基于简化模型的T型微反应器设计

Optimal design of T-shaped microreactors by using a simplified model

分析T型微反应器内流体混合程度和反应产物收率的常用方法:是建立计算流体动态模型,也就是CFD模型,可是这种模型不适用于微反应器的优化设计,因为利用CFD模型进行优化计算需要的大量的计算时间。本研究开发了一个描述T型微反应器流体流动状态的简化模型,通过假设边界条件和假设扩散系数的设定来计算微反应器内反应产物收率。其中假设边界条件用来描述强混合效果在反应通道入口处的流动状态,假设扩散系数用来描述混合效果在流动路径上的变化。本研究依据此简化模型,确立了一种优化设计方法:,用来设计具有最优尺寸的T型微反应器。优化问题的目标函数是最大反应产物收率,优化约束包括反应通道尺寸约束和操作压力约束。在求解过程中,首先建立尺寸约束边界条件下的CFD模型,然后依据CFD模型计算结果:,求解简化模型中的未知参数。将建好的简化模型作为优化问题的等式约束,最后求出最优的T型微反应器。简化模型和优化设计方法:的有效性通过一个快速平行串联反应在微反应器中的反应过程来验证。简化模型的优化设计结果:和CFD模型验证结果:高度一致。

Computational fluid dynamics models are effective in rigorously analyzing T-shaped microreactors. However, when they are applied to optimal design problems, it is necessary to reduce computational time. In this research, a simplified model is proposed to efficiently solve the optimal design problems of T-shaped microreactors. In the proposed model, the assuming boundary conditions and an artificial diffusivity are used to calculate the reaction yield distribution in the mixing channel. The assuming boundary conditions are used to describe the mixing effect on the inlet of the reactor, and the artificial diffusivity is used to express convective mixing caused by the flow through diffusive mixing. Meanwhile, based on the simplified model, an optimal design method is proposed to calculate the optimal size of T-shaped microreactors. The usefulness of the proposed model and the optimal design method is demonstrated through a fast consecutive-parallel reaction. The reaction yield is maximized by manipulating the width, height and length of mixing channel of an isothermal T-MR that meets the prescribed requirements for the pressure drop. The design result shows that the simplified model can accurately predict the yield distribution of the product along the mixing channel and that the simplified model based design method can reduce the design period of T shaped microreactors.