在一台单缸柴油机上，以柴油为基准，掺入一定比例汽油和正丁醇组成柴油/汽油、柴油/正丁醇和柴油/汽油/正丁醇混合燃料，研究了较高 EGR 率下喷射时刻和喷射压力对于混合燃料低温燃烧特性和排放特性的影响。结果表明，在柴油中掺混汽油能够改善混合燃料挥发性，降低十六烷值，降低碳烟排放，同时略微提升热效率。掺混正丁醇除了上述优势之外，还能够降低总芳烃含量，且由于正丁醇分子含氧，极大地改善了碳烟排放。在较高 EGR率下，适当提前喷射时刻和提高喷射压力有助于降低碳烟、CO和THC排放，并能提高指示热效率。最大压升率是限制混合燃料喷射时刻进一步提前的主要因素。提高喷射压力对于高挥发性柴油混合燃料油气混合效果的改善作用比柴油弱。%The effects of injection timing and injection pressure on low temperature combustion and emissions were investigated on a single-cylinder diesel engine at high EGR rate. Blended fuels including diesel/gasoline,diesel-butanol and diesel/gasoline-butanol were formulated by blending gasoline and n-butanol with diesel. The results show that the addition of gasoline can improve volatility and reduce the cetane number of diesel,thus reducing soot emission with slightly improved thermal efficiency. In addition,the reduction in aromatic component and the pres-ence of oxygen content of diesel-butanol and diesel/gasoline-butanol blended fuel can further reduce soot emis-sion. Under high EGR condition,the appropriate advance of injection timing and the increase of injection pressure are conducive to the reduction of soot emission and the improvement of indicated thermal efficiency. The further ad-vance of injection timing is restricted by the maximum pressure rise rate. Diesel can be more obviously improved by increasing injection pressure than blended fuels with high volatility.
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