Emission characteristics analysis under California low load cycle for a China VI heavy-duty diesel engine

A 6.2 L diesel engine that meets China VI emission standard was selected to run world harmonized transient cycle (WHTC) and California Low Load Cycle (LLC) measure the pollutants. The brake specific under two cycles were compared, nitrogen oxides (NOx) analyzed carefully. results show NOx of LLC this is about 15 times than hot WHTC, 4.7 limitation current standard. low inlet temperature selective catalytic reduction (SCR) predominant reason for high in LLC. SCR lower 200°C accounts 52% total time with an average only 190°C. While WHTC 7% 275°C. efficiency calculated by sensor amounted on upstream downstream 75%, while 98% WHTC. It necessary focus thermal management aftertreatment system performance at temperature.