Numerical simulation of the temperature rise process caused by spontaneous combustion of coal body around roadways along comprehensive mechanized caving mining goaf

Finite element based numerical simulation method is adopted to study the air leakage state, oxygen consumption and temperature rise caused by spontaneous combustion in coal body around working roadways along one side of comprehensive mechanized caving mining goaf, and the seepage equation of air leakage, seepage flow-diffusion-consumption equation and heat transfer equation are combined and solved. The spontaneous combustion characters and temperature rise process in pillars of adjacent goafs are discussed emphatically, and we can conclude that there is a inversely-proportional relationship between spontaneous combustion period and oxygen consumption speed of coal while air leakage intensity has little influence on spontaneous combustion period. The range of high temperature zone in coal body will expand with the increment of intensity of air leakage, and the probability will also be higher relatively.