Evaluation of SCR System in Heavy-Duty Diesel Engine

The selective catalytic reduction system has been known well so far in the reduction of NO_x emission in diesel vehicles. On the other hand ammonia slip from SCR reactors must be avoided in the process of catalytic conversion. This research focused to investigate optimal urea injection conditions for urea-SCR system using visualization techniques and evaluate the performance of urea-SCR system in a heavy-duty diesel engine. The parametric study was made on gas temperatures, SVs (space velocity) and ARs (aspect ratio). The urea injector was located at the opposite direction of exhaust gases emitted to an exhaust duct. An optimal quantity of urea and conversion efficient at each mode of ND-13 mode was estimated. Furthermore, NO_x emission and applied amounts of urea was investigated with respect to driving modes under the condition of with/without SCR, This research may provide fundamentals for the practical use of urea-SCR in future.