An Innovative EGR Admission Concept for di Diesel Engine

Exhaust gas recirculation (EGR) is an effective means to reduce NOx emissions in Diesel engines. An innovative concept of EGR admission was developed for diesel engine of heavy-duty application. A 4-cylinder, naturally aspirated, water-cooled engine was selected for experimental investigation. One-dimensional simulation software was used to predict emission and performance parameters. The engine model was initially validated with experimental data and then used for parametric study for EGR. The best EGR flow rates were determined for experimental study, to study the effect of EGR on engine emissions. A significant reduction in emissions of NOx with minimal increase in CO and HC emission was achieved. Based on number of experiments and simulations an innovative EGR system was developed to control flow of hot exhaust back into the intake manifold for NOx reduction. The EGR system works on the digital logic, which control the amount of EGR precisely for different engine operating conditions. To identify and avoid EGR maldistribution is one of challenge in design of EGR system. A simple methodology was derived to identify the EGR mal distribution for individual cylinders. The methodology based on simple experiments and coupling of these results to one-dimensional thermodynamic model. Finally, the EGR system could enable the engine to reduce the NOx emissions up to 54% from base line. Thus by applying innovative concept of Digital EGR, the engine showed potential to meet stringent future emission norms.