渗透剂溶液侵入对瓦斯解吸速度影响实验研究

Experimental study of penetrant solution effects on gas desorption

针对瓦斯抽采后回采工作面瓦斯超限问题,利用自主研发的外液侵入条件下瓦斯解吸实验装置,首次实验研究了有、无渗透剂溶液侵入条件下含瓦斯煤体的瓦斯解吸速度变化规律,探讨了利用水锁防止工作面瓦斯超限的可行性与实施途径.结果表明:渗透剂溶液侵入后对瓦斯解吸具有水锁损害作用,在其作用下能够降低和延缓含瓦斯煤的瓦斯解吸速度;水锁对瓦斯解吸的阻碍作用随瓦斯压力水平的降低而增加,尤其在瓦斯压力水平为1.0MPa及以下时表现最为明显;在前1h之内,瓦斯解吸速度降低7%～26%;在12h时除压力水平为1.0MPa的含瓦斯煤体其瓦斯解吸速度降低26%外,其余各压力水平的瓦斯解吸速度均能够降低40%以上,表明随着时间的延长其效果也越明显;在前20min以内存在液置气现象.

An experimental measurement was developed to examine gas desorption from coal. Gas desorption was measured in the presence and in the absence of a penetrant. The feasibility of using a water barrier to prevent gas concentrations over the threshold limit from developing is discussed. The results show that the penetrant reduces the gas desorption rate from the coal. The blocking effect depends on gas pressure. The effect is most obvious for gas pressures be- low 1 MPa. In this situation the rate is reduced from 7~/~ to 26% during the first hour of the test. Twelve hours after beginning the test the amount of gas desorbed is reduced more than 40% from the control measurement. This shows that water penetrant can effectively extend the time required for gas desorption. The initial 20 minute period of the test shows a ＂liquid repla- cing gas＂ phenomenon. This study is relevant to the prevention of high gas concentrations at the coal working face.