二甲醚对氨着火特性的影响与动力学分析  

Effect of Dimethyl Ether on Ignition Characteristics of Ammonia and Chemical Kinetics

作　　者：金亦凡 马志豪 王鑫 李新 褚祥林 Jin Yifan;Ma Zhihao;Wang Xin;Li Xin;Chu Xianglin(Vehicle and Transportation Engineering College,Henan University of Science and Technology,Luoyang 471003,China)

机构地区：[1]河南科技大学车辆与交通工程学院,河南洛阳471003

出　　处：《内燃机学报》2024年第3期236-244,共9页Transactions of Csice

基　　金：国家自然科学基金资助项目(51906061).

摘　　要：基于激波管测试平台测量了二甲醚对氨气着火延迟期的影响.试验压力为0.14/1.00 MPa,温度为1150~1950 K,当量比为0.5/1.0/2.0,氨/二甲醚掺混比为100/0、95/5、90/10和70/30.试验结果表明:添加二甲醚可以有效缩短氨气的着火延迟期,增加氨气的反应活性.低温、低压条件下,二甲醚对氨气的着火促进作用更强,添加二甲醚导致当量比对氨气着火延迟期的影响减弱.建立了氨气-二甲醚机理以揭示二甲醚对氨气着火的促进作用,并将笔者的着火延迟期数据与部分文献机理进行了验证和对比,本机理能够可靠预测试验结果.通过敏感性分析、反应路径分析及产率分析,解释氨气和二甲醚的相互作用机理.分析表明,二甲醚的促进作用主要是通过加速早期自由基池发展以增加系统反应活性.着火初期二甲醚通过反应HO_(2)+CH_(3)=OH+CH_(3)O产生大量的OH自由基,对氨气消耗并提前启动链反应至关重要.The contribution of dimethyl ether(DME)to the ammonia(NH_(3))ignition delay time was investigated on a reflected shock wave equipment.The experiments were performed at a pressure of 0.14/1.00 MPa,temperature range of 1150—1950 K,equivalence ratio of 0.5/1.0/2.0,and NH_(3)/DME mixing ratios of 100/0,95/5,90/10 and 70/30,respectively.The experimental results show that the addition of DME decreases the ignition delay time and promotes the reactivity of NH_(3).With DME blending,the effect of equivalence ratio on the NH_(3)ignition delay time is decreased,and with an increase in temperature and pressure,the effect of DME on promoting NH_(3)ignition is weakened.An updated mechanism was proposed to quantify DME-promoted NH_(3)ignition.The experimental data was validated with literature mechanisms,and the results were in line with the experimental trends under all conditions.Chemical kinetic analyses were performed to interpret the interactions between DME and NH_(3)for fuel ignition.Numerical analysis indicates that the promotion effect of DME is mainly due to the increase in the rate and concentration of the radical pool,especially the OH radical pool.The large number of OH radicals generated by the reaction HO_(2)+CH_(3)=OH+CH_(3)O during the early oxidation of DME are the key to the consumption of NH_(3)and the early initiation of the chain reaction.

关 键 词：氨 二甲醚 激波管 着火延迟期 化学反应动力学 

分 类 号：TK401[动力工程及工程热物理—动力机械及工程]