中文摘要：

采用管式炉研究了在02／CO2气氛下添加CaCO3对PM25（空气动力学直径小于2．5gm的颗粒物）排放特性的影响．试验采用荷电低压撞击器（ELPI）采集和分析燃烧后的PM2.5．结果表明，添加CaCO3是燃烧过程中影响PM25生成的重要因素．添加CaC03后，生成PM1的数密度和质量浓度均降低，而PM1-2.5的数密度和质量浓度均略有增加，PM25粒径分布均呈双峰分布，峰值点分别出现在0．2gm和2．0μm左右．随着CaCO3添加质量分数的增加，PM25中的S、Pb、Cu、Na和K几种元素的浓度呈下降趋势．

英文摘要：

The influence of CaCO3 additive on the emission characteristics of PM2.5 （particulates with the aerodynamic diameter of less than 2.5 μm）was studied with using a tube furnace. The combustion tests were carried out at 1 123 K under O2/CO2 atmosphere. The PM2.5 generated from coal combustion was collected and analyzed by an electrical low pressure impactor （ELPI）. The results indicate that CaCO3 is an important factor in the formation of PM2.5 during coal combustion under O2/CO2 atmosphere. After CaCO3 is added, the number and mass concentrations of PM1 diminish, while those of PM1-2.5 enhance slightly, the size distributions of PM2.5 are similar, which display two peaks around 0.2 pm and 2.0 μm, respectively. With the increase of the mass fraction of CaCO3 additive, the concentrations of S, Pb, Cu, Na and K decrease.