密闭储罐内填充非金属多孔材料后预混可燃气体火焰传播的数值模拟

Simulation for the propagation of the premixed combustible gas flame in a closed tank with non-metal porous materials

采用商业软件Fluent 6.3建立了二维的多孔介质中湍流燃烧模型,对密闭储罐内多孔介质中丙烷-空气预混燃烧进行数值模拟。结果表明:火焰在空爆时比在填充多孔材料后发展的快得多,空爆时表压数量级为106,而填充多孔材料后表压数量级为104,说明此非金属多孔材料有很好的阻火性能和抑爆性能;且多孔材料的平均孔径越小,其阻火防爆性能越好。

The present paper is aimed to explore the propagation regularity of the flame of the premixed combustible gas in a closed tank filled with non-metal materials in the form of transient pressure wave.For the given research purpose, we have developed a two-dimensional turbulent combustion model in the porous media via a computational fluid dynamics （CFD） and a commercial software named Fluent 6.3. Along with the above said simulation method, we have also made the simulation with the CFD software and taken the turbulent effect and the radiation heat transfer of the porous media solid matrix into full account. The simulation results indicate that the flame develops faster without the packing porous materials than with them. To be exact, it has been found that the pressure in the tanks would reach 106 Pa with no porous media whereas the maximum pressure rose only to 104 Pa on the condition when the porous media was packed. Therefore, it can be concluded that the porous media turn to have excellent performance in suppressing the fire and explosion tendency. The smaller the average size of porous media, the more advantageous the perfor- mance of the fire and explosion suppression in accordance with the comparison results among different pore sizes of the porous media, though the performance of the fire and explosion suppression tend to get better, if the aperture of the porous media is continually going to reduce. The simulation results prove to be a bit higher in contrast with the experiment results. For example, the maximum pressure ex- periment result is 63 kPa when the average aperture is 8mm, howev- er, the simulation result proves to be 78 kPa with an error of 19.2% , though the pressure trends seem to be consistent with the average errors remaining in the allowed range. Therefore, it can be concluded that the numerical simulation method we have developed by using FLUENT software can truly and trustfully reflect the transient explosion pressure wave and the flame propagation process, thus, demonstrating the positive significance for the development of the experiment scheme.