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工作面突出危险性预测是防治煤与瓦斯突出的一个重要环节,提高预测指标测定的准确性对于减少“低指标突出”现象,保证安全生产有重要意义。钻屑解吸指标K1是工作面煤与瓦斯突出预测的重要指标之一。基于扩散理论和钻屑瓦斯解吸指标K1物理意义建立了K1的数学表达式,根据该式研究了瓦斯压力、损失时间、煤粒粒度、扩散系数对K1的影响。结果表明:钻屑解吸指标K1与瓦斯压力呈幂指数关系;相同条件下,损失时间越长测得的K1越小,并且钻屑的粒度越小表现越明显;扩散系数表征瓦斯绕过微孔和煤基质的能力,相同条件下扩散系数越大测得的K1越大;煤粒粒度对K1的影响较大,现场测定过程中煤粒粒度组成对获得真实的K1和准确的临界值至关重要。
Outburst danger prediction of working face is an important step to prevent coal and gas outburst. Improving the accuracy of forecasting index measurement is of great significance for reducing the phenomenon of “low index highlighting” and ensuring safe production. Drilling cuttings desorption index K1 is one of the important indexes of coal and gas outburst prediction in working face. Based on the theory of diffusion and the physical meaning of gas desorption index K1, a mathematical expression of K1 was established. According to the formula, the influence of gas pressure, loss time, coal particle size and diffusion coefficient on K1 was studied. The results show that the desorption index K1 of drill cuttings shows a power-exponent relationship with the gas pressure. Under the same conditions, the smaller the K1 measured when the loss time is longer, and the smaller the drill cuttings’ particle size is, the more obvious the diffusion coefficient characterizes gas bypassing micropores And coal matrix. Under the same conditions, the larger the diffusion coefficient is, the larger the K1 is. The greater the effect of coal particle size on K1, the smaller the particle size of coal particles is, important.