Attaining improved control over the start of combustion in dual-fuel HCCI engine through the influence of EGR

HCCI engines are advantageous in delivering low NOx emissions but hindered in controlling the auto-ignition, have poor cold-start capability, shorter combustion duration. A computational analysis has been conducted to investigate the influence of EGR on the working of dual-fuel HCCI engine with n-dodecane and ethanol as fuels. ECFM-3Z model is employed for analysis, and it is validated using the existing literature. EGR is a system that involves recirculating the exhaust gases delivered from combustion into the cylinder. The analysis is done for fuel mixture of equivalence ratios φ = 0.55 and φ = 0.65. EGR is varied from 0 to 14% for φ = 0.55 and 0% to 10% for φ = 0.65. The remaining parameters, like injection timing, compression ratio, engine speed, etc., are unchanged. The results acquired from the analysis show a significant influence of EGR on combustion, performance and emissions. The emissions of NOx and soot were reduced, and control over the start of combustion is improved with influence of EGR.