OFFICIAL Modelling results The open blasthole was modelled over 16 hours to show the effect of convective cooling from air. A modest reduction in wall temperature resulted with significant upwelling of warm air above the self-heating seam and almost no air movement below it. The air flow and temperature gradients are shown in Figure 10 with notable temperatures reported in Table 3. Figure 14:Plot of temperature over time for an open blast-hole scenario with a heat flux (Q) of 45 W/m2 generated by self-heating coal seam Table 5:Temperature over time at the seam wall (TW), and in the centre of the blasthole (TC), in the open blasthole scenario shown in Figure 11 Time (hours) TWall, TW ( oC) TCentre, TC ( oC) 0 70 20 8 67.1 48.0 16 66.2 47.2 Over 16 hours the open hole wall temperature decreased by approximately 4 oC relative to its initial value, while the air temperature at the center of the hole within the reactive seam increased by approximately 27 oC. When measuring blast-hole temperature prior to loading
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