深海采矿扬矿泵内固体颗粒运动特性数值模拟

针对深海采矿输送系统中扬矿泵易堵塞和磨损等问题,采用标准κ-ε湍流模型求解扬矿泵内流场,并运用离散相模型模拟颗粒流动轨迹,研究了颗粒粒径、导叶进口安放角、导叶数量对扬矿泵堵塞及磨损特性的影响。结果表明,总体上,颗粒在导叶1区与前盖板碰撞次数最多,对导叶前盖板磨损严重;在3、4区与压力面碰撞次数最多,颗粒与导叶碰撞主要起到改变颗粒运动轨迹的作用,对3、4区的导叶压力面的磨损并不严重。随着粒径增大,平均过导叶时间和碰撞次数呈增加趋势,且增加了颗粒与吸力面碰撞的可能性。随着导叶进口安放角增大,平均碰撞次数和平均过导叶时间均随之增加,颗粒与压力面碰撞区域越靠近导叶进口处,对压力面进口造成的磨损越严重。随着导叶数量增加,过导叶时间有减小的趋势;颗粒与导叶压力面碰撞位置向导叶中部移动,对压力面的磨损程度较轻。

Numerical Simulation of Particle Motion Trajectory in Lifting Pump for Deep-sea Mining

Aiming at the blockage and wear-off of lifting pump in deep-sea mining transportation system, the fluid field of the lifting pump was solved by the standard κ-ε turbulence model and the particle flow trajectories was simulated with a discrete phase model, and effects of particle diameter, guide vane inlet-stagger-angle and number of guide vanes on the blockage and wear characteristics of lifting pump were investigated. Results showed particles generally collided most frequently with the front cover plate in the first partition of the guide vane, leading to a serious abrasion in this area, and also frequently with the pressure face in the third and fourth partition of guide vane. The collision between particles and guide vane predominantly changed particles trajectory and led to less abrasion on the pressure face of guide vane. With an increase in particle size, both the average time for particles passing through the guide vane and numbers of collision with guide vane were on the rise, which increased the possibility of particles colliding with the suction surface. With the increasing of guide vane inlet-stagger-angle, an average time for particles passing through vanes and average collision numbers were all increased. It is found that the collision of particles with pressure face that is closer to the inlet of the guide vane blade, will lead to more serious abrasion of the inlet of pressure face. With an increase in the guide vane numbers, the time for passing through the vane was shortening. And with the collision of particles with the pressure face of guide vane moving to the center part, the pressure face became less worn off.