含水煤堆自燃高温位置特征的数值模拟与实验

Experiment and Numerical Simulation of High Temperature Region Distribution for Coal Pile Containing Water

为了研究含水煤堆自燃高温位置分布的特性,建立了含水煤堆内部非饱和传热数学模型,利用数值模拟方法比较了含水煤堆和干煤堆自燃过程中高温区分布位置,并进一步计算了高、中、低水分下3种煤堆自燃高温位置的分布趋势,结果表明:干煤堆由表面往内依次形成散热带、自然带,高温位置深入煤堆表面数米的中下部。含水煤堆深部蒸发缓慢,不易自燃,高温位置逆迎风面向干燥区域发展,水分越高,高温区越接近表面。依据模拟结果进行了验证实验,二者结论相符,煤场安全管理应考虑煤堆的水分含量,预估自然起火位置。

In order to study the distribution characteristic of location of high temperature region during coal pile spontaneous combustion, the unsaturated heat transfer mathematical model of coal pile containing water was established. Then the numerical simulation was used to compare the high temperature region position between coal pile containing water and dry coal pile, and the location of high temperature region distribution of three kinds coal pile for high water level, middle level and low level is calculated.The results show that the heat dissipation area, spontaneous combustion area and high temperature inside the lower-middle part of coal pile are formed from the surface to the interior. Due to slow evaporation, the deep part is not combustion easily and the high temperature region can develop forward to dry part reverse the windward side; the higher the water, the closer the high temperature zone is to the surface. According to this conclusion, the experiment was carried to verify it, and the results between them meet well, hence, the safety management of coal fields should consider the moisture content of coal piles to predict the location of spontaneous combustion.