某核电站主给水前置泵振动超标治理

Treatment on excessive vibration of the main feedwater booster pump in a nuclear power plant

某核电项目主给水系统采用3台33.3%额定容量的定速泵泵组,调试期间所有主给水前置泵均存在驱动端轴承振动偏高且随着运行时间增加振动缓慢爬升的问题。为解决该问题,采取了重新找中、紧固出入口管道支吊架、调整管道平行度和同心度、调整轴瓦接触面等措施,但均不能有效降低振动。通过分析振动频谱图,结合主给水前置泵制造和安装特性,制定并实施了主给水前置泵轴承箱改造方案,大幅降低了振动值,有效解决了振动超标问题,同时改善了泵体和轴承箱刚度。

Three constant speed pumps with 33.3%rated capacity are used in the main water supply system of a nuclear power project.During the commissioning,drive shaft end bearings of all the main feedwater booster pumps were of excessive vibrations,which grew slowly with the increase of running time.To solve the problem,we took a series of measures,such as re-alignment of the coupling,fastening inlet and outlet pipe supports,readjusting the parallelism and concentricity of pipes and adjusting the bearing interfaces,but none of them can effectively alleviate the vibration.Through analysis on the vibration spectrum,as well as the manufacturing and installation features of the pumps,we have formulated and implemented a bearing box transformation scheme for the main feedwater booster pumps,which has greatly reduced the vibration value,effectively solved the problem of excessive vibration,and improved the stiffness of pump body and bearing case.