Numerical study of combustion and emission characteristics of a diesel methanol dual fuel (DMDF) engine
Numerical study of combustion and emission characteristics of a diesel methanol dual fuel (DMDF) engine
复制标题
柴油甲醇双燃料（DMDF）发动机燃烧和排放特性的数值研究
DOI：
10.1021/acs.energyfuels.5b00644
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发表时间：
2015
期刊：
影响因子：
5.3
通讯作者：
Chunde Yao
中科院分区：
文献类型：
--
作者：
Ruzhen Zang;Chunde Yao
与大量的试验研究相比，柴油/甲醇双燃料（DMDF）发动机的数值研究非常有限。在这项工作中，一个改进的KIVA-3V程序耦合到CHEMKIN求解器来模拟DMDF发动机的燃烧和排放。首先，一个化学反应机制，包括65个反应和43个物种的开发和验证预混火焰物种分布。其次，在柴油机和DMDF模式下进行了不同负荷下的新发动机实验，以进一步验证本模型。结果表明，该模型能较好地预测发动机在两种工况下的燃烧和排放。最后，对柴油机喷油提前角和废气再循环率进行了参数研究。结果表明，DMDF模式下的滞燃期比柴油机模式下的滞燃期长。通过进气道供应的甲醇在不同的喷射正时显著降低了碳烟排放并略微增加了NOx排放。在两种工况下，碳烟排放都主要形成在碗底、靠近燃烧室中心的碗唇和挤气区。随着EGR率的增加，两种工况下NOx排放均显著降低，碳烟排放均显著增加。DMDF模式下的燃烧特性对EGR比柴油模式下的燃烧特性更敏感。
In comparison to the extensive experimental studies, numerical studies of a diesel/methanol dual fuel (DMDF) engine are very limited. In this work, an improved KIVA-3V code was coupled with the CHEMKIN solver to model combustion and emission of a DMDF engine. First, a chemical reaction mechanism including 65 reactions and 43 species was developed and validated with premixed flame species profiles. Second, new engine experiments at varied loads in both diesel and DMDF modes were performed to further validate the present model. Results show that the model predicts the engine combustion and emission in two modes well. At last, parameter studies on diesel injection timings and exhaust gas recirculation (EGR) rates were performed. Results show that the ignition delay time in DMDF mode is longer than that in diesel mode. Methanol supplied through the intake port significantly reduces soot emissions and slightly increases NOxemissions at different injection timings. In two modes, soot emissions are both formed mainly in the bowl bottom, bowl lip near the combustion chamber center, and squish area. With the increasing EGR rate, NOxemissions are reduced significantly and soot emissions increase significantly in two modes. Combustion characteristics in DMDF mode are more sensitive to EGR than in diesel mode.