基于分层模态综合法的大型汽轮发电机组转子-末级叶片耦合系统扭转振动分析

发布时间：2018-09-12 08:39

【摘要】：针对应用三维有限元法计算大型汽轮发电机组转子-末级叶片耦合系统扭转振动时存在自由度多和难以实现等问题,在模态综合法(CMS)的基础上,推导了计算转子-末级叶片耦合系统振动的分层二重CMS法的基本方程,给出了降阶的思路和原理.采用该方法对某1 000 MW汽轮发电机组的转子、末级和次末级叶片组成的耦合系统进行了扭转振动特性计算和分析,与不考虑末级、次末级叶片实际结构影响的固有振动特性进行了对比.结果表明:如果不考虑末级叶片的实际结构,会漏掉一些重要的振动模态,给转子和叶片的安全带来隐患;降阶前系统的自由度达到1.5亿,而降阶后系统的广义自由度仅为原自由度的0.07%;分层二重CMS法可用于大功率机组转子、末级、次末级耦合系统的扭转振动分析.
[Abstract]:In order to solve the problems of many degrees of freedom and difficulty to realize the torsional vibration of the rotor-last-stage blade coupling system of large turbine-generator set by using three-dimensional finite element method, the modal synthesis method (CMS) is used to solve the problem. The basic equations of the layered double CMS method for calculating the vibration of the rotor-final blade coupling system are derived, and the idea and principle of reducing the order are given. This method is used to calculate and analyze the torsional vibration characteristics of the coupled system composed of the rotor, the last stage and the secondary stage of a 1 000 MW turbine-generator set. The natural vibration characteristics of the actual structure of the secondary stage blade are compared. The results show that if the actual structure of the final stage blade is not considered, some important vibration modes will be missed, which will bring hidden trouble to the safety of rotor and blade, and the degree of freedom of the system before reducing the order can reach 150 million, The generalized degree of freedom of the reduced system is only 0.07 of the original degree of freedom, and the layered dual CMS method can be used to analyze the torsional vibration of the rotor, the last stage and the second stage coupling system of the high-power unit.
【作者单位】：西安交通大学机械结构强度与振动国家重点实验室;东方汽轮机有限公司;
【基金】：国家973计划资助项目(2011CB706505) 国家自然科学基金资助项目(51275385)
【分类号】：TM311

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