矿井胶带火灾烟气流动模拟及危险区域划分

发布时间：2018-03-18 15:52

本文选题：平直巷道　切入点：胶带火灾　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：胶带火灾是煤矿井下常见的一种外因火灾,胶带巷中可燃物多,一旦发生胶带燃烧,火势会迅速发展,形成典型的巷道火灾。矿井胶带火灾产生的烟气随风流蔓延,在狭长的巷道空间中形成一种高温毒害的环境,危害井下矿工的健康甚至生命。因此,研究矿井胶带火灾烟气蔓延规律以及蔓延危险区域范围是很有必要的。本文通过分析胶带火灾发展过程中烟气温度场和烟气浓度场的变化规律,对巷道空间进行危险区域划分。主要内容和结论:通过归纳和总结,分析胶带燃烧特性和胶带火灾发生的原因,根据受限空间火灾的发展过程,将胶带火灾发展过程分为初起阶段、发展阶段、猛烈阶段、衰减和熄灭阶段。并将初起阶段和发展阶段作为研究的重点。在5种风速条件下,用平直巷道火灾实验平台进行胶带燃烧实验,发现:巷道通风速率为0.4m/s时,胶带燃烧的质量损失速率最大。在胶带燃烧速率最佳的实验风速条件下,模拟胶带火灾初起阶段烟气蔓延情况,研究胶带火灾初起阶段巷道中温度场以及CO和CO_2气体浓度随时间和空间位置的变化规律。同时,基于Fluent数值模拟软件,以平直巷道胶带燃烧实验为原型,设计胶带火灾发展阶段的火灾模型,模拟胶带火灾发展阶段巷道中的烟气流动,掌握了胶带火灾发展阶段巷道中温度场和气体浓度场随时间和空间位置的变化规律。以巷道中高温有毒烟气为评价对象,建立了烟气高温和毒害评价指标,对胶带火灾初起阶段和发展阶段烟气蔓延区域进行危险性划分。综合毒害和高温区域的划分结果发现:在初起阶段,巷道整体为安全区域,火源附近为亚安全区域;在发展阶段,巷道空间分为安全区域、亚安全区域、中度危险区域和危险区域,且各区域的范围随着火灾发展时间不断的变化,此外,相比于高温划分的非安全区域,毒害划分的非安全区域范围更大、危险程度更高,其安全区域范围的缩小速率为0.13～0.38m/s,危险区域范围增大速率为 0.04～0.32m/s。
[Abstract]:Belt fire is a common external fire in coal mine. Once the belt burning occurs, the fire will develop rapidly and form a typical tunnel fire. The smoke produced by the belt fire spreads with the air flow. In the long and narrow tunnel space, a high temperature toxic environment is formed, which endangers the health and even the life of the underground miners. It is necessary to study the spread law of smoke and the range of dangerous area in mine belt fire. This paper analyzes the variation law of flue gas temperature field and smoke concentration field during the development of belt fire. The main contents and conclusions are as follows: through induction and summary, the characteristics of belt burning and the causes of belt fire are analyzed, and according to the development process of restricted space fire, The development process of belt fire is divided into initial stage, development stage, violent stage, attenuation stage and extinction stage. Using the flat roadway fire experiment platform, it is found that when the ventilation rate of roadway is 0.4 m / s, the mass loss rate of belt burning is the greatest. In order to simulate the flue gas spread in the initial stage of belt fire, the temperature field and the variation law of CO and CO_2 gas concentration with time and space were studied. At the same time, the numerical simulation software Fluent was used to simulate the temperature field and the concentration of CO and CO_2 gas in the roadway during the initial stage of belt fire. Based on the belt burning experiment of straight roadway, the fire model of belt fire development stage is designed, and the smoke flow in roadway is simulated in the development stage of belt fire. The variation law of temperature field and gas concentration field with time and space in roadway during the developing stage of belt fire were mastered. The evaluation index of high temperature and poison of flue gas in roadway was established by taking high temperature toxic flue gas in roadway as the evaluation object. In the first stage of belt fire, the risk of smoke spread is divided between the initial stage and the developing stage. The results of the comprehensive division of toxic and high temperature areas show that, in the initial stage, the roadway as a whole is a safe area, and the fire source is a sub-safe area near the source of fire; In the development stage, the roadway space is divided into the safe area, the sub-safe area, the moderate dangerous area and the dangerous area, and the range of each area changes with the fire development time, in addition, compared with the non-safe area of high temperature, The range of non-safety area divided by poison is larger and the degree of danger is higher. The reduction rate of safety zone is 0.13m / s, and the increase rate of dangerous area is 0.04n0.32m/ s.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD752

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