综放采空区容易发生自燃。以往对采空区“三带”的划分主要通过向采空区埋管观测来实现,对于现场观测不能实现的情况下,采空区自燃危险区域难以判定。笔者通过对采空区渗流场的数值模拟,得到采空区渗流速度及O2浓度的分布。结合实验测得的煤自然发火期和自燃临界参数,对采空区“三带”进行划分。该方法计算量比模拟采空区煤自燃全过程少得多,但划分精度却能够满足实际防灭火需要。
Spontaneous combustion is easily to take place in mined out area of fully mechanized top coal caving workface. Partition of self - heating zone in the area is mainly based on observed result from mined out area with pre-embedded sensors. In some cases, some parameters are hard to be observed which makes it difficult to plot out spontaneous combustion danger ous zone. Through numeric simulation, distribution of oxygen concentration and velocity of air flow in mined out area are determined. With the simulating result together with critical value and duration of coal spontaneous combustion obtained from experiment, boundary of self-heating zone is partitioned. The result set solid foundation for preventing spontaneous combustion. Compared with numeric modeling of the whole process of coal spontaneous combustion, much smaller amount of calculation is required, yet precision can satisfy the demand to predict and prevent spontaneous combustion in gob.