ES1077139U - Tower for wind generator (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Wind generator tower, which is provided to mount a wind turbine (4) at its corresponding upper end and to obtain electric power based on the force of the wind, and said tower being mounted on an appropriate foundation foundation (8) and wherein the tower itself is formed by a cylindrical body based on modules (2) coupled successively to each other in height and provided with the lower part with reinforcements (6), is characterized in that each module (2) of the tower is formed by several panels (2 ') with a determined curvature, collaterally interengaged with each other monolithically, to form a cylindrical configuration in each module (2), with the particularity that the lower reinforcements (6) are constituted by radial abutments with a one-piece character at each one of the panels (2 ') forming each module (2) of the tower (1); it being further provided that both the radial and lower abutments (6) and the lower end of the tower (1) have protruding parts (7) for their embedding in the corresponding foundation foundation (8). (Machine-translation by Google Translate, not legally binding)

Description

  TOWER FOR WIND GENERATOR

OBJECT OF THE INVENTION

The present invention relates to a mixed tower of concrete and steel, for supporting wind generators.

The object of the invention is to achieve a reduction in the costs of manufacture, transport and assembly of the shaft, compared to existing solutions in the market, as well as facilitate its manufacture in the workshop and make the maximum use of the section and the material of which consists.

BACKGROUND OF THE INVENTION

The search for renewable energy sources has increased in recent years, due to the increasingly firm belief in the existing hypotheses about climate change and its relation to the production of carbon dioxide and greenhouse gases.

This search has promoted the emergence of new technologies that would allow the maximum amount of energy to be extracted from renewable energy sources such as sunlight and wind. Not only have new technologies appeared, but they are in a continuous process of improvement in order to increase energy production yields.

The electricity produced by wind turbines is based on the curve of the vertical wind profile, in which the wind speed is established based on the height and roughness of the terrain.

The wind turbine transforms a part of the energy that carries the volume of air that passes through the surface beaten by the blades, when it circulates at a speed above the threshold, below which, the blades do not move.

In the sector of wind power generation, there has been an important and constant development during the last years, increasing the maximum power of the wind turbines, reaching unthinkable powers less than 10 years ago. This increase in power is based on two fundamental principles of wind power generation, such as the scanning surface and the air velocity.

The vertical wind profile has a variation of parabolic slope, so that from a certain speed, the increase in wind speed with height is irrelevant. That is why, the dimensions of the blades and, consequently, the height of the wind turbine hubs, will not increase unlimitedly but that their roof has either been reached or is close to being reached, since an increase in the height means a significant increase in manufacturing, assembly and operation costs.

To date, the realization of steel shafts was common, due to their good fatigue behavior, their lightness and the great development of the industrial manufacturing, transportation and assembly process.

Most of the manufacturers make circular section and variable edge shafts with a truncated shape, with the maximum diameter at the base, since it is the area with the largest actions. These shafts are composed of several subsections of the same length, generally, which are assembled at their ends either with screws or by other fastening systems.

However, despite its correct operation, concrete solutions began to be studied due to the volatility of the steel market in past years and the increased demands of high-power wind turbine spindles.

The high volatility of the steel market during the years 2006 to 2008, caused significant disruptions to the manufacturers of shafts, either due to the variability of prices, upwards in most cases, or due to the delay in the delivery of material . This forced wind turbine manufacturers to consider the concrete solution for wind turbine shafts, not contemplated until then due to the relative difference in costs between the two solutions.

The need to raise wind turbine hubs above 80 meters, reaching 150 meters, markedly increased the magnitude of efforts, both static and dynamic, with their corresponding effects of fatigue and durability. These efforts are not suitably absorbed by the current solutions used in the lower height shafts, so the study and development of concrete shafts was forced.

The installation of wind turbines in shallow continental shelf areas, especially in the North Sea, also began, which also increased interest in concrete shafts due to durability due to saline attack of seawater.

With the increase of the quality standards required in the new constructions, the introduction of the prefabricated in the wind turbines sector was a matter of time, since the quality control to which the manufacturing of the precast concrete elements is subjected, is superior , in general, that which is carried out in the works executed "In Situ".

The use of precast concrete parts accelerates the assembly process, ensures an adequate geometry of the parts and has a high quality concrete. It also favors the production process, reducing costs and achieving industrialization of the production of shafts, complicated to achieve by manufacturing on site, in each location where the wind farm is located.

Analyzing existing patents worldwide, different solutions have been found whose differences with respect to the proposed model are explained below.

Starting with the patents of the Spanish Patent and Trademark Office, we find the patent ES 2317716 in the name of Gamesa Innovation and Technology S.L. in which a shaft composed of two sections is exposed. The upper section is composed of a tube that can be cylindrical or truncated and the lower section is a space lattice. The constituent material of both pieces is recommended to be steel. This solution differs markedly from that presented because the geometry is remarkably different.

The patent ES 2296531, also owned by Gamesa Innovation and Technology S.L, proposes a truncated conical solution for the shaft and made with precast concrete elements, joined on site. The shaft is divided into circumference segments joined together. This solution differs from the proposal since, although it is also made with precast concrete elements, the section of the shaft is conical and non-cylindrical, and does not carry the external reinforcements that the proposed shaft has. Nor do they coincide in the methods of joining the pieces.

The Vestas Wind Systems company owns the patent ES 2297130, which specifies the formation of shafts from steel sections. This patent differs markedly from the one presented, both in geometry and in the main material used.

The patent ES 2319709, owned by the company Prefabricaciones y Contratas S.A., proposes a novel shaft of precast concrete and metal structure, with a tripod base support, in which the possible legs are braced together. Again, the solution strongly disagrees with the proposal as it requires cross-type bracings of San Andres between the legs and throughout the section.

The patent ES 2246734 owned by Structural Concrete & Steel S.L., proposes the use of parts with horizontal and vertical internal stiffening ribs of about 30-35 m in length, which when joined together form the section of the truncated conical shaft. Again, this solution is limited to transferring the geometry of the trunk metal spindles to the concrete, with the problem that this change implies. No interactions are found with the proposed solution since the reinforcements are on the outer face.

From now on, some German patents for wind turbine shafts will be analyzed.

Patent DE 19832921, owned by W. Bernhardt, proposes a mixed concrete-steel solution, by means of a hollow section of steel, which is subsequently filled with concrete, forming a composite section Steel-Concrete-Steel. The correct connection between the materials is achieved with bolts inside the hole, attached to both walls, so that there is a solid connection between the three sections, since when the hole is concreted, the heads of the bolts are embedded in the solid . This solution, apart from having a truncated section, is far from both the materials and the geometry of the proposal presented.

Patent DE 29809541, owned by R. Beyer, also discloses a concrete shaft, consisting of sectors that are assembled, forming a truncated section, a solution that is markedly far from the proposed geometry.

Patent DE 102004048365, owned by O. Schneider, proposes a cylindrical section shaft with external reinforcements attached to the shaft punctually points with nickel-chrome pieces by means of screws. This typology is far from the proposal since the proposed stiffening ribs are integral to the ribbed panels that make up the shaft, without the need for intermediate joints.

Patent DE 202007003842, owned by Boehmert & Boehmert, proposes a pyramid-shaped shaft, composed of cylindrical sections and straight sections linked together, forming a complete and closed shaft. This solution again disagrees with the one proposed because it has a variable section and no stiffeners.

Patent DE 202008001606, owned by P.Wetzel, proposes a truncated pyramid shaft, with sharp edges, and formed by straight panels without ribs. This solution strongly disagrees with the proposal, in the geometry of the section and in the absence of external reinforcements.

From now on, some European patents for wind turbine shafts will be analyzed.

EP 1227204, owned by Ralf U. Hofmman, proposes a truncated spindle solution executed in situ, by means of climbing or sliding formwork. This solution differs from the proposal not only in the method of execution, but in the geometry of the section.

Patent EP 1767729, owned by Sika Technology, proposes a stem of a truncated section, in which each division has made a split type so that each section of shaft is composed of three segments joined by tongue and groove and with an inner filling. Again, the shaft is approached with a transposition of the metal solution to concrete, with the problem that the excessive amount of subsections originates in what refers to the joints. There is no great similarity between this patent and the proposed solution.

EP 2182209, owned by Martin Gluck, proposes a hybrid solution with the upper metal zone and the lower concrete zone, with a truncated and prestressed section seen on the inner face. This solution continues to extrapolate the truncated steel to concrete solution, adding the prestressing seen as a tie element between the sections. There are no great synergies with the proposed solution.

From now on, some Japanese patents of wind turbine shafts will be analyzed.

The IP 2000283019 patent proposes a solution of a cranial shaft, formed by superimposed concentric cranial caps, with shear keys in the support and with sleeve-type joints between the joining pieces. This solution continues with the truncated section and with the truncated tubes described in other previous patents, with the difference that the joints reflected in the drawing are considered insufficient and a great difference can be seen with respect to the presented model.

Patent IP2004011210, owned by Fuji Corporation, proposes a succession of cylinders of circular or polygonal section, and of ascending diameter from the head to the base, joined with tongue and groove and with longitudinal and circumferential prestressing. These cylinders will eventually be divided into vertical sectors. This patent takes the solution of cylindrical sections, in order to facilitate manufacturing, however, the lack of reinforcements requires a considerable diameter to be taken at the base, higher than estimated with the reinforcements in the model presented.

The IP2005180082 patent proposes a shaft with cylindrical section in several sections, its diameter being different in each section, with a maximum value in the embedment with the foundation and a minimum in the union with the gondola. It also has the use of a special piece, to make the transition from one diameter to another, and the connection between modules is done with prestressing seen from the inside of the shaft. Again, the detailed solution is based on the superimposed cylindrical rings to form each subsection of the shaft, and anticipates that the cylindrical section is a good solution to reduce costs, but nevertheless, it is markedly far from the solution recommended with radial reinforcements in the area lower.

The IP2005220715 patent proposes an initial solution at the base of the truncated conical section and a final section of the cylindrical section. Each of the sections divides them into cone or cylinder trunks, composed of subsections joined together by means of horizontal and vertical screwdriving, as if it were a metal joint. This solution differs markedly from the proposed geometry.

The IP2005248687 patent proposes a shaft solution built in situ, a solution markedly different from that recommended with precast concrete parts.

The IP2005330675 patent proposes a cylindrical shaft formed by superimposed sections and assembled by means of prestressing. In addition, how much with an energy absorption system in case of an earthquake, based on metal parts that absorb part of the earthquake energy by hysteresis. This solution considers that the cylindrical section is the solution to the problem but does not consider the reinforcements at the base of the recommended solution.

The IP2007046292 patent proposes a solution of a cranial shaft, consisting of one-piece cylindrical cylinders, in the upper zone, and cylinders composed of conical sectors, in the lower zone. The assembly between the sections is carried out with some tubes on hold, so that the section of the tubes in the upper part of the piece is greater than that of the lower part, constituting the joint by tongue and groove between the tubes. The sections are provided with an inner circumferential rib to which a circumferential prestress will also be supplemented. This solution, based on the tongue and groove joint between modules by means of the tubes, lacks reinforcement in the base and the section is helped by the joining tubes, to obtain greater rigidity, so that the differences with the recommended solution are large.

The IP2007120080 patent proposes a truncated pyramid shaft, since it declares polygonal section instead of cylindrical. The shaft length is divided into several pyramidal sections. Again the variable edge solution is used again, but this time with a polygonal section instead of a circular one, a patent that differs significantly in the geometry of the recommended shaft.

The IP2007120080 patent proposes a solution with straight pieces of trapezoidal section, whose assembly produces a polygonal section of constant edge along the shaft. The length of the shaft is divided into several cylinders which in turn are subdivided into several pieces forming a polygonal prism. The pieces that make up the cylinders into which the shaft is divided, are joined together, by metal rings located inside the shaft, equidistant along its geometry. This connection is made with screws. Two additional solutions are also proposed. The first one would be identical to the previous one, but disregarding one of every two pieces of trapezoidal section, forming an open shaft. The other solution contemplates the placement of these vertical pieces, radially, and joining these with the inner metal rings, again constituting an open section. We believe that the solution of the rings is insufficient to support the efforts that come from the gondola, not only because of the geometry of the metal part but also because of the fragility of the union with the screws. In addition, both alternative solutions differ significantly from the recommended solution, both in geometry and bearing capacity.

The IP2008101363 patent proposes a shaft solution divided into several prismatic sections, each of which is divided into several vertical panels. These panels will have a part of their armor in view, bars that would be joined together by executing the joint filling with a mortar and mechanical anchoring anchors.

This solution is composed of vertical panels, but these lack ribbed reinforcements as the recommended solution, in addition to having a joining method, which differs from the one presented.

The IP2002122066 patent proposes a cylindrical section shaft throughout the section, with radial reinforcements in the lower zone. This solution divides the shaft into several cylindrical prisms that are subsequently joined by longitudinal post-tensioning. In the lower part, "T" shaped reinforcements are placed, attached to the foundation by post-tensioning and attached to the shaft, with bolts.

This solution also adopts the cylindrical shaft as an optimal solution, providing it with external reinforcement pieces in the base that help transmit the loads to the foundation. The geometry differs from that recommended in this patent, because the reinforcements are external parts that are screwed to the shaft and are attached to the foundation with bolts, in contrast to the section formed by ribbed panels in one piece. It also differs in the way of performing the main section, which in one case is made with cylindrical prisms and in the proposal of this patent, is performed in several vertical segments.

From now on, some North American patents for wind turbine shafts will be analyzed.

US 7464512, proposes a metal shaft solution composed of several sectors that, when joined together, create the entire section. This proposal divides the shaft into several longitudinal sections, each of which is subdivided into several polygonal geometry caps. Each of these metal sectors, covers an angle of between 90 and 120 degrees and has a polygonal section with a fold at each end, in which the connection is made by screws with the adjacent pieces. Eventually reinforcements will be placed inside the shaft in order to stiffen the joints. Although it is not specified in the text, a tripod type geometry can be seen in the drawings in the base area, to bracing the shaft at mid-height.

This solution differs markedly from the proposal, since the section is made of steel and not of precast concrete. Nor does the method of stiffening the shaft coincide.

US patent 2009000227 proposes a mixed shaft, divided into three sections. The lower section is cylindrical and concrete, the intermediate section is cylindrical and the upper section is also made of steel but with a cranial section

This solution uses a truncated conical solution, different from that recommended and lacks reinforcements in the base.

US patent 2009031639 proposes a novel solution of shaft, with truncated pyramid section in the lower section and cylindrical section of steel or concrete, in the upper section. The lower section is divided into tubular sections, each of which is formed by a succession of straight and curved pieces, interwoven together, that form the entire section. These pieces are joined by circumferential prestressing.

The geometry of this solution differs markedly from the proposed proposal.

From now on, some international patents of wind turbine shafts will be analyzed.

WO 0201025 proposes a crankshaft concrete shaft with longitudinal prestressing, anchored in the foundation and made in situ.

This geometry differs from that recommended and is not formed by a succession of prefabricated pieces.

WO 0204766, proposes a precast concrete crankshaft shaft, formed by sections of identical height and variable edge, joined together by longitudinal prestressing.

This section, again because it is an imitation of the existing solutions in steel, but transferred to the concrete, with the problems involved. This geometry differs from that recommended because it lacks reinforcements in the base and has a variable section.

WO 03069099 proposes several solutions for the shaft, all of them prefabricated.

The first one consists of a truncated pyramid section shaft, consisting of longitudinal pieces of constant section and between one and several transverse breaks, which, when assembled, form a closed section. This sequence of sections, the result of the assembly, is placed keeping the paphos, so that the edges in the geometry are maintained throughout the entire shaft.

Another variant of the previous solution consists in breaking these edge alignments, placing the rotated sections at a certain angle, thus avoiding the formation of constant edges along the alignment.

This patent also indicates a cylindrical shaft solution, divided into vertical sections, each of which is divided into 8 cylinder sectors, assembled together. In order to avoid the appearance of weak points in the shaft, the creation of constant joints along the shaft is avoided, placing each section to the three-leg, avoiding the coincidence of the vertical joints in adjacent sections. In other drawings, the shaft solution formed by a succession of cylindrical sections with specific section reductions is considered, maintaining the same exploded view as in the constant cylindrical solution.

Although, this patent describes a multitude of solutions formed by panels that, when assembled, form a composite section, these panels do not have the ribs of the solution that is recommended.

WO 2007025947 patent proposes a shaft in situ, with concreting by pump with vertical upward flow. With this system, the different sections into which the shaft has been divided are successively concreted, causing the set parts to rise through the pressure of the concreting. In addition, it is essential to tighten the head of the built shaft, to avoid bending that could collapse the shaft during the concreting phase or elevation at each interface.

In this patent, a geometry in itself is not defined, but rather a method of making spindles for on-site wind turbines, which is clearly far from the recommended solution.

WO 20100.32075, proposes a mixed pyramid-shaped concrete-steel shaft. This solution creates an open shaft, in which the section takes the form of a tetrahedron, in which the rising edges are circular sectors of concrete and these are braced together, with a lattice in each of the planes that form the pyramid. In this way a lighter section is achieved, which takes advantage of the total edge of the section, but which is more complex in its assembly and design, since although the concrete pieces are all the same throughout the entire height of the shaft, the lattices are Variable edge from the base to the head.

The differences between this solution and the one recommended are notable, not only in the geometry but also in the composition of the materials used.

WO 2010044380, proposes different solutions that will be analyzed in detail.

The development of the patent begins, describing a solution of prismatic shaft with octagonal section and constant edge. This shaft thus defined, would be divided, longitudinally, into rings of a certain height, and in turn, each ring would consist of 4 "C" shaped caps joined with circumferential post-tensioning. The alternate rings would have nerve reinforcements on their outer face, and the union between all the rings, both ribbed and smooth, would be performed with longitudinal post-tensioning.

The next proposed solution consists of a cylindrical shaft, also divided into rings, but with a helical reinforcement on the entire outer face of the prefabricated, from the base to the head.

Other proposed solutions are similar to different patents set forth above, either by means of a truncated pyramid, a truncated cone and an original shaft with circular reinforcements of variable diameter, of doubtful structural utility.

Analyzing all these typologies exposed in the described patent, we did not find reasonable similarity with respect to the proposed proposal, since continuous stiffening reinforcements of the shaft are not described, in contact with the foundation.

DESCRIPTION OF THE INVENTION

The tower that has been recommended has been designed to solve the problems described above, based on a simple but highly effective solution.

More specifically, a first novelty presented by the tower of the invention is that the shaft of the invention is of a cylindrical configuration in all its height, whereby the manufacturing process is much simpler than when it is of a conical-conical configuration.

Another characteristic of novelty is that the tower materializes in concrete, with or without lightening, based on modules that are conveniently coupled to each other throughout the height of the tower, with the particularity that each module is formed by a series of sectors or parts that are collaterally assembled together to form the cylindrical ring, attachable to other analogs to form the tower.

In a lower section of the tower, monolithically bonded buttresses are provided for reinforcement of the base, with protruding parts that are embedded in the foundation base itself.

In this way, towers of great height can be achieved, without problems of vibrations or durability, allowing a much simpler manufacturing than when the tower is conical, and more importantly, it allows the manufacture in workshop of each and every one of the pieces that make up each module, then "in situ" to carry out the assembly of the pieces of each module and the vertical correlative union of the different modules to form what is the shaft of the tower, in whose part The corresponding wind turbine will be mounted above.

The pieces that constitute each module are considered as precast concrete panels, monolithically joined by means of active or passive steel, these panels or pieces presenting a constant radius so that in each case a cylindrical module is formed.

Based on the above, it is possible to manufacture a tower with a minimum number of formwork, based precisely on the constitution of precast concrete panels and, if necessary, prestressed.

Finally, say that the buttresses provided in the lower section of the tower and that logically complete its structural scheme with its monolithic connection to the uniform cylinder of the shaft, will have a variable edge, depending on its height, being its section preferably rectangular, without ruling out another section, such as trapezoidal for greater heights.

DESCRIPTION OF THE DRAWINGS

To complement the description that will then be made and in order to help a better understanding of the features of the invention, in accordance with a preferred example of practical implementation thereof, a set of drawings is accompanied as an integral part of said description. where the following has been represented by way of illustration and not limitation:

Figure 1 shows an elevation view of the tower made in accordance with the object of the invention, with a wind generator provided on top of it.

Figure 2.- Shows a sectional view corresponding to the cutting line (A-A) represented in Figure 1.

Figure 3.- Shows another sectional view, in this case corresponding to the cutting line (B-B) of the same figure 1.

Figure 4.- Shows an enlarged detail, in a sectioned perspective, of the lower part of the tower equipped with the corresponding buttresses, highlighting the configuration of the detail of a panel.

PREFERRED EMBODIMENT OF THE INVENTION

As can be seen in the aforementioned figures, the tower (1) of the invention is characterized in that it has a cylindrical configuration in all its height, and is formed by a plurality of modules (2) that conveniently couple together in a monolithic manner in vertical to form the shaft of the column or tower itself, so that each module (2) is determined by a plurality of pieces elongated vertically, which are panels, always made of concrete, and which have an appropriate curvature to form between them a cylindrical configuration for each module (2), seeing in figures 2, 3 and 4, the corresponding module (2) that is determined in each case by several panels or parts (2�), which correspond to a sector of the cylinder and that they are conveniently coupled to each other collaterally by passive or active steel, to be monolithically joined, and in each case form the corresponding module (2), joining in turn the different modules vertically, also mono lithically, by means of active or passive steel, to form the shaft of the tower (1) with a completely cylindrical configuration, which in its upper part has a neck (3) on which the corresponding wind turbine (4) is mounted, in whose arms are arranged the respective blades (5), as is conventional.

The shaft of the tower (1) has in its lower part a series of buttresses (6) that are part of each of the pieces or panels (2�) that form the modules (2), all in such a way that the joining between panels (2�) and of course buttresses (6) is carried out monolithically with active or passive steel means, being able to manufacture in the workshop and carry out the assembly "in situ", with the special feature that the module ( 2) The lower part of the tower, like the buttresses (6), has recessed projections (7) in the corresponding foundation base (8).

As is evident, in the different monolithic unions between the modules (2) that form the tower (1) and the union of the different panels or pieces (2�) that form each module (2), it will be made with the corresponding joints achieve a completely waterproof structure, resistant and practical in its functionality.

Claims (1)

1�.- Tower for wind generator, which being provided to mount a wind turbine at its corresponding upper end and obtain electrical energy based on the force of the wind, and said tower being mounted on an appropriate foundation base, is characterized in that it is constituted by a cylindrical body based on modules successively coupled to each other in height and reinforced the lower part or section thereof with radial buttresses with protruding parts, as well as the lower end of the tower, for recessing in the corresponding base of foundation. 2�.- Tower for wind generator, according to claim 1, characterized in that the cylindrical body of the tower is formed by a succession of modules successively monolithically coupled to each other in height, and each module determined by several panels with a determined curvature, collaterally interconnected each other, also monolithically, to form a cylindrical configuration in each module. 3.- Tower for wind generator, according to previous claims, characterized in that the radial reinforcement buttresses are monolithically connected to each of the pieces or panels that form each module of the tower. 4�.- Tower for wind generator, according to claim 3, characterized in that the buttresses are of rectangular section and even trapezoidal for high heights. 5�.- Tower for wind generator, according to previous claims, characterized in that the union of the different pieces or panels of each module and the union between them of the modules, carried out monolithically, is carried out by means of active or passive steel. 6�.- Tower for wind generator, according to previous claims, 5 characterized in that the different pieces or panels of each module and the corresponding reinforcement buttresses, and consequently the entire shaft of the tower, are made of concrete with or without lightening.