Study On Emissions Purification Of Diesel/Methanol Compound Combustion

Diesel Methanol Compound Combustion (DMCC) is a new kind of combustion theory which has been conceived on account of the technology background and energy sources condition of China. DMCC, realized by inlet injection of methanol, direct cylinder inside injection of diesel, and precise ratio control of the fuels supplied, makes methanol used efficiently in compression-ignition engine.Research has shown that having succeeded in reducing the temperature of exhaust gas and purifying the emissions of NOx and smoke significantly, DMCC brings the increase of the emissions of HC and CO simultaneously, which are easy to be eliminated by oxidation catalytic converter.A typical engine speed of 1800r/min has been chosen for load characteristic research in order to find improvement approaches to emissions purification of DMCC further. Based on the both diesel oil, standard diesel oil and the marketing diesel oil, with different fuel properties between each other, four experimental models which are the original model for pure diesel, the model of DMCC, the model of DMCC with A oxidation catalytic converter and the model of DMCC with B oxidation catalytic converter were studied.The results showed that for the model of DMCC, the temperature of exhaust gas when combusting standard diesel oil is higher than that of using marketing oil as the engine fuels, so are the emissions of NOx and HC, and the higher the load is, the larger the differences in emissions between each other are. However, the emissions of CO and soot has a contrary situation, and the differences between emissions increased with load decrease; Experiments also found that compared with A catalytic converter, B catalytic converter has stronger low-temperature oxidation, lower ignition temperature (Torque 90 N ? m), higher catalytic conversion efficiency; the catalytic conversion efficiency of both catalysts drops with the number of sulfur content increase; Each catalyst has its sensitivity to sulfur respectively, B catalyst can keep a high level of catalytic effect no matter what the sulfur content of diesel oil is, which can be proved by the catalytic conversion efficiency of HC and CO at 80% and 95%.The matching mode of DMCC can reduce the fuel consumption rate comprehensively. If economic benefit permits, in order to save fuel, increase the rate of alternative fuel-efficient as high as possible. Under the mode of DMCC, the fuel consumption rate is lower while the standard diesel oil is used.