Metoder att förhindra nedisning av vindkraftverksblad
ABSTRACTMany wind turbines have problems with icing and there is still no effective method to de-ice without stoppage of production and power loss. Here I therefore consider other methods than those available today, and particularly, I consider how these methods could be applied to wind turbines of the company Oxel. A surface where the water droplets do not attach might be the basis for a useful method. If no water attaches, no ice could form. To accomplish this a hydrophobic surface is nessesary, for example wax. My work is therefore mostly about superhydrofobic surfaces, since the production of totally frictionless surfaces is not yet a possibility. There are different ways to create the so called Lotus effect with superhydrophobicity on a surface. One way is to start with a material with low surface energy and create micro and nanostructures upon it to make it ?rough?. Another way is to take an already rough surface and modify it with a low surface energy material. The outer layer on Oxel´s wind turbines are made of lexanplastic. To find out how the surface looks like atomic force microscopy has been used, we also made measurements of the contact angle on the plastic. Through these examinations we have come to the conclusion that lexanplastic has similar topography as glass, the plastic is also hydrophobic but not superhydrofobic. Many of these methods are still probably too expensive to be able to apply to the wind turbines.