单支撑1000 MW超超临界汽轮机轴系不平衡响应分析

摘要

The finite element model to calculate the unbalance response of a 1000 MW ultra supercritical turbine with single bearing support was set up.The unbalance response during run up process was calculated and analyzed.The response difference between single-bearing support unit and double-bearing support unit was compared.It is pointed out that single support bearings at two sides of the rotor can be treated as double supports of the rotor.The unbalance plane and unbalance mode can be analyzed from the vibration of these bearings.The vibration coupling between rotors is significant,especially at rotor resonance zone.If operation speed is far away from critical speeds,the coupling effect is not distinct.The phase lag between the unbalance couple and vibration at operation speed is usually larger than 120 degree though the 2nd critical speed is far less than the operation speed.A high speed dynamic balance test was done for the 1000 MW unit in field.The calculated results were verified.%建立单支撑1000 MW超超临界汽轮机不平衡响应分析有限元模型，计算升速过程中轴系不平衡响应特性，比较单、双支撑机组不平衡响应差别。研究结果表明，不平衡响应分析时可将转子两侧单支撑轴承视为该转子的双支撑，由此两轴承振动分析不平衡面及不平衡型式。单支撑汽轮机转子之间振动耦联性较强，突显于相邻转子两临界转速附近。工作转速远离临界转速时相互间影响并不大。虽转子二阶临界转速远高于工作转速，但采用单支撑模式机组转子不平衡力偶与振动间相位滞后角大多在120°以上。通过对1000 MW汽轮机组进行低压转子现场高速动平衡试验，不平衡响应分析结果获得试验验证。