摘要
由于对煤与瓦斯突出激发后致灾特征及其诱导矿井风流灾变机制不清,现场常根据经验布设风门、布置自救系统等设施,尚不能有效地布置安全防护措施和制定科学合理的应急预案。为了准确掌握突出冲击动力效应及致灾特征,基于相似理论,研发了一套考虑突出孔洞周围卸压区煤体瓦斯补给作用的突出模拟实验系统,并基于突出模型和瓦斯渗流理论通过严格计算确定了补气装置的关键参数。该实验系统主要包括:突出孔洞动力系统、突出激发装置、巷道模拟系统和数据采集与控制中心4个模块,能够模拟巷道内突出冲击波形成和传播、突出煤-瓦斯两相流运移及瓦斯逆流等突出动力现象。开展了瓦斯压力为0.8 MPa的突出灾变模拟实验,利用高速摄像机直接观测到突出冲击波形成过程。结果表明:突出发生瞬间,在管道内瞬间形成空气冲击波,后面依次出现的是冲击气流、突出瓦斯气流和煤-瓦斯两相流。且空气冲击波速度>冲击气流速度>突出瓦斯气流速度>突出煤-瓦斯两相流阵面速度,4者最大速度分别为546.5、496.7、112.6、51.5 m/s,并沿管道逐渐衰减。突出过程中高压瓦斯从突出孔洞涌入巷道空间,造成瓦斯逆流现象。突出过程中突出孔洞内瓦斯压力呈指数下降。突出发生后巷道内瓦斯体积分数随时间变化存在“骤升期”和“缓慢下降期”,突出瓦斯在巷道内运移方式主要包括“驱替”和“扩散”。突出煤沿主巷堆积高度与堆积质量呈现出一致性。突出煤与原煤粒径分布差异主要集中于0~500μm,而粒径分布最大差异主要集中于150~200μm。此外,粒径分布于150~200μm的煤粉占比随距突出口距离的增加而增加,表现出较强的分选性。
As the disaster-causing characteristics of coal and gas outburst and the mechanism of induced mine airflow disaster are not clear,the facilities such as air door and self-rescue system are often arranged on site according to miner’s experience,thus it is difficult to take safety protection measures and formulate scientific and reasonable emergency plan.In order to accurately grasp the impact dynamic effect and disaster-causing characteristics of coal and gas outburst,based on the similarity theory,a set of physical simulation experimental system considering the disaster-causing strengthening effect caused by gas in the pressure relief area around the outburst hole was developed.And the key parameters of the gas supplement device were determined through strict calculation based on the outburst model and gas seepage theory.The experimental system mainly includes outburst hole dynamic system,outburst excitation device,roadway simulation system and data acquisition and control center,which can simulate outburst dynamic phenomena such as the formation and propagation of outburst shock wave,the migration of outburst coal-gas two-phase flow and gas countercurrent in the simulated roadway.The simulation experiment of outburst disaster with a gas pressure of 0.8 MPa was carried out.And the forming process of outburst shock wave was directly observed with a high-speed camera.The results show that the outburst shock wave is formed instantly in the pipeline at the moment of outburst,followed by impact flow,outburst gas flow and coal-gas two-phase flow.The comparable velocities of each parameter are in the order:the air shock wave velocity>impact flow velocity>outburst gas-flow velocity>outburst coal-gas two-phase flow front velocity.The maximum velocities of each parameter are 546.5,496.7,112.6 and 51.5 m/s respectively,and gradually decay along the pipeline.At the moment of outburst,high-pressure gas poured into the roadway space from the outburst hole,resulting in gas reflux.During the outburst process,the gas pressure inside the outburst hole decreases exponentially.After the outburst occurs,the gas concentration in the roadway changes with time in“sudden rise stage”and“slow decline stage”,and the migration mode of the gas outburst in the roadway mainly includes“displacement”and“diffusion”.The accumulation height and quality of outburst coal along the main roadway are consistent.The difference of grain size distribution between outburst coal and raw coal is mainly concentrated in 0-500μm,while the difference of maximum grain size distribution is mainly concentrated in 150-200μm.In addition,the proportion of coal powder with particle size distribution in the range of 150-200μm increases with the increase of the distance from the outburst mouth,showing a strong sorting ability.
作者
杨雪林
文光才
孙海涛
曹偈
王波
戴林超
鲁俊
YANG Xuelin;WEN Guangcai;SUN Haitao;CAO Jie;WANG Bo;DAI Linchao;LU Jun(School of Safety and Emergency Management Engineering,Taiyuan University of Technology,Taiyuan 030024,China;State Key Laboratory of the Gas Disaster Detecting Preventing and Emergency Controling,Chongqing 400037,China;Gas Research Branch,Chongging Research Institute,China Coal Technology Engineering Group,Chongging 400037,China;Institute of Deep Earth Sciences and Green Energy,Shenzhen University,Shenzhen518000,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2023年第10期3731-3749,共19页
Journal of China Coal Society
基金
国家自然科学基金资助项目(51874348)
瓦斯灾害监控与应急技术国家重点实验室开放基金资助项目(2021SKLKF05)
中国博士后基金资助项目(2021M692192)。
关键词
煤与瓦斯突出
煤-瓦斯两相流
突出冲击波
瓦斯涌出
突出强度
coal and gas outburst
coal-gas two phase flow
outburst shock wave
gas emission
outburst intensity
