矿井巷道火灾烟流数值模拟及安全区域划分

发布时间：2018-05-06 02:43

本文选题：矿井巷道火灾 + 烟气流动　；参考：《江西理工大学》2015年硕士论文

【摘要】：火灾因其危害性大成为矿山主要灾害之一。火灾产生的高温有毒有害烟气在井下狭长受限空间内流动,不仅损坏井下设备和影响正常生产,而且污染井下作业环境,威胁作业人员生命健康。因此,对矿井火灾烟气流动的研究具有重要意义。本文主要研究内容是对矿井巷道火灾烟气流动进行数值模拟分析,并在此基础上对井下巷道进行安全区域划分。首先,建立矿井巷道火灾风流流动连续性方程、动量方程、能量方程、组分方程。其次,对外因火灾和内因火灾形成原因进行了具体系统地分析。再次,通过GAMBIT软件建立相似物理模型后导入FLUENT软件进行井下巷道火灾烟气流动数值模拟,分别对巷内发生火灾后机械通风和巷道风流稳定时发生火灾,这两种情况进行数值模拟。并选取了巷内风速、火灾规模两个影响因素分组进行模拟。最后,对火灾灾变时期巷道内安全区域进行划分,并列举了根据温度和CO浓度对巷道安全等级区域划分的实例。研究结果表明:巷道内发生火灾后机械通风和巷道风流稳定时发生火灾两种情况,经过较长时间后,当火灾产生烟气与排出烟气量达到一定平衡后,巷道内烟气流动均趋于稳定流态;当巷道内风速较小或火灾规模较大时,火灾产生的高温有毒有害烟冲向顶板形成“蘑菇状”,部分烟气会沿巷道顶板向火源上游流动,对火源上游巷道有一定污染,并且对火源下游巷道污染严重;随着巷道内风流的增大,排出烟气的速率有所增大,逐步消除烟气对火源上游巷道的污染,烟气浓度有所降低,巷道气流的温度也随之降低,排烟的效果更好;随着火灾规模的增大,巷道内烟气浓度和温度增大,对火源下游巷道的污染加强,同等风速排出烟流的能力明显降低,排烟效果随之减弱。本文通过对矿井巷道火灾烟气流动进行数值模拟,揭示了巷道内火灾烟气流动和温度、有毒烟气分布规律,供矿山巷道火灾防治作参考。此外,根据模拟结果和不同温度值、有毒气体浓度对人体影响,对矿井巷道安全区域等级进行划分,对井巷火灾抢险救灾和人员紧急逃生具有一定的参考价值。
[Abstract]:Fire has become one of the main disasters in mines because of its great harmfulness. The high temperature, toxic and harmful smoke produced by fire flows in the narrow and narrow confined space, which not only damages the underground equipment and affects normal production, but also pollutes the working environment and threatens the life and health of the workers. Therefore, the study of mine fire smoke flow is of great significance. The main research content of this paper is to simulate and analyze the smoke flow of mine roadway fire, and on this basis, to divide the safe area of underground roadway. Firstly, the continuity equation, momentum equation, energy equation and component equation are established. Secondly, the causes of external fire and internal fire are analyzed systematically. Thirdly, building similar physical model by GAMBIT software and introducing FLUENT software to numerical simulation of smoke flow in underground roadway fire, respectively, when mechanical ventilation occurred in roadway fire and roadway wind flow stabilized, fire occurred respectively. These two cases are numerically simulated. Two factors, wind speed and fire scale, are selected for simulation. Finally, the safe area in the roadway during the period of fire disaster is divided, and an example of dividing the safety zone of the roadway according to the temperature and CO concentration is given. The results show that there are two kinds of fire conditions: mechanical ventilation after fire in roadway and steady air flow in roadway. After a long time, when the smoke produced by the fire reaches a certain balance with the amount of flue gas discharged, The flue gas flow in roadway tends to steady, when the wind speed is small or the fire scale is large, the high temperature, toxic and harmful smoke produced by the fire will rush to the roof and form a "mushroom" shape, and some of the smoke will flow along the roof of the roadway to the upstream of the fire source. With the increase of the air flow in the roadway, the rate of flue gas emission increases, gradually eliminating the smoke pollution of the upstream roadway of the fire source, and the smoke concentration decreases, while the upstream roadway of the fire source is polluted, and the downstream roadway of the fire source is polluted seriously. With the increase of fire scale, the concentration and temperature of flue gas in the roadway increased, the pollution of the roadway downstream of the fire source was strengthened, and the ability of the same wind speed to discharge smoke flow was obviously reduced. The effect of exhaust smoke was weakened. Through numerical simulation of fire smoke flow in mine roadway, this paper reveals the distribution law of fire smoke flow, temperature and toxic smoke in roadway, which can be used as a reference for mine roadway fire prevention and control. In addition, according to the results of simulation and different temperature values, the influence of toxic gas concentration on human body, the classification of mine roadway safety area grade has certain reference value for mine roadway fire rescue and rescue and personnel emergency escape.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD752

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