摘要
目的研究瓦斯气体在煤层中的流动特性对于揭示煤层瓦斯赋存机理和扩散运移特性具有重要意义。煤中微纳米级孔隙结构十分复杂,为研究煤层瓦斯气体在微纳米孔隙中的流动特性,方法以均质纳米多孔炭薄膜为测试对象,采用扫描电镜实验对其孔隙大小和孔隙率进行定性定量分析;利用纳米尺度气体流动特征实验装置开展微纳米孔隙的气体流动实验研究,通过对比分析传统达西渗流模型和适用于微尺度下气体流动模型,结果得到更为详细的微纳米孔隙内气体流动特性:纳米多孔炭薄膜的视渗透率随着进气口压力的升高而下降,二者呈负相关的线性变化规律;视渗透率随着努森数降低而降低,二者呈正相关的线性变化规律,表明气体在微纳米尺度下的流动不符合传统的达西定律,滑脱效应和气体扩散不可忽视。采用格子Boltzmann方法(lattice boltzmann method,LBM)模拟不同进气口压力下的气体流动,得到不同气体压力下出口的气体流量,与实验结果进行对比,LBM模拟的平均误差为8.25%,整体吻合性较好,表明LBM数值模拟可有效揭示气体在微纳米尺度下的流动特性。结论研究结果可为今后分析煤层中的瓦斯流动机制和流动规律提供理论借鉴。
Objectives It is important to study the flow characteristics of gas in coal seams to reveal the mechanism of coal seam gas storage and transport characteristics.The number and structure of micro and na⁃noscale pores in coal are very complex,and to study the flow characteristics of coal seam gas in micro and nanoscale pores,Methods homogeneous nanoporous carbon films were tested and their pore size and poros⁃ity were qualitatively,and quantitatively analyzed by scanning electron microscopy experiments;the experi⁃mental study of gas flow in micro and nano pores was carried out by using a nano-scale gas flow character⁃ization experimental device.Results A more accurate characterization of the flow of gases within micro-and nano-pores is obtained by comparing the conventional Darcy percolation model with a model applicable to gas flow at the micro-scale.The apparent permeability of nanoporous carbon films decreases with increasing inlet pressure in a negatively correlated linear law,while the gas permeability decreases with decreasing Knudsen number in a positively correlated linear law,indicating that the flow of gas at the micro-and nanoscale does not conform to the conventional Darcy’s law,and the slip effect and gas diffusion cannot be ne⁃glected.The lattice Boltzmann method is used to simulate the gas flow at different inlet pressures to obtain the outlet gas flow rate at different gas pressures.When compared with the experimental results,the average error of LBM simulation results is 8.25%,which is in good agreement with the test results,indicating that LBM numerical simulations effectively reveal the flow characteristics of gases at the micro-and nano-scale.Conclusions The results of the study can provide a reference for future research on gas flow mechanisms and flow patterns in coal seams.
作者
王登科
袁明羽
李振
张清清
尚政杰
付建华
王岳栩
唐家豪
郭玉杰
庞晓非
WANG Dengke;YUAN Mingyu;LI Zhen;ZHANG Qingqing;SHANG Zhengjie;FU Jianhua;WANG Yuexu;TANG Jiahao;GUO Yujie;PANG Xiaofei(State Key Laboratory Cultivation Base for Gas Geology and Gas Control,Henan Polytechnic University,Jiaozuo,454000,Henan,China;Collgeg of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo,454000,Henan,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Jiaozuo 454000,Henan,China;College of Safety and Emergency Management Engineering,Tai-yuan University of Technology,Taiyuan 030024,Shanxi,China;China Coal Technology and Engineering Group Shenyang Research Institute Co.,Ltd.,Fushun 113122,Liaoning,China;Zhengzhou Coal Industry(Group)Co.,Ltd.,Zhengzhou 450000,Henan,China)
出处
《河南理工大学学报（自然科学版）》
CAS
北大核心
2024年第2期15-25,共11页
Journal of Henan Polytechnic University（Natural Science）
基金
国家自然科学基金资助项目(52174174)
河南省高等学校重点科研项目计划基础研究专项项目(21zx004)
河南理工大学创新团队计划项目(T2022-1)
河南理工大学重点基金资助项目(NSFRF220205)。
