Study On Explosion Characteristics Of Methane Gas And Gas-liquid Two-phase Explosion Suppression

The CH₄explosion accident is a problem that has plagued our country’s security departments and governments at all levels for a long time.The casualties caused by the recent gas explosion accident in Shiyan,Hubei,my country once again sounded the alarm for us.In order to reduce the consequences of CH₄explosions,the state has invested a lot of manpower,material resources and financial resources to build a complete safety management system and increase the investment of researchers in related research to avoid the occurrence of CH₄explosion accidents.In this paper,a 20 L spherical explosive device is used to study the explosion characteristics of CH₄and the CH₄suppression rule under the synergistic effect of inert gas,water mist,and inert gas-water mist.The research results are as follows:（1）The explosion characteristics of CH₄mixed gas with different concentrations in the air are experimentally studied.The results show that under the experimental conditions,the upper and lower explosion limits of CH₄are tested,which are 5%and 15%respectively,which are basically consistent with the conclusions in the literature.With the increase of CH₄concentration,the maximum explosion pressure of CH₄mixed gas and the rising rate of maximum explosion pressure showed a trend of first increasing and then decreasing.When the CH₄concentration reached 15%,the CH₄mixed gas would not explode.（2）Use inert gases CO₂,N₂and Ar to conduct explosion suppression test research on CH₄mixed gas.The results show that the three inert gases have certain inhibitory effects on the explosion pressure of CH₄mixed gas.With the increase of the inert gas concentration in the mixed gas,the maximum explosion pressure and the rising rate of the maximum explosion pressure of the CH₄mixed gas both decreased significantly.In CH₄mixed gas,when the CO₂concentration reaches 6%,the maximum explosion pressure drops to 0.113 MPa,and the maximum explosion pressure rise rate drops to 1.58 MPa·S^-1;when the N₂concentration reaches 6%,the maximum explosion pressure drops to 0.275 MPa,the increase rate of the maximum explosion pressure decreased to 4.10 MPa·S^-1;when the Ar concentration reached6%,the maximum explosion pressure decreased to 0.284 MPa,and the increase rate of the maximum explosion pressure decreased to 4.20 MPa·S^-1.It can be seen that the explosion suppression effect of the three inert gases on the CH₄mixed gas is CO₂>N₂>Ar under the same concentration.The explosion suppression effect of CO₂is better than that of the other two inert gases.（3）The effect of water mist on the active explosion suppression of CH₄mixed gas was studied.The results show that:when the atomization pressure is constant,the explosion suppression effect of the water mist sprayed by the 2.4 mm aperture nozzle is the best;when the nozzle aperture is constant,with the increase of the atomization pressure of the water mist,the explosion suppression effect of the water mist is enhanced.（4）A nozzle of 1.5 mm aperture with relatively stable experimental data was selected to study the effect of water mist-inert gas on the explosion suppression of CH₄mixed gas.The results show that among the inert gas-water mist synergistic explosion suppression,CO₂-water mist has the best synergistic explosion suppression effect,followed by N₂-water mist,and Ar-water mist has the worst synergistic explosion suppression effect.