암모니아 및 유속분포가 대형 디젤 엔진에 장착된 요소분사 SCR촉매의 deNOx 성능에 미치는 영향

Abstract

Urea-SCR, the selective catalytic reduction using urea as reducing agent, has been investigated for about 10 years in detail and today is a well established technique for DeNOx of stationary diesel engines. In the case of the SCR-catalyst a non-uniform velocity and NH₃ profile will cause an inhomogeneous conversion of the reducing agent ammonia, resulting in a local breakthrough of ammonia or increasing NOx emissions. Therefore, this work investigates the effect of flow and NH₃ non-uniformities on the DeNOx performance and NH₃ slip in a Urea-SCR exhaust system. From the results of this study, it is found that flow and ammonia distribution within SCR monolith is strongly related with DeNOx performance of SCR catalyst. It is also found that multi-hole injector shows better ammonia uniformity at the face of SCR monolith face than one hole injector.