大型相连容器中火焰传播的研究

Study on Flame Propagation in Large-scale Interconnected Vessels

为了进一步了解相连装置中粉尘爆炸的火焰传播行为和压力发展,为该结构的安全防护设计提供有价值的信息,采用大型实验装置对相连容器中玉米淀粉/空气混合物爆炸时的火焰传播行为进行了实验研究,同时采用已开发的数值模型对实验进行仿真计算。实验表明:粉尘浓度的变化对粉尘爆炸的火焰传播行为有重要影响;在粉尘浓度很低的情况下,火焰仍然能够在管道中加速传播且爆炸发展的最终结果相当猛烈。数值模型采用欧拉-拉格朗日方法模拟两相流现象,通过求解非稳态的湍流两相反应流守恒方程对实验进行二维仿真,计算结果与实验结果符合性较好,表明该模型可以很好地应用于粉尘爆炸火焰传播的研究。

In order to get more information concerning flame propagation and pressure in pipes of interconnected vessels and thereby to provide valuable information for safety protection and design, the flame propagation through pipes in large interconnected vessels produced by maize starch dust explosion was in- vestigated by experimental and numerical approaches. The experimental result shows that dust concentration has an important influence on the flame propagation behavior; under a very low dust concentration, the flame can still propagate in pipes with acceleration and produce a very violent explosion eventually. In simulation, the Eulerian-Lagrangian approach was used as a numerical model to simulate the phenomenon of two-phase flows, and a two-dimensional simulation on the above experiment was conducted by solving the conservation equations of unsteady turbulent two-phase reacting flows. The simulation results are in good accord with the experimental ones, which demonstrates that the numerical model can be well applied in the study of flame propagation caused by dust explosion.