微通道内弹状流型下泄漏流的流动、传质、混合及其耦合机理与调控

Gas-liquid/liquid-liquid slug flow in microchannels is an ideal flow pattern for intensification of two-phase processes. In this flow pattern, leakage flow which initiates from the continuous phase bypassing through the space between the gas bubbles/liquid droplets and the channel walls has rarely been paid attention to by researchers. As leakage flow has a significant influence on the transport and reaction phenomena, understanding and regulating it are of great importance to the slug flow theory and application. This project aims at investigating the occuring condition and characteristics of leakage flow using several methods, such as high speed shooting, double-light path lightening, numerical simulation and so on. With the help of Navier-Stokes Equations and lubrication theory, the research allows a deep exploring of the drive force of leakage flow, which then enables a targeted manipulation. As to mass transfer and mixing behavior, this project plans to investigate the mass transfer, local mixing and marco mixing (RTD) characteristics under conditions with different leakage flows using various methods, including aser-induced fluorescence, online spectral absorption and numerical simulation. The results will provide a thorough understanding on the influences of leakage flow on mass transfer and mixing and their coupling mechanism. The upcoming results from this project will also provide a better theoretical basis and technical supporting for the slug flow regulation and reactor design.

微通道内气-液/液-液弹状流是强化两相过程的理想流型。该流型下连续相通过气泡/液滴与通道壁面间的缝隙流动而形成的泄漏流是较少被关注的现象。由于泄漏流对“三传一反”过程产生显著的影响，认识和调控泄漏流、掌握其对传质和混合特性的影响对于弹状流的理论发展和实际应用具有十分重要的意义。本课题拟采用高速显微摄像、双光路照明和数值模拟等方法，研究气-液和液-液体系下泄漏流的发生条件和流动特征，通过Navier-Stokes方程和润滑理论分析其驱动内因，进而构建和发展泄漏流理论及其调控手段。结合荧光诱导、在线光谱吸收和数值模拟等方法分别对不同泄漏流条件下两相流动过程中的传质、混合及停留时间分布等特征进行研究，探索泄漏流与传质和混合之间的耦合机理和调控规律，为高效率调控弹状流和反应器设计开发提供理论依据和技术支持。

本项目通过实验手段，结合理论分析和数值模拟方法，对微通道内弹状流型下泄漏流的流动和传递过程进行研究，聚焦微尺度下泄漏流的流动行为和调控规律、泄漏流影响下的界面演变及界面传质两个关键科学问题，重点探索了：1）微通道内宽粘度范围泄漏流和弹状流的流动与传递特性；2）液膜和泄漏流的流动/传递行为对气-液/液-液和气-液-液弹状流的影响机制；3）基于液膜和泄漏流影响原理的弹状流过程强化与应用三方面的研究。项目研究工作揭示了弹状流型下泄漏流的形成与流动特征和泄漏流对弹状流流动与传递的影响规律。研究过程中发展和完善了双光路照明法、刃天青-O2反应显色法等多相流动、传质和混合的在线表征方法；量化了泄漏流并考察了影响因素，建立了泄漏流的预测关联式；揭示了泄漏流对多相流形成过程、流动稳定性、界面传质的影响机制，建立了数学描述模型，为宽操作范围流型调控和传质预测提供了新策略和新模型；基于液膜、泄漏流和弹状流基础研究，指导设计了新型微反应器，应用于二氧化碳吸收和烷烃/烯烃分离过程，实现了过程强化。.. 本项目执行期间培养硕士研究生2名，博士研究生1名，发表学术论文19篇（其中SCI论文18篇），申请发明专利2篇。项目负责人入选中科院青年创新促进会会员，大连化物所“优秀青年博士人才”和“张大煜青年学者”、中国化工学会过程强化专委会青年委员会委员。项目执行期间，受邀在国内国际做主旨或邀请报告10余次。

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