Meeting Future NO X Emissions Over Various Cycles Using a Fuel Burner and Conventional Aftertreatment System
ISSN: 2641-9645, e-ISSN: 2641-9645
Published March 29, 2022 by SAE International in United States
Citation: McCarthy, Jr., J., Matheaus, A., Zavala, B., Sharp, C. et al., "Meeting Future NOX Emissions Over Various Cycles Using a Fuel Burner and Conventional Aftertreatment System," SAE Int. J. Adv. & Curr. Prac. in Mobility 4(6):2220-2234, 2022, https://doi.org/10.4271/2022-01-0539.
The commercial vehicle industry continues to move in the direction of improving brake thermal efficiency while meeting more stringent diesel engine emission requirements. This study focused on demonstrating future emissions by using an exhaust burner upstream of a conventional aftertreatment system. This work highlights system results over the low load cycle (LLC) and many other pertinent cycles (Beverage Cycle, and Stay Hot Cycle, New York Bus Cycle). These efforts complement previous works showing system performance over the Heavy-Duty FTP and World Harmonized Transient Cycle (WHTC). The exhaust burner is used to raise and maintain the Selective Catalytic Reduction (SCR) catalyst at its optimal temperature over these cycles for efficient NOX reduction. This work showed that tailpipe NOX is significantly improved over these cycles with the exhaust burner. In certain cases, the improvements resulted in tailpipe NOX values well below the adopted 2027 LLC NOX standard of 0.05 g/hp-hr, providing significant margin. In fact, near zero NOX was measured on some of these cycles, which goes beyond future regulation requirements. However, burner operation on the tested cycles also resulted in a CO2 increase, indicating that a different burner calibration strategy, or possibly an additional technology, will be needed to achieve lower CO2 emissions.