FR3127932A1 - Method and device for mounting or dismounting a blade on a fixed wind turbine. - Google Patents

Abstract

Method and device for mounting a blade on a wind turbine at sea. The invention relates to a method for handling at least one blade 6A of a wind turbine 1 at sea, in which a system 11 is temporarily mounted on a jack-up platform 12 installed near the wind turbine 1. The invention also relates to a system 11 and a platform 12 adapted to the implementation of this method. Figure for abstract: Figure 2

Description

Method and device for mounting or dismounting a blade on a fixed wind turbine.

The present invention relates to the field of wind turbines installed at sea. It relates particularly to the assembly or disassembly of the blades of such wind turbines.

When the seabed is shallow enough, the wind turbine can include a mast directly anchored to the seabed. These fixed wind turbines are generally part of a wind farm and significant resources are mobilized to erect them, in particular to install the foundation, then to install the mast and fix the turbine and its blades to it.

However, when it is necessary to change a blade of such a wind turbine, we only know how to use Jack-ups, that is to say self-elevating floating platforms equipped with feet and equipped with a luffing jib crane. These platforms rest and lift themselves on the seabed thanks to their columnar legs. It is very delicate to handle a blade and it requires significant resources, both in terms of height capacity and load capacity. Jack-ups with sufficient capacities are few in number, not very available and their intervention is extremely expensive.

The problem to be solved consists in finding a method and means for changing a blade of a wind turbine, more quickly, more simply and less expensively than with the known methods and means.

To solve this problem, the invention proposes a method for handling a load on a wind turbine which comprises a mast rigidly fixed to a seabed and a nacelle carried by this mast of the wind turbine, this nacelle comprising a rotor having blades which extend radially, comprising steps for:

- provide a jack-up platform;

- immobilize the platform near said wind turbine; Then,

- Mount a lifting system on the platform, system comprising a substantially vertical mast along an axis of the system and consisting of several elements and a lifting tool fixed on an upper element;

- immobilize the nacelle in a position allowing the handling of said load;

- raise the mast;

- enter the load;

- lower the mast; Then,

- release the movements of the nacelle and the rotor.

Thus, a method for handling or fixing or removing a blade of a wind turbine which comprises a mast rigidly fixed to a seabed and a nacelle carried by this mast, this nacelle comprising a rotor having blades which extend radially, comprises steps for:

- provide a jack-up platform;

- immobilizing said platform near said wind turbine;

- mounting a lifting system on the platform, the system comprising a substantially vertical mast along an axis of the system and consisting of several elements and a lifting tool fixed to an upper one;

- immobilize the nacelle in a position allowing the handling of said load;

- raise the mast;

- handle the blade;

- lower the mast; And,

- release the movements of the platform.

Advantageously, some of the elements are telescopable with each other and the step of raising the system includes a step of telescoping these elements with each other.

According to a second object of the invention, a jack-up platform for implementing a method according to the invention comprises means for attaching a base of the lifting system thereto.

According to a third object of the invention, in a system according to the invention, the tool is fixed substantially to the top of an upper mast element and forms with the mast a "T" shape.

The lifting tool may comprise a horizontal beam mounted at the top of the upper element and forming a "T" with this element, a slider mounted to slide horizontally on the beam, this slider carrying seat means provided for resting thereon a blade. The beam can also be rotatably mounted around the axis of the system and the tool can comprise, at one end of the beam, winch means for lifting a load. Preferably, the seat means are adjustable in height, in particular to conform to the blade which must be deposited there.

The lifting tool may comprise a sleeve and a double jib mounted to slide horizontally in this sleeve and whose two ends each protrude from a respective side of the sleeve, each of the ends carrying a respective lifting cable.

Advantageously, at least some of the elements forming the mast of the system can be telescoped together.

Preferably, the mast comprises a lower element forming a base intended to be fixed on a platform according to the second object of the invention.

According to another embodiment, a system according to the invention may comprise a fixed base relative to the platform, the mast being rotatably mounted on the base around the axis of the system, the lifting tool comprising a substantially horizontal beam rigidly arranged at the top of the upper element, a winch being fixed to the lower element so that it rotates around the axis, at the same time as the mast, and, a cable connected to the winch, the system comprising in addition to a first cable return and a second cable return, each arranged at a respective end of the beam so that:

- between the two transmissions, the cable is substantially horizontal;

- the cable extends vertically between the winch and the first transmission; And,

- a free end of the cable extends beyond the second transmission to suspend a load there.

Advantageously, the system comprises arm means for connecting the mast of the system with the mast of the wind turbine, preferably at least one arm mounted sliding on the mast of the wind turbine.

Several embodiments of the invention will be described below, by way of non-limiting examples, with reference to the appended drawings in which:

schematically illustrates, in elevation, a first step of a first method according to the invention for changing a damaged blade of a wind turbine using a first embodiment of a lifting system according to the invention, step in which a spare blade is brought to a jack-up platform;

schematically illustrates a second step of this process in which the platform is installed at the foot of the wind turbine;

schematically illustrates a third step of this process in which the lifting system seizes the damaged blade;

schematically illustrates a fourth step of this process in which the lifting system uncouples the damaged blade;

schematically illustrates a fifth step of this process in which the lifting system lowers the damaged blade until it can be picked up by a lattice boom crane;

schematically illustrates a sixth step of this process in which the damaged blade is taken up by the lattice jib crane;

schematically illustrates a first step of a second method according to the invention for removing equipment from a nacelle of the wind turbine using the lifting system illustrated in the preceding figures, step in which the system grips the load;

schematically illustrates a second step of the second method in which the system lifts the load;

schematically illustrates a third step of the second method in which the system directs the load;

schematically illustrates, in elevation, a second embodiment for a system according to the invention entering a blade of the wind turbine; And,

schematically illustrates the system of the lowering the blade;

schematically illustrates a step of an improvement of the first embodiment of the system according to the invention as illustrated in FIGS. 7 to 9, in a step of removing a load; And,

schematically illustrates a third embodiment for a system according to the invention, in a step of removing a load.

Certain terms used, such as "left" or "right" are not absolute and generally refer to a position in one of the figures without them being able to be considered as a limitation to the scope of the invention.

Figures 1 to 13 illustrate a wind turbine 1. In the example illustrated, the wind turbine 1 comprises a tubular mast 2 carrying at its top a nacelle 3 of which a single rotor 4 comprises three blades 6 fixed to a nose 7. The wind turbine is a fixed wind turbine installed at sea 8. The mast 2 extends along a vertical wind turbine axis X1 from the bottom 9 of the sea, in which it is anchored.

Figures 1 to 6 illustrate the changing of a blade 6A by a first method according to the invention using a lifting system 11. Figures 1 to 6 illustrate a first embodiment of the lifting system. The system 11 is mounted there on a jack-up type jack-up platform 12. The platform 12 comprises a secondary tilting jib crane 13, made of a wire mesh.

As shown in , the platform 12 is driven by flotation to the wind turbine 1. It carries, lying on its deck 12P, a replacement blade 6B for the damaged blade 6A.

In Figures 2 to 6, the platform 12 is shown immobilized near the mast 2 of the wind turbine 1, standing on its feet 12A which rest on the seabed 9. The platform 12 and the lifting system 11 are arranged so that the axes X1 of the wind turbine and X11 of the system are at a first distance D1 from each other, suitable for the implementation of the first method.

As illustrated in Figures 1 and 2, when moving the platform and when raising it near the wind turbine, the lifting system is in a retracted position P1. To reach the damaged blade 6A, the system can take a deployed position P2, particularly illustrated in Figures 3 and 4.

In the example illustrated, the system comprises a mast 16 and a lifting tool 17. The mast 16 extends vertically along a main axis X11 of the system parallel to the wind turbine axis X1, from the platform 12. The mast 16 comprises a lower element 16A, intermediate elements 16B and an upper element 16C. The tool 17 is fixed to the upper element 16C. The lower element 16A comprises or constitutes a base of the mast 16. The platform 12 comprises fastening means (not shown) for the base of the mast 16. In this first embodiment, the intermediate elements 16B are telescopably mounted between them and inside the lower element 16A; their telescoping makes it possible to raise the mast from the retracted position P1 to the deployed position P2 and conversely to lower the mast from the deployed position to the retracted position.

As particularly illustrated on detail D4 of the , the tool 17 comprises left and right, in the position of the figures. The seats 19A are designed to rest a blade substantially horizontally thereon, so that its center of gravity is located between the two seats. The slider 19 also includes gripper means 19B, arranged above the seat 19A located on the right. The clamp means 19B make it possible to secure the blade on the seat means by clamping the blade between the clamp means and the seat situated below.

A method will now be described for replacing the damaged blade 6A with the spare blade 6B with reference to FIGS. 1 to 6.

In a first step, illustrated in , the platform 12 is driven to the wind turbine 1, with the replacement blade 6B lying on its deck.

In a second step, illustrated in , when the lifting system is sufficiently close to the wind turbine, the platform 12 is immobilized and erected on the seabed. The damaged blade is for its part immobilized horizontally, above the platform 12, and the nacelle 3 is immobilized in rotation around the wind turbine axis X1. In this position of the platform and of the damaged blade 6A, the axis X11 of the system is arranged close to the center of gravity 6G of the damaged blade, and the tool 17 is substantially plumb with the damaged blade.

In a third step, illustrated in , the mast of the lifting system 11 is deployed until it reaches the deployed position P2. The slider 19 is offset along C1 to the left relative to the axis X11 of the system. In this position, the tool 17 comes into contact with the damaged blade and holds it, so that it can be detached from the rotor 4. The center of gravity 6G of the blade 6A is substantially centered on the slider 19. orientation of the T as well as the height of the supports 19A are adjusted so as to guarantee that the following separation step is done without damaging either the blade 6A or the rotor 4

In a fourth step, illustrated in , the damaged blade 6A is detached from the rotor 4; the slider, carrying the blade 6A, is moved horizontally to the right along C2, so that the center of gravity 6G of the damaged blade 6A substantially coincides with the axis X11 of the system.

In a fifth step, illustrated in , the mast 16 of the lifting system 11 is retracted to its retracted position P1, in which the damaged blade can be seized by the secondary crane 13, using a hook device 13C.

In a sixth step, illustrated in , the secondary crane removes the damaged blade 6A from the tool 17 and places it on the bridge 12P of the platform 12, next to the replacement blade 6B.

In the following steps, not illustrated but similar to the previous ones but in reverse order, the replacement blade 6B is fixed to the rotor 4:

- the secondary crane 13 grabs the replacement blade 6B and places it on the tool 17; Then,

- the mast 16 of the system 11 is deployed to the deployed position P2, in which the replacement blade is opposite the rotor 4; Then,

- the slider is moved in the direction of the rotor 4, the orientation of the T and the height of the supports 19A are adjusted until the replacement blade 6B is in a position such that it can be fixed to the rotor 4; Then,

- The mast 16 is brought back to its retracted position; Then,

- the platform 12 is separated from the seabed 9, then the platform floats away, carrying with it the damaged blade 6A.

A second method implemented using a system according to the invention will now be described with reference to FIGS. 7 to 9. It will be described in that it differs from the first method previously described, and in that the means for its implementation differ from those used for the implementation of the first method.

This second method allows the lifting of a heavy load 30; this load is housed in the nacelle 3 and must be removed therefrom. For the implementation of this second method, the tool 17 is equipped with winch means 17T, at least at one of its ends; to the , it is the right end of the tool which is fitted with the 17T winch means. The tool 17 is pivotally mounted relative to the mast 16, around the axis X11 of the system.

In a first step, illustrated in , the platform 12 and the lifting system 11 are arranged so that the axes X1 of the wind turbine and X11 of the system are at a second distance D2 from each other, suitable for the implementation of the second method. The mast 16 is in a second deployed position P3. In this position, the mast reaches a size greater than that reached in the deployed position P2 particularly illustrated in Figures 3 and 4; the right end of the tool is located above the nacelle 3; the winch means 17T comprise a cable 21 which extends vertically from this end to the load, to which it is attached.

In a second step, illustrated in , the load 30 is first extracted from the nacelle 3 vertically, upwards.

In a third step, illustrated in , the tool is then pivoted around the axis X11 of the device, here by one hundred and eighty degrees of angle, in order to move it away from the horizontal grip of the wind turbine 1.

In subsequent steps, not illustrated, the load 30 is then lowered onto the deck of the platform 12, in order to be evacuated.

Steps not illustrated, similar to the previous ones but in a reversed order, make it possible to set up a heavy load, brought by flotation thanks to the platform, in the nacelle.

Of course, a similar process can be implemented using the same or similar system, to move any load or equipment from the wind turbine.

We will now describe a third method implemented using a second embodiment of a system according to the invention.

In this second embodiment, the tool 17 comprises a sleeve 18 and a double arrow 20. The sleeve 18 is fixed to the upper element 16C; it is offset relative to the mast 16 of the system 11. In Figures 10 and 11, the sleeve is offset to the front of each figure. The double arrow 20 is mounted in the sleeve so as to be able to slide therein horizontally. In the figures, sliding is provided from left to right, and vice versa, of each figure. The double arrow 20 comprises two ends 20D, 20G, protruding from the sleeve, respectively to the right and to the left of the sleeve in the figures. The offset of the sleeve relative to the mast prevents the handled blade 6A from interfering with the mast 16. Each end 20D, 20G of the jib 20 carries a respective lifting cable 21, mounted on a winch. Each cable 21 carries a hook 22.

The system comprises a mast 16 and a tool 17. The mast 16 extends vertically along a system axis X11 parallel to the axis of the wind turbine X1, from the platform 12. The mast 16 comprises a lower element 16A, elements intermediate 16B and an upper element 16C. The lifting head 17 is fixed to the upper element 16C. The platform 12 includes attachment means (not shown) for a base of the mast 16. The lower element 16A includes or constitutes the base of the mast 16.

The head comprises a slider 18 and a double boom 20. The slider 18 is fixed to the upper element 16C; it is offset relative to the mast 16 of the system 11. In the figures, the slider is offset towards the front of each figure. The double arrow 20 is mounted in the slider so as to be able to slide there horizontally. In the figures, sliding is provided from left to right, and vice versa, of each figure. The double arrow 20 comprises two ends 20D, 20G, projecting from the slider, respectively to the right and to the left of the slider in the figures. The offset of the slider relative to the mast prevents the handled blade 6A from interfering with the mast 16. Each end 20D, 20G of the jib 20 carries a respective lifting cable 21, mounted on a winch. Each cable 21 carries a hook 22.

A horizontal sliding of the arrow 20 in the slider 18 makes it possible to move the blade 6A away from or bring it closer to the nose 7. A simultaneous winding or unwinding of the cables 21, at the same speed, allows a translation, respectively from bottom to top or from top to bottom, blade 6A. An independent use of the cables, makes it possible to control the inclination of the blade 6A relatively to the horizontal.

In the position illustrated in , the blade 6A to be changed rests horizontally on the hooks 22, opposite the nose 7. In this position, the blade 6A can be bolted to the nose or unbolted from the nose 7.

The system 11 can be mounted using the secondary crane 13 or a floating crane of reduced capacity and reach, compared to what is necessary to handle the blade 6A. Advantageously, as in the embodiments illustrated in FIGS. 1 to 9, at least some of the intermediate and upper elements 16B-16C of the mast 16 can be telescoped together; thus, an even smaller capacity system can be used for mounting System 11.

The elements 16A-16C can be tubular or lattice structure.

To the , the blade to be changed 6A is detached from the nose 7 and suspended from the cables 21. It is shown during descent. The system 11 is advantageously arranged on the platform 12 in order to be able to deposit the blade 6A on a dinghy boat coupled to the platform 12 or on the platform 12 itself. In the latter case, the secondary crane 13 can be provided to pick up the blade 6A from the platform 12 and place it on the tender or on a quay, if the platform was used to bring the blade 6A there.

In a reverse process, a new blade can be put in place to replace blade 6A thus removed from wind turbine 1.

With reference to the , we will now describe an improvement of the embodiment and of the method described in FIGS. 7 to 9, in that it differs therefrom.

The system illustrated here comprises a horizontal arm 31 which rigidly connects the upper element 16C with the nacelle 3. This arm makes it possible to secure the mast 16. It makes it possible to optimize the system, in particular to use a mast of lightened section, which can be more easily moved and implemented.

Instead of a single fixed arm connected to the nacelle, at least one of the intermediate elements 16B may comprise an arm mounted to slide on the post, for example on a rail provided for this purpose, so that the rigidity of the mast 2 of the wind turbine ensures the rigidity of the mast 16 of the system 11 during the deployment or retraction of the mast. This allows the use of a lighter system, as well as a lighter secondary crane, for mounting the system.

With reference to the , we will now describe a third embodiment, in that it differs from the previously described embodiments.

In this embodiment, the system comprises a base 35 fixed on the bridge 12P of the platform 12. The mast 16, in particular the lower element 16A, is rotatably mounted on the base 35. The lifting tool 17 comprises a beam horizontal 36 rigidly arranged at the top of the upper element 16C, each branch of which extends on either side of the axis X11 of the system over a distance L36. A winch 37 is fixed to the lower element 16A, so that it rotates around the axis X11 of the system, at the same time as the mast 16. A cable 38, connected to the winch, allows the lifting of a load 30. The system comprises a first cable return 39A and a second cable return 39B, for example pulleys, each disposed at a respective end of the beam 36 so that:

- Between the two transmissions, the cable is substantially horizontal;

- the cable extends vertically between the winch and the first transmission 39A; And,

- A free end of the cable extends beyond the second reference 39B, to suspend the load 30 there.

By this arrangement, the lifting loads are substantially aligned with the axis X11 of the system 11, so that the system is optimized.

Of course, the invention is not limited to the examples which have just been described. On the contrary, the invention is defined by the following claims.

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

The jack-up platform may also not be equipped with a secondary crane. In this case, a return to port can be made with the system in the retracted position and the blade resting on the lifting tool, then, a blade exchange with a port crane or another means of lifting and a return from the platform near the wind turbine for the installation of the new blade.

The system can be a tower crane equipped with a rotating jib around a vertical axis.

Also, in the second embodiment, instead of independent cables, the tool can include a spreader bar.

In the methods according to the present invention, the system and the wind turbine being fixed to the seabed, at least indirectly, they have fixed relative positions; this significantly reduces the difficulties of handling a blade. In addition, the use of a modular system makes it possible to reduce the means necessary for handling the blade. We can thus use a jack-up platform of a more common type, more available and less expensive.

The methods according to the present invention are not reserved for wind turbines of the type described. These methods can also be applied to wind turbines mounted on a barge-type platform or to wind turbines having a platform comprising rigid posts which keep it fixed to the seabed or to wind turbines mounted on gravity bases.

Also, a method according to the invention can be used for repairing a blade, the same blade being put back in place once the maintenance has been carried out. This maintenance is advantageously done on the platform 12, if it is not necessary to bring the blade back to a port.

Claims (12)

Method for handling at least one load (6, 30) on a wind turbine (1) which comprises a mast (2) rigidly fixed to a seabed (9) and a nacelle (3) carried by said mast (2), said nacelle comprising a rotor (4) having radially extending blades (6), said method being characterized by comprising steps for:
- providing a jack-up platform (12);
- immobilizing said platform close to said wind turbine (1); Then,
- mounting a lifting system (11) on said platform (12), said system comprising a mast (16) substantially vertical along an axis (X11) of the system and consisting of several elements (16A-16C) and a lifting tool ( 17) fixed on an upper element (16C);
- immobilize the nacelle (3) in a position allowing the handling of said load;
- raise said mast;
- seize the said charge;
- lower said mast; Then,
- release the movements of the nacelle and the rotor. Method for handling or fixing or removing a blade (6A, 6B) of a wind turbine (1) which comprises a mast (2) rigidly fixed to a seabed (9) and a nacelle (3) carried by said mast (2) , said nacelle comprising a rotor (4) having radially extending blades (6), said method being characterized in that it comprises steps for:
- providing a jack-up platform (12);
- immobilizing said platform close to said wind turbine (1);
- mounting a lifting system (11) on said platform (12), said system comprising a mast (16) substantially vertical along an axis (X11) of the system and consisting of several elements (16A-16C) and a lifting tool ( 17) fixed on an upper element (16C);
- immobilize the nacelle (3) in a position allowing the handling of said load;
- raise said mast;
- manipulate said blade;
- lower said mast; Then,
- release the movements of the platform. Method according to one of Claims 1 and 2, characterized in that some of the elements (16A-16C) can be telescoped together and in that the step of raising the system comprises a step of telescoping these said elements between them. Jack-up platform (12) for implementing a method according to one of Claims 1 to 3, characterized in that it comprises means for fixing a base (16A) of the lifting system (11) thereto. System for implementing a method according to one of Claims 1 to 3, characterized in that the tool is fixed substantially to the top of an upper element (16C) of the mast and forms with the said mast a shape of “T”. System according to Claim 5, characterized in that the lifting tool (17) comprises a horizontal beam (20) mounted at the top of the upper element (16C) and forming a "T" with this element, a slider (19 ) mounted to slide horizontally on said beam (20), this slider carrying seat means (19A), preferably height-adjustable, provided for resting a blade (6A, 6B) thereon. System according to Claim 6, characterized in that the beam is rotatably mounted around the axis (X11) of the system and in that the tool comprises, at one end of the said beam, winch means (17T). System according to Claim 5, characterized in that the lifting tool (17) comprises a sleeve (18) and a double jib (20) mounted to slide horizontally in the said sleeve and of which two ends (20D, 20G) each project beyond a respective side of said sleeve, each of said ends carrying a respective lifting cable (21). System according to one of Claims 5 to 8, characterized in that at least some of the elements (16A-16C) can be telescoped together. System according to one of Claims 5 to 9, characterized in that the mast (16) comprises a lower element (16A) forming a base designed to be fixed on a platform (12) according to Claim 4. System for implementing a method according to one of Claims 1 to 3, characterized in that it comprises a base (35) fixed relative to the platform (12), the mast 16 being rotatably mounted on the said base (35) around the axis (X11) of the system, the lifting tool (17) comprising a substantially horizontal beam (36) rigidly arranged at the top of the upper element (16C), a winch (37) being fixed to the lower element (16A) so that it rotates around said axis, at the same time as said mast (16), and, a cable (38) connected to the winch, the system further comprising a first cable return ( 39A) and a second cable return (39B), each disposed at a respective end of the beam (36) so that:
- Between the two transmissions, said cable is substantially horizontal;
- the cable extends vertically between the winch and the first transmission (39A); And,
- A free end of the cable extends beyond the second reference (39B) to suspend a load (30) there. System according to one of Claims 5 to 11, characterized in that it comprises arm means (31) for connecting the mast (16) of the system (11) with the mast (2) of the wind turbine, preferably at least one arm slidably mounted on said mast (2) of the wind turbine.