Flow field characteristics of gas-inducing hydrogenation reactor with CFD simulation

doi:10.16085/j.issn.1000-6613.2017.03.011

Abstract

Abstract:

The gas-inducing reactors have been widely used in the hydrogenation technology of dinitrotoluene and other multiphase reactions. The flow fluid inside the reactors is very complex. Relying on the experiment is difficult to obtain comprehensive and accurate results. The object of this study was gas-inducing hydrogenation reactor. Computational fluid dynamics(CFD) Fluent was used to establish the three-dimensional reactor model. Eulerian two-fluid method was applied to study gas-liquid flow field in hollow paddle and double-disk impeller gas-inducing reactors. CFD was also used to visualize detailed flow phenomena. The characteristics of gas induction in hollow paddle gas-inducing reactor were contrasted with the experimental dates to verify the CFD model. Contours of local air volume fraction and vector plots of velocity of the reactors were obtained and contrasted. The results showed that the simulation results were in good agreement with the experimental dates. For reactor with single paddle,the gas-liquid dispersion performances and gas induction in hollow paddle gas-inducing reactor were better than those in double-disk impeller gas-inducing reactor with same pitch diameter.

Key words: multiphase reactor, computational fluid dynamics(CFD), gas-liquid flow, numerical simulation

摘要：

目前自吸式反应器广泛应用于二硝基甲苯加氢等多相流反应过程，但由于其内部流动十分复杂，单纯依靠实验很难得到全面准确的研究结果。为了解决这一问题，以自吸式加氢反应器为研究对象，运用计算流体力学（CFD）Fluent建立三维反应器模型，采用欧拉两相流方法，对空心叶轮自吸式反应器与双圆盘叶轮自吸式反应器内的气液两相流动特性进行了研究，将反应器内的流动可视化。在此基础上将空心叶轮反应器内的吸气特性与实验数据进行对比，验证建立的CFD模型，并对比两种反应器内的局部气含率分布与液相速度矢量图分布。结果表明：空心叶轮自吸式反应器吸气特性的模拟结果与实验结果吻合较好；对于单层桨叶自吸式加氢反应器，相同桨径的空心叶轮比双圆盘叶轮的吸气性能与气液分散性能更好。

关键词: 多相反应器, 计算流体力学, 气液两相流, 数值模拟

CLC Number:

LIU Tiantian, LI Yugang, ZHENG Shiqing. Flow field characteristics of gas-inducing hydrogenation reactor with CFD simulation[J]. Chemical Industry and Engineering Progress, 2017, 36(03): 846-851.

刘甜甜, 李玉刚, 郑世清. CFD在自吸式加氢反应器流场研究中的应用[J]. 化工进展, 2017, 36(03): 846-851.

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