Preparation Of Electrothermal Super-hydrophobic Coating For Wind Turbine Blades And Research On Its Anti-deicing Performance

Clean energy is one of the first breakthroughs in my country’s establishment of a sound green and low-carbon circular development economic system.Wind energy,as an important clean energy,has developed rapidly under the support of national policies.However,wind farms in the southwest and other regions have seriously affected wind turbines.Stable and safe operation.At present,electric heating ice melting technology is considered to be a reliable means to solve the problem of wind farm icing.Super-hydrophobic coating anti-icing technology is favored by operators because of its ease of implementation.However,in electric heating technology,the installation of electric heating elements on the surface of the blade has a certain impact on its aerodynamic performance.The wear resistance and poor weather resistance of super-hydrophobic coatings restrict its development and application.Based on the above research background,in this paper,a superhydrophobic coating with good wear resistance and weather resistance and conductive function was prepared by self-assembly precipitation method,and the basic performance of the coating was tested.The electrothermal superhydrophobic coating was applied in an artificial icing environment.The anti-icing experiment of the small wind turbine of the layer was carried out,the electric heating ice melting experiment was carried out on the coating,and the physical process of the electric heating ice melting of the coating was studied.The research in the thesis can provide a reference for the application of electrothermal super-hydrophobic coatings in wind turbines.The main work and achievements of the thesis are as follows:(1)The carbon nanotube electrothermal superhydrophobic coating was prepared by the solution blending method and the self-assembly precipitation method,and the influence of different preparation processes on the coating electrothermal superhydrophobic performance was discussed.The results show that the coating prepared by the solution blending method has better conductivity and hydrophobicity,but it has higher requirements for inorganic content and environmental temperature,and is prone to dry cracking and weak adhesion to the substrate.The static contact angle of the sample prepared by the self-assembly precipitation method is 148～162°,the rolling angle is 4.3～7.6°,and the volume conductivity is 0.5～12.5 S/m;the static contact angle of the sample prepared by the solution blending method is 153～ 158°,the rolling angle is 6.8～12.6°,and the volume conductivity is 2.17～5.28 S/m.(2)The electrothermal super-hydrophobic coating prepared by the self-assembly precipitation method was used as the research object,and the acid and alkali resistance,high and low temperature resistance,ultraviolet aging resistance and abrasion resistance were tested.After 14 days of acid and alkali resistance,high temperature resistance,and UV aging resistance,the performance test was carried out.The results showed that the sample can still maintain superhydrophobic characteristics and electrical conductivity,and has good electrical conductivity and hydrophobic stability.(3)The anti-icing performance test of the electrothermal super-hydrophobic coating was carried out.The results show that with the increase of the number of "icing-deicing" cycles,the lateral cohesive force of the coating decreases first,then increases and then slowly decreases,and then stabilizes to about 32 k Pa,which has a good and relatively stable phobicity.Ice performance;in a constant temperature environment of-5°C,the freezing delay time of water droplets on a hydrophobic surface is nearly 90 s longer than that of a non-hydrophobic surface,and the freezing time is nearly 180 s longer,and the prepared coating has a certain delay ice coating effect;The longer the freezing time of the coating surface is,the greater the damage to the hydrophobic performance;the uniform temperature distribution of the coating surface during electric heating,and the good heating uniformity(4)The anti-icing/melting test of small wind turbine blades coated with electrothermal super-hydrophobic coating was carried out,and the icing morphology that appeared during the icing process was divided into three types;the super-hydrophobic characteristics of the blades in the early stage of icing were proposed Effectively delay the formation of ice coating;the synergistic effect of electric heating and super-hydrophobic properties makes the coating have better anti-icing and ice melting effects.(5)Based on the three ice coating morphologies,a numerical calculation method for the ice melting of the electrothermal super-hydrophobic coating was established and verified by experiments.The results show that at the same ice thickness,the electrothermal superhydrophobic coating has a special shape,and its melting power is slightly higher than that of the non-superhydrophobic coating;the established electrothermal superhydrophobic coating has a critical ice melting power density The numerical calculation results are basically consistent with the experimental results;the ice shedding during the ice melting process of the electrothermal superhydrophobic blades under rotating conditions is calculated,and the analysis shows that the low bonding strength of the superhydrophobic coating and the ice layer promotes the fracture and shedding of the melted ice layer.