基于NURBS的螺旋转子型线补偿设计与优化

发布时间：2017-12-30 18:36

本文关键词：基于NURBS的螺旋转子型线补偿设计与优化　出处：《中南大学》2012年硕士论文　论文类型：学位论文

【摘要】：螺杆压缩机广泛应用于矿山、冶金、机械和制冷行业。螺旋转子是螺杆压缩机的核心部件,其型线对压缩机的性能具有很大影响。螺旋转子发生力、热变形将会引起功耗及泄漏损失,导致螺杆压缩机工作效率降低。本文采用NURBS方法对转子型线进行补偿设计与优化,以减小工作过程中转子型线与理想型线的误差,提高螺杆压缩机工作性能。首先对螺旋转子的坐标变换、典型型线方程及螺旋齿面方程进行理论分析,为螺旋转子的三维参数化建模与型线补偿设计提供理论依据。根据NURBS曲线理论,推导螺旋转子型线的NURBS表达式,并确定了节点矢量、控制顶点和权因子的计算方法。在分析研究各种参数化设计原理及技术基础上,设计一种基于NURBS和SolidWorks的螺旋转子三维参数化建模方案,并以SolidWorks API为二次开发工具,实现了螺旋转子的三维参数化设计。对螺旋转子的运行工况进行了深入分析,利用Solidworks Simulation对其分别进行受力变形和热态变形的有限元分析,通过在螺旋转子工作型面上建立虚拟传感器,获得转子工作状态下的变形分布规律。对螺旋转子的受力变形和热态变形进行分析比对,为转子的补偿设计提供可靠数据。为了补偿实际工况下的转子型线与理想型线的误差,推导变形型线和标准型线间的误差计算理论公式,并以该误差为依据,构造两种误差补偿方案(反向补偿和法向补偿)。对转子型线进行迭代补偿,优化转子型线。以标准原始对称阴、阳转子为实例,证明了补偿方案的有效性。
[Abstract]:Screw compressor is widely used in mining, metallurgical, mechanical and refrigeration industries. Screw rotor is the core component of screw compressor, and its profile has great influence on the performance of compressor. Thermal deformation will cause power loss and leakage loss, which will reduce the efficiency of screw compressor. In this paper, the NURBS method is used to compensate the rotor profile design and optimization. In order to reduce the error between rotor profile and ideal profile, and improve the performance of screw compressor. Firstly, the coordinate transformation, the typical profile equation and the helical tooth surface equation of the helical rotor are analyzed theoretically, which provides the theoretical basis for the 3D parametric modeling and the profile compensation design of the helical rotor. According to NURBS curve theory, the NURBS expression of helical rotor profile is deduced, and the calculation method of node vector, control vertex and weight factor is determined. Based on the analysis and study of various parameterized design principles and techniques, a 3D parametric modeling scheme of spiral rotor based on NURBS and SolidWorks is designed. Using SolidWorks API as the secondary development tool, the 3D parametric design of spiral rotor is realized. The operating conditions of spiral rotor are analyzed in depth, and the finite element analysis of stress deformation and hot deformation is carried out by Solidworks Simulation. By establishing a virtual sensor on the working surface of the spiral rotor, the deformation distribution law of the rotor is obtained, and the stress deformation and the thermal deformation of the spiral rotor are analyzed and compared. Provide reliable data for rotor compensation design. In order to compensate the error between the rotor profile and the ideal profile under the actual working condition, the theoretical formula of error calculation between the deformation profile and the standard profile is derived, and the error is taken as the basis. Two kinds of error compensation schemes (reverse compensation and normal compensation) are constructed. The rotor profile is compensated iteratively to optimize the rotor profile. The effectiveness of the compensation scheme is proved by taking the standard primitive symmetric shaded and positive rotors as examples.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH45

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