Experimental Study On The Wind Turbine Blade Icing Based On High Speed Photography

When the wind turbine installation in extremely cold areas, wind turbine blade surface plot will produce ice, frost and other phenomena, thus affecting the performance of wind turbines, serious cases causing damage to the unit, and even cause accidents.Therefore, the study and analysis of wind turbine blades ice surface becomes very important.This study icing wind tunnel experiment method, the icing wind turbine blade surface under different conditions were studied.For the law of wind turbine blades ice surface on the use of NACA0018, NACA7715, NACA5520three wind turbine blade airfoil wind tunnel experiments conducted research icing, the two experiments were selected velocity, respectively, U=3m/s and U=6m/s.Application of high-speed imaging device for recording the test section, and the collection and processing of information by computer.Sprinklers water drop test section diameter controllable installed outdoor cold air is sucked wind tunnel and along with blowing leaves supercooled water droplets collide icing.Test the situation leaves the table angle of attack leaves under different wind speeds and ice distribution; changing period adjacent blade surface freezing rate. Analysis of wind speed, temperature and other environmental factors, airfoil, angle of attack, their leaf surface temperature of the blade surface ice distribution factors affect the growth rate. The main findings are as follows:1) Different effects on the leaf surface wind speed icingIn both wind speed, for NACA0018, NACA5520, NACA7715airfoil wind icing three experiments for both wind speed distribution on the blade surface of the ice, the rate of freezing at the wind blade leading edge, a side surface of the blade icing cross-sectional area were measured and analyzed wind speed U=3m/s and U=6m/s at the forefront of the wind vane at the freezing point rate compared,3m/s greater than6m/s; wind vane in a way that can affect distribution of surface ice.2) Effect of different angle of attack on the blade surface freezing Icing blade surface, the wind began to emerge from their point of ice, over time, the ice thickens.Due to the different angle of attack of the blades into the wind, ice distribution varies.The experiment of two seven kinds selected angle, namely α=0°,α=10°,α=-10°,α=20°,α=-20°,α=30°,α=-30°.In these seven kinds of angles, for NACA0018, NACA5520, NACA7715three kinds of airfoil icing wind experiment, these seven kinds of the same angle, the blade surface ice distribution, ice blade leading edge upwind speed, blade surface junction a side cross-sectional area of the ice was measured and analyzed in the angle of attack between-30°-30°changes, either positive or negative angle of0°as a reference, the deflection angle of attack is small, the total leaf surface area of small ice; big deflection angle of attack, the total area is too large blade surface icing.In addition, the use of wind tunnel experiments on wind turbine shroud icing were tested and analyzed-Experimental droplets flow of two kinds:0.5L/min and1L/min, wind speed is nine kinds, from4m/s-12m/s, interval1m/s.From4m/s-12m/s, spaced1m/s. The shroud experiments under different icing conditions distribution, flow rate of water droplets in the same case, as the wind speed increases, the rate of freezing of the shroud was an increasing trend; wind speed in the same conditions, the flow of large droplets freezing rate than under the shroud of large droplets flow, and this trend is more obvious at low wind speeds.The results of this study may be effective in preventing the development of leaf surface icing, structure and materials and wind turbine shroud his icy parts provide the technical basis to provide theoretical and experimental basis for the development of resistant to cold weather conditions of wind turbine.