Characteristics of on-road NO_x emissions from Euro 6 light-duty diesel vehicles using a portable emissions measurement system

摘要

This paper presents the on-road nitrogen oxides (NO_x) emissions measurements from Euro 6 light-duty diesel vehicles using a portable emissions measurement system on the predesigned test routes in the metropolitan area of Seoul, Korea. Six diesel vehicles were tested and the NO_x emissions results were analyzed according to the driving routes, driving conditions, data analysis methods, and ambient temperatures. Total NO_x emissions for route 1, which has higher driving severity than route 2, differed by -4-60% from those for route 2. The NO_x emissions when the air conditioner (AC) was used were higher by 68% and 85%, on average, for routes 1 and 2, respectively, compared to when the AC was not used. The analytical results for NO_x emissions by the moving averaging window method were higher by 2-31% compared to the power binning method. NO_x emissions at lower ambient temperatures (0-5 ℃) were higher by 82-192% compared to those at higher ambient temperatures (15-20 ℃). This result shows that performance improvements of exhaust gas recirculation and the NO_x after-treatment system will be needed at lower ambient temperatures.