压载水旋流器结构因素对分离性能影响分析

随着全球贸易和船舶运输的发展，压载水对环境的影响越来越大。水力旋流分离设备是压载水净化的重要固液分离设备。本文使用计算流体力学，建立数学模型模拟压载水旋流分离过程，模型包括多相湍流雷诺应力模型RSM、处理气液界面的自由表面多相流动模型VOF、处理固体颗粒运动规律的离散相模型DPM。通过数值模拟计算柱段长度、底流口直径和溢流口直径这几个关键因素对旋流器内部流场和分离效率的影响，获得了各个因素对分离效率的影响规律：柱段长度变化对旋流器分离效率的影响不大；底流口直径对旋流器压力降的影响不明显，但对分流比的作用比较大；溢流管直径的增大有助于降低能耗和增大溢流口流量，但随着溢流管直径的增大，分级粒度变大。这些规律为高效旋流分离净化压载水奠定了基础。

Analysis structural parameters of hydrocyclone used in ballast water on its performances

With the development of global trade and shipping transportation,the influence of ballast water on the environment is increasing.Hydrocyclone is a kind of important solid-liquid separation equipment for ballast water purification.In this paper,a mathematical model was established to simulate the separation process of ballast water by using computational fluid dynamics,including Reynolds Stress Model for turbulence,Volume of Fluid for multiphase flow and Discrete Phase Model for dispersed phase.Effects of key factors like different column length,spigot diameter and vortex-finder diameter on internal flow field and separation efficiency of hydrocyclone were studied through numerical simulation calculation.The influence of each factor on the separation efficiency was obtained.The length of the cylinder part has little influence on the separation efficiency; the diameter of the spigot has little effect on the pressure drop,but the effect on the flow ratio is relatively great; the increase of the diameter of the vortex finder decreases the energy consumption and increase the flow rate on the vortex finer.However,with the increase of the diameter of the vortex finder,the classified particle size increases.Those results can be as foundation for the high efficiency separation and purification of ballast water by hydrocyclone.