Study on Stereoscopic Distribution Law of Spontaneous Combustion “Three-zone” in Goaf of Fully Mechanized Working Face with Large Mining Height

In order to explore the distribution law of spontaneous combustion “three-zone” in goaf at different heights in fully mechanized working face with large mining height, taking 3102 fully mechanized working face of Mataihao Coal Mine as the research object, a stereoscopic sampling and analysis system of spontaneous combustion “three-zone” in goaf of the working face was constructed. By analyzing the gas change rule of indexes of coal spontaneous combustion, such as oxygen, carbon monoxide, carbon dioxide, etc., the spontaneous combustion hazardous areas at different heights of goaf were divided. The hazardous area of stereoscopic spontaneous combustion is determined by establishing a numerical model and using numerical simulation software. The results show that the “spontaneous combustion zone” of fully mechanized working face with large mining height gradually widens along the vertical height, and the spontaneous combustion hazardous area becomes larger. When taking fire prevention measures, such as nitrogen injection, grouting and three-phase foam injection, the height and scope of perfusion should be increased.