Method and device for blade replacement in wind turbines
Method and device for replacing a blade ( 13 ) in wind turbines that comprises two elements, one upper ( 1 ) and the other lower ( 2 ) that work together to raise and/or lower the blade ( 13 ) of a wind turbine. The device's upper element or “top” ( 1 ) comprises some elements ( 4 ) bolted to the bearing ( 3 ) of the wind turbine and some means of fastening ( 5 ) the blade ( 13 ), while the lower element or “ground” ( 2 ) is a structure that encompasses the wind turbine tower ( 8 ) and has at least two winches ( 2.5 ) and two deviation pulleys ( 2.4 ) to connect some cables ( 6 ) between the device elements, namely the “top” ( 1 ) and “ground” ( 2 ).
1. A wind turbine blade replacement device for use in maintenance or installation tasks at wind farms, the device comprising two elements ( 1 , 2 ) that work together to ensure the correct elevation/descent of a wind turbine blade ( 13 ), namely a “top” element ( 1 ) positioned between a hub ( 15 ) and the wind turbine blade ( 13 ), and a “ground” element ( 2 ) positioned at a base of a wind turbine tower ( 8 ),
wherein the “ground” element ( 2 ) consists of a structure ( 2 . 1 ) formed by sections comprising some fixed rollers ( 2 . 2 ), a centering roller ( 2 . 3 ), some deviation pulleys ( 2 . 4 ), some winches ( 2 . 5 ), a dismountable structure ( 2 . 1 ), a counterweight ( 2 . 6 ), an electrical panel ( 2 . 7 ) and control elements: an inclinometer and some load cells mounted on the deviation pulleys ( 2 . 4 ) of the counterweight ( 2 . 6 ) for controlling a tension in a cable ( 6 ).
2. The wind turbine blade replacement device according to claim 1 , wherein a main section of the structure ( 2 . 1 ) supports the winches ( 2 . 5 ), the electrical panel ( 2 . 7 ) and the fixed rollers ( 2 . 2 ), and is positioned at the base of the tower ( 8 ).
3. The wind turbine blade replacement device according to claim 1 , wherein parallel sections of the structure ( 2 . 1 ) are symmetrical and bolted to the main section perpendicularly.
4. The wind turbine blade replacement device according to claim 1 , wherein counterweights ( 2 . 6 ) are placed on ends of the parallel sections and a front section equipped with an adjustable centering roller ( 2 . 3 ) is placed between the parallel sections.
5. The wind turbine blade replacement device according to claim 1 , wherein the electrical panel ( 2 . 7 ) has a startup push-button and an emergency push-button, a touchscreen to view the status of the various elements constituting the blade ( 13 ) replacement device in addition to indicators for the tension and movement of the cable ( 6 ) connected to the load cells of the pulleys ( 2 . 4 ) for the counterweights ( 2 . 6 ), a selector and some alarm pilot lights for operation of the winches ( 2 . 5 ).
6. The wind turbine blade replacement device according to claim 1 , the “top” element ( 1 ) comprising two parts ( 4 , 5 ), a first part ( 4 ) fastened on a blade bearing ( 3 ) of the hub ( 15 ) and a second part ( 5 ) in a form of a flange that encompasses a root ( 7 ) of the blade ( 13 ).
7. The wind turbine blade replacement device according to claim 6 , wherein the first part ( 4 ) of the “top” element ( 1 ) that is fastened on the blade bearing ( 3 ) has various horizontal deviation pulleys ( 4 . 2 ) and vertical deviation pulleys ( 4 . 1 ), and various fastening elements ( 4 . 3 ) for the cable ( 6 ), which are placed on an outer track of the bearing ( 3 ) of the blade on the hub ( 15 ) and whose function is to support, drive and fasten the cable ( 6 ) that rises from winches ( 2 . 5 ) at the “ground” element ( 2 ) and attached to the flange ( 5 ) for the blade ( 13 ) on the “top” element ( 1 ).
8. The wind turbine blade replacement device according to claim 6 , wherein the flange ( 5 ) for the blade ( 13 ) on the “top” element ( 1 ) comprises two segments of pulley ( 5 . 1 ) and at least two joint segments ( 5 . 2 ), bolted together with some fastening bolts ( 5 . 3 ) that, in cooperation with some shims ( 5 . 4 ), enable a diameter of the flange ( 5 ) to be adjusted to a diameter of the root ( 7 ) of the blade ( 13 ).
9. The wind turbine blade replacement device according to claim 8 , wherein the segments of the pulley ( 5 . 1 ) comprises a pulley ( 9 ) and a reinforcement element ( 10 ).
10. A wind turbine blade replacement device for using in maintenance or installation tasks at wind farms, the device comprising two elements ( 1 , 2 ) that work together to guarantee the correct elevation/descent of the wind turbine blade ( 13 ), namely a “top” element ( 1 ) positioned between a hub ( 15 ) and the wind turbine blades ( 13 ), and a “ground” element ( 2 ) positioned at a base of a wind turbine tower ( 8 ),
wherein the “ground” element ( 2 ) comprises a structure ( 2 . 1 ) formed by sections comprising some fixed rollers ( 2 . 2 ), a centering roller ( 2 . 3 ), some deviation pulleys ( 2 . 4 ), some winches ( 2 . 5 ), a dismountable structure ( 2 . 1 ), a counterweight ( 2 . 6 ), an electrical panel ( 2 . 7 ) and control elements: an inclinometer and some load cells mounted on the deviation pulleys ( 2 . 4 ) of the counterweights ( 2 . 6 ) for controlling the tension in a cable ( 6 ).
11. A method of replacing the wind turbine blade of the sort that uses a device according to claim 1 , wherein the descent of the blade ( 13 ) entails the following steps:
placing the “ground” element ( 2 ) of the replacement device for the blade ( 13 ) at a tower base ( 8 );
mounting a flange ( 5 ) of the “top” element ( 1 ) onto a root ( 7 ) of the blade ( 13 ) intended for replacement/repair;
positioning the blade ( 13 ) vertical, pointing up, or horizontal
turning a wind turbine rotor until the blade ( 13 ) is in a horizontal position downward;
hoisting the cables ( 6 ) from the “ground” element ( 2 ) with an auxiliary crane (not represented) located on a wind turbine nacelle ( 14 );
running the cables ( 6 ) through pulleys ( 9 ) at pulley segments ( 5 . 1 ) of the flange ( 5 ) of the “top” element ( 1 ) on a root ( 7 ) of the blade ( 13 ) and through a horizontal deviation pulleys ( 4 . 2 ) and vertical deviation pulleys ( 4 . 1 ), and then securing the cables ( 6 ) to fastening elements ( 4 . 3 ) of a first part ( 4 ) on the “top” element ( 1 ) fastened onto a blade bearing ( 3 );
detaching a fastening of the auxiliary crane located on the wind turbine nacelle ( 14 );
guiding a retention tool on the blade with a conventional retention system;
unbolting the blade ( 13 ) from the bearing ( 3 ) of a wind turbine hub ( 15 ); and
lowering the blade ( 13 ) by engaging the winches ( 2 . 5 ) at the “ground” element ( 2 ) of the replacement device for the blade ( 13 ), assisted by a conventional retention system, and then positioning the blade ( 13 ) horizontally on the ground.
12. The method of replacing a wind turbine blade according to claim 11 , wherein the hoisting of the blade ( 13 ) follows the steps for lowering the blade ( 13 ) in a reverse order.