Ignition and Combustion of Methanol Premixture in a Dual Fueled Diesel Engine

Abstract

In order to attain a significant improvement of the trade-off between NOx and smoke, combustion tests on methanol premixture were carried out in a dual-fueled diesel engine assisted by gas oil injection The effects of methanol mixture concentration, intake temperature and the EGR rate on ignition and combustion of methanol premixture were investigated respectively as well as the effects of gas oil injection timing and nozzle orifice size on smoke and NOx. It is clarified that it is necessary to control the intake temperature for avoiding the auto-ignition of methanol mixture, and the suitable combination between methanol charge rate, gas oil injection timing, nozzle orifice size, intake temperature and EGR rate is required for each load to obtain a marked improvement of the trade-off.