Biochar-Polypyrrole Coating Preparation And Wind Turbine Blade Anti-Icing Test Study

In the context of the "Carbon peaking,carbon neutral" new opportunities are provided for the development of renewable energy.Wind energy has attracted increasing attention as a renewable energy source.However,in high latitude and high altitude areas where wind energy resources are superior,wind turbines often encounter catastrophic weather like a cold waves and frost.This leads to the formation of ice on the surface of the wind turbine blades,which reduces the efficiency of electricity production and even leads to accidents,so the problem of defrosting wind turbines should be urgently studied.The use of hydrophobic coatings on the surface of objects can accelerate the disappearance of water droplets and reduce the likelihood of freezing,thus delaying ice formation,but the effects of using hydrophobic coatings on wind turbine blades have not yet been fully investigated.To investigate the anti-icing effect of hydrophobic coatings on wind turbine blades,in this paper,waste cow manure digestate was obtained by anaerobic fermentation,and the digestate biochar material was produced by pyrolysis.Polypyrrole was loaded on biochar to produce biochar/polypyrrole material with excellent performance,and the hydrophobicity of biochar/polypyrrole was investigated by studying the biochar of digestate,and the hydrophobic coating of biochar/polypyrrole was prepared and coated on the blade surface to investigate its anti-icing performance,and the following research work was carried out:(1)The biochar material was prepared from waste anaerobic fermented cow dung digested by high-temperature charring treatment,and the biochar/polypyrrole material was obtained by loading polypyrrole on the surface of biochar by chemical oxidation.The materials were characterized by Fourier infrared spectroscopy(FTIR),scanning electron microscopy(SEM-EDS),X-ray photoelectron spectroscopy(XPS),and other characterization methods.The analysis results show that the porous structure,irregular shape on the surface of the biochar/polypyrrole material can constitute a rough structure with superhydrophobic structure.(2)Biochar,biochar/polypyrrole material,and polydimethylsiloxane(PDMS)were ultrasonically mixed and sprayed on the blade surface by spraying method.Five different concentrations of biochar/polypyrrole material were tested for hydrophobicity and anti-icing to determine the best concentration of hydrophobic material and used for the next wind tunnel test study.The hydrophobic properties of the materials were analyzed by contact angle test,and the contact angle of the biochar coating was 121.18 °,which showed hydrophobic properties.The contact angle of the biochar/polypyrrole coating was 151.94 °,and when the biochar/polypyrrole coating was in contact with water droplets,the air retention area could reach 92.3%,showing superhydrophobicity.(3)The anti-icing performance of biochar and biochar/polypyrrole coatings was tested by icing wind tunnel test system.The results showed that both biochar coating and biochar/polypyrrole coating had an anti-icing effect,and the anti-icing effect of biochar/polypyrrole coating was the best.,the icing mass of biochar/polypyrrole coating can be reduced by 66.65% and the maximum icing area by 55.29%relative to the uncoated blade.The superhydrophobic coating can achieve a certain anti-icing effect on the blade by reducing the capture of overcooled water droplets on the blade surface and retarding the freezing of overcooled water droplets.The results of the ice bond strength test and stability test on the hydrophobic materials showed that the ice bond strength of biochar coating and biochar/polypyrrole coating was reduced by 42.71% and 64.79% compared with uncoated blades.It proves that the coated blade is easier to de-ice,biochar from digestate,and biochar/polypyrrole can reduce the ice adhesion on the blade surface with good hydrophobicity and anti-ice performance.The stability test results showed that the abrasion test caused damage to the material but still maintained hydrophobicity,and the material has good stability.