Assessment of pollutants emission and aftertreatment efficiency in a GTDi engine including cooled LP-EGR system under different steady-state operating conditions

This work has been performed in a 4-cylinder, turbocharged, direct-injection gasoline engine with 2.0 L displacement. The equipment used in this study are TSI-EEPS for particle measurement and HORIBA MEXA 1230-PM for soot measurement being HORIBA MEXA 7100-DEGR with a heated line selector the system employed for regulated gaseous emission measurement and aftertreatment evaluation. A reduction around 50% of NOx with an increase of HC and CO emissions was found in medium-load operating points. At full-load conditions, the suppression of fuel enrichment including EGR leads in a drastically reduction in CO maintaining similar HC and NOx emissions. Furthermore, PN and soot emissions also decrease as EGR is included and spark timing advanced in all the tested conditions.