轻烃燃气着火延迟特性研究  

Study on ignition delay characteristics of mixed air light hydrocarbon gas

作　　者：樊玉光[1] 敖一龙 吴松 党文波 王嘉乐 牛斌 FAN Yuguang;AO Yilong;WU Song;DANG Wenbo;WANG Jiale;NIU Bin(School of Mechanical Engineering,Xi′an Shiyou University,Xi′an 710065,China)

机构地区：[1]西安石油大学机械工程学院,陕西西安710065

出　　处：《热科学与技术》2022年第6期580-587,共8页Journal of Thermal Science and Technology

基　　金：陕西省教育厅科研计划资助项目(21JK0838);西安石油大学研究生创新与实践能力培养计划资助项目(YCS20213178).

摘　　要：轻烃燃气是一种新型燃气,产地不同会造成主要成分戊烷异构体含量不同。着火延迟时间是描述燃烧特性的重要参数也是验证动力学机理的重要依据,使用CHEMKIN PRO模拟研究温度1000~1800K、压力(1~20)×1.01325×10^(5)Pa、当量比0.5~2.0内正戊烷异戊烷不同掺混比对着火延迟时间的影响,采用生成速率分析法(ROP)和敏感性分析法探究正戊烷异戊烷掺混比对着火延迟时间的影响机理。结果表明:温度增加会减小着火延迟时间;在研究压力范围内,掺混比影响着火延迟时间趋势较为复杂;从贫燃料区至富燃料区,当量比增加会减小着火延迟时间。异构体中随着正戊烷含量减小着火延迟时间增加,掺混比的影响随着温度、压力增加而减小;OH是戊烷反应消耗脱氢的主要自由基,正戊烷易与OH、HO_(2)反应脱氢,异戊烷易与H、O反应脱氢,当正戊烷含量减少时,OH和HO_(2)消耗减少、H和O消耗增加;反应过程中的主要自由基R(C5H11)基和QO(C5H10O)基含量随着正戊烷含量减小而减小;温度为1000K时,正戊烷敏感性系数最大的反应促进着火减小着火延迟时间,掺混异戊烷后敏感性系数最大的反应抑制着火增加着火延迟时间,当温度为1800 K时,敏感性系数最大的反应均为R1,其他反应敏感性系数相对较小,掺混比对着火延迟时间的影响较小。Light hydrocarbon gas is a new type of gas.Different producing areas will lead to different content of pentane isomers.Ignition delay time is not only an important parameter to describe combustion characteristics,but also an important basis to verify the kinetic mechanism.CHEMKIN PRO was used to simulate the influence of n-pentane isopentane mixing ratio on ignition delay time in the range of equivalence ratio 0.5-2.0 at the temperature of 1000-1800 K,pressure of 1-20 atm,and the influence mechanism was studied by rate of production(ROP)and sensitivity analysis.The results show that the ignition delay time decreases with the increase of temperature.In the pressure range studied,the influence of mixing ratio on ignition delay time is complex.From lean fuel area to rich fuel area,the increase of equivalence ratio will reduce the ignition delay time.With the decrease of n-pentane content,the ignition delay time increases,and the effect of mixing ratio decreases with the increase of temperature and pressure.OH is the main free radical for dehydrogenation consumed by pentane reaction.N-pentane is easy to dehydrogenate with OH and HO2,and isopentane is easy to dehydrogenate with H and O.When the content of n-pentane decreases,the consumption of OH and HO2decreases and the consumption of H and O increases.The contents of R(C5H11)and QO(C5H10O)radicals decrease with the decrease of n-pentane.When the temperature is 1000 K,the reaction with the largest sensitivity coefficient of n-pentane promotes ignition and reduces the ignition delay time.After mixing isopentane,the reaction with the largest sensitivity coefficient inhibits ignition and increases the ignition delay time.When the temperature is 1800 K,the reaction with the largest sensitivity coefficient is R1.The sensitivity coefficients of other reactions are relatively small,and the mixing ratio has little effect on the ignition delay time.

关 键 词：着火延迟时间 戊烷异构体 轻烃燃气仿体 

分 类 号：TK16[动力工程及工程热物理—热能工程]