大功率声波作用下煤层气吸附特性及其模型

Adsorption model and law of methane under the effect of high-power acoustic wave

利用声波的机械振动效应、热效应和空化效应,自行设计了大功率声波作用下甲烷吸附/解吸实验装置,实验研究了不同声强、不同频率的声波作用下不同煤样对甲烷的吸附特性。实验结果表明,不加声波与加声波条件下煤吸附甲烷的规律相同,而声波作用下煤对甲烷吸附的能力降低,且煤吸附甲烷量随声强的增大而降低;应用Langmuir方程、D-R方程、Freundlich方程、BET方程对实验数据进行拟合,得出:Langmuir模型和D-R模型能较好地反映煤吸附甲烷规律,且吸附模型参数a,K',Qm,Qn减小,且与声强J呈线性递减关系。在现有吸附模型的基础上,引入声强J参数,通过修正,建立了声波作用下煤对甲烷的吸附模型,并确定了模型参数的数值分析求解方法。

The apparatus of CH4 adsorption/desorption with high-power acoustic wave influence was designed based on the acoustic wave＇ s mechanical vibration effect, thermal effect and the cavitation effect. The adsorption tests of meth- ane on coal under different acoustic frequencies and intensities were carried out to reveal the adsorption characteristics of methane on coal. And the results show that the adsorption regularity of methane on coal under the effect of acoustic wave is in accordance with that without acoustic effect, and under the effect of acoustic wave, adsorption ability of methane on coal reduces while amount of adsorption goes down with the increasing acoustic intensity. The experiment data were fitted based on the Langmuir Equation, Freundlich Equation, BET Equation and D-R Equation, and it was found that Langmuir equation and D-R equation are more precise, and the parameters a,K＇, Qm, Qn decrease under the effect acoustic wave, which have linear relationship with the sound intensity J. Then the correction term were intro- duced into the existing models forming new models of coal adsorbing methane under the effect of acoustic wave, and the numerical solution of the parameters was presented.