抑制煤堆自燃的新方法的理论与实验研究

Theoretical and Experimental Evaluation on a New Technique for Preventing Spontaneous Ignition of Stockpiled Coal

配制了一种以煤粉为主的可燃混合物,用于封闭煤堆表面以达到通过隔绝空气来抑制自燃的目的。建立了煤堆自燃过程的一维数学模型和煤自燃过程的实验装置,研究了边界上的空气扩散对于煤自燃过程的影响。数值模拟结果表明,在煤堆边界封闭的情况下,孔隙中的氧气消耗很快,与边界开放的情况相比,煤的温升速率较低,自燃的趋势显著减缓。实验结果表明,在边界封闭的情况下,煤样的温升速率明显低于边界开放时的温升速率,这既证实了煤堆中的空气扩散对煤自燃过程的制约作用,同时也表明了所配制的材料对空气的良好隔离作用。

A kind of coal-based combustible mixture was formulated to cover the surface of stockpiled coal for isolating the coal from air to prevent spontaneous ignition. Numerical and experimental studies were conducted on the influence of the diffusion of oxygen at the boundary of the coal stockpiles on spontaneous ignition, with a one-dimensional mathematical model and an experimental model of stockpiled coal. The results of numerical simulation show that when the coal stockpile is isolated from air,the concentration of oxygen decreases faster and the temperature increases slower compared to that in the coal stockpile without cover. Similarly, experimental results show that the temperature in the coal stockpile with cover increases slower than that in the coal stockpile without cover. These results not only demonstrate that the spontaneous ignition of coal stockpile is controlled by air diffusion,but also indicate that air can be effectively isolated with the mixture formulated by the authors.