倾斜巷道内火灾逆流层变化规律数值模拟
|
摘要
为确定矿井火灾时期逆流层长度变化规律,给逃生与救护工作提供参考,以下行通风倾斜巷道为研究对象,建立长80 m、宽4 m、高3.5 m拱形巷道模型,通过数值模拟的方法,确定多组火灾工况下烟气逆流层的变化规律。结果表明:巷道入口端风速在0.5~3 m/s增大,烟流逆流层长度随之减小,减小幅度逐渐变缓;火源烟流放散速度在5~25 m/s增大,逆流层长度随之增大,且增加幅度逐渐变缓;入口端风速条件固定为1 m/s,巷道倾角在0°~45°增加,火源烟气放散速度小于18 m/s时,逆流层长度随巷道倾角增加而减小,火源烟气放散速度大于18 m/s时,逆流层长度随巷道倾角增加而增加。
This paper is aimed at bringing about a numerical simulation for the countercurrent fire changing regularity in the inclined tunnel with the downward ventilation as the research topic,in which we have established a 3-d tunnel model. The whole model is supposed to have the following features: its roof-radius is equal to 2 m and its length is 80 m with its width being 4 m and its height being 3. 5 m. In order to determine the variation in length of back-set bed in the mining fire process,we would like to make the model a reference for the emergency escape and rescue work by using the unstructured tetrahedron grid method to mesh the model. In addition,the said model will also be made available to take the fire source as a current fire surface at high and constant temperature while releasing the high temperature gas at a certain high speed. Technically speaking,we have set up the tunnel inlet boundary conditions,the tunnel inlet velocity boundary conditions,with the outlet being set free while conducting an analog computation by using a software named FLUENT and a standard κ- ε turbulence model. In so doing,it would be possible to discrete the control equations with the finite volume method and solve the velocity-pressure by coupling with the so-called SIMPLE method. What is more,this paper has simulated for the three different conditions: that is,the wind speed conditions of inlet is between 0. 5- 3 m / s; the fire smoke emission speed is between 5- 25 m / s,whereas the drift angle stands between 0°- 45°. At the same time,we have analysed the impact of the above said three conditions on the length of the back-set bed. From the simulation results it can be seen that the length of the back-set bed tends to decrease with the decreasing range gradually slowing down as the wind speed of the tunnel entrance increases. As the fire smoke emission speed increases,the length of back-set bed increases with the increasing range gradually slowing down. On the other hand,the length of back-set bed tends to decrease while the drift angle is increasing on the condition that the wind speed of inlet is 1 m / s,the tunnel angle increases in 0°- 45° and the fire smoke emission speed is less than 18 m / s. And,in turn,the length of back-set bed tends to increase with the increase of the drift angle on the condition that the fire smoke emission speed is greater than 18 m / s.
This paper is aimed at bringing about a numerical simulation for the countercurrent fire changing regularity in the inclined tunnel with the downward ventilation as the research topic,in which we have established a 3-d tunnel model. The whole model is supposed to have the following features: its roof-radius is equal to 2 m and its length is 80 m with its width being 4 m and its height being 3. 5 m. In order to determine the variation in length of back-set bed in the mining fire process,we would like to make the model a reference for the emergency escape and rescue work by using the unstructured tetrahedron grid method to mesh the model. In addition,the said model will also be made available to take the fire source as a current fire surface at high and constant temperature while releasing the high temperature gas at a certain high speed. Technically speaking,we have set up the tunnel inlet boundary conditions,the tunnel inlet velocity boundary conditions,with the outlet being set free while conducting an analog computation by using a software named FLUENT and a standard κ- ε turbulence model. In so doing,it would be possible to discrete the control equations with the finite volume method and solve the velocity-pressure by coupling with the so-called SIMPLE method. What is more,this paper has simulated for the three different conditions: that is,the wind speed conditions of inlet is between 0. 5- 3 m / s; the fire smoke emission speed is between 5- 25 m / s,whereas the drift angle stands between 0°- 45°. At the same time,we have analysed the impact of the above said three conditions on the length of the back-set bed. From the simulation results it can be seen that the length of the back-set bed tends to decrease with the decreasing range gradually slowing down as the wind speed of the tunnel entrance increases. As the fire smoke emission speed increases,the length of back-set bed increases with the increasing range gradually slowing down. On the other hand,the length of back-set bed tends to decrease while the drift angle is increasing on the condition that the wind speed of inlet is 1 m / s,the tunnel angle increases in 0°- 45° and the fire smoke emission speed is less than 18 m / s. And,in turn,the length of back-set bed tends to increase with the increase of the drift angle on the condition that the fire smoke emission speed is greater than 18 m / s.
引文
[1]LI Zongxiang(李宗翔),YU Jingxiao(于景晓),LIN Shukun(林树坤),et al.Fire time slips wind resistance of mine ventilation system simulation research[J].Journal of Safety and Environment(安全与环境学报),2011,11(4):172-175.
[2]WANG Wencai(王文才),QIAO Wang(乔旺),LI Gang(李刚),et al.Research of movement theory of fire smoke flow of mine roadway[J].Industry and Mine Automation(工矿自动化),2011(3):22-24.
[3]Mei Ke Institute Chongqing Branch(煤科总院重庆分院).Tunnel fire period state of ventilation[J].Coal Engineer(煤炭工程师),1992(4):1-8.
[4]ZHANG Xingkai(张兴凯).Horizontal tunnel fire smoke flow countercurrent layer formation conditions[J].Safety in Coal Mines(煤矿安全),1994(11):9-10.
[5]ZHOU Xinquan(周心权),WANG Haiyan(王海燕),ZHAO Hongze(赵红泽).Rollback law of reverse smoke flow in a horizontal airway during mine fire[J].Journal of University of Science and Technology Beijing(北京科技大学学报),2004,26(2):118-121.
[6]LI Cuiping(李翠平),DAO Zhiguo(曹志国),LI Zhongxue(李仲学),et al.3D simulation modeling techniques of fire fume spread process for underground mines[J].Journal of China Coal Society(煤炭学报),2013,38(2):257-263.
[7]ZHOU Yan(周延),WANG Xingshen(王省身).Conditions for formation of a reverse smoke flow in a horizontal tunnel[J].Journal of China Coal Society(煤炭学报),1998,23(4):362-365.
[8]XU Zhisheng(徐志胜),ZHAO Hongli(赵红莉),LI Hong(李洪),et al.Theoretical model of critical wind velocity in horizontal tunnel fires[J].Journal of Central South University:Science and Technology(中南大学学报:自然科学版),2013,44(3):1138-1143.
[9]WANG Wencai(王文才),GONG Weigang(公维刚),JIANG Yuhong(姜宇鸿),et al.Research on critical wind velocity to reverse the flow of smoke during a fire in a horizontal coal mine roadway[J].China Coal(中国煤炭),2013(7):101-104.
[10]ZHOU Fubao(周福宝),WANG Deming(王德明).Numerical analysis of backflow distance of smoke in mine fire[J].Journal of China University of Mining&Technology(中国矿业大学学报),2004,33(5):499-503.
[11]WANG Haiyan(王海燕),ZHOU Xinquan(周心权).Fire buoyant plume model and characteristic parameters of a reverse smoke in a horizontal airway during mine fire[J].Journal of China Coal Society(煤炭学报),2004,29(2):190-194.
[12]ZHOU Yan(周延),WANG Deming(王德明),ZHOU Fubao(周福宝).Experimental study on length of smoke back-flow layer of fire in horizontal tunnel[J].Journal of China University of Mining&Technology(中国矿业大学学报),2001,30(5):446-448.
[13]JIANG Juncheng(蒋军成),WANG Xingshen(王省身).Numeric analysis of smoke in roadway in mine fire[J].Journal of China Coal Society(煤炭学报),1997,22(2):165-170.
[14]WANG Gang(王刚),ZHAO Dong(赵冬).Numerical simulation on impact of induced velocity of single-point extraction system on smoke in large tunnel fire[J].Journal of Safety and Environment(安全与环境学报),2013,13(5):165-169.
[15]TAO Wenquan(陶文铨).Numerical heat transfer(数值传热学)[M].Xi'an:Xi’an Jiaotong University Press,1988:431-439.
[2]WANG Wencai(王文才),QIAO Wang(乔旺),LI Gang(李刚),et al.Research of movement theory of fire smoke flow of mine roadway[J].Industry and Mine Automation(工矿自动化),2011(3):22-24.
[3]Mei Ke Institute Chongqing Branch(煤科总院重庆分院).Tunnel fire period state of ventilation[J].Coal Engineer(煤炭工程师),1992(4):1-8.
[4]ZHANG Xingkai(张兴凯).Horizontal tunnel fire smoke flow countercurrent layer formation conditions[J].Safety in Coal Mines(煤矿安全),1994(11):9-10.
[5]ZHOU Xinquan(周心权),WANG Haiyan(王海燕),ZHAO Hongze(赵红泽).Rollback law of reverse smoke flow in a horizontal airway during mine fire[J].Journal of University of Science and Technology Beijing(北京科技大学学报),2004,26(2):118-121.
[6]LI Cuiping(李翠平),DAO Zhiguo(曹志国),LI Zhongxue(李仲学),et al.3D simulation modeling techniques of fire fume spread process for underground mines[J].Journal of China Coal Society(煤炭学报),2013,38(2):257-263.
[7]ZHOU Yan(周延),WANG Xingshen(王省身).Conditions for formation of a reverse smoke flow in a horizontal tunnel[J].Journal of China Coal Society(煤炭学报),1998,23(4):362-365.
[8]XU Zhisheng(徐志胜),ZHAO Hongli(赵红莉),LI Hong(李洪),et al.Theoretical model of critical wind velocity in horizontal tunnel fires[J].Journal of Central South University:Science and Technology(中南大学学报:自然科学版),2013,44(3):1138-1143.
[9]WANG Wencai(王文才),GONG Weigang(公维刚),JIANG Yuhong(姜宇鸿),et al.Research on critical wind velocity to reverse the flow of smoke during a fire in a horizontal coal mine roadway[J].China Coal(中国煤炭),2013(7):101-104.
[10]ZHOU Fubao(周福宝),WANG Deming(王德明).Numerical analysis of backflow distance of smoke in mine fire[J].Journal of China University of Mining&Technology(中国矿业大学学报),2004,33(5):499-503.
[11]WANG Haiyan(王海燕),ZHOU Xinquan(周心权).Fire buoyant plume model and characteristic parameters of a reverse smoke in a horizontal airway during mine fire[J].Journal of China Coal Society(煤炭学报),2004,29(2):190-194.
[12]ZHOU Yan(周延),WANG Deming(王德明),ZHOU Fubao(周福宝).Experimental study on length of smoke back-flow layer of fire in horizontal tunnel[J].Journal of China University of Mining&Technology(中国矿业大学学报),2001,30(5):446-448.
[13]JIANG Juncheng(蒋军成),WANG Xingshen(王省身).Numeric analysis of smoke in roadway in mine fire[J].Journal of China Coal Society(煤炭学报),1997,22(2):165-170.
[14]WANG Gang(王刚),ZHAO Dong(赵冬).Numerical simulation on impact of induced velocity of single-point extraction system on smoke in large tunnel fire[J].Journal of Safety and Environment(安全与环境学报),2013,13(5):165-169.
[15]TAO Wenquan(陶文铨).Numerical heat transfer(数值传热学)[M].Xi'an:Xi’an Jiaotong University Press,1988:431-439.