基于有限元技术的大型汽轮机转子寿命评估系统

A Rotor Service-life Evaluation System for Large-sized Steam Turbines Based on Finite Element Technology

结合机械结构寿命评价理论和数值分析方法,对基于有限元的大型汽轮机转子寿命评估系统进行研究。采用归一化方法对复杂的转子实际换热边界条件进行处理;依据转子的运行历史数据和结构几何参数自动生成传热学、力学边界条件,利用Delaunay非结构化自动剖分算法对几何模型进行网格剖分,将载荷谱处理和损伤累积无缝嵌入有限元分析过程。在此基础上,形成了基于复杂数值方法的转子寿命评价集成化系统,该系统具备了转子稳态、瞬态温度场、应力场和应变场分析及损伤和寿命评估功能,能直观显示转子损伤场分布及其演变,克服了传统方法中一些难以处理的技术障碍。

In combination with service-life evaluation theories and numerical analysis methods for mechanical structures, a study has been conducted of a finite-element-based service-life evaluation system for rotors of large-sized steam turbines. A normalized method was adopted to process the boundary conditions of complicated actual heat exchange in rotors. The boundary conditions of heat transfer and mechanics theory have been automatically generated based on the historical operating data and structural geometric parameters. A mesh dissection was conducted of a geometric model by using a Delaunay non-structural automatic dissection algorithm. The load spectrum treatment and damage build-up were seamlessly inserted into a finite-element analysis process. On this basis, formed was an integrated system of rotor service-life evaluation based on a complicated numerical method. The above system can provide such functions as the analysis of rotor steady-state and transient temperature, stress and strain fields as well as the evaluation of rotor damage and service life, thus visually displaying the distribution of rotor damage fields and their evolution, and at the same time overcoming some technically intractable hindrances specific to traditional methods.