1000MW核电汽轮机低压内缸3D建模与轴封变形分析

3D Modeling and Gland Seal Deformation for the Low Pressure Inner Casting of a 1000MW Nuclear Steam Turbine

对某1 000 MW核电汽轮机低压内缸进行了三维建模,并进行有限元分析,计算了稳定运行工况下,负荷、上下缸温差以及抽真空过程对轴封变形的影响。计算结果表明：在温度、压力的综合作用下,并受汽缸变形影响,轴封变形膨胀,向内倾斜。其中低压内缸内外压差是造成轴封向内倾斜的主要原因,同时上下缸温差也是造成轴封内倾的原因之一。汽缸受热膨胀会减轻轴封的向内倾斜程度。

In this paper, the 3 D modeling of LP inner casing for a 1 000 MW nuclear steam turbine has been established,and the finite element analysis has been carried out using ANSYS WORKBENCH soft- ware. We have calculated and analyzed the influence of load, temperature difference between upper and lower casing and vacuum pumping process on the deformation of gland seal under the stable operating conditions. The results show that the gland seal expands and tilts inwards due to the combined action of temperature and pressure, and the deformation of the casing. The pressure difference between inside and outside of the casing is the main cause for the gland seal tilt, while the temperature difference between upper and lower casing is also one of the reasons. The expansion of the casing can reduce the inclination of the gland seal.