【作者】 王彦伟；

【导师】 吴嘉；

【作者基本信息】 浙江大学 ， 化学工程， 2002， 硕士

【摘要】 振荡流混合反应器(Oscillatory Flow Reactor，以下简称为OFR)以其优越的性能(良好的质量传递、热量传递，工艺过程容易控制等)正引起人们的广泛关注。以各种不同的方法对它的各种性能的研究已经取得了一些很有价值的成果。作为一种性能优良的新型的反应设备，它可以应用到化学工程等很多领域，如粒子的悬浮与分离、絮凝工艺、化工反应器、过滤、生物科学、医药科学等。 本文利用CFD方法，对OFR流场中停留时间分布(RTD)进行模拟研究，探讨振荡流混合反应器重要操作参数——振荡雷诺数Reo对RTD的影响。 本文的工作主要集中研究在层流流态下，一定净流量的三维OFR流场中示踪粒子停留时间的分布情况，通过后处理获得不同反应器类型(八腔室OFR、四腔室OFR、基本管式反应器、带挡板管式反应器)、不同Reo下RTD曲线，并根据曲线的形状进行定量的分析，建立反应器内混合模式的唯象模型。 本文首次实现了三维OFR流场中RTD的模拟，并成功地获得了1000个示踪粒子的RTD曲线。同时针对八腔室和四腔室情况，分别采用了八个和四个带级间返混的串联全混釜唯象模型进行了比较研究，通过对级间返混比的优化调整，对应的唯象模型能够较好地描述OFR的RTD特性，而可调整模型参数——级间返混比的数值随Reo和腔室数目的改变发生显著变化。 本文的工作为进一步的研究打下了良好基础。在OFR流场RTD数值模拟的基础上可以进一步进行OFR中化学反应过程的数值模拟研究。更多还原

【Abstract】 Great interest has been input on Oscillatory Flow Reactors (OFR), which has good performance in momentum, heat, and mass transfer. The transfer processes in an OFR can be well controlled by changing the frequency and amplitude of fluid oscillation. Many potential applications of OFR in chemical engineering have been explored, such as particle suspension and separation, flocculation, filter, chemical reactors, separation processes in bioengineering and pharmaceutical engineering.In this thesis, CFD method was used to simulate the Residence Time Distribution (RTD) in an OFR. The influence of some main factors on RTD, such as oscillatory Reynolds number (Red), number of cells in an OFR, and net flow rate, were studied.Our work focused on computating the residence time of tracing particles in three-dimensional laminar flow with a constant net flow rate in an OFR. The RTD curves in different Reo were obtained through post-treatment for four-cell, eight-cell OFRs and baffled and non-baffled tube reactors. Based on the shape RTD curves, a kind of phenomenological models of mixing patterns was built up.It’s the first time to implememt the simulation of RTD in three-dimensional OFR flow field, and to obtain RTD curves with 1000 tracing particles. Referring to the results with 4 and 8 cells, the phenomenological models of 4 and 8 CSTRs in series with inter-stage back-mixing were used to carry out a comparitive study. By optimal reconciliation of the back-mixing ratio, the phenomenological models can describe RTD figures of OFR quite well. The adjustable model parameter, back-mixing ratio, varied obviously with Reo and number of cells changing.The work presented here will be very helpful to the following research. Base on the result of numerical simulation of RTD in OFR, futher simulation study on chemical reaction process in OFR can be carried out.更多还原