地铁通风系统主风道内可吸入颗粒物沉降和脱附特性研究

So far, there is not a model which can reflect the mechanism of the movement of inhalable particulate in the situation of the main air duct in subway which is large in air flow, flow dimension and high in Reynolds number. Considering the complex factors of main duct : laying underground, the structure and shape of air duct, the direction of air duct, the roughness of its surface, the distribution in aerodynamic diameter of particulate matters, the initial deposition of particulate matters on the wall of ducts etc. Research papers of the affect mechanism of the distribution of inha1able particulate in the main duct of subway was barely published. Fundamental research in this field is still very insufficient. However, in the future, the main duct is likely to be first concerned in the controlling and operating of inha1able particulate, this is the main point of the research. This research will look into the law of distribution, deposition and re-suspension of inha1able particulate in the main duct of Subway Ventilation System combine field experiment, model test and computer simulation. Looking for reasonable designing main ducts of subway and providing theory evidence for the removal of inha1able particulate in main ducts, it is a key and urgently needed science and technology point in the development of economy and society of our country, the achievement of the issue have important theoretical meaning and use value.

目前国内外尚没有一个能够较好地反映地铁主风道这样的大风量、大尺度、高流动雷诺数情况下可吸入颗粒物运动机理的模型。特别是考虑地铁主风道这样的处于地下深处、风道的结构和形状、风道敷设走向、风道表面粗糙度、颗粒的空气动力学直径分布以及管道壁面颗粒物的初始沉积状况等复杂因素，对地铁主风道内可吸入颗粒物分布影响机理方面的研究文献罕有发表，这方面的基础性研究工作还相当匮乏。但未来可能对地铁系统进行可吸入颗粒物控制和处理的最优先考虑的部位就是主风道，这是本项目研究的出发点和落脚点。本研究拟采用将现场试验、模型实验和计算机数值模拟相结合的方法，研究地铁通风系统主风道内可吸入颗粒物的分布、沉降和二次浮升的规律，以期为合理设计地铁主风道以及在主风道内进行可吸入颗粒物的去除提供理论依据和支撑，是我国经济社会发展中迫切需要解决的关键科技问题，课题的研究成果具有较重要的理论意义和实用价值。

本项目主要业研究地铁主风道内可吸入颗粒物沉降和脱附特性。首先，针对多分散颗粒物粒径测量难度大、不易操作等这一系列问题，自主创新的设计出可吸入颗粒物高清电子显微镜计数检测方法。这一具有学科交叉性的创新检测方法采用血细胞计数原理与高清电子显微镜计数高新技术相结合，这种方法既能较准确的检测出颗粒物的数目，又可以直接在高清显示屏上量出颗粒的粒径，解决了可吸入颗粒物沉降和脱附量难以计重称量的难题。其次，现有气溶胶脱附模型和计算公式是基于小尺寸、小粗糙度的管道得出的，难于推广到大粗糙度、大断面尺寸的情况，加之现有气溶胶脱附模型仅针对的单分散可吸入颗粒物在指定的流动形式下脱附的情况过于理想化，与现实场景差别较大，指导意义不强。根据实验结果结合理论分析得出大尺度、大的壁面粗糙度下的颗粒物沉降和脱附机理模型，并通过实验验证了主风道中可吸入颗粒物沉降和脱附运动特性以及机理模型。第三，对地铁主风道中内的可吸入颗粒物沉降和脱附运动进行数值仿真研究，给出了针对这类问题的数值仿真方法。.中国的地铁建设方兴未艾，可吸入颗粒物作为对人体健康潜在影响很大的一类污染物越来越受到公众的关注。本项目将为可吸入颗粒污染在地铁系统内的防治提供理论依据。