Abstract: In order to optimize the internal structure of airlift loop bed reactor and improve the gas liquid mass transfer efficiency, the two-phase flow process was simulated by using the Euler-Euler two-fluid model of CFD (computational fluid dynamics) and the standard k-ε model. The circulating fluid velocity was simulated at different axial height of the reactor riser, and the experimental values and simulation results were compared to verify the correctness of the physical simulation. According to the selected model, gas distributors were set at different coaxial positions of the reactor riser, and caps with different structures were set at the top of the riser. By comparing the distribution states of liquid velocity and gas holdup under different structures, the optimal structure of the reactor was obtained: the gas distributor was set at the bottom of the riser, that is inner-4, and the top of the riser cap was the Cap-2, at this time the circulating fluidization of the airlift loop bed reactor was in the optimal state and the gas-liquid mass transfer is the best.

Key words: CFD, airlift loop bed reactor, k-ε model;, gas distributor, the cap

摘要： 为优化气升式环流床反应器的内部结构、提高气液传质效率,采用计算流体动力学CFD的欧拉双流体模型和标准的k-ε双方程模型对两相流动过程进行了模拟。在反应器升流管不同轴向高度处对循环液速进行了模拟,并将试验值和模拟结果进行了对比,验证了物理模拟的正确性。根据所选模型,在反应器升流管不同轴向位置设置气体分布器,并在升流管顶部设置不同结构的帽罩。对不同结构下液速和气含率分布状态进行比较,得出了反应器的优化结构:气体分布器设置在升流管底部即Inner-4处,升流管顶部帽罩结构形式为Cap-2。此时气升式环流床反应器的循环流化处于最优状态,气液传质最佳。

关键词: 计算流体动力学CFD, 气升式环流床反应器, k-ε双方程模型;, 气体分布器, 帽罩