水分自然侵入促进含瓦斯煤解吸效应实验研究

Experimental study on desorption promoting effect of coal containing gas by water natural invasion

为定量研究水分自然侵入对含瓦斯煤解吸促进影响效果,利用自制的"高压吸附-水分自然侵入-数据自动采集"实验系统,对不同水分含量自然侵入含瓦斯煤后的瓦斯压力变化进行了连续监测。结果表明:水分侵入后依靠竞争吸附能置换出吸附瓦斯,从而促进含瓦斯煤瓦斯解吸,其促进效果与煤样含水率相关;当煤样含水率由2%增至12%时,瓦斯置换量由2.18ml/g增至4.48ml/g,瓦斯置换率由11.48%增至23.83%,煤样吸水饱和前,含水率Mad与瓦斯置换量Q和置换率η之间满足Q=1.695Mad/(1+0.3Mad)和η=8.85Mad/(1+0.29Mad)关系模型,煤样吸水饱和时,水分对瓦斯解吸的促进效果达到极限值;工程应用中可利用水分对瓦斯解吸的促进影响效应进一步提高瓦斯抽采率。

In order to quantitatively investigate the effect of water natural invasion on desorption promoting of coal containing gas,the change of gas pressure for coal containing gas by water natural invasion with different water content was continuously monitored by using the self- made ＂ high pressure adsorption- water natural invasion- automatic data acquisition＂ experiment system. The results showed that the adsorbed gas could be replaced by competitive adsorption after water invasion,which could promote the gas desorption of coal containing gas,and the promotion effect was related to the water content of coal sample. When the water content increased from 2% to 12%,the gas replacement amount increased from 2. 18 ml / g to4. 48 ml / g,and the gas replacement rate increased from 11. 48% to 23. 83%. Before water content reached the saturation,the water content Mad,gas replacement amount Q and gas replacement rate η met the relationship models Q = 1. 695 Mad /（ 1＋ 0. 3Mad） and η = 8. 85 Mad /（ 1 ＋ 0. 29Mad）. The promoting effect of water on gas desorption stretched to the limit when the water content reached the saturation. The promoting effect of water on gas desorption can be using in engineering practice to further improve the gas drainage rate.