REINFORCED WIND TURBINE BLADE

• US 20110171024A1
• Filed: 06/23/2009
• Published: 07/14/2011
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: Bladena Solutions ApS
• Original Assignee: Bladena Aps
• Inventors: Jensen, Find Mølholt
• Granted Patent: US 8,807,953 B2
• Time in Patent Office: Days
• US Class Current: 416/1
• CPC Class Codes: F03D 1/0675 of the blades
• CPC Class Codes: F03D 3/062 characterised by their construction elements
• CPC Class Codes: F05B 2210/16 Air or water being indistinctly used as working fluid, i.e. the machine can work equally with air or water without any modification
• CPC Class Codes: F05B 2240/301 Cross-section characteristics
• CPC Class Codes: F05B 2280/6003 Composites; e.g. fibre-reinforced
• CPC Class Codes: F05C 2253/04 Composite, e.g. fibre-reinforced
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/74 Wind turbines with rotation axis perpendicular to the wind direction

Abstract

The present invention relates to a reinforced blade for a wind turbine, particularly to a blade having at least one elongated reinforcing member connected inside the shell for increasing the strength of the blade, each of the at least one elongated reinforcing member having a first end and a second end and extending in a longitudinal direction between the first end and the second end and wherein the first end is connected to the upper part of the shell and the second end is connected to the lower part of the shell thereby decreasing peeling and shear stresses in the trailing edge of the blade.

Claims

1. A wind turbine blade, comprising:

a shell having a section with an aerodynamic profile, and

at least one elongated reinforcing member connected inside the shell for increasing the strength of the blade, each of the at least one elongated reinforcing member having a first end and a second end and extending in a longitudinal direction between the first end and the second end and wherein the first end is connected to the upper part of the shell and the second end is connected to the lower part of the shell thereby preventing deformation of the trailing part of the shell.

2. A wind turbine blade according to claim 1, wherein the at least one elongated reinforcing member comprises a plurality of elongated reinforcing members positioned in spaced relationship along the longitudinal extension of the blade.

3. A wind turbine blade according to claim 1, wherein at least one of the at least one elongated reinforcing member extends in a direction that forms an angle with relation to a longitudinal extension of the blade ranging from 70°

to 110°

, preferably from 80°

to 100°

, more preferred from 85°

to 95°

.

4. A wind turbine blade according to claim 3, wherein at least one of the at least one elongated reinforcing member extends in a direction that is substantially perpendicular to the longitudinal extension of the blade.

5. A wind turbine blade according to claim 1, wherein at least one of the at least one elongated reinforcing member extends substantially perpendicular to the profile chord of the blade.

6. A wind turbine blade according to claim 1, wherein the at least one elongated reinforcing member comprises a plurality of elongated reinforcing members positioned in spaced relationship along the longitudinal extension of the blade with a mutual distance that is less than 2×

D, wherein D is the distance between the first and second end of one of the plurality of elongated reinforcing members.

7. A wind turbine blade according to claim 1, wherein one of the at least one elongated reinforcing member forms an angle with another one of the at least one elongated reinforcing member.

8. A wind turbine blade according to claim 7, wherein the angle ranges from 15°

to 135°

.

9. A wind turbine blade according to claim 1, further comprising at least one girder, and wherein each of the at least one elongated reinforcing member is positioned between the at least one girder and the trailing edge of the blade.

10. A wind turbine blade according to claim 9, wherein at least one of the at least one elongated reinforcing member extends substantially in parallel to the girder.

11. A wind turbine blade according to claim 9, wherein at least one of the at least one elongated reinforcing member forms an angle with the girder ranging from 0°

to 70°

, preferably from 0°

to 40°

, more preferred from 0°

to 20°

, even more preferred form 0°

to 10°

, and most preferred from 0°

to 5°

.

12. A wind turbine blade according to claim 9, wherein at least one of the at least one elongated reinforcing member forms an angle with the girder ranging from 10°

to 70°

, preferably from 10°

to 40°

, more preferred from 10°

to 20°

.

13. A wind turbine blade according to claim 1, wherein at least one of the at least one elongated reinforcing member is a flexible wire with high tensional strength without a capability of resisting compression forces.

14. A wind turbine blade according to claim 1, wherein at least one of the at least one elongated reinforcing member is made of reinforced plastic.

15. A wind turbine blade according to claim 1, wherein at least one of the at least one elongated reinforcing member is made of wood, such as bamboo, birch, plywood, etc, or, steel, light metal alloys, etc.

16. A wind turbine blade according to claim 1, wherein at least one of the at least one elongated reinforcing member comprises a number of individual elements comprising glass fibres, carbon fibres, aramid fibres, polyethylene fibres, or PBO fibres (polypheylene benzobisoxqazole).

17. A wind turbine blade according to claim 1, wherein at least one of the at least one elongated reinforcing member is made of material based on plant fibres with high cellulose content, such as bast fibres, such as flax, jute, etc.

18. A method of increasing the strength of a wind turbine blade having a shell with a section having an aerodynamic profile, the method comprising:

positioning at least one elongated reinforcing member inside the shell, each of the at least one elongated reinforcing member having a first end and a second end and extending in a longitudinal direction between the first end and the second end; and

connecting the first end to the upper part of the shell and the second end to the lower part of the shell.