Experimental investigation of soot and radiation characteristics in ethylene/propane buoyant diffusion flames

Author：Yan, wenbin, Chen, xiao., Lu, shouxiang.

Journal：Fire Safety Journal

DOI:  10.1016/j.firesaf.2022.103692

Keywords: laser-induced, incandescence, volume fraction measurements, burning rate, smoke-point, extinction, fuel, jet, diagnostics, propane, methane

Abstract: 

Experimental study was carried out on the soot and radiation characteristics of ethylene/propane buoyant diffusion flames. Characteristics reported include flame natural luminosity, average soot distribution, maximum soot volume fraction, probability density function, soot yield, radiation flux and flame radiation fraction. Results showed that for a constant burning rate of 1.0 kW, different soot and radiation levels of flames produced can be achieved by adjusting gas composition of fuel mixtures. Propane exhibited a synergistic effect on the soot for-mation, resulting in nonlinear relationship between the maximum soot volume fractions and blending ratios. Based on the analysis of characteristic lengths and characteristic mixture fractions, a correlation of characteristic soot volume fraction with blending ratio was proposed to predict the maximum soot volume fraction of buoyant diffusion flames. The skewed distribution of probability density function elucidates differences in the effect of blending ratio on soot intermittence in the flames. Flame radiation fraction was proportional related to maximum soot volume fraction and linear correlated with soot yield. The analysis provided new comprehensive under-standing of relationship between soot formation and fuel mixture, and could further apply to establish flame radiation equivalence principles of real fire emulation in fire research, fire safety testing and fire-fighting training.