海底管道沙粒侵蚀的数值模拟及侵蚀公式评价

Numerical simulations of sand erosion in pipelines and evaluations of solid particle erosion equations

海底管道中颗粒侵蚀是油气输送过程面临的一个重要问题,也是流动保障的一个重要分支。弯头和T型堵头管是油气生产中最易于发生颗粒侵蚀的管道组件。首先使用剪切压力传输模型(SST)计算管道内流场,使用拉格朗日方法跟踪颗粒运动轨迹,结合颗粒随机反弹模型,建立跟踪复杂流场中大规模颗粒运动轨迹的一般方法;之后引入四种颗粒侵蚀公式,预测弯头、T型堵头管的砂粒侵蚀结果,并结合实验数据,比较分析各侵蚀公式的精度与适用性。分析结果表明,对于弯头,四种侵蚀公式的数值结果与实验结果均吻合良好,其中Tabakoff的侵蚀公式具有较高的精度和较好的适用范围;对于T型堵头管,数值方法对颗粒运动机理的模拟尚存缺陷,需做进一步改进。

Solid particle erosion is a severe problem involved in hydrocarbon transportation. In the present study, a generalized numerical method has been established to calculate the penetration rates in elbows and plugged tees which are most easily eroded among all the pipeline components. The procedure consists of three main sections： flow modeling, particle tracking and penetration calculation. The shear stress transport model is employed to analyze the flow field and a Lagrangian method combined with particle stochastic rebound model is adopted to track the particle trajectories. Based on the knowledge of the flow field and the particle motions, four solid particle erosion models are introduced to calculate the penetration rates and the model performances are discussed deeply. Compared with the experimental data available in literature, all the erosion models show good prediction accuracy for elbow geometries and the results obtained from Tabakoff erosion model are closer to the experiment values. Conversely, an obvious disagreement between numerical results and experimental data can be observed due to the mechanism of particle motions for plugged tees.