基于导热正反问题耦合解法的增压锅炉汽包应力有限元分析

Finite element stress analysis for turbo-charged boiler drums based on direct and inverse heat conduction coupling method

为快速得到精确的增压锅炉汽包的应力分布,针对其外壁局部受热的特点,提出了基于导热正反问题耦合解法的汽包瞬态应力求解方法,即采用导热正反问题耦合解法求解复杂边界条件下的增压锅炉汽包温度场,在此基础上,采用二维有限元方法对汽包瞬态理论应力进行计算。同时,利用ANSYS软件对汽包三维温度场与应力场进行了模拟,并结合实验数据与本文方法计算结果进行了对比。结果表明:基于导热正反问题耦合解法求解的温度场具有较高的精度;本文方法计算的汽包理论应力与ANSYS软件模拟结果吻合较好,汽包壁上机械应力与热应力的应力集中系数分别比美国ASME标准推荐值高24.42%,5.32%。

To obtain the accurate stress distribution of turbo-charged boiler drums quickly,a method solving transient stress of the drums based on direct and reverse heat conducting coupling method was proposed,according to the local heating characteristics of the drum＇s outer surface.This method solves temperature field inside the turbo-charged boiler drum under complicate boundary conditions by using the direct and reverse heat conducting coupling method.On this basis,the drum＇s transient theory stress was calculated by the 2-D finite element method.Moreover,the 3-D transient temperature field and stress distribution of the drum were calculated by ANSYS software,and the results were compared with the experimental data.The results show that,the coupling method of direct and inverse heat conduction problem has high precision,and the drum＇s theory stress obtained by above method agrees well with that by the ANSYS software,the stress concentration factors of the mechanical stress and thermal stress on the drum wall are respectively24.42% and 5.32%larger than the ASME standard recommended values.