作　　者： ; ; ; ; (满兴家）;

机构地区： 西安交通大学能源与动力工程学院动力工程多相流国家重点实验室

出　　处： 《内燃机学报》 2013年第6期489-494,共6页

摘　　要： 利用激波管试验平台和Chemkin软件对二甲醚/正丁烷混合燃料在不同掺混比、不同温度和压力下的着火延迟期进行了试验测量和化学反应动力学分析.基于试验数据,提出了一个新的化学反应机理New Mech C5,能够很好地预测正丁烷、二甲醚及其混合物的着火延迟期.结果表明,随着混合气中二甲醚掺混比例的增加,二甲醚/正丁烷的着火延迟期缩短,这主要是二甲醚的加入导致着火过程中自由基池浓度的增加.敏感性分析发现,在高温试验条件下,影响着火延迟期的主要反应为小分子自由基反应.混合燃料中二甲醚比例增大时,无论是二甲醚还是正丁烷的第一步脱氢反应比例均降低,单分子分解反应比例增大. Ignition delay times of dimethyl ether （DME） and n-butane blends were measured by using shock tube at different dimethyl ether blending ratios, temperatures and pressures. Mechanism validations were made using different chemical kinetic models. A new C5 chemical kinetic model with DME sub- model was proposed and it can well predict the experimental ignition delay times of pure n-butane, DME and their blends. Results show that increasing pressure can promote the ignition delay time. Ignition delay time decreases with increasing dimethyl ether blending ratio, and this was interpreted by the analysis of H and OH radical behaviors. Sensitivity analysis and reaction pathway show that, at high temperature, the H-abstraction reactions play a dominant role in the consumption of fuel compared to the unimolecular de- composition reactions. At high temperature, with the increase of DME blending ratio, the branching ra- tios of H-abstraction on fuel （DME and n-butane） consumption are decreased and those of unimolecular decomposition are increased.

关 键 词： 二甲醚 正丁烷 激波管 着火延迟 化学反应动力学

领　　域： [化学工程]