【作者】 马志勇；

【导师】 徐鸿； 芮晓明；

【作者基本信息】 华北电力大学（北京） ， 热能工程， 2011， 博士

【摘要】 风能作为绿色可再生能源,已受到世界各国的广泛重视。叶片作为风电机组的核心部件,其设计理论和制造技术被视为风电机组研发的关键。目前,国内有关叶片结构设计研究仍然面临巨大挑战,深入开展相关基础理论与技术研究,对尽快掌握风电机组核心技术,提高自主创新能力具有重要意义。在此背景下,论文针对风电叶片结构设计方法及其关键技术展开研究。基于现有风电叶片设计基础理论,论文分析了叶片气动参数、结构参数的构成,探讨了相关坐标系的定义以及气动设计的常用方法。通过风电叶片构造分析,比较了强主梁叶片和弱主梁叶片的构造特点,分析了不同叶片承载结构的设计区别。研究了复合材料经典层合板强度理论、基于梁理论的等代设计方法在叶片承载结构设计中的应用。论文基于风特性的分析,给出了一种用于小尺度条件下风速、风向和湍流强度计算的脉动风工程计算模型,该模型可用于随机气动载荷的计算分析。对主要载荷计算方法、风况描述模型和机组运行状态进行探讨,分析了机组运行状态与外部风况的组合条件,确定了载荷计算所需最少设计工况。研究了风电叶片载荷时序仿真计算方法,采用统计外推法及Gumbel分布模型对含有随机成分的最大载荷进行统计分析,给出了叶片极限载荷计算方法。综合运用复合材料经典层合板理论、基于梁理论的等代设计方法,建立了叶片主要承载结构设计方法,并编制验证程序,进行实例计算,验证了方法的有效性。计算结果表明,采用复合材料经典层合板理论设计叶片结构铺层和采用基于梁理论的等代方法计算叶片层合板厚度都是可行的。通过对比分析,基于梁理论的等代设计方法更为简便,可为复合材料铺层计算提供依据,其中采用刚度条件的设计结果更为接近实际叶片,说明刚度在大型风电叶片结构设计中是关键约束。针对以往叶片气动与结构独立设计的问题,论文分析了厚度、实度和扭角等参数对叶片气动和结构性能的综合影响,给出了翼型沿叶片展向合理分布的气动结构平衡设计方法。该方法提出结构系数κ的概念,将大型风电叶片分为侧重结构强度的内圈与侧重气动性能的外圈,内圈采用钝后缘翼型以提高叶片结构强度和刚度,外圈采用薄翼型以提高气动性能,合理解决了气动性能与结构强度的矛盾。研究了叶片变桨中心位置设计方法,通过对扭矩载荷的分析,给出了叶片截面变桨中心与重心重合的设计方案,有利于减小叶片运行过程中的扭矩载荷。更多还原

【Abstract】 As an important part of green energy, wind power has been getting more and more attention in the world. Wind turbine blades are the main components of wind turbines, and their design and manufacturing technology are regarded as the key to wind turbine research and development. The researches on blade structure design are still faced with big challenges in China; therefore, a thorough study on relevant basic theories and techniques is of great significance to commanding the core techniques of wind turbines and improving our capacity for independent innovation. In the above context, a study featuring the design of wind turbine blade structure and relevant techniques is carried out in this dissertation.With theoretical analysis on the design of wind turbine blades, the author probes into the aerodynamic coefficients, structural parameters, definitions of relevant coordinates and the common aerodynamic design methods involved in wind turbine blade design. On the basis of analyzing the structure of wind turbine blades, the features of different blades are compared and the differences in bearing structure design between blades of strong spar and those of weak ones are studied. Besides, the author also conducts a strength analysis for laminated classic composite plates and applies the replacement methods of Beam theory into blade bearing structure design.Load calculation lays a foundation for wind turbine blade design. With a research on wind features, this dissertation offers an engineering calculation model involving wind turbulence such characteristic quantities as wind speeds, directions and intensity of a short period. This model can also be used for calculating random aerodynamic loads. Analyzing the main load calculating methods, description model of wind conditions, and system operating state, the author studies the combination conditions for wind system operating state and the external wind regime, and determines the minimum load design that may cover all the conditions for wind system operation. In addition, the author researches the timing simulation method, and conducts an analysis over the random components-contained maximum load with statistical extrapolation methods and the Gumbel distribution model, and finally generates the method for calculating the ultimate load of blade.With a comprehensive application of the classic laminated plate theory, the replacement design methods of Beam theory and some empirical formulas, a design method for the main load structure of blade is established, a testifying procedure is produced, a case analysis calculation is conducted, and the validity of design methods is justified. The calculation results show that both the way to design the blade structure layering with the theory of laminated classic composite plates and the method to calculate the thickness of blade laminated plates are feasible, the design method of Beam theory is more convenient and it can also lay a foundation for calculating composite layers, and the results obtained from rigidity design of replacement methods of Beam theory are closer to the real situation, which shows that the rigidity condition is one of the key constrained conditions in large-scale wind turbine blade structure design. As for the issue of blade structure optimization, the author builds a spar structure optimization model which takes into account of the curve and shear stress.As for the problem that the aerodynamic design and the structure design were conducted separately in the past, this dissertation offers an analysis of the overall influence of blade thickness, solidity and the torsion angle on aerodynamic and structure functions, and provides a balance design of aerodynamic and structure with reasonable distribution of extending airfoil shape of blade. This method initiates the concept of the structure coefficient ofк, and divides the large-scale blades into inner circles featuring structure requirements and out circles catering for aerodynamic requirements. The inner circles adopt the blunt trailing edge airfoil type to improve the structure strength and stiffness of the blade, while the out circles take the thin airfoil type with sound aerodynamic functions, to properly resolve the conflict between blade aerodynamic and structure. For the location design of the pitch center, this dissertation studies the blade torque load and produces a design scheme of coinciding the pitch center and the center of gravity in the cross section of blade. It can help reduce the blade torque load in operation.更多还原