블레이드 팁 에어포일의 전연 부 손상이 풍력터빈의 연간발전량에 미치는 영향

Abstract

Blade damages such as contamination, erosion and icing are emerging as the major problem in these days. These phenomenons occur mainly at the blades tips which are exposed to wind with high angular velocity and it is evitable for wind turbine to prevent power loss without efficient planning of O&M (Operating and Maintenance). Therefore, systematic planning of O&M must be established by collecting the pertinent quantitative data for blade damages. This study analyzed the effect of damages at the leading edge of blade tip airfoil(NACA64618) on the aerodynamic performance through transient CFD simulation and AEP calculation was performed for NREL 5MW reference wind turbine to obtain the corresponding AEP loss. The CFD simulation result present ed different aerodynamic deterioration depending on the severity of damage conditions. The more severer the blade surface damages, the more aerodynamic performance was deteriorated. For the blade with various damage conditions at the leading edge of the airfoil, The range of lift coefficient reduction is from 1% to 53%, and the range of drag coefficient increase is from 34% to 314%, compar ed with those of a clean airfoil. The maximum rate of AEP loss under contamination conditions is 7.0% and that under erosion conditions is 6.8% and that under icing condition is 2%. The trend of AEP loss corresponded with reduction of lift-drag ratio at the lower-than-rated wind speed conditions. However, such a trend was not seen at the higher-than-rated wind speed conditions due to the pitch control system of the wind turbine. Overall, the calculated AEP loss ranged from 2% to 7.0% depending on the extent of damage at the leading edge.