Guiding system for replacing wind turbine blades and method of use

Abstract

The present application relates to a guide system for replacing a wind turbine blade (4) using an internal raising and lowering system fixed to a rotor (3). The guide system is characterized in that it comprises a passive and semi-rigid retaining line (5) forming a safety catenary or track for lowering the blade (4) without impingement of the blade to the tower (1) or the ground due to incident wind up to 15 m / s. A clamp (7) fixed to the end of the blade (4) slides along the holding line (5) with the horizontal movement of the blade (4). The catenary optionally has an intermediate point whose tension depends on the incident wind: the greater the wind, the greater the tension. The guidance system may be used for onshore wind turbines, floating offshore wind turbines connected to springs, and ship-assisted offshore wind turbines on a male sea.

Description

Technical Field

[0001] The blade guidance system uses passive holding lines and lifting clamps attached to the blade tips during raising and lowering maneuvers. It also describes its use for onshore and offshore wind turbines: fixed and floating, as well as wind turbines assembled using a support vessel or in port. Background Art

[0002] This guidance system is independent of the raising and lowering system covered by PCT / ES2021070488 by the same applicant.

[0003] During the assembly, replacement or repair of blades, whether or not a large crane is used, holding lines are necessary to ensure that the blades do not hit the tower due to wind action. They are also used to rotate the blades from a vertical position to a horizontal position and vice versa.

[0004] The most common holding element is a flexible element supplemented by a small crane. This flexible element is attached to the blade tip and guides it when it approaches the ground, helping it to change its position. Patents US20100139062A1 and US2015233341A1 show how to guide the blade tip with the help of a crane. Patent US20160040649A1 details how a small holding crane can include a basket to insert and support the blade tip.

[0005] It is also known how to control the movement of the blade tip due to incident wind, thereby counteracting this movement using a plurality of cables that are manually guided and held by their respective winches or pulleys. This is the case in patent US2017045030A1. Patents WO2018054440A1, WO2011086205A1, and WO2006053554A2 also show blade tips with cables and ropes attached to a hoist arranged on the ground for the purpose of holding the tip and rotating the blade.

[0006] In some of the above patents, the holding lines are the same as those used to lower the blade, and in other cases the holding lines applied to the blade tips are active systems: cables that move, wind up and / or unwind independently of the cables used to raise and lower the blade.

[0007] None of the prior art patents proposes a solution where the holding line is a semi-rigid, stationary cable that acts as a guide for the blade and enables control / rotation of the blade in very high winds. Summary of the Invention

[0008] The guidance system consists of cables that simulate metal guides or fixed rails. It is a passive and semi-rigid system, meaning it has a certain degree of flexibility.

[0009] One of the objectives of the invention is that the two guy cables form a catenary that is as rigid as possible and separated from each other by a distance that remains constant from their anchorage in the nacelle to their anchorage in the ground. This distance is equal to the width of the clamp used and wider than the blade itself.

[0010] Another object of the invention is to keep the wires independent of the lifting / lowering system.

[0011] Another object of the present invention is that the clamp connected to the blade tip elevates and engages the blade, remaining attached to the blade in the front third of the blade, thereby allowing the blade to rotate freely according to the catenary line.

[0012] Another object of the present invention is that the means for tensioning the cable and creating a catenary line (which prevents the blade tip from hitting the ground and varies in direction depending on the blade's length) is a counterweight anchored to the ground, or a metal guide anchored to the base. The cable is maintained constantly taut by an internal tensioner. The stronger the wind, the greater the tension.

[0013] The blade must also be positioned horizontally. It will first be lowered at a 30° angle through the holding wires, and then at a 90° angle. Typically, this is done using a crane, but when a crane is not required, a second practical option can be used.

[0014] The advantage of this system is that it can be assembled at incident wind speeds of 15 m / s, compared to conventional crane assemblies which only allow wind speeds of 8 to 10 m / s.

[0015] Finally, another objective is to detail the differences in the use of holding lines depending on whether the wind turbine is onshore or offshore. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Below is given a brief description of a series of drawings that serve to provide a better understanding of the invention and specifically relate to embodiments of said invention, which are provided as non-limiting examples.

[0017] Figure 1 A complete wind turbine is shown.

[0018] Figure 2 The cables deployed from the nacelle are shown.

[0019] Figure 3 Shown are weight pads used to anchor cables.

[0020] Figure 4The connection fixture and its elevation are shown.

[0021] Figure 5 The clamp anchored to the blade is shown.

[0022] Figure 6 Indicates lowering control.

[0023] Figure 7 An auxiliary crane is shown.

[0024] Figure 8 Indicates the leveling process.

[0025] Figures 9 to 16 The deployment, anchoring and tensioning of cables, raising and anchoring to a blade using a connecting clamp and lowering of the blade according to a second embodiment of the invention are shown.

[0026] Figure 17 The system is shown on a stationary offshore wind turbine assisted by an auxiliary vessel.

[0027] Figure 18 A proposed system for floating offshore wind turbines arranged alongside a pier is shown. DETAILED DESCRIPTION

[0028] like Figure 1 As shown, the wind turbine comprises a tower 1 anchored to the ground, which supports its respective rectangular nacelle 2, to which is attached at the front a rotor 3 which typically supports three blades 4. The blades to be lowered are arranged vertically parallel to the tower 1 .

[0029] Figure 2 It is shown how holding wires 5 extend from the underside front of the nacelle 2 to the base of the tower 1. These holding wires 5 are two in number and are preferably steel cables.

[0030] Figure 3 A counterweight 6 is shown, anchored to the ground and spaced sufficiently apart from the tower 1 to create a catenary or safety path that prevents blades 4 from striking the tower 1 due to incident wind. A holding wire 5 is attached to the counterweight and is tensioned to a greater or lesser degree depending on the wind speed. Instead of a counterweight, a beam connected to a foundation (not shown) can be used to hold the wire at a sufficient distance from the tower. The tensioner can be located on the counterweight 6, on a beam (not shown), or on the nacelle 2 itself.

[0031] Figure 4 The clamp 7 is shown being raised along the track formed by the holding wires 5. This raising is performed from the top of the nacelle 2 by a worker 8 pulling a rope or similar device. When the clamp 7 reaches the lower part of the blade 4, it is fixed there and the raising device is removed, as shown in FIG. Figure 5 shown.

[0032] like Figure 6 As shown, the craneless raising and lowering device 9 proposed in patent PCT / ES2021070488 and anchored inside the hub 3 comprises: an alignment device with a hoist, cables and pulleys; and a lowering device with a drumless hoist, cables and pulley assembly. This device is completely independent of the guiding system of the present invention. When the lowering device lowers the blade, the clamp slides along the safety path formed by the retainer 5, thereby preventing the incident wind from moving it out of the plane formed by the retainer 5. When the blade tip 4 reaches the ground, the clamp 7 is attached to an auxiliary element 10, such as a crane or the like. At this time, the lateral anchors of the clamp 7 are released, allowing it to slide along the path of the retainer 5, as Figure 7 shown.

[0033] Figure 8 It is shown how pulling the auxiliary element 10 lowers the blade 3 horizontally until it rests on the ground, while the lowering device 9 continues to release its corresponding cable 9'.

[0034] exist Figure 9 In the second practical embodiment shown, the retainers 5 extend from the lower front part of the nacelle 2 to the base of the tower 1 and extend beyond. The retainers 5 are two, preferably steel cables, and are anchored to the final counterweight 6 and the auxiliary anchor. In this practical embodiment, the auxiliary anchor (which can be only one) is two: one is formed by a cable 11 fixed to the base of the tower 1, and the other is formed by a cable 11 fixed to the auxiliary counterweight 6 ', as shown in FIG. Figure 10 The fixing cables 11 and the auxiliary counterweight 6 ′ can be replaced by beams (not shown) anchored to the tower base 1 .

[0035] like Figure 11 As shown, when the holding line 5 is tensioned from the base of the nacelle 2 and / or from the counterweight 6 , the pulley 12 at the end of the auxiliary anchoring cable 11 forms a rigid track with the holding line 5 at a first angle of 30° and a second angle of 60°.

[0036] Figure 12 It shows how an operator 8 raises the clamp 7 from the top of the nacelle 2 by pulling its corresponding cable 7 ′. The clamp 7 has lateral anchors so that it slides along the holder 5 and, when it reaches the pulleys 12 of the auxiliary anchors, it passes around them to continue its ascent until it is attached to the lower part of the blade 4. The pulleys 12 can be replaced by shackles that can be opened passively and / or actively to allow the clamp 7 to pass.

[0037] Figure 13The blade 4 is shown lowered thanks to the lowering device 9 arranged inside the rotor 3. As soon as the clamp 7 passes the first auxiliary anchor, the blade 4 starts to tilt, thus following the rigid path formed by the holder 5 and Figure 14 and 15 Indicated in.

[0038] like Figure 16 As shown, the blade 4 ends in a horizontal position without the need for auxiliary elements such as cranes etc. It is held by the cables 7 ′ of the lowering device 9 and by the lateral anchors of the clamp 7 which slides along the rigid path formed by the holder 5 without leaving it.

[0039] Another possible practical implementation uses a rigid beam (such as Figure 17 and 18 The cable 11 and the pulley 12 are replaced by a rigid beam shown in FIG. 1 , which extends from the bottom plate of the tower 1 and contacts one or two points of the holding wire 5, thereby forming a Figures 11 to 16 It can also be formed by one set of beams extending from the base of the tower 1 and a second set of beams further away from the base of the tower 1, the second set of beams being anchored to the same Figures 10 to 16 At the equivalent point of the auxiliary weight 6' shown.

[0040] The methods followed for using guidance systems are common regardless of whether the wind turbine is on land or offshore.

[0041] Only the auxiliary elements used to level the blades are different.

[0042] like Figure 17 As shown, the wind turbine comprises a tower 1 anchored to its respective sheath 13. The blades 4 to be lowered are arranged vertically parallel to the tower 1. A retaining wire 5 extends from the underside front of the nacelle 2 to the base of the sheath 13, creating a sufficient distance to form a catenary or safety path that prevents the blades 4 from striking the tower 1 due to incident wind. The retaining wire 5 is fixed to a beam 14 connected to the sheath 13. Semi-rigid tensioners for the retaining wires can be arranged on the beam 14 or on the nacelle 2 itself.

[0043] When the clamp 7 reaches the base of the blade 4 and secures it there, the blade is lowered. When the blade tip 4 reaches the end, the clamp 7 is attached to the ship's crane 10'. At this point, the lateral anchors on the clamp 7 are released, allowing it to slide along the path of the guy wire 5 until the blade is horizontal and rests on the auxiliary vessel 15. This option is valid for both floating and anchored offshore wind turbines.

[0044] Figure 18Several differences are shown compared to the previously described lowering method. An auxiliary crane 10 ″ is arranged on a quay 16 , and the wind turbine has the upper components, which are mounted: tower 1 , nacelle 2 , rotor 3 and transition piece or jacket 13 . The entire assembly floats close to the quay 16 . The holder 5 is fixed to a beam 14 connected to the lower part of the jacket 13 . With the help of the quay crane 10 ″, the blade 4 is arranged horizontally and guided to the quay 16 .

Claims

1. A guide system for replacing wind turbine blades, said guide system using an internal raising and lowering system (9) fixed inside the rotor (3) in order to lower the blades (4) by means of a hoist, cables and pulleys, characterised in that: Passive and semi-rigid holding lines (5) are anchored on one side to the nacelle (2) and on the other side to the ground (onshore wind turbines) and the jacket (offshore wind turbines), thereby forming a catenary or a safety path for lowering the blades (4) vertically without them hitting the tower (1), the ground or the jacket, A clamp (7) capable of being lifted from the nacelle (2) is fixed to the end of the blade (4), said clamp sliding between the holding wires (5) accompanying said clamp during operation of a raising and lowering system (9) fixed inside the rotor (3) and guiding the tip of the blade (4) away from the holding wires (5) during horizontal arrangement with the aid of an auxiliary crane (10, 10', 10") or guiding the tip of the blade not to leave the holding wires (5) during horizontal arrangement without using an auxiliary crane, The holding wire (5) forms a catenary and operates with tension provided by a tensioner arranged in the nacelle (2) or a tensioner arranged in a lower anchorage of the jacket (13) or the ground, and is independent of the raising and lowering system (9) fixed inside the rotor (3).

2. The guide system for replacing a wind turbine blade according to claim 1, wherein: The lower anchorage connecting the holding wires (5) forming the catenary is formed by a counterweight (6) anchored to the ground (onshore wind turbines) and by a plurality of beams (14) fixed to the jacket (13) (offshore wind turbines).

3. A guide system for replacing a wind turbine blade according to the preceding claims, characterized in that: At least one of the lower anchors is formed on the holder (5) by means of a cable (11) and a pulley (12), and at a point arranged on the ground: in the base of the tower (1) or in an auxiliary counterweight (6') of the tower.

4. The guide system for replacing a wind turbine blade according to claim 1, wherein: By releasing the clamp (7) from the holder (5) and using an auxiliary crane (10) for onshore wind turbines and a crane on a vessel (10') and a crane on a quay (10") for floating or fixed offshore wind turbines, the clamp is rotated along the catenary and the blade (4) is leveled, the clamp being applied in each case to the tip of the blade (4) covering the front third of the blade.

5. The guide system for replacing a wind turbine blade according to claim 1, wherein: The clamp (7) is raised and attached to the tip of the blade (4) by manual or automatic elements arranged in the nacelle (3).

6. The guide system for replacing a wind turbine blade according to claim 1, wherein: Tension is gradually applied to the holding line (5) according to the incident wind using a tensioner on the ground, the jacket (13) or the nacelle (2).

7. A method of using a guidance system for replacing a wind turbine blade, the method comprising: Passive and semi-rigid holding lines (5) are arranged from the nacelle (2), anchored on one side to the lower part of the nacelle (2) and on the other side to the ground or the jacket (13), thereby forming a catenary or a safety path for lowering the blades (4) arranged parallel to the tower (1), tensioning the holding line (5) using a tensioner arranged in the nacelle (2) or a tensioner arranged in the rearmost part of the jacket (13) or in the lower anchorage on the ground, A clamp (7) is raised from the nacelle (2) and fixed to the end or tip of the blade (4), said clamp (7) sliding between the holding wires (5) by the action of a raising and lowering system (9), which is independent of the guiding system and fixed inside the rotor (3), guiding the tip of the blade (4) without leaving the holding wires (5), And finally and optionally, attaching the clamp (7) to an auxiliary crane-type element (10, 10', 10") which pulls the tip of the blade (4), detaching the clamp (7) from the holding wire (5) and placing the blade (4) horizontally.

8. The method of using a guidance system according to claim 7, wherein: A holding line (5) separated from the tower (1) is anchored to a counterweight (6) arranged on the ground and forms a catenary or a safety passage.

9. The method of using a guidance system according to claim 7, wherein: The holding line (5) is separated from the tower (1) and is fixed with two auxiliary anchors: one is formed by a cable (11) fixed at the base of the tower (1) and the other is formed by a cable (11) fixed to an auxiliary counterweight (6'), by using the final counterweight (6) and a pulley (12) at the end of the cable (11), forming a catenary that does not require an auxiliary crane to level the blade (4).

10. The method of using a guidance system according to claim 7, wherein: The holding wires (5) are anchored to two pairs of beams attached to the base of the tower (1) and form a catenary or safety line.

11. The method of using a guidance system according to claim 7, wherein: Two retainers (5) extend from the lower front part of the nacelle (2) of a floating or offshore wind turbine installed at sea to a beam (14) arranged at the base of a jacket (13). The retaining lines (5) are held in a semi-rigid manner by actuation of tensioners in the beam (14) or in the nacelle (2) itself. The clamp (7) is raised from the nacelle (2) and, when it reaches the lower part of the blade (4), it is fixed there. The blade is lowered using a raising and lowering system (9) that is independent of the guide system. When the tip of the blade (4) reaches the end, the clamp (7) is fixed to a ship crane (10') or a quay crane (10"), the lateral anchors of the clamp (7) are released so as to slide along the safe passage of the retainers (5), and the blade (4) is arranged in a horizontal position and rests on a support vessel (15) or on the quay (16) itself.

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