Real-time Measurement of Oxides of Nitrogen

New emissions regulations and performance requirements imposed on modern diesel engines encourage the development of improved tools for emissions measurements. This study investigated one of the improved tools for NOx emissions measurement. It focused on measurement, comparison and prediction of NOx emissions from heavy-duty diesel engines using two different NOx analyzers. Steady state and transient tests were conducted on six heavy-duty diesel engines and NOx emissions were measured using a conventional Rosemount NOx analyzer and a Cambustion fast response NOx analyzer.Test data obtained from both the analyzers were compared and contrasted. Instantaneous emissions data obtained from the fast NOx analyzer were used to create emissions inventory tables for further analysis. These data were used to deduce power-based fast NOx emissions prediction models, which could predict instantaneous NOx emissions for different engines and cycles.