干湿循环对含瓦斯煤渗透率的影响

摘要

In order to study the effect of dry-wet circulation on permeability of coal containing gas, by using the self-developed coal containing gas thermal-hydrological-mechanical ( THM) coupling experimental equipment, an experimental study about the permeability of raw coal was made under different dry-wet cycles and different average effective stresses. The research results showed that: under the condition of a constant temperature and dry-wet cycles, with the increase of average effective stress, the permeability of coal samples showed a logarithmic function decreas. The sensitivity coefficient of average effective stress to permeability increased with the increase of coal sample dry-wet cycles, decreased with the increase of average effective stress. Under the condition of a constant temperature and an average effective stress, the permeability of coal samples increased with the increase of coal sample dry-wet cycles, and the relationship between coal sample permeability and dry-wet cycle can be expressed by linear function. The more dry-wet cycles, the stronger the water absorption of the coal sample, the greater the saturation moisture content.%为了研究干湿循环对含瓦斯煤渗透率的影响,采用自行研制的含瓦斯煤热流固耦合三轴伺服渗流实验装置,对原煤试样进行了不同平均有效应力、不同干湿循环次数条件下的渗流实验.研究结果表明:在恒定温度和干湿循环次数下,煤样的渗透率随平均有效应力的增加呈对数函数关系减小;平均有效应力对渗透率的敏感性系数随煤样干湿循环次数的增加而增加,随平均有效应力的增加而减小;在恒定温度和平均有效应力下,随煤样干湿循环次数的增加,煤样渗透率增加,且煤样渗透率和干湿循环次数关系可以用线性函数表示;干湿循环次数越多,煤样的吸水性越强,饱和含水率越大.