Experimental Study Of Inhibition Characteristic Of Foam Copper On Methane Explosion

Gas is a high-quality clean energy.However,during the process of gas extraction and transportation,it is easy to explode,which may result in property damage and heavy casualties.Therefore,it is of great significance to study how to effectively suppress the gas explosion of gas drainage pipeline.There are currently two problems in the research of gas explosion suppression.First,the initiation point is random,that is,the explosion may occur at any position of the pipeline.The influence of the position of the foam on the gas explosion when the position of the foam material is different from the location of the initiation point;Second,the differences in the power of gas explosion may cause differences in the effect of explosion suppression.Thus,this paper has carried out experimental research on the above two issues.Experimental study on the inhibition characteristics of 35PPI foam copper at different positions from the ignition end for methane explosion,that is,35PPI foam copper is placed at 400mm,900mm and 1200mm from the ignition end to study its effect on methane explosion suppression.The research results are as follows:When the initial pressure of the premixed gas inside the pipeline are 6,7,8kPa respectively,35PPI foam copper can completely quench the explosion flame,and it has a good inhibitory effect on the flame speed and the explosion overpressure;When the initial pressure of the premixed gas inside the pipeline is 9kPa and 35PPI foam copper is placed at 400mm and 900mm from the ignition end,the explosion flame can be completely quenched,and the overpressure value after the foam copper is unchanged.When foam copper is at 1200mm from the ignition end,the flame cannot be quenched and passes through the foam copper,and the overpressure after the foam copper increases;When the initial pressure of the premixed gas inside the pipeline is10kPa,35PPI foam copper cannot quench the explosion flame,and has an excitation effect on the explosion flame velocity,and the overpressure after the foam copper increases;However,compared with the explosion overpressure in the case of the empty pipe,the explosion overpressure after the addition of foam copper is reduced due to the energy absorption effect of foam copper.Experimental study on the inhibitory effect of foam copper on different methane explosion states,that is,the suppression effect of different thickness 70PPI foam copper on methane explosion of different energy levels when foam copper is at900mm from the ignition end.The research results are as follows:In the deflagration state of the CH₄/O₂ premixed gas,the explosion can be inhibited when adding 10mm thick 70PPI foam copper at 900mm.There is no significant change in overpressure after foam copper;In the DDT stage,only 30mm thick foam copper can completely inhibit explosion,block the explosion flame propagation,and the overpressure after the foam copper does not change.However,20mm and 30mm thick foam copper have attenuated explosion flame velocity.20mm thick foam copper has a stronger inhibition effect than the 10mm thick foam copper,but as explosion flame velocity increases,the gap gradually narrows;In the detonation state,only 10mm thick foam copper can not quench the explosion flame,but 10mm thick foam copper has attenuated flame speed.When the initial pressures are 14kPa and 16kPa respectively,explosion flame velocity will decay from detonation phase to deflagration phase;The resistance loss before and after the gas passes through the copper foam is complicated with the gas flow velocity,and the gas flow resistance increases as the gas flow rate increases.As the initial pressure of the premixed gas increases,the temperature and velocity of the explosion gas increase,and the dynamic viscosity and flow resistance increase rapidly.When the resistance caused by the pores is large enough,the flame will be quenched.