Achieving Ultra Low NO<sub>X</sub> Emissions Levels with a 2017 Heavy-Duty On-Highway TC Diesel Engine and an Advanced Technology Emissions System - NO<sub>X</sub> Management Strategies

Abstract

<div class="section abstract"><div class="htmlview paragraph">Recent 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NO<sub>X</sub>) emissions of 0.20 g/bhp-hr. However, CARB has projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NO<sub>X</sub> emissions. The California Air Resources Board (ARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NO<sub>X</sub> emissions. This paper details engine and aftertreatment NO<sub>X</sub> management requirements and model based control considerations for achieving Ultra-Low NO<sub>X</sub> (ULN) levels with a heavy-duty diesel engine. Data are presented for several Advanced Technology aftertreatment solutions and the integration of these solutions with the engine calibration. Further development is necessary for optimizing vocational test cycle emissions, but the results presented here demonstrate a potential pathway to achieving ultra-low NO<sub>X</sub> emissions on future heavy duty vehicles.</div></div>