基于阻抗法煤体中瓦斯水合动力学研究

为探寻水合物技术在瓦斯突出防治方向上的应用工艺,利用瓦斯水合固化过程阻抗特性监测实验装置,研究4组不同煤体孔隙裂隙分布对瓦斯水合过程的影响,获取了煤体中瓦斯水合过程阻抗曲线,计算了瓦斯水合物生长速率与含气量。结果表明:实验釜上层位阻值增大,中层位与下层位阻值减小,瓦斯水合物集中在实验釜上层位与中层位形成;相同热力学条件下4组体系中瓦斯水合物生长速率分别为0.180,0.083,1.747,0.448 cm~3/min,水合物含气率分别为1.9×10~(-3),6.3×10~(-3),2.1×10~(-3),1.6×10~(-3)mol/cm~3,说明孔隙裂隙较发育煤体中瓦斯水合速率较快,所形成水合物具有较高的含气量。不同孔隙裂隙煤体中单位体积瓦斯水合物含气量不同,孔隙裂隙较发育煤体中瓦斯水合物形成量较大,基于准均匀占据理论,孔隙裂隙较发育煤体中瓦斯水合物所含空晶笼较多。

Mine gas hydration kinetics in coal based on impedance method

To explore the application of hydrate technology in preventing coal and gas outburst,the impedance monitoring experiment devices of mine gas curing process is used to study the effect of four kinds of different pore and fractal distributions on mine gas hydration process.Meanwhile,the impedance characteristic curve of mine gas hydration process in coal is obtained.The growth rate and gas content of mine gas hydrate are calculated.The results show that impedance value increases in the upper layer and it decreases in the middle and lower layers of the experimental reactor.Mine gas hydrate mainly forms in the upper and middle layers of the experimental reactor.Under the same thermodynamic conditions,the gas hydrate formation rate in the four experimental systems is 0.180,0.083,1.747 and 0.448 cm3/min respectively.The gas fraction is 1.9×10-3,6.3×10-3,2.1×10-3 and 1.6×10-3 mol/cm3 respectively.The above data indicates that the mine gas hydration rate is quicker in the coal which contains more pore and fractures due to the high gas content in mine gas hydrate.The gas content of unit volume mine gas hydrate is different with the varying pore and fractures in coal and the quantity of mine gas hydrate is larger in the coal with more pore and fractures.Based on the theory of homogeneous occupy,the mine gas hydrate contains more hollow cages in the coal with more pore and fractures.