SE2151522A1

SE2151522A1 - A wind turbine

Info

Publication number: SE2151522A1
Application number: SE2151522A
Authority: SE
Inventors: Pascual Eneko Sanz; De La Rúa Ion Arocena
Original assignee: Nabrawind Tech S L
Priority date: 2020-12-28
Filing date: 2021-12-13
Publication date: 2022-06-29
Also published as: ES1276849U; AU2021273593A1; CN216767641U; ES1276849Y; DK202100120U3

Abstract

A wind turbine, the wind turbine includes a tubular tower (3), a nacelle (1), a rotor and its blades (2), the tower ends in three legs (5) and each of said legs (5) is anchored on rocky soil with an anchored-in-rock foundation, it is anchored on conventional soil with a pile foundation, it is anchored in a competent non-rocky soil with a gravitational foundation and it is anchored on clayey or swampy soil with a gravitational foundation reinforced with piles. The advantages are the savings of establishing a tower ending with three legs. The foundations presented herein reduce the amount of concrete required by more than 80%.

Description

A WIND TURBINE DESCRIPTION Field of invention The present invention falls within the wind turbine field, more specifically, in a novel windturbine the tower of which ending with three legs and which is also anchored to theground by means of a characteristic anchoring system depending on the type of existingsoil.

BackgroundGround-based wind turbines are anchored to the ground by means of a footing. As the height of the wind turbines increases, the size of the footing increases proportionally andconsequently the amount of concrete used. The footings are made by making a circularhole in the ground, a reinforcement with metal bars is provided and concrete is poureduntil the entire hole is filled. On this base the wind turbine is set up, placing the tubulartower parts one on top of the other, to finally topping it off with the nacelle and the blades.The works to make a footing are influenced by the type of soil. Establishing a reinforcedconcrete footing in a rocky area is more difficult than establishing it in a terrain with a lotof soil and little rock. ln order to use as little concrete as possible, it is presented the novel wind turbineconstituting the inventive subject matter, using a specific and advantageous type ofanchoring system for each type of soil.

DescriptionWind turbines consist of a tower, regardless of the type of tower used, anchored to the ground and supporting the nacelle, rotor and blades.

The proposed wind turbine has a tubular tower whose lower part is formed by a tripod.ln this way, the base of the wind turbine has three legs and each leg has itscorresponding anchoring system to the ground. lf the diameter at the base of the towerof a conventional wind turbine is 4.5 m in the case of the novel wind turbine, the base isreduced to three legs of 1 m in diameter each. This reduces the amount of reinforcedconcrete used as footing.

Depending on the type of soil on which the wind turbine of the invention is to be established, a type of anchoring system is used:1 - Firstly, hardest floors. Rocky soils that have between 100 and 200 Megapascals.An anchored-in-rock foundation is used.

- Secondly, rock soils of lower hardness, in which a pile foundation is used whichrequires less time and less quantity of concrete than conventional or gravitationalfoundations.

- Thirdly, competent non-rocky soils, where a gravitational foundation is used.

- And finally, poor soils and without consistency. They can be swampy or floodedterrain. A gravitational foundation with piles is used to provide stability. ln sum, the present invention provides a wind turbine, the wind turbine includes a tubulartower, a nacelle, a rotor and its blades, the tower ends in three legs and each of saidlegs is anchored on rocky soil with an anchored-in-rock foundation, it is anchored onconventional soil with a pile foundation, it is anchored in a competent non-rocky soil witha gravitational foundation and it is anchored on clayey or swampy soil with a gravitationalfoundation reinforced with piles.

The advantages are the savings of establishing a tower ending with three legs, whichentails three anchoring systems compared to a single anchoring system used byconventional wind turbines. The volume of concrete for the footing of a 150 m towerheight is 600 m3. The foundations presented herein reduce the amount of concreterequired by more than 80%.

Brief description of the drawings Below, it is very briefly described a series of drawings which will help us to betterunderstand the invention and that expressly relate to an embodiment of said inventionthat is presented as a non-limiting example thereof.

Figure 1 represents the entire wind turbine object of the invention.

Figure 2 shows the anchoring system in rocky soils.

Figure 3 shows the anchoring system by means of a pile foundation.

Figure 4 shows the anchoring system by means a gravitational foundation.

Figure 5 shows a last anchoring system by means of a gravitational foundation with piles.

Detailed descriptionAs shown in figure 1, the wind turbine of the invention consists of a nacelle (1) with its corresponding rotor and blades (2) and a tubular tower (3) terminated in a transition piece2 (4), which has three legs (5) and sits on the ground (6). The legs (5) are spaced fromeach other at a distance much greater than their diameter, in the present embodimentthey are 18 m from each other. The ratio between diameter and distance between legs(5) is approximately one to twenty. Depending on the type of soil in question, theanchoring system of the legs (5) will have some characteristics or others.

Figure 2 shows the anchoring system in a rocky soil. The legs (5) of the wind turbine arelocked on a cube footing (7) from which a plurality of bars (8) extend and which areanchored to the rock. ln the detail shown in the figure, and according to a specificpractical embodiment for a wind turbine of a certain height, weight and power, nine bars(8) are included for each of the three footings (7). The footing (7) has inside connectionelements (9) with the leg (5) and the bars (8) extending downwards deepening in therocky terrain.

As shown in Figure 3, the anchoring system in this embodiment is a pile foundation.When the soil is not hard enough to introduce the anchoring bars into the rock, it isproceeded with a pile anchoring system (10). A deep hole is made, 20 or 30 m deep,which is subsequently filled with metal rods (11) forming the reinforcement and thatextend circumferentially along the walls of the hole. The connection elements (9') areplaced on the surface with each leg (5) of the wind turbine, which are also attached tothe metal reinforcement(11). Finally, concrete (12) is poured into the hole and left to set.Figure 4 shows the type of anchoring system used in competent non-rocky soils. ln thistype of terrain, the conventional gravitational foundation is used, that is, the stability ofthe foundation is given by the dead weight of the conical footing (13) and the weight ofthe structure that it supports on top. The footing (13) includes inside connection elements(9") with its corresponding leg (5). The footing (13) is formed by a structure of metal barsarranged in a conical shape (not shown in the figure) on which concrete is poured andleft to set.

Figure 5 shows the type of anchoring system used in clayey or swampy soils. ln this typeof terrain, the gravitational foundation is used where, to give the foundation greaterconsistency, a plurality of small piles (14) extend from the base of the footing (13)deepening in the terrain and bringing stability to the ensemble. On the three footings (13)which support the wind turbine gravel (15) is poured to smooth the ground.

Claims

1. - A wind turbine, the wind turbine includes a tubular tower (3), a nacelle (1), arotor and its blades (2), characterized in that the tower ends in three legs (5) and eachof said legs (5) is anchored on rocky soil with an anchored-in-rock foundation, it isanchored on conventional soil with a pile foundation, it is anchored in a competent non-rocky soil with a gravitational foundation and it is anchored on clayey or swampy soil witha gravitational foundation reinforced with piles.

2. - A wind turbine according to claim 1, wherein the three legs (5) are widelyseparated from each other, in a ratio between diameter and spacing between legs (5) of one to twenty.

3. - A wind turbine according to claim 1, wherein the anchored-in-rock foundationhas a cube footing (7) for each leg (5), connection elements (9) between the footing (7)and the leg (5) and a plurality of bars (8) extending downwardly from the footing (7).

4. - A wind turbine according to claim 1, where the pile foundation is made withpiles (10) of great length reinforced with metal (11) and filled with concrete (12), it alsohas connection elements (9') protruding from the surface of the pile (1 O).

5. - A wind turbine according to claim 1, wherein the gravitational foundation ismade with a conical footing (13) that includes inside connection elements (9") with the leg (5).

6. - A wind turbine according to claim 1, wherein the gravitational foundation ismade with a conical footing (13) that includes inside connection elements (9") with theleg (5) and from whose base a plurality of small piles (14) that go deep into the groundextend.