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为明确煤堆压实的适用性,使用COMSOLMultiphysics5.0数值仿真软件,建立变风速条件下不同孔隙率煤堆自热-自燃的二维数值模型,研究孔隙率(0.2~0.6)变化时煤堆在不同风速下(0.1~11.5 m/s)的最高温度,确定了不同孔隙率煤堆的自燃风速范围,比较煤堆压实前后最高温度与自然发火期变化,分析了煤堆压实的适用性.研究结果表明:随风速增加煤堆最高温度呈双指数变化;孔隙率越小自燃风速范围越宽,最小、最易、最大自燃风速与孔隙率之间具有负指数关系;压实可以对原孔隙率0.6的煤堆起到有效的保护作用,孔隙率0.5、0.4、0.3的煤堆分别在风速大于0.9 m/s、1 m/s、1.4 m/s时压实后,最高温度不降反升,自然发火期明显缩短;说明煤堆压实因煤堆孔隙率和环境风速不同存在不适用范围.
In order to clarify the applicability of coal compaction, COMSOLMultiphysics5.0 numerical simulation software was used to establish a two-dimensional numerical model of self-heating and spontaneous combustion of coal piles with different porosities under variable wind speed conditions. The changes of porosity (0.2-0.6) The range of spontaneous combustion wind speed of coal piles with different porosity was determined at the maximum temperature of 0.1 ~ 11.5 m / s. The changes of the maximum temperature before and after compaction and the spontaneous combustion period were compared. The results show that the maximum exponential temperature of coal is double exponential with the increase of wind speed, the smaller the porosity is, the wider the range of spontaneous combustion wind speed is, the smaller is the easiest and the easiest is the exponential relationship between maximum spontaneous combustion wind speed and porosity. Compaction can The original porosity of 0.6 coal piles played an effective protective effect, the porosity of 0.5, 0.4, 0.3 coal heap wind speed greater than 0.9 m / s, 1 m / s, 1.4 m / s when compacted, the maximum temperature Not lowering the ascent, the natural fire period was significantly reduced; that pile compaction due to coal pile porosity and environmental wind speed is not applicable range.