Patent Application
20240401570
The present invention relates to a method for installing and mounting towers made of concrete, preferably with a frustoconical section. The method allows the number of crane configurations used during said installation or mounting to be optimized, thereby reducing associated execution times and costs, or constructing towers with a larger height without increasing the number of crane configurations required. The invention also relates to a tower made of concrete installed and mounted by the aforementioned method.
In recent years, the rated power of wind turbines has gradually increased, as a result of the increase in rotor diameter therein, which in turn makes it essential to use taller towers to support them. This increase in height generally implies that the tower comprises different sections along its total length, which sections are placed one on top of the other to form its complete structure and which, in turn, can be transported from their point of manufacture to their point of installation. For example, to mount a 100 m high tower, five 20 m high stackable sections can be used so that, with these dimensions, the sections are suitable for transport by road and/or rail.
Moreover, to ensure that the increase in height of the towers does not imply a decrease in their stability or stiffness, one option is to increase the transverse dimensions of the tower gradually, from the top to the base. However, such an increase may imply, again, problems in transporting the sections, which makes it necessary in practice to divide each section into longitudinal modules, made up, for example, of voussoirs.
As the rated power of wind turbines increases, the weights and dimensions of all turbine components (rotor, blades, etc.) also increase accordingly, with the following aspects being of particular relevance for mounting costs:
More specifically and by way of example, the weights of the complete tower sections of a 3 MW wind turbine tower can exceed 200 tons, which imposes severe requirements and constraints on the cranes used for mounting it. The use of these cranes generally has a high impact on execution times and costs, for two main reasons. Firstly, due to the low availability of cranes of this type, which translates into a high daily rental cost. And secondly, due to the high operational and logistical costs associated with transporting them, due to the large number of trucks required to move them. Typically, the cost of renting a crane for mounting a tower can amount to €80,000 per week, together with the almost €100,000 it generally costs to transport it (conventionally using at least forty trucks). This limitation represents, at present, the need to find alternative means and methods for the construction of wind turbine towers.
During the operation of a crane for mounting towers, the configuration used depends mainly on two factors: the lifting height and the individual weight of each of the elements to be lifted. In this sense, each of the crane elements has to be arranged in a suitable way for said configuration, which is generally not valid for lifting at other heights and weights. For the most part, cranes comprise one or more height (or, commonly, “jib”) configurations, which determine both the maximum lifting height and the maximum weight that can be lifted.
For mounting towers constructed with voussoir modules, there are several methods that can be followed, which can be grouped mainly into the two groups described below:
Thus, an object of the present invention is to provide a method for installing/mounting towers made of concrete based on a plurality of pre-mounted tower segments (preferably as a succession of voussoirs, or similar modules), which reduces the number of crane configurations required for lifting same, although it can also be favorably used for other types of towers. Preferably, the invention is applicable to towers made of concrete with a frustoconical section, typically used to support the high moments at the base of the tower. However, its object can also be carried out in other types of section configuration, such as cylindrical, polygonal, etc., or other materials such as steel.
In order to overcome the technical problems described in the preceding paragraphs, the present invention proposes a novel method of mounting towers made of concrete, which is essentially based on optimizing crane configurations required during said mounting, by means of an advantageous arrangement of the lengths and weights of the segments that are part of said tower.
A tower constructed by means of stacking two or more essentially tubular or frustoconical segments, although without limitation to geometries of another type is obtained by means of said method, comprising at least:
Advantageously, the present invention proposes a novel configuration of the stacked segments of the tower based on a selection of their individual lengths and weights, which allows the crane operations required for the complete lifting of the components of the tower to be optimized.
Said selection comprises defining one or more “mounting groups”, each one being made up of one or more stacked segments, wherein each mounting group is installed using just one crane configuration.
A certain mounting crane model can adopt different configurations. One certain configuration is characterized, among other aspects, by the length used for the crane jib. The maximum loading capacity of the crane varies, generally on the basis of which the configuration is used. The maximum height at which the crane can mount a given element also varies, logically being higher the longer the length of the jib used is.
To be able to use said configuration, the different lifting points of said segments in the tower will be at a lower level than the loading point of the crane or, in other words, said lifting point will always be kept at a higher level than the level of the segments of one and the same mounting group.
Similarly, each of the stacked segments in one and the same mounting group will have a maximum weight smaller than the maximum lifting load weight allowed by the crane used with the configuration used for installing said mounting group.
To that end, it is possible to modify the length and the thickness of the different stacked segments, such that the restriction described above is respected.
More specifically, a first object of the invention relates to a method for installing a tower formed by the stacking of two or more mounting groups on a base section, wherein at least one of said mounting groups is formed by a plurality of stacked segments;
wherein said method comprises at least the following steps performed in any order that is technically possible:
Advantageously, in said method at least two or more stacked segments are installed consecutively in the corresponding mounting group with one and the same mounting crane jib configuration, wherein the length (I) of the lowest stacked segment of said mounting group is smaller than the length (I) of at least another stacked segment of the aforementioned mounting group.
In a preferred embodiment of the method of the invention, a plurality of or all the mounting groups are formed by two or more stacked segments. Said embodiment is suitable in very high towers, wherein all the mounting groups are made up of several constructive elements.
In a preferred embodiment of the method of the invention, the base section has a length (I) longer than the length (I) of each of the stacked segments.
In another preferred embodiment of the method of the invention, the length (I) of the base section exceeds the length (I) of at least one of the stacked segments of the tower by at least 50.0 cm.
In another preferred embodiment of the method of the invention, the length (I) of the stacked segment arranged immediately above the base section is equal to or smaller than the length of at least another stacked segment in the same mounting group.
In another preferred embodiment of the method of the invention, one or more of the stacked segments or the base section are formed by cylindrical elements made of metal and/or concrete, with a continuous structure and/or shaped as voussoir joints.
In another preferred embodiment of the method of the invention, one or more of the stacked segments are formed by voussoirs and said voussoirs are assembled at the base of the tower.
In another preferred embodiment of the method of the invention, said method is applied to a tower of a height greater than or equal to 100.0 m.
In another preferred embodiment of the method of the invention, a tower comprises two mounting groups, and wherein each mounting group comprises two stacked segments.
In another preferred embodiment of the method of the invention, a nacelle and/or wind turbine blades are installed on the top mounting group.
In another preferred embodiment of the method of the invention, the mounting crane is a mobile type mounting crane.
In another preferred embodiment of the method of the invention, a crane different from the mounting crane for installing the base section of the tower is used.
A second object of the invention relates to a tower manufactured by means of the method of the invention according to any of the embodiments thereof described herein. Preferably, said tower comprises a nacelle and/or one or more wind turbine blades on the top mounting group.
As an exemplary embodiment of the invention based on
The arrangement of each of the segments (4, 5, 4′, 5′) in the tower (1) can be defined by the lifting height h; (i.e., the height at which the top end of each segment (4, 5, 4′, 5′) is installed in the tower (1) assembly); and by the lifting weight wi, which corresponds to the weight supported by a crane for lifting said segment (4, 5, 4′, 5′) up to the corresponding lifting height hi. In the mentioned exemplary embodiment, the stacked segments (4, 5, 4′, 5′) will be respectively defined by four lifting heights h4, h5, h4, h5 and their corresponding lifting weights w4, w5, w4′, w5, which will in turn depend on the dimensions and manufacturing material of the segment (4, 5, 4′, 5′). Similarly, both the base section (3) and the segments (4, 5, 4′, 5′) preferably have a characteristic length li and a diameter di. The sum of the individual lengths 14, 15, 14, 15 of each segment (4, 5, 4′, 5′), together with the length l3 of the base section (3), corresponds to the total length of the tower (1).
In order to ensure that the tower (1) assembly can be installed by means of just two crane configurations, two threshold values H, H′ for the jib height of said crane will be preset, with the corresponding maximum loads W, W′ allowed for said jib heights H, H′, respectively. From said threshold values, it will be imposed on each of the segments (4, 5) of the first mounting group (2) (i.e., the group (2) installed immediately above the base (3) of the tower (1)) that the corresponding lifting heights h4, h5 be smaller than or equal to the lowest of the preset jib threshold values (in the example of
Similarly, it will be imposed that the lifting weights (w4, w5) corresponding to the segments (4, 5) of the first mounting segment (2) are equal to or smaller than the highest (W) of the jib load (or “counterweight”) threshold values preset, such that they can be effectively lifted by the crane by means of the selected jib configuration. Accordingly, for the second stacked group (2′) (i.e., the one arranged on the first group (2)), the lifting weights (w4, w5) corresponding to the respective segments (4′, 5′) will be required to be smaller than or equal to the lowest (W) of the preset jib threshold values.
To illustrate the different steps of the proposed method, the case of being applied to installing a tower (1) according to the mounting groups (2, 2′), base section (3) and stacked segments (4, 5, 4′, 5′) described in the preceding paragraphs is described below. For lifting said segments (4, 5, 4′, 5′) on the base section (3), a crane characterized by the jib (P) configurations described in Table 1 below is used:
In the aforementioned Table 1, each crane configuration is defined by its jib P length, the maximum lifting height H that can be reached with said jib length, and its corresponding maximum lifting weight W.
For the example of a tower (1) with a length of 120 m, based on an arrangement of a base section (3), two mounting groups (2, 2′) and two stacked segments (4, 5, 4′, 5′) for each group (2, 2′) (see
In light of the described example, it can be seen how, by means of the method of the invention, it is possible to install the tower (1) assembly of large dimensions by means of two single crane jib P configurations, substantially improving overall assembly mounting and installation times. This is further associated with a significant reduction both in the risks of error or failure arising from the reconfiguration of the crane jib (since the present method reduces the number of reconfigurations required), and the costs associated with said installation. Alternatively, the method of the invention can allow the number of stacked segments (4, 4′, 5, 5′) required in a tower (1) of a given height to be mounted with a given mounting crane model to be reduced, which translates into a higher mounting efficiency and speed by reducing the number of elements of the tower (1), with the corresponding cost reduction.
Therefore, by following the method of the invention, each of the segments (4, 5) of the first mounting segment (2) (i.e., the group (2) installed immediately above the base (3) of the tower (1)) has lifting heights h4=53.0 m, h5=76.0 m equal to or smaller than the lowest of the preset jib threshold values (H=80.0 m in the example). In the same way, for the second stacked group (2′) (i.e., the one arranged on the first group (2)), it is satisfied that the lifting heights h4=96.0 m, h5=120.0 m, corresponding to the respective segments (4′, 5′) are equal to or smaller than the highest of the preset jib threshold values (H′=124.0 m in the example).
Similarly, it is satisfied that the lifting weights w4, =250.0 t, w5=200.0 t corresponding to the segments (4, 5) of the first mounting group (2) are equal to or smaller than the highest of the jib load threshold values preset (W=263.0 t in the example). Accordingly, for the second stacked group (2′) (i.e., the one arranged on the first group (2)), it is satisfied that the lifting weights w4=125.0 t, w5=120.0 t, corresponding to the respective segments (4′, 5′) are equal to or smaller than the lowest of the preset jib threshold values (W′=125.0 t in the example).
In contrast with the proposed method, an exemplary method different from the method proposed by the invention according to the known embodiments from the prior art will be described. In said example (see
As shown in Table 3 and
As for the specific dimensions of the base section (3) and segments (4, 5, 4′, 4″) of the tower (1), it is possible to change such dimensions based on the particular requirements of each installation, required, for example, by the orographic, climate, or structural conditions of its location. In any case, to ensure the installation capacity by means of just two crane configurations, the above-mentioned relationships referred to lifting heights hi and lifting weights wi must be verified in any of the embodiments used and, by using a distribution of lengths such as the one which characterizes the invention, this can be achieved by minimizing the number of crane configurations required.
In a specific embodiment of the invention, the base section (3) can have a length longer than the rest of the stacked segments (4, 5, 4′, 4″). This achieves obtaining a more robust support structure of the tower (1) and reduces the weights of the stacked of the tower (1). More preferably, the length of the base section (3) exceeds by at least 50.0 cm the length of at least one of the stacked segments (4, 5, 4′, 4″) of said tower (1) segments (4, 5, 4′, 4″).
In another embodiment of the invention, the length of the stacked segment (4) arranged immediately above the base section (3) is equal to or smaller than the length of at least another stacked segment (5) in the same mounting group (2).
As for the manufacturing materials of the tower (1), the method of the invention can comprise the use of stacked segments (4, 5, 4′, 4″) formed by tubes made of metal and/or concrete both in a continuous manner and formed with voussoir joints. The combination of segments (4, 5, 4′, 4″) made of metal and of concrete is also possible. In the event that the stacked segments (4, 5, 4′, 4″) are formed by voussoirs, these will preferably be assembled at the base of the tower (1) to be installed in the assembly.
In turn, the base section (3) can also be constructed as a continuous element or as a plurality of voussoirs, and the material for manufacturing it will preferably comprise concrete.
Similarly, the method for installing the present invention is preferably applied to towers (1) of heights equal to or greater than 100.0 m, for which the reduction of crane configurations represents a particularly valuable advantage. More preferably, said towers comprise two mounting groups (2, 2′), wherein each group (2, 2′) will comprise two stacked segments (4, 5, 4′, 4″).
In a preferred embodiment of the invention, the top mounting group (2′) comprises the nacelle and/or wind turbine blades.
In another preferred embodiment of the method of the invention, the crane used for installing the tower is a mobile type crane, for example with wheels or chains.
| Number | Date | Country | Kind |
|---|---|---|---|
| P202130921 | Oct 2021 | ES | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/ES2022/070617 | 9/29/2022 | WO |
