Low cost rail-transportable wind turbine tower

Abstract

A wind turbine tower is provided that will accommodate rail transport of wind turbine sections. The wind turbine tower includes a plurality of axial tubular sections, wherein the sections including an outer diameter no greater than a designated maximum diameter; a main structural element for each of the axial tubular sections, with the structural element being of a generally cylindrical shape; and corner reinforcements for the main structural elements. The corner reinforcements are provided generally equidistant around the circumference of the main structural element about 90 degrees apart. Corner supports may further be provided to support the corner reinforcements from a foundation of the wind turbine tower. With the corner reinforcements attached to the main structural elements, the combination falls within a space envelope that may be accommodated for rail transport.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates generally to wind turbine tower construction and more specifically to a wind tower and its method of construction that permits low cost rail transport of sections for large towers. Additionally, it permits upgrade of existing towers to be able to handle larger turbines.[0002]For many years it has been common practice to build steel wind tower sections separately in a workshop facility and then to move each complete section to the site, where the wind turbine tower installation was performed. The tower sections would typically have a cylindrical or slightly tapered shape, and each of the sections could in turn be divided along axial lines into an adequate number of shells.[0003]Due to the ever-increasing demand for larger capacity towers and consequently larger dimensions of all parts needed to build such towers, a physical limit has been imposed by the infrastructure, e.g. the clearance beneath a bridge or in a tunnel, is reache...

AI Technical Summary

Benefits of technology

"The present invention relates to an apparatus and method for transporting wind turbine towers to a windfarm site by rail. The invention allows for the sections of the towers to fit within a space envelope for rail transport. The invention also allows for the upgrade of existing towers to handle larger turbines. The wind turbine tower includes axial tubular sections with a main structural element and corner reinforcements. The support system includes corner reinforcements for the main structural elements of the axial tubular sections. The method includes supplying the axial tubular sections, shaping the main structural elements, forming the corner reinforcements, and attaching the corner reinforcements to the main structural elements. The corner reinforcements can be either on the outside or inside of the main structural elements. The technical effects of the invention include reducing transportation costs, simplifying logistical operations, and improving safety during transportation."

Problems solved by technology

Due to the ever-increasing demand for larger capacity towers and consequently larger dimensions of all parts needed to build such towers, a physical limit has been imposed by the infrastructure, e.g. the clearance beneath a bridge or in a tunnel, is reached.

Increased thickness would mean higher material costs and a requirement for heavier transportation vehicles, whether trucks, trains, ships, or helicopters, while diameters need to be small enough to limit vehicle heights in order to pass under bridges and though tunnels.

Also, thicker steel stock is harder to form and fabricate.

However, it is desirable to limit assembly in the field due to hostile terrain and severe environmental conditions.

Further, the creation of additional joints potentially subjects the tower to additional modes of failure.

Consequently with the lower cost of rail transport, the cost for transporting the top section is about 50% of the cost for transporting the base and mid-tower sections.

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