转子磁通量超标对振动的干扰影响研究

针对某炼油项目中蜡油加氢汽轮机在单机试车过程中驱动端轴振动超标、停机检查时发现静态电跳量过大等问题,对该机组单机试运行时的振动频谱图和轴心轨迹图进行了判断分析,并采用大头针吸附方式对该转子进行了磁性检查,确认转子被磁化。然后通过磁感效应理论分析,进一步对电涡流传感器的工作原理、磁通量对电涡流传感器的信号干扰以及电涡流传感器与被测金属体有无磁性的关系等进行了分析研究,并建立了实验模型,模拟实验和结合实际工程应用进行论证。研究结果表明,当汽轮机转子磁通量超过API Std 612低于3高斯的标准要求时,磁通量会对该点的径向振动产生较大的信号干扰影响,采取消磁滚压再消磁的对策措施,可解决这个难题,并对类似问题具有参考意义。

Vibration interference influence by the excessive magnetic flux of rotor

Aiming at the vibration on the drive shaft side of wax oil hydrogenation turbine was too large to run normally when the steam turbine was in commissioning process in a refinery project and the shaft electrical run-out was also too large.The vibration spectrum and axis orbit of the turbine shaft were analyzed,and the shaft magnetism was test by using pin to approach rotor slowly,the pin was attracted,it was indicate that the rotor was magnetized.The principle of eddy current sensor,the eddy current sensor signal were influenced by the magnetic flux,and the relationship between eddy current sensor and the measured metal body were further investigated by magnetoresistance effect theory,then the experimental model was established and simulated,and combined with engineering applications.The result indicates that the magnetic flux of rotor is over ANSI/API Std 612 standers and the vibration interference is influenced by the excessive magnetic flux of rotor through theory analysis and experiment test.Then adopting degaussing and rolling countermeasures and solving this problem,it is reference for other similar problems.