Real driving NOx emission characteristics of China Ⅵ heavy-duty diesel vehicles at different altitudes
To understand the NOx emission characteristics of China Ⅵ heavy-duty diesel vehicles at different altitudes,a portable emission measurement system(PEMS)was used to conduct real driving emission tests on ChinaⅥ heavy-duty diesel vehicles in four cities with different altitudes(including Xiangyang,Kunming,Lijiang and Shangri-la).This study showed that with the increase of altitude,NOx emission showed an increasing trend,and the average NOx emission rate under high altitude was 4.65-20.58 times that of the plain,and NOx emission factor was 2.80-13.75 times that of the plain.NOx emission factors of Shangri-la were 1.27-13.75 times higher than those of Xiangyang,Kunming and Lijiang under different load conditions.NOx emission factors of urban road were 1.05-6.49 times higher than those of suburban road and freeway,and the emission factors of urban road in Shangri-la exceeded 400 mg/km.In the interval of Bin 11-Bin 14 and Bin 21-Bin 28,NOx emission rates showed a trend of increases followed by decreases with the increase of VSP.NOx instantaneous emission rate peaked when the vehicles drove from urban road to suburban road and suburban road to freeway at different altitudes.The high NOx emission area was concentrated in the high speed and high torque range.The coefficient of determination between altitude and the average NOx emission factor was 0.86,which showed a fair positive correlation.
NETL
NSTL
万方数据
