Numerical Modeling of Soot and NOx Emissions of a Diesel/Methanol Dual Fuel Engine

In this work, a modeling study was carried out using the KIVA-3V code with the Zeldovich thermal NOx model, the improved soot formation model and the combustion model for a diesel/methanol dual fuel engine. The effects of ratios (10%,20% and 30%) of methanol substitution for diesel fuel on soot and NOx emission characteristics were investigated. Good agreements between predictions and measurements of engine out NOx and soot emissions were achieved. The present computations confirm that methanol allows soot reduction with a little NOx penalty except heavy and full load. With increasing methanol ratio, soot emission decrease markedly while NOx emissions have some increase. At 75% load, the engine-out soot emissions decrease by 66.4% while the engine out NOx emissions increase by 21.5% for 30% methanol, when compared to diesel fuel.