丁酸甲酯在低转速二冲程内燃机中的NO_X燃烧特性

NO_X Burning Characteristics about Methyl Butanoate in Low Speed Two-Stroke Internal Combustion Engine

应用均质压燃反应器模拟生物燃料分子丁酸甲酯在低转速二冲程内燃机转速为55 r/min^85 r/min不同工况下的燃烧情况,计算反应器内NO浓度、NO_2浓度以及N_2O浓度随曲柄转角的变化关系,并且对NO_X的反应过程进行分析。对相关反应机理进行研究,结果表明:NO和NO_2在尾气中的浓度随转速降低而降低;NO浓度在曲柄转角为350°~390°时下降的原因之一是其转化成了N_2;NO_2浓度在曲柄转角为350°~390°时下降的原因是其转化成了NO;NO_2浓度在曲柄转角为390°~480°时上升是因为其由NO转化而来;N_2O浓度下降大多是因为N_2O转化为N_2的缘故。

The burning situations of methyl butanoate, as biofuel, are simulated in a low-speed two-stroke combustion engine which runs under different conditions from 55 r/min to 85 r/min by applying homogeneous charge compression ignition reactor The mole fraction of NO, NO： and N：O differing with the crank rotation angle is calculated, and the reaction process of NOx is analyzed. According to the study of the relevant reaction mechanism, the results show that the lower the revolution is, the lower the mole fraction NO and NO2 in emission is. During the period of 350°-390° crank rotation angle, one of the reasons about the mole fraction of NO declining is its transition to N2. For the dropping mole fraction NO2, during the same crank rotation angle, its transition to NO couM explain. The rising mole fraction NO2, during 390°~480° crank rotation angle, is clue to its transition of NO. The mole fraction N2O lowering is the reaction that most N2O transited to N2.