高通量连续流微反应器的流动与传热数值模拟

Simulation of Flow and Heat Transfer in the High-Throughput Continuous-Flow Microreactor

微反应器作为一种连续流反应器,已广泛应用于各类有机合成反应过程,但是由于微尺度限制了流动通量,其大规模工业应用仍有诸多困难。本研究通过在流体通道中内置三维螺旋构件的思路设计出一种高通量连续流微反应器。介绍了该反应器的几何构型与功能特点,并采用计算流体力学模拟基本单元的对流传热过程。结果表明:流体在内构件的作用下产生大量二次流,显著强化了传热过程,流动径向上温度近乎均一。雷诺数、普朗特数与几何结构对传热过程影响显著,通过数值拟合得到努塞尔数与摩擦系数的计算关联式。

As a kind of continuous-flow reactor,the microreactor has been widely used in various organic synthesis reactions.However,the large-scale industrial application of microreactors is difficult because the flow flux is limited by the microscale.In this paper,a high-throughput continuous-flow microreactor was designed based on the idea of embedding three-dimensional spiral components in the channel.The geometric configuration and functional characteristics of the reactor were introduced,and then the convective heat transfer process of the basic unit was simulated by computational fluid dynamics.The results showed that the fluid generates a large number of secondary flows with the action of the internal components,which significantly enhanced the heat transfer process,therefore the temperature in the radial direction of the flow was nearly uniform.The Reynolds number,Prandtl number and geometric structure had significant effects on the heat transfer process.The correlation equations of Nusselt number and friction coefficient were obtained by numerical fitting.