring segment that can be manufactured with the required precision yet cost-effectively.

[0005] The invention is therefore based on the object of providing a conical or cylindrical ring segment which can be manufactured precisely and yet cost-effectively with regard to the dimensions of its contact surfaces.

[0006] To solve this problem, a ring segment having the features of claim 1 is provided.

[0007] The invention is based on the idea of ​​producing the ring segment in a high-precision formwork so that dimensional deviations of the contact surfaces of the ring segments lie within a comparatively narrow tolerance range of ± 0.5 mm, preferably ± 0.3 mm. In this case, no reworking is required after stripping, resulting in considerable savings in working time and costs. The accuracy of the dimensions of the contact surfaces achieved by the invention cannot be achieved with conventional formwork for ring segments for wind turbines. The use of exceptionally precise formwork ensures that the dimensions of the contact surfaces of the ring segments lie within a particularly narrow tolerance range. The high precision of the ring segments also ensures that recesses in the ring segments form precise channels for tendons such as strands, so that the tendons can be easily pulled in.

[0008] The invention thus has the advantage that no reworking is required for a ring segment. The surface of a removed ring segment does not need to be removed by a mechanical process, nor does it require material to be applied to the surface of the ring segment or a ring formed from ring segments after stripping.

[0009] The invention also relates to a prestressed concrete tower, in particular for a hybrid tower of a wind turbine. The prestressed concrete tower according to the invention is characterized in that ring segments are assembled to form rings, with several rings positioned one on top of the other, and horizontal joints between the rings are constructed dry without filler. By simply stacking the individual rings on top of each other, additional work steps such as the insertion or application of mortar or filler into the horizontal joints are eliminated. Since mortar and filler can only be used within a specific temperature range, the assembly of a prestressed concrete tower at an installation site can be carried out regardless of the weather. This avoids seasonal restrictions and delays in the assembly of a hybrid tower, which could otherwise occur, for example, in regions with long cold periods.

[0010] Similarly, in the prestressed concrete tower according to the invention, vertical joints between the ring segments can be constructed dry, without filler. Providing dry vertical joints offers the same advantages as dry horizontal joints. Overall, these measures can shorten the work required at the installation site, thus reducing the dependence of the assembly on weather conditions.

[0011] In the prestressed concrete tower according to the invention, it can optionally be provided that the ring segments have form-fitting connecting elements of oppositely formed configuration on their vertical sides. These connecting elements facilitate the positioning and assembly of the rings consisting of the ring segments.

[0012] A further development of the invention provides that the prestressed concrete tower has prestressed tendons that penetrate the ring segments. The tendons are anchored, on the one hand, to a foundation of the prestressed concrete tower and, on the other hand, to a transition piece arranged on the uppermost ring. The rings of the reinforced concrete tower are thus connected and tensioned to each other only by the tendons.

[0013] In addition, the invention relates to a method for producing a conical or cylindrical ring segment as a precast concrete part, which is produced in a high-precision formwork, so that the dimensional deviations of the contact surfaces of the ring segments are within a tolerance range of ± 0.5 mm, preferably ± 0.3 mm.

[0014] The invention is explained below using an exemplary embodiment with reference to the drawings. The drawings are schematic representations and show: Fig. 1 a ring of a prestressed concrete tower consisting of three conical ring segments according to the invention; Fig. 2 a perspective view of a prestressed concrete tower according to the invention; and Fig. 3 a tower according to the invention, which is designed as a hybrid tower.

[0015] Fig. 1 shows a ring 2 consisting of three conical ring segments 1. The individual ring segments 1 are precast concrete elements provided with reinforcement and manufactured in a high-precision formwork. Depending on the height of the prestressed concrete tower, a ring 2 can have three to four ring segments. The rings 2 in the lower area of ​​a prestressed concrete tower are formed from four ring segments 1, while in the upper area each ring 2 has three ring segments 1. Accordingly, a ring 2 extends either 90° or 120° in the circumferential direction. Each ring 2 has recesses 3 distributed around the circumference and running longitudinally, which are designed as through-openings for the tendons. The recesses 3 run parallel to the outer and inner sides of the ring segments 1, depending on the conicity of the geometry of the ring segments 1, which can be conical or cylindrical.

[0016] In Fig. 1 shows that two recesses are missing on opposite sides of ring 2. This area is required for door recesses; no tendons are installed at these locations.

[0017] Since ring segment 1 is manufactured in a high-precision formwork, no reworking is required after striking. This ensures that dimensional deviations of the contact surfaces of the ring segments are within a tolerance range of ± 0.5 mm, preferably ± 0.3 mm. This offers the advantage that the ring segments can be positioned dry, without bonding or filling compound, and tensioned using tendons. The assembly of a prestressed concrete tower or a hybrid tower can thus be carried out largely independent of weather conditions.

[0018] Due to the extremely good dimensional accuracy, it is not necessary to subsequently process a stripped ring segment 1 by grinding, milling, or a similar mechanical process. Since this process inevitably does not produce undersized ring segments 1, the subsequent application of material in the form of filler to the surface is unnecessary.

[0019] Fig. Figure 2 shows a prestressed concrete tower 4, which consists of rings 2 positioned on top of one another, which in this embodiment are conical. A prestressed concrete tower can also have cylindrical rings; for example, the uppermost rings below the transition piece can be cylindrical. Vertical joints 5 of successive rings 2 are arranged offset from one another according to the segmentation of the respective ring 2. At the lower end of the prestressed concrete tower 4 is a schematically illustrated foundation 6, in which the tendons are anchored. The Fig. 2, the end anchorage of the tendons (not shown in detail) is designed in a trumpet shape in this embodiment. The lowest ring 2 has a door recess 7.

[0020] At the upper end of the prestressed concrete tower 4 there is a transition piece 8 to which the tendons are anchored with their upper ends.

[0021] Horizontal joints 9 between the rings 2 are constructed using dry, unbonded methods and without filler. The rings 2 are thus held together solely by the prestressed tendons. In this embodiment, the vertical joints 5 between the ring segments are also constructed using dry, unbonded methods.

[0022] Fig. Figure 3 shows a tower 10 designed as a hybrid tower, comprising the foundation 6, the prestressed concrete tower 4, and the transition piece 8, on which a tubular steel tower 11 is located. A machine housing 12, containing a generator, is arranged on the tubular steel tower 11. A generator shaft has a hub 13 to which rotor blades 14 are attached. List of reference symbols 1 ring segment 2 rings 3 recess 4 prestressed concrete tower 5 vertical joint 6 Foundation 7 Door recess 8 Transition piece 9 horizontal joint 10 Hybrid Tower 11 steel tube tower 12 machine housings 13 Hub 14 rotor blades

Claims

[1] Conical or cylindrical ring segment (1), in particular for a tower (10) of a wind turbine, which is designed as a prefabricated concrete part, characterized by that the ring segment (1) is manufactured in a high-precision formwork, so that dimensional deviations of the contact surfaces of the ring segments (1) are within a tolerance range of ± 0.5 mm, preferably ± 0.3 mm. [2] Conical or cylindrical ring segment according to claim 1, wherein neither the surface of the removed ring segment (1) is removed, nor is material applied to the surface. [3] Prestressed concrete tower (4), comprising ring segments (1) according to claim 1 or 2, which are assembled to form rings (2), wherein a plurality of rings (2) are positioned one on top of the other, wherein horizontal joints (9) between the rings (2) are made dry without filling compound. [4] Prestressed concrete tower according to claim 3, wherein vertical joints (5) between the ring segments (1) are executed dry without filling compound. [5] Prestressed concrete tower according to claim 4, wherein the ring segments (1) have oppositely formed form-fitting connecting elements on their vertical sides. [6] Prestressed concrete tower according to one of claims 3 to 5, wherein prestressed tendons passing through the ring segments (1) are anchored on the one hand to a foundation (6) of the prestressed concrete tower (4) and on the other hand to a transition piece (8) arranged on the uppermost ring (2). [7] Method for producing a conical or cylindrical ring segment (1) as a precast concrete part, characterized by that the ring segment (1) is manufactured in a high-precision formwork, so that dimensional deviations of the contact surfaces of the ring segments (1) are within a tolerance range of ± 0.5 mm, preferably ± 0.3 mm.

Images