【作者】 杨书召；

【导师】 景国勋；

【作者基本信息】 河南理工大学 ， 安全技术及工程， 2010， 博士

【摘要】 本文基于气体和粉尘爆炸理论,采用实验测试、理论分析、数值模拟三种方法,系统地研究了受限空间煤尘爆炸传播规律及事故伤害特性。研究成果为煤尘爆炸事故危险性分析以及救援决策提供理论和技术支持。利用自行设计的爆炸实验系统,进行了管道和巷道内煤尘爆炸传播特性的物理对比实验。实验结果表明,煤尘爆炸冲击波超压的变化呈现先增加后衰减的整体趋势,大尺寸巷道较小尺寸巷道衰减较慢;巷道内的火焰传播距离是原煤尘集聚区长度的2倍左右,火焰在管道内的传播距离远大于巷道内的传播距离,两者并不遵循一般流体力学的相似率,存在尺度效应,通过实验数据得到管道内爆炸火焰传播距离随爆炸煤尘量变化的指数关系;爆炸冲击波过后冲击气流以一定的速度沿冲击波前进方向流动;爆炸毒害气体的传播是分阶段进行的。即,第一阶段是在火焰作用下高浓度毒害气体混合物在爆炸冲击动压的作用下快速膨胀,火焰传播距离与毒害气体传播距离基本相等,存在一个极限传播距离;当毒害气流团膨胀停滞后,则进入紊流扩散传播的第二阶段。不同煤尘量爆炸与毒害气体传播距离的实验数据拟合得到,二者服从指数变化关系。基于煤尘爆炸传播理论和超压伤害准则,建立了爆炸冲击波、火焰、冲击气流和毒害气体传播的事故伤害模型。实验值和理论值对照结果表明,冲击波传播的超压与煤尘爆炸能量成正比,与传播距离和巷道断面积的平方根成反比;火焰传播的火球热辐射伤害动态较静态模型能更准确地评估火球热辐射的后果;爆炸毒害气体沿巷道传播呈指数变化规律。所建立的伤害模型,能够较精确解算出伤害波及的范围和区域,确定伤害的死亡区、重伤区和轻伤区(“三区”)。理论分析还确立了煤尘在弱爆炸和强爆炸两种不同状态下爆炸冲击波随传播距离衰减的计算方法,应用此方法可以推算不同类型爆炸的伤害范围。以连续相、燃烧、颗粒相数理方程建立的煤尘爆炸传播数学模型,能较准确地模拟煤尘爆燃转捩爆轰以及爆炸冲击波、火焰和毒害气体传播衰减过程。煤尘爆炸数值模拟仿真了煤尘爆炸中沉积煤尘颗粒扬起、加速和减速的发展过程和爆炸毒害气体在一定风速下传播扩散的过程,数值模拟结果表明,实验及理论分析得出的爆炸毒害气体浓度随爆炸传播距离成指数规律衰减变化的结论与模拟结果吻合。更多还原

【Abstract】 Based on gaseous and coal dust explosion theory, propagation law of coal dust explosion in confined space and law of accident injure are investigated systematically though the experimental testing, theoretical analysis and numerical simulation. This thesis provides important theoretical and technological supports for the coal dust explosion emergency decisions, accident investigation and analysis results from the coal dust explosion.Physical contrast experiments at the propagation characteristics of coal dust explosion in the pipeline and tunnel are made using self-designed piping explosion system. Research indicates that the overall trend of coal dust explosion blast wave is increases first and then attenuation, and large-size roadway tunnel decays more slowly than the small-size. Besides, the flame propagation distance in roadway is about twice as much as the raw coal dust concentration zone, and flame transmission distance in the pipe is much larger than the distance of the propagation distance inside the roadway which has size effect, and both do not follow the similitude of the general fluid mechanics. What’s more, from the experimental data we obtained that the propagation distance is exponentially related to the variation of coal dust volume. After the blast wave, the blast air (explosion wind) flows along in the direction of the blast wave at a certain speed. The propagation of toxic gas generated by explosion is carried out in stages, that is, the first stage is that the mixture of high concentrations of toxic gas expanded rapidly under the action of the dynamic pressure. The propagation distance of flame and toxic gas are almost equal, and there may be a limit distance in the first phase. When the expansion of toxic gas group stagnate, then enter the second phase of the spread of turbulent diffusion. The result that the propagation distance is exponentially related to the variation of coal dust volume, is obtained by fitting of the experimental data.According to coal dust explosion propagation theory and the overpressure injury 0criterion, set up the accident damage model of explosion blast wave, flame, impact air-flow and toxic gas. After comparing experimental value with theoretical value of the model, we find that the size of blast wave overpressure is proportional to the amount of coal dust explosion, but is inversely proportional to the square root of transmission distance and the sectional area of roadway. Compared with the static model, the dynamic model about the fireball thermal radiation damage of flame spread can be more rational assessment of the consequences of fireball thermal radiation. Furthermore, this damage model is able to calculate the exact solution about injury affected range or area, and ascertain the dead area, deep wounds area and slight injury area (“three areas”). The calculation method of attenuation of blast wave propagation distance under two different states of the coal dust explosion in the weak and strong explosion is also established through theoretical analysis, and this method can calculate the injurie range of different types of blast.The mathematical model of coal dust explosion propagation established according to the continuous phase, combustion, particles of mathematical equations, which can effectively simulate the transtion of explosive burning to explosive detonation. Numerical simulation of coal dust explosion can emulate the development process of coal dust particles scatter, acceleration and deceleration in coal dust explosion and the diffusion process of toxic gas in a certain wind speed. Numerical simulation results show that the conclusion that the decay law of toxic gas concentration is exponentially related to the propagation distance, derived from experimental and theoretical analysis, which conforms to the simulation results.Typical accident of coal dust explosion induced by gas explosion of coal-mine is analysed through appling the accident damage model of explosion blast wave, flame, impact air-flow and toxic gas which established through experiments, theoretical analysis and numerical simulation. Test results indicate that model data is in basic agreements with the actual data measured from the accident, and this model is also featured with a certain reliability, can be applied in hazard analysis of explosion accident.更多还原