【作者】 吴玮；

【导师】 李希；

【作者基本信息】 浙江大学 ， 化学工程， 2012， 硕士

【摘要】 反应器微型化是化工过程强化的重要研究方向,本文对微反应器微通道内流体的流动、混合、传质性能展开详细研究,并对微通道网络结构进行了仿生设计与优化。本文首先对单级和多级T形微通道结构中互溶两相流体的混合规律进行了实验和模拟研究。随着流动雷诺数的增加,微通道内依次出现层流、涡流、卷流三种不同流动状态。在相同停留时间条件下,多级T形微通道结构中流体混合效率明显高于单级。研究结果说明,含有多级T形结构的树状分形仿生网络结构能够极大地强化流体混合,是一种高效的微混合构型。进一步地,分别对单级和双级T形微通道结构中水和甲苯体系,CO2和水体系两相流动与传质进行了实验与模拟,拍摄了两相流动流型变化。测量了醋酸在水和甲苯两相中的分配获得了T形微通道中液液两相传质系数,通过对T形微通道内水物理吸收C02过程的测定获得了气液两相传质系数。采用VOF流体力学模型模拟了T形微通道中液液、气液两相不同流型的形成和变化过程,准确预测了弹状尺寸。研究发现,含有多级T形结构的分形树状仿生网络能够有效地提高液液、气液两相间的传质速率,是一种高效的微萃取、微吸收构型。最后,借鉴生物循环系统的原理和结构特征,设计了一种具有进料、出料微通道网络分布的整体式仿生催化剂芯片。对仿生通道网络构型进行了CFD模拟研究和优化计算。具有仿生通道网络分布的整体式仿生催化剂芯片流动阻力低,返混小,抗干扰能力强。探索了仿生催化剂芯片在三个典型反应体系的应用,模拟结果表明仿生催化剂芯片能够实现高的反应转化率,该催化剂芯片结构是一种高效的构型。更多还原

【Abstract】 Reactor miniaturization is an important research in chemical process intensification. In this paper, fluid mixing and mass transfer in T-shaped micro-channel as well as design and optimization of bionic micro-channel network were carried out. The works include the following three parts:Firstly, a series of high-resolution CFD simulations as well as experiments were implemented to investigate the mixing in single-stage and multi-stage T-shaped micro-channel networks. With the increasing Reynolds number, three different flow regimes namely stratified flow, vortex flow and engulfment flow regime were observed. Under the same residence time, the mixing efficiency is higher in multi-stage T-mixer than the single one. Bionic networks containing multi-stage T-shaped micro-channel greatly enhance the micro-mixing, and this kind of network is a powerful micro-mixing configuration.Secondly, CFD simulations and experiments were adopted to investigate flow and mass transfer of liquid-liquid/gas-liquid phases in single and double T-shaped micro-channel networks. Liquid-liquid/gas-liquid mass transfer rates were measured respectively based on distribution of acetic acid in water-toluene system and water physical adsorption of carbon dioxide process. Moreover, volume of fluid model (VOF) was implemented to simulate the generation and development of slug flow, predict the slug length. Tree-shaped networks containing multi-stage T-shaped micro-channel greatly enhance the liquid-liquid/gas-liquid mass transfer in micro-channels, and this kind of network is both a high-efficient micro-extraction and micro-adsorption configuration.Thirdly, according to principles and features of biological circulatory system, a novel monolithic catalyst chip with bionic micro-channel network configuration was proposed. It was a multi-stage and multi-function network with separated inflow and outflow systems. CFD simulations and optimizations were implemented to investigate the characteristic of the bionic network. Flow resistance was greatly reduced and back-mixing was lowered by using bionic micro-channel network. Strong robustness was verified for monolithic catalyst chip with bionic network configuration. Three typical catalyst reactions were applied to the design of bionic catalyst chips. High conversions were achieved in chips which were verified to be an efficient configuration.更多还原