柴油机尾气中硝基多环芳烃的排放特征研究

One of the main anthropogenic sources producing nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) is related to diesel engines..Nitro-PAHs are ubiquitous in ambient air and some of them are among the strongest known carcinogens and mutagens with subsequent adverse effects on human health.Therefore,there is an increasing concern about the occurrence of nitro-PAHs in the environment..A diesel particulate filter (DPF) can remove diesel particulate matter or soot from the exhaust gas of a diesel engine and is currently a promising technology of reducing harmful diesel emissions. DPF cleans exhaust gas by forcing the gas to flow through the filter and the filter structure may act as a reaction chamber for the nitration chemistry which will effect the degradation and formation of nitro-PAHs. Although nitro-PAHs of diesel emission with or without DPF have already been studied, information on nitro-PAHs related China's diesel and DPF is still lacking. According to the rapid increase of diesel vehicle population and the tendency of DPF wide usage, it is urgent to develop the research of nitro-PAHs emission. .This work will focus on the diesel engine emission of gas and particle related nitro-PAHs. This will be investigated under the typical engine conditions with or without DPF device. Through the results analysis, get the information of nitro-PAHs emission factors, ratios of gas/particle phases and typical emission spectrum of nitro-PAHs. The related information will be useful to achieve the emission characterization and the effect of DPF and engine conditions on the emission of nitro-PAHs. The results can be used for the estimation of the amount of nitro-PAHs from diesel vehicles and improving national diesel vehicles emission control technologies.

柴油机排放是大气中硝基多环芳烃(nitro-PAHs)的一个重要人为来源，部分具有强致癌性和致突变性，已引起研究者强烈关注。柴油机颗粒物过滤器（DPF）本质上是化学反应器，为尾气中nitro-PAHs的生成和转化提供了新的途径。随着国内柴油车保有量的快速增长和DPF装置的大量采用，对其排放的nitro-PAHs进行深入研究具有重要的意义，但国内目前针对柴油机nitro-PAHs排放的研究非常有限。本课题拟通过发动机台架试验，研究在有无DPF及不同类型的DPF技术条件下，柴油机在典型运行工况时气相及颗粒相nitro-PAHs的排放。通过分析，获得柴油机尾气中nitro-PAHs的排放因子、气固分配比、成分谱等排放特征，揭示DPF技术和发动机工况对柴油机尾气中nitro-PAHs排放的影响规律，并初步估算我国柴油车的气相和颗粒相nitro-PAHs排放量,为柴油车排放控制技术改进提供理论依据。