Wind turbine multi-panel blade

1. A wind turbine blade comprising at least one central spar longitudinal section ( 7 ) and at least two shell longitudinal sections ( 5 , 9 ), wherein:

a) each central spar section ( 7 , 7 ′, 7 ″) is composed of only two cap prefabricated panels ( 15 , 17 ) and two single-piece web prefabricated panels ( 19 , 21 ) placed side by side in a box shape;

b) each shell section ( 5 , 5 ′, 5 ″, 5 ′″, 5 ″″; 9 , 9 ′, 9 ″, 9 ′″) forming, respectively, a leading edge and a trailing edge of the corresponding blade section is placed adjacently to a central spar section ( 7 , 7 ′, 7 ″);

c) each shell section ( 5 , 5 ′, 5 ″, 5 ′″, 5 ″″; 9 , 9 ′, 9 ″, 9 ′″) is composed of at least a single prefabricated panel ( 31 , 33 );

d) an aerodynamic surface of the blade is composed of just said cap panels ( 15 , 17 ) and shell prefabricated panels ( 31 ; 33 ); and

e) joints between panels are carried out by chemical and/or mechanical joints.

2. A wind turbine blade according to claim 1 , wherein the shell sections ( 9 , 9 ′, 9 ″, 9 ′″) forming the trailing edge are composed of a first prefabricated panel ( 23 ) in a pressure side and a second prefabricated panel ( 25 ) in a suction side.

3. A wind turbine blade according to claim 1 , wherein the shell sections ( 5 , 5 ′, 5 ″, 5 ′″, 5 ″″) forming the leading edge are composed of a first prefabricated panel ( 11 ) in a pressure side and a second prefabricated panel ( 13 ) in a suction side.

4. A wind turbine blade according to claim 1 , wherein the trailing edge shell sections ( 9 , 9 ′, 9 ″, 9 ′″) also include an additional tip part ( 35 ).)

5. A wind turbine blade according to claim 1 , wherein the blade also comprises a longitudinal tip section ( 10 ).

6. A wind turbine blade according to claim 1 , wherein the number of said shell longitudinal sections ( 5 , 5 ′, 5 ″, 5 ′″, 5 ″″; 9 , 9 ′, 9 ″, 9 ′″) is equal or greater than the number of said central spar longitudinal sections ( 7 , 7 ′, 7 ″).

7. A wind turbine blade according to claim 6 , wherein the blade comprises one central spar longitudinal section ( 7 ) and two shell longitudinal sections ( 5 , 9 ).

8. A wind turbine blade according to claim 6 , wherein the blade comprises one central spar longitudinal section ( 7 ) and several shell longitudinal sections ( 5 ′, 5 ″, 5 ′″, 5 ″″; 9 ′, 9 ″, 9 ′″).

9. A wind turbine blade according to claim 6 , wherein the blade comprises several central spar longitudinal sections ( 7 ′, 7 ″) and several shell longitudinal sections ( 5 ′, 5 ″, 5 ′″; 9 ′, 9 ″, 9 ′″).

10. A wind turbine blade according to claim 9 , wherein the cap panels ( 15 , 17 ) of at least two central spar longitudinal sections ( 7 ′, 7 ″) have a different material and/or structural configuration.

11. A wind turbine blade according to claim 1 , wherein the cap panels ( 15 , 17 ), the web panels ( 19 , 21 ), and the shell panels ( 11 , 13 ; 25 , 27 ; 31 , 33 ) have joint areas having planar extensions ( 41 , 43 , 45 ) in edges of the joint areas, and said planar extensions ( 41 , 43 , 45 ) are parallel and overlapping.

12. A wind turbine blade according to claim 1 , wherein all joints between panels are carried out by mechanical joints.

13. A wind turbine blade according to claim 1 , wherein joints between the central spar panels ( 15 , 17 , 19 , 21 ) are carried out by chemical joints and joints between shell panels ( 11 , 13 ; 23 , 25 ; 31 ; 33 ) and central spar panels ( 15 , 17 , 19 , 21 ) are carried out by mechanical joints.

14. A wind turbine blade according to claim 1 , wherein all joints between panels are carried out by a combination of chemical-mechanical joints.

15. A wind turbine blade according to claim 1 , wherein the material of the cap panels ( 15 , 17 ) includes one of the following:

a Carbon Fiber Reinforced Plastic;

a Glass Fiber Reinforced Plastic.

16. A wind turbine blade according to claim 1 , wherein the structural configuration of the cap panels ( 15 , 17 ) includes one of the following:

a solid laminate;

a sandwich configuration.