| WO/2002/099278 | METHOD AND MEANS FOR MOUNTING A WIND TURBINE ON A TOWER |
| WO/2015/101762 | OFFSHORE WIND TURBINE |
| WO/2014/108216 | SAFETY DEVICE FOR AN OPERATOR DURING THE SERVICING OF A HUB OF A WIND TURBINE |
KNUDSEN JAN INGAR (NO)
| WO2008132226A1 | 2008-11-06 |
| US20060120809A1 | 2006-06-08 | |||
| DE10332382A1 | 2005-02-17 |
| C l a i m s 1. A device for installing or dismounting turbine blades on an offshore wind turbine, said device being adapted to be installed on the deck of an installation vessel, said vessel incorporating a crane (17) for operating the device, 5 c h a r a c t e r i z e d i n • an installation frame (1) with a first end and a second end, and with a number of locking clamps (3) for holding a turbine blade (7) to be installed, • a support structure (2) with a first end and a second end, the support structure (2) including a hinge system (5) near its first end, the hinge system (5) being adapted to I0 releasably hold one end of the installation frame (1), • a steering mechanism adapted to control the position of one end of the installation frame (1) in relation to the first end of the support structure (2). 2. A device as claimed in claim 1, wherein the steering mechanism includes: • a first boom (8) with a first snatch block (9), a first tugger winch (10) and a first is steering wire (1 1), • a second boom (9) with a first snatch block, a second tugger winch (12) and a second steering wire (13), • a third tugger winch ( 15) and a third steering wire ( 16). 3. A device as claimed in claim 1, wherein the steering mechanism includes a number 0 of hydraulic cylinders and telescopic arms attached to the vessel. 4. A device as claimed in claim 1, wherein the support structure (2) further includes a turntable (4) onto which the hinge system (5) is mounted, and a sliding track system (6). 5. A method for installing a turbine blade on an offshore wind turbine, wherein the blade is loaded onto an installation vessel and brought out to an installation site, the 5 installation vessel being positioned near a tower of the wind turbine, c h a r a c t e r i z e d i n • clamping the blade to an installation frame mounted on the deck of an installation vessel, the installation frame being releasably hinged in a first end to the deck near one side of the vessel and next to said tower, • raising the frame into a vertical position, • attaching a steering mechanism to the first end of said installation frame, • releasing the installation frame from the vessel, • raising the installation frame with the blade into close proximity of a hub on the wind turbine, • fastening the blade to the hub, • releasing the blade from the installation frame, • removing the installation frame from the wind turbine. |
Field of the Invention
The present invention relates to a device for installing turbine blades on offshore wind turbines.
Background
Due to the noise and intermittent shadows generated by wind turbines, it has been proposed to install the turbines in offshore wind farms, either as floating structures anchored in deep water areas, or as bottom-mounted structures in shallow water areas just off the coast.
In the case of bottom-mounted wind turbines, one installation procedure includes first to design a support structure rammed into the bottom and then to mount a wind turbine tower upon this support. On this tower there is mounted a turbine housing, and lastly there is installed a number of turbine blades onto a hub protruding from the housing. All work is carried out with vessel-mounted cranes.
In the case of the turbine blades, the process of hoisting and mounting of the blades to the hub is a substantial task, as the turbine blades vary in size from approximately 50 m in length to more than 60 m for the largest turbines and the weight varies from approximately 18 tonnes to more than 22 tonnes. With the method used today, where the blades are more or less free hanging from the crane hook, the installation operation has to come to a halt when the wind speed reaches approximately 8 m/s. This prohibits installation operations through the winter in North European waters. Apart from this, the installation is a risky process for the workers fastening the large swinging masses of the blades to the turbine shaft with bolts and nuts. A turbine blade is also easily damaged if it should hit another structure, such as the support shaft or the crane boom. Even small dents in the blade are not allowed as they later may cause cracks forming in the blade.
Summary of the Invention
One object of the present invention is to provide a device and method for handling wind turbine blades making it possible to install turbine blades offshore in a more efficient and safe manner in near to unrestricted wind conditions. The present invention, as defined in the appended claims, tries to meet this object.
By use of the proposed handling system, blades can be installed through the winter time. In addition, for a typical offshore wind farm location, the installation operability will increase from approximately 60% to approximately 98% in the summer months.
The system ensures that the blades throughout the installation operation are protected and under full control.
Brief Description of the Drawings
The present invention and its advantages will be better understood by reference to the following detailed description and the attached drawings, in which:
Fig. la-f is a drawing of one component of the inventive device, the installation frame, in side, front, back, perspective and end views,
Fig. 2a-c is a drawing of another component, the support structure, in top, side and perspective views,
Fig. 3 is a view of the general arrangement of the inventive device,
Fig. 4 - 8 is a sequence showing the installation of a turbine blade with the inventive device,
Fig. 9 is an illustration showing the steering wire arrangement of the invention,
Fig. 10 - 12 is a continuation of the sequence shown in Fig. 4 - 8; the removal of the inventive device,
Fig. 13 - 18 is a sequence correspondent to Fig. 4 - 7, showing the initial steps when installing a turbine blade that is delivered the other way around.
Detailed Description
The turbine blades are normally delivered to the installation vessel in port and stored horizontally in a rack on deck. The vessel includes a device according to the invention mounted on deck beside the rack, i.e. spanning the width of the vessel transverse to its keel direction. When the installation vessel has arrived at the installation site, the inventive device is used for raising the blades from the deck into a vertical position in close proximity of the turbine shaft hub ready for mounting.
A device according to the invention includes two frame-like structures, Fig. 1 and 2, one nested into the other. The general assembly is shown in Fig. 3 mounted on the deck of an installation vessel beside the rack holding the turbine blades. This is an embodiment of the invention wherein the operation of the frame-like structures is controlled by wires and winches.
The device includes a structure that has a u-shaped cross section, called the installation frame 1, see Fig. 1. The installation frame 1 is equipped with clamps 3 that can rotate and lock a blade 7 in the frame 1.
Further, there is a support structure 2 which includes a sliding track system 6 and a turntable 4 with a hinge system 5. The hinge system and turntable are installed at a first end of the support structure. The support structure 2 is shown in Fig. 2. In addition there are tugger winches, or hydraulic support arms (not shown on the figures), that control the position of the bottom of the installation frame when it is brought into a vertical position.
The general arrangement is shown in Fig. 3 with the installation frame 1 resting on the support structure 2. The clamps 3 of the installation frame 1 are open and ready for receiving a turbine blade. The installation frame 1 is in a first end locked to the releasable hinge system 5 of the support structure 2.
Further, one can see the tugger winches 10, 12 and their steering wires 11, 13 that are attached to the bottom of the installation frame 2. There are two booms 8, 8', one on each side of the turbine tower 14, which carry a snatch block 9, 9' for the steering wires 11, 13 in order to give them suitable angle to control the position of the bottom of the installation frame 1 when this is released from the hinge system 5 on the turntable 4.
A third line 16 directly from the deck of the vessel ensures full control in all directions. For this purpose, a third tugger winch 15 is mounted on the deck, see Fig. 9.
Instead of the tugger wire arrangement, the control of the bottom of the installation frame may be performed by a system consisting of hydraulic cylinders and telescopic arms attached to the vessel. Behind the installation frame racks with blades ready for installation are shown.
The turbine blade 7 is positioned into the installation frame 1 with the leading edge downwards. Clamps 3 grip the blade 7 and hold it into position. These clamps 3 have an outer layer of a soft material that does not harm the blade, and are operated either by s hydraulics or by pneumatics.
Fig. 4 shows the blade being lifted towards the installation frame suspended in a crane 17, and Fig. 5 shows the blade secured in the installation frame. The crane wire is attached to the installation frame which is ready to be up-ended.
When the blade 7 is securely locked in the installation frame 1 , the crane wire is used too up-end the frame 1 while it rotates around a hinge system 5 on the turntable 4 of the support structure 2. Fig. 6 shows the frame 1 during up-ending.
The installation frame 1 is then brought to a vertical position where the bottom of the frame is still secured in the hinge system 5 on the turntable 4, see Fig. 7.
At this stage the steering wires 11, 13 16 are attached to the installation frame 1 before thes frame 1 is released from the hinge system 5 on the turntable 4. Fig. 8 shows the installation frame 1 being lifted from the deck into position for installation of the blade 7, and Fig. 9 shows the arrangement with tugger winches 10, 12, 15 and steering wires 11, 13, 16.
When the blade 7 has been secured to the hub with sufficient number of bolts and nuts, the clamps 3 of the installation frame 1 are opened either remotely controlled or through control0 cable between the frame 2 and the deck of the vessel, see Fig. 10. The frame 1 is then pulled down into the hinge system 5 on the turntable 4 by the steering winches 10, 12, 15, see Fig. 11.
The crane 17 will then lay the frame 2 down back in horizontal position and ready for the next blade, see Fig. 12. 5 The blades are often positioned in racks such that every second blade has the tip in the opposite direction. In this case the idea of the system is that the blades can be safely positioned in the installation frame without having to turn the blades 180 degrees, and still be brought to a vertical position with the right direction for installation. The tip of the blade is always positioned inside the installation frame, while the hub end always protrudes outside the frame. In case the tip is closest to the turbine, the installation frame is lifted in the far end and pivoted around the hinge on the turntable.
When brought into vertical position, the tugger lines, or the hydraulic guidance arms are attached to the bottom of the installation frame. This case has been described above.
The following describes the case where the tip is in the far end away from the wind turbine. The blade is lifted into the installation frame, see Fig. 13.
When the blade is locked in the frame, the crane wire is attached to the frame in the end closest to the wind turbine, see Fig. 14.
The installation frame is then lifted in the near end while the far end is guided along the deck in a track system in the support structure, see Fig. 15. When the far end of the frame reaches the hinge system at the turntable and the installation frame is brought to vertical, the far end is locked into the hinge system, see fig 16.
After up-ending, the blade will be on the wrong side of the installation frame as shown on Fig. 16. The turntable will therefore rotate the installation frame 180 degrees around the vertical axis such that the frame and blade are in the correct position for installation of the blade.
Fig. 17 shows the frame being rotated and Fig. 18 shows the frame rotated 180 degrees.
From this point the operation is identical to what has been described above, see figs. 8 - 12.
The third blade is then installed either with the method applied for the first or for the second blade.
The clamps in the installation frame can be adjusted or replaced to suit the particular blade design, and their longitudinal position may also be adjusted.
While the inventive device and method described above relate to the installation of wind turbine blades, the invention may also be used for the opposite procedure, namely the dismounting of an offshore wind energy installation.