Study On The Application Of Carbon Fiber In Anti-icing And De-icing Of Wind Turbine Blades

Carbon fiber materials are widely used in aircraft manufacturing,shipbuilding,automobile manufacturing and other fields because of their advantages such as light weight,high strength,excellent heat conduction and good electrical conductivity.Based on its excellent electrothermal performance,domestic and foreign scholars have made preliminary research on its application in ice melting of conductors and wind turbine blades,and made some progress.At present,the research on the application of carbon fiber materials in ice melting on wind turbine blades is still less,and the technology is not yet mature.Therefore,designing a complete technical scheme of carbon fiber wind turbine blade ice melting is of great academic significance and practical value for preventing and eliminating the ice coating of wind turbine blades and reducing the icing disaster of wind farms.Firstly,the calculation model of the critical ice / deicing power density of wind turbine blade is set up,and the carbon fiber heating element with multilayer material structure is designed,and the icing characteristics of wind turbine blades are analyzed.At the same time,two kinds of wire based on the distribution law of the critical ice protection power density on the blade of the wind turbine are put forward.A uniform layout of partitioned anti icing / de icing schemes is carried out and the performance of each scheme is tested.The main work and achievements of this paper are as follows:(1)The calculation model of the critical ice / deicing power density of the wind turbine blade was established,and the variation of the critical ice / deicing power density under different parameters was analyzed,and the test was carried out.The results show that the critical ice prevention power density increases with the increase of the impact coefficient,the string length and the relative wind speed,and decreases with the increase of the ambient temperature,and the critical ice removal power density decreases with the increase of ice thickness,the chord length of the airfoil and the ambient temperature,and increases with the increase of the wind speed.(2)The structure of carbon fiber heating element with multilayer structure is designed.The structure consists of heat insulation layer,heating layer,heat conduction layer and protective layer.The calculation method of the equivalent resistance of carbon fiber heating element with multilayer structure is deduced.The calculation results are in agreement with the test results.The space of the silk beam is 2mm,3mm,4mm and 5mm,respectively.The resistance temperature stability test of the fiber heating ele ment shows that the resistance of the heating element varies slightly with the temperature during the heating process.It is considered that the heating element has a good resistance to temperature stability,and the carbon fiber heating element will lead to the presence of air gap,melting ice water and osmosis area in the process of deicing the carbon fiber heating element.The power density of the critical deicing is increased.(3)When the thickness of the heat conduction layer increases,the maximum temperature difference between the ice layer and the blade interface decreases during the deicing of the heating element,and the maximum temperature difference of the interface decreases when the thermal conductivity of the heat conduction layer increases.When the thickness of the heat conduction layer is 0.5mm and the thermal conductivity is 3.5W/m2,the effect of the distance of the wire beam on the interface of the ice layer is analyzed by the finite element method.It is suggested that the distance of the tow in the process of deicing of the heating element should be within 1mm~8mm.(4)According to the icing characteristics of the wind turbine blades and the distribution of the critical ice protection power density on the blade of the wind turbine,two layout schemes for the carbon fiber heating element on the blade are proposed: the layout of the wire bundle arrangement and the arrangement of the string arrangement and the arrangement of the string.The results of the two kinds of zoning scheme are tested.The results show that the current of the tow direction arrangement scheme is much larger than that of the tow chord arrangement under the same heating power density,and it produces a lot of Joule heat on the contact resistance in the ice prevention system.Therefore,from the point of view of reducing energy consumption,it is recommended to use the tow arrangement of the tow.