含固体颗粒竖直弯管段塞流/乳沫状流冲蚀速率预测

Prediction of erosion rate of solid particles in vertical pipe bends with slug flow/churn flow

关键词:  固体颗粒  冲蚀  弯管  段塞流  乳沫状流  段塞体  段赛单元  颗粒分布

Key words:  solid particle  erosion  pipe bend  slug flow  churn flow  slug body  slug unit  particle distribution

摘要:

气液混输管道中流体流动复杂，流体对管壁冲刷严重，管道中含有固体颗粒极大地加剧了管内介质对管壁的冲击，极易造成管道冲蚀破坏。为研究含固体颗粒管道在段塞流/乳沫状流下的冲蚀速率，提出种基于段塞体颗粒分布的冲蚀计算方法，在Eulerian坐标系下求解气液混合相连续相流场，Lagrangian坐标系下求解颗粒离散相运动轨迹，利用Oka，et al冲蚀模型及Grant和Tabakoff颗粒-壁面碰撞模型计算管壁冲蚀速率。结果表明：提出的CFD冲蚀计算模型计算结果与实验值最接近，且与Chen等的简化计算方法相比，精确度有较大提高；竖直弯管段塞流/乳沫状流中的固体颗粒主要位于段塞体和液膜中，段塞体和液膜中的固体颗粒分布不均匀，段塞体中固体颗粒含量较多；固体颗粒在段塞体中的分布系数约为0.827。

Abstract:

The flow in the gas-liquid mixed pipeline is very complex, and the wall erosion caused by fluid scouring is also serious. Therefore, solid particles entrained in the fluid greatly aggravate the impact on the wall, which may easily result in erosion damage. In this work, we have studied the erosion rate of solid particles in the pipe with slug flow/churn flow. We put forward the erosion calculation method based on the particle distribution in the slug body.The gas and liquid continuous phase flow field,and the particle trajectory are calculated in the Eulerian and Lagrangian coordinate system, respectively. The erosion rate is obtained by using Oka, et al erosion model, as well as Grant-Tabakoff particle-wall collision model. The results show that the calculation results by the proposed CFD erosion model are in perfect agreement with the experimental data, and this model is more precise compared with the simplified calculation process of Chen et al. The solid particles in the vertical slug/churn flow are mainly distributed in the slug body and liquid film;however, they are not distributed uniformly and there are more solid particles in the slug body. The distribution coefficient in the liquid is presented, and its value in the slug body is about 0.827.