低浓度多相流管道冲蚀磨损数值模拟

液固多相流冲蚀磨损会严重影响管道的使用寿命。以某输油管线设计为研究对象,运用Fluent软件中的Mixture-DPM双向耦合模型研究低浓度颗粒的油水多相流管道流场变化,分析集输管线整体冲蚀速率分布,得到了不同管件冲蚀磨损较严重的区域。为了进一步研究冲蚀磨损的影响因素,选取3种不同的入口流速及原油含水率进行综合对比分析,结果表明：不同管件的冲蚀磨损区域各不相同;90°弯管磨损区域主要集中在外拱壁面,三通管磨损区域主要位于下支管右壁面,渐缩管磨损区域主要位于喉部区域及出口处,盲三通在盲端1/3处形成小型旋涡,且磨损区域主要位于盲端与下支管相贯线区域以及下支管右壁面处;冲蚀速率随入口流速的增加呈指数型增长,指数系数为1.89;随原油含水率增加,冲蚀速率呈倒"U"形变化,当含水率为20%时,冲蚀速率达到最大值。

Numerical simulation of the erosion wear of pipes with a low concentration of particles and multiphase flow

Erosion and wear by liquid-solid multiphase flow can seriously affect the service life of pipelines. The Mixture-DPM bidirectional coupling model in Fluent software has been used to study the flow field change of an oil-water multiphase flow pipeline with a low concentration of particles. The overall erosion rate distribution of the gathering pipeline has been analyzed, and the locations of serious erosion rate in different parts have been identified. In order to further analyze the factors influencing erosion wear, three different inlet flow velocities and crude oil moisture contents were selected for a comprehensive comparative analysis. The results showed that the maximum erosion wear zones of different pipe fittings vary. The wear area of a 90° elbow is mainly located on the outer arch wall, the wear area of a tee is mainly located on the right wall of the lower branch pipe, and the wear area of a gradual shrinkage pipe is mainly located on the throat area and outlet. A blind tee pipe forms a small vortex in the final third of the blind end and the wear area is mainly located at the intersection of the blind end and the branch pipe, and the right wall of the lower branch pipe. The erosion rate increases exponentially with increasing inlet flow velocity, with an exponential coefficient of 1.89. The erosion rate shows an inverted "U" shape with increasing crude oil moisture content. When the moisture content is 20%, the erosion rate reaches a maximum.