冷冻取芯过程煤芯瓦斯解吸特性试验研究

Experimental study on gas desorption characteristics of coal core in frozen coring process

为探究冷冻取芯过程煤芯瓦斯解吸特性,基于模拟试验的相似性,依托自主研发的含瓦斯煤冷冻取芯响应特性测试平台,开展不同变质程度煤样(长焰煤、贫瘦煤、无烟煤)及不同吸附平衡压力(1.0,2.0,3.0,4.0 MPa)下冷冻取芯过程煤芯瓦斯解吸特性试验研究。研究结果表明:冷冻取芯过程中,煤芯瓦斯解吸量与吸附平衡压力及煤变质程度呈正相关关系;在煤芯瓦斯解吸过程中存在倒吸现象,煤与瓦斯初始吸附平衡压力越大,煤的变质程度越高,倒吸开始时间越迟;冷冻取芯过程中,瓦斯解吸速度与吸附平衡压力及煤变质程度呈正相关关系,且瓦斯解吸速度随吸附平衡压力及煤变质程度变化曲线符合幂函数关系。

In order to study the gas desorption characteristics of coal core in the process of frozen coring,based on the similarity of simulation test,and relying on the self-developed test platform for the response characteristics of frozen coring on gas bearing coal,the experimental research on the gas desorption characteristics of coal core in the process of frozen coring was carried out under different metamorphic degrees of coal(long flame coal,lean coal,anthracite)and different adsorption equilibrium pressures(1.0,2.0,3.0,4.0 MPa).The results showed that there was a positive correlation between the desorption amount of coal core gas and the adsorption equilibrium pressure and the metamorphic degree of coal.The phenomenon of back suction existed in the desorption process of coal core gas,the larger the initial adsorption equilibrium pressure of coal and gas,the higher the metamorphic degree of coal,and the later the start time of back suction.In the process of frozen coring,there was a positive correlation between the gas desorption velocity and the adsorption equilibrium pressure and the metamorphic degree of coal,and the change curve of gas desorption velocity with the adsorption equilibrium pressure and the metamorphic degree of coal conformed to power function.