调合生物柴油发动机颗粒物氧化特性研究

发布时间：2018-03-29 15:29

  本文选题：生物柴油　切入点：颗粒物　出处：《广西大学学报(自然科学版)》2016年06期

【摘要】：为研究生物柴油对柴油机排放颗粒氧化特性的影响,利用MOUDI采样器采集不同燃料的排气颗粒物,分别借助透射电镜(TEM)、热重分析仪(TGA)研究颗粒物微观形貌及氧化特性,再利用高倍透射电镜(HRTEM)分析氧化过程中颗粒物微观结构的变化。结果表明:相比于纯柴油,燃用B20燃料(0#柴油掺混20%生物柴油)后,排气颗粒整体尺寸减小且局部重叠和堆积效应减弱,初始粒子粒径增加,全负荷工况下,B0、B20的初始粒子平均粒径分别为32.08 nm、43.42 nm;随着生物柴油掺混比增加,颗粒物起燃温度及最大氧化速率温度依次降低,B0、B5、B10、B20对应的最大氧化速率温度分别为605℃、572℃、524℃、507℃,但B20颗粒物氧化速率峰值较B0增加了约35%,表明B20颗粒物氧化速度加快;颗粒物氧化后的微观结构变化表明,掺烧生物柴油,颗粒物多核结构增多,内核尺寸约为5 nm,多核颗粒内核的氧化活性高于外壳且氧化过程中出现中空胶囊状结构,掺烧生物柴油使颗粒物氧化活性增加。
[Abstract]:In order to study the effect of biodiesel on the oxidation characteristics of diesel engine exhaust particles, MOUDI sampler was used to collect exhaust particles from different fuels. The microscopic morphology and oxidation characteristics of particulate matter were studied by means of transmission electron microscope (TEM) and thermogravimetric analysis (TGA). The microstructure of particulate matter during oxidation was analyzed by high power transmission electron microscope (HRTEM). The results showed that compared with pure diesel fuel, 20% biodiesel was blended with B20 fuel. The overall size of exhaust particles decreased and the local overlap and stacking effect weakened, and the initial particle size increased. The average initial particle size of B0 / B20 was 32.08 nm ~ 43.42 nm under full load condition, respectively, with the increase of the blending ratio of biodiesel, The initial combustion temperature and the maximum oxidation rate temperature of particles decreased in turn. The corresponding maximum oxidation rate temperatures of B _ (0) B _ (5) B _ (5) B _ (10) B _ (10) B _ (20) were 605 鈩，

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