纳米SiO_(2)和CeO_(2)对柴油/生物柴油掺混燃料燃烧与排放的影响

Effect of nano-SiO_(2) and nano-CeO_(2) composites on combustion and emission properties of diesel engine fueled with diesel/biodiesel blends

文章在ZS1100柴油机上对比研究柴油、B20(20%生物柴油+80%柴油)、B20Si25Ce25(B20+25 mg/kg SiO_(2)+25 mg/kg CeO_(2))、B20Si50Ce50(B20+50 mg/kg SiO_(2)+50 mg/kg CeO_(2))、B20Si100-Ce100(B20+100 mg/kg SiO_(2)+100 mg/kg CeO_(2))的燃烧和排放特性。结果表明:柴油中掺混生物柴油会导致发动机缸压和放热率下降,油耗升高,热效率降低,同时CO、NO_(x)和碳烟排放下降,但会引起HC排放升高;纳米SiO_(2)和CeO_(2)混合添加剂能够优化B20的燃烧,提高缸压和放热率峰值,缩短滞燃期,同时使油耗降低5.9%,热效率提高4.9%;在排放方面,B20中添加纳米添加剂后能使CO、HC、碳烟排放分别降低67.7%、41.9%、66.7%;B20中添加少量的纳米混合添加剂可以使NO_(x)排放降低4.9%,然而随着添加量的增加,NO_(x)排放会有小幅升高,但仍低于柴油的NO_(x)排放量。该文研究表明,纳米SiO_(2)和CeO_(2)混合颗粒是一种良好的生物柴油添加剂,有助于实现柴油机的节能与减排。

This research comparatively investigated the combustion and emission properties of single-cylinder CI engine ZS1100 powered by neat diesel,B20(20%biodiesel+80%diesel),B20 Si25 Ce25(B20+25 mg/kg SiO_(2)+25 mg/kg CeO_(2)),B20 Si50 Ce50(B20+50 mg/kg SiO_(2)+50 mg/kg CeO_(2))and B20 Si100 Ce100(B20+100 mg/kg SiO_(2)+100 mg/kg CeO_(2)).The results show that the blending of biodiesel into neat diesel will decrease in-cylinder pressure and heat release rate,increase the brake specific fuel consumption(BSFC),and reduce the brake thermal efficiency(BTE).Relative to neat diesel,the CI engine fueled with B20 exhibits lower CO,NO_(x) and soot emissions,but it will lead to higher HC emissions.Nano-SiO_(2) and nano-CeO_(2) composite additives can optimize the combustion of B20 to improve in-cylinder pressure and heat release rate,shorten the ignition delay,reduce the BSFC by 5.9%,and increase BTE by 4.9%.As for the emission,the addition of nanocomposites into B20 can reduce CO,HC and soot emissions by 67.7%,41.9%and 66.7%,respectively.Moreover,the addition of low-dose nanocomposites into B20 can reduce NO_(x) emission by 4.9%.The NO_(x) emission will rise slightly as the addition of nanocomposites increases,but it is still lower than the case of neat diesel.In general,nano-SiO_(2) and nano-CeO_(2) composite is a good biodiesel additive,which helps to realize energy saving and emission reduction for CI engines.