Advanced Aftertreatment System Meeting Future HD CNVII Legislation

<div class="section abstract"><div class="htmlview paragraph">Options for CNVII emission legislation are being widely investigated in a national program organized by China Vehicle Emission Control Center (VECC) since early 2020. It is foreseen that this possibly last legislation in China will have more stringent emission requirements compared to CNVI, including among other changes especially a further reduction of nitrogen oxide (NO_x), inclusion of nitrous oxide (N₂O) and sub-23 nm particle number (PN).</div><div class="htmlview paragraph">This study investigates the technical feasibility to fulfill a CNVII emission legislation scenario, based on a modified CNVI 8 L engine operating under both cold and hot World Harmonized Transient Cycle (WHTC) and Low Load Cycle (LLC). Methods to address the challenges are discussed and validated, including application of a twin dosing system, electric heater, hybrid concepts of combining Copper (Cu-), Iron (Fe-) and Vanadium (V-) SCR technologies, filters with ultra-high filtration efficiency and optimization of engine calibration and urea dosing strategies.</div><div class="htmlview paragraph">Based on the results, an advanced aftertreatment system is then proposed that can meet the requirements of the discussed CNVII scenario.</div></div>