矿井火灾火源燃烧特性及其对下风向巷道影响的研究
发布时间：2018-08-11 08:39
【摘要】：矿井巷道发生火灾后，由于受巷道空间相对狭窄、封闭以及氧气供应不足等特点的影响，往往会造成重大人身财产损失。因此，针对矿井巷道火灾，研究火源燃烧特性、火区阻力以及火源燃烧过程中对下风向巷道的影响，对于合理评价火灾危险性、科学分析火区条件下通风系统可靠性、矿井火灾救援时合理控制风流方向以及随时掌握烟流流经巷道温度和风量，均具有重要的理论与现实意义。 （1）本文通过相似实验模型实验测定了各测点的风流动压和温度，火区前后测点的静压差和下风向的烟气组分；对基于氧消耗原理的火源热释放速率方程，火源下风向巷道的温度场方程以及火区阻力方程进行了深入理论研究并确定了计算方法；确定了火源燃烧过程中不同时刻的火源热释放速率、火区阻力以及温度场分布。 （2）分析了火源燃烧过程不同时刻的热释放速率，得出其变化过程要经历三个阶段，首先是快速发展阶段，该阶段火源迅速达到最大热释放速率；其次是稳定阶段，该阶段火源以最大热释放速率燃烧，持续时间大于发展阶段但小于衰减阶段；最后是缓慢衰减阶段，该阶段火源热释放速率随时间推移逐渐下降，持续时间大约占整个燃烧过程的2/3；正常通风情况下火源最大热释放速率和通风动压之间存在一次方程关系，煤和坑木分别为Q_(max)=0.0035H_v+0.0175和Q_(max)=0.0039H_v+0.06。 （3）据火源热释放速率t~2模型理论分析了热释放速率计算结果，得到了煤和坑木燃烧过程热释放速率t~2模型，煤的发展系数和衰减系数分别为12kW/min~2和0.12kW/min~2，坑木分别为12kW/min~2和2.2kW/min~2。对火源热释放速率t~2模型积分运算，建立了火源总放热量方程，总放热量除以煤的质量即为单位质量煤的放热量，计算得到单位质量煤和坑木的放热量分别为432kJ和1658kJ。 （4）实验确定了温度场方程实验系数Kc，即在火灾发展阶段Kc=15～20，在火灾的稳定阶段Kc=10～15，在火灾的衰减阶段Kc=20～25。研究了断面温度t~2模型理论，建立断面3温度变化t~2模型，其发展系数和衰减系数分别为0.251K/min~2和0.0708K/min~2。 （5）对火区下风向温度场变化规律分析表明，在矿井巷道火灾的发展和稳定阶段，下风向巷道中风流的温度随着距火区距离的增大而呈下降趋势。在火灾的衰减阶段，由于火源不稳定和新鲜风流的流入，下风向巷道中有一个温度下降最快区段，，这个区段首先从靠近火灾区开始，然后逐渐向下风向巷道的远处移动。 （6）对火源总阻力和火区阻力变化规律分析得出，巷道中火源在燃烧过程中，其总阻力由正面阻力、摩擦阻力和火区阻力构成；正面阻力随着燃烧物体积的减小而逐渐减少，摩擦阻力保持不变；火区阻力在发展和稳定燃烧阶段逐渐增大，在衰减阶段开始降低并趋向于零；火区阻力在风流温度增高到351.6K、巷道风量为0.419m3/s时，达到最大值71.5Pa。
[Abstract]:After the mine roadway fire, due to the relatively narrow space, closed and lack of oxygen supply and other characteristics, it will often cause significant loss of life and property. Therefore, in view of the mine tunnel fire, the characteristics of fire source combustion, the resistance of fire area and the influence of fire source combustion on the downwind tunnel are studied, and the reliability of ventilation system under fire zone condition is scientifically analyzed for evaluating the fire risk reasonably, and analyzing the reliability of ventilation system under the condition of fire area scientifically. In mine fire rescue, the direction of air flow should be controlled reasonably and the temperature and volume of air flowing through the roadway should be grasped at any time. All of them have important theoretical and practical significance. (1) in this paper, the wind flow pressure and temperature at each measuring point, the static pressure difference between the points before and after the fire and the smoke components of the downwind direction are measured by similar experimental model. The heat release rate equation of fire source based on oxygen consumption principle, the temperature field equation of wind tunnel under fire source and the resistance equation of fire zone are studied theoretically and the calculation method is determined. The heat release rate of fire source at different time, the resistance of fire area and the distribution of temperature field are determined. (2) the heat release rate at different time in the process of fire source combustion is analyzed, and it is found that the heat release rate of fire source combustion process goes through three stages. The first stage is the rapid development stage, the fire source rapidly reaches the maximum heat release rate, the second stage is the stable stage, the fire source burns at the maximum heat release rate, the duration is longer than the development stage, but less than the attenuation stage. Finally, the slow decay stage, in which the heat release rate of the fire source decreases gradually with the passage of time, accounts for about 2 / 3 of the whole combustion process. Under normal ventilation, there is a first order equation between the maximum heat release rate of fire source and the dynamic pressure of ventilation. The coal and pit wood are Q _ (max) _ 0. 0035 HV _ v 0.0175 and Q _ (max) _ (max) _ 0. 0039 Hv / v 0.06 respectively. (3) the calculation results of heat release rate are analyzed according to the fire source heat release rate t ~ 2 model. The thermal release rate t ~ (2) model of coal and pit wood combustion is obtained. The development coefficient and attenuation coefficient of coal are 12kW/min~2 and 0.12 kW / min ~ (-2), and 12kW/min~2 and 2.2 kW / min ~ (2), respectively. Based on the integral calculation of the heat release rate t ~ 2 model of the fire source, the total heat release equation of the fire source is established. The total heat emission is divided by the mass of the coal as the heat release of the coal per unit mass. The heat release of unit mass coal and pit wood is calculated to be 432kJ and 1658kJ respectively. (4) the experimental coefficient of temperature field equation Kc is determined by experiments, that is, in the development stage of the fire, in the stable stage of the fire, and in the attenuation stage of the fire, the experimental coefficient of the temperature field equation is Kc. The theory of section temperature t _ 2 model is studied, and the model of section 3 temperature variation t _ 2 is established. The development coefficient and attenuation coefficient are 0.251K/min~2 and 0.0708K / min ~ (2), respectively. (5) the analysis of the variation law of wind direction temperature field under fire zone shows that, In the development and stabilization stage of mine roadway fire, the temperature of air flow in the downwind roadway decreases with the increase of the distance from the fire area. At the attenuation stage of the fire, due to the unstable source of the fire and the inflow of fresh wind flow, there is a section of the downwind roadway in which the temperature drops fastest, which begins near the fire zone. Then it gradually moves down to the distance of the roadway. (6) the total resistance of the fire source and the resistance of the fire zone are analyzed. It is concluded that the total resistance of the fire source in the roadway is composed of the positive resistance, the friction resistance and the resistance in the fire zone. The positive resistance decreases gradually with the decrease of the volume of the combustion material, and the friction resistance remains unchanged, and the resistance in the fire zone increases gradually in the development and steady combustion stage, then decreases and tends to zero at the attenuation stage. The maximum value of resistance in fire zone is 71.5 Pa. when the air flow temperature increases to 351.6 K and the air volume of roadway is 0.419m3/s.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TD752
[Abstract]:After the mine roadway fire, due to the relatively narrow space, closed and lack of oxygen supply and other characteristics, it will often cause significant loss of life and property. Therefore, in view of the mine tunnel fire, the characteristics of fire source combustion, the resistance of fire area and the influence of fire source combustion on the downwind tunnel are studied, and the reliability of ventilation system under fire zone condition is scientifically analyzed for evaluating the fire risk reasonably, and analyzing the reliability of ventilation system under the condition of fire area scientifically. In mine fire rescue, the direction of air flow should be controlled reasonably and the temperature and volume of air flowing through the roadway should be grasped at any time. All of them have important theoretical and practical significance. (1) in this paper, the wind flow pressure and temperature at each measuring point, the static pressure difference between the points before and after the fire and the smoke components of the downwind direction are measured by similar experimental model. The heat release rate equation of fire source based on oxygen consumption principle, the temperature field equation of wind tunnel under fire source and the resistance equation of fire zone are studied theoretically and the calculation method is determined. The heat release rate of fire source at different time, the resistance of fire area and the distribution of temperature field are determined. (2) the heat release rate at different time in the process of fire source combustion is analyzed, and it is found that the heat release rate of fire source combustion process goes through three stages. The first stage is the rapid development stage, the fire source rapidly reaches the maximum heat release rate, the second stage is the stable stage, the fire source burns at the maximum heat release rate, the duration is longer than the development stage, but less than the attenuation stage. Finally, the slow decay stage, in which the heat release rate of the fire source decreases gradually with the passage of time, accounts for about 2 / 3 of the whole combustion process. Under normal ventilation, there is a first order equation between the maximum heat release rate of fire source and the dynamic pressure of ventilation. The coal and pit wood are Q _ (max) _ 0. 0035 HV _ v 0.0175 and Q _ (max) _ (max) _ 0. 0039 Hv / v 0.06 respectively. (3) the calculation results of heat release rate are analyzed according to the fire source heat release rate t ~ 2 model. The thermal release rate t ~ (2) model of coal and pit wood combustion is obtained. The development coefficient and attenuation coefficient of coal are 12kW/min~2 and 0.12 kW / min ~ (-2), and 12kW/min~2 and 2.2 kW / min ~ (2), respectively. Based on the integral calculation of the heat release rate t ~ 2 model of the fire source, the total heat release equation of the fire source is established. The total heat emission is divided by the mass of the coal as the heat release of the coal per unit mass. The heat release of unit mass coal and pit wood is calculated to be 432kJ and 1658kJ respectively. (4) the experimental coefficient of temperature field equation Kc is determined by experiments, that is, in the development stage of the fire, in the stable stage of the fire, and in the attenuation stage of the fire, the experimental coefficient of the temperature field equation is Kc. The theory of section temperature t _ 2 model is studied, and the model of section 3 temperature variation t _ 2 is established. The development coefficient and attenuation coefficient are 0.251K/min~2 and 0.0708K / min ~ (2), respectively. (5) the analysis of the variation law of wind direction temperature field under fire zone shows that, In the development and stabilization stage of mine roadway fire, the temperature of air flow in the downwind roadway decreases with the increase of the distance from the fire area. At the attenuation stage of the fire, due to the unstable source of the fire and the inflow of fresh wind flow, there is a section of the downwind roadway in which the temperature drops fastest, which begins near the fire zone. Then it gradually moves down to the distance of the roadway. (6) the total resistance of the fire source and the resistance of the fire zone are analyzed. It is concluded that the total resistance of the fire source in the roadway is composed of the positive resistance, the friction resistance and the resistance in the fire zone. The positive resistance decreases gradually with the decrease of the volume of the combustion material, and the friction resistance remains unchanged, and the resistance in the fire zone increases gradually in the development and steady combustion stage, then decreases and tends to zero at the attenuation stage. The maximum value of resistance in fire zone is 71.5 Pa. when the air flow temperature increases to 351.6 K and the air volume of roadway is 0.419m3/s.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TD752
【参考文献】
相关期刊论文 前10条
1 傅培舫;周怀春;;巷道火灾过程中燃烧速率和释热速率的预测[J];燃烧科学与技术;2006年05期
2 程小虎;曾艳华;何川;范磊;;隧道火灾中火区阻力的理论研究[J];铁道学报;2007年05期
3 于丽;王明年;郭春;;秦岭特长公路隧道火灾温度场的数值模拟[J];土木工程学报;2007年06期
4 常相辉;冯先富;张永文;刘斌;;不同温度下空气比热容比测量装置的研究[J];物理实验;2011年04期
5 郭江炜;宋双林;于s
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