近零出力下汽轮机末级叶片颤振研究  

Study on Blade Flutter in the Last Stage of Steam Turbine Under Near Zero Output

作　　者：朱秋良 韩旭[1] 韩中合[1] ZHU Qiuliang;HAN Xu;HAN Zhonghe(Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学,河北省低碳高效发电技术重点实验室,保定071003

出　　处：《工程热物理学报》2025年第2期410-416,共7页Journal of Engineering Thermophysics

基　　金：河北省在读研究生创新能力培养资助项目(No.CXZZSS2023194);国家自然科学基金资助项目(No.52106042);中央高校基本科研业务费专项资金项目(No.2022MS084)。

摘　　要：低压缸零出力改造可以充分挖掘机组调峰能力,然而低压转子和内部工质摩擦会产生鼓风损失,末级流场极不稳定。基于国内外研究现状,以某300 MW汽轮机末级叶栅为研究对象,数值计算得到了不同流量工况下汽轮机末级叶片振动特性规律。结果表明:近零出力工况在20%THA处,随后末级进入鼓风工况,叶片升温速率加快;叶片的形变分布情况不随着流量的减小而发生较大的变化,动叶形变较大的区域位于叶片顶部出汽边缘处;随着流量的减小,由于叶片表面热应力增大的幅度大于压应力减小的幅度,导致动叶形变量随流量的减小而增大;近零出力工况下,动叶振动频率始终大于其共振频率,因此其不会发生共振。研究结果可为汽轮机零出力改造蒸汽流量设计提供参考。The zero output transformation of the low-pressure cylinder can fully tap the peak shaving capacity of the unit.However,the friction between the low-pressure rotor and the internal working medium will cause blowing loss and the last stage flow field is extremely unstable.Based on the research status at home and abroad,the vibration characteristics of the last stage blades of a 300 MW steam turbine under different flow conditions are obtained by numerical calculation.The results show that the near zero output condition is at 20%THA,and then the last stage enters the blowing condition,and the temperature rise rate of the blade is accelerated;the deformation distribution of the blade does not change greatly with the decrease of the flow,and the area where the deformation of the rotor blade changes greatly is located at the outlet edge of the blade top;with the decrease of flow rate,the increase of the thermal stress on the blade surface is larger than the decrease of the compressive stress,which leads to the increase of the blade deformation with the decrease of flow rate;under the condition of near zero output,the vibration frequency of the moving blade is always greater than its resonance frequency,so it will not resonate.The research results can provide a reference for steam flow design of zero output steam turbine.

关 键 词：汽轮机 近零出力工况 热应力 叶片颤振 

分 类 号：TK26[动力工程及工程热物理—动力机械及工程]