某40MW汽轮机组末级长扭叶片枞树型叶根设计OA

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.