Application of Liquid Carbon Dioxide Injection in Ground Drilling for Fire Preventing and Extinguishing in Goaf

In order to study the actual extinguishing effect of liquid carbon dioxide on goaf oxidation zone of 010905 working face with overlying goaf, by designing surface boreholes in a suitable location in the goaf at the back of the face, liquid carbon dioxide is injected into the selected “oxidation zone” area of the 010905 working face, so that the temperature, oxygen concentration and harmful gases in the goaf in the “oxidation zone” area can be effectively controlled after a large amount of liquid carbon dioxide is gasified, which ensures the safety of working face mining. After the liquid carbon dioxide was injected into the surface borehole and observed by using the preset beam tube and sensor in the closed joint, the experimental results showed that the temperature and oxygen concentration in the experimental area showed a straight downward trend, and the concentration of carbon dioxide gas showed a sharp rise first and then continued to decrease. The regional treatment effect was very obvious.