静电场下煤体放散瓦斯时间记忆效应研究  

Study on time memory effect of coal gas emission in electrostatic field

作　　者：王亚娟 马涛 吴鹏飞 WANG Yajuan;MA Tao;WU Pengfei(State Key Laboratory Cultivation Base for Gas Geology and Gas Control,Henan Polytechnic Universityy Jiaozuo 454000.China;Shenhua Shendong Coal Group Co.,Ltd.,Shenmu 719300,China;Doping Coal Mine,Zhengzhou Coal Industry(Group)Co.,Ltd.,Dengfeng 452470,China)

机构地区：[1]河南理工大学河南省瓦斯地质与瓦斯治理重点实验室-省部共建国家重点实验室培育基地,河南焦作454000 [2]神华神东煤炭集团有限责任公司,陕西神木719300 [3]郑州煤炭工业(集团)有限责任公司大平煤矿,河南登封452470

出　　处：《煤矿安全》2021年第10期13-18,共6页Safety in Coal Mines

基　　金：河南省科技攻关资助项目(192102310199);中国博士后科学基金第65批面上资助项目(2019M652535);河南省高校基本科研业务费专项资金资助项目(NSFRF200307)。

摘　　要：针对含瓦斯煤体在电场作用下表现出的放散初速度时间记忆效应特征,建立瓦斯放散测定实验系统,研究不同变质程度和破坏类型煤体静电场下的时间记忆效应。实验结果表明:静电场可以增大煤体瓦斯放散能力,随着加电电压的升高,瓦斯放散初速度呈先增大后减小变化趋势,并在某一特征电压下取到最大值,且构造煤相比原生结构煤特征电压较大;在连续加载8kV电压下,瓦斯放散初速度随加电时间增加呈上下波动的趋势,撤掉电场后,瓦斯放散初速度并未回落至未加电时的状态且放散速度值均高于初始状态,具有一定时间记忆效应,其中无烟煤经过电场作用后相较于未加电场在时间记忆效应内,瓦斯放散初速度增长在5%~9%之间,原生结构煤与构造煤变化量没有明显的区别;而贫煤原生结构煤在记忆效应内瓦斯放散初速度变化在5%~8%,构造煤则变化13%~18%;产生时间记忆效应的原因是一方面在静电场作用后煤体表面仍然呈现为静电状态,煤体表面电牵引力强于未加电,引起瓦斯吸附量的增大进而作用于瓦斯的放散;另一方面,在电场作用下煤体会产生激发极化电荷构成激发电场在失去电场后仍会继续影响瓦斯的放散,促进煤体瓦斯的解吸。According to the characteristics of time memory effect of initial velocity of gas bearing coal under the action of electric field, the experimental system of gas emission measurement is established to study the memory effect of different metamorphic degree and damage type of coal under electrostatic field. The experimental results show that the electrostatic field can increase the gas emission capacity of coal. With the increase of voltage, the initial gas emission speed increases first and then decreases, and reaches the maximum value under a certain characteristic voltage and the characteristic voltage of structural coal is larger than that of primary structural coal. Under the continuous load of 8 kV, the initial gas emission speed fluctuates up and down with the power on time, and the power is removed. After the field, the initial velocity of gas emission does not fall back to the state without power on, and the value of gas emission velocity is higher than the initial state, which has a certain time memory effect. The initial velocity of gas emission increases between 5% and 9% for anthracite coal after the electric field effect compared with that without electric field, and there is no obvious difference between the change of primary structural coal and structural coal;however, it is poor in the memory effect, the initial velocity of gas emission of coal with primary structure changes in 5%-8%,while that of structural coal changes in 13%-18%. The reason of time memory effect is that on the one hand, the coal surface is still in electrostatic state after the electrostatic field, and the electric traction force on the coal surface is stronger than that without power on, which causes the increase of gas adsorption and then acts on the gas emission;on the other hand, under the electric field, the coal will generate induced polarization charge to form the excitation electric field, which will continue to affect the gas emission after the loss of electric field to promote the desorption of coal gas.

关 键 词：煤体瓦斯 静电场 记忆效应 放散初速度 特征电压 

分 类 号：TD713[矿业工程—矿井通风与安全]