密闭液封堵煤芯瓦斯机理分析及应用

Mechanism analysis and application of using sealing-fluid to envelop coal-core gas

阐述了取芯过程中的密闭液封堵煤芯瓦斯技术,构建了气体在液体里的运移力学平衡方程,得出了瓦斯气体运移速度的解析表达式,采用数学方法绘制出了它与时间的关系曲线,通过积分得出了不同参数条件下的瓦斯气体运移位移,最后,开展了密闭液封堵煤芯瓦斯的现场取芯试验。研究结果表明,随着运移时间的增长,瓦斯运移速度逐渐降低,这种变化趋势既不是线性的,也不呈指数规律,而是介于两者之间;瓦斯气体的运动位移与瓦斯初始流速和瓦斯气体直径成正比,与液面至气体顶部的距离和液体粘度成反比,阻力系数的影响不大;在取芯过程中,密闭液能够包裹煤芯,并有效防止瓦斯漏失。

The paper expounds the technology of using sealing-fluid to envelop coal-core gas while obtaining a coal-core.A mechanics balance equation about gas moving in the liquid is constructed,and an expression about gas moving speed is formulated.By using mathematics method,a relation curve of gas moving speed to the time is drawn,and the gas moving displacements are obtained under different conditions.Based on the above,a trail of fetching a coal core was conducted by using sealing-fluid to envelop the coal core.The result shows that,with the lasting of gas moving time,the gas moving speed slows down gradually.The developing trend between them is neither linear,nor on index law,but between the linear and index law.The moving displacement is in direct ratio to the gas initial moving speed and the gas diameter,and it is in inverse ratio to the distance between the liquid surface and the gas＇ upper face and is also in inverse ration to the liquid＇s viscosity,while the resistance coefficient has no big influence to it.In the process of fetching a coal core,the sealing fluid could seal the coal core to prevent gas leakage effectively.