不同迎爆面结构的泡沫金属对甲烷气体爆炸传播阻隔性能的实验研究

Experimental study on barrier performances of foamed metals with different blast front structures to prevent methane explosion propagation

通过自行设计的爆炸管网设备进行实验,提出通过改变泡沫金属迎爆面的结构来增大与爆炸火焰的接触面积,结合爆炸超压、火焰传播速度和火焰温度等参数来评价不同迎爆面设计结构的泡沫金属的阻隔爆性能。结果表明,在相同厚度的前提下,在材料迎爆面增加一定的锯齿形波纹会使整体的阻隔爆性能有所提升,爆炸超压、火焰传播速度和火焰温度的衰减率随着迎爆面锯齿角度的减小而增大。当泡沫金属迎爆面锯齿角度为30°时,爆炸超压、火焰传播速度和火焰温度的衰减率分别为74.0%、76.18%和91.93%,爆炸超压下降速率为30.76 MPa/s,材料后端熄爆参数为17.68 MPa·℃,阻隔爆效果较好。

The shock waves and flame produced by explosions of methane(CH4) and other combustible gas explosion can cause huge casualties and property damage. Therefore, the explosion-proof isolating technologies have always been a hotspot in the fields of industrial explosion protection. Foamed metal has attracted attention as a new type of explosion-isolating material which can simultaneously block the propagation of gas explosion shock waves and flame waves. Its explosionisolating performance is a key factor affecting its application. However, there are few researches on improving the explosionisolating performances of materials by changing the overall structures of foamed metals. A new method was proposed to change the structure of the blast front of a foamed metal and increase the contact area of the blast front with the explosion flame, so as to improve the flame-proof performance of the foamed metal. In this experiment, the experimental material with the thickness of 20 mm was prepared by wire cutting. Under the premise of the foundation thickness of 15 mm, the explosive effect surface was prepared into serrated ripples with the thickness of 5 mm and the angles of 30°, 60° and 90°. The processed foamed metal materials with different explosive effect surfaces were installed in the diffusion pipe near the end of the experimental equipment. The sensors placed at different positions and with different distances were used to collect the relevant data, and thereby the attenuation ratios of explosion overpressure, flame propagation velocity and flame temperature were calculated. The explosion-proof performances of the foamed metal with different saw tooth angles were evaluated by combining the explosion-extinguishing parameters. The results show that under the premise of the same thickness, the increase of a certain zigzag wave on the explosive effect surface of the material will improve the overall isolating explosion performance. The attenuation ratios of explosion overpressure, flame velocity, and flame temperature increase with the decrease of the sawtooth angle. When the front surface of the foamed metal has a sawtooth of 30°, the attenuation ratios of explosion overpressure, flame velocity, and flame temperature are 74.0%, 76.18%, and 91.93%, respectively. The explosion overpressure decay rate is 30.76 MPa/s, and the explosion is extinguished at the rear end of the material. The quenching parameter at the rear-end of the material is 17.68 MPa·℃, and the isolating explosion effect is better.