解吸实验初期高速涌出的游离瓦斯使得不同损失时间条件下观测到的解吸曲线形态发生剧烈变化，为实验室准确测定基质吸附态瓦斯表观扩散系数，以及工程中精确测定K1值与损失瓦斯含量带来了不便。基于瓦斯流动与扩散的竞争互抑关系，建立了引入游离瓦斯流动的全浓度表观扩散模型，确定了游离瓦斯和吸附瓦斯对于整体逸散瓦斯的贡献变化，同时构建了K1值时因衰减数学模型。利用自主研发的瓦斯解吸自动测试装置，精确测定了初期瓦斯解吸曲线，并获得了损失时间为1 min，5 min及10 min条件下的表观扩散系数有效值。研究结果显示：随解吸时间的延长整个解吸过程可分为三个阶段，分别为游离瓦斯流动主控阶段、过渡阶段和基质吸附瓦斯扩散主控阶段；裂隙游离瓦斯量与解吸时间呈线性规律，基质吸附瓦斯量与解吸时间符合单孔扩散模型规律，其在短时间内又符合t模型；随着损失时间增大，游离瓦斯在整体逸散瓦斯中的贡献逐渐减小，而吸附瓦斯扩散的比重逐渐增大，在宏观上表现为解吸曲线线性段缩短，而曲率增加；依此推导出的表观扩散系数和K1值亦随之逐渐减小，且减小速度初期较大。利用表观扩散系数时因衰减关系，论文最后给出了K1值及损失量测定的有效测算时间区间，并建立了精确度更高的瓦斯损失量推算模型，将原有t模型对实验样品数据的拟合度提升了20.8%。研究结果有助于煤与瓦斯突出防治工作中提升相关瓦斯指标测算的精准度。

Due to high speed free gas from initial desorption,the desorption curve shape may experience a sharp variation with different loss time,which brings some barriers to the laboratory measurement of gas apparent adsorption diffusion coefficient in matrix and the accurate measurement of K1 value and loss gas content in engineering practice. Based on the competition relationship between gas flow and diffusion,the whole concentration apparent diffusion model considering the free gas flow influence was established,and the contribution of gas flow and gas diffusion in initial desorption was obtained. Meanwhile,the attenuation model of K1 value as the loss time goes was established. A self developed gas desorption automatic test apparatus was used to the initial gas desorption curve,and the apparent gas diffusion coefficients with loss times of 1 min,5 min and 10 min were obtained. The results show that the whole desorption can be divided into three stages as the desorption goes,which are free gas flow dominant stage,transition stage and adsorbed gas diffusion dominant stage. The free gas volume in fractures and the desorption time obey a linear relationship,while the adsorbed gas in matrix and the desorption time obey the unipore diffusion model,and at a short time,they obey the   model. With the increase of loss time,the contribution of free gas in the whole desorption becomes smaller,while that of adsorbed gas becomes larger. The linear stage of the desorption curve shortens and the curvature of desorption curve increases at the macro level. The deduced apparent diffusion coefficient and K1 value become smaller and the decreasing speed is large in the initial stage. With the attenuation model of gas apparent diffusion coefficient,the effective measuring time zones of K1 value and loss content were obtained. Besides,a new model to deduce loss content with higher accuracy was given. Compared to the original model,the fitting degree of the experimental data is improved by 20.8%. 

1 试验

   1.1 试验样品

   1.2 解吸试验

2 结果与分析

   2.1 不同损失时间条件下的瓦斯解吸特性

   2.2 不同损失时间条件下的瓦斯表观扩散系数

3 讨论

   3.1 类瞬态扩散衰减模型的不同损失时间下表观扩散系数衰减模型

   3.2 游离瓦斯流动与吸附瓦斯扩散的竞争关系

   3.3 游离瓦斯流动与吸附瓦斯扩散在宏观解吸中的控制作用演化

   3.4 K1及损失量有效测算时间区间判定

   3.5 瓦斯损失量推算的高拟合度模型

4 结论