Soot loading, temperature and size of single coal particle envelope flames in conventional- and oxy-combustion conditions (O2/N2 and O2/CO2)

Transient model for soot formation during the combustion of single coal particles

“…The simulation conditions are consistent to those used in the experiments conducted by Khatami et al [12] . In the experiments, coal particles were burnt in a drop-tube furnace, and f v was measured by an emission-based pyrometric method.…”

“…5 , the presence of soot also extends the volatile flame period by ∼ 2.6 ms and decreases the temperature at the onset of the third period. The peak f v is in the same order as that measured in the experiments of Khatami et al [12] , as will be shown in Section 3.4 . The results confirm that soot significantly affects the heat transfer between the flame and the coal particle or the environment [8] .…”

“…The deviation is possibly caused by the T f differences and the spherical assumption of the sooting flame used in current study. In fact, soot particles are in favor of locating above the coal particle due to the gravity and convection, making the measured soot amount slightly higher than the prediction with the spherical assumption [12] .…”

“…The comparison between the predicted f v and the measurement data is also shown in Fig. 8 , and the error bars represent the range of uncertainties using different data processing methods [12] . The results show that the predicted f v agrees well in trend with the experimental results, but with some discrepancy in the values.…”

“…Moreover, the interactions between the flame temperature, structure, and soot formation are assessed. To validate the model, the predictions on soot formation and flame temperature are compared with the recent experimental results measured in a drop tube furnace by Khatami et al [12] . Figure 1 schematically depicts the typical temperature and species mass fraction profiles around a coal particle burning in a free, high temperature environment.…”