Study On Characteristics And Suppression Of Hydrogen/Methane/Air Mixture Explosion In Enclosed Space

Focus on the growing energy crisis,the hydrogen energy has been further studied.At present,the hydrogen-enriched compressed natural gas has been used in production practice as a car fuel,but the issue of the safe use has caused wide attention of scholars.Therefore,this paper explored the explosion characteristics of hydrogen/methane/air mixture with different hydrogen contents.In addition,the research on the suppression of hydrogen/methane/air mixture explosion by ultra-fine NH₄H₂PO₄ powder was carried out,and the influence of hydrogen content on the critical triggering time of the suppressor and the minimum powder application amount was explored.To seeking the best explosion suppression effect of powder medium,different powders were studied.The main contents and conclusions are following:（1）For simulating transportation,storage and other application scenarios,a visualized medium horizontal confined explosion experimental device was designed.The hydrogen/methane/air mixture explosion and suppression experimental platform consists of the gas distribution system,ignition system,data acquisition and control system,explosion suppression medium injection system and explosion experimental device.（2）The study on the explosion of hydrogen/methane/air mixtures with different hydrogen contents was carried out,which found that the rate of pressure rose and peak value gradually increased with the increase of the hydrogen content of the mixtures,while the initial rise time of the explosion pressure was gradually delayed.Meanwhile,the explosion flame propagated expeditiously,which regular structure was broken and the color changed from orange to light blue.（3）Experiments were carried out on the suppression of hydrogen/methane/air mixture explosion by ultrafine NH₄H₂PO₄ powder.The results show that with the decrease of the triggering time of the suppressor and the increase of the amount of powder applied,the explosion suppression effect of the powder medium gradually enhanced.（4）The influence of hydrogen content on the critical trigger time and the minimum amount of powder applied to the detonator suppressor was investigated.It was found that the critical trigger time of the detonator suppressor for the mixture containing 0%,25%and 50%hydrogen was effectively inhibited by 40g ultra-fine ABC powder,which was 50ms,40ms and 25ms,respectively.When the trigger time of explosion suppressor is 50ms,the minimum powder dosage for effective explosion suppression is 40g,60g and 80g,respectively.（5）The explosion suppression effect of KHCO₃,NaHCO₃ and SiO₂ powders was further studied,and the effects of the three powders in inhibiting the explosion of hydrogen/methane/air mixture containing 25%hydrogen were determined to be:KHCO₃>NaHCO₃>SiO₂.