Taut wire system for a load management system for a wind turbine

Abstract

A load management system for a wind turbine involves: a lifting device mounted in a nacelle and connectable to a load through a lifting line; and a slew frame connectable to the load when the load is at the nacelle, the slew frame operable to change an orientation of the load when the load is connected to the slew frame and the lifting device. The load management system can further have a taut wire system. The taut wire system involves a frame mounted up-tower in a nacelle, the frame having a plurality of interconnected beams mounted on both longitudinal top beams of the nacelle, the interconnected beams having a wire connector positioned outside the nacelle transversely beyond a sidewall of the nacelle. The taut wire system further has a down-tower tensioning subsystem and at least one tensioned guide wire connected to the frame at the wire connector.

Description

[0001] TAUT WIRE SYSTEM FOR A LOAD MANAGEMENT SYSTEM FOR A WIND TURBINE

[0002] Field

[0003] This application relates to wind turbines, especially offshore wind turbines, in particular to systems and devices to assist with lifting a load, for example a wind turbine component, between down-tower and up-tower locations.

[0004] Backoround

[0005] Lifting wind turbine components up and down from the top of a tower of a wind turbine remains a difficult task, a task which is generally accomplished using lifting devices (up-tower and / or ground-based) such as cranes, winches and the like. The task is particularly difficult under conditions of high-wind and / or when the wind turbine is mounted on a fixed or floating off-shore foundation, which can cause the wind turbine and a lifted load to experience undesirable movement. Under such conditions, a load suspended by a lifting line connected to a lifting device tends to move relative to the tower while the load is being raised or lowered. Undesirable movement of the load can result in the load crashing into the tower, which could be catastrophic for either or both the load and the tower.

[0006] Guide wire systems for assisting with the lifting of wind turbine components are known, for example as described in International published application WO 2020 / 177824 published September 10, 2020 and European patent application 4015435 published June 22, 2022. Such systems suffer from a variety of problems including one or more of an inability to manage very heavy wind turbine components, an inability to manage the movement of a lifted load to different parts of a nacelle, and others.

[0007] There remains a need for systems that assist with the lifting of a load (e.g., wind turbine components) at a wind turbine, especially for a bottom fixed or floating offshore wind turbine, where the system controls the motion of the lifted load to minimize the chance that the load will contact the tower or exceed nacelle mounted lifting device capabilities during a lifting process.

[0008] Described herein in is a load management system for lifting loads at a wind turbine, the load management system comprising: a lifting device mounted in a nacelle of the wind turbine and connectable to a load through a lifting line; and, a slew frame connected to the lifting device or to another component in the nacelle, the slew frame connectable to the load when the load is at the nacelle, the slew frame operable to change an orientation of the load when the load is connected to the slew frame and the lifting device.

[0009] In some embodiments, the load management system comprises a taut wire system for controlling motion of a load being lifted between down-tower and up-tower of a wind turbine. In some embodiments, the taut wire system is installed on the wind turbine extending between a down-tower location and an up-tower location. In some embodiments, the taut wire system reduces undesirable motion of the load while the load is being lifted between the down-tower and up-tower locations. The undesirable motion may be movement in one or more of the horizontal and vertical directions.

[0010] Also described herein is a taut wire system for controlling motion of a load being lifted between down-tower and up-tower of a wind turbine, the taut wire system comprising: a taut wire frame mounted up-tower in a nacelle of the wind turbine, the taut wire frame comprising a plurality of interconnected beams mounted on both longitudinal top beams of the nacelle, at least one of the interconnected beams comprising at least one wire connector positioned outside the nacelle transversely beyond a sidewall of the nacelle; a down-tower tensioning subsystem supported on a platform or a down-tower portion of the wind turbine; and, at least one tensioned guide wire connected to the taut wire frame at the at least one wire connector, the at least one tensioned guide wire connecting the taut wire frame to the tensioning subsystem such that the at least one guide wire extends vertically down-tower without interference from the wind turbine.

[0011] Also described herein is a process for lifting a load between a down-tower location and a nacelle of a wind turbine, the process comprising providing an adapter beam connected to a face of the load, and either: engaging the adapter beam with at least one guide wire of a taut wire system installed on the wind turbine, raising the load up to the nacelle with a lifting device while the adapter beam is engaged with the at least one guide wire, disengaging the adapter beam from the at least one guide wire without disconnecting the adapter beam from the load, connecting a slew frame installed in the nacelle to the adapter beam, moving the load in the nacelle with the lifting device and re-orienting the load using the slew frame, engaging the adapter beam with at least one vertically extending guide rail installed in the nacelle and disconnecting the slew frame from the adapter beam without disconnecting the adapter beam from the load, and lowering the load while the adapter beam engages the at least one rail guide; or, engaging the adapter beam with at least one vertically extending guide rail installed in the nacelle, raising the load with a lifting device while the adapter beam engages the at least one rail guide, connecting a slew frame installed in the nacelle to the adapter beam, disengaging the adapter beam from the at least one vertically extending guide rail without disconnecting the adapter beam from the load, moving the load in the nacelle with the lifting device and re-orienting the load using the slew frame, engaging the adapter beam with at least one guide wire of a taut wire system installed on the wind turbine, disconnecting the slew frame from the adapter beam without disconnecting the adapter beam from the load, and lowering the load down from the nacelle with the lifting device while the adapter beam is engaged with the at least one guide wire.

[0012] The load management system is especially useful for lifting and otherwise managing the motion of very heavy loads, for example wind turbine components such as generators, gearboxes, main bearings, transformers and the like, during a lifting process. The load management system is especially useful for offshore wind turbines, under very windy conditions and / or in the presence of waves, swell and / or current.

[0013] In some embodiments of the load management system, slew frame comprises a single extendible strut. In some embodiments, the single telescoping strut has a hinge at a distal end thereof connectable to the load for controlling the orientation of the load.

[0014] In some embodiments of the load management system, the slew frame comprises at least two spaced-apart struts. In some embodiments, the at least two spaced-apart struts are connected together by at least one crossbar. In some embodiments, the at least two spaced-apart struts are non-extendible. In some embodiments, the slew frame comprises at least two spaced-apart extendible struts. In some embodiments, the at least two spaced- apart extendible struts comprises two telescoping struts. In some embodiments, the slew frame is mounted in the nacelle of the wind turbine, for example on the lifting device. In some embodiments, the slew frame is mounted on a lifting device located in the nacelle. In some embodiments, the slew frame is mounted on a rotatable structure in the nacelle. In some embodiments, the slew frame is mounted on a rotatable portion of a lifting device in the nacelle. In some embodiments, the slew frame rotates with a lifting device as the lifting device rotates.

[0015] In some embodiments of the load management system, at least one first actuator extends and retracts at least one of the at least two spaced-apart extendible struts. In some embodiments, the at least one first actuator comprises two first actuators. In some embodiments, actuation one the two first actuators extends and retracts one of the two telescoping struts and actuation another of the two first actuators extends and retracts another of the two telescoping struts. In some embodiments, the two first actuators are operable independently of each other. Independent extension and retraction of the two first actuators permit pivoting of the load to a number of desired orientations to accommodate different nacelle configurations and different placements of the lifting device in the nacelle.

[0016] In some embodiments of the load management system, the at least one second actuator connects one of the extendible struts to another of the extendible struts. In some embodiments, actuation of the at least second actuator assists with slewing the slew frame in a direction away from a direction in which the extendible struts extend and retract. In some embodiments, the at least one second actuator is connected to a telescoping portion of the one of the two telescoping struts and to a telescoping portion of the other of the two telescoping struts. In some embodiments, the at least one second actuator comprises a linear actuator.

[0017] In some embodiments, the extendible struts each comprise a non-moving portion and a moving portion. In some embodiments, bridging the non-moving portion and the moving portion of each extendible strut is an actuator (e.g., a linear actuator, a hydraulic cylinder or the like) whose actuation extends and retracts the strut. In some embodiments, the non-moving portion of each strut has a proximal end adapted to be connected to a rotatable portion of the lifting device. In some embodiments, the slew frame comprises a slew actuator (e.g., a linear actuator, a hydraulic cylinder or the like) connecting the moving portions of the two extendible struts together. In some embodiments, actuation of the slew actuator in tandem with one or the other of the extendible actuators causes the slew frame to rotate in a horizontal plane.

[0018] In embodiments where the slew frame has at least two extendible struts, the slew actuator may not be required to cause rotation in the horizontal plane. Extending one but not the others of the extendible struts, or extending one of the extendible struts farther than the others of the extendible struts, causes the rotation. In such embodiments, the at least two extendible struts may comprise joints, for example gimbal joints, where the extendible struts are connected to the load. Further, in some embodiments, the slew frame comprises only one extendible strut to extend and retract the slew frame without rotation in the horizontal plane.

[0019] In some embodiments, the slew frame is configured to move in several degrees of freedom, for example to translate vertically to follow a vertical motion of a hook of the lifting device when lifting the load, to translate horizontally (e.g., telescoping) to push / pull the load in a horizontal plane, and / or to rotate around a vertical axis to rotate the load around the vertical axis. In some embodiments, the load management system further comprises an adapter beam removably secured to the load. In some embodiments, the adapter beam is releasably connectable to the slew frame. In some embodiments, the adapter beam comprising a bar removably securable to a face of the load. In some embodiments, the bar comprises wire retainers connected thereto that interact with the guide wires of the taut wire system. In some embodiments, the wire retainers are on an opposite side of the bar from the load. The wire retainers hold the adapter beam between the taut guide wires while the load is being lifted to control the motion of the load to minimize the chance that the load will contact the tower of the wind turbine during the lifting process. In some embodiments, the wire retainers comprise arcuate flanges to constrain the guide wires within the wire retainers during lifting. In some embodiments, the arcuate flanges do not fully surround the guide wires, having a gap between ends of the arcuate flanges, so that the adapter beam can be readily engaged with and disengaged from the guide wires without removing the load from the adapter beam. In some embodiments, the wire retainers are removable or foldable. In some embodiments, the bar comprises rail retainers configured to engage the guide rails mounted in the nacelle. In some embodiments, the rail retainers are on the opposite side of the bar from the load. In some embodiments, the rail retainers comprise a pair of L-shaped flanges, which form a channel. In some embodiments, the L-shaped flanges protrude from the bar. In some embodiments, the L-shaped flanges are inside the bar.

[0020] In some embodiments, the load management system further comprises at least one vertically extending guide rail mounted in the nacelle. In some embodiments, the adapter beam comprises at least one rail retainer that engages the guide rail when the load is moved to the guide rail so that the load is guided by the guide rail while the load is being lifted. In some embodiments, the at least one vertically extending guide rail comprises two vertically extending guide rails. In some embodiments, the at least one vertically extending guide rail comprises a T-beam, an I-beam a beam with a U-shaped profile or a pipe. In some embodiments, the at least one vertically extending guide rail is helical. A helical guide rail automatically re-orients the load as the load is guided by the guide rail. In some embodiments, the at least one rail retainer comprises two rail retainers corresponding to the two guide rails. In some embodiments, the at least one rail retainer comprises at least one ring sized to allow passage of a pipe therethrough. In some embodiments, the at least one ring comprises at least one aperture in a perimeter thereof to pass mounting brackets of the pipe. In some embodiments of the load management system, the adapter beam comprises wire retainers connected thereto that interact with guide wires of a taut wire system while the load is being lifted between down-tower and up-tower. In some embodiments, the wire retainers are not fully enclosing the guide wires so that the adapter beam is separable from the guide wires with separating the adapter beam from the load.

[0021] In some embodiments of the load management system, the lifting device is rotatable about a vertical axis in the nacelle. In some embodiments, the lifting device comprises a crane, a winch or the like.

[0022] In some embodiments of the taut wire system, the at least one wire connector comprises at least two wire connectors. In some embodiments, the at least one guide wire comprises at least two guide wires. In some embodiments, the at least two guide wires are spaced apart longitudinally with respect to a longitudinal axis of the nacelle. In some embodiments, the at least two guide wires are substantially equidistant from the nacelle. In some embodiments, the at least one guide wire comprises fiber rope wires (e.g., Fibermax™ with only longitudinal strings) for the best performance.

[0023] In some embodiments of the taut wire system, the tensioning subsystem comprises at least one tensioning device to which the at least one guide wire is connected, In some embodiments, the at least one tensioning device is operable to pull on the at least one guide wire to tension the at least one guide wire to a tension force so that the at least one guide wire is taut between the taut wire frame and the tensioning subsystem. In some embodiments, the tensioning subsystem comprises at least one sheave through which the at least one guide wire is reeved before the at least one guide wire is connected to the at least one tensioning device. In some embodiments, the at least one tensioning device comprises at least two tensioning devices. In some embodiments, the at least one sheave comprises at least two sheaves. In some embodiments, the tensioning subsystem comprises at least two tensioning devices having different orientations. In some embodiments, the at least one tensioning device comprises a hydraulic cylinder, a pneumatic cylinder, a linear actuator or a winch. In some embodiments, the at least one tensioning device both tensions the at least one guide wire and dampens resonant vibrations of the at least one guide wire.

[0024] In some embodiments of the taut wire system, the plurality of interconnected beams comprises a quadrilateral composed of a pair of longitudinally spaced apart transverse beams connected together by a pair of transversely spaced apart longitudinal beams. In some embodiments, the quadrilateral is mounted on the longitudinal top beams of the nacelle. In some embodiments, the plurality of interconnected beams comprises at least one cantilever beam connected to the quadrilateral at another sidewall of the nacelle. In some embodiments, the at least one cantilever beam extends upwardly and transversely across the nacelle over the sidewall beyond which the at least one wire connector is positioned. In some embodiments, the at least one cantilever beam comprising the at least one wire connector. In some embodiments of the taut wire system, the plurality of interconnected beams comprises at least one vertical beam connected to and extending vertically upward from the quadrilateral to support the at least one cantilever beam from below the at least one cantilever beam. In some embodiments, the at least one vertical beam supports the at least one cantilever beam at the sidewall beyond which the at least one wire connector is positioned.

[0025] In some embodiments of the taut wire system, the at least one cantilever beam comprises a first section connected to the quadrilateral, the first section angled upwardly, transversely and inwardly into the nacelle. In some embodiments, the at least one cantilever beam comprises a second section extending transversely and horizontally from an end of the first section. In some embodiments, the at least one cantilever beam comprises a third section extending vertically upward from the second section. In some embodiments, the at least one cantilever beam comprises a fourth section extending transversely and horizontally from the third section outwardly from the sidewall beyond which the at least one wire connector is positioned proximate an end of the fourth section. In some embodiments, the at least one cantilever beam comprises at least two cantilever beams.

[0026] Each of the interconnected beams may be of any suitable cross-sectional profile, for example polygonal (e.g., rectangular, square, triangular), circular, oval and the like.

[0027] The taut wire system controls the motion of the lifted load to minimize the chance that the load will contact the tower or exceed nacelle mounted lifting device capabilities during a lifting process. Further, the taut wire system ensures that the load remains within the limits (e.g., off lead, side lead) of the lifting device. Further, the taut wire system can compensate for the angle of the nacelle frame to accommodate lifting the load from or to a level surface. Furthermore, the taut wire system can be mounted towards a rear of the nacelle to accommodate lifting wind turbine components that are further forward in the nacelle. In addition, the load management and taut wire systems are designed to permit ready human access to load connect and disconnect areas using walkways and ladders, which enhances the safety of using these systems. The systems are useful for lifting operations at any type of wind turbine, for example bottom fixed and floating offshore wind turbines. The systems are especially useful for floating offshore wind turbines.

[0028] Further features will be described or will become apparent in the course of the following detailed description. It should be understood that each feature described herein may be utilized in any combination with any one or more of the other described features, and that each feature does not necessarily rely on the presence of another feature except where evident to one of skill in the art.

[0029] Brief Description of the Drawings

[0030] For clearer understanding, preferred embodiments will now be described in detail by way of example, with reference to the accompanying drawings, in which:

[0031] Fig. 1 depicts upper and lower portions of a wind turbine having a taut wire system mounted thereon as part of a load management system for assisting with motion control of a load during a lifting process.

[0032] Fig. 2 depicts a magnified rear perspective view of a nacelle of the wind turbine of Fig. 1 showing an up-tower taut wire frame of the taut wire system shown in Fig. 1 mounted in the nacelle.

[0033] Fig. 3 depicts a magnified front perspective view of the nacelle of Fig. 2 showing the taut wire frame mounted therein.

[0034] Fig. 4 depicts the taut wire frame shown in Fig. 3.

[0035] Fig. 5 depicts another embodiment of a taut wire frame mounted in a nacelle of a wind turbine.

[0036] Fig. 6 depicts a perspective view of a down-tower tensioning subsystem of the taut wire system shown in Fig. 1.

[0037] Fig. 7A depicts other components of the load management system for a wind turbine, which assists with moving a lifted load between the taut wires of the taut wire system and a location in the nacelle of the wind turbine.

[0038] Fig. 7B depicts the other components of the load management system of Fig. 7A where a slew frame is connected to an adapter beam. Fig. 7C depicts the other components of the load management system of Fig. 7B showing the load having been moved to a different position.

[0039] Fig. 8A depicts a perspective view of the adapter beam of the load management system of Fig. 7A connected to a load.

[0040] Fig. 8B depicts a top view of Fig. 8A.

[0041] Fig. 9A depicts a perspective view of the adapter beam shown in Fig. 8A without the load connected thereto.

[0042] Fig. 9B depicts a top view of Fig. 9A.

[0043] Fig. 10A depicts a perspective view of the slew frame of the load management system of Fig. 7A.

[0044] Fig. 10B depicts an alternate perspective view of the slew frame of Fig. 10A.

[0045] Fig. 1 1 depicts a first step in a process for lifting a load up to a nacelle of a wind turbine using the load management system.

[0046] Fig. 12 depicts a second step in the process started in Fig. 11 .

[0047] Fig. 13 depicts a third step in the process started in Fig. 11 .

[0048] Fig. 14 depicts a fourth step in the process started in Fig. 11 .

[0049] Fig. 15 depicts a fifth step in the process started in Fig. 11 .

[0050] Fig. 16A depicts a sixth step in the process started in Fig. 1 1 .

[0051] Fig. 16B depicts a bottom perspective view of Fig. 16A.

[0052] Fig. 16C depicts a top view of Fig. 16A.

[0053] Fig. 16D depicts Fig. 16C without a lifting device shown.

[0054] Fig. 17A depicts a seventh step in the process started in Fig. 11 .

[0055] Fig. 17B depicts a top view of Fig. 17A without a lifting device shown.

[0056] Fig. 18A depicts the magnified rear perspective view of Fig. 2 showing an alternative embodiment of guide rails in which the guide rails are helical. Fig. 18B depicts a load being lowered on to the guide rails depicted in Fig. 18A.

[0057] Fig. 18C depicts Fig. 18B with the load lowered further down the guide rails.

[0058] Fig. 18D depicts Fig. 18B with the load lowered all the way down the guide rails.

[0059] Detailed Description

[0060] With reference to the Figures, a load management system 50 comprises various components including a lifting device 52, an adapter beam 60, a slew frame 70, at least one guide rail 51 , a landing mat 59 and a taut wire system 10.

[0061] Fig. 1 to Fig. 6 depicts the taut wire system 10, the at least one guide rail 51 and the landing mat 59 of the load management system 50. for assisting with lifting loads, for example wind turbine components, at an offshore wind turbine 1 . With reference to Fig. 1 , the wind turbine 1 comprises a tower 2 supported on a platform (not shown) and a nacelle 3 supported atop the tower 2. Mounted on the wind turbine 1 is the taut wire system 10 for assisting with motion control of a load (e.g., a wind turbine component such as a generator, a gearbox, a main bearing, a transformer or the like) during a lifting process. The taut wire system 10 comprises a taut wire frame 30 mounted up-tower in the nacelle 3, a down-tower tensioning subsystem 20 supported on the platform (or on a down-tower portion of the tower 2) and at least one guide wire 15 connecting the taut wire frame 30 to the tensioning subsystem 20. Two guide wires 15 are illustrated, however, one, two, three, four or more guide wires may be used. The two guide wires 15 are spaced apart longitudinally with respect to a longitudinal axis of the nacelle 3. The two guide wires 15 are substantially equidistant from the nacelle 3. Two guide rails 51 are illustrated, however, one, two, three, four or more guide rails may be used. The two guide rails 51 are spaced apart transversely with respect to a longitudinal axis of the nacelle 3. The landing mat 59 is located in a lay down area adjacent the tensioning subsystem 20, the landing mat 59 acting as a base for positioning a load to be lifted adjacent the taut wire system 10 and for protecting the structure of the platform from damage by equipment positioned in the lay down area.

[0062] With reference to Fig. 2, Fig. 3 and Fig. 4, the taut wire frame 30 comprises a plurality of interconnected beams mounted on both longitudinal top beams 5 of a nacelle frame 4 of the nacelle 3. The plurality of interconnected beams of the taut wire frame 30 comprises a quadrilateral composed of a pair of longitudinally spaced apart transverse beams 32 connected together by a pair of transversely spaced apart longitudinal beams 34. The quadrilateral is secured to the top beams 5 by brackets 33. The plurality of interconnected beams further comprises a pair of cantilever beams 36 connected to the quadrilateral at a sidewall 6 of the nacelle 3, which extend upwardly and transversely across the nacelle 3 over an opposite sidewall 7 of the nacelle 3 terminating at wire connectors 37, for example lugs, shackles, rings, pins or the like. Each of the cantilever beams 36 comprises: a first section connected to the quadrilateral, the first section angled upwardly, transversely and inwardly into the nacelle 3 away from the sidewall 6 of the nacelle 3; a second section extending transversely and horizontally from an end of the first section; a third section extending vertically upward from the second section; and a fourth section extending transversely and horizontally from the third section outwardly from the sidewall 7 of the nacelle 3. The wire connectors 37 are proximate ends of the fourth sections of the cantilever beams 36 and are positioned outside the nacelle 3 transversely beyond the sidewall 7 of the nacelle 3 so that the guide wires 15, which are dead end connected to the connectors 37, can extend vertically down-tower without interference from the tower 2 and with enough distance between the guide wires 15 and the tower 2 so that a load being lifted with the assistance of the taut wire system 10 does not contact the tower 2 while being lifted. The plurality of interconnected beams further comprises a pair of vertical beams 38 connected to and extending vertically upward from the quadrilateral on the side of the nacelle opposite the side of the nacelle at which cantilever beams 36 are connected to the quadrilateral. The vertical beams 38 support the cantilever beams 36 from below the cantilever beams 36. The plurality of interconnected beams further comprises a cross brace 40 connecting the cantilever beams 36 where the cantilever beams 36 are supported by the vertical beams 38. The plurality of interconnected beams further comprises first angle braces 42 connecting the second sections of cantilever beams 36 to respective third sections of the cantilever beams 36, and second angle braces 44 connecting the second sections of cantilever beams 36 to respective vertical beams 38, to provide further structural support for the cantilever beams 36 in the taut wire frame 30. The taut wire frame 30 structure utilizing support from the nacelle frame 4 on both sides of the nacelle 3 and utilizing the plurality of interconnected beams provides greater strength and support to the guide wires 15 while permitting the guide wires 15 to be tensioned with higher forces and to extend vertically downward so that the landing mat 59 can be positioned close to the tower 2 given the limited available space on an offshore wind turbine platform.

[0063] With reference to Fig. 2, Fig. 3 and Fig. 4, the guide rails 51 are mounted to a bedplate (not shown) and / or to the taut wire frame 30 and / or some other structural member inside the nacelle 3 and extend vertically upward higher than the sidewalls 6, 7 of the nacelle 3. The guide rails 51 are positioned in the nacelle 3 where the load is located or to be located. Operation of the guide rails 51 is described in more detail below. With reference to Fig. 5, an alternative embodiment of a taut wire frame 31 is depicted mounted inside the nacelle 3 of the wind turbine 1. The taut wire frame 31 bears many commonalities with the taut wire frame 30 operating in substantially the same manner as the taut wire frame 30. However, the taut wire frame 31 comprises a third cantilever beam 35 from which a third guide wire 16 extends vertically downward. The third cantilever beam 35 is longitudinally spaced apart either forward of the most forward of the cantilever beams 36 or rearward of the most rearward of the cantilever beams 36. The third cantilever beam 35 is illustrated in a more forward position. The third cantilever beam 35 is connected by extension beams 39 to one of the other cantilever beams 36 and not directly to the quadrilateral making the third cantilever beam 35 somewhat less strong, but the presence of the third cantilever beam 35 provides flexibility to help guide loads of different sizes using the same taut wire frame.

[0064] With reference to Fig. 6, the tensioning subsystem 20 comprises a solid bar 21 that can be rigidly secured down-tower to the wind turbine platform, the wind turbine tower 2 or any other structure that can immobilize the bar 21 . Connected to the bar 21 is at least one sheave 22 through which the at least one guide wire 15 is reeved. In the illustrated embodiment, the at least one sheave 22 comprises two sheaves 22, each having one of the two guide wires 15 sheaved therethrough. The tensioning subsystem 20 further comprises at least one tensioning device 23 to which the at least one guide wire 15 is connected after having passed through the at least one sheave 22. In the illustrated embodiment, the at least one tensioning device 23 comprises two tensioning devices 23, each having one of the two guide wires 15 connected thereto.

[0065] The at least one tensioning device 23 is operable to pull on the at least one guide wire 15 to tension the at least one guide wire 15 to a desired tension force so that the at least one guide wire 15 is taut between the taut wire frame 30 and the tensioning subsystem 20. In addition to tensioning the guide wire 15, the at least one tensioning device 23 can be equipped to absorb energy that the at least one guide wire 15 might acquire due to external forces acting over a length of the at least one guide wire 15. Long tensioned wires secured at both ends can be affected by external forces such as the wind and the movement of loads connected to the long tensioned wire to cause the long tensioned wire to oscillate at a harmonic frequency thereby causing the load to swing back and forth. Further, and more importantly, the wind turbine itself experiences motion due to waves, the wind turbine undergoing regular changes in inclination due to wave action. During a lifting process, the pendulum length of a lifting line of the lifting device creates a natural pendulum period that coincides with the motions of the wind turbine causing resonance of the load swing. To prevent or reduce such swinging, the tensioning device 23 can be equipped to dampen the oscillations of the at least one guide wire 15 in addition to tensioning the at least one guide wire 15. The at least one tensioning device 23 can therefore serve to provide tension to the at least one guide wire 15, adjust the tension and / or the damping value on the at least one guide wire 15 when desired and lock the tension and / or the damping value on the at least one guide wire 15 around a desired value to provide the ability to dampen oscillations of the at least one guide wire 15. Adjusting the tension and / or damping value of the at least one guide wire 15 changes the eigenfrequency of the taut wire system 30 to prevent resonance of the load swing. Different pre-tension and damping values can be applied to the at least one guide wire 15 to accommodate different motion inputs and loads to be controlled.

[0066] Some examples of suitable tensioning devices are hydraulic cylinders and pneumatic cylinders. Equipping the hydraulic cylinders with hydraulic accumulators and equipping the cylinders with accumulators permits the cylinders to dampen the oscillation of the at least one guide wire. Pressure relief valves may also be used for pressure overload protection. In the illustrated embodiment, the at least one tensioning device 23 comprises two hydraulic cylinders, one for each of the guide wires 15. In the illustrated embodiment, the guide wires are connected to ends of the cylinder rods of the hydraulic cylinders. The hydraulic cylinders are mounted on the bar so that retraction and extension of the cylinder rods are parallel to a longitudinal axis of the bar. With the guide wires connected to ends of the cylinder rods, retraction of the cylinder rods draws the guide wires taut.

[0067] The tensioning subsystem 20 further comprises at least one bumper 24, which serves to deflect a load towards the landing mat 59 as a load is lowered along the guide wires 15. In the illustrated embodiment, the at least one bumper 24 comprises two bumpers 24, one located proximate each guide wire 15. The bumpers 24 comprise studs connected to and upwardly extending from the bar 21 , the studs comprising angled upper faces 25 that contact the load and direct the load away from the bar 21 at one side of the bar 21 thereby protecting both the tensioning subsystem and the load from damage. The at least one bumper 24 also protects the tensioning subsystem 20 during the transfer of storage containers from a vessel to the floating platform. The at least one bumper 24 are also useable to assist with correct positioning of storage containers or other loads such as a gearbox or generator on the landing mat 59, the storage containers containing other components of the load management system 50.

[0068] Fig. 7A to Fig. 10B depict other components of the load management system 50 for moving loads during a lifting operation at the wind turbine 1 . The load management system further comprises the lifting device 52 (e.g., a crane, a winch or the like) comprising the lifting line 53 connectable to the load 54, which in the illustrated embodiment comprises a wind turbine generator, but can be any load, for example other wind turbine components (e.g., gearbox, main bearing, transformer and the like), and other loads. The lifting device 52 is mounted in the nacelle 3 of the wind turbine 1 and is rotatable about a vertical axis in the nacelle 3. The load management system 50 further comprises the adapter beam 60 and the slew frame 70. The adapter beam 60 is securely mountable to a face of the load 54 and is connectable to the slew frame 70. The slew frame 70 is mounted in a convenient location in the nacelle of the wind turbine, for example on the lifting device 52. The slew frame 70 is connectable to the adapter beam 60. A come-along line 55 with hoisting capability connects the slew frame 70 to the lifting device 52. As seen in Fig. 7A to Fig. 7C, the lifting device 52 is used to lift the load 54 to the slew frame 70, where the slew frame 70 is then connected to the adapter beam 60 thereby connecting the load 54 to the slew frame 70 through the adapter beam 60 (see Fig. 7B). The orientation of the load 54 is then changeable in a controlled manner by operation of the slew frame 70 as seen in Fig. 7C compared to Fig. 7B. The ability to controllably change the orientation of the load 54 permits accurate placement and removal of the load 54 in the nacelle.

[0069] Fig. 8A and Fig. 8B provide a magnified view of the adapter beam 60 mounted on a face of the load 54. Fig. 9A and Fig. 9B provide view of the adapter beam 60 alone. The adapter beam 60 comprises a bar 61 removably secured to a face of the load 54. On an opposite side of the bar 61 from the load 54, the bar 61 has wire retainers 62 connected thereto that interact with the guide wires 15 while the load 54 is being lifted between the landing mat 59 and the nacelle 3. The wire retainers 62 hold the adapter beam 60, and therefore the load 54, between the taut guide wires 15 while the load 54 is being lifted to control the motion of the load 54 to minimize the chance that the load 54 will contact the tower 2 during the lifting process. The wire retainers 62 comprise arcuate flanges to constrain the guide wires 15 within the wire retainers 62 during lifting, but the arcuate flanges do not fully surround the guide wires 15, having a gap between ends of the arcuate flanges, so that the adapter beam 60 can be readily engaged with and disengaged from the guide wires 15 without removing the load 54 from the adapter beam 60. Therefore, the load 54 together with the adapter beam 60 can be moved by the lifting device 52 to positions in the nacelle away from the guide wires 15 without having to disconnect the adapter beam 60 from the load 54.

[0070] Also on the opposite side of the bar 61 from the load 54, the bar 61 comprises rail retainers 64 configured to engage the guide rails 51 mounted in the nacelle. Each of the rail retainers 64 comprise a pair of L-shaped flanges protruding from the bar 61 , which form a channel 65. The guide rails 51 comprise I-beams or T-beams having a T-shaped flange along one side that is complementary to the channel 65 formed by the L-shaped flanges of the rail retainers 64. The load 54, having the adapter beam 60 connected thereto, can therefore be moved by the lifting device 52 from the guide wires 15 to the guide rails 51 whereupon the lifting device 52 can be operated to lower the adapter beam 60 on to the guide rails 51 so that the rail retainers 64 engage the guide rails 51 to easily position the load 54 in exactly the correct location in the nacelle 3. Conversely, the load 54 with the adapter beam 60 connected thereto can be moved from the location in the nacelle 3 to the guide wires 15 by reversing the operation.

[0071] During the lifting operation, the load 54 while being lifted vertically and moved horizontally in the nacelle 3 is usually not oriented correctly to be easily placed or removed from a proper location in the nacelle 3, especially when the load 54 is positioned at the top end of the guide wires 15 after being lifted up or in preparation for being lifted down the tower 2. To facilitate proper orientation of the load 54 in the nacelle 3, the load management system 50 also comprises the slew frame 70 for making adjustments to the orientation of the adapter beam 60, and therefore to the load 54, while the load 54 is moved in the nacelle 3. Details of the slew frame 70 are depicted in Fig. 10A and Fig. 10B.

[0072] The slew frame 70 comprises a pair of spaced-apart telescoping struts 71 connected together by crossbars 72 to form a frame. The telescoping struts 71 comprise a non-moving portion 71a and a moving portion 71 b. Bridging the non-moving portion 71a and the moving portion 71 b of each telescoping strut 71 is a telescoping actuator 76 (e.g., a linear actuator, a hydraulic cylinder or the like) whose actuation extends and retracts the telescoping strut 71. Angled braces 73 connecting the non-moving portions 71a of the telescoping struts 71 to the crossbars 72 provide extra structural integrity for the slew frame 70. The non-moving portion 71 a of each telescoping strut 71 has a proximal end 74 adapted to be connected to a rotatable portion of the lifting device 52, for example a top part of a slew bearing of the lifting device. The moving portion 71 b of each telescoping strut 71 has a distal end 75 adapted to be releasably connected to the adapter beam 60. The adapter beam 60, on the opposite side of the bar 61 from the load 54, comprises slew frame connectors 66 (e.g., lugs, rings, pins or the like) (see Fig. 8A, Fig. 8B, Fig. 9A and Fig. 9B) to which the distal ends 75 of the moving portions 71 b of the telescoping struts 71 of the slew frame 70 are releasably connectable. The releasable connection of the telescoping struts 71 to the slew frame connectors 66 permits the distal ends 75 of the telescoping struts 71 to rotate and translate with respect to the adapter beam 60 to provide some movement tolerance to the connection. In the illustrated embodiment, the distal ends 75 of the telescoping struts 71 are mounted with respective pins to the respective slew frame connectors 66. When the load 54 with the adapter beam 60 mounted thereon is at the top of the guide wires 15, the telescoping struts 71 of the slew frame 70 can be extended toward the adapter beam 60 using the telescoping actuators 76 so that the distal ends 75 can be connected to the slew frame connectors 66 thereby connecting the load 54 to the slew frame 70. Differential actuation of the telescoping actuators 76 causes the slew frame 70 to rotate in a horizontal plane, i.e. slew. With the load 54 attached to the adapter beam 60, which in turn is attached to the slew frame 70, rotation of the slew frame 70 causes a change in orientation of the load 54 (see Fig. 7B and Fig. 7C). Therefore, the adapter beam 60 together with the slew frame 70 facilitate easy and accurate movement and placement of the load 54 by the lifting device 52 in and out of the nacelle 3.

[0073] As can be seen from the description above, the adapter beam 60 is designed to engage the load 54, the taut guide wires 15, the slew frame 70 and the guide rails 51 . This single structure (i.e., the adapter beam) leads to a simple and accurate movement of a load into and out of the nacelle, and up and down the wind turbine tower with minimal effort and complication at each step in the lifting process. The adapter beam can be designed in different configurations for greatest efficiency depending on the load to be lifted.

[0074] Fig. 1 1 to Fig. 17B depict a process for lifting the load 54 up to and into the nacelle 3 of the wind turbine 1 using the load management system 50. In the illustrated embodiment, the load 54 comprises a wind turbine generator. The process can be reversed to lift the load 54 out of and down from the nacelle 3 to a base of the tower 2 of the wind turbine 1.

[0075] Fig. 11 depicts a first step in the process of lifting the load 54. With the taut wire system 10 installed on the wind turbine 1 and the adapter beam 60 connected to the load 54, the load 54 is placed on the landing mat 59 in a lay down area at the base of the tower 2 of the wind turbine 1 and the adapter beam 60 is engaged with the taut guide wires 15 at opposite ends of the load 54. The lifting line 53 of the lifting device 52 (e.g., a crane) is connected to the load 54 in preparation for lifting the load 54.

[0076] As seen in Fig. 12, the load 54 is then lifted by the lifting device 52 with the taut guide wires 15 engaged in the wire retainers 62 (see Fig. 8A and Fig. 8B) of the adapter beam 60 to ensure that the load 54 does not swing while being lifted. Taglines (not shown), e.g., human-controlled or winch-controlled, may be used in combination with the taut guide wires 15 to help control the load 54. As seen in Fig. 13, when the load 54 reaches the nacelle 3 at the top of the tower 2, the load 54 can be lifted no further while the adapter beam 60 is engaged with the guide wires 15 because the load 54 is at the top of the guide wires 15 and the taut wire frame 30 is in the way. At this point, the slew frame 70 is extended and connected to the adapter beam 60 and the guide wires 15 are disengaged from the adapter beam 60. The slew frame 70 acts to stabilize the load 54 against swinging on the lifting line 53.

[0077] As seen in Fig. 14, with the adapter beam 60 disengaged from the guide wires 15 and engaged with the slew frame 70, the lifting device 52 is operated to move the load 54 away from the taut wire frame 30 toward the guide rails 51 mounted at a rear of the nacelle 3 where the load is intended to be deposited. At the same time, the slew frame 70 is operated to change the orientation of the load 54 to begin properly aligning the adapter beam 60 and the load 54 with the guide rails 51 .

[0078] As seen in Fig. 15, the lifting device 52 moves the load 54 to the guide rails 51 with the assistance of the slew frame 70 connected to the adapter beam 60 to stabilize the load 54 during movement.

[0079] As seen in Fig. 16A to Fig. 16D, the load 54 is re-oriented by operating the slew frame 70 so that the channels 65 in the rail retainers 64 of the adapter beam 60 are at the top of and aligned with respective guide rails 51 in preparation for lowering the load 54 down to a floor 8 of the nacelle 3.

[0080] As seen in Fig. 17A to Fig. 17B, with the guide rails 51 retained in the channels 65 formed by the rail retainers 64 of the adapter beam 60, the slew frame 70 is disconnected from the adapter beam 60 and the load 54 is lowered down to the floor 8 of the nacelle 3 by the lifting device 52 with the rail retainers 64 of the adapter beam 60 retaining the guide rails 51 in the channels 65 so that the adapter beam 60 with the load 54 connected thereto slides on the guide rails 51. In this manner, the load 54 is placed in exactly the desired location in the nacelle 3. Once the load 54 is placed, the adapter beam 60 is removed from the load 54 and the guide rails 51 are dismounted from the nacelle 3.

[0081] As seen in Fig. 1 1 to Fig. 17A, the load 54 is stabilized at all times against unwanted movement during the lifting process with the load management system 50. The taut wire system 10, the slew frame 70 and the guide rails 51 stabilize the load 54 at various stages of the lifting process without the load 54 ever being not stabilized by one or more of these elements of the load management system 50. The lifting process described in Fig. 11 to Fig. 17A can be reversed to lift a load out of a nacelle and down from the nacelle to a lay down area.

[0082] Fig. 18A to Fig. 18D depicts an alternative embodiment of the load management system in which guide rails 151 comprise vertically oriented helical pipes. To accommodate the helical guide rails 151 an adapter beam 160, which is of otherwise similar construction to the adapter beam 60, comprises rail retainers 164 in the form of rings having inner diameters larger than diameters of the helical pipes. As seen in the progression from Fig. 18B to Fig. 18D, when the load 54 is first lowered (Fig. 18B) to the guide rails 151 , the rail retainers 164 engage the guide rails 151 and the load 54 is in a particular orientation. As the load 54 is lowered and the rail retainers 164 slide on the guide rails 151 captured within the rings (Fig. 18C), the load 54 changes orientation by rotating as a result of the adapter beam 160 rotating due to the helical path described by the guide rails 151. Further lowering of the load 54 to the bottom of the rail guides 151 (Fig. 18D) results in further rotation of the load 54 on the guide rails 151 so that the load 54 is properly oriented when situated in the intended position in the nacelle 3. In addition, an alternative slew frame 170 is utilized in which the slew frame 170 lacks the slew actuator, relying only on the telescoping struts and the helical guide rails 151 for managing orientation of the load 54. The process is reversed when raising the load 54 out of the nacelle 3.

[0083] The novel features will become apparent to those of skill in the art upon examination of the description. It should be understood, however, that the scope of the claims should not be limited by the embodiments but should be given the broadest interpretation consistent with the wording of the claims and the specification as a whole.

Claims

Claims:1 . A taut wire system for controlling motion of a load being lifted between down-tower and up-tower of a wind turbine, the system comprising: a taut wire frame mounted up-tower in a nacelle of the wind turbine, the taut wire frame comprising a plurality of interconnected beams mounted on both longitudinal top beams of the nacelle, at least one of the interconnected beams comprising at least one wire connector positioned outside the nacelle transversely beyond a sidewall of the nacelle; a down-tower tensioning subsystem supported on a platform or a down-tower portion of the wind turbine; and, at least one tensioned guide wire connected to the taut wire frame at the at least one wire connector, the at least one tensioned guide wire connecting the taut wire frame to the tensioning subsystem such that the at least one guide wire extends vertically downtower without interference from the wind turbine.

2. The taut wire system of claim 1 , wherein the at least one wire connector comprises at least two wire connectors and the at least one guide wire comprises at least two guide wires spaced apart longitudinally with respect to a longitudinal axis of the nacelle and substantially equidistant from the nacelle.

3. The taut wire system of claim 1 or claim 2, wherein the tensioning subsystem comprises at least one tensioning device to which the at least one guide wire is connected, the at least one tensioning device is operable to pull on the at least one guide wire to tension the at least one guide wire to a tension force so that the at least one guide wire is taut between the taut wire frame and the tensioning subsystem.

4. The taut wire system of claim 3, wherein the tensioning subsystem comprises at least one sheave through which the at least one guide wire is reeved before the at least one guide wire is connected to the at least one tensioning device.

5. The taut wire system of claim 4, wherein the at least one tensioning device comprises at least two tensioning devices and the at least one sheave comprises at least two sheaves.

6. The taut wire system of any one of claims 3 to 5, wherein the at least one tensioning device comprises a hydraulic cylinder.

7. The taut wire system of any one of claims 3 to 6, wherein the at least one tensioning device both tensions the at least one guide wire and dampens resonant vibrations of the at least one guide wire.

8. The taut wire system of any one of claims 1 to 7, wherein the plurality of interconnected beams comprises: a quadrilateral composed of a pair of longitudinally spaced apart transverse beams connected together by a pair of transversely spaced apart longitudinal beams, the quadrilateral mounted on the longitudinal top beams of the nacelle; at least one cantilever beam connected to the quadrilateral at another sidewall of the nacelle, the at least one cantilever beam extending upwardly and transversely across the nacelle over the sidewall beyond which the at least one wire connector is positioned, the at least one cantilever beam comprising the at least one wire connector; at least one vertical beam connected to and extending vertically upward from the quadrilateral to support the at least one cantilever beam from below the at least one cantilever beam at the sidewall beyond which the at least one wire connector is positioned.

9. The taut wire system of claim 8, wherein the at least one cantilever beam comprises: a first section connected to the quadrilateral, the first section angled upwardly, transversely and inwardly into the nacelle; a second section extending transversely and horizontally from an end of the first section; a third section extending vertically upward from the second section; and a fourth section extending transversely and horizontally from the third section outwardly from the sidewall beyond which the at least one wire connector is positioned proximate an end of the fourth section.

10. The taut wire system of claim 8 or claim 9, wherein the at least one cantilever beam comprises at least two cantilever beams.

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