Low NOx Emissions Performance after 800,000 Miles Aging Using CDA and an Electric Heater

Engine and aftertreatment solutions have been identified to meet the upcoming ultra-low NOX regulations on heavy duty vehicles in the United States and Europe. These standards will require changes to current conventional aftertreatment systems for dealing with low exhaust temperature scenarios while increasing the useful life of the engine and aftertreatment system. Previous studies have shown feasibility of meeting the US EPA and California Air Resource Board (CARB) requirements. This work includes a 15L diesel engine equipped with cylinder deactivation (CDA) and an aftertreatment system that was fully DAAAC aged to 800,000 miles. The aftertreatment system includes an e-heater (electric heater), light-off Selective Catalytic Reduction (LO-SCR) followed by a primary aftertreatment system containing a DPF and SCR. To explore the low power potential in combination with CDA and to minimize the fuel and CO2 penalty, the e-heater was set to both a 2.5 and a 5 kW limit, even though it was capable of providing 10 kW. Test cycles included the heavy duty FPT (hot and code), low load cycle, beverage cycle and a stay hot cycle. The study shows how the addition of CDA and an e-heater allow for ultra-low tailpipe NOx emissions even after 800,000 miles of aging.