Abstract Experimental study was carried out on the combustion characteristics of buoyant turbulent diffusion propane flame with fuel volume fraction ranging from 0.2 to 1.0 by nitrogen addition. The combustion characteristics reported include total flame length, flame diameter, soot free length fraction (SFLF), axial temperature distribution, maximum axial temperature and flame radiation fraction. Results show that the total flame length and flame diameter are insensitive to nitrogen addition. Soot free length fraction was found to be proportional to ( 1 + S ) 1 S - 0.5 f v , f u e l - 1 . The axial temperature near the burner decreases while increases at higher height with nitrogen addition. The maximum axial temperature increases at first then decreases with nitrogen addition. The different trends in axial temperature characteristics are brought by two competitive effects between cooling effect and declined radiative heat loss due to nitrogen addition. The flame radiation fraction decreases with nitrogen addition due to soot reduction and is found to be proportional to ( 1 + S ) - 0.25 S 0.125 f v , f u e l 0.25 based on theoretical analysis and experimental results. The correlation result is compared to the previous data indicating good applicability.

中文翻译：

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添加氮对浮力湍流扩散火焰燃烧特性影响的实验研究

摘要 对燃料体积分数为0.2～1.0的浮力湍流扩散丙烷火焰通过添加氮气燃烧特性进行了实验研究。报告的燃烧特性包括总火焰长度、火焰直径、无烟灰长度分数 (SFLF)、轴向温度分布、最大轴向温度和火焰辐射分数。结果表明，总火焰长度和火焰直径对氮添加不敏感。发现无烟灰长度分数与 (1+S) 1 S-0.5 fv，fuel-1 成正比。随着氮的加入，燃烧器附近的轴向温度降低，而在较高高度处升高。随着氮的加入，轴向最高温度先升高后降低。轴向温度特性的不同趋势是由冷却效果和因氮添加引起的辐射热损失下降之间的两种竞争效应带来的。由于烟灰减少，火焰辐射分数随着氮的加入而降低，并且基于理论分析和实验结果被发现与 (1 + S ) - 0.25 S 0.125 fv 、燃料 0.25 成正比。将相关结果与之前的数据进行比较，表明适用性良好。