深海采矿循环式水力集矿系统设计与数值研究

Design and numerical study of a circulating hydraulic collecting system for deep sea mining

为使深海采矿作业更为高效、环保,提出了一种用于深海采矿的循环式水力集矿系统设计方案。该系统主要由集矿头、矿—沙分离器、水—沙分离器、水泵以及连接各部件的管道组成。采用基于欧拉法的液固两相流计算模型对该系统的关键问题,即矿—沙分离器和水—沙分离器的泥沙颗粒流动进行数值研究。相间拖曳力采用Richardson-Zaki模型。液相与固相湍流分别采用标准k-ε模型和Tchen湍流响应模型。该模型经验证对于直径0.165 mm与0.27 mm细颗粒具有较高精度。利用该模型,以0.165 mm泥沙颗粒为例,得到了两种分离器的分离效果与入口流速之间的规律,分析了两者颗粒浓度分布与流场特征。结果表明,两种分离器的性能均与入口流速有关,在选取适当入口条件时均可取得良好效果。

A conceptual design of circulating hydraulic collecting system for deep sea mining is proposed in order to make the mining operation more efficient and eco-friendly.The system mainly consists of a nodule collector,a nodule-sediment separator,a water-sediment separator,a pump and connecting pipes.Numerical study on sediment flow in the nodule-sediment separator and the water-sediment separator is carried out by using a Eulerian model for two-phase fluid-solid flows.Richardson-Zaki correlation is used for modeling drag force between phases.Standard k-εmodel and Tchen turbulence response model are used for simulating turbulence in fluid and solid phases,respectively.The model is validated to be accurate for fine particles of 0.165 mm and 0.27 mm in diameter.Separation performance of the separators of 0.165 mm particles is obtained under a series of inlet velocities.Distributions of particle concentration and flow characteristics of the separators are analyzed.The results show that the performance of the separators is related to the inlet velocity and can reach a good level under suitable inlet conditions.