Performance Assessment of Urea-Selective Catalytic Reduction (SCR) Technology in On-Road 6-Cylinder Heavy-Duty Diesel Engine

Urea- SCR is an essential aftertreatment technique used for reduction of NOx emission in diesel engine to meet BS-VI legislation. This research focuses on performance evaluation of Urea-SCR system in 6-cylinder on road heavy duty diesel engine. The experimentation work is carried out on heavy duty diesel engine in test cell. The influence of ammonia to NOx ratio, space velocity and inlet temperature of SCR were analyzed in terms of NOx conversion efficiency, NOx emission and ammonia (NH3) slip. Thus, it is concluded that DeNOx efficiency of SCR increases with increase in ANR from 0.9 to 1.1. Excellent NOx conversion is observed in high exhaust flow rate. Ammonia slip catalyst shows the better performance at low temperature whereas with rapid increase in temperature of exhaust gases results into ammonia slip. Emission testing gives overall performance of engine and aftertreatment system. All the emissions are within limit, meeting the BS-VI requirements.