摘要
为了揭示高压注入条件下N_(2)对不同含水率煤中CH_(4)置换效应影响,基于含水率为0.75%、1.5%和3%的3种煤样,开展了高压注N_(2)置换CH_(4)实验。实验结果表明:随着煤含水率的增加,煤吸附CH_(4)和N_(2)的能力表现出逐渐减弱的趋势,N_(2)的吸附量始终小于CH_(4)的吸附量,且N_(2)置换CH_(4)的能力逐步下降;在本实验压力条件下,CH_(4)预吸附平衡压力超出0.75 MPa越大,其N_(2)利用率越低。同时随煤含水量的增加,CH_(4)置换率、N_(2)注置比均出现逐步减小的趋势,因此可得CH_(4)置换率、N_(2)注置比均与煤的含水量呈负相关关系。实验含水煤样更好的还原井下处于潮湿环境中的原煤,通过CH_(4)置换率和N_(2)注置比的反馈得出,过大的注气压力并不能得到良好的注气效果,反而会降低该置换源气体的利用率,因此对井下注N_(2)置换煤层CH_(4)的工程技术来说,为避免盲目提高注气压力而造成N_(2)的置换效率下降的现象,建议井下煤层注N_(2)置换CH_(4)时,CH_(4)吸附平衡压力控制在0.75 MPa最佳。
In order to reveal the effect of N_(2)on CH_(4)displacement in coal with different water contents under high-pressure injection conditions,high-pressure injection N_(2)displacement experiments were conducted on three coal samples with water contents of 0.75%,1.5%,and 3%.The experimental results show that with the increase of coal moisture content,the ability of coal to adsorb CH_(4)and N_(2)shows a gradual weakening trend.The adsorption amount of N_(2)is always smaller than that of CH_(4),and the ability of N_(2)to replace CH_(4)gradually decreases;Under the pressure conditions of this experiment,the larger the pre adsorption equilibrium pressure of CH_(4)exceeds 0.75MPa,the lower its N_(2)utilization rate.At the same time,with the increase of coal moisture content,the CH_(4)replacement rate and N_(2)injection ratio show a gradually decreasing trend.Therefore,it can be concluded that the CH_(4)replacement rate and N_(2)injection ratio are negatively correlated with the coal moisture content.The experimental water containing coal sample can better restore the raw coal in a humid environment underground.Through feedback on the CH_(4)replacement rate and N_(2)injection ratio,it is found that excessive injection pressure cannot achieve good gas injection effect,but instead reduces the utilization rate of the replacement source gas.Therefore,for the engineering technology of replacing coal seam CH_(4)with N_(2)injection underground,in order to avoid the phenomenon of blindly increasing the injection pressure and causing a decrease in N_(2)replacement efficiency,It is recommended to control the equilibrium pressure of CH_(4)adsorption at 0.75 MPa when injecting N_(2)into underground coal seams to replace CH_(4).
作者
陈立伟
严越涵
赵明振
杨宏民
刘媛
CHEN Liwei;YAN Yuehan;ZHAO Mingzhen;YANG Hongmin;LIU Yuan(Collaborative Innovation Center of Coal Safety Production and Clean and Efficient Utilization,Jiaozuo,Henan 454000,China;School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454000,China;Engineering Research Center of Coal Mine Disaster Prevention and Rescue,Ministry of Education,Jiaozuo,Henan 454000,China)
出处
《煤矿现代化》
2024年第1期43-47,51,共6页
Coal Mine Modernization
基金
国家自然科学基金面上项目(52074104)
河南理工大学博士基金项目(B2020-2)。
