国 六 重 型 柴 油–液 化 天 然 气 车 实 际 道 路排 放 特 性 研 究

A portable emission testing system（PEMS） was used to test the real driving emissions of four typical heavy-duty diesel vehicles and four typical heavy-duty liquefied natural gas（LNG） vehicles respectively. The real driving emission characteristics of NO_x，CO，CO₂，and particulate number（PN） were analyzed by the work-based window method and trip average method. The results indicats that the emission aftertreatment technology can effectively control the NO_x，CO，and PN emission factors of China VI heavy-duty diesel vehicles under real driving conditions. However，the CO emission of LNG vehicles have a risk of exceeding the emission limit，and some LNG vehicles have a phenomenon of over-NO_x-emission. The PN emissions are uncertain，and some LNG vehicles have higher PN emissions. For carbon emissions，the real driving CO₂ emission factors of LNG vehicles are 6%~18% lower than those of diesel vehicles，where the carbon reduction is of a great manifest.