旋流分离器油水分离效率的模拟研究

Numerical simulation of oil-water separation efficiency of a hydrocyclone

采用计算流体力学的方法,探讨了操作条件和物料特性对旋流分离器分离油水效率的影响。旋流器为单锥双入口,其主直径为50 mm,锥角为5.5°。模拟过程中,采用商业用软件‘Fluent 6.3’中的雷诺应力模型和欧拉多相流模型来模拟不同条件下油水旋流分离器的分离性能。模拟结果表明,对于本研究的油水旋流分离器,最佳的分流比是10%,最佳的油滴浓度是0.5%(V/V)。在最佳的分流比和油滴浓度下,当进口流速为10.46 m/s时,油水旋流分离器可将15μm的油滴去除80%以上,油滴的分离界限粒径d50(50%的分离效率)为9.2μm。在模拟的基础上,用统计软件STATISTICA6.0对分离效率与操作条件和物料特性之间的关系进行拟合。通过拟合式预测的分离效率与实测值相吻合,误差小于15%。

The Eulerian multiphase model and Reynolds-stress model（RSM）,validated with experimental data,were used to simulate the separation efficiency of an oil-water hydrocyclone under different conditions,using the computational fluid dynamics（CFD） software ’Fluent 6.3’.The hydrocyclone had a diameter of 50 mm,with two inlets and a single cone,the cone angle θ was 5.5°.The results show that for the oil-water hydrocyclone,the optimal flow rejection ratio was 10%,and the optimal oil droplet concentration was 0.5%（V/V）.Under the conditions the hydrocyclone could remove 〉80% of 15 μm oil droplets,and the cut-off size for 50% separation efficiency was 9.2 μm,when the inlet velocity was 10.46 m/s.A mathematical correlation between separation efficiency and operating conditions/feed characteristics was derived based on the simulation results,with the aid of software STATISTICA for Windows version 6.0.The predicted oil-water separation efficiency using the mathematical correlation agreed well with the experimental results with a deviation below 15%.