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

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

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.