Fire-induced temperature attenuation under the influence of a single ceiling smoke extraction point in a bifurcated drift

Experimental investigation of temperature decay and maximum smoke temperature beneath an underground mine drift (54 m long, 2.6 m wide, and height of 3.2 m) was carried out to examine the effect of ceiling smoke extraction on fire evolution in an underground mine. A single non-centralized smoke extraction with an extraction flow rate between 0.24-5.42 m3/s was considered, the measured longitudinal velocity was between 0.012-0.220 m/s, and the fire heat release rate (HRR) was between 85-425 KW. The results show that the maximum temperature decreases with the increase in exhaust air volume under the same HRR. Furthermore, an empirical correlation was developed to predict smoke temperature decay beneath the ceiling due to the effect of a single exhaust smoke extraction point. In this study, a comparison of temperature models for different extraction points is further analyzed to investigate the effect of the number of smoke extraction points on the temperature attenuation coefficient. The model developed can be applied to other practical solutions to predict temperature decay beneath the ceiling for axis-symmetric fires in an underground mine drift for a single-point smoke extraction system.