风障联合压实防治煤堆自燃技术工艺参数优化

为提高煤堆自燃的防治效果，降低经济成本和提高施工的灵活性，基于煤堆自燃理论，使用COMSOLMultiphysics 5.0数值仿真软件，建立煤堆自燃模型，研究了煤堆最高温度和自然发火期变化及相关措施实施后最高温度降低规律，对比了单独压实、独立风障和风障联合压实的温度降低量，优化了联合措施的工艺。结果表明，煤堆孔隙率越小，自燃风速范围越宽，最小、最易、最大自燃风速越大；单独进行煤堆压实存在因孔隙率增加而降低的最低不宜风速；针对6 m高煤堆单独使用风障时，只有风障高12 m、距离煤堆25 m才能避免煤堆自燃；风障联合压实措施中，风障高7.5~9 m，设置距离煤堆10~30 m即能保证煤堆不自燃。说明联合的煤堆最高温度降低量更大，且能扩大压实的适用范围，降低风障高度，节约经济成本，增加风障现场施工的灵活性。

Parameter optimization on prevention and control technology for spontaneous combustion of coal stockpile by combined method of compaction and wind barrier

In order to improve the prevention and control effect of spontaneous combustion in coal stockpile, decrease the economic cost and increase the flexibility of construction, a model of spontaneous combustion in coal stockpile was established by using the numerical simulation software of COMSOLMultiphysics5.0 based on the theory of coal spontaneous combustion. The variation of maximum temperature and spontaneous combustion time of coal stockpile were studied, and the reduction law of maximum temperature after implementation of relevant measures was analyzed. The values of temperature reduction by single compaction, independent wind barrier and combination of compaction and wind barrier were compared, and the technology of combined measure was optimized. The results showed that, the smaller the porosity of coal stockpile, the wider the wind velocity range of spontaneous combustion, and the higher the smallest, most easily, largest wind velocity of spontaneous combustion. In case of single compaction of coal stockpile, there exists the minimum inappropriate wind velocity, which decreases with the increase of porosity. In case of independent wind barrier for coal stockpile with 6 m height, only when the height of wind barrier is 12 m and the distance from coal stock pile to wind barrier is 25 m, the spontaneous combustion of coal stockpile can be avoided. When adopting the combined measure of compaction and wind barrier, the spontaneous combustion of coal stockpile can be avoided when the height of wind barrier is 7.5-9 m and the distance from coal stock pile to wind barrier is 10-30 m. The results showed that the combined measure of compaction and wind barrier has a larger reduction in maximum temperature of coal stockpile, moreover it can enlarge the applicability of compaction, reduce the height of wind barrier, save the economic cost and increase the flexibility of field construction on wind barrier.