挟沙风作用下风力机叶片涂层冲蚀特性研究

Research on Erosion Properties of Wind Turbine Blade Coating Under the Wind-carrying Action

内蒙古中西部地区高频出现沙尘暴活动,风力机叶片涂层长期被挟沙风冲蚀磨损,导致风力机叶片涂层出现冲蚀坑和裂纹,缩短风力机叶片寿命。针对这一问题,利用自制的挟沙风试验台,采用气流挟沙喷射法对以环氧玻璃纤维板为基底的风力机叶片涂层进行低角度加速冲蚀磨损试验,用失重测量法测定冲蚀磨损量与冲蚀速度的关系,用扫描电镜(SEM)观测分析涂层表面的冲蚀形貌来确定冲蚀机理,并提出涂层冲蚀磨损程度的评价计算公式。结果表明:涂层的冲蚀磨损量随着冲蚀速度的增大而增加;低角度冲蚀以微切削冲蚀磨损作用为主,材料的硬度起着决定性作用,高角度冲蚀主要以挤压变形冲蚀磨损为主,材料的韧性起决定性因素,由于聚氨酯涂层材料是塑性材料,其韧性高而硬度低,故在低冲蚀角下冲蚀磨损量大;验证了评价计算公式用于评价涂层冲蚀磨损程度的可靠性,为运行在风沙环境下的风力机叶片涂层的改进提供理论依据。

Sandstorm activities frequently appear in the central western regions of Inner Mongolia and wind turbine blade coating has long been eroded by sand-carrying wind,leading to erosion pits and cracks in wind turbine blade coating and decay of the service life.This paper utilized airflow spray method to conduct the low angle erosion wear experiment of wind turbine blades with epoxy glass fiber board matrix by using the homemade carrying wind test bench.The relationship of erosion wear and erosion rate was obtained by weightloss measurement method,and the erosion morphology was observed by scanning electron microscope（SEM）,on the basis of which erosion mechanism and coating erosion degree′s evaluation formula were established.The results showed that erosion amount increased along with the increase of erosion rate.The micro cutting erosion wear was mainly resulted in the low angle erosion,in which the hardness of the material plays a crucial role.The extrusion deformation erosion was induced by the high angle erosion,whose key factor was the toughness of material.As polyurethane coating material belongs to plastic material,it possessed features of low strength and good toughness,thus the erosion became more serious when erosion angle was low.The reliability of the evaluation formula was verified by the evaluation method and it also provideds the theoretical basis for the improvement of wind turbine blade coating.