Formation and transformation of volatile nanoparticles from a diesel engine during exhaust dilution  

作　　者：LI XinLing HUANG Zhen 

机构地区：[1]Key Laboratory of Power Machinery and Engineering Education Ministry,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Chinese Science Bulletin》2012年第8期948-954,共7页

基　　金：supported by the National Natural Science Foundation of China (51006067);the Research Fund for the Doctoral Program of Higher Education of China (20070248024)

摘　　要：A classic H 2 SO 4-H 2 O binary homogeneous nucleation model coupled to an aerosol dynamics model,suitable for studying the formation and transformation of volatile nanoparticles (VNPs) during diesel engine exhaust dilution,has been developed.Using the H 2 SO 4-H 2 O binary homogeneous nucleation model,the nucleation ratio and molecular cluster size were calculated.The effect of aerosol dynamic processes on VNP number size distributions was studied.The effects of fuel sulfur content (FSC) and sampling conditions in the laboratory on VNP number size distributions were also calculated.Our simulations demonstrated that nucleation increased the cluster number concentration and that FSC,temperature and humidity significantly affected the nucleation ratio and molecular cluster size.Coagulation promoted the evolution of cluster-particle size distributions from monodisperse to polydisperse.Soot present in the exhaust can suppress the formation of VNPs.FSC and sampling conditions,like the primary dilution temperature,the primary dilution relative humidity,residence time and the primary dilution ratio have significant effects on VNP number size distributions.A classic H2SO4H20 binary homogeneous nucleation model coupled to an aerosol dynamics model, suitable for studying the formation and transformation of volatile nanoparticles （VNPs） during diesel engine exhaust dilution, has been developed. Using the H2SO4H20 binary homogeneous nucleation model, the nucleation ratio and molecular cluster size were calculated. The effect of aerosol dynamic processes on VNP number size distributions was studied. The effects of fuel sulfur content （FSC） and sam pling conditions in the laboratory on VNP number size distributions were also calculated. Our simulations demonstrated that nu cleation increased the cluster number concentration and that FSC, temperature and humidity significantly affected the nucleation ratio and molecular cluster size. Coagulation promoted the evolution of clusterparticle size distributions from monodisperse to polydisperse. Soot present in the exhaust can suppress the formation of VNPs. FSC and sampling conditions, like the primary dilution temperature, the primary dilution relative humidity, residence time and the primary dilution ratio have significant effects on VNP number size distributions.

关 键 词：稀释比例 柴油机排气 纳米粒子 挥发性 大小分布 成核模型 采样条件 相对湿度 

分 类 号：TQ051.13[化学工程] S826.34[农业科学—畜牧学]