Experimental Study On Gas Explosion Suppression By Inert Gases-additive And Water Mist

Water mist suppression technology has been widely researched and applied in the field of ground fire protection because of its advantages of high efficiency,cleanliness and low cost.However,the research on mine disaster prevention is relatively few.Based on the water mist suppression technology,put forward a kind of inert gas additive water mist suppression technology,based on the original water mist,while adding additives and inert gas,studying on the suppression effect of using the technology by means of methods of numerical simulation and experimental.The results of the research are as follows:（1）The influence of CO₂ dual flow water mist and N₂ double flow water mist on the overpressure and explosion temperature of gas explosion is studied by CHEMKIN-PRO software.The mechanism of inhibiting gas explosion is obtained from the influence of H,O and OH free radicals.The data shows that the explosion suppression effect of CO₂dual flow water mist and N₂ double flow water mist is better than that of water mist alone,and the effect of CO₂ dual flow water mist is better than N₂ dual flow water mist.It proves the synergistic inhibition effect of inert gas and water mist on gas explosion.（2）By use of the Beijing Institute of Technology explosion experiment system,combined with the self-designed twin fluid water mist generating device and a twin fluid nozzle,building gas explosion experiment system,including the system of pipeline system,water mist generating system,data acquisition system,high-speed photography system and ignition system,this system can realize the flame signal,pressure signal acquisition and image the shooting of gas explosion.（3）Collectioning each flame sensor signal and arrival time by use of flame sensor reached along the pipeline layout,calculating gas explosion flame propagation speed of the 7 kinds of conditions,the research shows that the propagation velocity of 9.5%CH₄ explosion in long pipeline is 71.43m/s,in the addition of different inhibitors,under the condition of water mist zone the propagation velocity was decreased in different degree,case 6 shows largest decline,when the flame through the mist flame zone,instead of explosion suppression,but the promotion of gas explosion.（4）Collectioning the flame image using a high-speed camera explosion under the 7 conditions,and using the MATLAB software conduct image collected,analyzed and calculated using the average flame boundary method,the curve of flame propagation velocity with time was obtained under the 7 conditions,the method of average flame boundary is more accurate than the method with flame sensor calculated.（5）Collecting the gas explosion overpressure data under 7conditions by use of pressure sensor,comparative analysis of influence of overpressure in the 7 conditions,gas explosion overpressure along the pipelineof is studied under different conditions,the inert gas,additive and water mist has a synergistic inhibitory effect on suppressing gas explosion and the inhibitory effect of the gas explosion under the conditionoftheorderis（superior→inferior）:0.5CO₂-6%KCl-0.5H₂O-9.5%CH₄>0.5N₂-6%KCl-0.5H₂O-9.5%CH₄>0.5CO₂-0.5H2O-9.5%CH₄>0.5N₂-0.5H₂O-9.5%CH₄>0.5air-6%KCl-0.5H₂O-5%CH₄>0.5air-0.5H₂O-9.5%CH₄.（6）Design orthogonal experiment,Orthogonal analysis of experimental results,At the same time,the variance analysis table is used to analyze the main and secondary order of CO2,KCl,and fine water mist on gas explosion suppression.It is concluded that the primary and secondary order of the three anti explosion is（main to secondary）CO₂>fine water mist>KCl,The optimal ratio is A₃B₂C_3.The intermediate value of the optimal effect of KCl explosion suppression is obtained by fitting the parabolic data,the experimental results provide clues for further research.