流量对多相混输泵首级动叶轮气相分布的影响

Effect of Flow Rate on Gas Distribution on the First-Stage Impeller of Multiphase Pump

气液两相分布规律是研究多相混输泵性能的重要内容,同时也与其优化设计密切相关。为了进一步揭示变流量工况下多相混输泵内气液两相分布规律,首先利用三维造型软件对混输泵全流道计算域进行建模,其次基于时均N-S方程和k-ε湍流模型,采用CFD技术在进口含气体积分数为30%时对泵内气液两相三维流态进行模拟,最后分析和总结了流量对混输泵叶轮压力面和吸力面不同叶高气相分布的影响规律。分析结果表明:在不同流量下,气相在首级动叶轮不同叶高进口附近变化均比较剧烈,并且流量对叶片后半段气体体积分布规律影响较大,特别是对吸力面上的影响最大;气相在首级动叶轮0.1倍叶高处压力面和吸力面从进口到出口的变化趋势相反,而在其他叶高处的变化趋势均相似;在不同流量下首级动叶轮叶片出口位置气相分布均出现了不同程度的波动。研究结果可为提高多相混输泵气液输送能力提供参考。

The gas-liquid two-phase distribution law is an important content of studying the performance of multiphase pumps,and it is also closely related to its optimal design.In order to further reveal the gas-liquid twophase distribution law in the multiphase pump under variable flow conditions,three-dimensional modeling software is used to model the full-channel calculation domain of the multiphase pump.Then,based on the time-averaged NS equation and k-εturbulence model,the CFD technology is used to simulate the gas-liquid two-phase three-dimensional flow pattern in the pump when the gas volume friction at the inlet is 30%.Finally,the influences of the flow rate on the pressure surface and suction surface of the multiphase pump impeller at different heights are analyzed and summarized.The analysis results show that,at different flow rates,the gas phase changes drastically near the inlets of the first-stage impeller blade at different heights,and the flow rate has a great impact on the gas volume distribution at the second half of the blade,especially above the suction surface.At different flow rates,the gas phase distribution at the outlet of the first-stage impeller blade fluctuates in varying degrees.The research results provide a reference for improving the gas-liquid transport capacity of the multiphase pump.