LIAO Wei bing1, LIU Bai lan2,3, YU Pei jiong2,3, DING Xu dong3,4

 

(1. Department of International Trading, Hangzhou Steam Turbine Co., Ltd., Hangzhou 310022, China;

 

2. Industrial Turbine Academy Turbomechanical Institute, Hangzhou Steam Turbine Co.,Ltd., Hangzhou 310022, 

 

China; 3. Key Laboratory of Zhejiang Industrial Steam Turbine Rotor Dynamics, Hangzhou 310022, China;

 

4. Central Institute,Hangzhou Steam Turbine & Power Group Co.,Ltd., Hangzhou 310022, China)

 

 

Abstract: Aiming at keeping rotor dynamics stability during industrial steam turbine operation, an analysis method and analysis steps were introduced to analysis a steam turbine rotor with overhung which was designed by Hangzhou Steam Turbine Corporation. The mathematic model of rotor synchronous orbit was analysed and the reasons for rotor instability were indicated. The maximum oil film temperature difference and rotor thermal bending unbalance were analysed, and the thermal bending unbalance was compared with an unbalance threshold which was calculated to check safety. A method to check steam turbine stability safety was introduced. The results demonstrate the thermal bending unbalance of the steam turbine rotor is less than the unbalance threshold and the turbine would keep stable in its operation speed range with no instability occuring.

 

Key words: steam turbine; rotor stability; bearing thermal stability