Foundation, wind turbine having same, and method and use for producing same

Abstract

The invention relates to a foundation (1) of a wind turbine (100), having a foundation part (3) which is made of concrete (F) strengthened by way of a reinforcement (10) and has an upper-side inclination (a) which slopes downwards in the outward direction. It is proposed that a flow block (9) is arranged within the foundation part (3) and is designed to prevent a flow of the concrete (F) in the radial direction.

Description

[0001] Foundation, wind turbine with the same, as well as method and use for the production of the same

[0002] The present invention relates to a foundation for a wind turbine, comprising a foundation part, preferably a foundation slab, made of reinforced concrete, in particular fresh concrete, and having an outwardly sloping top surface. Foundations of the type described above are generally known. They are used to firmly anchor the wind turbine or its tower in the ground.

[0003] It is generally possible to assemble the foundations from several prefabricated components that are produced remotely from the construction site and transported to the site. However, in many installation locations, it has proven practical to manufacture the foundation component from fresh concrete, which is mixed and transported on site or at a nearby concrete plant.

[0004] The trend towards more powerful, larger wind turbines on the one hand and the desire to leave as little concrete as possible in the ground on the other hand give rise to the need to achieve increasingly efficient anchoring of the wind turbine in the ground, with corresponding requirements for the foundation.

[0005] The larger the wind turbine and the larger the external dimensions of the foundation section—for example, the outer diameter in the case of rotationally symmetrical components—the more concrete volume is generally required. The goal is to ensure the best possible anchoring of the wind turbine in the ground while minimizing the concrete volume as much as possible.

[0006] There are known attempts in the art to improve the effectiveness of the foundation relative to the required concrete input, i.e., to reduce the relative concrete input by increasing the inclination of the foundation section, i.e., the inclination of the surface of the foundation section sloping outward from the base area. According to the invention, a high or increased inclination is defined as an inclination of 12° or more.

[0007] Processing the concrete for foundation sections with such an increased gradient is significantly more difficult. Due to its fluid state, the concrete tends to flow radially outwards towards the outer formwork when concreting the foundation section, and it is therefore very labor-intensive to even create the desired increased gradient. To ensure the high gradient, the state of the art has necessitated mixing concrete with a very stiff consistency, i.e. a low slump. The required high rigidity of the concrete, in turn, results in increased processing effort, particularly when spreading and compacting the concrete and when pumping the concrete into the formwork, which complicates the production of the foundation section overall.

[0008] The invention was therefore based on the object of providing a foundation that overcomes the disadvantages described above as far as possible. In particular, the invention was based on the object of improving a foundation of the type described above so that even increased inclinations can be achieved economically without compromising the quality of the foundation component.

[0009] The invention achieves the above-mentioned object by designing the foundation with the features of claim 1. In particular, the foundation comprises a flow barrier arranged within the region of the foundation part in which the upper slope is located and designed to prevent the concrete from flowing radially. The invention is based on the finding that the natural tendency of the concrete to spread and distribute radially within the outer formwork due to gravity can be deliberately impeded by flow barriers within the foundation part.The more the flowability of the concrete is hindered in the radial direction, especially outwards, the more likely it is that the concrete will build up, especially in the radially inner areas of the formwork, in front of the flow barrier, whereby the upper slope of the concrete in the sloping area of ​​the foundation part is already at least partially established in a natural way.

[0010] In preferred embodiments, the foundation part is a foundation plate of the foundation, and / or a reinforcing rib of a rib foundation, and / or a section of a cross foundation.

[0011] The work that is then required to bring the foundation part to the desired inclination on its outer surface can be carried out much more time-efficiently and with less manual effort than with the state of the art.

[0012] Compared to the state of the art, the flow barrier allows slopes well above 12° to be created using a concrete with significantly lower viscosity than the state of the art. Concrete with a slump flow of F3 to F4 and / or a slump flow of S3 to S4 according to DIN EN 206-1 is preferably used.

[0013] The foundation part preferably has a base region, to which a projecting region with the upper, outwardly sloping incline is connected radially outwards, wherein the flow barrier is arranged within the projecting region.

[0014] The invention is advantageously further developed in that the inclination is in a range of 12° or more, more preferably in a range of 12° to 45°, even more preferably in a range of 12° to 18°, and particularly preferably in a range of 12° to 16°.

[0015] Alternatively or additionally, according to the invention, the reinforcement preferably has an upper slope that runs at substantially the same angle as the slope of the foundation section. Deviations of + / - 2° are considered substantially equal. Implementing the upper slope of the reinforcement at the same slope as the desired slope facilitates the creation of the final contour of the foundation section.

[0016] In a further preferred embodiment, the flow barrier has at least one ring which is arranged circumferentially within the reinforcement. The ring can be formed in one piece or in multiple parts and have a plurality of barrier elements arranged along a partial circle, wherein the barrier elements can be arranged at a distance from one another, can be arranged abutting one another, and / or can be arranged overlapping. The ring therefore does not have to have a mathematically strict circular shape, but can also have a circular, for example polygonal, shape. In other words, if the ring is formed in multiple parts, the individual elements of the ring preferably lie approximately on the same partial circle, so that the flow barrier impedes flow movement in all circumferential directions of the foundation part.

[0017] In a further preferred embodiment, the foundation part has a central axis, and the flow barrier is aligned concentrically with the central axis. The central axis of the foundation part preferably corresponds to the central axis of the wind turbine tower to be arranged on the foundation part.

[0018] In a further preferred embodiment, the flow barrier is connected to the reinforcement, wherein the reinforcement preferably exhibits a vertical shear force movement, and the flow barrier is arranged in the region of the vertical shear movement. Anchoring the flow barrier to the reinforcement facilitates the pouring of concrete into the reinforcement area within the formwork, and unintentional relative movement of the flow barrier to the reinforcement is prevented. The vertical shear reinforcement is suitable for connecting the flow barrier because it is already present in the structural design of the reinforcement, so that according to this aspect, no additional structural elements need to be introduced to anchor the flow barrier in the reinforcement. The installation of structural vertical reinforcement as an attachment aid for the flow barrier is also possible and preferred.

[0019] In a further preferred embodiment, the reinforcement has an upper main reinforcement, and the flow barrier extends downwards below the upper main reinforcement, preferably directly from the upper main reinforcement.

[0020] In a further preferred embodiment, the reinforcement has a lower main reinforcement, and the flow barrier extends up to the lower main reinforcement, preferably without being attached to the lower main reinforcement, or above the lower main reinforcement, where the flow barrier has a predetermined distance from the lower main reinforcement, preferably a distance of 5 cm or more, particularly preferably 20 cm to 40 cm. In a preferred embodiment, the foundation part has an outer wall with a height in the region of the incline, wherein the height h of the outer wall is equal to or greater than the predetermined distance I from the lower main reinforcement.

[0021] In another preferred embodiment, the flow barrier is interspersed with a plurality of radial, concrete-permeable recesses, such as holes and / or gaps. The recesses serve to better bond the flow barrier to the concrete. They prevent the formation of vertical joints that could otherwise occur along the flow barrier during setting.

[0022] In a further preferred embodiment, the flow barrier is formed from one or more grid or perforated bodies, preferably from plastic or sheet metal, more preferably from expanded metal, particularly preferably from ribbed expanded metal.

[0023] In a further preferred embodiment, the ring is a first ring, and the foundation part further comprises one or more further rings, wherein preferably one, several or all of the further rings are formed according to the at least one ring of the foundation according to one of the preferred embodiments described above.

[0024] In a further preferred embodiment, the base region has an outer base wall, and an (inner) ring of the flow barrier is arranged at a radial distance of 0 cm to 100 cm around the outer base wall. Alternatively or additionally, the flow barrier preferably comprises three or more rings, which are preferably arranged at equal distances from one another or with distances from one another that increase radially outwards; and / or wherein an inner ring has a height in the direction of the central axis in a range from 40 cm to 80 cm, preferably 55 cm to 65 cm, and the further rings each have a height in the direction of the central axis in a range from 15 to 40 cm, preferably 25 cm to 35 cm; and / or wherein the distances between the rings are selected such that the upper edge of a ring is in each case arranged at the height of a lower edge of a radially inner adjacent ring.

[0025] The invention was described above in a first aspect with reference to a foundation. In a second aspect, the invention further relates to a method for producing a foundation of a wind turbine, in particular a foundation according to one of the preferred embodiments described above, with a foundation part that has reinforcement and has an upper, outwardly sloping incline.

[0026] The method solves the problem described above by comprising the following steps:

[0027] - producing and / or providing reinforcement at an installation site for a wind turbine, wherein the reinforcement, which is preferably designed as a reinforcement cage, has a flow barrier,

[0028] - Manufacture and / or provide formwork around the reinforcement, and

[0029] - Concreting of the foundation part by placing concrete into the formwork so that the reinforcement is embedded in the concrete, whereby the flow barrier prevents the concrete from spreading radially.

[0030] With regard to the method, the invention utilizes the same advantages and considerations as the foundation according to the first aspect. Preferred embodiments of the foundation are also preferred embodiments of the method, and vice versa, which is why, to avoid repetition, reference is made to the above explanations.

[0031] In the method according to the invention, the foundation part is preferably designed according to one of the preferred embodiments of the first aspect described above.

[0032] In the method according to the invention, the concrete is preferably poured in layers, each with a height of 40 cm or less, preferably with a height of 30 cm or less, particularly preferably 25 cm or less. This ensures good spreading and compaction of the concrete and gradual setting with a homogeneous overall structure of the foundation section.

[0033] In a further preferred embodiment, the concrete used in the method according to the invention has a slump class of F3 to F4 and / or a slump flow class of S3 to S4. Slump and slump flow are understood according to the invention to be the consistency classes according to DIN EN 206-1. This reduces the use of personnel and equipment during concreting despite steep inclines. In a further aspect, the invention further relates to a wind turbine with a tower that is attached to a foundation. The invention achieves the underlying object with regard to this wind turbine in that the foundation is designed according to one of the preferred embodiments of the first aspect described above.

[0034] In this regard, the wind turbine utilizes the same considerations as the foundation according to the first aspect. Preferred embodiments of the foundation of the first aspect are also preferred embodiments of the wind turbine, and vice versa, which is why reference is made to the above explanations to avoid repetition.

[0035] In yet another aspect, the invention relates to the use of at least one ring, which is provided circumferentially in a reinforcement, for producing a foundation of a wind turbine, in particular a foundation according to one of the above-described preferred embodiments of the first aspect, and / or in a method according to one of the above-described preferred embodiments of the second aspect, wherein the foundation has a foundation plate which is formed from concrete reinforced by means of the reinforcement and has an upper-side, outwardly sloping inclination.

[0036] The use solves the problem described above in that at least one ring forms a flow barrier for the concrete in the radial direction.

[0037] The use utilizes the same advantages and considerations as the foundation and method of the aspects described above. The preferred embodiments of the first two aspects are also preferred embodiments of the use of the third aspect, and vice versa, which is why reference is made to the above explanations to avoid repetition.

[0038] The invention is described in more detail below with reference to the accompanying figures, which show a preferred embodiment.

[0039] Fig. 1 a wind turbine,

[0040] Fig. 2 shows a foundation for the wind turbine according to Fig. 1 in a schematic cross-sectional view, Fig. 3 shows a plan view of the foundation part according to Fig. 2,

[0041] Fig. 4 is a detailed view, schematically, in cross-section, of the foundation according to Figures 2 and 3, and

[0042] Fig. 5 shows a schematic process flow according to a preferred embodiment.

[0043] Fig. 1 shows a schematic, three-dimensional view of a wind turbine 100. The wind turbine 100 has a tower 102 and a nacelle 104 on the tower 102. The tower 102 can consist of tower segments arranged next to one another. An aerodynamic rotor 106 with three rotor blades 108 and a spinner 110 is arranged on the nacelle 104. During operation of the wind turbine 100, the aerodynamic rotor 106 is set into rotation by the wind and thus also rotates an electrodynamic rotor or rotor of a generator, which is directly or indirectly coupled to the aerodynamic rotor 106. The generator is arranged in the nacelle 104 and generates electrical energy.

[0044] The tower 102 is anchored in the ground 200 by means of a foundation, which will be discussed in more detail in the following sections 2 to 4.

[0045] The foundation 1 comprises a foundation part 3, in the present example, a foundation slab, which has a base region 5 in the region of its central axis L, to which a protruding region 7 adjoins radially outside. In a foundation slab, the protruding region 7 is referred to as the spur region. In the protruding region 7, the foundation part 3 has an upper, outwardly sloping inclination a, which in the preferred embodiment is in the range of 12° or more. In a foundation slab, this inclination is also referred to as the spur inclination.

[0046] In Fig. 3, which shows the foundation 1 from above, a flow barrier 9 is shown, which in the present embodiment consists of a number of rings 9a, 9b, and 9c. In principle, the flow barrier 9 could also be implemented with just one ring, for example, ring 9a.

[0047] One, several, or all of the rings 9a, 9b, 9c are penetrated by a plurality of through-openings 11. The flow barrier 9 is arranged concentrically to the center axis L. When using multiple rings 9a, 9b, 9c, as shown here, adjacent rings 9a, 9b and 9b, 9c are spaced apart from one another in the radial direction due to their different diameters, with the radial distance n, r2 increasing outwardly between adjacent rings 9a, 9b and 9b, 9c.

[0048] Fig. 4 shows the area 7 of the foundation 1 in more detail. Within a formwork 300, a reinforcement 10 of the foundation 1 is arranged, which has an upper main reinforcement 13 and a lower main reinforcement 15. Between the upper main reinforcement 13 and the lower main reinforcement 15, a vertical shear reinforcement 14 consisting of a plurality of vertical structural elements is formed.

[0049] In the areas 12a, 12b, 12c, one of the rings 9a, 9b, 9c is connected, preferably fastened, to the vertical shear reinforcement 14. The reinforcement 10 has an upper inclination ß, the angle of which to the horizontal preferably corresponds to the angle of the inclination α, thus, in the illustrated embodiment, being, for example, 12° or more.

[0050] The rings 9a, 9b, 9c of the flow barrier 9 have a dual function within the reinforcement 10 of the foundation 1. On the other hand, they serve to prevent the expansion of the concrete F in the radial direction during concreting, as shown schematically in Fig. 4.

[0051] If concrete is poured into the formwork 300 from above, for example in the inner area of ​​the reinforcement 10 on the left in Fig. 4, the concrete can flow along the arrows Pia, Pib, Pic in the lower area of ​​the reinforcement 10 along the lower main reinforcement 15 over the entire radial width of the foundation 1.

[0052] However, since the rings 9a, 9b, 9c do not extend all the way to the lower main reinforcement 15, but maintain a distance I from the lower main reinforcement 15, the flow barrier function of the rings 9a, 9b, 9c only begins once a filling height F of the concrete within the formwork 300 is reached that exceeds the value of the distance I. I is preferably in a range of 5 cm to 45 cm, for example, approximately in a range of around 30 cm. The foundation part 3 has a height h on its outer circumference that corresponds at least to the distance I.

[0053] In alternative embodiments, the rings can extend directly above the main reinforcement, although they preferably remain unconnected to the lower main reinforcement. Once this fill level is reached, the poured concrete F can no longer spread freely in the radial direction within the formwork 300, but is at least restricted, if not prevented, in its radial spread, as shown by arrow P2. The recesses provided in the rings 9a, 9b, 9c impede the passage of the concrete to such an extent that the creation of high inclinations a of 12° or more, in particular of 15° or more, is significantly easier compared to the prior art, even if a comparatively thin concrete, for example with a slump class F3 or F4, and / or a slump-flow class S3 or S4 according to DIN EN 206-1, is used during concreting.

[0054] The use of the thinner concrete also ensures a good connection of the flow barrier 9 within the foundation 1, and the recesses 11 improve the anchoring of the flow barrier in the concrete compared to closed-pore rings without recesses. The recesses 11 also potentially serve as ventilation openings during backfilling.

[0055] In a preferred embodiment, the foundation according to the invention is manufactured using the following method, which is illustrated by way of example in Fig. 5. In a first step 401, the reinforcement 10 is manufactured and / or provided at an erection site for the wind turbine 100, wherein the reinforcement 10 is preferably designed as a reinforcement cage according to Fig. 4. According to the invention, the reinforcement 10 has a flow barrier 9.

[0056] In a next step 403, a formwork 300 is provided or manufactured around the reinforcement 10. The order of steps 401 and 403 can also be reversed.

[0057] Once the formwork and reinforcement have been prepared, the next step 405 involves concreting the foundation section 3 by pouring concrete F into the formwork 300. The reinforcement 10 is at least partially, and preferably completely, enclosed in the concrete F, with the flow barrier 9 impeding the radial expansion of the concrete F. It may be expedient to begin the concreting process radially inward in the base area of ​​the foundation 1 and then work outward. In principle, however, the flow barriers also allow work in other directions.

[0058] Thus, in the method according to the invention, the foundation 1 is preferably formed according to one of the preferred embodiments described above. In a preferred variant of the method, the concreting step takes place in several stages, with the concrete F being poured in sections with a height of 40 cm or less, preferably with a height of 30 cm or less, particularly preferably with a height of 25 cm or less per concreting pass. The concrete F used preferably has a slump class F3 or F4, and / or a slump-flow class S3 or S4, in each case in accordance with DIN EN 206-1.

[0059] In summary, the use of one or more rings 9a, 9b, 9c within the reinforcement 10 for producing the foundation 1 of the wind turbine 100, as described above, offers the significant advantages of faster production because a significantly thinner concrete can be used compared to the prior art, so that higher inclinations can be provided with comparatively reduced effort.

[0060]

[0061] 1 foundation

[0062] 3 Foundation part, especially foundation slab

[0063] 5 Base area

[0064] 7 protruding area, especially spur area

[0065] 9 Flow barrier

[0066] 9a, 9b, 9c Rings

[0067] 10 Reinforcement

[0068] 11 through openings

[0069] 12a, 12b, 12c area

[0070] 13 Main reinforcement, top

[0071] 14 Shear reinforcement, vertical

[0072] 15 Main reinforcement, bottom

[0073] 100 wind turbines

[0074] 102 Tower

[0075] 104 gondolas

[0076] 106 Rotor

[0077] 108 rotor blades

[0078] 110 spinners

[0079] 200 soil

[0080] 300 formwork

[0081] 400 procedures

[0082] 401 Process step

[0083] 403 Process step

[0084] 405 Process step

[0085] L center axis

[0086] F Concrete distance

[0087] Pia, Plb, Plc arrow

[0088] P2Arrow n, r2Radial distance a Inclination, protruding area, especially spur area ß Top-side inclination, reinforcement

Claims

1. Foundation (1) of a wind turbine (100), with a foundation slab (3) which is formed from concrete (F) reinforced by means of a reinforcement (10) and has an upper, outwardly sloping incline (a), characterized in that a flow barrier (9) is arranged within the foundation part (3) and is designed to prevent the concrete (F) from flowing in the radial direction.

2. Foundation according to claim 1, wherein the foundation part (3) has a base region (5) to which a projecting region (7) with the upper, outwardly sloping inclination (a) is connected radially outwards, wherein the flow barrier (9) is arranged within the projecting region (7).

3. Foundation (1) according to claim 1 or 2, wherein the inclination (a) is in a range of 12° or more, more preferably in a range of 12° to 45°, even more preferably in a range of 12° to 18°, particularly preferably in a range of 12° to 16°, and / or wherein the reinforcement (10) has an upper side inclination (ß) which is substantially equal to the inclination (a) of the foundation part (3).

4. Foundation (1) according to one of the preceding claims, wherein the flow barrier (9) has at least one ring (9a, 9b, 9c) which is arranged circumferentially within the reinforcement (10).

5. Foundation (1) according to one of the preceding claims, wherein the foundation part (3) has a central axis (L), and the flow barrier (9) is aligned concentrically to the central axis (L).

6. Foundation (1) according to one of the preceding claims, wherein the flow barrier (9) is connected to the reinforcement (10), wherein preferably the reinforcement (10) has a vertical shear reinforcement (11), and the flow barrier (9) is arranged in the region of the vertical shear reinforcement (11).

7. Foundation (1) according to one of the preceding claims, wherein the reinforcement (10) has an upper main reinforcement (13), and the flow barrier (9) extends downwards below the upper main reinforcement (13), preferably directly from the upper main reinforcement (13).

8. Foundation (1) according to one of the preceding claims, wherein the reinforcement (10) has a lower main reinforcement (15), and the flow barrier (9) extends up to the lower main reinforcement without being attached to the lower main reinforcement, or extends above the lower main reinforcement (15), wherein the flow barrier (9) has a predetermined distance (I) to the lower main reinforcement (15), preferably a distance of 5 cm or more, particularly preferably 20 cm to 40 cm.

9. Foundation according to claim 8, wherein the foundation part has an outer wall with a height (h) in the region of the inclination, the height (h) of the outer wall being equal to or greater than the predetermined distance (I) to the lower main reinforcement (15).

10. Foundation (1) according to one of the preceding claims, wherein the flow barrier (9) is interspersed with a plurality of radial, concrete-permeable recesses, such as holes and / or gaps, wherein the flow barrier (9) is preferably formed from one or more grid or perforated bodies, preferably from plastic or from sheet metal, more preferably expanded metal, particularly preferably from ribbed expanded metal. 11 . Foundation (1) according to one of claims 4 to 10, wherein the ring (9a, 9b, 9c) is a first ring (9a), and the foundation part (3) further comprises one or more further rings (9b, 9c), wherein preferably one, several or all of the further rings (9b, 9c) are designed according to the at least one ring (9a, 9b, 9c) of the foundation (1) of one of the preceding claims.

12. Foundation (1) according to claim 11, wherein the base region has a base outer wall, and a ring (9a) of the flow barrier (9) is arranged at a radial distance of 0 cm to 100 cm around the base outer wall; and / or wherein the flow barrier comprises three or more rings (9a, 9b, 9c) which are arranged at equal distances (n, r2) from one another or with distances (n, r2) increasing radially outwards; and / or wherein an inner ring (9a) has a height in the direction of the central axis (L) in a range from 40 cm to 80 cm, preferably 55 cm to 65 cm, and the further rings each have a height in the direction of the central axis (L) in a range from 15 to 40 cm, preferably 25 to 35 cm; and / or wherein the distances between the rings are selected such that the upper edge of a ring is arranged at the height of a lower edge of a radially inwardly adjacent ring.

13. Wind turbine (100) with a tower (102) which is fastened to a foundation (1), characterized in that the foundation is designed according to one of the preceding claims.

14. Method (400) for producing a foundation (1) of a wind turbine (100), in particular a foundation (1) according to one of the preceding claims, with a foundation part (3) which has a reinforcement (10) and has an upper, outwardly sloping inclination (a), comprising the steps: - (401) producing and / or providing a reinforcement (10) at an installation site for a wind turbine (100), wherein the reinforcement (10), which is preferably designed as a reinforcement cage, has a flow barrier (9), - (403) producing and / or providing a formwork (300) around the reinforcement (10), and - (405) Concreting the foundation part (3) by introducing concrete (F) into the formwork (300) so that the reinforcement (10) is embedded in the concrete (F), the flow barrier (9) hindering the radial expansion of the concrete (F).

15. The method according to claim 14, wherein the concrete (F) is concreted in layers, each with a height of 40 cm or less, preferably each with a height of 30 cm or less, more preferably 25 cm or less.

16. Method according to one of claims 14 or 15, wherein the concrete (F) has the slump class F3 or F4, and / or the slump flow class S3 or S4.

17. Use of at least one ring which is provided circumferentially in a reinforcement (10) for producing a foundation of a wind turbine (100), in particular according to one of claims 1 to 12 and / or in a method according to one of claims 14 to 16, wherein the foundation (1) has a foundation plate (3) which is formed from concrete (F) reinforced by means of the reinforcement (10) and has an upper, outwardly sloping inclination (a), wherein the at least one ring forms a flow barrier (9) for the concrete (F) in the radial direction.

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