A de-icing experimental investigation of blade airfoil for wind turbines based on external hot air method

Abstract

Wind turbines operating in cold and wet climates are prone to icing on the surface of their blades. It is necessary to develop effective de-icing methods for wind turbine blades. The commonly used blade de-icing method is heating, which includes the blade internal hot air method and the surface heating method. Recently, the use of external heat sources for blade de-icing has also received attention, such as the use of steam, infrared, and hot air, etc. In this research, the external hot air de-icing method for wind turbine blade was studied by experiments. A de-icing experimental system based on external hot air method was designed and established. The de-icing test was carried out on a blade segment with NACA0018 airfoil. The initial ice shape of blade airfoil was obtained by using an icing wind tunnel. The de-icing experiments were set up with four hot air temperatures and four hot air velocities. The deicing process was recorded by a high-speed camera, and the temperature changes on the blade surface are measured by an infrared thermal instrument. Furthermore, the de-icing time, de-icing area, de-icing rate and de-icing energy efficiency under different conditions were calculated and analyzed. According to the results, the external hot air method can effectively perform blade de-icing. The temperature and speed of the hot air have a significant impact on the de-icing process. Under the condition of this test, the maximum de-icing energy efficiency reached as 6.33 % at hot air temperature of 35 °C and velocity of 9 m/s. This study can provide a reference for solving the wind turbine blade icing problem by using external hot air de-icing method.