甲烷-正庚烷混合物的预混层流火焰研究  

Study on Premixed Laminar Flames of Methane-n-Heptane Mixtures

作　　者：梁俊杰[1,2] 李格升[1,2] 张尊华[1,2] 周梦妮[1,2] Liang Junjie Li Gesheng Zhang Zunhua Zhou Mengni(Key Laboratory of High Performance Ship Technology of Ministry of Education, Wuhan University of Technology, Wuhan 430063, China School of Energy and Power Engineering, Wuhan University of Technology, Wuhan 430063, China)

机构地区：[1]武汉理工大学高性能船舶技术教育部重点实验室,湖北武汉430063 [2]武汉理工大学能源与动力工程学院,湖北武汉430063

出　　处：《内燃机学报》2016年第5期423-430,共8页Transactions of Csice

基　　金：国家自然科学基金资助项目(51479149);交通运输部基础研究资助项目(2015329811130)

摘　　要：利用球形传播火焰试验和一维平面火焰数值模拟对0.1 MPa、393 K条件下甲烷-正庚烷混合物的预混层流燃烧特性进行了研究,其中当量比从0.7到1.5、甲烷含量从0到100%,.结果表明:随着甲烷含量的提高,甲烷-正庚烷混合物的层流燃烧速度和Markstein长度首先基本保持不变,呈现出与正庚烷类似的特性,当甲烷含量达到75%,时,其层流燃烧速度和Markstein长度开始不同于正庚烷,逐渐发生变化.结合层流燃烧速度的敏感性分析,对混合物一维平面火焰中主要自由基的浓度和主要基元反应的反应速率随甲烷含量的变化进行了研究,发现当甲烷含量增至75%,时,主要自由基(·H、·OH和·O)的摩尔分数峰值和基元反应(R1 H+O_2=O+OH、R24 CO+OH=CO_2+H)的反应速率峰值都开始发生变化.Premixed laminar combustion characteristics of methane-n-heptane mixtures under 0.1 MPa at 393 K were investigated via the outwardly expanding spherical flames and the simulation of one-dimensional planar flames. In this study, equivalence ratios and methane contents are 0.7-1.5 and 0-100%, respectively. Results show that when in- creasing the methane content, laminar burning velocities and Markstein lengths of the methane-n-heptane mixtures maintain almost constantly at small methane contents, similar to those of n-heptane. However, when methane con- tent reaches 75%, obvious differences are presented between n-heptane and methane-n-heptane mixtures in laminar burning velocities and Markstein lengths. Variations of the concentrations of the main radicals（. H, ~ OH and ~ O） and the reaction rates of the main elementary reactions （R1 H ＋ 02 = O ＋ OH and R24 CO ＋ OH = CO2 ＋ H） in the planar flames of methane-n-heptane mixtures were analyzed, and it was found that when methane content reaches 75%, the peaks of mole fractions of the main radicals and reaction rates of the main elementary reactions change significantly.

关 键 词：甲烷 正庚烷 球形传播火焰 化学动力学 预混层流燃烧 

分 类 号：TK407.9[动力工程及工程热物理—动力机械及工程]