超声空化诱导煤微观孔隙损伤的原位测试技术研究  

Study on in-situ testing technology for microscopic pore damage in coal induced by ultrasonic cavitation

作　　者：李傲 王玉娟 郭晓阳 邓存宝 李岩峰 徐家骅 LI Ao;WANG Yujuan;GUO Xiaoyang;DENG Cunbao;LI Yanfeng;XU Jiahua(School of Safety and Emergency Management Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Postdoctoral Workstation,Jinneng Coal Industry Group Co.,Ltd.,Datong 037000,China)

机构地区：[1]太原理工大学安全与应急管理工程学院,山西太原030024 [2]晋能控股煤业集团有限公司博士后工作站,山西大同037000

出　　处：《实验技术与管理》2024年第8期30-35,共6页Experimental Technology and Management

基　　金：博士后联合资助项目(275226);国家自然科学基金青年项目(52204231);山西省基础研究计划项目(20210302124483)。

摘　　要：为促进超声波激励煤层瓦斯促抽技术的实际应用,深入探索超声空化损伤煤孔隙的科学内涵,该实验借助自主研发的煤孔隙超声空化损伤致裂实验系统和原位X射线纳米CT扫描技术,测试不同超声空化条件下煤孔隙结构变化,研究煤微观孔隙系统损伤的超声空化诱导机理。实验结果表明:超声空化效应能够使狭缝孔隙形态向球型转变(转变率超20%),有效改善煤微观孔隙空间结构,连通孔隙团体积能得到提升。此外,超声空化效应能增加直径小于6 nm的喉道尺寸,主要诱导原始小尺寸孤立孔隙与连通孔隙团沟通,还可诱导非连通微观孔隙相互连接,以增强煤微观孔隙拓扑结构。超声空化对于提升煤体渗透性和促进瓦斯抽采具有很大的实际应用价值。[Objective]The existing research on ultrasonic stimulation of coal seam gas extraction remains limited to the realms of thermal and vibrational effects,lacking a scientific understanding of ultrasonic cavitation damage to coal pores,leading to an incomplete theoretical framework.Therefore,there is a need to promote the practical application of ultrasonic-induced coal seam gas extraction technology and to conduct an in-depth exploration of the scientific connotation of ultrasonic cavitation damage to coal pores.A self-developed ultrasonic cavitation damage cracking experimental system for coal pores and in-situ X-ray nano-CT scanning technology were utilized in this experiment to investigate the changes in coal pore structure under varying ultrasonic cavitation conditions and explore the mechanism behind the ultrasonic cavitation damage induced on the microscopic pore system of coal.[Methods]This study utilizes Phoenix v|tome|x s,a multifunctional high-resolution nano-CT scanner,for the detection of coal pore structure damage.Equipped with state-of-the-art nano-X-ray tubes,this instrument demonstrates exceptional resolution capability,enabling clear visualization of microstructural defects and accurate acquisition of internal structure and topography information.Moreover,it facilitates precise,three-dimensional analysis.[Results]Regarding the comparison of the CT scanning results of the same sample before and after treatment,small scanning position errors lead to significant differences in the results,making it impossible to accurately compare and analyze the pore reconstruction results before and after treatment.To solve this experimental technical problem of structural comparison distortion caused by scanning position errors,the coal sample is firmly fixed on the carrier needle throughout the ultrasonic cavitation treatment process to ensure in-situ observation of the pore microstructure.Second,during the untreated CT scan of the coal sample using ultrasound,the fixed sample is loaded onto the rotating sample ho

关 键 词：超声空化 煤微观孔隙 无损检测 原位测试 孔隙损伤 

分 类 号：TU45[建筑科学—岩土工程]