Abstract:

To improve the cavitations performance of centrifugal pumps, using the combination of CFD numerical simulation and experimental study on the long blade and short blade centrifugal pump and vapor-liquid two-phase rules inside the impeller were analyzed in different NPSH, and the effect  of three different short blades in different cavitations conditions  on the impeller internal flow and performance was analysed. It is concluded:the selection of reasonable import diameter can improve the performance of anti-cavitation, while the NPSH fell to some degree, and centrifugal pump import diameter is 0.65D2, whirlpool cavitation zone appears on the back of long blade and short blade;while centrifugal pump import diameter is 0.75D2, there are two whirlpool cavitation zones on the back of long blade and short blade;it has worked best with anti-cavitation performance that the centrifugal pump import diameter is 0.85D2.

Key words: centrifugal pump, long and short blades;cavitation;numerical simulation, experiment

摘要：

为提高离心泵的汽蚀性能，利用CFD数值模拟分析与实验研究相结合的方法对长短叶片离心泵在不同汽蚀余量时叶轮内部气液两相的分布规律进行分析研究，分析了3种不同短叶片进口直径在不同汽蚀工况时气泡分布情况对叶轮内部流动和性能的影响。分析结果表明：选择合理短叶片的进口直径可以有效提高离心泵的抗汽蚀性能，避免叶轮进口堵塞和流道内发生漩涡汽蚀。当汽蚀余量减小到一定程度，离心泵短叶片进口直径为0.65D2(D2为叶轮外径）时，在长叶片和短叶片的背面都会出现漩涡汽蚀区;当离心泵短叶片进口直径为0.75D2时，在长叶片背面与短叶片工作面间的流道内会出现两个漩涡汽蚀区;当离心泵短叶片进口直径为0.85D2时,离心泵的抗汽蚀性能最佳。
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关键词: 离心泵, 长短叶片, 汽蚀, 数值模拟, 实验