直喷式柴油机燃用脂肪酸甲酯的排放特性

Study on emission characteristics of direct injection diesel engine fueled with fatty acid methyl ester

脂肪酸甲酯是由生物脂肪经过酯化反应得到的脂肪酸单酯,具有良好的燃料品质和环境友好性,是生物柴油众多种类中的一种。以纯矿物柴油、脂肪酸甲酯、含30%脂肪酸甲酯与70%柴油的混合燃料和含50%脂肪酸甲酯与50%柴油的混合燃料为燃料,在四缸涡轮增压直喷式柴油机上进行的性能对比实验,表明柴油机燃用脂肪酸甲酯能够保持其动力性和燃料经济性,可以显著降低HC和碳烟排放,但会增加CO和NOx排放。脂肪酸甲酯可以作为柴油机的代用燃料进行推广。

This paper aims to report the authors＇ study of the fatty acid methyl ester consisting of plant oil or animal fat in hope to improve the effectiveness and profitability of its practical application. As is known, the fatty acid methyl ester is a kind of bio-diesel that is likely to be used as fuel of diesel engine with the environment-friendly properties. The present paper has compared the properties of fatty acid methyl ester and diesel oil by conducting experiments on a fourcylinder turbo-charge direct injection diesel engine at a compression ratio of 18 and rated power of 76kW at 3800r/min. When the engine is fueled with diesel oil, fatty acid methyl ester, the blended fuel consisting of fatty acid methyl ester and diesel at a ratio of 30% to 70% and 50% to 50% in weight under two working conditions. That is to say, let the engine work at its full load at the speed of 1800r/min and 2200r/min, and watch how about the engine performs its duty. While testing such behaviors as power, energy, consumption, exhaust emission of HC, CO, NOx and smoke, we can find that the power and fuel consumption performance of the engine are equivalent with the HC emission of the engine obviously decreased but the CO emission of engine appreciably increased. At the same time, the NOx can be found remarkably increased when it fuels with fatty acid methyl ester. Further comparing the blended fuel with burning petroleum diesel under the two test conditions, it can be detected that the smoke are lower in conditions of full load at 1800r/min and 2200r/min and free accelerating. Thus, the experimental results show that fatty acid methyl ester can be used as an alternative to diesel oil with good performance of diesel engine and perhaps economic benefits.