Optimization of a Dual-Intake/Exhaust/EGR System with the Exhaust-pulse Ejector for a Heavy-duty Turbocharged Diesel Engine

Various configurations of high-pressure-loop EGR system for a heavy-duty turbocharged diesel engine have been studied through CFD and performance simulation. Dual-EGR piping between the intake- and exhaust-manifolds with the ‘exhaust-pulse ejector’ at the junction of the exhaust manifold were found promising with respect to higher EGR ratio at high load, less pumping loss and higher volumetric efficiency. A reed valve in each EGR passage was effective in that respect. It was also found that combining with venturi tubes or intake-resonance-charging could enhance the above-mentioned effects. Some of these effects have been experimentally proven on a real engine.