【作者】 钱杰；

【导师】 周祖德； 胡业发；

【作者基本信息】 武汉理工大学 ， 机械电子工程， 2010， 硕士

【摘要】 风能是绿色可再生能源。在当今世界能源短缺,同时又突出强调环保的情况下,大力开发风能资源是普遍的趋势和潮流。降低风力发电机的启动风速可以更充分的利用风能资源,而叶片和主轴的支承是影响风力发电机启动风速的主要因素之一,由此开展对风力发电机叶片和主轴支承方式的研究具有重要的现实意义。介绍了几种叶片的设计理论,贝茨理论表明风力发电机的最大风能利用系数为0.593,至今都没有风力发电机能超过这个极限；介绍了叶素理论,通过叶素理论的假设条件推导出了叶素的受力情况和叶素上的轴向风轮转矩。介绍了涡流理论,涡流理论是经过风轮后以及风轮上方气流的漩涡与相似导线的磁场理论得到的,其结论和贝茨理论一致。在叶片的技术方面本文主要介绍了翼型的相关基本概念以及NACA系列翼型和风力发电机专用翼型,并利用CFD软件Fluent对两种NACA系列翼型进行了气动性分析,包括对压力场、速度场以及升阻比特性的对比分析,并对翼型进行了改进设计使其更能满足低风速启动的要求。将新翼型与原来的翼型进行对比分析,确定适合的翼型。根据贝茨理论,采用设计的翼型对叶片进行实体建模和有限元分析。为了降低风力发电机的启动阻力矩,在小型风力发电机中采用永磁轴承的支承方式。对永磁轴承进行有限元分析得到内外磁环之间的径向偏移对永磁轴承的径向力和轴向力的影响,根据分析结果对永磁轴承进行结构设计。通过两台采用不同支承方式的风力发电机的对比实验分析了磁悬浮支承对风力发电机启动阻力矩的影响。设计低风速小型磁悬浮风力发电机样机,主要分析了小型永磁悬浮风力发电机在装配时所遇到的问题和解决方法。装配永磁轴承时由于磁环产生的强大磁力,有必要设计出一套装配机构,并对永磁轴承的装配过程进行了详细介绍。简单介绍了整机的装配过程并对小型永磁悬浮风力发电机的结构特点进行了分析。更多还原

【Abstract】 Wind energy is green and renewable energy. To develop wind energy resources vigorously was a common trend in the case of the world’s energy shortages and emphasizing the environmental protection. Reducing the wind turbine’s start-up wind speed can fully exploit the wind energy. The blade and the bearing of the shaft was one of the criticality factors which can expanded the utilization of wind resources, so it had practical significance to research the blade of the wind turbine and the supporting way of the shaft.Some design theories of blade was introduced. The Betz theory indicated that the maximum wind energy utilization coefficient of wind turbine was 0.593, Till now there was no wind turbine could exceed this limit. Introduced the blade element theory, derived the force distribution and the axial torque of the element blade by the assumptions. Introduced the vortex theory,vortex theory was derived by the magnetic field theory and the air vortex which through the wheel and above the wheel, the result was equal with the Betz theory.The basic conceptions of the airfoils and the NACA series airfoils and the dedicated airfoils was introduced. The aerodynamic of two kinds of NACA series airfoils was analyzed by the CFD software Fluent, included the comparative analysis of the pressure field, velocity field and the Lift-drag ratio characteristics. The airfoil was improved as to satisfy the requirements of low wind speed start. The appropriate airfoil was determined by the comparative analysis between the NACA airfoil and the improved one. According to the Betz theory, The blade was modeled and element analyzed by used the improved airfoil.The magnetic bearings was used in the small wind turbine to reduced the start moment of resistance of the wind turbine. The influences of the radial force and the axial force by the radial offset was analyzed, the structural design of magnetic bearings was carried on by the analysis results. The influences of the wind turbine start moment of resistance by the magnetic bearing was analyzed through the comparative experiment about two wind turbines which used different kinds of bearing ways. The small magnetic wind turbine was designed, the problems and the solutions when assembling the small magnetic wind turbine was analyzed. As the magnetic rings produced strong magnetic force when assembling, it was necessary to design an assembly mechanism, the assembly process of magnetic bearings was introduced in details. The assembly process of the general was introduced and the structural features of the small magnetic wind turbine was analyzed.更多还原