Lifting system for erecting, maintaining or dismantling a floating wind turbine

Abstract

The invention relates to a lifting system (1) for erecting, maintaining or dismantling a floating wind turbine (4), which comprises: - a tower (11) comprising at least two elements (11A-11D) which can be telescoped together such that it can assume at least a retracted position, and a deployed position; - and a crane (12) mounted on an upper element (11A), this crane being mobile in rotation about a vertical axis (X1) of the system. Such a system, mounted on a dock, can be used in the deployed position to work on a wind turbine, and, in the retracted position, as a harbour crane.

Description

[0001] Description

[0002] Title: Lifting system for the assembly, maintenance or disassembly of a floating wind turbine.

[0003] The present invention relates to the field of assembly, maintenance and disassembly of floating wind turbines.

[0004] The assembly, maintenance or disassembly of a wind turbine requires significant lifting equipment, both in terms of lifting capacity and working height. The problem is greater for offshore wind turbines. Thus, for maintenance of a wind turbine, for example to replace a blade, a gearbox or an alternator, these lifting equipment can be brought out to sea, to the location where the wind turbine is installed; such lifting equipment is difficult to mobilize and the intervention is particularly expensive. A second solution, when the wind turbine is floating, is to bring it back to a port to use a land-based crane.

[0005] If the wind turbine is brought back to a port, the cranes that are generally available do not allow for working at great heights on the moving parts of a wind turbine or its nacelle. In this case, a land-based mobile crane must be used. However, such a crane has many disadvantages:

[0006] - such a crane is rare and its mobilization time can be several months;

[0007] - it is particularly bulky; it requires a large footprint, particularly during assembly and disassembly;

[0008] - its assembly and disassembly time is more than one week for each operation;

[0009] - a high cost; and,

[0010] - a usefulness limited to intervention on the wind turbine. For example, in 2021, to install a blade of the “Haliade-X” wind turbine prototype at a height of nearly one hundred and fifty meters above the ground, this blade weighing two hundred tons with its lifting tool, it was necessary to use a “Liebherr 11350” crane which costs several hundred thousand euros to mobilize.

[0011] The aim of the invention is to propose lifting means allowing the assembly, maintenance or disassembly of a floating wind turbine at the quayside and which anticipates the continuous increase in the size of wind turbines.

[0012] According to the invention, such a system for the assembly, maintenance or disassembly of a floating wind turbine comprises:

[0013] - a tower comprising at least two elements which can be telescoped together so that the tower can take at least one retracted position, in which the tower has a minimum height, and one deployed position, in which the tower has a maximum height;

[0014] - and a crane mounted on an upper element among the telescoping elements, movable in rotation around a vertical axis of the system.

[0015] Advantageously, the system comprises a mobile gantry, preferably mobile on rails, the tower being carried by this mobile gantry.

[0016] Preferably, the crane is a luffing jib crane.

[0017] The invention also relates to a lifting method in which a system according to the invention is installed along a quay and in that this system is used for loading or unloading a ship.

[0018] Several embodiments of the invention will be described below, by way of non-limiting examples, with reference to the appended drawings in which: [Fig. 1] is a schematic elevation view of a lifting system according to the invention during manipulation of a blade of a floating wind turbine;

[0019] [Fig. 2] is a top view of the lifting system in the configuration of Figure 1;

[0020] [Fig. 3] is a view similar to that of Fig. 1, in which the system is being manipulated from an alternator of the wind turbine; and,

[0021] [Fig. 4] is an elevation view of the lifting system, in harbor crane configuration, loading a barge.

[0022] The figures illustrate a lifting system 1 according to the invention. In the example illustrated, the system is arranged on a quay 2 of a port. Preferably near the edge 3 of the quay. Thus arranged, the system 1 allows the construction, maintenance or deconstruction of a floating wind turbine 4 berthed at the quay 2, which is illustrated by figures 1 to 3. When such a system 1 is not occupied by a wind turbine, it can also be used for the current activity of the port, for example the loading of a barge, which is illustrated in figure 4.

[0023] The lifting system 1 comprises a telescopic tower 11 and a crane 12 mounted on top of the tower 11. In the example illustrated, the tower is mounted on a gantry 13. The gantry is arranged on rails 13R, visible in Figure 2;

[0024] 11 allows system 1 to be moved parallel to edge 3 of quay 2. The crane

[0025] 12 includes a lifting boom 14, articulated around a tilting axis XI 4. The crane illustrated is of the PC400 type, supplied by Favel-Favco-Berhad (Malaysia).

[0026] In the example illustrated, the tower 11 comprises four elements 11A-11D designed to slide vertically relative to each other. Each element has a substantially square horizontal section; it is mainly made of a lattice of metal beams. A first element 11A is rigidly fixed to the gantry; a second element 11B, of reduced section, is slidably mounted inside the first; a third element 11C, of ​​smaller section, is slidably mounted inside the second; the fourth element 11D, of even smaller section, is slidably mounted inside the third element. The fourth element 11D is the upper element and supports, at its top, the crane 12. The crane is mounted so that it can rotate around the axis XI of the system 1 relative to the upper element 11D.

[0027] The wind turbine 4 illustrated in Figures 1 to 3 comprises a rotor 21, of axis XL. The rotor carries three blades 22. It is fixed to a nacelle 23 arranged at the top of a mast 24, of vertical axis X4. The mast is fixed to a floating platform 26. The platform 26 comprises three floats 27 connected to each other by a beam structure 28.

[0028] In the example of figures 1 and 2, the floats 27 are regularly distributed around the axis X2 of the mast.

[0029] Figures 1 and 2 illustrate a method for handling one of the blades 22 using the lifting system 1.

[0030] In order to reach blade 22A, tower 11 is in the deployed position. The wind turbine is docked at the quay and the manipulated blade 22A is arranged substantially horizontally. As particularly illustrated in Figure 2, the nacelle 23 is oriented around the axis X4 of the wind turbine so as to limit the horizontal distance DG between the center of gravity G and the axis XI of the system 1. A spreader 31, carried by the crane 12, allows the blade 22A to be taken by the crane 12. The crane comprises a counterweight 32, chosen so that the load exerted by the crane 12 and the blade 22A is exerted substantially along the axis of the system 1. Figure 3 illustrates a method for handling heavy equipment 41 of the nacelle 23 of the wind turbine 4, using the lifting system 1. This equipment may be an alternator or a gearbox of the wind turbine or any other element of the nacelle that it would be necessary to install or handle.In order to be able to place the equipment 41 in the nacelle 23, the tower 11 is in the deployed position.

[0031] In the example of Figure 3, the wind turbine differs from that of Figures 1 and 2, in that the mast 24 is not centered, but rises above a float 27. This arrangement makes it possible to approach the nacelle to the axis of the system 1. Of course, the system is suitable for performing the same operation with a wind turbine of the type of Figures 1 and 2, or any other type of floating wind turbine capable of being brought alongside.

[0032] Figure 4 illustrates the use of system 1 as a port crane for unloading a package 50 onto a ship, here a barge 5.

[0033] A horizontal movement of the loaded system is made possible by the movement of the gantry 13 on the rails 13 R.

[0034] In the example illustrated, and to have an order of size of system 1, the top of platform 2 having a level N2 considered as "zero", as an example we give the following figures:

[0035] - NA support level of the first element: 17.5 meters;

[0036] - level N21 of axis X21 of rotor 21 of wind turbine 4: 158 meters.

[0037] In the position of Figures 1 to 3, with the tower fully extended, the level N14 of the tilting axis X14 is approximately 140 meters; and, in the position of Figure 4, with the tower fully retracted, the level N14 of the tilting axis X14 is approximately 40 meters. Of course, these dimensions can vary; in particular, they can increase to allow work on wind turbines whose size tends to increase with the power of the wind turbines and the development of new offshore wind farms.

[0038] Of course, the invention is not limited to the examples just described. On the contrary, the invention is defined by the claims which follow.

[0039] It will indeed appear to those skilled in the art that various modifications can be made to the embodiments described above, in light of the teaching which has just been disclosed to them.

[0040] Thus, the number of elements of the tower may be other than four; each or all may have a section which is not square, for example circular or polygonal; each or all may also be formed otherwise than by a lattice of girders, for example by solid sheets.

[0041] The number of tower elements and their respective height are calculated so that in the retracted position the system has optimal dimensions for use as a harbor crane and in the deployed position the system has optimal dimensions for use in the maintenance of a floating wind turbine.

[0042] The crane counterweight is optional. If the crane includes a counterweight, it can be radially movable, so that by moving it away from or closer to the system axis, a load descent is maintained substantially along this axis.

[0043] The relative position of the system and the wind turbine, for example a blade, can vary, the only requirement being that what is to be manipulated, for example a blade, allows its manipulation by the system.

[0044] Unlike existing cranes, a system according to the invention makes it possible to achieve very high lifting heights by means of a rotating crane mounted on a telescopic tower with high vertical slenderness. Since the load passes substantially through the neutral fiber of the mast, or at least in the envelope of the support base, the problems of bending moments are reduced and controlled.

[0045] A system according to the invention may not include a gantry. It is then used fixed relative to the platform on which it is installed.

[0046] Since the system is capable of taking loads, installing or uninstalling them within a limited perimeter around the mast axis, there is no need to manage counterweight modifications which are time-consuming and therefore costly.

[0047] Being able to leave the system stationary in the retracted position eliminates the risks caused by strong winds, which are significant at the seaside.

[0048] The dual-use capability of the system, both for loading and unloading ships and for installing and removing wind turbine parts from the quayside, is a real added value for a port with a construction vocation.

[0049] Furthermore, since a system according to the invention remains stationary on its platform, its footprint is reduced. It requires neither assembly time nor space, apart from the very short time required to deploy or fold the tower.

[0050] The system replaces a pre-existing quayside crane for loading or unloading ships without penalty, based on the principle that less is more. The system is and remains versatile for use between conventional heights for vessels of all sizes and, for example, up to 150 meters for current high-capacity floating wind turbines.

Claims

CLAIMS 1. Lifting system (1) for the assembly, maintenance or disassembly of a floating wind turbine (4), characterized in that it comprises: - a tower (11) comprising at least two elements (11A-11D) telescopable with each other so that said tower can take at least one retracted position, in which the tower has a minimum height and a deployed position, in which the tower has a maximum height; - and a crane (12) mounted on an upper element (11D) among said telescopable elements (11A-11D), movable in rotation around a vertical axis (XI) of said system (1).

2. System according to claim 1, characterized in that it comprises a mobile gantry (13), preferably mobile on rails (13R), said tower (11) being carried by said mobile gantry.

3. System according to one of claims 1 and 2, characterized in that the crane is a crane with a luffing jib (14).

4. Lifting method in which a system (1) according to one of claims 1 to 3 is installed along a quay and in that the system (1) is used for loading or unloading a ship (5).

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