Study on Combustion Characteristics and Evacuation during Intake Airway Fire in Coal Face under Different Ventilation Conditions

摘要

The exogenous fire is one of the major disasters of mines. It is difficult to put them out but easy to result in serious casualties and property losses. Until now, the fire combustion in mines and smoke flow characteristics under multi-factor coupling effect of wind speed, wind direction, fire source and so on are still not clear. Moreover, the interaction mechanism between fire and people escape has still not been revealed. In order to solve the above problems, this paper used the FDS numerical simulation method to study the parameter values of working face temperature and visibility of laneway as the fire occurs as well as their changes, so as to obtain the influences of fire source position and fire power on the smoke spread rate of fire in the laneway. Then, the function expressions of smoke spread rate related to the fire source position and fire power were derived, respectively, and the rationality of theoretical prediction model of longitudinal attenuation of smoke temperature was verified. Furthermore, the fire characteristic parameters and their change rules under the inverted ventilation were studied, and the optimal scheme of wind control was obtained. The results showed that the increase of inverted ventilation speed could accelerate the discharge of smoke flow from the laneway. Moreover, when the inverted ventilation speed was between 2.2 m/s and 2.7 m/s, there was an optimal wind rate for smoke discharge, which could provide relatively safe conditions for evacuation. In addition, when the power of the fire source was 10 MW, the critical wind speed to prevent the smoke flow reversal was 1.6 m/s under the condition of local inverted ventilation. Finally, this study simulated the personnel escape behavior in combination with Pathfinder to build the prediction models of evacuation time and evacuation speed in the laneway and working face. Simultaneously, the necessary time for personnel escape was analyzed, which provided a basis for the safe evacuation of personnel in the case of fire.