颗粒负荷对小型旋风器性能影响的模拟分析

Simulation analysis of the effect of particle loadings on the performance of small cyclone

为探究颗粒负荷对小型旋风器内气固两相流动的影响,基于雷诺应力模型(RSM)和欧拉-欧拉方法的混合流模型(Mixture)进行气体-颗粒、颗粒-颗粒的相间耦合计算。采用粒径为0.5~5μm的颗粒组在40L/min、60L/min和80L/min的入口流量下模拟0~3kg/m3的5种不同颗粒浓度工况,通过对比旋风器内纯气相流场和颗粒负荷流场的不同,研究了颗粒的存在对流场的影响;探究了入口流量和浓度变化对旋风器内分离效率和压降特性的影响。基于模型有效性验证的数值模拟结果表明:较高颗粒浓度负荷使旋风器内的气相流场发生显著变化。随着入口流量的增大,旋风器的分离效率先增大后减小,压降呈非线性增大。随着颗粒浓度的增大,旋风器的分离效率逐渐增大,压降先减小后增大。

To investigate the effect of particle loadings on gas-solid two-phase flow in a small cyclone,the Reynolds stress model(RSM) and multiphase flow mixture model were adopted for the coupling calculation of gas and particles. Five different particle concentrations of 0-3 kg/m3 were simulated at the inlet flow rate of 40 L/min, 60 L/min and 80 L/min using a particle size of 0.5-5μm. The influence of the presence of particles on the gas flow field was studied by comparison of pure gas and particle-loaded phase in cyclone. The effects of inlet flows and solid concentrations on separation efficiency and pressure drop characteristics in cyclone were investigated. The simulation results based on the reliability verification showed that the gas flow field has significantly changes at high particle loadings. With the increase of inlet flow, the separation efficiency of the particles in the cyclone increases first and then decreases, while the pressure drop increases nonlinearly. As the particle concentration increases, the separation efficiency increases, while the pressure drop of the cyclone decreases first and then increases.