The effect of embedded EGR pipe in diesel engine intake port on in-cylinder intake stratification

Abstract

This study focuses on the design of an embedded Exhaust gas recirculation (EGR) pipe within the helical intake port of a diesel engine, adjusting the in-cylinder EGR stratification by changing the structural parameters of the EGR pipe, and examining its impact on engine combustion and emissions. The main focus is on the effect of EGR pipe angle B on in-cylinder EGR stratification. The degree of in-cylinder EGR gas stratification is used to evaluate the EGR stratification gradient and analyze the effects of different swirl ratios and EGR stratification on combustion. The study shows that introducing CO₂ through the EGR pipe can form an ideal radial stratification of rich outer and lean inner layers in the combustion chamber, with a maximum stratification degree of up to 13.2%. Comparative analysis of different swirl ratios and EGR gas introduction reveals that increasing the swirl ratio can significantly reduce soot emissions. Additionally, introducing 10% CO₂ through the embedded EGR pipe can significantly reduce NOx emissions.