대형 디젤엔진용 Urea-SCR 시스템의 NH3 슬립 억제를 위한 최적 인젝터의 형상 및 위치에 관한 수치적 연구

Abstract

In the past few years, Considerable efforts have been directed towards the further development of urea-SCR (selective catalytic reduction) technique for diesel-driven vehicle. Although urea possesses considerable advantages over ammonia in terms of toxicity and handling, its necessary decomposition into ammonia and carbon dioxide complicates the DeNOx process. Hence the keys to implementation of SCR technology is speeding up thermolysis, good mixing of ammonia and gas and reducing NH₃ slip. In this context, this study performed three-dimensional numerical simulation of urea injection of heavy-duty diesel engine under various conditions of injection pressure, location and injector hole number. The results of this study show some guidelines about the optimum locations and shape of urea injector for reducing NH₃ slip and improving DeNOx performance.