不同稀释条件下湍流扩散射流火焰推举和吹熄特性研究  

Liftoff Height and Blowout Limit of Turbulent Diffusion Jet Flame Diluted by Different Dilution Gases

作　　者：熊世文 王强[1] 吕将 胡隆华[1] Xiong Shiwen;Wang Qiang;LüJiang;Hu Longhua(State Key Laboratory of Fire Science,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,合肥230026

出　　处：《燃烧科学与技术》2024年第2期179-186,共8页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51976051,52225605).

摘　　要：为了安全高效地利用低污染燃烧技术,使用丙烷作为燃料,通过改变稀释气体种类(He/N_(2)/CO_(2))、燃料摩尔分数(0.5~1.0)和射流速度(1.5~55 m/s),采用实验方法研究了不同稀释气体下湍流扩散射流火焰推举高度和吹熄极限.研究表明,对于完全湍流推举火焰,当燃料摩尔分数由1.0下降至0.5时,射流速度每增加1 m/s,火焰推举高度由增加0.18 cm上升至增加0.34 cm(氦气)、0.45 cm(氮气)和0.59 cm(二氧化碳).通过在预混火焰模型中加入燃料摩尔分数这一表征稀释程度的项,修正了Kalghatgi提出的预混火焰预测推举高度模型.同时,当燃料摩尔分数从1.0下降至0.5时,火焰吹熄速度从55 m/s下降至26 m/s(氦气)、16 m/s(氮气)和10.5 m/s(二氧化碳),验证了Kalghatgi提出的预混火焰模型在预测不同稀释气体和稀释度条件下预测吹熄极限的适用性.To utilize clean combustion technologies safely and efficiently,the liftoff height and blow-out limit of diffusion jet flames are studied experimentally by changing the type of dilution gas(He/N_(2)/CO_(2)),mole fraction of fuel(0.5—1.0),and jet velocity(1.5—55 m/s)for propane fuel.The results show that for the fully turbulent flame,when the fuel mole fraction decreases from 1.0 to 0.5,with the jet velocity increasing by 1 m/s,the liftoff height increases from 0.18 cm to 0.34 cm(He),0.45 cm(N_(2)),and 0.59 cm(CO_(2)),respectively.The premixed flame prediction liftoff height model proposed by Kalghatgi is revised by considering the fuel mole fraction as a response to the combustion intensity at the bottom of the flame.At the same time,when the fuel mole fraction decreases from 1.0 to 0.5,the blowout velocity decreases from 55 m/s to 26 m/s(He),16 m/s(N_(2)),and 10.5 m/s(CO_(2)),respectively.The blow-out limit prediction model proposed by Kalghatgi agrees well with the experimental data for three different types of dilution gas.

关 键 词：扩散射流火焰 稀释 推举高度 吹熄速度 

分 类 号：X932[环境科学与工程—安全科学]