液压油箱用固液旋流分离器分离效率影响规律

颗粒物污染是影响移动装备液压元件及系统性能的主要原因之一，液压油箱考虑去除杂质功能会增加其设计容积，不利于液压系统轻量化设计。应用离心分离的原理，使不同密度的介质在高速旋转的流场中进行分级筛选，可快速去除液压油中大颗粒污染物，提高液压系统可靠性，提升过滤器使用寿命。由于旋流分离器中流场的流动形式复杂，预测旋流分离器内部的流场特性、颗粒运动轨迹十分困难。因此，研究旋流分离器流场流动规律和污染物旋流分离机理，可以为液压系统污染物分离和去除提供理论基础。针对固液旋流分离器的流场分布规律和污染物分离效率的影响规律展开研究。根据旋流分离理论设计了固液旋流分离器结构，分析旋流分离器不同直径和长度下，固液旋流分离器轴向速度、切向速度的分布规律，通过粒子图像测速法对仿真结果进行试验验证，得到结构参数对分离效率的影响规律。结果表明，当中心的轴向速度为负值、壁面附近的轴向速度为正值时，切向速度越大，越有利于分离液压油中的颗粒。该研究结果可对液压油箱用固液旋流分离器的结构设计提供理论指导。

Influence Law of Separation Efficiency of Solid-liquid Cyclone Separator for Hydraulic Tank

Particulate matter pollution is one of the main reasons that affect the performance of hydraulic components and systems of mobile equipment. Considering the removal of impurities in the hydraulic tank, it will increase its design volume, which is not conducive to the lightweight design of the hydraulic system. Using the principle of centrifugal separation, the media of different densities are classified and screened in the high-speed rotating flow field, which can quickly remove large particles of pollutants in the hydraulic oil, improve the reliability of the hydraulic system and increase the service life of the filter. Due to the complex flow form of the flow field in the cyclone, it is very difficult to predict the characteristics of the flow field and the particle movement trajectory inside the cyclone. Therefore, the study of the flow law of the cyclone flow field and the swirling separation mechanism of pollutants could provide a theoretical basis to the hydraulic system pollutants separation and removal. This article focused on the flow field distribution law of the solid-liquid cyclone separator and the influence law of pollutant separation efficiency. According to the cyclone separation theory, the structure of the solid-liquid cyclone separator was designed, and the distribution law of the axial velocity and tangential velocity of the solid-liquid cyclone separator was analyzed under different cylinder diameters and cylinder lengths. The simulation results were carried out by the particle image velocimetry method. The experiment was verified, and the influence law of the structure parameter on the separation efficiency was obtained. The results show that when the axial velocity at the center is negative and the axial velocity near the wall is positive, the separation effect increases with the increase of tangential speed. The research results can provide theoretical guidance for the structural design of solid-liquid cyclone separators for hydraulic tanks.