汽轮机转子有限元应力计算中网格划分的研究

Research on Grid Division in Finite Element Stress Calculation of Steam Turbine Rotor

由于升级改造后的汽轮机机组的蒸汽温度和压力都将明显提高,使得对汽轮机转子的应力计算精度要求也随之提高。在实际应用中,某些关键部位的应力情况对转子整体强度起着决定性作用,但有限元应力计算中,关于这些关键部位的局部网格划分方法的讨论不充分,为了在得到精确的计算分析结果的同时,又不影响计算效率,选择合理的局部区域和网格尺寸很关键。以计算某型号亚临界汽轮机高压转子在稳态额定负荷工况下的应力分布情况为例,应用Ansys Workbench软件按不同的网格划分方式进行有限元计算,得出该型号汽轮机高压转子应力集中的危险部位的应力值结果,进行比较分析。总结出一套适合汽轮机机组升温改造项目的有限元应力计算方法。

Due to the significant increase in steam temperature and pressure of the upgraded steam turbine unit,the requirements for stress calculation accuracy of the steam turbine rotor will also be improved.In practical applications,the stress situation of some key parts plays a decisive role in the overall strength of the rotor.However,in finite element stress calculation,the discussion of local mesh generation methods for these key parts is insufficient.In order to obtain accurate calculation and analysis results without affecting computational efficiency,it is crucial to select a reasonable local area and mesh size.Taking the calculation of the stress distribution of the high-pressure rotor of a certain type of subcritical steam turbine under steady-state rated load conditions as an example,the ANSYS Workbench software was used to conduct finite element calculations according to different grid division methods,obtaining the stress value results of the dangerous parts of the high-pressure rotor of this type of steam turbine with stress concentration,and performing comparative analysis.Summarize a set of finite element stress calculation methods suitable for steam turbine unit raising temperature projects.