论文标题:降低SOFIM柴油机排放的理论分析与试验研究
Theoretical Analysis and Experimental Research on Decreasing Emissions of SOFIM Diesel Engine
论文作者 苟菁
论文导师 王忠,论文学位 硕士,论文专业 动力机械及工程
论文单位 江苏大学,点击次数 113,论文页数 68页File Size2942k
2005-04-01论文网 http://www.lw23.com/lunwen_72523612/ 柴油机;优化匹配;试验研究
diesel engine; optimization matching; experimental research
柴油机以较高的热效率及良好的可靠性,广泛应用于交通工程机械领域。随着世界范围内汽车排放法规的日益严格,柴油机排放问题更显突出。 本文采用广安—角田的油滴蒸发燃烧模型,并根据Zeldovich-NO的生成机理,以SOFIM柴油机的结构参数为依据,开发了针对该柴油机的NO_x计算模拟软件,验证了该软件对NO_x排放的预测能力。 本文在不改动SOFIM柴油机主要结构参数的情况下,为降低排放污染物,采用改变外部配件和调整供油系统参数的优化匹配法,并根据单因素轮换法的试验设计理论进行了柴油机优化匹配试验研究。选用增压器、喷油器、喷油泵以及供油提前角作为匹配因素,按照一定的轮换顺序,提出了降低柴油机排放污染物的优化匹配试验方案。 本文按照GB17691-2001规定的十三工况测试法,测量了柴油机在不同匹配因素水平下的排放值,分析了排放变化的规律和原因,得出了各种匹配因素的最优解。研究结果表明,选用进气压力和过量空气系数较大的增压器可以改善燃烧过程,降低PM排放,并且保持NO_x排放变化不大;在保持较高的供油压力的条件下,适当增大喷孔孔径,可以降低NO_x排放,并且不会显著增加PM排放;加大喷油泵柱塞直径,能增大喷油压力,改善燃油雾化效果,降低PM排放;适当的调整供油提前角可以使得滞燃期缩短,最高燃烧温度和燃烧爆发压力下降,NO_x排放降低。
Diesel engines are widely used in traffic engineering machine for its high thermal efficiency and reliability. The emission problem of diesel engines is more serious as emission standards around the world become more severe.Hioyadu—Kadota burning model is selected, simulating software is developed which is used to predict NO_x by generating mechanism of Zeldovich-NO and structure parameters of SOFIM diesel engine, and the NOx emission can be predicted by this software.As main structure parameters of SOFIM diesel engine aren"t changed, optimization matching method is used to decrease emissions by changing external attachments and adjusting parameters of fuel supply system. The experimental research on optimization matching is used by the single factor replacement. Turbocharger, nozzle, fuel pump, and fuel delivery advance angle are selected as matching factor. To decrease emissions of the diesel engines an experimental scheme of optimization matching is designed with the replacement sequence method.Emissions have been measured along with GB17691-2001, as the matching factors change. The reasons and regulations relating to emissions have been analyzed, and the optimizing explains also have been searched. It indicates that the turbocharger which increase inlet pressure can decrease PM and restrain NO_x, the nozzle with properly larger diameter can reduce NO_x, and doesn"t increase PM emission evidently, enlarging plunger diameter can increase fuel pressure and decrease PM, moderating fuel delivery advance angle can depress burning temperature and control NO_x.
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