基于某超超临界汽轮机的中压进汽导流环结构，采用有限元分析方法对不同撑筋结构、不同撑筋数量、不同结构约束的进汽导流环方案进行了强度计算和模态分析。强度计算结果表明，各方案的稳态应力均较低，但增强撑筋的结构能够显著改善导流环的高温蠕变性能。模态计算结果表明，撑筋越强壮、数量越多，进汽导流环的各阶固有频率越高。但在其边界约束相同的情况下，各方案的低阶固有频率的差别不大。最终通过合理设定进汽导流环的外部约束显著提高其低阶固有频率，使其大范围避开汽轮机的工作频率。

Based on the IP inlet flow guide structure of an ultrasupercritical turbine,the strength calculation and modal analysis on several structure cases,including different support structures,support quantities and structure constraints,were carried out by using the finite element analysis method.The strength calculation results indicated that the steady state stress of each case is low,but the structure of reinforcing the supports can significantly improve the high temperature creep performance of the inlet flow guide.The modal calculation results showed that the stronger support or the greater number,the higher the natural frequency of each order.However,the difference of loworder natural frequency of each case was not noticeable under the same boundary constraints.Finally,the external constraint of the inlet flow ring was reasonably set to significantly increase its loworder natural frequency,avoiding the operating frequency of the turbine in a large area.

TK262

上海市科委发电过程智能管控工程技术研究中心基金资助项目（14DZ2251100）；上海市“科技创新行动计划”地方院校能力建设专项项目（19020500700）