Partition of Spontaneous Combustion Three-zone in Goaf of Fully-mechanized Caving Face in Easy Self-ignition and Thick Seam

We proposed combined oxygen concentration method and temperature method to divide spontaneous combustion three-zone in goaf under the condition of continuous nitrogen injection, used Fluent software to simulate spontaneous combustion three-zone without nitrogen injection. On this basis, we concluded that the minimum safety advancing speed that restrained goaf spontaneous combustion. The results showed that the clear distribution of goaf spontaneous combustion three-zone can reduce the blindness of fire prevention and control work. Goaf spontaneous combustion three-zone scope based on numerical simulation can evaluate nitrogen injection effect in a certain extent. To speed up spontaneous combustion with forward speed and reduce its width is an important mean of preventing coal spontaneous combustion.