A Study on Emissions Improvement of a Diesel Engine Equipped with a Mechanical Supercharger for Future Emissions Regulation

Abstract

The characteristics of diesel engine equipped with mechanical supercharger had been researched. Mechanical supercharger had good supercharging property on a low airflow condition and a transient response. The OCE (Off-Cycle Emission) regulation is introduced by the next emission regulation, and the NOx emission must reduce even in the full load condition. Probably most engines use the after-treatment device for the NOx reduction. From the simulation study, a possibility to meet the next regulation without NOx after-treatment device was found by using mechanical supercharger and turbocharger. A multi-cylinder engine was used for verification of the simulation. The results showed that potential of meeting next emission regulation without after-treatment device. However there was the issue of durability that caused by higher EGR rate.