Patent Application
20210222452
The present invention relates to a movable module for hoisting telescopic towers, for example concrete and/or metal telescopic towers. The primary sector of application thereof is the construction industry, particularly in assembling towers, and more specifically telescopic towers.
High-rise tower structures such as those commonly used for supporting wind turbines are often constructed by means of prefabricated reinforced and/or prestressed concrete segments which are subsequently transported to the installation site where they are hoisted by means of a crane and assembled in their final position. In the case of towers having a circular cross-section, each vertical section is generally assembled from connected segments. The lower section of the assembly tower is erected first, and after that successive sections are hoisted onto the lower section, being lifted to their final position using a crane. The sections are usually pre-assembled at ground-level, although, alternatively, the segments of a particular section can be hoisted separately and then be assembled in the upper part of the previous section. As a final step in the installation method, the upper section is hoisted such that it supports the assembly formed by the generator and the rotor of the wind turbine.
Wind turbine towers can reach heights in the order of 100-150 m, supporting generation units capable of producing power in the order of one to tens of megawatts. Conventional techniques for constructing these towers require the segments of the tower to be lifted using large cranes, which must present hoisting heights of at least the total height the structure of the tower itself. The generator unit, which may weigh up to 200 tons, also has to be lifted to its final position at the upper part of the structure. For this purpose, cranes that are able to safely lift these weights to such heights are very large and expensive, and the process of transporting a crane of this type to the installation sites, as well as the installation thereof, is a complex task that requires skilled workers, heavy-duty machinery and, often, the construction of roads to allow the different elements forming the tower to be transported. These complications are also reproduced during tower maintenance and repair tasks after the tower is installed.
Patent application WO 2009/010771 A2 describes a method of hoisting a telescopic tower in which several prefabricated telescopic sections of a tower are horizontally assembled at the ground-level. Said telescopic sections are hoisted together in the vertical position, either by means of a crane or by lifting each section against its outer neighboring section, using an arrangement of supporting elements and extendable connectors such as powered jacks. In the raising method described in said application, each vertical section is nested in the contiguous outer section thereof, such that the wall elements form an additional supporting wall covering the inner surface of each outer tower section.
The method of hoisting a tower described in WO 2009/010771 A2 suffers, however, from the following drawbacks. First, the method is based on the support of a flange in the lower part of each tower section, on a projection in the lower part of the inner section. This implies that the sections must be hoisted in a specific order, since each successive inner section rests on its outer neighboring section. Secondly, the method of WO 2009/010771 A2 is excessively toilsome, since it implies the construction and subsequent dismantling of an entire inner wall structure (which is almost as large as the tower itself), which may have a serious impact on the tower construction speed. Third, the described method is only suitable for structures in which all the walls of all the sections of the tower are substantially parallel.
As an alternative to the method proposed in application WO 2009/010771 A2, improved methods of hoisting have been considered, such as the method described in international patent application WO 2011/006526 A1. This method is based in a plurality of telescopic sections, arranged at the ground-level in a substantially coaxial manner, with an innermost section and one or more sections arranged around said innermost section, forming telescopic sections forming the total length of the tower. For fixing the sections to one another, a fitting step is performed through a plurality of jacking tendons between upper and lower points of said telescopic sections, where tension is applied to said tendons by means of hydraulic jacks, such that the weight of each section is supported at the upper jacking points of the contiguous section, and the sections are raised as tensioning is performed on the mentioned jacking tendons.
Although the alternative described in WO 2011/006526 A1 allows the processes of installing conventional telescopic towers to be improved, it still presents problems left unsolved in the state of the art fundamentally relating to the complexity of the pre-installation steps and the execution times for hoisting tower sections. More specifically, the invention described in said application comprises a first installation phase for installing the tendons in each of the telescopic sections, and later phases in which the hydraulic jacks are connected to and released from the cables in order to perform the various hoisting operations for completely raising the tower. However, this implies the necessary delay in pre-installation and hoisting times, since a prior task of placing the loose cables and a subsequent task of connecting the hydraulic jacks to said cables are necessary. Furthermore, for each of the different hoisting operations that may be involved for a tower, the hydraulic jacks must be released from the cables and connected to others, with the corresponding increase in work, time, and risk, as said jacking points are sensitive and bear enormous responsibility.
For the purpose of solving this and other problems inherent to the prior art, the objective of the present invention is to provide a movable module and a method of hoisting which allows the sections of the tower to be assembled without a crane, or with the use of a small crane having a size substantially equal to the size of a tower section, where said method comprises hoisting the tower sections much more quickly and more efficiently than with the known techniques, which further allows the use of tower sections having non-parallel walls.
The present invention provides a movable module for hoisting telescopic towers and the corresponding method of hoisting telescopic towers, said towers preferably being concrete and/or metal towers, which allows the process for hoisting them to be optimized.
Another objective of the present invention is to also provide a system which allows the number of operations to be performed during said method to be reduced, thereby avoiding more complicated processes, and reducing costs, times, and risks.
With the proposed invention, the operation time is furthermore reduced, and the entire process is streamlined, which at the same time allows the time for hoisting the towers to be reduced, which represents important operative and economic savings. Furthermore, considering that wind farms usually comprise a large number of towers, the present invention qualitatively improves the capacity and ease for reclaiming and reusing hoisting means and equipment in the different towers of a farm.
The objects described above are achieved by means of a movable module for hoisting telescopic towers, preferably wind turbine towers, an ascending section of the tower being hoisted in relation to a supporting section of the tower immediately outside, where said movable module advantageously comprises:
Likewise, during hoisting of the tower, the movable module is temporarily fixed to the head of the supporting section, and the grouping means are temporarily fixed to the base of the ascending section.
More specifically, the objective of the invention is performed by means of a movable module for hoisting telescopic towers and a method of hoisting telescopic towers according to the claims herein.
The fact that the hydraulic jack and hoisting cable are conveniently and permanently integrated in a single mobile piece of equipment throughout the performance of the method of hoisting the telescopic tower, together with the grouping means arranged at a free end of at least one hoisting cable, are a key aspect of the present invention since, unlike the previous inventions, they allow avoiding the successive and numerous operations of previously placing loose cables and connecting and releasing the hydraulic jacks and cables, facilitating and streamlining the entire process, and improving its reliability. The module herein described thereby allows, during its application, the steps of positioning the hoisting cables and the raising of each section to be performed in a single step, optimally reusing the cables for different hoisting operations and without implementing any of connection/disconnection operation between the hoisting cables and the hoisting jacks.
Likewise, the movable module can be easily moved so as to be placed in the different positions established for hoisting the different sections of the tower. Furthermore, said module moves at all times as a single part, that is, only one movement between hoisting phases is necessary, greatly improving streamlining and cost. This feature differs entirely from the solutions known in the current state of the art, where the elements must be mobilized one by one, which implies a significant advantage of the present invention over the current state of the art.
Additionally, the objectives described above are achieved by means of a method of hoisting telescopic towers using a movable module according to the present invention, characterized in that it comprises the following steps performed in any technically possible order:
Said movable module may comprise also at least one cable guiding structure which allows guiding the hoisting cable protruding from the upper part of the hydraulic jack.
Likewise, the module may also comprise at least one cable take-up element which can furthermore be arranged in a raised position, such that the circulation of workers is facilitated. In this sense, this position of the take-up element largely facilitates the operations to be performed, which allows the free circulation of operators and represents another considerable advantage of the invention by reducing the dimensions of the work platform and/or avoiding the installation thereof. Said take-up element can be in the form of a drum or recoiler, or any similar or equivalent element known in the art. The take-up element can be passive or active, incorporating a motor or the like to collaborate in the deployment and/or drawing-in of the hoisting cable.
Additionally, the movable module may also comprise a guiding element in contact with the ascending section, which is preferably a sliding or rolling contact, and/or contact by means of caterpillar track-type elements.
In turn, the method of hoisting telescopic towers described above may comprise the hoisting of at least two different sections of the tower, the main steps of the method being repeated for hoisting different sections of the tower. In this case, said method may be characterized in that the innermost section of the tower is initially hoisted, and hoisting is continued from the innermost to the outermost section.
In said method of hoisting telescopic towers, the heads of different tower sections to be hoisted can be positioned at considerably the same level. The movable module of the invention can thereby be moved radially for the positioning thereof at the heads of the different tower sections, through at least one horizontal movement means, for example one or more rails.
Likewise, said method may be characterized in that the described grouping means may be reclaimable and comprise:
Said wedge plate may comprise a protective element allowing it to run through the conduits of the different sections intended for housing the hoisting cables. Likewise, said protective element of the wedge plate may be pointed to prevent jamming.
The preceding and other features and advantages will be better understood from the following detailed description of embodiments in reference to the attached drawings, which must be considered by way of illustration and not limitation, in which:
Preferably, the hoisting cable (3) is formed by a plurality of strands (3′)(see the schematic distribution thereof in
More preferably, the strands (3′) are integrated in the hoisting cable (3) independently, that is, the strands (3′) are not intertwined or mechanically connected, but rather are grouped together in a substantially parallel bundle.
The movable module (1) of the invention also has grouping means (4) intended for preventing the strands (3′) from crossing each other, as well as to facilitate threading the hoisting cable (3) through the head of a supporting section (211) and the base of an ascending section (210) (see said sections in
Additionally, the grouping means (4) are essentially positioned at the lower end of the hoisting cable (3), keeping all the strands (3′) making up said hoisting cable (3) grouped together. In addition to grouping, the grouping means (4) contribute to keeping the strands (3′) positioned so as to maintain the distribution thereof which is used both in the hydraulic jack (2) and at the lower end of the cable, furthermore being able to act as anchoring means for holding said position.
In additional embodiments of the invention, the grouping means (4) can be detachable, being removable for adding anchoring means, and being added again at the lower end of the cable at a later time of the method of hoisting the tower (100).
As described, the movable hoisting module (1) of the invention allows a two-way movement of the hoisting cable (3) through the hydraulic jack (2), said hoisting cable (3) being able to both be extended in the essentially descending direction and be taken up in essentially the ascending direction.
In a preferred embodiment of the invention, the mean diameter “D” of the hoisting cable (3) is less than 4·d·(N)1/2, where “d” is the mean diameter of the strands (3′) forming the hoisting cable (3) and “N” is the total number of strands (3′). This thereby achieves the hoisting cable (3) presenting suitable dimensions for going through the flanges of the sections (210, 211) of the telescopic tower (100).
The movable module (1) of the invention preferably comprises a supporting frame (2′) to which the lower part of the hydraulic jack (2) is fixed, and comprising a channel for the passage of the hoisting cable (3), the dimension of which allows housing the grouping means (4). Thus, the movable hoisting module (1) can adopt a transfer position in which the hoisting cable (3) is completely drawn in or taken up, and in which the lower end of the hoisting cable (3) and the grouping means (4) are housed in a channel of the frame (2′). As a result of this configuration, the movable module (1) may be transferred between hoisting operations or between towers, or even between farms, supported on its frame (2′). To that end, in the transfer position the cable (3) is prevented from protruding below the frame (2′). Likewise, in different embodiments of the invention, the movable module (1) may comprise one or more jacking points (not shown in the figures) which allow suspending the module completely. Said jacking points are preferably positioned substantially on the vertical of the center of gravity of the movable module in its transfer position.
In another preferred embodiment of the invention, the frame (2′) may adopt a horizontal dimension such that the movable module (1) simply supported on said frame (2′) is sufficiently stable against horizontal loads, which facilitates storage and transfer of the module (1), for example, between towers of the farm.
In another preferred embodiment of the invention, the frame (2′) comprises horizontal movement means (8) for facilitating the horizontal transfer of the movable module (1) for different hoisted. Said movement means (8) can be of any of the types known in the art for the movement of equipment, such as rails and/or rolling means, or elements for facilitating the sliding of the module (1). They may likewise incorporate or use pushing or pulling means for applying force to move the module (1) from one position to another (for example, from the head of one supporting section (211) to the next one).
In a preferred embodiment of the invention, the movable module (1) further comprises one or more work platforms and/or equipment storage, preferably connected to the frame (2′). The equipment that can be housed in the mentioned platforms is typically power pack-type systems (hydraulic pumps) or manifolds which allow hydraulically powering the jacks (2) and/or controlling their operation. They may also incorporate telecommunication means for facilitating the remote control of the movable module (1).
The arrangement of a work platform (300) which is smaller as a result of the cable take-up elements (6) being arranged in a raised position, thereby facilitating the circulation of workers, can be observed in this embodiment.
The additional arrangement of three hoisting modules (1) arranged in the outermost section of the tower (100) acting only in the last phase of hoisting due to the need to lift the entire structure, with a much greater weight than in the preceding phases, can also be observed.
Once hoisted, as shown in
Lastly,
As described above, an advantage of the method of the invention is that it does not require any step of connecting and/or disconnecting between the hoisting cable (3) and the hydraulic jack (2), or any operation for placing loose cables. The movable module (1) itself is thereby capable of deploying the taken up cable (3) for placing it the hoisting position.
This configuration allows performing the method of hoisting same avoiding the placement of the wedge plate (9) in each hoisting phase, keeping the hoisting cable (3) threaded and connected to the hydraulic jack (2) throughout the entire method.
Lastly,
| Number | Date | Country | Kind |
|---|---|---|---|
| P201830404 | Apr 2018 | ES | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/ES2019/070272 | 4/22/2019 | WO | 00 |
