승용디젤엔진에서 엔진 Map base 제어 로직을 이용한 Urea-SCR 최적 분사에 따른 NOx 저감율과 NH3 슬립에 관한 실험적 연구

Abstract

In this study, a map- based Dosing Control Unit(DCU) has been developed for effectively reducing NOx emission and minimizing NH₃ slip rate in the Urea-SCR system. DCU mapping were based on inlet gas temperature, NOx and O₂ 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 NH₃ 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.