汽轮机裂纹转子升速过程非线性振动数字仿真及分析  

Nonlinear vibration of steam turbine's crack rotor during speed-up process:digital simulation and analysis

作　　者：何青[1] 彭慧春[1,2] 翟鹏程[1] 甄亚欣[2] 

机构地区：[1]华北电力大学能源动力与机械工程学院,北京102206 [2]华北电力大学数理学院,北京102206

出　　处：《热力发电》2016年第11期5-12,24,共9页Thermal Power Generation

基　　金：国家自然科学基金项目(11402087)

摘　　要：基于应力强度因子为零法,建立了汽轮机转子升速过程中开裂纹转子和呼吸型裂纹转子的振动模型,并采用Runge-Kutta法对模型进行数值积分,实现升速过程中2种转子的稳态响应数字仿真及稳定性量化分析。结果表明:开裂纹转子和呼吸型裂纹转子在升速过程中均存在明显的1/3阶和1/2阶超谐共振;在超临界转速区,开裂纹转子和呼吸型裂纹转子均在转速比p=ω/ω0=2.10、2.20、2.55处出现了亚谐共振,该现象可作为判断转子裂纹故障是否存在的依据;在不同转速区,呼吸型裂纹转子与开裂纹转子的表现各不相同,尤其在超临界转速区,质量偏心e进一步抵消裂纹引起的非线性失稳,呼吸型裂纹转子出现局部渐进稳定区域,特别是在0.8<e<1.6时,质量偏心会进一步抑制非线性失稳运动,这一现象可为裂纹转子非线性运动失稳控制提供理论依据。By using the ＂stress intensity factor be zero＂ method, the vibration models for both open crack and breathing crack rotor during the turbine rotor speeding up process were established. The Runge-Kutta method was applied to carry out numerical integration for the models, to realize steady state response numerical simulation and stability quantitative analysis for the two types of rotor during speeding up process. The results show that,obvious 1/3 and 1/2 order superharmonic resonance phenomenon occurs on both the open crack rotor and breathing crack rotor in the process of speed up. In the supercritical speed zone,a subharmonic resonance phenomenon appears on both the open crack rotor and breathing crack rotor with the rotating speed ratio of 2. 1,2. 2 and 2. 55. This phenomenon can be considered as the basis for judging whether the rotor crack fault exists. In different rotating speed areas, the open crack rotor behaves differently from the breathing crack rotor,especially in the supercritical speed zone, the mass eccentricity e further counterpoises the nonlinear instability caused by the crack,a local asymptotic stability region appears on the breathing crack rotor, especially when the mass eccentricity e are higher than 0.8 but lower than 1.6,the mass eccentricity will enhance the nonlinear instability. This phenomenon can provide theoretical basis for control of nonlinear motion instability of crack rotors.

关 键 词：非线性振动 裂纹转子系统 汽轮机 升速过程 转子动力学 非自治系统稳定度 质量偏心 

分 类 号：O322[理学—一般力学与力学基础] O321[理学—力学]