PODE/柴油混合燃料对共轨柴油机燃烧与排放特性的影响

Effect of PODE-Diesel Blend Fuel on Combustion and Emission Characteristics of a Common-Rail Diesel Engine

按聚甲氧基二甲醚(PODE)占混合燃料体积分数为10%、20%和30%的掺混比,配制了PODE/柴油混合燃料。在共轨柴油机上研究了PODE掺混比对PODE/柴油混合燃料燃烧和排放特性的影响。结果表明,在额定转速100%负荷时,与柴油相比,不同PODE掺混比PODE/柴油混合燃料的滞燃期缩短,缸内最大爆发压力升高,放热率峰值降低;一氧化碳(CO)体积分数分别降低了13.1%、16.6%和21.3%,未燃碳氢(HC)体积分数分别降低了17.7%、24.1%和26.2%,排气烟度分别降低了29.6%、44.8%和75.8%;但是碳氧化物(NOx)体积分数分别增加了2.0%、7.4%和9.5%;颗粒物数量峰值依次分别增加了16.8%、30.8%和55.1%。在额定转速25%负荷时,不同PODE掺混比PODE/柴油混合燃料与柴油相比,CO体积分数分别降低了12.4%、16.3%和20.8%,HC体积分数分别降低了14.5%、21.6%和24.1%,排气烟度分别降低了28.0%、44.0%和76.0%,但NOx体积分数分别增加了7.7%、10.4%和16.2%。核模态颗粒物数量峰值分别增加了14.3%、26.9%和33.5%;而积聚态颗粒物数量峰值分别降低了15.4%、24.0%和44.5%。

PODE/diesel blended fuel was prepared with the volume fraction of 10%,20% and 30%of PODE in blend fuels.Effect of PODE addition ratio on combustion and emission characteristics were investigated on a common rail diesel engine.Experimental results show that,at rated speed of100%load,compared with diesel fuel,the ignition delay period becomes shortened,the maximum cylinder pressure of PODE/diesel blend fuel is increased,and the peak value of heat release gets decreased.The volume fractions of carbon monoxide（CO）are reduced by 13.1%,16.6% and21.3%,respectively.The volume fractions of unburned hydrocarbons（HC）are decreased by17.7%,24.1% and 26.2%,respectively.Moreover,the exhaust smoke are decreased by 29.6%,44.8% and 75.8%,respectively.Meanwhile,the volume fractions of nitrogen oxides（NOx）are increased by 2.0%,7.4% and 9.5%,respectively.The peak of particulate matter number is increased by 16.8%,30.8%and 55.1%.When engine operation at rated speed with 25%load,the ignition delay period of PODE/diesel blended fuel is shortened,and the maximum cylinder pressure becomes increased.The peak value of heat release is increased,with the volume fraction of CO decreased by 12.4%,16.3% and 20.8%,respectively.The volume fractions of HC are decreased by 14.5%,21.6% and 24.1%,respectively.Exhaust smoke is decreased by 28.0%,44.0% and76.0%,respectively.Yet,the volume fractions of NOxare increased by 7.7%,10.4% and16.2%.The peak values of nuclear mode particles number are increased by 14.3%,26.9% and 33.5%;while the peak values of accumulation mode particles are reduced by 15.4%,24.0%and 44.5%.