超超临界汽轮机转子的密封动力特性研究  

Study on Seal Dynamic Characteristics of Ultra-supercritical Steam Turbine Rotor

作　　者：焦晓峰[1] 李晓波[1] 贾斌[1] 司和勇 陈东超 JIAO Xiao-feng;LI Xiao-bo;JIA Bin;SI He-yong;CHEN Dong-chao(Inner Mongolia Power Research Institute,Hohhot 010020,China;School of Energy and Power Engineering,Northeast Electric Power University,Jilin 132012,China)

机构地区：[1]内蒙古电力科学研究院,呼和浩特010020 [2]东北电力大学能源与动力工程学院,吉林132012

出　　处：《汽轮机技术》2022年第6期439-444,共6页Turbine Technology

基　　金：内蒙古电力科学研究院自筹科技项目(2020-9)。

摘　　要：超超临界汽轮机组的蒸汽参数高、转子的直径大,可能使得密封结构的汽流激振问题更加突出。以某1000MW汽轮机超高压缸迷宫密封为例,建立三维密封转子模型,采用改进用户自定义函数(UDF)实现转子的多频涡动模拟。以机组热耗验收工况为边界参数,分析了不同负荷、压比、预旋比下密封动力特性的变化规律。结果表明:高频率下直接刚度受负荷影响明显。密封前后压差增大,蒸汽轴向贯通效应增强,周向旋转减弱,有效阻尼提升。变压比下密封的动力特性变化与变负荷相似。压比增加,有效阻尼增加,密封抑制涡动作用较好。密封动力特性会受到进口蒸汽速度预旋较明显的影响,涡动频率在10Hz以下或55Hz以上时,转子密封的稳定性比较差。The seal of ultra-supercritical steam turbine rotor has the characteristics of high steam parameters and large rotor diameter,so the problem of seal steam excited vibration is more obvious.Taking the labyrinth seal of a 1000MW steam turbine as an example,the three-dimensional seal rotor model is established,and the multi frequency whirl simulations of the rotor are realized by using the improved user-defined function(UDF)in fluent.Taking the heat consumption acceptance condition(THA)of the unit as the boundary parameters,the dynamic characteristics of the seal under different load,pressure ratio and pre rotation ratio are analyzed.The results show that the direct stiffness is obviously affected by the load at high frequency.With the increase of the pressure difference of inlet and outlet,the axial penetration effect of steam increases,the circumferential rotation weakens,and the effective damping increases.The variation of dynamic characteristics of the seal under variable pressure ratios is similar to that under variable loads.With the increasing of pressure ratio,the effective damping increases,and the seal has a good effect on suppressing rotor whirl.The inlet prerotation has a great influence on the dynamic characteristics of the seal,and the seal dynamics is poor when the frequency is below 10Hz or above 55Hz.

关 键 词：超超临界机组 迷宫密封 汽流激振 动力特性 

分 类 号：TM264[一般工业技术—材料科学与工程]