摘要
为改善甲烷在平板式微型燃烧器内的燃烧特性,对掺氢甲烷的预混合燃烧过程进行二维数值模拟,研究不同掺氢比及不同通道高度下混合燃料的燃烧规律。结果表明,在当量比为0.8的条件下,氢气的掺入具有稳定火焰和提高混合燃料可燃流速的作用;在掺氢比为5%~25%的范围内,随着掺氢比的增大,火焰锋面逐渐前移,掺氢比每增加5%,火焰最高温度平均可升高101 K;反应中OH的摩尔分数将随氢气的增多而升高,但CO2的摩尔分数随掺氢比的增大反而减少,CO2生成率呈现先缓慢升高后急剧下降的趋势。此外,氢气的加入很好地解决了甲烷难以在小于2.5 mm的通道高度内燃烧的缺陷,通道高度从3 mm递减到1 mm,相应的CO2生成率逐渐减少;通道高度为4 mm时,火焰中心温度达到最大的2 260 K,其出口处的CO2摩尔分数低于另外三组通道高度的值。
In order to improve the combustion performance of methane in a micro planar combustor,2D numerical simulation on premixed combustion process of methane with hydrogen addition is conducted,and the combustion characteristics of mixed fuel under different mixing ratio and channel height are studied.The results show that the addition of hydrogen can stabilize the flame and enhance the burning velocity when equivalent ratio is 0.8.When the addition ratio is in the range of 5% to 25%,the flame front gradually moves forward with the increase of the hydrogen mass fraction.The highest temperature of flame can get an average growth of 101 K as the addition ratio is increased by 5%.Along with the increase of the hydrogen mass fraction,the mole fraction of OH raises gradually while the amount of CO2 decreases apparently,and the generation rate of CO2 presents a tendency of rising slowly before it falling sharply.In addition,the addition of hydrogen can solve the question that the methane is difficult to combust inside a channel with the height less than 2.5 mm.When the channel height decreases from 3 mm to 1 mm,the corresponding generation rate of CO2 reduces gradually.The flame center reached the maximum temperature of 2 260 K when the channel height is 4 mm,and the CO2 mole fraction at the exit is lower than that of other three cases.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2015年第18期151-157,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金(50126066
51376082)
中国博士后科学基金(2014M551514)
江苏省基础研究计划(BK20131253)
江苏高校优势学科建设工程
江苏大学高级专业人才科研启动基金(11JDG139)
江苏大学研究生创新计划(1291130027)资助项目
关键词
微型燃烧器
掺氢甲烷
稳定火焰
OH摩尔分数
CO2生成率
通道高度
micro-combustor
hydrogen-enriched methane
flame stabilization
OH mole fraction
CO2 generation rate
channel height
