多孔材料下气体爆炸转扩散燃烧的特性研究

为分析多孔材料对预混气体爆炸特性参数的影响效果，采用自主搭建的爆炸实验平台，探究不同孔隙度和厚度的多孔材料对当量比为1的甲烷/空气预混气体爆炸的作用行为。实验研究表明，不同孔隙度的多孔材料对爆炸火焰和超压具有促进或抑制两种不同的影响。孔隙度较小时，爆燃火焰传播速度随着材料厚度的增大而降低，并在厚度较大时，火焰有短暂的传播延时现象。孔隙度较大时，预混火焰冲击多孔材料时发生淬熄，但随后一段时间内，由于负压抽吸作用，在已爆区域一侧的材料表面产生扩散燃烧现象，且扩散燃烧程度与材料厚度成反比关系。多孔材料的固相结构能降低压力的泄放效率，同时可吸收能量，进而提高爆炸超压的上升速率，降低超压峰值。当每英寸长度孔数δ=10的多孔材料促进火焰传播时，与当量比为1的预混气体爆炸相比，超压峰值最大可提高约2倍，造成更严重的后果。火焰冲击δ=20的多孔材料时发生淬熄，最大超压衰减可达47.17%，δ=30时最大超压衰减了24.62%。

Characteristics of gas explosion to diffusion combustion under porous materials

To analyze the effect of porous materials on the explosion characteristics of premixed gas, a self-built explosion experiment platform was used to investigate the behavior of porous materials with different porosities and thicknesses on premixed methane/air gas explosion with a stoichiometric ratio of 1. Experimental studies have shown that porous materials with different porosities can either promote or suppress the explosive flame and overpressure. When the porosity was low, the propagation speed of the deflagration flame decreased with the increase of material thickness, and when the thickness was large, the flame had a short propagation delay. When the porosity was high, the quenching effect occurred when the premixed flame impacted the porous material. However, in the following period, due to negative pressure suction, diffusion combustion occurred on the surface of the material towards the side of the exploded area, and the degree of diffusion combustion was inversely proportional to the thickness of the material. The solid phase structure of porous materials could reduce the efficiency of pressure release and absorb energy, resulting in increasing the rate of explosion overpressure rise and reducing the overpressure peak. When the porous material with δ=10 were used to promote flame propagation, compared with premixed gas explosions with a stoichiometric ratio of 1, the peak overpressure could be increased by about 2 times at most, causing more serious consequences. Quenching occurred when flame impacted the porous material with δ=20, and the maximum overpressure attenuation was 47.17%. The maximum overpressure decreased by 24.62% at the porous material with δ=30.