Analysis of the Pressure Pulsation and Vibration in a Low-Specific-Speed Centrifugal Pump
Analysis of the Pressure Pulsation and Vibration in a Low-Specific-Speed Centrifugal Pump
复制标题
低比转数离心泵压力脉动与振动分析
DOI：
10.1115/1.4048691
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发表时间：
2021-02-01
影响因子：
2
通讯作者：
Huang, Yakun
中科院分区：
文献类型：
--
作者：
Cui, Baoling;Zhang, Yingbin;Huang, Yakun
离心泵内部流动不稳定引起的非定常压力脉动和流体力是引起离心泵振动的重要原因，不利于泵的安全运行。本文采用分离涡模拟方法，对低比转速离心泵内的压力脉动和径向力进行了数值模拟。并对离心泵轴进行了振动位移实验。为了阐明非定常流场结构与压力脉动之间的内在联系，引入了涡识别方法。结果表明，叶轮出口压力脉动与叶片压力面周期性涡脱落密切相关。在小流量时，较大的尾涡芯与蜗壳舌之间的动静相互作用会在泵内产生较大的压力脉动和径向力。在大流量下，尾涡核容易破碎和分散，导致压力脉动和径向力比小流量时小。在设计流量下，叶轮内压力脉动强度和径向力均小于非设计流量下。叶轮径向力与轴径向位移的谱图在轴频处均呈现较高的幅值。泵轴的振动与叶轮上的径向力密切相关。
Unsteady pressure pulsation and fluid force induced by flow instabilities in the centrifugal pump is an important cause of vibration, which is detrimental to the safe operation of the pump. In this study, we numerically investigated the pressure pulsation and radial force in a low-specific-speed centrifugal pump by using the detached-eddy simulation method. We also performed a vibration displacement experiment on the shaft of the centrifugal pump. The vortex identification method was introduced to clarify the internal correlation between unsteady flow structures with pressure pulsations. The results showed that the pressure pulsations at the impeller outlet were closely associated with the periodic vortex shedding from the blade pressure surface. The rotor–stator interaction between a relatively big trailing vortex core and volute tongue generated larger pressure pulsation and radial force in the pump at a low flow rate. Under a large flow rate, the trailing vortex core was easily broken and dispersed, and this resulted in smaller pressure pulsation and radial force compared with that at a low flow rate. Under the design flow rate, the pressure pulsation intensity and the radial force in the impeller were smaller than that under the off-design flow rate. Compared with the spectra between the radial force on the impeller and radial displacement on the shaft, they both presented higher amplitude at the shaft frequency. The vibration of the pump shaft was closely related to the radial force on the impeller.