An Experimental Study On The Combustion And Emission Of 2-methylfuran Under LTC Mode In A Diesel Engine

With the development of industrialization,people rely too much on fossil fuel consumption to provide energy,resulting in a serious energy crisis and environmental pollution.Therefore,it is important to search for sustainable and clean energy sources in order to reduce the dependency on fossil fuels and lower the emissions of pollutants.2-Methylfurane(MF),which showing good adaptability to the engine has been widely studied by researchers at home and abroad because of its similar properties with gasoline and large-scale preparation from fructose,glucose,cellulose and other biomass.The low temperature combustion(LTC)of diesel engines has been extensively studied in recent years due to its great potential in reducing harmful emissions and combustion noise.The experiments were carried out on a direct-injection compression-ignition diesel engine fueled with diesel fuel and diesel-2-dimethylfuran(MF)blends.The blended fuels contain 10%,20%,30% by mass of MF,referred as M0,M10,M20 and M30.First,study the effects of different exhaust gas recirculation(EGR)rate and fuel characteristics on low temperature combustion and emissions.And then research the effect of single injection strategy(main spray time),two injection strategies(pilotmain strategy and main-post strategy),three injection strategies(pilot-main-post strategy)on low temperature combustion and emissions of MF-diesel mixed fuel under the fixed EGR rate.The results showed that the addition of MF can reduce the cetane number of mixed fuel,prolong the ignition delay,promote the premixed combustion process and improve the thermal efficiency.At the same time,the maximum pressure rise rate(MPRR)increased due to the oxygen content of the MF molecule which shortening the combustion duration.The emission of soot,1,3-butadiene and benzene significantly reduced but NOx emissions increased.The particle size distribution move to the large particle size,the number of small particles increased and the number of large particles decreased,the average particle size increased.The NOx emission can be reduced effectively on large EGR rate and appropriate early spray time can improve the brake thermal efficiency(BTE)effectively,but the maximum pressure rise rate is the key factors to limit the further advance of main spray time.It is effective to reduce the maximum pressure rise rate,improve the brake thermal efficiency and reduce the emission of NOx and 1,3-butadiene,but the soot emission increased at small pilot-spray angle.The HC and CO emissions increased significantly with large pilot-spray angle.With the advance of the pre-spray time,the number of nuclear particles increased and the number of accumulation particles decreased.Therefore,it should be taken into account of both economic and emission to refinement pilot-spray parameters for different proportions of mixed fuel.In main-post spray strategy,the post-spray angle has little effect on main combustion.The smaller postspray angle is favorable for reducing maximum pressure rise rate,increasing brake thermal efficiency,reducing soot emissions,but increasing the emissions of NOx and acetaldehyde.Pilot-main-post spray injection strategy is beneficial to reduce NOx and soot emissions,but its thermal efficiency is significantly reduced.