Self-combustion of coal deposit in a goafs area is common phenomenon in underground coal mines. The essence of this phenomenon is slow oxidation of coal leavings caused by air fl ow, which, in conjunction with insufficient heat transfer produces temperature rise above its ignition value. Main problem concerning self combustion phenomenon is proper estimation of the process scale. The most efficient way dealing this problem would be constant monitoring of mine atmosphere composition in selected region located inside goafs zone, but this kind of activity is impossible to realize mainly because of technical constrains. One of the solution assumes constant monitoring of air composition in upper corner, in this case however content of carbon monoxide could indicate already existing fi re in the goafs, not the self heating conditions.

 

 Taking into account above observations, it would be good solution to utilize temperature sensors in longwall’s upper corner as an additional source of information concerning temperature changes in longwall, which depends, besides presence of electrical equipment also on goafs thermal activity. Of course one ought to calibrate sensors due to additional heat sources (cutter, conveyor etc.), but measured constant rise of temperature in this place could be the signal for early prevent action. Unfortunately this kind of solution meets the same constrains as previous one. Therefore the best solution for approaching this phenomenon is to deal with it numerically. Presented paper discuss results of three – dimensional CFD simulation of temperature and carbon monoxide propagation inside goafs – longwall complex. Because of high Reynolds number, Re > 105, which implies turbulent fl ow in longwall excavations, the calculation was realized using k-ω-SST model (proved to be suitable by Wala).

 

The simulation results are represent in a form of three-dimensional distributions of temperature inside goafs and longwall zone (fi g. 9), carbon monoxide concentration (fig. 14) and as a two dimensional charts of temperature and carbon monoxide in selected places of goaf-longwall complex (fig. 11 and 16). Presented case should be treat as an introduction to further analysis of fire in a goafs phenomenon. Further analysis should contain more sophisticated models of fire source and combustion products propagation.