不同温度和压力条件下煤样对瓦斯的吸附特性研究

Study on Gas Adsorption Characteristics of Coal Sample Under Different Temperatures and Pressures

基于注热增产煤层瓦斯的研究背景,为了探索不同温压环境下柱状煤芯甲烷吸附特征,在实验室开展了温度为20℃,40℃,60℃,初始吸附压力为2.0MPa和4.0MPa的柱状煤芯甲烷吸附实验,对比分析了温度对吸附量、吸附速度、吸附饱和度、进扩散系数的影响。结果表明:甲烷吸附量随温度的增高呈递减趋势,温度升高煤基质对甲烷的吸附能力减弱;初始阶段甲烷吸附速度较高,前12h甲烷吸附速度呈急剧减小趋势,平均衰减幅度达到93.4%,后期吸附速度缓慢;吸附饱和度随温度的增高而减低,柱状煤芯甲烷吸附过程后期呈现出吸附速度慢,耗费时间长的特征。采用柱状煤芯瓦斯扩散模型计算了进扩散系数D值,D值随着实验环境温度的增大而减小。

Under the research background of increasing heat to improve the gas production in coal seam,to explore the methane adsorption characteristics of columnar coal core under different temperatures and pressures,the methane adsorption experiments were carried out in the laboratory under the temperatures of 20℃,40℃and 60℃,as well as the initial adsorption pressures of 2MPa and 4MPa.The effects of temperature on the adsorption amount,adsorption rate,adsorption saturation and intake diffusion coefficient were compared and analyzed.The results showed that with the increase of temperature,the methane adsorption amount decreased,and the methane adsorption capacity of high-coal matrix was weakened.Methane adsorption at the initial stage was fast,the rate of methane adsorption at the first 12hdecreased sharply,the average reduction range reached 93.4%,and the adsorption speed was slow in the later period.The adsorption saturation decreased with the increase of temperature,the methane adsorption process of columnar coal core was characterized by slow adsorption speed and long time consumption.The intake diffusion coefficient D was calculated by the gas diffusion model of the columnar coal core,and the D value decreased with the increase of temperature.