旋流反应器内颗粒停留时间分布的CFD模拟

采用欧拉双流体模型对旋流反应器内气固两相流动进行数值模拟,附加无反应组分输运方程研究颗粒停留时间分布(RTD),并考察了操作参数和催化剂粒径对RTD的影响。结果表明,旋流反应器内RTD曲线为单峰分布,切向入口气速越大,颗粒RTD无因次方差减小,流动越接近平推流。增大颗粒循环量可减少颗粒平均停留时间,但加剧了颗粒返混。此外,平均停留时间随颗粒粒径增大,呈现出先增大后减小的趋势,且颗粒越小,返混越严重。

CFD Simulation of Particle Residence Time Distribution in Cyclone Reactor

Gas-solid two-phase flow of cyclone reactor was simulated with the Euler double fluid model, and the particle RTD （residence time distribution） in the reactor was studied by using species transport equation with no reaction. Effects of operating parameters and catalyst size on RTD were investigated. The results show that the particle RTD curves of cyclone reactor are uni- modal. With the gas velocity of tangential inlet increased, the particle RTD dimensionless vari- ance decreases, and particle flow trends to plug flow. Increasing the particle circulation can re- duce the mean residence time but aggravate back mixing. It is found that, the particle mean resi- dence time increases first and then decreases with the increase of the particle size, and the small particles are more likely to be back mixing.