中比转速离心泵进口回流特性研究

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振动与冲击 ›› 2020, Vol. 39 ›› Issue (22) : 8-15.

论文

中比转速离心泵进口回流特性研究

袁建平1，王振清1，付燕霞2，侯敬生1

作者信息 +

Experiments on the backflow characteristics at the inlet of a moderate-speed centrifugal pump

YUAN Jianping1，WANG Zhenqing1，FU Yanxia2，HOU Jingsheng1

Author information +

文章历史 +

摘要

离心泵运行在小流量工况下时，进口会出现回流现象，回流的发生会恶化叶轮进口的流动，降低泵的性能，影响泵的运行可靠性。为研究离心泵小流量工况下进口回流特性，以IS100-80-160型离心泵为对象，采用CFD软件ANSYS CFX，基于RNG k-ɛ湍流模型对模型泵内部流场进行了定常、非定常数值模拟，获取1.0QBEPA 、0.85QBEPA 、0.51QBEPA、0.34QBEPA工况点下叶轮进口流动状态、进口管内速度分布、湍流分布及进口各截面压力分布，并对叶轮进口处及进口管内压力脉动信号进行频域分析得到以下结论：回流出现时，叶轮进口的流动状态可以分为螺旋状回流、螺旋状入流和轴向入流；回流发生时具有明显的低频高幅脉动特征；螺旋状回流的流动相比于轴线区域的轴向入流更加不稳定。搭建了闭式试验台，对模型泵进行了外特性试验与压力脉动实验，采集了压力脉动信号，并针对主要频域进行相位分析，验证了数值模拟结果的正确性。本研究为小流量回流工况下离心泵进口不稳定流动预测提供依据，丰富了离心泵设计理论，对并为水力优化提供一定的参考。

Abstract

When a centrifugal pump operates in small flow condition, the backflow will occur at the inlet, which will deteriorate the flow at the impeller inlet, reduce the performance of the pump and affect the operation reliability of the pump.In order to investigate the back-flow characteristics of the moderate-speed centrifugal pump, the back-flow in the centrifugal pump typed IS100-80-160 was numerically simulated based on the RNG k-ε turbulent model by using the CFD software ANSYS CFX.The flow state at the impeller inlet, and the velocity, turbulent and pressure distribution in the inlet pipe in the working states of 1.0QBEPA, 0.85QBEPA, 0.51QBEPA and 0.34QBEPA were investigated and the pressure fluctuation characteristics were analyzed in frequency domain.The results show that when the flow rate is reduced, some of the fluid particles collide with the solid wall under the action of centrifugal force, causing the velocity and pressure change in the region and the formation of back-flow.It is found that the characteristics of pressure fluctuation have the features of low frequency and high amplitude, and the spiral back-flow is more unsteady than the axial back-flow.A closed type test rig was set up to investigate the hydraulic performances of the model centrifugal pump, the pressure pulsation test was carried out, and the phase correlation analysis was performed on the pressure fluctuation signal at the detection point, which proves that the numerical model can accurately describe the characteristics of back-flow at the pump inlet.The study provides a basis for predicting the back-flow at the inlet of the centrifugal pump under the condition of small flow, enriches the design theory of centrifugal pumps, and provides a reference to hydraulic optimization.

导出引用

袁建平1，王振清1，付燕霞2，侯敬生1. 中比转速离心泵进口回流特性研究[J]. 振动与冲击, 2020, 39(22): 8-15

YUAN Jianping1，WANG Zhenqing1，FU Yanxia2，HOU Jingsheng1. Experiments on the backflow characteristics at the inlet of a moderate-speed centrifugal pump[J]. Journal of Vibration and Shock, 2020, 39(22): 8-15

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