Offshore floating intervention platform having a lifting tower with a position compensation device, related assembly and method - Patents.com

Abstract

The intervention platform (10) comprises at least one wind turbine equipment lifting tower (100) with at least one lifting unit (110A, 110B), the lifting tower (100) including a mast (112), a wind turbine equipment elevator (114) configured to move vertically along the mast (112) between a lower loading / unloading position and at least one upper intervention position, and a lifting actuator (116) configured to move the wind turbine equipment elevator (114) between the lower unloading / loading position and the upper intervention position. The lifting unit (110A, 110B) comprises at least one position compensation device (118) configured to be actuated in the loading / unloading position and / or in the intervention position to compensate for a local vertical displacement between the intervention platform (10) and the wind turbine platform when the intervention platform (10) is docked to the wind turbine platform.

Description

[Technical field]

[0001] The present invention relates to an offshore floating intervention platform intended to dock with a floating offshore wind turbine platform and to carry out installation and / or maintenance interventions, comprising: a floating base having at least one lower surface intended to be immersed in a body of water; at least one wind turbine equipment lifting tower having at least one lifting unit, Mast and a wind turbine equipment elevator configured to move vertically along the mast between a lower loading / unloading position and at least one upper intervention position; and a lifting actuator configured to move a wind turbine equipment elevator between a lower unloading / loading position and at least one upper intervention position.

[0002] Such an intervention platform is particularly adapted to carry out installation and / or maintenance operations in offshore wind farms located in waters deeper than 60 m.

[0003] Installation and maintenance of wind turbines can be carried out using offshore platforms such as the fixed base platform disclosed in EP 2275340. Such systems are particularly adapted for shallow waters.

[0004] However, 80 percent of the offshore wind resource potential lies in waters deeper than 60 m, making traditional subsea technologies economically unfeasible or practical. To harness this potential, floater designs are being developed that can facilitate larger turbines with nominal power outputs of 12 MW or more.

[0005] In such locations, the wind turbine mast is held by a floating base that is anchored to the bottom of the body of water by anchor lines. An example of a floater has a floating base with several floating columns connected to each other by pontoons and / or trusses. The mast may extend from the top of one of the columns.

[0006] The floaters used to hold wind turbines imply more difficult operating and maintenance (O&M) conditions for the wind turbines, requiring new operating and maintenance strategies and techniques.

[0007] In particular, floating wind turbine platforms are exposed to offshore conditions including wind, currents, and swell that affect the stability of the equipment supported by the platform.

[0008] One object of the present invention is to provide an offshore intervention platform that is particularly adapted for wind farms located in deep waters where installation and maintenance operations are difficult to carry out, especially due to offshore conditions such as wind, currents and swells.

[0009] To this end, the subject of the invention is an offshore floating intervention platform of the above mentioned type, characterized in that at least one lifting unit comprises at least one position compensation device configured to be activated in the loading / unloading position and / or in at least one intervention position in order to compensate for local vertical displacements between the offshore floating intervention platform and the floating offshore wind turbine platform when the offshore floating intervention platform is docked to the floating offshore wind turbine platform.

[0010] The offshore floating intervention platform according to the invention has the following characteristics, taken alone or according to any technically feasible combination: the position compensation device comprises at least one controller of the lifting actuators configured to control the lifting actuators to generate a vertical compensating movement of the equipment elevator in response to a local vertical displacement between the offshore floating intervention platform and the floating offshore wind turbine platform; the position compensation device comprises at least one sensor configured to provide data representative of a local vertical displacement between the offshore floating intervention platform and the floating offshore wind turbine platform, and the controller is configured to receive the data representative of the local vertical displacement from the sensor; the equipment elevator comprises a boom arm projecting from the mast and a grab cradle carried by the boom arm, the grab cradle defining at least one wind turbine equipment housing defining a wind turbine equipment storage axis; -The boom arm is telescopic and the grab cradle is movable away from the mast by telescopic deployment of the boom arm; the grab cradle is configured to translate along the boom arm; The grab cradle comprises a lateral displacer configured to move the wind turbine equipment held in the housing along the housing axis, The grab cradle has a rotary displacer configured to rotate the wind turbine equipment held in the housing about an equipment housing axis; the lifting unit comprises an additional position compensation device mounted between the boom arm and the grab cradle, the additional position compensation device being configured to be activated in the unloading / loading position and / or in the at least one intervention position in order to compensate for local displacements between the offshore floating intervention platform and the floating offshore wind turbine platform when the offshore floating intervention platform is docked to the floating offshore wind turbine platform; the equipment lifting tower comprises at least two lifting units, each lifting unit comprising a mast, an equipment elevator configured to move vertically along the mast, and a lifting actuator configured to actuate the movement of the equipment elevator, the lifting actuators of the two lifting units being independently operable; the masts of the lifting units have parallel axes or at least one mast of one lifting unit has an axis that is inclined with respect to the axis of the mast of another lifting unit; The lifting actuator comprises a rack and pinion mechanism, a hydraulic mechanism, a pneumatic mechanism, or a winch mechanism; the at least one lifting unit is configured to surround the wind turbine equipment and comprises at least one cleaning unit configured to move along the wind turbine equipment and / or the at least one lifting unit is configured to surround the wind turbine equipment and comprises at least one reinforcement unit configured to move along the wind turbine equipment to mechanically reinforce the wind turbine equipment, The cleaning unit and / or reinforcement unit may comprise one or more of: a jaw capable of surrounding the wind turbine element; a connection to a movement mechanism of the cleaning unit and / or reinforcement unit along the wind turbine element; and an arm connecting an upper part of the jaw to the connection.

[0011] The invention also relates to an assembly comprising a floating offshore wind turbine platform and an offshore floating intervention as defined above, removably docked to the floating offshore wind turbine platform.

[0012] The present invention also provides - docking an offshore floating intervention platform as defined above to a floating offshore wind turbine platform; - placing a wind turbine equipment elevator in one of a lower unloading / loading position or at least one upper intervention position; - activating a position compensation device at the loading / unloading position or at least one intervention position to compensate for a local vertical displacement between the offshore floating intervention platform and the floating offshore wind turbine platform; - performing an installation and / or maintenance intervention on a wind turbine of a floating offshore wind turbine platform.

[0013] The intervention method according to the invention has the following characteristics, taken alone or according to any technically feasible combination: The intervention method may comprise one or more of the steps of: moving the elevator between a lower unloading / loading position and at least one intervention position, and the position compensation device is stopped during the displacement of the elevator between the lower unloading / loading position and the at least one intervention position.

[0014] The present invention also relates to an offshore floating intervention platform intended to dock with a floating offshore wind turbine platform and to perform installation and / or maintenance interventions, comprising: a floating base having at least one lower surface intended to be immersed in a body of water; at least one wind turbine equipment lifting unit having a wind turbine equipment carrier carried by the floating base and configured to move along the wind turbine equipment, The at least one lifting unit comprises at least one cleaning unit configured to surround the wind turbine equipment, the cleaning unit being connected to a wind turbine equipment carrier moving along the wind turbine equipment, and / or the at least one lifting unit comprises at least one stiffening unit configured to surround the wind turbine equipment, the cleaning unit being connected to a wind turbine equipment carrier moving along the wind turbine equipment to mechanically stiffen the wind turbine equipment.

[0015] The offshore floating intervention platform may have one or more of the characteristics described above or the following characteristics: the washing unit is associated with a separate runoff water collector configured to be positioned at a lower free end of the wind turbine equipment when the wind turbine equipment is positioned vertically; the runoff collector is connected to a runoff treatment system.

[0016] The present invention also provides an offshore wind turbine platform comprising: a floating foundation having at least one lower surface intended to be immersed in a body of water; at least one wind turbine; at least one wind turbine equipment lifting unit having a wind turbine equipment carrier carried by the floating base and configured to move along the wind turbine equipment, at least one washing unit configured to surround the wind turbine equipment, the washing unit being connected to a wind turbine equipment carrier that moves along the wind turbine equipment; and / or The present invention relates to an offshore wind turbine platform featuring at least one reinforcement unit configured to surround the wind turbine equipment, the cleaning unit being connected to a wind turbine equipment carrier that moves along the wind turbine equipment to mechanically reinforce the wind turbine equipment.

[0017] An offshore wind turbine platform may have one or more of the characteristics described above or the following characteristics: the washing unit is associated with a separate runoff water collector configured to be positioned at a lower free end of the wind turbine equipment when the wind turbine equipment is positioned vertically; the runoff collector is connected to a runoff treatment system. [Brief description of the drawings]

[0018] The invention will be better understood on reading the following description, given purely by way of example and made with reference to the following drawings, in which:

[0019] [Figure 1] FIG. 1 is a schematic perspective view of a floating offshore wind turbine platform floating on a body of water. [Diagram 2] FIG. 2 is a partial perspective view of an offshore floating intervention platform according to the present invention docked to the floating offshore wind turbine platform of FIG. 1; [Diagram 3] FIG. 2 is a schematic horizontal cross-section of the floating base of the offshore floating intervention platform and the floating foundation of the floating offshore wind turbine platform when the floating base of the offshore floating intervention platform and the floating foundation of the floating offshore wind turbine platform are connected; [Figure 4] FIG. 4 is a side view of the assembly of FIG. 3 during a first step of removing the wind turbine blade from the wind turbine, with the lifting tower elevator in the upper intervention position. [Diagram 5] FIG. 5 is a view similar to FIG. 4, showing the lifting tower elevator in the lower unloading / loading position. [Figure 6] FIG. 1 is a schematic perspective view of a lifting tower of an offshore floating intervention platform according to the invention; [Figure 7] FIG. 7 is a side view of a detail of FIG. 6. [Figure 8] FIG. 1 is a schematic side view of an offshore floating intervention platform equipped with a wind turbine equipment washing unit and / or augmentation units. [Figure 9] FIG. 2 is a schematic perspective view of a cleaning unit. [Figure 10] FIG. 2 is a schematic perspective view of a reinforcing unit.

[0020] A first offshore floating intervention platform 10 according to the invention is shown in particular in FIGS.

[0021] The intervention platform 10 floats on a body of water 12. The intervention platform 10 according to the invention is intended to carry out installation and / or maintenance interventions on at least one floating offshore wind turbine platform 14, shown in Figure 1 and partially in Figure 2.

[0022] A wind turbine platform 14 is disposed on the surface of a body of water 12, for example in an offshore wind farm.

[0023] The body of water 12 in the vicinity of the offshore wind turbine platform 14 has a depth of more than 50 metres, typically comprised between 60m and 3000m.

[0024] The body of water 12 may be, for example, an ocean, a sea, a lake, and / or a river.

[0025] With reference to FIG. 1 , the wind turbine platform 14 includes a floating foundation 16 , an anchor assembly 17 that anchors the floating foundation 16 to a bottom 18 of the body of water 12 , and a wind turbine 20 supported by the floating foundation 16 .

[0026] In this embodiment, the floating foundation 16 is a semi-submersible platform. It comprises at least three floating columns 22, frame elements 24 connecting the floating columns 22, and potentially a deck (not shown).

[0027] The frame elements 24 here comprise lower pontoons 26A connecting each pair of adjacent floating columns 22 at the bottom of the columns 22, upper pontoons 26B connecting each pair of adjacent floating columns 22 at the top of the columns 22, and truss members 28 connecting the sides of each column 22 to the centre of the lower pontoons 26A.

[0028] The floating support 22 extends vertically. The floating support 22 has a buoyant volume that provides a floating buoyancy to the floating foundation 16. The buoyancy is adapted to allow the floating foundation 16 to be partially submerged in the body of water 12.

[0029] The anchor assembly 17 comprises a number of anchor lines 30 connecting each strut 22 to the bottom 18 of the body of water 12. In the example of Figure 1, each floating strut 22 is connected to at least one anchor line 30, preferentially two to four anchor lines 30.

[0030] Thus, the wind turbine platform 14 is fixed in a horizontal position within the body of water 12 .

[0031] The wind turbine 20 classically comprises a mast 32, a nacelle 34 rotatably mounted on top of the mast 32, and a rotor 36 rotatably mounted to the nacelle 34, preferentially about a horizontal axis.

[0032] The rotor 36 includes a central hub 38 and blades 40 that project radially from the central hub 38 and are reversibly secured to the hub 38 .

[0033] The mast 32 is here fixed to the top of the floating column 22 coaxially with the axis of the floating column 22 .

[0034] The floating support 22 and advantageously the lower pontoons 26A define an underside 42 of the wind turbine platform 14, below which the intervention platform 10 can dock.

[0035] The floating offshore intervention platform 10 is configured to be moved on the surface of the body of water 12 so as to be in the vicinity of the wind turbine platform 14. It is configured to be docked and secured to the wind turbine platform 14 during intervention.

[0036] Preferably, when the intervention platform 10 is docked to the wind turbine platform 14, the relative motion between the intervention platform 10 and the wind turbine platform 14 at 100m-150m above the water surface is less than 1.5m in x, y and z directions for water conditions with significant wave height Hs=2.5m and wave period 8 seconds. The term "significant wave height" means the characteristic height of random waves in sea conditions.

[0037] The intervention may be, for example, the installation of a wind turbine equipment and / or the maintenance of the wind turbine equipment. In particular, the wind turbine equipment may be a blade 40 and the intervention may be the installation of a blade 40, the maintenance of a blade 40 or the replacement of a blade 40.

[0038] Other interventions regarding the nacelle 34 or mast 32 are also within the scope of interventions that can be performed using the intervention platform 10.

[0039] 2 , the intervention platform 10 has a floating base 46 on which is mounted a deck 47. It has a system 48 configured to removably dock to the wind turbine platform 14, and a wind turbine intervention system 50 carried on the deck 47 and configured to access wind turbine equipment and perform intervention on the wind turbine 20.

[0040] The floating base 46 is advantageously similar to the floating foundation 16 of the wind turbine platform 14 .

[0041] It comprises at least three floating columns 52 , frame elements 54 connecting the floating columns 52 , and potentially a deck 47 .

[0042] The frame element 54 here comprises lower pontoons 56A connecting each pair of adjacent floating columns 52 at the bottom of the columns 52, and upper pontoons 56B connecting each pair of adjacent floating columns 52 at the top of the floating columns 52. The frame element 54 further comprises truss members 58 connecting the sides of each column 22 to the center of the lower pontoons 26A.

[0043] The floating support 52 extends vertically. The floating support 52 has a buoyant volume that provides buoyancy to the floating base 46. The buoyancy is adapted to allow the floating base 46 to be partially submerged in the body of water 12.

[0044] The floating support columns 52 and / or lower pontoons 56 A define a lower surface 60 of the intervention platform 10 that is completely submerged in the body of water 12 .

[0045] Deck 47 potentially holds accommodation 62 for personnel and a helicopter landing pad 64 for transporting personnel to the platform.

[0046] In accordance with the present invention, the docking system 48 comprises at least one heave plate 70 and a ballasting / de-ballasting unit 72 for controlling the vertical position of the at least one heave plate 70 .

[0047] Advantageously, the docking system 48 further comprises at least one contact arm 74 protruding from the floating base 46 towards the wind turbine platform 14 , a propeller 76 and at least one mooring device 78 .

[0048] The docking system 48 includes at least one heave plate 70 configured to protrude horizontally from the floating base 46 for application below the underside 42 of the wind turbine platform 14 .

[0049] In the example of FIG. 2, the docking system 48 comprises at least two heave plates 70 configured to protrude from the same side of the floating base 46, in particular configured to protrude from two adjacent floating columns 52 of the floating base 46.

[0050] In the example of FIG. 2, each heave plate 70 is configured to protrude from the lower surface 60 below the floating column 52 .

[0051] Each heave plate 70 defines an upper contact surface 80 with the lower surface 42 of the wind turbine platform 14 .

[0052] The area of ​​the upper contact surface 80 is preferably greater than 5%, especially greater than 10% of the area of ​​the lower surface 60 of the floating column 52 .

[0053] The upper contact surface 80 is advantageously equipped with an anchoring arrangement 82 , such as a friction pad or a suction device, configured to secure the upper surface 82 to the underside 42 of the wind turbine platform 14 .

[0054] In a preferred embodiment, each heave plate 70 is deployable between a retracted position located below the lower surface 60, e.g., below the lower pontoon 56 and / or below the floating column 52, and a deployed extended position applied below the floating foundation 16.

[0055] The heave plate 70 is for example rotatable about a vertical axis or telescopic. The heave plate 70 is advantageously equipped with actuators 83, such as side thrusters or a water jet system, and a locking system 83A.

[0056] The actuator 83 is configured to apply side thrust or water pressure to move the heave plate 70 between the retracted and deployed positions. It is also configured to provide suction to the suction device of the upper contact surface 80, if present.

[0057] The locking system 83A is configured to selectively lock the heave plate 70 in at least the retracted and deployed positions.

[0058] The ballast / de-ballast unit 72 comprises at least one ballast containing volume 84 and a ballast controller 86 configured to control the amount of ballast contained in the ballast containing volume 84 .

[0059] At rest, the ballast storage volume is at least partially filled with a gas, such as air, and is arranged, for example, within the floating columns 52 and / or within the frame elements 54.

[0060] The ballast here is formed of water from the body of water 12. The ballast controller 86 comprises at least one pump configured to pump ballast in and out of the ballast storage volume to regulate the amount of ballast 84 contained within the ballast storage volume.

[0061] Thus, the ballast controller 86 is configured to control the draft of the floating base 46 between a lower position, in which each heave plate 70 is configured to pass below the lower surface 42 of the wind turbine platform 14, and a fixed position, in which the upper surface 80 of the heave plate 70 is applied below the lower surface 42 of the wind turbine platform 14. In the fixed position, the upper surface 80 advantageously exerts an upward force on the lower surface 42.

[0062] Each contact arm 74 is configured to protrude from the floating column 52 to contact and advantageously connect to the floating foundation 16 , and in particular to a floating column 22 of the floating foundation 16 .

[0063] Each contact arm 74 has at least one free end 88 equipped with a connection device, such as a magnetic connection device, a mechanical connection device, and / or a suction connection device.

[0064] In the example of FIG. 2, each floating strut 52 of the floating base 46 is equipped with at least one contact arm 74 arranged above the heave plate 70, preferentially two contact arms 74 arranged above the heave plate 70.

[0065] Advantageously, each contact arm 74 is deployable from the floating support 52 from a stowed configuration to an extended configuration.

[0066] In a variant, the contact arm 74 is a bumper with or without a connecting device (attraction, magnetic, mechanical).

[0067] In the example shown in FIG. 2, each contact arm 74 is also vertically movably mounted on the floating support 52 for adjusting its vertical position between an upward dry position above the water surface and a downward submerged position below the water surface.

[0068] The propellers 76 are, for example, thrusters. They are attached below the lower surface 60, for example at the bottom of the floating columns 52. They are preferentially rotatable about a vertical axis below the lower surface 60, for example through an angular range of 360°. The propellers 76 are configured to horizontally displace each floating column 52 and / or the entire floating base 46 over the body of water 12.

[0069] Advantageously, the propeller 76 is retractable within the floating base 46 , and in particular within the floating mast 52 .

[0070] The mooring equipment 78 comprises at least one mooring line configured to be deployed towards the wind turbine platform 14 and at least one mooring winch configured to pull the mooring line to provide further fixation of the floating base 46 of the intervention platform 10 on the floating foundation 16 of the wind turbine platform 14.

[0071] The intervention platform 10 preferentially comprises a control room / wheelhouse (not shown) with radar, radio communication and a navigation controller including dynamic positioning, in particular for controlling the propellers 74. The control room also contains at least one control unit for monitoring and remotely controlling the functional systems of the intervention platform 10, such as the docking system 48 and / or the wind turbine intervention system 50.

[0072] The intervention platform 10 also comprises a power generation system, advantageously with low or no emissions, for generating electrical power, and a battery power bank for storing electrical power.

[0073] The power generation system runs on low emission fuels such as, for example, hydrogen, ammonia, or biofuels or liquefied natural gas.

[0074] It is also possible to provide battery power only, which is then periodically recharged by connecting to the wind farm power grid at a dedicated buoy, a substation, or when connected to the floating offshore wind turbine platform 14 or other power generating source, typically a support or standby vessel.

[0075] The batteries of the battery power bank may be sized only for transportation between wind turbine platforms 14 and for connection to the power grid for charging with a maximum autonomy of, for example, less than 10 km, e.g., about 1 km to 2 km.

[0076] As shown in Figures 4 to 7, the wind turbine intervention system 50 comprises a wind turbine equipment lifting tower 100. Advantageously, it comprises a wind turbine equipment housing 102 (see Figure 2) and at least one crane 104 (see Figure 4) for transporting wind turbine equipment between the wind turbine equipment housing 102 and the wind turbine equipment lifting tower 100.

[0077] In the examples shown in Figures 4 and 5, as well as Figures 6 and 7, the lifting tower 100 comprises at least one lifting unit 110A, 110B, each of which has a mast 112, an elevator 114 movably mounted along the mast 112, and a lifting actuator 116 for moving the elevator 114 between a lower unloading / loading position and at least one upper intervention position. The lifting tower 100 comprises at least one truss 120 connecting the mast 112 of one lifting unit 110A to the mast 112 of another lifting unit 110B.

[0078] According to the present invention, each lifting unit 110A, 110B is equipped with a position compensation device 118 (see Figures 6 and 7) for compensating for variations in the vertical position between the floating foundation 16 of the wind turbine platform 14 and the floating base 46 of the intervention platform 10 after the intervention platform 10 is docked to the wind turbine platform 14.

[0079] Each mast 112 extends upwardly from the deck 47. The mast 112 of at least one of the lifting units 110A, 110B extends along a vertical axis.

[0080] In the example of Figures 4 and 5, at least one mast 112 of a lifting unit 110A extends vertically and at least one mast 112 of another lifting unit 110B extends at an angle to the vertical axis. The lifting tower 110 has an A-shape. In the example of Figures 6 and 7, both masts 112 extend vertically. The lifting tower 110 has an H-shape.

[0081] In these examples, each mast 112 comprises an open framework. The masts 112 are fixed on the deck 47. In other examples, the masts 112 are deployable masts that telescopically deploy from the deck 47.

[0082] As shown in FIGS. 6 and 7, the elevator 114 of each mast 112 includes a boom arm 130 and a grab cradle 132 supported by the boom arm 130 .

[0083] 6, the boom arm 130 protrudes horizontally from the mast 112. It is movably mounted on the mast 112 along the axis of the mast 112, for example via rollers. The boom arm 130 follows, for example, a guide 134 provided on the mast 112.

[0084] In this example, the boom arm 130 has a fixed length from the mast 112. In a variant not shown, the boom arm 130 is extendable, for example telescopically.

[0085] The grab cradle 132 is movably mounted on the boom arm 130 along an axis E-E' perpendicular to the axis of the mast 112. It is mounted, for example, on rollers that are guided on the boom arm 130.

[0086] In variations in which the boom arm 130 is deployable, the grab cradle 132 is movable away from the mast 112 during deployment of the boom arm 130.

[0087] 7, the grab cradle 132 comprises a C-shaped member defining at its center an open central housing 138 intended to house wind turbine equipment. The central housing 138 defines a wind turbine equipment housing axis F-F' which in this example extends perpendicular to the boom arm axis E-E'.

[0088] The grab cradle 132 further comprises a wind turbine equipment lateral displacer 140 and a wind turbine equipment rotational displacer 142 .

[0089] Lateral displacer 140 may comprise, for example, rollers or tracks configured to displace the wind turbine equipment contained within housing 138 along wind turbine equipment containment axis F-F'.

[0090] The rotary displacer 142 also includes rollers and / or tracks that may be common to the rollers and / or tracks of the lateral displacer 140 .

[0091] The rotary displacer 142 is configured to rotate the wind turbine equipment within the housing 138 about a wind turbine equipment containment axis F-F'.

[0092] Each lifting unit 110A, 110B is therefore configured to independently lift the wind turbine equipment stored in the housing 138 of the grab cradle 132 along a vertical axis, move the wind turbine equipment away from the mast 112 along the boom arm axis E-E', and also displace the wind turbine equipment along the storage axis F-F' via the lateral displacer 140. It is further configured to locally rotate the wind turbine equipment stored in the housing 138 about the storage axis F-F'.

[0093] Furthermore, since the lifting units 110A, 110B are operable independently of each other, the grab cradles 132 are configured to be placed in different horizontal and vertical positions. Thus, by setting the grab cradles 132 at different heights, it is possible to tilt the wind turbine equipment housed in each housing 138 with respect to an axis parallel to the boom arm axis E-E'. It is also possible to tilt the wind turbine equipment housed in each housing 138 with respect to a vertical axis by placing the grab cradles 132 of the lifting units 110A, 110B at different longitudinal positions away from the mast 112.

[0094] It is therefore very easy to adjust the angle of connection of the wind turbine equipment to the wind turbine 20 when installing or replacing the wind turbine equipment.

[0095] In an advantageous embodiment, the grab cradle 132 has an air cushion to hold the wind turbine equipment within the grab cradle 132. The air cushion prevents damage to the wind turbine equipment and provides additional adjustability, motion compensation, and motion damping.

[0096] The lifting actuator 116 may comprise, for example, a rack and pinion mechanism, a hydraulic mechanism, a pneumatic mechanism, or a winch operating mechanism to control the vertical displacement of the boom arm 130, the horizontal displacement of the grab cradle 132, and / or control the lateral displacer 140 or the rotational displacer 142.

[0097] The position compensation device 118 includes at least one sensor 150 configured to determine data representative of a vertical displacement between the floating foundation 16 of the wind turbine platform 14 and the floating base 46 of the intervention platform 10 when the floating base 46 is docked on the floating foundation 16.

[0098] The position compensation device 118 further comprises a controller 152 configured to control the lifting actuator 116 to compensate for vertical displacement between the floating foundation 16 and the floating base 46 .

[0099] The sensors 150 may include, for example, optical sensors, mechanical sensors, accelerometers, GPS, etc. The sensors may be located on either or each of the floating foundation 16 and the floating base 46.

[0100] The sensor 150 is configured to provide data representative of vertical and possibly other horizontal displacements, the data being available at at least one intervention height, and preferably at multiple intervention heights.

[0101] The controller 152 comprises, for example, a computer having a processor and a memory with software configured to execute a control loop to calculate control commands for the lifting actuator 116 in response to data representative of the vertical displacement measured by the sensor 150. In an alternative, the computer comprises a field programmable gate array or other dedicated integrated circuit.

[0102] A method of intervention on a wind turbine platform 14 using the intervention platform 10 according to the present invention will now be described.

[0103] First, the intervention platform 10 approaches the wind turbine platform 14 using the propellers 76. This approach is controlled by dynamic positioning that positions the floating struts 52 of the floating base 46 at a distance from the floating struts 22 of the floating foundation 16 without colliding with the anchor lines 30 of the anchor assemblies 17.

[0104] The contact arm 74 is then actuated. The contact arm 74, which is in its upper dry position, is lowered to its lower wet position. If deployable, the contact arm 74 deploys and brings its free end 88 into contact with the floating columns 22 of the floating foundation 16. The free end 88 is connected to the floating columns 22 of the floating foundation 16 by a connection device, if available, so that the two floating columns 52 of the floating base 46 are each fixed to the two respective floating columns 22 of the floating foundation 16 by at least two connection points.

[0105] In alternative embodiments, fewer connection points or connection points at other locations on the floating foundation 16 may be provided.

[0106] The mooring equipment 78, propellers 76, and / or hydraulic arms are then used to pull the floating foundation 16 and the floating base 46 together.

[0107] The heave plate 70 beneath the floating base 46 of the intervention platform 10 is then positioned beneath the underside 42 of the floating foundation 16 , and in particular beneath the floating columns 22 .

[0108] When the heave plates 70 are deployable, they are deployed away from the floating base 46 to protrude towards and below the floating foundation 16, for example by rotation or telescopic deployment provided by the actuators 83. They are then locked in the deployed position by the locking system 83A.

[0109] If necessary, the draft of the floating base 46 can be adjusted by the ballast controller 86 to allow the heave plate 70 to be freely positioned below the lower surface 42 .

[0110] When the heave plate 70 is positioned beneath the lower surface 42, and in particular beneath the floating strut 22, the ballast controller 86 removes ballast from the floating base 46. This reduces the draft of the floating base 46 and applies the upper surface 80 of the heave plate 70 to the lower surface 42, exerting an upward force on the lower surface 42.

[0111] If present, anchoring devices 82 on upper surface 80 are actuated to connect to lower surface 42 by vacuum / hydrostatic pressure, by suction, mechanically, and / or magnetically.

[0112] The floating foundation 16 and floating base 46 behave as a single body as possible, which helps to reduce any relative motion at nacelle height.

[0113] In this case, the intervention method comprises installation or maintenance work on the wind turbine 20 .

[0114] Next, disassembly and replacement of the wind turbine equipment will be described.

[0115] Prior to engagement of the wind turbine platform 14 , the wind turbine equipment is loaded into storage 102 of the intervention platform 10 using a crane 104 from a wind turbine equipment transport ship or wind turbine equipment transport barge.

[0116] Initially, the elevators 114 of each lifting unit 110A, 110B are aligned with and raised to their respective installation positions, and the lifting actuators 116 move the boom arms 130, grab cradles 132, lateral displacers 140, and / or rotational displacers 142 to place the wind turbine equipment within the housing 138.

[0117] When the grab cradle is in the vicinity of the wind turbine equipment, the position compensation device 118 is energized. The sensor 150 detects potential vertical displacement between the floating foundation 16 of the wind turbine platform 14 and the floating base 46 of the intervention platform 10. The sensor 150 provides data representative of the vertical displacement, and possibly other horizontal displacement, to a controller 152.

[0118] At each instant in time, the controller 152 calculates a control command for the lifting actuator 116 in response to data representative of the vertical displacement measured by the sensor 150 by executing a control loop, and provides the control command to the lifting actuator 116 .

[0119] The lifting actuator 116 then moves the elevator 114 in response to a control command to compensate for the vertical displacement between the floating foundation 16 and the floating base 46 .

[0120] The grad cradle 132 securely latches onto the wind turbine equipment. If the equipment is a blade 40, the blade connection nuts are removed from the blade connection bolts.

[0121] The grab cradle 132 is then moved along the boom arm 130 to shift the wind turbine equipment away from the wind turbine 20. The position compensation device 118 is de-energized.

[0122] The elevators 114 are then moved down to their unloading / loading positions. The wind turbine equipment is then moved by the crane 104 into open space within the storage 102.

[0123] The new wind turbine equipment is removed from storage 102 and positioned on elevator 114. Elevator 114 is raised to an installation position, for example in nacelle 34. Again, position compensation device 118 is energized as described above.

[0124] The grab cradles 132 are then individually positioned to place the wind turbine equipment in the correct position and orientation for assembly on the wind turbine 20 .

[0125] This adjustment is facilitated by the independent operation of each lifting unit 110A, 110B, providing vertical translation of the boom arm 130 along the mast 112, horizontal translation of the grab cradle 132 along the boom arm 130, and additional degrees of translational and rotational freedom using the lateral displacer 140 and rotational displacer 142.

[0126] If the wind turbine equipment is a blade 40, the grab cradle 132 aligns the blade bolts with the nacelle holes and shifts the new blade into the nacelle 34. The blade connection nuts are installed on the bolts.

[0127] Once the wind turbine equipment is in position, the grab cradle 132 unlatches from the wind turbine equipment and is lowered and cleared, and the position compensation device 118 is de-energized.

[0128] The previous steps can then be repeated to install or replace additional equipment as needed.

[0129] Once the intervention is completed, the intervention platform 10 disconnects from the wind turbine platform 14 .

[0130] In the above example, the anchoring equipment 82 is shut down and the ballast controller 86 increases the draft of the floating base 46 to detach the heave plate 70 from the lower surface 32. The mooring equipment 78 and contact arms 74 are disconnected from the floating foundation 16.

[0131] The propellers 76 are then energized to move the intervention platform 10 away from the wind turbine platform 16 towards a transport vessel and / or for docking with another wind turbine platform 16 .

[0132] The intervention platform 10 according to the invention is therefore configured to perform self-propelled and low-emission operations, including installation and maintenance, in deep-sea wind farms with a floating wind turbine platform 16. The similar operating characteristics as the wind turbine platform 16 allow safe and easy operations in the wind farm to support inspection, maintenance, repair operations and replacement of blades and turbines (gears, rotors, transformers, etc.).

[0133] Particularly when equipped with the position compensation device 118, the lifting tower 100 of the intervention platform 10 allows adaptive and accurate positioning of the wind turbine equipment to assemble and / or disassemble it from the wind turbine 20 in a safe and easy manner, even if the wind turbine 20 is held by a floating foundation 16 rather than by a fixed base system.

[0134] Thus, the intervention platform 10 is particularly adapted for deeper water intervention.

[0135] In a variant, an additional vertical and / or horizontal position compensation device is provided between the boom arm 130 and the grab cradle 132 to further compensate for the relative displacement between the intervention platform 10 and the wind turbine platform 14 when the intervention platform 10 is docked on the wind turbine platform 14.

[0136] In the example of Figures 8 and 9, at least one lifting unit 110A, 110B includes a mobile washing unit 160a.

[0137] The cleaning unit 160a comprises a robotic arm 163 having one or more links with rotational degrees of freedom and one or more arm sections that can be extended in length and have features that allow the cleaning unit to move up and down.

[0138] The washing unit 160a also includes a connection 162 that may be movably mounted on the tower mast 112, such as on the elevator 114, or alternatively, may be mounted to a mobile crane having a long reach arm that may be positioned on either the floating base 46 or the floating foundation 16.

[0139] Another option is that the washing unit 160a is mounted on the wind turbine 20 itself via a system configured to move up and down the wind turbine 20.

[0140] The washing unit 160a further comprises jaws 161 capable of encircling a wind turbine equipment such as a blade 40 by means of an opening and closing mechanism.

[0141] 9, within jaws 161, cleaning unit 160a advantageously includes water spray and soap nozzles 165, hot air dryers 166, rubber blades or scrubs 167, visualization / inspection tools 168 including lights, and / or runoff collectors 169. Runoff collectors 169, if present, allow for cleaning of wind turbine equipment in a horizontal position as well as collection of debris (e.g., soap particles, paint, etc.).

[0142] The washing unit 160a also has hoses 164a, 164b for the supply of cold and hot fresh water, respectively, and for the discharge of water and / or debris.

[0143] The scrubbing unit 160a is preferably associated with a separate runoff water collector 161b positioned at the blade free end when the blade 40 is positioned vertically.

[0144] The runoff collector 161b is connected to a runoff treatment system 171 having a filter and a treatment unit with a filter. Thus, pollutants are not released into the water body 12 and wildlife is avoided from ingesting small blade particles. The treated water is collected and reused and waste is safely disposed of or collected and transported to land for further treatment.

[0145] In a preferred operation of the cleaning unit 160a, the blade 40 is positioned vertically. The lower free end of the blade 40 is placed in the runoff water collector 161b. The jaws 161 are then opened and lifted around the blade 40, inserting the blade 40 into the jaws 161. The jaws 161 are then closed and the cleaning unit 160a is moved along the blade 40.

[0146] A visualization / inspection tool 168, including a water spray and soap nozzle 165, a hot air dryer 166, a rubber blade or scrub 167, and / or a light, is then activated and moves vertically along the blade 40 to clean its exterior surface.

[0147] The runoff water sprayed onto the blade 40 in the jaws 161 flows down along the blade 40 until it reaches the blade free end. It is then collected in the runoff water collector 161b and transported to the runoff water treatment system 171.

[0148] In the example of FIG. 10, at least one lifting unit 110A, 110B comprises a mobile wind turbine reinforcement unit 160b.

[0149] The reinforcement unit 160b is similar in structure to the cleaning unit 160a and has a jaw 161 attached to a robotic arm 163 and is movable along the lifting units 110A, 110B and / or the mast 112 of the wind turbine 20.

[0150] The reinforcement unit 160b is capable of dealing with mechanical damage (such as cracks) to the wind turbine equipment, here the blade 40, and advantageously allowing the wind turbine equipment to self-heal.

[0151] The reinforcement unit 160b is configured to apply heat (via electricity, friction, and / or chemical reaction) locally to areas having mechanical damage so that the materials (e.g., resins and / or coatings) of the wind turbine equipment can self-heal.

[0152] The reinforcement unit 160b includes at least one heating source 170 configured to apply heat locally and concentratedly to a given area within the jaws 161. The heating source 170 is configured to increase the temperature of the given area, for example, to between 80° C. and 250° C. The heated material (e.g., a resin or coating) can plastically deform to fill and fix mechanical damage, such as cracks.

[0153] In an alternative or complementary embodiment, the reinforcement unit 160b comprises a localized resin and / or coating dispenser configured to heat and dispense a resin and / or coating to fill the mechanical damage.

[0154] In that case, the reinforcement unit 160b may have a vacuum, pressure or vibration applicator 171 to help the resin or coating enter the mechanical damage. The jaws 161 are then advantageously equipped with air cushions (not shown) at their edges so as to be able to define an airtight housing that seals around the blade.

[0155] In an alternative or complementary embodiment, the reinforcement unit 160b comprises at least one tool 172 for drilling holes and making small cuts in the wind turbine equipment.

[0156] In a variant, the docking system 48 of the intervention platform 10 does not comprise at least one heave plate 70 configured to protrude laterally from the floating base 46 for docking to the wind turbine platform 16 .

Claims

1. An offshore floating intervention platform (10) intended to dock with a floating offshore wind turbine platform (14) to perform installation and / or maintenance interventions, comprising: a floating base (46) having at least one lower surface (60) intended to be immersed in a body of water (12); - at least one wind turbine equipment lifting tower (100) having at least one lifting unit (110A, 110B), Mast (112), a wind turbine equipment elevator (114) configured to move vertically along said mast (112) between a lower loading / unloading position and at least one upper intervention position; a lifting actuator (116) configured to move the wind turbine equipment elevator (114) between the lower unloading / loading position and the at least one upper intervention position, 1. An offshore floating intervention platform (10), characterized in that the at least one lifting unit (110A, 110B) comprises at least one position compensation device (118) configured to be activated in the loading / unloading position and / or in the at least one intervention position to compensate for local vertical displacements between the offshore floating intervention platform (10) and the floating offshore wind turbine platform (14) when the offshore floating intervention platform (10) is docked to the floating offshore wind turbine platform (14).

2. 2. The offshore floating intervention platform (10) of claim 1, wherein the position compensation device (118) comprises at least one controller (152) of the lifting actuators (116) configured to control the lifting actuators (116) to generate a vertical compensating movement of the equipment elevator (114) in response to a local vertical displacement between the offshore floating intervention platform (10) and the floating offshore wind turbine platform (14).

3. 3. The offshore floating intervention platform (10) of claim 2, wherein the position compensation device (118) comprises at least one sensor (150) configured to provide data representative of a local vertical displacement between the offshore floating intervention platform (10) and the floating offshore wind turbine platform (14), and the controller (152) is configured to receive data representative of the local vertical displacement from the sensor (150).

4. 4. The offshore floating intervention platform (10) according to any one of claims 1 to 3, wherein the equipment elevator (114) comprises a boom arm (130) projecting from the mast (112) and a grab cradle (132) carried by the boom arm (130), the grab cradle (132) defining at least one wind turbine equipment housing (138) defining a wind turbine equipment containment axis (F-F').

5. 5. The offshore floating intervention platform (10) of claim 4, wherein the boom arm (130) is telescopic and the grab cradle (132) is movable away from the mast (112) by telescopic deployment of the boom arm (130).

6. The offshore floating intervention platform (10) of claim 4 or 5, wherein the grab cradle (132) is configured to translate along the boom arm (130).

7. 7. The offshore floating intervention platform (10) according to any one of claims 4 to 6, wherein the grab cradle (132) comprises a lateral displacer (140) configured to move wind turbine equipment retained in the housing (138) along the containment axis (F-F').

8. 8. The offshore floating intervention platform (10) according to any one of claims 4 to 7, wherein the grab cradle (132) has a rotary displacer configured to rotate wind turbine equipment retained in the housing (138) about the equipment containment axis (F-F').

9. 9. The offshore floating intervention platform (10) according to any one of claims 4 to 8, wherein the lifting unit (110A, 110B) comprises an additional position compensation device mounted between the boom arm (130) and the grab cradle (132), the additional position compensation device being configured to be activated in the unloading / loading position and / or the at least one intervention position in order to compensate for local displacements between the offshore floating intervention platform (10) and the floating offshore wind turbine platform (14) when the offshore floating intervention platform (10) is docked to the floating offshore wind turbine platform (14).

10. 10. The offshore floating intervention platform (10) according to any one of claims 1 to 9, wherein the equipment lifting tower (100) comprises at least two lifting units (110A, 110B), each lifting unit comprising a mast (112), an equipment elevator (114) configured for vertical movement along the mast (112), and a lifting actuator (116) configured for actuating the movement of the equipment elevator (114), wherein the lifting actuators (116) of the two lifting units (110A, 110B) are independently operable.

11. 11. The offshore floating intervention platform (10) according to claim 10, wherein the masts (112) of the lifting units (110A, 110B) have parallel axes or at least one mast (112) of one lifting unit (110B) has an axis that is inclined with respect to the axis of the mast (112) of another lifting unit (110A).

12. The offshore floating intervention platform (10) according to any one of the preceding claims, wherein the lifting actuator (116) comprises a rack and pinion mechanism, a hydraulic mechanism, a pneumatic mechanism, or a winch mechanism.

13. 13. The offshore floating intervention platform (10) according to any one of claims 1 to 12, wherein the at least one lifting unit (110A, 110B) is configured to surround the wind turbine equipment and comprises at least one washing unit (160a) configured to move along the wind turbine equipment and / or the at least one lifting unit (110A, 110B) is configured to surround the wind turbine equipment and comprises at least one reinforcement unit (160b) configured to move along the wind turbine equipment and to mechanically reinforce the wind turbine equipment.

14. 14. An assembly comprising: a floating offshore wind turbine platform (14); and an offshore floating intervention platform (10) according to any one of claims 1 to 13 removably docked to the floating offshore wind turbine platform (14).

15. - docking an offshore floating intervention platform (10) according to any one of claims 1 to 13 to an offshore floating wind turbine platform (14); - placing said wind turbine equipment elevator (114) in one of said lower unloading / loading position or said at least one upper intervention position; - activating the position compensation device (118) at the loading / unloading position or at the at least one intervention position to compensate for local vertical displacements between the offshore floating intervention platform (10) and the floating offshore wind turbine platform (14); - performing an installation and / or maintenance intervention on a wind turbine (20) of said floating offshore wind turbine platform (14).

16. 16. The method of intervention according to claim 15, comprising the step of moving the elevator (114) between the lower unloading / loading position and the at least one intervention position, and the position compensation device (118) is stopped during the displacement of the elevator (114) between the lower unloading / loading position and the at least one intervention position.

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