Continuing Progress Towards 2027 Low NOx Targets – Update on Demonstration Efforts at SwRI
Christopher Sharp, Southwest Research Institute
Following the conclusion of the Stage 3 CARB Low NOX Demonstration program in late 2020, technology demonstration efforts on the Low NOX engine have continued in support of the U.S. EPA’s efforts to develop a national Heavy-duty Low NOX standard to be implemented starting in 2027. These efforts have focused in a number of areas, including improving the performance and robustness of the Low NOX aftertreatment system, continued aging to demonstrate performance at longer useful life intervals (eventually up to 800,000 miles equivalent), examination of performance on real-world duty cycles, and assessment of in-field measurement approaches using both portable emission measurement systems (PEMS) and sensor-based approaches. This presentation will provide an update on those continued development efforts. The most recent performance results and plans for upcoming work will be discussed. System behavior will be examined operating over several real-world duty cycles. Examples of SCR control system performance and system sensors over these real-world cycles will also be examined.