柴油机排放多环芳香烃与羰基化合物组分特征研究

Composition Characteristics of Polycyclic Aromatic Hydrocarbons(PAHs) and Carbonyl Compounds in Diesel Engine Emissions

使用色谱-质谱联用和高效液相色谱方法,精确定性和定量检测不同工况下柴油机排放的多环芳香烃和羰基化合物,并分析了它们的排放特征。在50%和全负荷时,多环芳香烃的平均比排放量分别为51.68μg/(kW.h)和104.76μg/(kW.h),羰基化合物的平均排放量分别为23.72μg/L和117.84μg/L。多环芳香烃和羰基化合物归一化研究表明:菲、蒽、荧蒽、芘之和占多环芳香烃总量的62%～66%,甲醛、乙醛之和占羰基化合物总量的63%～66%。多环芳香烃及羰基化合物组分在柴油机各工况间有较好的线性相关关系,说明柴油机工况的变化对多环芳香烃和羰基化合物组分特征没有明显影响。

The polycyclic aromatic hydrocarbons （PAHs） and carbonyl compounds in diesel engine emissions at different operation conditions were analyzed by gas chromatogram-mass spectrometry （GC-MS） and high performance liquid chromatography （HPLC） qualitatively and quantitatively. Based on the results, the emission characteristics of PAHs and carbonyl compounds were investigated. The mean specific emissions of PAHs are 51.68μg/（kW.h） at 50%toad and 104.76μg/（kW.h） at full load. The mean emissions of carbonyl compounds are 23.72 μg/L at 50 % load and 117.84 μg/L at full load, respectively. The emissions of PAHs and carbonyl compounds under different exhaust gas recirculation （EGR） rates and boost pressures were normalized. The amount of phenanthrene, anthracene, fluoranthene and pyrene account for 62-66 % of total PAHs and the amount of formaldehyde and acetaldehyde account for 63%-66% of total carbonyl compounds. The good linear relationship of PAHs and carbonyl compounds among various conditions indicates that engine conditions have no significant effect on PAHs and the carbonyl composition characteristics.