Method and blade mounting device for mounting a blade of an offshore wind turbine

Abstract

In a method for mounting a blade on a horizontal axis rotating hub of an offshore wind turbine, a blade mounting device is used which is temporarily mounted on the offshore wind turbine. The device comprises a mounting member which is mounted on a foundation of the offshore wind turbine and / or mounted to a lower part of the wind turbine mast. A guide mast with a track is supported by the mounting member and extends parallel and adjacent to the wind turbine mast. A support bracket laterally supports the guide mast. The blade mounting device further comprises a blade handler assembly with a cart which is movable along the track and a blade handler comprising a blade engaging member. The blade handler is supported by the cart via an actuation assembly comprising actuators. A positioning system controls the actuators.

Description

Technical Field

[0001] This invention relates to a method and apparatus for installing blades of an offshore wind turbine having a nacelle with a horizontally oriented rotating hub arranged at the top of the wind turbine mast. The apparatus can also be used for blade removal or maintenance. Background Technology

[0002] Offshore wind turbines are typically mounted on soil-bonded foundations, such as monopile foundations or jacket foundations. The installation of blades, and potentially other components of the wind turbine, can be accomplished by a floating vessel or a so-called jack-up vessel.

[0003] In the wind power industry, floating bases for offshore wind turbines are considered the most promising solution for future wind power generation needs. However, the installation and / or removal of blades at sea is more complex. In particular, considering that wind turbine blades, now around 60 meters in length, have become quite prominent, installing blades at sea is challenging. This challenge is further amplified when installing wind turbines using floating vessels, which are subject to ocean-induced motion during installation. Imagine the floating base in, for example, deeper water, where the vessel would also float, as the depth is too great for jack-up vessels. In the case of a floating base, the wind turbine mast may be more significantly affected by sea conditions during blade installation, depending on the actual design of the base.

[0004] Large offshore wind turbines (e.g., one megawatt or several megawatts) typically have a horizontally oriented rotating hub with three blade mounts. Each blade mount usually includes a bearing that allows for variations in the blade's pitch angle. The bearing typically has a ring attached to the hub body (e.g., an outer ring) and a ring attached to the root of the rotor blade (e.g., an inner ring). Bolted connections between the blade root and the blade mount (e.g., the inner ring of the bearing) are common standard practice in the industry. T-bolt fastening arrangements are frequently used today. Bolted connections typically consist of a circular array of longitudinal bolts extending from the stern face of the blade root, with a corresponding array of bolt holes on the blade mount to receive the longitudinal bolts. Nuts are then typically tightened onto each bolt. Simultaneously inserting multiple bolts into the bolt holes requires precise alignment of the wind turbine blades relative to the blade mount, which is already challenging due to the size and weight of the rotor blades, the effects of wind, etc. Furthermore, as explained, motion can be caused by the influence of sea conditions on the vessel and / or mast.

[0005] In the industry, it is commonly known to use jack-up vessels equipped with large cranes for installing blades of offshore wind turbines with earth-bound bases. See, for example, WO2014 / 125461.

[0006] WO2012 / 002809 discloses a self-elevating vessel equipped with a lifting device configured to autonomously position wind turbine blades in a manner capable of mounting wind turbine blades onto wind turbine towers. The lifting device includes a pivoting boom structure and a positioning device that can be moved along the boom.

[0007] WO2020 / 085902 discloses a vessel for use in a floating state when installing blades on an offshore wind turbine. The vessel is equipped with a lifting device for the blades, designed for six-o'-center mounting of the wind turbine blades on a horizontally oriented rotating hub. The lifting device has a pivoting boom and a wind turbine blade root spatial orientation and support device with multiple actuators enabling multiple degrees of freedom for a movable blade root retainer. Using this lifting device, the wind turbine blades are positioned approximately vertically and below the blade mounting structure of the hub at the six-o'-center position. Summary of the Invention

[0008] The present invention aims to provide measures for improving the installation of wind turbine blades on a horizontally oriented rotating hub, which is arranged at the top of a wind turbine mast at sea. This improvement can be achieved in terms of blade installation efficiency, for example, requiring less time and / or effort, and / or within an expanded weather window (e.g., in stronger winds and / or less favorable sea conditions).

[0009] This invention provides a method for mounting blades on a horizontally axially rotating hub of an offshore wind turbine. The offshore wind turbine includes a wind turbine mast supported by a base, such as a floating base, and a nacelle having a horizontally axially rotating hub disposed at the top of the wind turbine mast.

[0010] The method uses a blade mounting device suitable for temporary installation on offshore wind turbines.

[0011] In this method, the blade mounting device is transported to the offshore wind turbine on a crane vessel equipped with a crane. The crane on the crane vessel is used to temporarily install the blade mounting device on the offshore wind turbine.

[0012] Blade mounting equipment includes mounting components installed on the base of an offshore wind turbine and / or at the bottom of the wind turbine mast.

[0013] The blade mounting device includes a guide mast that is vertically erected in the working position, wherein the guide mast is supported by mounting components and extends parallel to and adjacent to the wind turbine mast, and the guide mast has tracks.

[0014] The blade mounting device includes a support bracket that engages with the wind turbine mast and laterally supports the upright guide mast.

[0015] The blade mounting assembly further includes a blade maneuvering assembly. This assembly includes:

[0016] • A trolley that engages with the guide mast's rails and is vertically movable along the rails.

[0017] • A trolley drive mechanism, used to move the trolley along the track.

[0018] • A blade manipulator, comprising a blade engagement member configured to fix a blade relative to the blade manipulator; wherein the blade manipulator is supported by the trolley via an actuation assembly including actuators configured such that the blade manipulator can have one or more degrees of freedom relative to the trolley.

[0019] • Positioning system, which is used to control the actuator and thus the position of the blade fixed relative to the blade manipulator;

[0020] In the method, a trolley is moved to the lower blade receiving position and a blade manipulator is arranged to receive the blade in a horizontal position. A blade engagement member then secures the blade relative to the blade manipulator. The trolley is then moved along a track in the upper blade mounting position by a trolley drive. A positioning system is operated to control actuators to move the blade, secured relative to the blade manipulator, to a mounting position, for example, a vertical mounting position or another mounting position (e.g., a horizontal mounting position). When in this mounting position, the blade is attached to the horizontal axis rotating hub of the offshore wind turbine.

[0021] Advantageously, the blade manipulator assembly, including a positioning system and a trolley drive, can, for example, preferably lift and precisely position and / or align the blade manipulator and / or the blade secured by the blade manipulator with multiple degrees of freedom. This is particularly convenient for the installation of blades on offshore wind turbines. It should be understood that the blade installation device can also be used in cases where blades are removed or disassembled from an offshore wind turbine, for example, when a defective blade is to be replaced with a new one.

[0022] The blade mounting device is equipped with a blade manipulator that is adapted to move between a generally horizontal blade receiving position and a blade mounting position that can be vertical, inclined or horizontal.

[0023] The most common method is to transport blades in a horizontal orientation. Considering the size of the blades, it is advantageous to deliver blades that are also in a horizontal position or slightly off-horizontally to the blade manipulator.

[0024] A positioning system is installed for precise motion control of the blade manipulator relative to the trolley.

[0025] In the implementation scheme, at the blade mounting location, the blade manipulator is adapted to be moved to a substantially vertical position for mounting the blade to the nacelle of the offshore wind turbine, or for removing the blade from the offshore wind turbine.

[0026] In the implementation plan, the blades are installed in a completely vertical orientation.

[0027] In other embodiments, the blades are mounted at an angle, for example, at an angle of 5-40° to the vertical direction, such as between 10-25°.

[0028] In another embodiment, the blades are oriented in a substantially horizontal manner.

[0029] In the operation of the blade installation device, the guide mast is supported by an installation component mounted on the offshore wind turbine, preferably on a base or at the lower part of the mast. The lower blade receiving position of the trolley can be relatively close to the water surface. At the lower blade receiving position, the blade manipulator is able to receive the blade in a substantially horizontal position, for example, handled by one or more cranes on a crane vessel or from a blade supply vessel. The horizontal position of the blade allows it to be transferred between the blade supply vessel and the blade manipulator, with the blade's center of gravity relatively close to the water surface. This not only allows for the use of small cranes for this blade transfer, as the cranes do not need to reach the height of the nacelle. Using the blade installation device according to the invention, one or more floating vessels equipped with small and basic cranes can be used for installing and / or replacing wind turbine blades.

[0030] In this implementation, the guide mast is a telescopic mast structure. It is also conceivable that the guide mast comprises multiple components, such as two components, that are pivotable relative to each other, for example, making the mast foldable.

[0031] The blade manipulator includes a blade engagement member configured to fix the blade relative to the blade manipulator.

[0032] In the implementation scheme, the blade engagement member enables the blade maneuver to hold the blade in a substantially vertical mounting position, i.e., with the root of the blade adjacent to the nacelle, without causing the blade maneuver to move horizontally with the nacelle.

[0033] The guide mast can be much shorter than the wind turbine mast, which allows for a compact blade mount, facilitating the transport and installation of the blade mount on the offshore wind turbine.

[0034] The blade mounting device according to the invention includes a mounting component adjacent to the mast of a wind turbine, configured to be mounted on an offshore wind turbine, preferably on its substrate, such as a floating substrate or a seabed substrate, such as a jacket. The mounting component is configured to support the weight of a guide mast, blade maneuvers, and blades supported by the blade maneuvers, while the guide mast is laterally supported by the wind turbine mast via a support bracket mounted to or integrally formed with the guide mast, preferably located near the top of the guide mast. Therefore, the wind turbine mast is not used to support the weight of the blade mounting device, and the guide mast can be a compact design due to lateral support.

[0035] In one embodiment, the blade manipulator includes a plurality of spaced-apart blade engagement members adapted to engage the blade on both sides and at a distance from the blade's center of gravity. This configuration of the blade engagement members helps to stably support and secure the blade. Advantageously, the engagement members are configured to be movable, thereby allowing their positions to be adjusted to accommodate blades of different sizes.

[0036] In the implementation, the blade engagement member includes one or more root engagement members configured to engage the root end of the blade. The root engagement members may be provided optionally or in a movable manner, thus enabling their provision, particularly when dealing with large blades. The root end of the blade is an end adapted for mounting to the nacelle. The root engagement member is attributed to the precise positioning of the root end relative to the blade maneuvering device, and the positioning system thus allows the blade maneuvering device to be precisely positioned relative to the trolley, and therefore allows the blade (particularly the root end of the blade) to be precisely positioned relative to the offshore wind turbine.

[0037] In one embodiment, the blade maneuver includes a bracket having a receiving opening for receiving the blade, allowing the blade to move laterally into the bracket. In another embodiment, when the maneuver is in a substantially horizontal position, the receiving opening of the bracket faces upwards, allowing the blade to be lowered into or raised from the bracket. This facilitates transfer between the floating vessel and the blade maneuver. Advantageously, the blade engagement member is mounted to or integrally formed with the bracket.

[0038] In the implementation plan, the top of the guide mast in the installation and erection position is located below the top of the wind turbine mast, specifically below the nacelle located at the top of the wind turbine mast. The length of the guide mast should allow the blade in the upper blade mounting position to connect to the hub of the nacelle. When the blade is secured at its center by a blade manipulator, this upper blade mounting position, i.e., the upper end of the guide mast track, can be a certain distance from the nacelle, corresponding to a portion of the blade's length from the fixed portion to the blade root.

[0039] In one embodiment, the mounting components of the blade mounting device include two or more movable clamping members movable between an open position and a closed position. In the open position, the clamping members are positioned against, for example, the area around a base and / or the lower end of the mast. In the closed position, the clamping members have moved toward each other and are clamped to or around the base or the lower end of the mast. Optionally, the clamping members are interconnected.

[0040] In the implementation, the blade mounting device further includes a lifting system having a winch, cables, and a lifting boom configured to be erected relative to and supported by the top of a guide mast. The lifting boom is mounted, for example, to the top of the guide mast, near a support bracket. The lifting boom is, for example, a telescopic lifting boom. The lifting system is advantageous, for example, for the replacement or installation of gearboxes, generators, or other components. Advantageously, during use, the cables of the lifting system extend along the guide mast. This allows the lifting system to function as a trolley drive for moving a trolley along a track between a lower blade receiving position and an upper blade mounting position.

[0041] It is also conceivable that the trolley drive includes a rack and pinion drive system, or that the trolley drive includes a trolley lifting system having, for example, a winch mounted on a mounting component and associated cables guided at the top of a guide mast.

[0042] In the implementation, the actuator between the trolley and the blade manipulator includes one or more hydraulic cylinder-type outriggers. Advantageously, the hydraulic cylinder outriggers are linearly extendable and retractable outriggers, for example, having a stroke length of at least 1 meter.

[0043] In the implementation, the actuator enables the blade manipulator to have six degrees of freedom relative to the trolley. Such a six-DOF system is known, for example, as the Stewart platform system. It has six degrees of freedom, allowing movement in the X, Y, and Z directions, as well as pitch, yaw, and roll. This allows the blade manipulator to be precisely positioned, and the blades, in particular, to be aligned with the nacelle, either for installation into or removal from the nacelle.

[0044] In one embodiment, the actuation assembly of the blade manipulator includes a lifting arm with a free end, which is pivotally connected to a trolley about a horizontal lifting arm pivot axis. An actuator forms a lifting arm drive mechanism for pivoting the lifting arm. The free end of the lifting arm pivots upward relative to the trolley to the blade mounting height. The blade manipulator is pivotally connected to the free end of the lifting arm, and the blade manipulator pivots about a horizontal manipulator pivot axis parallel to the lifting arm pivot axis via an actuator forming the manipulator drive mechanism. This configuration, for example, enables the horizontal orientation of the blade to be maintained during the pivoting of the lifting arm about the lifting arm pivot axis to lift the blade.

[0045] Such a lifting arm allows the guide mast to be much shorter than the wind turbine mast, thus enabling a compact blade mount, which facilitates the transport and installation of the blade mount on the wind turbine.

[0046] Crane vessels can be monohull, catamaran, or jack-up vessels. They are equipped with cranes, and optionally multiple cranes. Attached Figure Description

[0047] The invention will be further described with reference to the accompanying drawings, in which:

[0048] Figures 1a-1c show side views of the transport and installation of the blade mounting device according to the present invention;

[0049] Figure 2 A perspective view of the blade mounting device of Figures 1a-1c, installed on a floating wind turbine in the working position, is shown. The blade mounting device supports the blade.

[0050] Figure 3 Shown in side view Figure 2 The blade mounting device supports the blade in a horizontal position;

[0051] Figure 4 It shows Figure 2 The blade mounting device, wherein the blade mounting device supports the blade in an inclined position;

[0052] Figure 5 Shown in side view Figure 2 The blade mounting device, wherein the blade mounting device supports the blade in a substantially vertical position;

[0053] Figure 6 It shows a depiction as being in such a state Figure 3 The lower blade receiving position shown and as follows Figure 5 A side view of a floating wind turbine with a blade mounting assembly at the upper blade mounting position shown.

[0054] Figures 7a and 7b show a side view and a front view of the alternative blade mounting device according to the present invention, respectively. Detailed Implementation

[0055] Figures 1a-1c and Figures 2-6 A blade mounting device 10 according to the present invention is shown.

[0056] In Figure 1a, the blade mounting device 10 is transported on the crane vessel 1 along with a plurality of blades 24. The crane vessel 1 includes a crane 2, which is a pedestal crane with a pivotable boom.

[0057] An offshore wind turbine 20 is shown, which includes a base 21 and a wind turbine mast 22 supported by the base 21.

[0058] As can be seen from Figures 1a-1c, the height of the crane 2 on the crane vessel 1 is basically less than the height of the wind turbine mast 22 of the offshore wind turbine 20. Therefore, the crane 2 on the crane vessel is not suitable for blade installation.

[0059] As can be seen in Figure 1b, how the crane 2 of the crane vessel 1 lifts and lowers the blade mounting device 10 onto the offshore wind turbine 20, and enables the blade mounting device 10 to be installed onto the base 21 of the wind turbine 20, such as a floating wind turbine or a wind turbine installed on the seabed.

[0060] The mounting component 11 of the blade mounting device is mounted on the base 21. The guide mast 12 is supported by the mounting component 11 and is configured to be parallel to and adjacent to the wind turbine mast 22.

[0061] In Figure 1b, the upper part of the guide mast will also pivot around pivot point 12'.

[0062] Figure 1c shows a fully erected guide mast 12, which is supported by mounting components 11 and extends parallel to and adjacent to the wind turbine mast 22.

[0063] In order to move the blade mounting device 10 shown in Figure 1c to the location shown in Figure 1c Figures 2-5 The working position shown will have a support bracket 14 installed at the upper end of the guide mast 12 to engage the wind turbine mast 22 and laterally support the guide mast 12 in an upright position.

[0064] An optional lifting system 40 is provided on the upper part of the guide mast 12.

[0065] Figures 3-5 The following diagram shows the subsequent working position of the blade mounting device 10 according to the present invention.

[0066] As shown in Figures 1a-1c, the blade mounting device 10 is configured for transport on a crane vessel and is suitable for installation onto and removal from the base 21 of the offshore wind turbine 20. Therefore, when it is necessary to install wind turbine blades, or to replace one or more blades, the blade mounting device 10 can be temporarily mounted on the wind turbine base to move the blades into and out of their positions where they can be installed into the wind turbine nacelle.

[0067] The blade mounting device 10 includes a mounting component 11, a guide mast 12, a support bracket 14, a blade manipulator assembly 30, and a trolley drive device 36 (in Figure 6 (See in the middle).

[0068] Mounting component 11 is configured to be mounted on the base of an offshore wind turbine. Preferably, the mounting component is mounted to the base of the wind turbine, for example, at a flange on the wind turbine mast, using the flange to mount the wind turbine to the base.

[0069] Once the mounting component 11 is installed, it provides support for the guide mast 12 and allows the guide mast to stand upright on the mounting component adjacent to the mast of the wind turbine 20.

[0070] A support bracket 14, which is installed on or integrated with the guide mast 12, is located at the top of the guide mast and engages with the wind turbine mast 22 to provide lateral support to the guide mast.

[0071] The guide mast has a track 13 for guiding the blade maneuver assembly 30 vertically along a portion of the wind turbine mast 22. The blade maneuver assembly 30 is adapted to be movable along the track 13.

[0072] The blade manipulator assembly 30 includes a trolley 31, a blade manipulator 32, and a positioning system 35.

[0073] The trolley 31 is adapted to engage the track 13 and is movable along the track, thereby enabling the blade manipulator assembly 30 to move up and down along the guide mast 12.

[0074] The blade manipulator 32 is supported by a trolley 31 via a plurality of actuators 33, which enable the blade manipulator to have multiple degrees of freedom relative to the trolley. The blade manipulator 32 includes a blade engagement member 34 configured to fix the blade relative to the blade manipulator.

[0075] The positioning system 35 is configured to control a plurality of actuators 33, and thus control the position of the blade manipulator relative to the trolley.

[0076] The trolley drive unit 36 ​​is configured to cause the trolley 31 to move along the track 13. Figure 3 The lower blade receiving position Pr and shown Figure 5 The upper blade mounting position Pi shown is moved between these two positions. Figure 6 It is shown in the side view.

[0077] The blade manipulator 32 is adapted to be moved to a horizontal position from the lower blade receiving position Pr for receiving the blade 24 in the horizontal position. This is in Figure 3 and Figure 6 As can be seen in the text.

[0078] The blade maneuver is further adapted to be moved to a vertical position at the upper blade mounting position Pi for mounting blade 24 to the nacelle 23 of the offshore wind turbine. This is in Figure 5 and Figure 6 As can be seen in the text.

[0079] It should be noted that, in the implementation scheme, when in the blade mounting position, the blade can be supported at an angle or tilt relative to the vertical direction, within the range of 0-45°. In the specific implementation shown, the blade manipulator is configured to support the blade within the range of 10-20°.

[0080] Figure 4 The image shows blade 24 supported by blade manipulator assembly 30 in a slightly angled mounting position. By enabling the blade manipulator to support the blade in this substantially vertical position, the guide mast can be mounted on the side of the wind turbine rather than in front of it, while still supporting the blade in a mounting position that allows it to be installed into the nacelle in front of the wind turbine.

[0081] Furthermore, the blade maneuvering assembly configured to engage the blade at or near its center of gravity and to support the blade in a substantially vertical position allows the guide mast to extend only along a portion of the wind turbine mast. Thus, in the exemplary embodiment shown, the top tip 12a of the guide mast 12 in its mounted and erected position is located below the top tip of the wind turbine mast 22, particularly below the nacelle 23 located at the top of the wind turbine mast.

[0082] In the exemplary embodiment shown, the blade mounting device 10 further includes an optional lifting system 40 adapted to replace components from the nacelle of the wind turbine, such as for installing or replacing the gearbox or generator of the wind turbine.

[0083] The lifting system 40 includes a winch 41, a cable 42, and a boom 43. The boom is telescopic, meaning it is configured to stand upright relative to the top 12a of the guide mast 12 and is supported by the base 21 via the guide mast. Therefore, the lifting system allows the mast to not extend into or above the nacelle of the offshore wind turbine.

[0084] The blade mounting device 30 enables a method for installing or maintaining a wind turbine 20, particularly for replacing wind turbine blades. The process of moving the blades to the mounting position is as follows: Figures 2-4 As shown.

[0085] Prior to the blade installation process, a crane vessel transports the blade installation assembly 10 (which preferably has blades, such as blades to be exchanged with blades of an offshore wind turbine) to the offshore wind turbine. In an embodiment, the crane vessel is also a blade supply vessel, i.e., a vessel that provides the blades to be installed and will transport the blades to be removed from the wind turbine.

[0086] The process of installing blade 24 is further provided by mounting the blade mounting device 10 on the offshore wind turbine 20, as shown in Figures 1a-1c. This installation process includes mounting the mounting component 11 of the blade mounting device on the base 21 of the offshore wind turbine 20, and setting a guide mast in an upright position on the mounting component, wherein the blade maneuvering assembly is engaged by rails.

[0087] Preferably, the crane of the lifting vessel used to transport the blade installation assembly is used to install the blade installation assembly onto the offshore wind turbine. Preferably, the guide mast of the blade installation assembly is configured to be erected without using the crane of the lifting vessel. In one embodiment, the mast is a telescopic mast. Alternatively, the mast may be hinged to the installation component and erected by extension or using an internal drive mechanism. Alternatively, the guide mast may comprise multiple components and be self-supporting, such as a self-supporting tower crane.

[0088] Once the blade installation device is installed on the offshore wind turbine, it can be used to move the blades in their installation location. The blade installation process includes:

[0089] - Operate the positioning system of the blade manipulator to move the blade manipulator to the horizontal blade receiving position, such as Figure 2 As shown;

[0090] - Operate the crane vessel to deliver the horizontally positioned blades to the blade manipulator;

[0091] - Operate the blade engagement member to fix the blade relative to the blade manipulator; and

[0092] - The trolley drive and positioning system operate the blade manipulator to move the blade manipulator from the horizontal lower blade receiving position to the upper, essentially vertical blade mounting position, such as... Figure 4 As shown.

[0093] Figures 7a and 7b show an alternative embodiment of the blade mounting device 100 according to the invention, which is mounted to the base 21 of an offshore wind turbine 20, which further includes a wind turbine mast 22 supported by the base.

[0094] The blade mounting device 100 includes a mounting component 111, which is mounted on the base 21 of the offshore wind turbine.

[0095] The guide mast 112 is erected in the working position, wherein the guide mast is supported by the mounting component 111 and is parallel to and adjacent to the wind turbine mast 22.

[0096] The guide mast 112 has tracks not shown in detail. A support bracket 114 is mounted to the upper end of the guide mast 112 and engages with the wind turbine mast 22, and laterally supports the upright guide mast 112.

[0097] The blade maneuver assembly 130 is movable along the guide mast, as indicated by reference numerals 130' and 130” in Figures 7a and 7b.

[0098] The blade manipulator assembly 130 includes a trolley 131 that engages a track and is movable along the track via a trolley drive mechanism, such as that discussed herein.

[0099] The blade manipulator assembly 130 further includes a blade manipulator 132, which includes a blade engagement member (not shown in detail) configured to fix the blade relative to the blade manipulator.

[0100] The blade manipulator assembly 130 further includes an actuation assembly with actuators configured to enable the blade manipulator 132 to have one or more degrees of freedom relative to the trolley 131.

[0101] Here, the actuation component of the blade manipulator assembly includes a lifting arm 121 having a free end 122, which is pivotally connected to the trolley 131 about a horizontal lifting arm pivot axis 126.

[0102] In the example, after pivoting, the lifting arm's angle with the horizontal plane is between 30 and 80 degrees, for example, between 40 and 60 degrees, or 45-50 degrees. In the example, when the lifting arm is receiving the blade, and therefore before pivoting upwards to lift the blade, the angle with the horizontal plane is between -30 and -80 degrees, for example, between -40 and -60 degrees, or 45 degrees.

[0103] At the opposite end, the lifting arm 121 is provided with a counterweight 123 to counteract the torque exerted by the blade to be held relative to the connection between the lifting arm and the trolley. This counterweight has the effect of shifting the center of gravity of the lifting arm toward the lifting arm pivot axis. Thus, the lever arm of the torque exerted relative to the pivot axis is reduced, thereby reducing the torque itself. This can benefit the load distribution of the guide mast, especially any bending stress.

[0104] The free end 122 of the lifting arm pivots relative to the trolley 131, for example, to the mounting height of the blade 1040. An actuator (not shown) between the trolley and the lifting arm forms the lifting arm drive mechanism.

[0105] The blade manipulator 132 is pivotally connected to the free end 122 of the lifting arm, and the blade manipulator pivots about a horizontal manipulator pivot axis 127 parallel to the lifting arm pivot axis 126 via an actuator forming a manipulator drive (not shown).

[0106] A positioning system is provided to control the lifting arm drive and the manipulator drive, thereby controlling the position of the blade 1040 fixed by the blade manipulator 132 relative to the trolley 131.

[0107] Not shown is a trolley drive mechanism for moving the trolley along a track between the lower blade receiving position (where the blade manipulator assembly is indicated by 130') and the upper blade mounting position (where the blade manipulator assembly is indicated by 130"). In the lower blade receiving position, the blade manipulator 132 is moved to a horizontal position for receiving the blade 1040, which is in a horizontal position. In this embodiment, at the upper blade mounting position, the blade manipulator is also in a horizontal mounting position for mounting the blade 1040 to the nacelle 23 of the offshore wind turbine.

[0108] The pivoting of the lifting arm 121, in conjunction with the vertical movement of the trolley 131 and thus the lifting arm 121, enables the controlled upward movement of the horizontally oriented blades, while utilizing the stability of the guide mast 112 relative to the wind turbine. Therefore, when lifting the blades, their movement is restricted to following the movement of the free end of the lifting arm 121, as the blades are effectively secured to the lifting arm. This contrasts with lifting the blades by suspending them on lifting cables (e.g., using a large crane on a ship as in the prior art), where practice has shown that blades are susceptible to excessive movement, such as excessive movement caused by wind and / or ship motion.

[0109] Figures 7a and 7b show the blade moving in a vertical plane parallel to and reaching the rear of the plane of motion of the lifting arm 121. In a suitable embodiment, the plane of the blade is close to the plane of the lifting arm 121, which reduces the lever arm of the force exerted on the guide mast 112 by the weight of the blade, since the blade is held relatively close to the guide mast.

[0110] In this embodiment, the lifting arm is shaped such that after the free end of the lifting arm 121 is moved upward to the installation height, the free end of the lifting arm, and thus the rotor blades fixedly held therein, can extend above the top of the guide mast 112. Therefore, the lifting arm 121 then functions as an extension above the guide mast 112, thus advantageously requiring a smaller height for the guide mast.

[0111] In the implementation, the method further includes aligning the blade with the hub connector of the blade hub (exactly) before blade installation. For example, in blade installation at the hub, the blade is aligned to achieve alignment between the bolts and bolt holes at the blade root. In the example, this is achieved by actuating one or more alignment actuators to move the blade. This alignment mechanism can be integrated with a lifting arm and / or a blade manipulator, such as a bracket that accommodates the blade during installation. For example, the alignment mechanism is capable of alignment in any one or more directions.

[0112] In one embodiment, the blade manipulator 132 includes a bracket configured to receive a blade (e.g., support a horizontally oriented blade from below, or clamp a blade from above) and configured to hold the blade horizontally.

[0113] In one embodiment, the manipulator 132 includes a bracket releasable from the lifting arm and having a connector for securing the bracket to the lifting arm 121. In another embodiment, the bracket includes an attachment portion for suspending the bracket from a crane (e.g., from a crane hook) (e.g., via one or more slings). This enables a method in which a blade is first lifted by a crane engaged with the bracket, the blade being horizontally secured and held in the bracket. For example, a blade is transferred in this manner from a supply vessel or a crane vessel to an already installed blade mounting device. This bracket, along with the blade, is then transferred by the crane and secured to a connector at the free end of the lifting arm via its connector. The crane can then be released from the bracket. Therefore, for this transfer from a ship crane to the lifting arm, it is not necessary to remove the blade from the bracket.

Claims

1. A method for mounting blades on a horizontally axially rotating hub of an offshore wind turbine, said offshore wind turbine comprising a wind turbine mast supported by a base and a nacelle having a horizontally axially rotating hub disposed at the top of the wind turbine mast. This includes blade mounting devices suitable for temporary installation on offshore wind turbines. The blade installation device is transported to the offshore wind turbine on a crane vessel equipped with a crane. The crane on the aforementioned crane vessel is used to temporarily install the blade mounting device on the offshore wind turbine. The blade mounting device includes mounting components installed on the base of the offshore wind turbine and / or at the lower part of the wind turbine mast. The blade mounting device includes a guide mast erected vertically in the working position, the guide mast being supported by mounting components and extending parallel to and adjacent to the wind turbine mast, the guide mast having rails. The blade mounting device includes a support bracket that engages with the wind turbine mast and laterally supports the upright guide mast. The blade mounting device further includes a blade manipulator assembly, the blade manipulator assembly comprising: - A trolley that engages with the guide mast's rails and is capable of moving vertically along the rails. - A trolley drive mechanism, used to move the trolley along the track. - A blade manipulator comprising a blade engagement member configured to fix a blade relative to the blade manipulator; wherein the blade manipulator is supported by the trolley via an actuation assembly including an actuator configured such that the blade manipulator can have one or more degrees of freedom relative to the trolley. - A positioning system for controlling the actuator and thus the position of the blade fixed relative to the blade manipulator; The trolley is moved to the lower blade receiving position and the blade manipulator is arranged to receive the blade in a horizontal position, wherein the blade engagement member fixes the blade relative to the blade manipulator. Furthermore, the trolley then moves along the track at the upper blade mounting position via a trolley drive, and a positioning system is operated to control the actuator to move the blade, fixed relative to the blade manipulator, to the mounting position. Furthermore, the blades located at the aforementioned installation position are attached to the horizontal axis rotating hub of the offshore wind turbine. The blade mounting device further includes a lifting system having a winch, cables and a lifting boom configured to be erected relative to the top of a guide mast and supported by a base via the guide mast.

2. The method according to claim 1, wherein, The actuator enables the blade manipulator to have six degrees of freedom relative to the trolley.

3. The method according to claim 1, wherein, During use, the cables of the lifting system extend along the guide mast, thereby enabling the lifting system to act as a trolley drive device for moving the trolley along the track between the lower blade receiving position and the upper blade mounting position.

4. The method according to claim 1, wherein, The installation position is horizontal, and the actuation component of the blade manipulator assembly includes a lifting arm with a free end, the lifting arm being pivotally connected to the trolley about a horizontal lifting arm pivot axis, wherein the actuator forms a lifting arm drive for pivoting the lifting arm, wherein the blade manipulator is pivotally connected to the free end of the lifting arm about a horizontal manipulator pivot axis extending parallel to the lifting arm pivot axis, wherein the actuator forms a manipulator drive, wherein the actuator is controlled such that the blade remains horizontally oriented during the pivoting of the lifting arm about the lifting arm pivot axis to lift the blade.

5. The method according to claim 1, wherein, The top of the guide mast, in its installed and erected position, is below the top of the wind turbine mast.

6. The method of claim 1, wherein the lifting system is used for changing components from the nacelle of a wind turbine.

7. A blade mounting device configured for temporary installation on an offshore wind turbine for mounting blades on a horizontally axial rotating hub of the offshore wind turbine, said offshore wind turbine comprising a wind turbine mast supported by a base and a nacelle having a horizontally axial rotating hub disposed at the top of the wind turbine mast. The blade mounting device can be transported to the offshore wind turbine on a crane vessel. The blade mounting device includes mounting components installed on the base of the offshore wind turbine and / or at the lower part of the wind turbine mast. The blade mounting device includes a guide mast erected vertically in the working position, the guide mast being supported by mounting components and extending parallel to and adjacent to the wind turbine mast, the guide mast having rails. The blade mounting device includes a support bracket that engages with the wind turbine mast and laterally supports the upright guide mast. The blade mounting device further includes a blade manipulator assembly, the blade manipulator assembly comprising: - A trolley that engages with the guide mast's rails and is capable of moving vertically along the rails. - A trolley drive mechanism, used to move the trolley along the track. - A blade manipulator comprising a blade engagement member configured to fix a blade relative to the blade manipulator; wherein the blade manipulator is supported by the trolley via an actuation assembly including an actuator configured such that the blade manipulator can have one or more degrees of freedom relative to the trolley. - A positioning system for controlling the actuator and thus the position of the blade fixed relative to the blade manipulator; The trolley is configured to be moved to the lower blade receiving position, and the blade manipulator is configured to receive the blade in a horizontal position. The blade engagement member is configured to fix the blade relative to the blade manipulator. Furthermore, the trolley is movable along a track at the upper blade mounting position via a trolley drive, and the positioning system is configured to be operated to control an actuator to move the blade, fixed relative to the blade manipulator, to the mounting position, thereby enabling the blade in the mounting position to be attached to the horizontal axis rotating hub of the offshore wind turbine. The blade mounting device further includes a lifting system having a winch, cables and a lifting boom configured to be erected relative to the top of a guide mast and supported by a base via the guide mast.

8. The blade mounting device according to claim 7, wherein, The actuator enables the blade manipulator to have six degrees of freedom relative to the trolley.

9. The blade mounting device according to claim 7, wherein, The lifting boom is installed at the top of the guide mast.

10. The blade mounting device according to claim 7 or 8, wherein, The installation position is horizontal, and the actuation component of the blade manipulator assembly includes a lifting arm with a free end, the lifting arm being pivotally connected to the trolley about a horizontal lifting arm pivot axis, wherein the actuator forms a lifting arm drive for pivoting the lifting arm, wherein the blade manipulator is pivotally connected to the free end of the lifting arm about a horizontal manipulator pivot axis extending parallel to the lifting arm pivot axis, wherein the actuator forms a manipulator drive, wherein the actuator is controlled such that the blade remains horizontally oriented during the pivoting of the lifting arm about the lifting arm pivot axis to lift the blade.

11. The blade mounting device according to claim 7, wherein, The guide mast is configured such that the top of the guide mast in the installation and erection position is below the top of the wind turbine mast.

12. The blade mounting device according to claim 7, wherein, During use, the cables of the lifting system extend along the guide mast, thereby enabling the lifting system to act as a trolley drive device for moving the trolley along the track between the lower blade receiving position and the upper blade mounting position.

13. The blade mounting device according to claim 7, wherein, The crane boom is installed near the support bracket.

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