【摘要】 计算分析了３００ＭＷ汽轮机低压缸末级长叶片Ａ_０振型弯曲振动与轴系扭振耦合对叶片安全性的影响。末级长叶片与轴系扭振耦合将使该叶片振动的实际频率避开率低于计算值，当发生严重的两相短路故障时在叶片根部的最大动弯矩远远高出其额定值；如果电网频率偏离５０Ｈｚ，会对叶片安全性产生更为不利的影响。更多还原

【Abstract】 The coupling of the flexural vibration of the long blades at the final stage of the low Pressure turbine with the shaft torsional vibrations, principally occurs in response to the negative sequence excitation effects derived from either an electrical system unbalance or unsymmetrical disturbance conditions. The effect of the coupling vibration on the blade security is evaluated based on a 300MW turbogenerator. The practical frequency avoidance ratio of the blades is lower than the calculated value and the transient flexural torque at the blade roots by far higher than the rated in the case of the severe line to line fault. The worse case occurs when the electric -network frequency departures from the rated 50 Hz.更多还原