某40 MW汽轮机组末级长扭叶片枞树型叶根设计  

Design of Fir-tree Blade Root of the Last Long Twisted Blade of a 40 MW Steam Turbine

作　　者：王超军 Wang Chaojun(Steam Turbine Research Institute,Guangzhou Guangzhong Enterprise Group Corporation,Guangzhou 511495,China)

机构地区：[1]广州广重企业集团有限公司汽轮机研究所,广州511495

出　　处：《机电工程技术》2024年第7期279-282,共4页Mechanical & Electrical Engineering Technology

摘　　要：介绍了某40 MW汽轮机组末级长扭叶片的两种枞树型叶根结构,比较了两种叶根结构采用传统算法时的应力情况,评估了枞树型叶根优化的可行性,并建立了长扭叶片的有限元分析模型。通过对长扭叶片与轮槽进行有限元计算,分析了汽轮机末级长扭叶片枞树型叶根过渡段轴向长度及轮缘处叶根轴向斜角在不同取值时叶根的最大等效应力,确定了枞树型叶根的几何参数,同时为保证叶片和机组的安全可靠性,建立了长扭叶片的模态分析模型,分别计算了叶片在4 900 r/min和5 000 r/min时的前3阶的固有频率,确定其动频振动特性,避免共振的发生,最终达到了优化汽轮机组末级长扭叶片枞树型叶根结构的目的。同时建立的长扭叶片有限元分析模型为今后同类叶片设计问题提供了理论支持和解决方案。Two kinds of fir-tree blade root structures of the last stage blade of a 40 MW steam turbine are introduced,the stress of the two kinds of blade root structures when using the traditional algorithm are compared,the feasibility of optimizing the fir-tree blade root is evaluated,and the finite element analysis model of the blade is established.Based on the finite element calculation,the axial length of the transition section of the fir-tree blade root of the last stage of the steam turbine and the maximum equivalent stress of the blade root at different values of the axial oblique angle of the blade root at the rim are analyzed,and the geometric parameters of the fir-tree blade root are determined.At the same time,in order to ensure the safety and reliability of the blade and the unit,the modal analysis model of the long twisted blade is established,and the natural frequencies of the first three steps of the blade at 4 900 r/min and 5 000 r/min are calculated respectively,and its dynamic frequency vibration characteristics are determined.At the same time,the finite element analysis model of long twisted blades provides theoretical support and solutions for similar blade design problems in the future.

关 键 词：汽轮机 枞树型叶根 有限元 应力 振动 

分 类 号：TK263[动力工程及工程热物理—动力机械及工程]