Diesel injector nozzle optimization for high CNG substitution in a dual-fuel heavy-duty diesel engine

摘要: Abstract Many previous studies have attempted to substitute diesel fuel with compressed natural gas (CNG) in compression-ignition engines, which can substantially reduce CO2 and soot emissions. However, the CNG substitution rate cannot be maximized due several restrictions, most prominently amount of injection. The minimum injection quantity becomes more significant under conditions lower torque or higher rate. In this study, engine experiments were performed at 0, 70, 80% rates various EGR (exhaust recirculation) levels a six-cylinder, 5899-cm3 determine combustion emission characteristics rates. case exhibited highest thermal efficiency largest reduction an elevated noise level 92.3 dB. increase 2.7% 18.7%, respectively. A three-dimensional simulation was optimize injector nozzle hole size rate-of-injection (ROI) for substitution, whereby mass reduced 20% that conventional case. computational result demonstrated 25% smaller diameter (150 μm) advanced ROI 3.4% gross indicated mean effective pressure.