正丁醇/柴油PAHs简化机理的构建与仿真

Construction and simulation of n-butanol/diesel PAHs simplified mechanism

为了探讨正丁醇/柴油碳烟的生成途径,分析了正丁醇氧化历程和PAHs(苯、萘、菲、芘)生成路径,保留了与正丁醇/柴油混合燃料PAHs生成密切相关的基元反应,对正丁醇的氧化机理和PAHs的生成机理进行了简化,并加入正庚烷简化机理,构建了由73种组分和89个基元反应的正丁醇/柴油PAHs简化机理.采用简化机理对正丁醇/柴油混合燃料的反应温度等参数进行模拟,结果与反射激波管试验结果一致,验证了简化机理的可行性.在此基础上通过模拟计算,分析了正丁醇/柴油不同掺混比、当量比的PAHs生成量和生成速率随时间变化的规律.结果表明:随着正丁醇掺混比的增加,PAHs生成量和生成速率逐渐减小,峰值出现时刻推迟,总生成量的降幅依次增大;随着当量比的增大,PAHs物质的量峰值增大,峰值出现的时刻推迟.

To explore the formation pathway of n-butanol/diesel soot,the processes of n-butanol oxidation and PAHs of benzene,naphthalene,phenanthrene and pyrene were analyzed,and the basic reaction related to PAHs formation of n-butanol/diesel mixed fuel was retained. The oxidation mechanism of nbutanol and the PAHs mechanism were simplified,and the simplification mechanism of n-heptane was added to establish the simplification mechanism of n-butanol/diesel PAHs with 73 components and 89 elements. The simplified mechanism was used to simulate the reaction parameters of n-butanol/diesel,and the feasibility of the simplified mechanism was verified. Based on the simulation results,the PAHs generation of n-butanol/diesel and the change rule of yield rate with time were analyzed. The results show that the simulation results are consistent with the experimental results of reflected shock tube. With the increasing of n-butanol blending ratio,the PAHs yield and the generation rate are decreased,and the peak time is postponed with decreased total yield. With the increasing of equivalence ratio,the peak time of PAHs matter is increased,while the peak time is delayed.