摘要
空冷风机桥架振动的问题一直困扰着北方火电厂。振动幅值过大引起风机、电机与减速机等设备损坏,影响电厂运行的稳定性与经济效益。以山西孝义某电厂空冷风机桥架速度超标为对象,并使用数据采集仪器和加速度传感器对空冷风机桥架进行了振动测试。通过分析振动信号,并根据产生的频率特征来探索引起风机桥架振动的主要影响因素。测试结果发现,桥架振动过大是由于风机偏心质量引起的干扰力导致的。风机在工作运行过程中,桥架中部传感器位置处的相位正负交替,偏心质量使风机轴产生了摇摆,与桥架预期的水平振动并不一致。为了再次验证上述分析的合理性,对桥架进行有限元仿真分析,其分析结果与上述结论吻合。通过风机桥架的强迫振动实验和锤击实验发现,偏心质量引起桥架振动的最大频率值距离风机桥架的自振频率较远,不会引起风机桥架发生共振现象,所以,偏心质量引起的桥架振动仅与风机桥架的静刚度有关。测试结果将为梁式桥架设计和避免风机偏心引起的桥架振动提供依据。
The vibration problem of air-cooling fan bridge has been troubling the north thermal power plant.Excessive vibration amplitude causes the damage of fan,motor,reducer and other equipment,and affects the stability and economic benefit of power plant operation.In this paper,the vibration speed of the air-cooling fan exceeded the standard as the research object,and the data acquisition instrument and acceleration sensor were used to test the vibration of the air cooling fan bridge in the power plant of xiaoyi in Shanxi Province.According to the frequency characteristics generated by these incentives,the main influence factors of the vibration of the fan bridge caused by the original fan blades were explored.By analyzing the vibration signal,the main influencing factors of the vibration of fan bridge are explored according to the frequency characteristics.The test results show that the excessive vibration of the bridge is caused by the interference force caused by the fan eccentric mass.During the operation of the fan,the phase of the sensor at the middle of the bridge alternates positively and negatively,and the fan shaft produces a sway,which is inconsistent with the expected horizontal vibration of the bridge.In order to verify the rationality of the above analysis,the finite element analysis of the bridge frame was carried out,and the results are consistent with the above conclusions.Through the forced vibration test and hammer test of the fan bridge,it is found that the maximum frequency value of the vibration of the fan bridge caused by eccentric mass is far away from the natural vibration frequency of the fan bridge,and will not cause the resonance phenomenon of the fan bridge.Therefore,the vibration of the fan bridge caused by eccentric mass is only related to the static stiffness of the fan bridge.The test results will provide a basis for the design of beam bridge and the avoidance of vibration caused by fan eccentricity.
作者
郭铁能
孟令军
白春生
华旭
GUO TieNeng;MENG LingJun;BAI ChunSheng;HUA Xu(Beijing Key Laboratory of Advanced Manufacturing Technology,Beijing University of Technology,Beijing 100124,China;Insitute of Advanced Manufacturing and Intelligent Technology,Beijing University of Technology,Beijing 100124,China)
出处
《机械强度》
CAS
CSCD
北大核心
2021年第1期71-76,共6页
Journal of Mechanical Strength
基金
国家自然科学基金项目(51875009)
北京市自然科学基金项目(3162005)资助。
关键词
风机桥架
振动测试
偏心质量
振动频率
有限元分析
Fan bridge
Vibration test
Eccentric mass
Vibration frequency
Finite element analysis
