摘要
The kinematical characteristics and thermophoretic deposition of inhalable particles with the diameters of 0-2.5μm （hereafter referred to as PM2.5） suspended in turbulent air flow in a rectangular duct with temperature distribution were experimentally studied. Particle dynamics analyzer （PDA） was used for the on-line measurement of particle motion and particle concentration distribution in the cross-sections of the duct. The influences of the parameters such as the ratio of the bulk air temperature to the cold wall temperature and the air flow rate in the duct on the kinematical characteristics and the deposition efficiencies of PM2.5 were investigated. The experimental re- sults show that the deposition efficiencies of PM2.5 mainly depend on the temperature difference between the air and the cold wail, wffile the air flow rate and the particlecon^centration almost affect hardly tile clep0si-tion-effi ciency. The radial force thermophoresis to push PM2.5 to the cold wail is found the key factor for PM2.5 deposition.Based on the experimental results, an empirical modified Romay correlation for the calculation of thermophoretic deposition efficiency of PM2.5 is presenlext. The empirical correlation agrees reasonably well with the experimental data.
有 0-2.5 的直径的 inhalable 粒子的 kinematical 特征和 thermophoretic 免职 $μ m (此后叫作 PM2.5 ) 与温度分发在矩形的管在湍动空气流动推迟了试验性地被学习。粒子动力学分析器(PDA ) 在管的剖面图被用于粒子运动和粒子集中分发的联机测量。象体积的比率那样的参数的影响在 kinematical 特征上在管让温度通风到冷壁温度和空气流量， PM2.5 的免职效率被调查。试验性的结果证明 PM2.5 的免职效率主要取决于在空气和冷墙之间的温差，当空气流量和粒子集中几乎几乎不影响免职效率时。把 PM2.5 推到冷墙的径向力 thermophoresis 为 PM2.5 免职被发现关键因素。基于试验性的结果，为 PM2.5 的 thermophoretic 免职效率的计算的实验修改 Romay 关联被介绍。实验关联与试验数据相当同意很好。
基金
the Special Funds for Major State Basic Research Project of China (2002CB211604)
