风力发电机叶片优化设计方法研究

发布时间：2018-01-09 10:28

本文关键词：风力发电机叶片优化设计方法研究　出处：《浙江大学》2014年硕士论文　论文类型：学位论文

【摘要】：面对迫在眉睫的能源和环境危机,作为当前可再生能源技术中,相对成熟并同时具备商业开发和规模发展的一种清洁能源—风能,它的利用方式和发电技术的发展受到世界各国越来越多的关注。风力发电机是风能利用的核心,水平轴风力发电机是风力发电机主要类型之一。叶片是水平轴风力发电机的关键部件,风力发电机的风能利用效率与叶片形状密切相关,所以叶片的设计与优化是风力发电机设计制造中的重要工作内容。论文分析了国内外风力发电机叶片研究现状、风力发电机叶片设计理论和方法以及叶片转矩、风能利用系数、受力系数等计算方法。论文根据叶素动量理论建立了风力发电机叶片气动计算模型,针对400KW风力发电机叶片,使用Matlab语言编制了叶片气动性能计算程序,计算得到叶片的效率值。综合叶片翼型厚度变化影响和变桨距设计要求,提出了一种新的叶片优化设计方法,使用Matlab工具基于叶素-动量理论开发的优化设计程序,以提高风力发电机叶片年平均风能转换效率为优化设计目标,以翼型相对厚度和桨距角为设计变量,利用遗传算法,对叶片形状和尺寸进行多参数优化设计。论文提出的一种新的大型风力发电机叶片设计方法,包含四个阶段：第一阶段是叶片翼型气动系数的获取,通过naca、Xfoil和AirfoilPrep三个软件有机结合得到攻角区间在-180°～180°内的翼型气动系数；第二阶段是叶片基本参数的设定,通过风力发电机叶片设计理论计算得到风力发电机的功率、风轮直径、叶尖速比、叶片数、实度等；第三阶段是采用Wilson法得到初步设计的叶片,通过Matlab编写叶片效率的计算方法程序,进行初始叶片截面弦长和扭角的计算,从而得到初始叶片的效率值；第四阶段是得到优化后的两组叶片,基于Wilson方法设计结果,利用遗传算法,在个体适应度计算时考虑叶片沿展向的相对厚度的变化,得到优化后的叶片参数；最后综合考虑叶片厚度相对于桨距角发生变化的情况下,再对叶片进行优化,得到进一步优化的叶片参数。仿真结果表明,在不同的风速下,通过论文提出的优化方法得到的叶片,比原有叶片的风能转换效率都有所增加,从而验证了论文提出的优化方法的有效性。本文研究主要放在大攻角范围下翼型气动系数的获取,基于叶片翼型相对厚度变化的优化设计方法,进而提出了综合考虑叶片翼型厚度相对于桨距角发生变化的情况下的优化设计方法。
[Abstract]:Facing the imminent energy and environmental crisis, as the current renewable energy technology, relatively mature and has commercial development and scale development of a clean energy-wind energy. Its utilization mode and the development of power generation technology are paid more and more attention in the world. Wind turbine is the core of wind energy utilization. Horizontal axis wind turbine is one of the main types of wind turbine. Blade is the key component of horizontal axis wind turbine. The wind energy efficiency of wind turbine is closely related to the shape of blade. So the design and optimization of blade is an important part of wind turbine design and manufacture. This paper analyzes the research status of wind turbine blade at home and abroad, the design theory and method of wind turbine blade, blade torque and wind energy utilization coefficient. According to the theory of blade momentum, the aerodynamic calculation model of wind turbine blade is established, aiming at 400KW wind turbine blade. The calculation program of blade aerodynamic performance is compiled by using Matlab language, and the blade efficiency value is calculated. The influence of blade airfoil thickness variation and the design requirements of pitch of variable propeller are considered. In this paper, a new method of blade optimization design is proposed, and an optimal design program based on the theory of leaf element and momentum is developed by using Matlab tool. In order to improve the average annual wind energy conversion efficiency of wind turbine blade, the relative thickness of airfoil and pitch angle are taken as design variables, and the shape and size of blade are optimized by genetic algorithm. A new design method for large wind turbine blades is proposed in this paper, which consists of four stages: the first stage is to obtain aerodynamic coefficients of blade airfoil through naca. The aerodynamic coefficients of the airfoil in the angle of attack range of -180 掳~ 180 掳are obtained by the combination of Xfoil and AirfoilPrep software. The second stage is to set the basic parameters of the blade. The power of the wind turbine, the diameter of the wind turbine, the ratio of blade tip speed, the number of blades, the degree of reality and so on are calculated by the design theory of wind turbine blade. In the third stage, the primary design blade is obtained by Wilson method, and the initial blade section chord length and torsion angle are calculated by Matlab program. The efficiency value of the initial leaf was obtained. In the 4th stage, two groups of blades were obtained after optimization. Based on the design results of Wilson method and genetic algorithm, the relative thickness of blade along the span direction was considered in the calculation of individual fitness. The optimized blade parameters were obtained. Finally, considering the change of blade thickness relative to pitch angle, the blade parameters are optimized. The simulation results show that under different wind speeds, the wind energy conversion efficiency of the blade obtained by the optimization method proposed in this paper is higher than that of the original blade. Thus, the effectiveness of the proposed optimization method is verified. In this paper, the aerodynamic coefficients of the airfoil are obtained in the range of large angle of attack, and the optimization design method based on the relative thickness of the blade airfoil is presented. Furthermore, an optimal design method considering the change of blade airfoil thickness relative to the pitch angle of propeller is put forward.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315

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