Study of EGR and Turbocharger Combinations and Their Influence on Diesel Engine’s Efficiency and Emissions

Abstract

<div class="section abstract"><div class="htmlview paragraph">An experimental study of EGR and turbocharging concepts has been performed on an experimental 2.0-litre 4-cylinder turbocharged Euro6 light-duty diesel engine. The purpose of the study was to investigate the emissions and fuel consumption trade-off for different concept combinations.</div><div class="htmlview paragraph">The impact of low-pressure and high-pressure EGR was studied in terms of engine-out emissions and fuel consumption. Moreover, the influence of single-stage and two-stage turbocharging was investigated in combination with the EGR systems, and how the engine efficiency could be further improved after engine calibration optimization.</div><div class="htmlview paragraph">During low load engine operation where throttling may be required to achieve the desired low-pressure EGR rate, the difference in fuel consumption impact was studied for exhaust throttling and intake throttling, respectively.</div><div class="htmlview paragraph">The cooling impact on high-pressure EGR was compared in terms of emissions and fuel consumption. Finally, an EGR concept for balancing low engine-out emissions in combination with high engine efficiency is proposed.</div></div>