低瓦斯矿井封闭采空区“呼吸”现象特征及防控技术
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摘要
低瓦斯矿井停采工作面进行封闭处理后,大量游离瓦斯会集聚在封闭空间内。当密闭质量下降到一定程度时,采空区外界空气压力的波动会引发封闭采空区"呼吸"现象,该现象会使密闭外侧存在瓦斯超限的安全隐患。以正利煤矿14-1103封闭采空区为研究对象,分析了不同大气参数条件下封闭采空区内、外气压以及密闭外侧瓦斯体积分数的变化规律。运用通风能量方程和理想气体状态方程分析了"呼吸"现象的产生机理,结合达西定律得到了密闭内外压差与密闭外瓦斯体积分数的关系表达式。结果表明,封闭采空区"呼吸"现象的产生是地面大气参数、井巷风流参数、井巷特征和采空区内气体状态参数综合作用的结果;在密闭内外压差的持续作用下,封闭采空区会与外界产生气体交换,当压差分别为正值和负值时,采空区内气体压力分别呈逐渐降低和逐渐升高趋势;封闭采空区内气压变化幅度很小,密闭内外压差产生正负交替的主导因素为密闭外空气静压的波动;当井巷特征和井巷风量稳定时,密闭外侧空气静压的变化趋势与地面大气压相似,与地面大气温度相反;在密闭渗透率和密闭外侧风量比较稳定的前提下,密闭内外压差为正值时,密闭外瓦斯浓度与密闭内外压差呈正相关关系,两者的变化趋势相似。为了预防密闭外侧瓦斯超限,设计了由监测信号采集子系统、现场自动控制子系统和管道抑爆子系统组成的瓦斯释放自动监测调控系统,确定了基于压差阈值和瓦斯浓度阈值的联合调控准则,提出了阀门开度的分级调控逻辑思路。
After the mining face of low-gas mine is sealed,a large number of free gas gathers in the sealed space.When the quality of the seal drops to a certain extent,the fluctuation of the air pressure out of the sealed goaf will cause"breathing"phenomenon and lead to the gas concentration of the seal's outside exceed safety limit.No.14-1103 sealed goaf of Zhengli Coalmine is selected as the research object,the variation law on inner and outer pressure of sealed goaf and gas concentration of the seal's outside are analyzed under different atmospheric parameters. The mechanism of"breathing"phenomenon is theoretically analyzed with ventilation energy equation and state equation of ideal gas,and the expression of relationship between differential pressure and gas concentration is obtained with Darcy law. The results show that,"breathing"phenomenon results from the combining action of ground atmospheric parameters,airflow parameters,roadway characteristics and gas state parameters of sealed goaf.Under the continuous action of differential pressure between seal's inside and outside,gas exchange will occur between sealed goaf and outside space. The gas pressure in sealed goaf is gradually decreasing or increasing as the differential pressure is positive or negative.The gas pressure in sealed goaf has small change,the fluctuation of static pressure of the seal's outside is the dominant factor that results in positive and negative alternation of differential pressure.The variation trend of the static pressure of the seal's outside is similar to that of the ground atmospheric pressure and opposite to that of the ground atmospheric temperature when roadway characteristics and air quantity are stable.On the premise that the seal's permeability and the air quantity of seal's outside are relatively stable,the gas concentration is positively correlated with the differential pressure when the positive differential pressure appears,so that,the change trend of gas concentration is similar to that of differential pressure.An automatic control system of gas release,which consists of monitoring signal acquisition subsystem,field automatic control subsystem and pipeline explosion suppression subsystem,is designed to prevent gas concentration of seal's outside from exceeding safety limit.The joint control criteria is determined based on the threshold values of differential pressure and gas concentration,and the grading control logic of valve opening is put forward.
After the mining face of low-gas mine is sealed,a large number of free gas gathers in the sealed space.When the quality of the seal drops to a certain extent,the fluctuation of the air pressure out of the sealed goaf will cause"breathing"phenomenon and lead to the gas concentration of the seal's outside exceed safety limit.No.14-1103 sealed goaf of Zhengli Coalmine is selected as the research object,the variation law on inner and outer pressure of sealed goaf and gas concentration of the seal's outside are analyzed under different atmospheric parameters. The mechanism of"breathing"phenomenon is theoretically analyzed with ventilation energy equation and state equation of ideal gas,and the expression of relationship between differential pressure and gas concentration is obtained with Darcy law. The results show that,"breathing"phenomenon results from the combining action of ground atmospheric parameters,airflow parameters,roadway characteristics and gas state parameters of sealed goaf.Under the continuous action of differential pressure between seal's inside and outside,gas exchange will occur between sealed goaf and outside space. The gas pressure in sealed goaf is gradually decreasing or increasing as the differential pressure is positive or negative.The gas pressure in sealed goaf has small change,the fluctuation of static pressure of the seal's outside is the dominant factor that results in positive and negative alternation of differential pressure.The variation trend of the static pressure of the seal's outside is similar to that of the ground atmospheric pressure and opposite to that of the ground atmospheric temperature when roadway characteristics and air quantity are stable.On the premise that the seal's permeability and the air quantity of seal's outside are relatively stable,the gas concentration is positively correlated with the differential pressure when the positive differential pressure appears,so that,the change trend of gas concentration is similar to that of differential pressure.An automatic control system of gas release,which consists of monitoring signal acquisition subsystem,field automatic control subsystem and pipeline explosion suppression subsystem,is designed to prevent gas concentration of seal's outside from exceeding safety limit.The joint control criteria is determined based on the threshold values of differential pressure and gas concentration,and the grading control logic of valve opening is put forward.
引文
[1]周福宝,王德明,陈开岩.矿井通风与空气调节[M].徐州:中国矿业大学出版社,2008.
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[10]孙希奎,刘金举.自燃煤层封闭采空区瓦斯火灾双重灾害治理技术[J].煤炭科学技术,2014,42(6):100-103.SUN Xikui,LIU Jinju.Gas and fire dual disaster control technology in sealed goaf with spontaneous combustion seam[J].Coal Science and Technology,2014,42(6):100-103.
[11]宋来智,杨广文,段西凯.封闭采空区气体波动的原因与治理研究[J].煤矿安全,2015,46(5):143-145.SONG Laizhi,YANG Guangwen,DUAN Xikai. Reason and governance of gas fluctuation in closed goaf[J]. Safety in Coal Mines,2015,46(5):143-145.
[12]朱帅虎,王金宝.综采面邻空煤柱漏风微循环现象研究[J].河北工程大学学报(自然科学版),2016,33(3):85-88.ZHU Shuaihu,WANG Jinbao.Research on air leakage micro-circulation in coal pillar near goaf for comprehensive mechanical mining face[J].Journal of Hebei University of Engineering(Natural Science Edition),2016,33(3):85-88.
[13]郭翔.采空区呼吸现象原因分析及瓦斯治理技术研究[J].能源技术与管理,2016,41(4):24-26.
[14]王玉怀,刘二小,侯斐,等.大采高超长工作面停采线附近采空区气体监测及漏风防治[J].中国煤炭,2017,43(2):100-103.WANG Yuhuai,LIU Erxiao,HOU Fei,et al. Gas monitoring and leakage prevention at gob near stop line of large mining height long caving mining face[J].China Coal,2017,43(2):100-103.
[15]褚廷湘,姜德义,余明高,等.顶板巷瓦斯抽采诱导煤自燃机制及安全抽采量研究[J].煤炭学报,2016,41(7):1701-1710.CHU Tingxiang,JIANG Deyi,YU Minggao,et al. Study on mechanism of inducing coal spontaneous combustion and safe gas extraction volume under roof tunnel gas extraction[J]. Journal of China Coal Society,2016,41(7):1701-1710.
[16]杨胜强,秦毅,孙家伟,等.高瓦斯易自燃煤层瓦斯与自燃复合致灾机理研究[J].煤炭学报,2014,39(6):1094-1101.YANG Shengqiang,QIN Yi,SUN Jiawei,et al. Research on coupling hazard mechanism of mine gas and coal fire for a gassy and high spontaneous combustion propensity coal seam[J].Journal of China Coal Society,2014,39(6):1094-1101.
[17]秦波涛,张雷林,王德明,等.采空区煤自燃引爆瓦斯的机理及控制技术[J].煤炭学报,2009,34(12):1655-1659.QIN Botao,ZHANG Leilin,WANG Deming,et al. Mechanism and restraining technology on spontaneous combustion of coal detonating gas in goaf[J].Journal of China Coal Society,2009,34(12):1655-1659.
[18]秦伟,许家林,胡国忠,等.老采空区瓦斯储量预测方法研究[J].煤炭学报,2013,38(6):948-953.QIN Wei,XU Jialin,HU Guozhong,et al.Study on computing method of old goaf methane reserves[J].Journal of China Coal Society,2013,38(6):948-953.
[19]张春华,张敏,王继仁.基于正压控制的采空区双重高效密封防火技术[J].煤炭学报,2015,40(7):1569-1573.ZHANG Chunhua,ZHANG Min,WANG Jiren. Dual effective sealing technology for goaf fire prevention based on positive pressure control method[J]. Journal of China Coal Society,2015,40(7):1569-1573.
[20] FAUCONNIER C J. Fluctuations in barometric pressure as a contributory factor to gas explosions in South African mines[J].Journal of the Southern African Institute of Mining and Metallurgy,1992,92(5):131-147.
[21]刘忠华,刘辉,戴月升.浅析低瓦斯矿井瓦斯涌出的原因及防治措施[J].煤矿安全,1998(6):12-14.
[22]霍忠锋,刘波,王玉怀,等.察哈素煤矿3101工作面及地表漏风联合测试及其防治[J].煤矿安全,2015,46(3):130-132.HUO Zhongfeng,LIU Bo,WANG Yuhuai,et al. Joint test for air leakage of 3101 working face and surface in Chahasu coal mine and its control[J].Safety in Coal Mines,2015,46(3):130-132.
[23]李鹏,秦清河.补连塔煤矿22307工作面疏放水期间火灾防治技术[J].煤矿安全,2017,48(3):129-132.LI Peng,QIN Qinghe. Fire preventing and extinguishing technology during draining water at 22307 face of Bulianta coal mine[J].Safety in Coal Mines,2017,48(3):129-132.
[24]关万里,程健维.矿井密闭空间内气体浓度变化模型及其模拟分析[J].矿业安全与环保,2013,40(5):91-95.GUAN Wanli,CHENG Jianwei. Variation model and simulation analysis of gas compositions in a sealed space of mine[J]. Mining Safety&Environmental Protection,2013,40(5):91-95.
[25]张国枢.通风安全学(第2版)[M].徐州:中国矿业大学出版社,2011.
[26] SAMUEL A L.Computational modeling of barometric pressure fluctuation effects on explosive methane-air mixtures in a longwall mine gob[D]. Colorado:Colorado School of Mines,2017:39-44.
[27] SAMUEL A L,JRGEN F B,GREGORY E B,et al.Computational fluid dynamics simulation on the longwall gob breathing[J]. International Journal of Mining Science and Technology,2017,27(2):185-189.
[28]张江石,李志伟,安宇,等.矿井气压变化和瓦斯涌出的关系分析与实证研究[J].煤矿安全,2009,40(9):83-85.
[29]叶汝陵.矿井通风压力变化与瓦斯涌出量的关系[J].矿业安全与环保,1983(2):28-35.
[30]国家安全生产监督管理总局,国家煤矿安全监察局.煤矿安全规程[M].北京:煤炭工业出版社,2016.
[2]李作泉.大气压变化影响采空区瓦斯异常涌出的原因分析与防治技术[J].煤矿安全,2006,37(11):14-16.LI Zuoquan.Analyze the influence of the air pressure changes to the unusual gas emission phenomenon in gob and discuss the preventing technology[J].Safety in Coal Mines,2006,37(11):14-16.
[3]李迎军,刘家伟.低瓦斯矿井瓦斯异常涌出规律分析与综合治理技术[A].2008年煤矿瓦斯治理与减排技术研讨会论文集[C].徐州:中国矿业大学出版社,2009:9-14.
[4]陈世杰.红旗煤矿采空区瓦斯涌出原因及其治理[J].煤矿安全,2005,36(1):56-57.
[5]吕昭双.苇湖梁煤矿井下密闭观测结果及认识[J].煤矿安全,1987(11):14-18.
[6]王昌斌,薄其山,杨绪金,等.采空区喘息现象浅析[J].煤矿安全,2005,36(10):38-39.
[7]褚成军.采空区优化封闭预防瓦斯超限关键技术[A].安徽省煤炭学会第六通风安全专业学术研讨会论文集[C].淮南:安徽理工大学学术出版中心,2011:107-110.
[8]刘峰,梁蹦,刘涛.采空区封闭瓦斯泄漏原因及治理技术[A].煤炭开采新理论与新技术-中国煤炭学会开采专业委员会2012年学术年会论文集[C].徐州:中国矿业大学出版社,2012:367-370.
[9]刘虎生,张运增.大气压变化影响回风隅角氧气浓度异常变化的原因分析及防治技术[J].煤炭技术,2014,33(9):38-41.LIU Husheng,ZHANG Yunzeng. Reasons brief analysis of effect of change in atmospheric pressure on change in abnormal oxygen concentration in return air corner and preventing techniques[J].Coal Technology,2014,33(9):38-41.
[10]孙希奎,刘金举.自燃煤层封闭采空区瓦斯火灾双重灾害治理技术[J].煤炭科学技术,2014,42(6):100-103.SUN Xikui,LIU Jinju.Gas and fire dual disaster control technology in sealed goaf with spontaneous combustion seam[J].Coal Science and Technology,2014,42(6):100-103.
[11]宋来智,杨广文,段西凯.封闭采空区气体波动的原因与治理研究[J].煤矿安全,2015,46(5):143-145.SONG Laizhi,YANG Guangwen,DUAN Xikai. Reason and governance of gas fluctuation in closed goaf[J]. Safety in Coal Mines,2015,46(5):143-145.
[12]朱帅虎,王金宝.综采面邻空煤柱漏风微循环现象研究[J].河北工程大学学报(自然科学版),2016,33(3):85-88.ZHU Shuaihu,WANG Jinbao.Research on air leakage micro-circulation in coal pillar near goaf for comprehensive mechanical mining face[J].Journal of Hebei University of Engineering(Natural Science Edition),2016,33(3):85-88.
[13]郭翔.采空区呼吸现象原因分析及瓦斯治理技术研究[J].能源技术与管理,2016,41(4):24-26.
[14]王玉怀,刘二小,侯斐,等.大采高超长工作面停采线附近采空区气体监测及漏风防治[J].中国煤炭,2017,43(2):100-103.WANG Yuhuai,LIU Erxiao,HOU Fei,et al. Gas monitoring and leakage prevention at gob near stop line of large mining height long caving mining face[J].China Coal,2017,43(2):100-103.
[15]褚廷湘,姜德义,余明高,等.顶板巷瓦斯抽采诱导煤自燃机制及安全抽采量研究[J].煤炭学报,2016,41(7):1701-1710.CHU Tingxiang,JIANG Deyi,YU Minggao,et al. Study on mechanism of inducing coal spontaneous combustion and safe gas extraction volume under roof tunnel gas extraction[J]. Journal of China Coal Society,2016,41(7):1701-1710.
[16]杨胜强,秦毅,孙家伟,等.高瓦斯易自燃煤层瓦斯与自燃复合致灾机理研究[J].煤炭学报,2014,39(6):1094-1101.YANG Shengqiang,QIN Yi,SUN Jiawei,et al. Research on coupling hazard mechanism of mine gas and coal fire for a gassy and high spontaneous combustion propensity coal seam[J].Journal of China Coal Society,2014,39(6):1094-1101.
[17]秦波涛,张雷林,王德明,等.采空区煤自燃引爆瓦斯的机理及控制技术[J].煤炭学报,2009,34(12):1655-1659.QIN Botao,ZHANG Leilin,WANG Deming,et al. Mechanism and restraining technology on spontaneous combustion of coal detonating gas in goaf[J].Journal of China Coal Society,2009,34(12):1655-1659.
[18]秦伟,许家林,胡国忠,等.老采空区瓦斯储量预测方法研究[J].煤炭学报,2013,38(6):948-953.QIN Wei,XU Jialin,HU Guozhong,et al.Study on computing method of old goaf methane reserves[J].Journal of China Coal Society,2013,38(6):948-953.
[19]张春华,张敏,王继仁.基于正压控制的采空区双重高效密封防火技术[J].煤炭学报,2015,40(7):1569-1573.ZHANG Chunhua,ZHANG Min,WANG Jiren. Dual effective sealing technology for goaf fire prevention based on positive pressure control method[J]. Journal of China Coal Society,2015,40(7):1569-1573.
[20] FAUCONNIER C J. Fluctuations in barometric pressure as a contributory factor to gas explosions in South African mines[J].Journal of the Southern African Institute of Mining and Metallurgy,1992,92(5):131-147.
[21]刘忠华,刘辉,戴月升.浅析低瓦斯矿井瓦斯涌出的原因及防治措施[J].煤矿安全,1998(6):12-14.
[22]霍忠锋,刘波,王玉怀,等.察哈素煤矿3101工作面及地表漏风联合测试及其防治[J].煤矿安全,2015,46(3):130-132.HUO Zhongfeng,LIU Bo,WANG Yuhuai,et al. Joint test for air leakage of 3101 working face and surface in Chahasu coal mine and its control[J].Safety in Coal Mines,2015,46(3):130-132.
[23]李鹏,秦清河.补连塔煤矿22307工作面疏放水期间火灾防治技术[J].煤矿安全,2017,48(3):129-132.LI Peng,QIN Qinghe. Fire preventing and extinguishing technology during draining water at 22307 face of Bulianta coal mine[J].Safety in Coal Mines,2017,48(3):129-132.
[24]关万里,程健维.矿井密闭空间内气体浓度变化模型及其模拟分析[J].矿业安全与环保,2013,40(5):91-95.GUAN Wanli,CHENG Jianwei. Variation model and simulation analysis of gas compositions in a sealed space of mine[J]. Mining Safety&Environmental Protection,2013,40(5):91-95.
[25]张国枢.通风安全学(第2版)[M].徐州:中国矿业大学出版社,2011.
[26] SAMUEL A L.Computational modeling of barometric pressure fluctuation effects on explosive methane-air mixtures in a longwall mine gob[D]. Colorado:Colorado School of Mines,2017:39-44.
[27] SAMUEL A L,JRGEN F B,GREGORY E B,et al.Computational fluid dynamics simulation on the longwall gob breathing[J]. International Journal of Mining Science and Technology,2017,27(2):185-189.
[28]张江石,李志伟,安宇,等.矿井气压变化和瓦斯涌出的关系分析与实证研究[J].煤矿安全,2009,40(9):83-85.
[29]叶汝陵.矿井通风压力变化与瓦斯涌出量的关系[J].矿业安全与环保,1983(2):28-35.
[30]国家安全生产监督管理总局,国家煤矿安全监察局.煤矿安全规程[M].北京:煤炭工业出版社,2016.