Comparative experiment study on fire prevention and extinguishing in goaf by N2-water mist and CO2-water mist

Abstract

In order to compare and analyze the fire prevention and extinguishing effect of N2-water mist and CO2-water mist in goaf, the TG-DTG-DSC thermal analysis experiment of inhibiting coal combustion and the experiment of extinguishing burning residual coal in goaf by N2/CO2-water mist were carried out. In the thermal analysis experiment of 20~850 °C, N2/CO2-water mist increased the pyrolysis temperature T2 and the ignition temperature T3, decreased the combustion mass loss of the whole process, decreased the amount of endothermic at the early stage and exothermic at the later stage of the reaction, and the effect of CO2-water mist was more obvious. For the burning residual coal in a large scale of goaf, N2/CO2-water mist decreased the temperature, the amount of CO, CO2, H2, and the consumption of O2, and the effect of CO2-water mist was better than that of N2-water mist. Although N2/CO2-water mist could inhibit CH4 emission, there was no significant difference between them. There was no re-ignition after stopping the application of N2/CO2-water mist.