Experimental Study of Oxygen-Enriched Diesel Combustion Using Simulated Exhaust Gas Recirculation

Abstract

The techniques of design of experiments were applied to study the best operational conditions for oxygen-enriched combustion in a single-cylinder direct-injection diesel engine in order to reduce particulate matter (PM) emissions, with minimal deterioration in nitrogen oxide (NOx) emissions, by controlling fuel injection timing, carbon dioxide (CO2) and O2 volume fractions in intake air. The results showed that CO2 addition reduced average combustion temperatures and minimized the rate of increase in NOx emissions observed during oxygen-enriched conditions. It was also observed that oxygen enrichment minimized the deterioration in brake-specific fuel consumption and hydrocarbon and PM emissions that occurred at the highest level of CO2 addition.