Investigation of ammonia homogenization and NOx reduction quantity by remodeling urea injector shapes in heavy-duty diesel engines

Gaseous NOx emission is very hazardous for human health and heavy-duty diesel engines contribute 40% of these global highway emissions. Among technologies for reducing emissions, DPF and SCR are most common, and are used in many automotive industries. The honeycomb-shaped catalyst and ammonia gas utilized in these methods can reduce NOx emissions by more than 90%. However, improvement of NOx emission reduction emission is needed. This study investigates two model injectors to optimize spray distribution for improve the NOx conversion quality in the diesel engine, especially a heavy-duty diesel engine, because these engines produce a huge amount of NOx concentration compared to another engines. These investigations also identified the amount of ammonia gas on the catalyst surface by utilizing 19 gas sensors. Comparison between the experiment and simulation shows the ammonia and NOx quantities from the two injector models and elucidates the temperature results for vaporization and saturation quantity, ammonia homogenization distribution, and NOx conversion in the system.