Abstract: The deflagration experiments were carried out in the 2000m³ experimental base to study the increase mechanism of overpressure wave induced by a semispherical porous barrier. In the center of semispherical acetylene-air clouds with a mixture ratio 7.8% was an ignition electrode that met ISO 6184 “Explosion Protection System" and NFP A68 “Guide For Venting of Deflagrations". The built-in semispherical porous barriers were concentric with the clouds. A data-acquisition system, with dynamic responding time less than 1ms recorded the explosion pressure-time diagrams of deflagrations. It was clear from the simultaneous records of the deflagration process that the flame propagated in sphere initially and became bent and folded at barriers. Meanwhile the burning rate increased. The experimental results showed that the deflagration overpressure increased with the increase of barrier radius and the number of barriers. The deflagration overpressure also increased with the reduction of interspaced ratio.

Key words:

可燃气云, 爆燃, 爆炸

摘要： 在体积为2000m³的实验基地，进行了半球面筛孔形障碍物对半球形气云爆燃压力的增长机制影响的实验研究。可燃介质是浓度为7.8%的半球形乙炔-空气混合气云，气云内置半球面筛孔形障碍物，爆燃压力由精度为0.5级、动态响应时间小于1ms的压力变送器感受，点火装置为符合国际标准ISO6184 “Explosion Protection System" 和美国标准NFPA68Guide For Venting of Deflagrations"的电火花点火。火焰传播过程的图像记录显示，爆燃火焰在遇到障碍物之前基本上以球面向外扩展，经过障碍物后会发生显著扭曲和折叠，燃烧速率增大。压力场测试结果表明，障碍物孔隙率越小、半径越大、层数越多，爆燃压力就越高。

关键词:

可燃气云, 爆燃, 爆炸