松散煤堆自燃高温区时空演化规律仿真研究  

Simulation research on spatio-temporal evolution of high temperature zone of spontaneous combustion of loose coal pile

作　　者：王建国 赵思蕊 王康 WANG Jianguo;ZHAO Sirui;WANG Kang(School of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]西安科技大学安全科学与工程学院,陕西西安710054

出　　处：《矿业安全与环保》2023年第3期37-41,47,共6页Mining Safety & Environmental Protection

基　　金：国家自然科学基金项目(51974232);陕西省自然科学基金项目(2017JM5066)。

摘　　要：为研究松散煤堆在储运中高温区的自燃过程及影响因素,利用COMSOL建立了三维典型松散煤堆物理模型,通过理论分析确定了煤堆在速度场、氧浓度场和温度场等多场耦合作用下的模型参数,采用多物理场耦合控制方程进行模拟解算。结果表明:三维典型松散煤堆的自然发火期为57 d,高温区呈“水滴”状对称分布在煤堆迎风侧中下部;风速在0.001~0.35 m/s内时,自然发火期随风速的增大先缩短后延长,当风速超过3.5 m/s时,煤堆内部温度不再随时间变化,且远低于自燃临界温度;随煤堆孔隙率的增大,煤堆自燃所需时间大幅缩短;煤堆自然发火期与煤堆堆积高度呈正相关关系,改变堆积角度对煤堆自燃的影响较小。In order to study the process of spontaneous combustion and the influencing factors of loose coal pile in high temperature zone during storage and transportation,a three-dimensional typical physical model of loose coal pile was established by COMSOL.Through theoretical analysis,the model parameters of coal pile under multi-field coupling of velocity field,oxygen concentration field and temperature field were determined,and the equation of multi-physical field coupling control was used for simulation solution.The results show that the spontaneous combustion period of three-dimensional typical loose coal pile is 57 d,and the high temperature zone is distributed symmetrically in the middle and lower part of windward side of coal pile;when the wind speed is in the range of 0.001 m/s to 0.35 m/s,the spontaneous combustion period first shortens and then prolongs with the increase of wind speed.When the wind speed exceeds 3.5 m/s,the internal temperature of coal pile no longer changes with time and is far below the critical temperature of spontaneous combustion;with the increase of the porosity of coal pile,the time of spontaneous combustion of coal pile is greatly shortened;the spontaneous combustion period of coal pile is positively correlated with the stacking height of coal pile,and changing the stacking angle has little effect on the spontaneous combustion of coal pile.

关 键 词：煤堆自燃 自然发火期 多场耦合 高温区 时空演化 

分 类 号：TD752[矿业工程—矿井通风与安全]