适用于HCCI燃烧研究的甲苯参比燃料化学动力学简化模型

提出了一个适用于均质压燃着火(HCCI)燃烧过程的甲苯参比燃料简化机理模型, 包含70种组分和196个反应. 低温简化机理选用Tanaka等人构建的基础燃料氧化机理中的部分反应, 加入本文构建的甲苯简化子机理中. 高温简化机理主要利用到Patel等人的研究成果, 同时加入关键反应H+O₂+M=O+OH+M]. 简化机理分别对替代混合物中的单组分、双组分、三组分物质进行了着火延迟期的预测计算, 预测结果与实验结果较为吻合. 与HCCI发动机实验的验证表明, 对于各工况下甲苯参比燃料的缸内计算, 该机理的预测能力是令人满意的. 由此可知, 本文提出的TRF简化机理在HCCI燃烧方面的预测性能是可靠的. HCCI发动机工况下最大放热率时刻的敏感性分析表明, 随着压力的升高, C₆H₅与O₂的反应变得更加重要; 甲醛是非常重要的中间产物, 是不应当被忽略的.

Reduced Chemical Kinetic Model of Toluene Reference Fuels for HCCI Combustion

We developed a reduced kinetic model for toluene reference fuel (TRF) including 70 species and 196 reactions for homogeneous charge compression ignition (HCCI) combustion. The low temperature reaction scheme for the TRF was based on the existing low-temperature reaction mechanism developed by Tanaka for primary reference fuel (PRF) oxidation. We added skeletal reactions for PRF oxidation to a reduced toluene sub-mechanism. The high-temperature reaction mechanism was mainly from the previous work of Patel and an important TRF reaction H+O2+M=O+OH+M] was added. Validation of the ignition delay time was performed for single-component, two-component and three-component fuels and the results were satisfactory for HCCI engine conditions. A comparison of various experimental data available in the literature, including shock tube tests and HCCI engine experiments, shows that the present TRF mechanism performs well. A sensitivity analysis at the moment of maximum heat production shows that the reaction of phenol radicals (C6H5) with O2 is more sensitive as the pressure increases. Formaldehyde (HCHO) is a very important intermediate species and should not be neglected.