【作者】 周燕；

【导师】 刘河洲； 徐新华；

【作者基本信息】 上海交通大学 ， 材料工程（专业学位）， 2021， 硕士

【摘要】 在寒冷地区或南方湿冷风场安装的风力发电机冬季运行时常遭受结冰气候的严重影响。风机叶片结冰会改变气动外形和载荷分布,降低发电功率,影响运行安全。叶片防冰、除冰技术一直是风电行业的重要课题。其中,电热防冰具有高能效、可设计性强及高可靠性等优势,成为叶片防冰的主要技术路径之一。本课题针对风机叶片在低温、湿冷南方风场的结冰问题,提出叶片壳体前缘预埋碳晶电热膜的防冰方法。计算叶片防冰功率,设计和制备碳晶电热膜复合结构并考察这种结构的电热行为和力学性能。论文的主要研究内容和结果如下:(1)采用有限元分析软件,建立风机叶片简易模型,仿真计算了风场工况环境下维持叶片防冰状态时的供给功率下限;仿真计算了无风、不运行条件下,叶片材料耐温性限定的供给功率上限。设计了防冰叶片功率分布图,为防冰叶片制造提供碳晶电热膜设计依据;制备了碳晶电热膜夹芯板并在两种实际环境中测试了升温曲线,仿真计算结果与之比较分别偏高16.5%和18.5%,这是试验环境散热效果无法完全模拟风场环境所致。(2)针对碳晶电热膜无法在真空灌注工艺中渗透树脂的问题,设计构造了开槽通道,并对开槽间距、灌注方向进行了试验研究,通过对灌注后板材树脂含量分布状态的考察,优化开槽尺寸与开槽灌注方向,并得到良好的灌注效果,提供碳晶电热膜引入叶片制造的工艺方法。(3)对碳晶电热膜引入叶片铺层后对叶片蒙皮玻璃钢板和叶片壳体夹芯板的力学性能的影响进行了试验研究。结果表明,碳晶玻璃钢弯曲性能略有提升,而拉伸强度因为电热膜和玻璃钢的界面问题下降约6%,但仍满足叶片设计要求且不影响壳体夹芯复合构件的弯曲性能。碳晶夹芯复合结构的面层强度提高7.72%,夹芯板复合结构弯曲强度提升16.35%,且失效模式均未发生改变。(4)针对在应用中“低温结冰-高温加热”的苛刻服役条件,对壳体碳晶电热玻璃钢板循环加热后的尺寸变化和力学性能变化进行了研究,结果显示,碳晶电热玻璃钢板循环加热250次厚度无变化,循环加热100次力学性能无变化,碳晶电热膜防冰复合结构具有良好的热循环稳定性。根据以上研究结果,碳晶电热膜复合结构的设计可以满足叶片防冰的应用需求。更多还原

【Abstract】 Wind turbines installed in cold and wet wind farm are often severely affected by freezing weather in winter.Icing on wind turbine blades will change aerodynamic shape and load distribution,reduce power generation and affect operation safety.Blade anti-icing and de-icing technology has always been an important topic in wind power industry.And electric heating anti-icing method has become the main technical paths for the advantages of high energy efficiency,strong design ability and high reliability.In view of blade icing problem on wind farm in south of China,this paper proposes an anti-icing method of carbon crystal electro thermal panel embedded in leading edge of blade.The anti-icing power of blades was calculated,the composite structure of carbon crystal electro thermal panel was designed and fabricated,and the electro thermal behavior and mechanical properties of the structure were investigated.(1)The ansys software was used to establish a simple model of the blade,and the lower limit of power supply when the blade was maintained in the antiicing state in the conventional environment was calculated.The upper limit of power supplied by the temperature resistance of the blade material under the condition of no wind was calculated.The power distribution diagram of antiicing blade was designed for the manufacture of anti-ice blade.Carbon crystal sandwich panel was prepared and the heating curve was tested in two kinds of actual environments.The simulation results were 16.5% higher and 18.5% higher than test results,which was due to the fact that the heat dissipation effect of the test environment could not fully simulate the wind farm.(2)Designed grooves on carbon crystal electro thermal panel in the vacuum infusion process for resin flow.Grooves span and infusion direction were researched,based on resin content and sample inspection,obtain good infusion effect for optimization of grooves span and infusion direction.These results provide the introduce method for carbon crystal electro thermal panel.(3)Experimental study was carried out on the influence of carbon crystal electro thermal panel on the mechanical properties of blade skin and blade shell.The results show that the bending performance of carbon crystal FRP is slightly improved,and the tensile strength is reduced by about 6% due to the interface problem between the electro thermal panel and the FRP,but the bending performance of the sandwich composite still meets the design requirements of the blade and does not affect the shell sandwich composite.The skin FRP strength is increased by 7.72%,and the bending strength of the sandwich is increased by16.35%,and the failure mode is not changed.(4)In view of the harsh service conditions of "low temperature icing-high temperature heating" in the application,the size change and mechanical properties change of carbon crystal sandwich composites after cyclic heating were studied.The results show that the thickness of carbon crystal sandwich has no change after being heated for 250 times,and the mechanical properties have no change after being heated for 100 times.It has good thermal cycling stability.According to the above research results,the design of carbon crystal electro thermal composite can meet the application requirements of blade anti-icing.更多还原