Experimental Investigation on the Effect of Pilot and Post Injection on Engine Performance and Emissions

Diesel engines are facing stringent norms and future survival with its lower availability is one of the biggest concerns for OEMs of heavy duty commercial vehicles. This is leading to uplifting of new, latent and innovative techniques to achieve these norms with best possible BSFC to reduce overall diesel consumption. The prime objective of this study is to identify and explore the latent strength of pre and post injection on engine performance, emissions and oil dilution due to soot. The post injection strategy has the potential to reduce soot with almost same NOx and fuel consumption depending on the delay of post injection and its quantity. It aids to increase the engine out temperatures for assistance of after-treatment devices, thus meeting higher temperature requirements for NOx and PM conversion for stringent norms of BSVI. Post injection was performed by decreasing the main fuel injection duration, so as to keep overall fuelling to same value, thus end of injection was decreased and same NOx level with lower soot in exhaust and oil was observed. On the other hand, pilot injection assisted in lowering the engine noise and from emission point of view, complete soot and NOx trend has been analysed and discussed at key points of WHSC for best BSFC and emission optimization.