虚旋风气溶胶分级采样器的采样机理及其应用

项目名称： 虚旋风气溶胶分级采样器的采样机理及其应用

项目编号： No.41275164

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 向荣彪

作者单位： 华中农业大学

项目金额： 80万元

中文摘要： 气溶胶颗粒的分级采样在大气气溶胶研究中具有重要的意义。常用的惯性冲击采样器和旋风分离采样器存在颗粒反弹、破碎、再悬浮等缺陷，虚旋风采样器一定程度上可以克服上述缺陷，但目前对其内部气流及颗粒的运动规律认识不清，限制了虚旋风采样器的应用。本研究拟利用计算流体力学（CFD）理论建立模拟虚旋风分级采样器内气固两相运动的数学模型，结合实验测试，探讨虚旋风分级采样器内气流及颗粒的运动规律，分析该类型采样器的结构尺寸和采样流速等设计、运行参数与气固两相运动的内在联系，找到实现非冲击采样的最佳设计和运行参数。在此基础上，完成新型PM2.5采样器的原型设计及性能验证，评估该采样器用于生物气溶胶采样的效果。项目完成后将为基于虚旋风概念的新型PM2.5分级采样器及生物气溶胶采样器的设计与开发提供理论指导。

中文关键词： 气溶胶；分级采样；虚旋风采样器；机理；性能评估

英文摘要： Size-segregated sampling of aerosol is of primary importance for the atmospheric aerosol research. Drawbacks, including particle bounce, break-up, and re-suspension, are associated with the widely used inertial impactor and cyclone sampler. Virtual cyclone can overcome these drawbacks to a certain extent. However, due to the poor understanding about the fluid flow dynamics inside the virtual cyclone, application of virtual cyclone is so far limited. Based on the Computational Fluid Dynamical (CFD) theory, a numerical model is expected to be developed to simulate the particle and gas flow inside the virtual cyclone. In combination with the experimental test, this study will reveal both the fluid flow and solid flow features in the virtual cyclone, and address the effects of configuration and sampling flow rate on the gas-solid flow. Optimized design and operational parameters will be put forward from the aforementioned analysis. Then, a prototype PM2.5 sampler will be designed, fabricated, and tested. In addition, performance of the prototype PM2.5 sampler for bio-aerosol sampling will be evaluated. Achievements from this study will provide theoretical guidelines for design of virtual cyclone PM2.5 sampler.

英文关键词： aerosol；size-segregated sampling；virtual cyclone；mechanism；performance evaluation