An Experimental Study on NOx Reduction Ratio and NH??? slip through the Optimum Injection of Urea-SCR Using Engine Map based Control in light Duty Diesel Engine

In this study, a map- based Dosing Control Unit(DCU) has been developed for effectively reducing NOx emission and minimizing NH??? slip rate in the Urea-SCR system. DCU mapping were based on inlet gas temperature, NOx and O??? concentration in the exhaust for optimizing urea dosing rate. An engine bench test has been performed under ECE-15 mode which is major part of NEDC engine emission test mode. From the results of this work, it can be found that Nox emission could be dramatically reduced by 65% compared to DOC based exhaust system by using the map-based dosing control algorithm developed by this work. It can also found that this map-based dosing control algorithm could keep the averaged NH??? slip below 4ppm for the various operating conditions. As a results, it can be confirmed that optimum injection strategy of urea solution is very effective way for urea-SCR exhaust system to maximize its deNOx performance and meet the future strict NOx emissions regulations