Research on the division method of the dangerous area of coal spontaneous combustion in goaf based on multi-parameter

The distribution range of coal spontaneous combustion hazard area in goaf is affected by many factors, such as air leakage intensity, floating coal thickness and volume fraction of oxygen. Taking 202 working face of Wangjiashan Coal Mine as the research object, spontaneous combustion characteristic parameters such as heat release intensity and oxygen consumption rate of coal samples are measured by using the coal spontaneous combustion test device in unit of kilogrm, and calculate the threshold value (floating coal thickness, volume fraction of oxygen, air leakage intensity, shortest ignition period, oxygen consumption rate) of the dangerous area division parameters of goaf combined with the theoretical formula. Based on these key parameters, a division method of the coal spontaneous combustion dangerous area in goaf is constructed. Through beam tube analysis and Fluent fluid simulation technology, and by observing the distribution law of oxygen concentration field and air flow field in goaf, the "three regions" of coal spontaneous combustion in goaf of large inclination face and the daily minimum safety advance degree of working face in Wangjiashan Coal Mine are determined. The research results have certain guiding significance for on-site fire prevention and extinguishing work.