叶片覆冰对风力发电机气动性能和功率特性的影响

As the exploitation of wind power in southern mountainous area of China, the icing problem of wind turbine blade is becoming more and more common, which has a significant influence on its aerodynamic performance and generating efficiency. However, at present, researches relating the icing aerodynamic performance have mainly focused on the two dimensional numerical simulation, due to the lack of experimental verification, the accuracy of those simulation remain controversy. Based on the 300kW wind turbine and artificial icing wind tunnel that established in Xuefeng Mountain Natural Icing Station, this project is going to experiment the change law of aerodynamic performance and power output in different ice type. Building up three-dimensional simulation model considering the wind wheel rotation effect by applying the theories of hydrodynamics and aerodynamics, analyzing and revealing the icing parameters’ (icing-type, icing-thickness, icing-distribution) influence on wind blade’s aerodynamic performance; Moreover, active pitch-regulated strategy is proposed to raise the wind turbine’s output power, studying the key area of a wind turbine blade that affect its output power, thus provide basis for anti-icing and de-icing. Hence, with the rapid growth of wind power in south China humidity regions, this project will provide basis for wind power equipment’s anti-icing design, manufacture and operation in humidity region’s wind farm, has important academic value and meet the urgent requirements of engineering application.

随着我国南方山地风电资源的相继开发，风电场风力机叶片覆冰现象越来越普遍，严重影响叶片的气动性能及风力机发电效率。目前对风力机叶片覆冰气动性能的研究主要集中在二维数值仿真方面，由于缺乏试验验证，其准确性还有待于考证。本项目利用雪峰山自然覆冰试验基地建立的300kW风力发电机及人工冰风洞，试验研究风力机叶片在不同覆冰状态下气动性能及发电功率的变化规律。采用流体力学、空气动力学等方法，建立考虑风轮旋转效应的覆冰叶片三维气动性能仿真模型，分析揭示覆冰类型、覆冰厚度、覆冰分布等覆冰参数对风力机叶片气动性能的影响规律；在此基础上，提出提高覆冰风力机发电功率的主动变桨策略，从气动性能的角度研究覆冰后影响风力机发电功率的叶片关键区域，为叶片防冰除冰策略提供依据。在我国南方高湿地区风电高速发展的背景下，本项目研究将为风电装备防冰设计、制造和高湿地区风电场运行提供依据，既具有重要的学术价值，也具有工程紧迫性。

随着我国南方山地风电资源的开发，风力机叶片覆冰现象越来越普遍，严重影响叶片的气动性能及发电效率。目前对覆冰风力发电机的气动性能研究主要集中在二维数值仿真方面，由于缺乏试验验证，其准确性还有待于考证。本项目严格按照项目计划书要求展开工作，并达到了相应的目标。本项目在二维仿真基础上，建立风机叶片三维旋转仿真，分析覆冰参数对叶片气动性能参数的影响规律；同时，在自然覆冰试验基地及人工冰风洞，根据自主研究发明的气动参数测量装置和覆冰监测方法，探究了风机叶片的覆冰规律和影响因素，并且获得不同覆冰情况对风力发电机气动性能的影响规律；验证并优化气动性能计算模型，提出通过变桨控制提高覆冰条件下风力机发电功率的方法；最后，通过试验及仿真结果，确定了风力发电机叶片的重点防冰区。研究发现：覆冰会严重影响风机叶片的气动性能，相比雾凇覆冰，雨凇覆冰的影响更严重；相比流线冰，角状冰对风机叶片的气动性能影响最严重。随着覆冰程度的增加，风机叶片的切向力逐渐减小，法向力逐渐增加，最佳叶尖比减小，风能利用率降低，输出功率降低。根据仿真以及试验发现，风机叶片叶尖处覆冰对气动性能影响最严重，并以此为依据，指出风机叶片叶尖处为重点防冰保护区域。