Experimental study on particulate and NOx emissions of a diesel engine fueled with ultra low sulfur diesel, RME-diesel blends and PME-diesel blends.
Experimental study on particulate and NOx emissions of a diesel engine fueled with ultra low sulfur diesel, RME-diesel blends and PME-diesel blends.
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DOI：
10.1016/j.scitotenv.2009.10.056
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发表时间：
2010-02
期刊：
影响因子：
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通讯作者：
Lei Zhu;Wu-gao Zhang;W. Liu;Zhen Huang
中科院分区：
文献类型：
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作者：
Lei Zhu;Wu-gao Zhang;W. Liu;Zhen Huang
在康明斯4BTA直喷式柴油机上进行了超低硫柴油和两种不同种类的生物柴油分别掺入5%和20%v/v的基础柴油的增压和中冷试验。试验是在两种稳定转速(1500rpm和2500rpm)下，在五种发动机负荷下进行的。本研究旨在研究生物柴油与超低硫柴油的发动机性能、NOx排放、烟度、PM组成、PM粒度分布，并比较低硫生物柴油与超低硫柴油对微粒排放的影响。结果表明，与基础柴油相比，混合燃料中生物柴油含量的增加对制动比油耗和制动热效率均有一定的提高作用。与基准柴油相比，生物柴油混合燃料的NOx排放量较高。随着生物柴油在混合燃料中比例的增加，烟幕不透明度降低，而总颗粒数浓度增加。同时，超低硫柴油的氮氧化物排放量、烟度和总碳烟浓度均低于基准柴油。此外，随着混合燃料中生物柴油的加入，微粒中SOF和硫酸盐的含量增加，而碳烟的干摩擦系数明显降低。与基础柴油相比，生物柴油提高了柴油的总成核数浓度，而超低硫柴油虽然硫含量较低，但有效地降低了总成核数浓度。这表明，对于超低硫柴油，低硫含量是抑制成核颗粒形成的主要因素，而对于生物柴油，低挥发分、低芳烃含量和高氧含量是改善成核颗粒形成的关键因素。结果表明，较高的NOx排放和总成核数浓度是生物柴油在柴油机上应用的一大障碍。
Ultra low sulfur diesel and two different kinds of biodiesel fuels blended with baseline diesel fuel in 5% and 20% v/v were tested in a Cummins 4BTA direct injection diesel engine, with a turbocharger and an intercooler. Experiments were conducted under five engine loads at two steady speeds (1500rpm and 2500rpm). The study aims at investigating the engine performance, NOxemission, smoke opacity, PM composition, PM size distribution and comparing the impacts of low sulfur content of biodiesel with ULSD on the particulate emission. The results indicate that, compared to base diesel fuel, the increase of biodiesel in blends could cause certain increase in both brake specific fuel consumption and brake thermal efficiency. Compared with baseline diesel fuel, the biodiesel blends bring about more NOxemissions. With the proportion of biodiesel increase in blends, the smoke opacity decreases, while total particle number concentration increases. Meanwhile the ULSD gives lower NOxemissions, smoke opacity and total number concentration than those of baseline diesel fuel. In addition, the percentages of SOF and sulfate in particulates increase with biodiesel in blends, while the dry soot friction decreases obviously. Compared with baseline diesel fuel, the biodiesel blends increase the total nucleation number concentration, while ULSD reduces the total nucleation number concentration effectively, although they all have lower sulfur content. It means that, for ULSD, the lower sulfur content is the dominant factor for suppressing nucleation particles formation, while for biodiesel blends, lower volatile, lower aromatic content and higher oxygen content of biodiesel are key factors for improving the nucleation particles formation. The results demonstrate that the higher NOxemission and total nucleation number concentration are considered as the big obstacles of the application of biodiesel in diesel engine.