Prediction of combustion and exhaust emissions of a CI engine fueled with diesel-biodiesel blends with different EGR rates

In this paper, the effects of diesel-biodiesel blends with different exhaust gas recirculation (EGR) rates on cylinder pressure, cylinder temperature, brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE) of diesel engines are investigated. The emissions of nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbon (HC), and soot are also predicted to some extent. In this paper, a 3D-computational fluid dynamics (CFD) model of the in-cylinder combustion of a diesel engine is developed using the simulation software CONVERGE combined with an improved kinetic mechanism. A series of sub-models including the combustion, injection, and emission models are selected and presented, and the model's accuracy is verified based on experimental results. The results show that the cylinder pressure and in-cylinder temperature show a decreasing trend with an increasing EGR rate. In addition, BSFC increases with increasing EGR rate, and BTE decreases accordingly. When the EGR rate increased, the emission of NOx decreased significantly, and the higher the EGR rate, the more obvious the decrease. The emission of soot, HC, and CO tended to increase with the increase of the EGR rate.

Automated summary

This paper investigates the effects of diesel-biodiesel blends with different exhaust gas recirculation (EGR) rates on the performance and emissions of diesel engines. A 3D-computational fluid dynamics (CFD) model is developed to analyze the in-cylinder combustion process. The results show that increasing the EGR rate leads to decreased cylinder pressure and temperature, increased fuel consumption, decreased thermal efficiency, reduced NOx emissions, and increased soot, HC, and CO emissions.