Design for flangeless wind tower

• US 20100071275A1
• Filed: 09/25/2008
• Published: 03/25/2010
• Est. Priority Date: 09/25/2008
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Sathian, Sujith, Cairo, Ronald R., Mathai, Manu
• Granted Patent: US 8,056,297 B2
• Time in Patent Office: Days
• US Class Current: 52/40
• CPC Class Codes: E04H 12/08 of metal
• CPC Class Codes: F05B 2240/912 on a tower
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/728 Onshore wind turbines
• CPC Class Codes: Y10T 403/55 Member ends joined by inserted section

Abstract

A method for stiffening a wind turbine tower employing fingerplate assemblies on flangeless joints between adjacent tubular tower sections. The method includes limiting the intercan gap between adjacent end surfaces of the tower sections at the flangeless joints and selecting a number of fingerplates to fasten each flangeless joints to limit distortion. Establishing dimensions for the fingerplates may further minimize localized tower distortion. Selecting a material for the fingerplate with a lower Young'"'"'s modulus than a material for the tubular section also results in reduced localized tower distortion. Attaching a coverplate to a top tubular section limits tip displacement for the tower.

Claims

1. A wind turbine tower comprising:

a plurality of tubular sections, wherein each tubular section of the plurality of tubular sections includes substantially planar end surfaces;

a plurality of flangeless joints, wherein each individual flangeless joint is arranged between opposing end surfaces of adjacent tubular sections;

a plurality of fingerplate assemblies uniformly distributed around a periphery of each flangeless joint, wherein each fingerplate includes a circumferential angle, a longitudinal dimension, and a radial thickness.

means for stiffening the wind turbine tower against lateral sway.

2. The wind turbine tower according to claim 1, wherein the plurality of tubular sections includes a plurality of conical tubular sections.

3. The wind turbine tower according to claim 1, wherein the substantially planar end surfaces comprise a controlled intercan gap between adjacent tubular sections.

4. The wind turbine tower according to claim 3, wherein the means for stiffening the wind turbine tower against lateral sway comprise:

a controlled intercan gap preferentially maintained at approximately 0 mm.

5. The wind turbine tower according to claim 3, wherein means for stiffening the wind turbine tower against lateral sway comprises:

three fingerplate assemblies uniformly distributed around the periphery of each flangeless joint at a circumferential angle of about 40 degrees to 55 degrees.

6. The wind turbine tower according to claim 5, wherein each of the three fingerplate assemblies uniformly distributed around the periphery of each flangeless joint comprises:

a designated longitudinal dimension of approximately 1000 mm to 1100 mm.

7. The wind turbine tower according to claim 6, wherein a radial thickness of the fingerplate assemblies comprises approximately 40 mm.

8. The wind turbine tower according to claim 7, wherein each of the three fingerplate assemblies uniformly distributed around the periphery of each flangeless joint comprises:

four bolt rows including approximately eight bolts to ten bolts per bolt row.

9. The wind turbine tower according to claim 7, wherein each of the three fingerplate assemblies uniformly distributed around the periphery of each flangeless joint comprises:

a material having a Young'"'"'s modulus lower than a Young'"'"'s modulus for a material of the tubular sections.

10. The wind turbine tower according to claim 5, wherein the top section of the wind tower comprises:

a stiffening coverplate engaged at a top end.

11. The wind turbine tower according to claim 10, wherein the stiffening coverplate comprises:

backing stiffeners.

12. The wind turbine tower according to claim 10, wherein the stiffening coverplate further comprises a material with a high Young'"'"'s modulus relative to the Young'"'"'s modulus for the fingerplate assemblies.

13. A method adapted for stiffening a wind turbine tower employing fingerplate assemblies on plurality of flangeless joints between a plurality adjacent tubular sections with substantially planar end surfaces, comprising:

limiting the intercan gap between adjacent end surfaces of the plurality tower sections at the flangeless joints joined by fingerplate assemblies;

selecting a number of fingerplates to fasten each joint of the plurality of flangeless joints;

establishing a circumferential angle, a longitudinal length and a radial thickness for a fingerplate of the fingerplate assembly;

selecting a material with a Young'"'"'s modulus for the fingerplate to be lower than a Young'"'"'s modulus for a material of the tubular section; and

attaching a coverplate adapted for stiffening the wind tower to an upper end of a top tubular section.

14. The method according to claim 13, the step of limiting intercan gap comprising:

limiting the intercan gap to approximately about 0 mm.

15. The method according to claim 13, the step of selecting a number of fingerplates to fasten each joint comprising:

determining a minimum number of fingerplates per joint providing acceptable, localized, tower distortion with limited intercan gaps.

16. The method according to claim 15, the step of determining a number of fingerplates comprising:

selecting three fingerplates to fasten each joint.

17. The method according to step 16, the step of establishing a circumferential angle, a longitudinal length and a radial thickness for a fingerplate of the fingerplate assembly comprising:

minimizing tower distortion while maintaining a constant material volume for a determined number of fingerplates.

18. The method according to step 17, further comprising:

setting a circumferential angle of about 40 to about 55 degrees;

setting a longitudinal length of about 1000 mm to about 1100 mm; and

setting a thickness of about 40 mm.

19. The method according to step 13, the step of stiffening a top end comprising:

providing stiffening members on a surface of the rigid coverplate.

20. The method according to step 19, the step of stiffening a top end comprising:

choosing a material for the rigid coverplate with a high Young'"'"'s modulus relative to the Young'"'"'s modulus for a material of the fingerplates.

21. A wind turbine tower comprising:

a plurality of tubular sections, wherein each tubular section of the plurality of tubular sections includes substantially planar end surfaces forming a controlled intercan gap between adjacent tubular sections;

a plurality of flangeless joints, wherein each individual flangeless joint is arranged between opposing end surfaces of adjacent tubular sections, including three fingerplate assemblies uniformly distributed around a periphery of each flangeless joint;

the fingerplate assemblies including a circumferential angle, a longitudinal length and a radial thickness optimized for tower stiffness; and

comprising a material with a Young'"'"'s modulus for the fingerplate to be lower than a Young'"'"'s modulus for a material of the tubular section; and

a coverplate attached to a top tubular section of the wind turbine tower, wherein the coverplate includes a material with a high Young'"'"'s modulus relative to the Young'"'"'s modulus for a material of the fingerplates.