深海采矿中继站底部Y形管流动状态研究

针对深海采矿泵管输送试验系统中Y形管内流场复杂和矿石泄露风险等问题，采用CFD-DEM方法，对不同速度、不同体积浓度和不同粒径的矿石颗粒进行数值模拟计算，分析了Y形管内颗粒群的运动特性和流场分布规律。结果表明，Y形管内流场分布受弯管曲率和Y形管入口流量分配影响；颗粒群在弯管内贴壁流动，受到上升流作用后颗粒向上偏移；当上升流流速不足、颗粒体积浓度高及颗粒粒径较大时，会造成颗粒沿着底部管道流失，随着上升流速减小、颗粒体积浓度增大及颗粒粒径增大，颗粒通过底部管道流失不断增大；颗粒流的存在导致Y形管内低压漩涡区强度和尺度均减弱。

Flow State of Y-shaped Pipe at Bottom of Buffer Station in Deep-Sea Mining

Aiming at complicated flow field of Y-shaped pipe in pump piping system and risk of ore leakage in conveying test for deep sea mining, numerical simulation was performed by using CFD-DEM method for ore particles with different velocities, different volume concentration and different particle sizes. Based on that, the movement features of particle groups and flow field distribution pattern in Y-shaped pipe were all analyzed. It is found that the flow field distribution in Y-shaped pipe is influenced by the curvature of pipe elbow and the flow distribution in the inlet of Y-shaped pipe. The particle groups flow against the inner wall of elbow, and deflect upward under the influence of upward flow. If upward flow with lower velocity, particles with large grain size and high volume concentration will hit the bottom of pipe, leading to some losses. As the upward velocity decreases and both particle volume concentration and grain size increase, more and more particles will be continuously lost on the bottom of pipe. Due to the existence of particle flow, both intensity and scale of the low-pressure vortex region in Y-shaped pipe become weaken.