摘要
为发展微尺度燃烧器并拓展微尺度燃烧理论,对具有外部伴流空气的甲烷非预混微喷管射流火焰燃烧特性进行了实验研究。微喷管采用内径为710μm、425μm及280μm的不锈钢管,通过实验得到了微喷管非预混射流火焰的火焰形态、高度、最小熄灭流速及吹熄极限,并与常规尺度(管内径2 mm)非预混射流火焰进行了对比。研究表明微喷管射流火焰只有层流火焰一种形态;微喷管射流火焰高度主要取决于燃料流速而不受外部伴流速度影响;微喷管射流火焰的吹熄极限随伴流速度先增加后减小,而微射流火焰的最小熄灭流速受伴流空气速度影响较小,随管径减小微喷管射流火焰的可燃范围急剧减小。
The combustion characteristics of methane non-premixed micro-jet-flames in coflow airs were studied experimentally for development of micro-combustor and extension of combustion theory of micro-combustion.Stainless steel tubes with the inner diameters of 710 μm,425 μm and 280 μm were employed in the study.The flame shapes,heights,blow off limits and minimum extinction limits of the micro-jet-flames were obtained from the experiments,and the results were compared with those of an ordinary non-premixed jet-flames（d = 2 mm）.The results show that the micro-jet-flames by those three micro-tubes are in the laminar non-premixed jet-flame regime,the turbulent flame and transient flame were not observed for the non-premixed micro-jet-flames.The flame height of the non-premixed micro-jet-flame is depended on the flow velocity of the fuel and not affected by the velocity of the coflow air.The blow off limit of the micro-jet-flame increases with the velocity of the coflow air firstly and then decreases.The minimum velocity at the flame extinction of the non-premixed jet-flame is not sensitive to the velocity of the coflow air.The flammable region of the non-premixed micro-jet-flame decreases rapidly with the diameter of the micro-tube.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2016年第4期907-911,共5页
Journal of Engineering Thermophysics
基金
国家自然科学基金重点项目(No.51336010)
国家重点基础研究发展计划资助(No.2014CB239601)
