生物柴油-生物油乳化油的燃烧排放特性

Combustion and Emission Characteristics of Emulsions From Biodiesel and Bio-Oil

在一台未作改动的直喷式柴油机上研究了生物油质量分数分别为10%和20%的生物柴油生物油乳化油的燃烧与排放特性。结果表明:与生物柴油相比,燃用乳化油时燃烧始点推迟,预混燃烧放热峰值升高,扩散燃烧放热峰值、最高燃烧压力和燃烧温度降低,燃烧持续期缩短,且随着生物油含量增加以上趋势更明显。燃用含10%生物油的乳化油时燃油经济性较生物柴油略低,与0号柴油相当,而燃用含20%生物油的乳化油时燃油经济性则低于生物柴油和0号柴油。乳化油的NO_x排放明显低于生物柴油,而碳烟排放高于生物柴油,但低于0号柴油。

The combustion and emission characteristics of an unmodified direct injection diesel engine operating on two emulsions with 10% and 20% by mass fraction of bio-oil in biodiesel were studied. When the engine operated on the two emulsions, the combustion start point delays, the maximum premixed burning rate increases, the peak values of diffusive burning rate, in-cylinder pressure and combustion temperature decrease, and the combustion duration shortens in comparison with biodiesel. Furthermore, these trends are more remarkable with the increase of bio-oil fraction in the emulsions. The fuel economy of the emulsion with 10% bio-oil content is slightly poorer than that of biodiesel and comparable to that of No. 0 diesel, while the fuel economy of the emulsion with 20% bio-oil content is poorer than those of biodiesel and No. 0 diesel. NOx emissions of the emulsions are obviously lower than those of biodiesel, while smoke emissions of the emulsions are higher than those of biodiesel, but lower than those of No. 0 diesel.