Effects of an Inlet Vortex on the Performance of an Axial-Flow Pump
Effects of an Inlet Vortex on the Performance of an Axial-Flow Pump
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DOI：
10.3390/en13112854
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发表时间：
2020-06
期刊：
影响因子：
3.2
通讯作者：
Wenpeng Zhang;F. Tang;Lijian Shi;Hu Qiujin-;Ying Zhou
中科院分区：
文献类型：
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作者：
Wenpeng Zhang;F. Tang;Lijian Shi;Hu Qiujin-;Ying Zhou
进口涡流的形成严重制约了轴流泵装置的性能，对整个系统的安全稳定运行构成了极大的威胁。本文在立式轴流泵装置上，对进口涡的变化趋势及其对轴流泵的影响进行了数值模拟和实验研究。在叶轮前安装了四组固定式涡流发生器（VG），以在叶轮进口处产生稳定的涡流。定性和定量地分析了旋涡对泵装置性能的影响。通过对泵装置内不同位置、不同时刻的旋涡形态的研究，揭示了叶轮内旋涡形态的变化趋势以及由旋涡引起的压力脉动。外特性和压力脉动实验结果验证了定常和非定常数值计算结果的可靠性和准确性。结果表明，在叶轮进口前安装涡流发生器以产生稳定的涡流是可行的。涡对叶轮进口流场产生扰动，导致轴向速度加权平均角和轴向速度均匀性显著降低。涡流增加了进口流道的水力损失，降低了叶轮效率，但对导叶和出口流道的性能影响不大。涡流引起低频压力脉动并与叶轮相互作用。旋涡离叶轮进口越近，叶轮对旋涡的影响越显著。叶片切断了叶轮中的旋涡，以后旋涡随叶片旋转而减弱。
The formation of an inlet vortex seriously restricts axial-flow pump device performance and poses a great threat to the safe and stable operation of the entire system. In this study, the change trends of an inlet vortex and its influence on an axial-flow pump are investigated numerically and experimentally in a vertical axial-flow pump device. Four groups of fixed vortex generators (VGs) are installed in front of the impeller to create stable vortices at the impeller inlet. The vortex influence on the performance of pump device is qualitatively and quantitatively analyzed. The vortex patterns at different positions and moments in the pump device are explored to reveal the vortex shape change trend in the impeller and the pressure fluctuation induced by the vortex. The reliability and accuracy of steady and unsteady numerical results are verified by external characteristics and pressure fluctuation experimental results. Results show that it is feasible to install VGs before the impeller inlet to generate stable vortices. The vortex disturbs the inlet flow fields of the impeller, resulting in significant reductions of the axial velocity weighted average angle and the axial velocity uniformity. The vortex increases the inlet passage hydraulic loss and reduces the impeller efficiency, while it only slightly affects the guide vane and outlet passage performance. The vortex causes a low-frequency pressure pulsation and interacts with the impeller. The closer the vortex is to the impeller inlet, the more significant the impeller influence on the vortex. The blade cuts off the vortex in the impeller; afterwards, the vortex follows the blade rotation, and its strength weakens.