摘要
针对某汽轮发电机组在电厂现场运行中存在低压缸瓦振超标,带负荷过程中瓦振波动较大的现象,采用模态分析技术对轴承座进行动力学特性诊断分析和动力修改。试验获得了轴承座的动刚度、模态振型、频率。通过试验确认轴承座的固有频率在运行频率范围内避开率低,动刚度偏低是引起轴承瓦振偏大的主要原因。采用有限元数值模型,对轴承座进行了动力学修改,确定了轴承座结构改进的方案。最后通过轴承座动刚度试验,验证了改进方案的有效性。轴承座改造后机组实际运行中振动特性得到明显改善。
The low pressure bearing vibration of the steam turbine plant often exceeds the standard level with vibration fluctuation phenomenon in the on-load process .Modal analysis technology is used to analyze the dynamic characteristics of the bearing seat and make dynamic modification .Experiments were conducted to obtain the mode shapes , the nature frequency and dynamic stiffness of the bearing seat .It is confirmed that the avoiding rate between the natural frequency of the bearing seat and the operating frequency is small .The dynamic stiffness is too low to cause the excessive bearing vibration.The finite element numerical model is used to make dynamic modification of the bearing seat and determine the structure optimization design .Finally, the bearing dynamic stiffness is tested to verify the effectiveness of the improved scheme.The vibration characteristics of the bearing seat of the unit is obviously improved .
出处
《汽轮机技术》
北大核心
2015年第1期40-42,共3页
Turbine Technology
关键词
模态分析
动力学修改
轴承座
瓦振
modal analysis
dynamic modification
bearing seat
bearing vibration
