Wu Yuanyuan, Hong Tao, Tang Zhengming, Zhang Chun
College of Information Science & Technology, Chengdu University of Technology, Chengdu 610000, China.
School of Electronic Information Engineering, China West Normal University, Nanchong 637002, China.
Entropy (Basel). 2018 Apr 2;20(4):241. doi: 10.3390/e20040241.
The aim of this work is to present a model of a reaction tube with cross structures in order to improve ethyl acetate production and microwave heating uniformity. A commercial finite element software, COMSOL Multiphysics 4.3a (Newton, MA, USA), is used to build the proposed model for a BJ-22 rectangular waveguide system. Maxwell's equations, the heat conduction equation, reaction kinetics equation and Navier-Stokes equation are combined to describe the continuous flow process. The electric field intensity, the temperature, the concentration of water, the coefficient of variation () and the mean temperature at different initial velocities are compared to obtain the best flow rate. Four different initial velocities are employed to discuss the effect of flow velocity on the heating uniformity and heating efficiency. The point temperatures are measured by optical fibers to verify the simulated results. The results show the electric field intensity distributions at different initial velocities have little difference, which means the initial velocity will have the decisive influence on the heating process. At lower velocity, the will be smaller, which means better heating uniformity. Meanwhile, the distance between each cross structure has great influence on the heating uniformity and heating efficiency, while the angle has little. The proposed model can be applied to large-scale production of microwave-assisted ethyl acetate production.
这项工作的目的是提出一种具有交叉结构的反应管模型，以提高乙酸乙酯的产量和微波加热均匀性。使用商业有限元软件COMSOL Multiphysics 4.3a（美国马萨诸塞州牛顿市）为BJ - 22矩形波导系统建立所提出的模型。将麦克斯韦方程组、热传导方程、反应动力学方程和纳维 - 斯托克斯方程结合起来描述连续流动过程。比较不同初始速度下的电场强度、温度、水浓度、变异系数（）和平均温度，以获得最佳流速。采用四种不同的初始速度来讨论流速对加热均匀性和加热效率的影响。通过光纤测量点温度以验证模拟结果。结果表明，不同初始速度下的电场强度分布差异不大，这意味着初始速度对加热过程具有决定性影响。在较低速度下，变异系数会更小，这意味着加热均匀性更好。同时，各交叉结构之间的距离对加热均匀性和加热效率有很大影响，而角度影响较小。所提出的模型可应用于微波辅助乙酸乙酯生产的大规模生产。
