G-LISR不同气相入口流速对流场特性的影响

为了提高气液撞击流反应器(G-LISR)的混合性能,找到合适气相入口速度的操作参数,采用ANSYS Workbench中的Geometry模块,基于欧拉·拉格朗日法建立G-LISR气液两相流动数学模型。在加速管对置距离为400mm,液相入口速度为5m/s,三种不同的气相入口速度(10,15,20m/s)条件下,用数值模拟软件Fluent分析模拟出了不同气相入口流速下反应器内流场的分布特征。模拟结果表明:随着气相入口初始流速的增大,反应器内湍流强度有所增加,在压力波动最为剧烈的撞击面中心点处,压力急剧增大。增大气相初始流速,将降低反应器中的液滴的浓度分布,减少了液相在反应器中的停留时间。从能量损耗和气液两相在反应器中的混合效果来看,气相初始流速不宜过大,10m/s为较佳。

Influence of Different Gas Phase-inlet Flow Rate on Flow Field Characteristics of G-LIST

In order to improve the gas-liquid impinging stream reactor (G-LISR) mixing performance and find the operating parameters of the appropriate gas inlet flow rate,a mathematical model of G-LISR Gas-Liquid two-phase flow which based on the Euler-Lagrangian method was established by using the Geometry module in ANSYS Workbench.The numerical simulation software Fluent analysis was used to simulate the distribution characteristics of flow field in the reactor under the conditions of different distance of 400 mm between the two opposed accelerating tubes,liquid inlet rate of 5rn/s and three different gas inlet speed (10,15,20 m/s).The simulation results showed that with the increase of the initial velocity of the gas inlet,the turbulence intensity in G-LISR increased and the pressure increased sharply with the fluctuation at the center of the collision surface.With the increase of the initial gas-inlet velocity,both the concentration distribution of liquid particles and the liquid phase residence time in the reactor will be reduced.From the perspective of energy loss and gas-liquid two-phase mixing effect,the initial gas inlet flow rate should not be too large and 10 m/s was better.