Analysis of actual road emission characteristics of heavy-duty diesel vehicles based on remote monitoring data

LIU Jiaang; LIU Zonghao; YANG Baohua; ZHANG Ni; LIU Shucheng

doi:10.19471/j.cnki.1673-6397.2025.02.011

Abstract：To study the emission characteristics of heavy-duty diesel vehicles under actual road conditions,relevant data is collected based on a remote monitoring cloud platform to analyze the NOx emission characteristics of diesel heavy-duty vehicles under micro driving conditions.Based on the power based window method,the normal and fixed consumption of selective catalytic reduction(SCR)reactants,as well as the actual NOx emission characteristics of heavy-duty diesel vehicles driving on different roads are analyzed.The results indicate that the driving roads of the sample vehicles are mainly urban and suburban areas,with relatively concentrated acceleration and vehicle specific power(VSP)intervals.Under micro driving conditions,within the same speed range,the NOx emission rate is positively correlated with acceleration and VSP.The NOx emission rate during deceleration is significantly lower than that during acceleration.Within different speed ranges,the NOx emission rate shows a trend of first increasing and then decreasing with the increase of acceleration and VSP.Based on the power based window method,among 32 vehicles with normal reactant consumption,there is a significant difference in NOx specific emissions,with 40.6％of heavy-duty diesel vehicles meeting the standard limit of 4 g/(kW·h)for specific emissions.10 vehicles with fixed reactant consumption have NOx specific emissions exceeding the standard limit,with the maximum NOx specific emission being 3.4 times the standard limit.The analysis of the specific emissions of vehicles traveling on different roads shows significant differences in emissions among urban,suburban,and highway conditions,with average NOx specific emissions of 6.08 g/(kW·h),8.06 g/(kW·h),and 3.43 g/(kW·h),respectively.