气液两相流在平行微通道内的相分配特性

Uneven distribution and phase separation of gas-liquid two-phase flow are the two key issues restricting the applications of parallel microchannel devices.The study of two-phase distribution in parallel microchannels has important theoretical and practical values for the design and application of microchannel system. Aim at the phase separation of gas-liquid two-phase flow in parallel microchannels,the project intends to study the main scientific issues listed as follows: (1)the visual observation and phase distribution characteristics of two-phase flow in parallel microchannels under different inlet flow patterns; (2) to design different geometrical conditions,including different shapes of the head, the number and the pitch of the channels, and to clarify their effect on the phase distribution; (3) to study the effect of fluid properties, such as surface tension, vescosity, and wettability on the phase distribution of two-phase flow in microscale. Through combining theoretical and experimental research methods, we will clarify the key factors affecting the gas-liquid two-phase distribution in parallel microchannels,and establish the theoretical models to predict two-phase distribution in parallel microchannels, to provide the theoretical guidance for the development and application of micro reactors and micro heat exchangers.

气液两相流的流量分布不均以及气液相的偏流现象是平行流微通道器件应用所面临的两个关键问题，它们的研究对微通道系统的设计与利用具有重要的理论意义和应用价值。本项目拟将针对气液两相流在平行微通道的偏流特性，进行以下几个方面的研究：（1）不同入口流型条件下气液两相流在平行流通道中的可视化观察与相分配特性研究；（2）设计并探索不同几何结构（包括封头形状、支管数目和支管间距等因素）对相分配特性的影响；（3）考察微小尺度内流体物性(表面张力、黏性、润湿性)对相分配特性的影响。通过以上实验与理论研究相结合的方法，探明影响气液两相流在平行微通道的相分配的关键因素，建立气液两相在各支管分配的理论预测模型，为微型反应器、微型换热器的开发和应用提供理论指导与基础支撑。

本项目主要以实验手段，探索微小尺度平行流微通道内相分配的影响因素及其影响机理。设计和加工了不同的平行流微通道结构（包括不同管径、管间距和支管数量等）、配置了不同物性的流体工质（不同表面张力和粘度)，利用目前实验室所具备的可视化手段，进行了一系列的相分配可视化实验，观察了微观尺度内的相分配规律，同时利用微流体控制/测试设备获得了气液两相流在各个分支内具体的气相和液相的分配量，弄清了微尺度下主导气液相分配的几个因素（几何结构，入口流型及流体物性）的影响。接着在实验数据的基础上，建立了平行流微通道内气液两相分配的经验关系式，能够较为准确地预测其两相分配行为。本项目已经发表SCI论文19篇（计划发表SCI论文7-8篇），研究成果有助于深入、全面的揭示气液两相流在平行流微通道内的相分配规律，为其在微小型电子散热和微型反应器产量放大提供理论指导和技术支撑。