System and method for reinforcing a weakened area of a wind turbine blade

1. System for reinforcing a weakened area of a wind turbine blade when said blade is mounted on a wind turbine, wherein an interior of the blade comprises a box beam extending from a blade root to a blade tip, wherein the box beam has an open end at the blade root, the system comprising:

a module comprising a plurality of units including a first unit and a second unit, wherein the first unit comprises means for moving the module along the interior of the box beam, and

wherein the second unit comprises:

(a) means for carrying a reinforcing element and for expanding upon activation to press the reinforcement element against the interior of the box beam to repair the weakened area when the first unit moves the module to a position with the second unit adjacent to the weakened area; or

(b) means for sanding the weakened area when the first unit moves the module to a position with the second unit adjacent to the weakened area; or

(c) means for suctioning dirt or dust from the weakened area when the first unit moves the module to a position with the second unit adjacent to the weakened area; or

(d) means for applying a cleaning material to the weakened area when the first unit moves the module to a position with the second unit adjacent to the weakened area.

2. System according to claim 1 , wherein the second unit is detachably coupled to the first unit and the system comprises a set of additional units, each of which can be coupled to the first unit when the second unit is detached from the first unit.

3. System according to claim 2 , wherein the second unit comprises the means for carrying and expanding, wherein the means for carrying and expanding comprises at least two fasteners for fastening the reinforcement element while the module moves to the weakened area of the blade, and at least two expandable arms that expand to press the at least two ribs onto the interior of the box beam when the second unit is adjacent the weakened area of the blade.

4. System according to claim 3 , wherein the means for carrying and expanding further comprises means for spacing the at least two fasteners from walls of the box beam to keep the at least two fasteners from touching the box beam walls while the module moves to the weakened area of the blade.

5. System according to claim 2 , wherein the first unit comprises: a body comprising:

a motor,

a notched wheel coupled to said body and activated by the motor, wherein said notched wheel is adapted to roll along a first box beam wall; and

an articulated arm protruding from said body, wherein said articulated arm is adapted to remain in contact with a second box beam wall that is diametrically opposed to the first box beam wall while the module moves inside the box beam.

6. System according to claim 2 , wherein the set of additional units comprises a unit comprising means for applying at least one chemical product or detergent on an inner surface of the box beam walls.

7. System according to claim 2 , wherein the second unit comprises the means for carrying and expanding and the set of additional units comprises the means for sanding.

8. System according to claim 7 , wherein the means for sanding comprises a grinder mounted on a mobile head and a first actuator to move said mobile head on a path contained on a plane perpendicular to an inner surface of the walls of the box beam.

9. System according to claim 8 , wherein the means for sanding comprises secondary actuator to bring said mobile head to an oscillating movement depending on a path contained on a plane parallel to the inner surface.

10. System according to claim 9 , wherein the means for sanding comprises sensors arranged on the mobile head to delimit the path of said oscillating movement when detecting a box beam wall.

11. System according to claim 2 , wherein the second unit comprises the means for carrying and expanding and the set of additional units comprises the means for suctioning dirt or dust from the weakened area when the first unit moves the module to the weakened area, wherein the means for suctioning comprises an intake mouth, means to adapt a size of said intake mouth to a transversal section of the box beam; and at least two wheels as a spacer element mounted on both sides of the intake mouth to ensure a separation between the inner surface of the box beam and the intake mouth.

12. The system according to claim 1 , wherein the module comprises a video camera and a lighting system.

13. System according to claim 1 , wherein said system comprises a control unit interconnected with the module and, a support adapted to secure said control unit inside the blade root.

14. The system according to claim 1 , wherein the system comprises a positioning element that anchors to the box beam near the blade root and a guide bar placed on the box beam between the module and said positioning element; wherein said guide bar comprises one or more sections connected together and coupled as the module moves along the box beam; and wherein the positioning element prevents the transversal movement of the guide bar inside the box beam.

15. Method for reinforcing a weakened area of a wind turbine blade, comprising:

(a) providing the system of claim 1 ;

(b) transporting a reinforcement element inside the box beam from the blade root to said weakened area, and

(c) applying the reinforcement element on an interior of the box beam in said weakened area.

16. The system according to claim 1 , wherein the first unit comprises means for spacing the first unit from the walls of the box beam to prevent a body of the first unit from contacting the box beam walls while the first unit moves inside the box beam.