Abstract: To understand the change of temperature and heating area, in different time, in the process of spontaneous combustion of goaf under “U” type ventilation, the model was proposed based on the theory of particle flow. The three basic problems of Oxygen equivalent flow and reaction with the coal were solved, and implemented with FISH. According to the actual working condition, the heating process was simulated, which could be divided into three stages, and the characteristics of the six warming development time were analyzed, finding that the heating area change was related with the oxygen flow in the process of spontaneous combustion of coal. Collection of the six time of heritage coal actual temperature, and the difference between these and simulation results were analyzed; It was generated that the coal seam crack considering cutting coal should also be additional. The improved model results still exist certain differences with the actual heating area change, but in terms of the relationship between the heating time and temperature is more accurate, the spread of degree of heating area is much closer to the truth.

Key words: u type ventilation, goaf, spontaneous combustion, pfc, coal seam crack, simulation and improvement