Effects on support structure design due to wake-generated turbulence

Effects on support structure design due to wake-generated turbulence

Guzman Tejada, Russell A.

Zaaijer, M.B. (mentor)

Aerospace Engineering

Sustainable Energy Technology

2014-10-24

As the world demands cleaner, sustainable and economical energy sources, the wind energy academia and industry battles to increase performance and reduce costs. One of the promising fields of study is wind turbine wakes in wind farms. The position of the turbines within the layout affects the intensity of their wake effects, such as reduced wind speed or turbulence, therefore the choice of its position has an impact on wake losses and fatigue damage induced by wake-generated turbulence on the components. In this work, the possibility of wind turbine’s support structure cost reduction is explored by studying the effect on its design (and cost) caused by wake-generated turbulence. Furthermore, layout optimization considering wake losses and the wake-affected support structure cost was studied. To obtain insights about these effects, the turbulence intensity calculation and a simple support structure design were implemented into the wind farm design tool TeamPlay (by M. Zaaijer in the Wind Energy Research Group at TU Delft) and used to perform a series of case studies. The turbulence calculation was implemented following the IEC guidelines for any layout and wind direction distribution. The simple support structure design approach used in this work is based on two key aspects: (1) a base design obtained from Teamplay which does not account for fatigue and (2) the assumption of proportionality between fatigue equivalent load and turbulence. By using these tools, a location-specific support structure design within the wind farm was performed. Further, the weight and cost of the support structures was compared with the case in which all support structures have the same design obtained from the worst turbulence regime. It was found that wake-induced fatigue and its effect on the support structure design is not relevant for layout-spacing optimization because wake losses dominate the cost changes due to layout changes. Moreover, it was found that location-specific support structure design, according to their specific turbulence regime, would result in cost reductions that could account, as an upper limit, between 0.3 % and 0.7 % of the total capital costs in the studied cases. Finally, the cost reduction share of the total capital cost increases with increasing support structure size.

Windenergy

http://resolver.tudelft.nl/uuid:43da6232-92af-4e27-a011-0c43c3677255

Student theses

master thesis

(c) 2014 Russell A. Guzmán Tejada