基于改进欧拉算法的双吸离心泵泥沙磨损特性研究

发布时间：2018-05-24 00:46

本文选题：双吸离心泵 + 泥沙磨损　；参考：《农业机械学报》2017年03期

【摘要】：固液两相流算法对双吸离心泵泥沙磨损模拟精度有直接影响。采用改进的固液两相流欧拉算法,考虑了相间阻力和泥沙扩散系数两方面因素,对典型悬移质泥沙粒径条件下的双吸离心泵流场进行了数值计算。研究发现,叶片表面湍流强度在头部和尾部较大,可达6%~10%;叶片头部和尾部的颗粒动态尺度大于中部。由湍流强度和颗粒动态尺度组成的湍动尺度效应,在叶片头部和尾部表现强烈,湍动尺度效应使固液相间阻力增大,更有利于颗粒的扩散,避免了颗粒聚集,对大颗粒的作用强于小颗粒。湍动尺度效应导致叶片表面固相体积分数分布范围减小,大颗粒的变化值大于小颗粒,叶片头部和尾部的改变值大于中部,叶片表面的严重磨损部位为叶片工作面尾部的块状磨损区,这比采用传统算法得到的带状磨损区和偏磨区计算结果,更符合离心泵实际磨损情况,考虑湍动尺度效应后得到的磨损率也有所增大。在此基础上,提出了双吸离心泵叶片水力设计和表面喷涂防护原则,为提高双吸离心泵抵抗泥沙磨损能力奠定了基础。
[Abstract]:The calculation of solid-liquid two-phase flow has a direct effect on the simulation accuracy of sediment wear of double suction centrifugal pump. Based on the improved Euler algorithm of solid-liquid two-phase flow and considering the interphase resistance and sediment diffusion coefficient, the flow field of double-suction centrifugal pump under the condition of typical suspended sediment particle size is numerically calculated. It is found that the turbulence intensity on the surface of the blade is larger than that on the head and tail of the blade, and the particle dynamic scale of the head and tail of the blade is larger than that of the middle of the blade. The turbulent scale effect, which consists of turbulence intensity and particle dynamic scale, is strong in the blade head and tail. The turbulent scale effect increases the resistance between solid and liquid phases, which is more favorable to particle diffusion and avoids particle aggregation. The effect on large particles is stronger than that on small particles. The turbulent scale effect resulted in the decrease of the distribution range of solid volume fraction on the blade surface, the variation of the large particles was larger than that of the small particles, and the change value of the head and tail of the blade was larger than that of the middle part. The serious wear area on the blade surface is the block wear zone at the end of the blade face, which is more consistent with the actual wear condition of centrifugal pump than the calculation results of the belt wear zone and the partial wear zone obtained by the traditional algorithm. Considering the turbulent scale effect, the wear rate is also increased. On this basis, the hydraulic design and surface spray protection principle of double suction centrifugal pump blades are put forward, which lays a foundation for improving the resistance to sediment wear of double suction centrifugal pump.
【作者单位】：中国农业大学水利与土木工程学院;北京市供水管网系统安全与节能工程技术研究中心;中国水利水电科学研究院;
【基金】：国家自然科学基金项目(51321001) “十二五”国家科技支撑计划项目(2015BAD20B01)
【分类号】：TH311;O359

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