Experimental Study on Orbit of Shaft Centerline of Mixed-flow Pump during Starting Period
Experimental Study on Orbit of Shaft Centerline of Mixed-flow Pump during Starting Period
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DOI：
10.3901/jme.2016.22.168
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发表时间：
2016
影响因子：
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通讯作者：
Li Wei;Leilei Ji;Weidong Shi;Weiqiang Li;Zhou Ling;Xiaoping Jiang
中科院分区：
文献类型：
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作者：
Li Wei;Leilei Ji;Weidong Shi;Weiqiang Li;Zhou Ling;Xiaoping Jiang
混流泵启动过程中的振动不稳定严重威胁着水泵机组的安全，通过对轴心轨迹的研究，可以全面、直观地反映机组运行稳定性的暂态影响，掌握非正常运行状态下转子的振动状态。基于Bentley 408数据采集系统，获得了不同转速下起动过程中的转子轴心轨迹图和时间域图，提纯了1X和2X频率的转子轴心轨迹图和时间域图，并对不同转速下的频谱图进行了分析。研究结果表明，在起动过程中，1X频率的轴心轨迹图由长短轴相似的椭圆逐渐变为圆形，可以判断转子有弧形旋涡且涡量在增加；2X频率的轴心轨迹图从相似的水平线段逐渐变为水平扁平椭圆，可以判断转子有偏心现象，水平振动增大。连接暂态外特性曲线，研究发现，随着转速的逐渐提高，转子系统的瞬时水力载荷逐渐增大，转子的不平衡量和径向偏移量逐渐增大，振动情况逐渐加重，当转速达到最大值时，轴系振动出现峰值，随着转速趋于稳定，轴系振动逐渐减小并趋于稳定。加速度是轴系振动的主要原因，而瞬时效应是影响轴系振动劣化的重要因素。研究成果对实时评估混流泵启动过程中轴系运行状态，有效减少或防止振动恶化具有重要的工程应用价值和理论指导作用。
： The vibration instability during the startup process of mixed flow pump seriously threatens the safety of the pump unit,and through the research of the orbit of shaft centerline, it can comprehensively and visually reflect the transient effect on the stability of unit operation and hold the vibration state of rotor under abnormal operation condition . Based on the Bentley 408 data acquisition system, it obtained the rotor axis locus chart and time domain chart during starting process under different rotational speed, and purified its the rotor axis locus chart and time domain chart of the 1X and 2X frequency ,and analyzed the spectrum diagram under different rotating speed .The research results show that, during the startup process ,the orbit of shaft centerline chart of the 1X frequency is from a ellipse which long axis and short axis is similar gradually into a circle, and it can judge that the rotor has arcuate rotating vortex and the vortex is increasing; the orbit of shaft centerline chart of the 2X frequency is from similiar horizontal line segment gradually into a horizontal flat ellipse, and it can judge that the rotor has eccentric phenomena and the horizontal vibration is increasing. Connect to the transient external characteristic curve, the study found that as the speed increases gradually, and the rotor system transient hydraulic load increases gradually, and the rotor imbalance and radial offset increases gradually, and the vibration situation gradually aggravate, when the speed reach maximum, a peak is coming in shafting vibration and with the speed tends to stability it decreases and gradually becomes stabilized. Acceleration is the main cause of shafting vibration, and transient effects are the important factors influencing the deterioration of vibration. The research results for the real time assessment of shaft system operation state during the startup process of mixed flow pump, and for reducing or preventing the deterioration of vibration effectively has important value of engineering application and theory instruction function.