Abstract Once the residual coal occurs spontaneous combustion in mine, it will cause a fire accident resulting in heavy personal injury and property damage. So it is of great significance for mine safety to quickly determine the location of dangerous areas of residual coal spontaneous combustion. A fracture-pore evolution model of goaf is constructing, the pore evolution and porosity distribution in a goaf overburden are simulated by the distinct-element modeling software Particle Flow Code (PFC). By compiling the extracted porosity distribution data into Fluent using a User Defined Function (UDF), a dynamic porosity model of goaf is being proposed. With this model, the air flow field in a goaf is simulated, and the regular air distribution pattern in that area is obtained. Using oxygen concentration as the indicator, the residual coal spontaneous combustion-prone region in the goaf is identified, and the results are basically the same as those determined from real mine measurements. The consistency in results validates that the residual coal spontaneous combustion-prone region can be accurately and reliably identified by investigating the goaf flow field distribution under consideration of porosity dynamics. Our approach offers a new concept and method with a higher precision of results for identifying residual coal spontaneous combustion prone-regions in goafs, and it provides the basis for preventing and extinguishing goaf fires and guarantees the mine safety.

中文翻译：

---

动态孔隙度下基于采空区流场的煤自燃易发区识别方法

摘要 一旦矿井中余煤发生自燃，就会引发火灾事故，造成重大的人身伤害和财产损失。因此，快速确定残煤自燃危险区域的位置对矿山安全具有重要意义。正在构建采空区裂缝-孔隙演化模型，利用离散元建模软件粒子流代码（PFC）模拟采空区覆盖层孔隙演化和孔隙度分布。通过使用用户定义函数 (UDF) 将提取的孔隙度分布数据编译成 Fluent，提出了采空区的动态孔隙度模型。使用该模型模拟采空区的空气流场，获得该区域的规则空气分布模式。以氧气浓度为指标，对采空区残煤自燃易发区进行了识别，其结果与实测结果基本一致。结果的一致性证明，通过研究考虑孔隙度动力学的采空区流场分布，可以准确可靠地识别残煤自燃易发区域。该方法为采空区残煤自燃易发区的识别提供了一种新的概念和方法，结果精度更高，为预防和扑灭采空区火灾提供了依据，保障了矿山安全。结果的一致性证明，通过研究考虑孔隙度动力学的采空区流场分布，可以准确可靠地识别残煤自燃易发区域。该方法为采空区残煤自燃易发区的识别提供了一种新的概念和方法，结果精度更高，为预防和扑灭采空区火灾提供了依据，保障了矿山安全。结果的一致性证明，通过研究考虑孔隙度动力学的采空区流场分布，可以准确可靠地识别残煤自燃易发区域。该方法为采空区残煤自燃易发区的识别提供了一种新的概念和方法，结果精度更高，为预防和扑灭采空区火灾提供了依据，保障了矿山安全。