Study On The Characteristics Of Powder Explosion Suppressant To Suppress Gas Explosion In Pipe Network

For the increase of low concentration gas extraction in China,long distance pipeline transportation process serious safety hazards,using a combination of theoretical analysis and experimental research methods,to carry out powder explosion suppressants to inhibit the propagation characteristics of gas explosion in the pipeline network research,for the improvement of explosion suppression device and the control of the scope of gas explosion disaster in the pipeline has practical significance.The following main research results were achieved:Through the independent construction of the experimental pipe network system for the experimental study of gas explosion propagation without explosion suppression measures,to get no explosion suppression measures for each pipe shock wave,flame front change law,explosion shock wave overpressure,explosion power index,flame front speed,flame front temperature change characteristics.Experimentally derived shock wave propagation in the pipe network appeared multiple attenuation and superposition,the forward propagation of shock waves and shock waves in all interconnected pipes in the pipe network superimposed on the reverse propagation,resulting in the propagation of shock waves show a complex disorder.Shock wave propagation in different pipe structure,after 45°bifurcation pipe when the explosion power is the largest,397.1×10⁹Pa²/s;in the oblique angle joint branch pipe,the pressure loss is the largest,overpressure explosion power decline is the largest,the fastest flame front propagation speed,382.7m/s;the bottom straight pipe in the slowest flame front propagation speed,343.6m/s.Through the independent construction of the experimental pipe network system for the three powder explosion suppressants（KHCO₃,K₂C₂O₄,KH₂PO₄）and KHCO₃ powder particle size and spray powder pressure suppression of gas explosion experimental research,to obtain the three powder explosion suppressants and KHCO₃ powder particle size and spray powder pressure on the suppression of gas explosion shock wave,flame front suppression performance.Experimentally derived after adding powder suppressant,KHCO₃,K₂C₂O₄,KH₂PO₄ powder suppressant on the explosion overpressure has a better inhibitory effect,overpressure shock wave of multiple superposition and decay process nearly disappeared,the monitoring point overpressure time curve are"single peak"characteristics,the time required to reach the peak overpressure increased significantly.KHCO₃ powder inhibitor working conditions in the explosion overpressure peak drop in 83.2%-89.3%,K₂C₂O₄ powder inhibitor working conditions in the explosion overpressure peak drop in 67.7%-78.3%,KH₂PO₄ powder suppressant working conditions in the explosion overpressure peak drop in the range of 43.0%-57.7%.That is,three kinds of powder explosion suppressants to inhibit the role of overpressure in order of strength:KHCO₃>K₂C₂O₄>KH₂PO₄.Similarly,for weakening the explosion power,reduce the flame front speed,flame front temperature,KHCO₃ performance is the best,K₂C₂O₄ second,KH₂PO₄ the worst.Experimentally derived in the spraying pressure of 0.1-0.2MPa range,increase the KHCO₃spraying pressure on the explosion suppression effect has significantly improved,when the spraying pressure increased to 0.2MPa,the explosion overpressure,explosion power index,flame front speed,flame front temperature to the lowest,continue to increase the spraying pressure on the suppression of explosion no significant effect.The smaller the particle size of KHCO₃ powder,each monitoring point explosion overpressure,explosion power index,flame front speed,flame front temperature peak is lower,the better the effect of gas explosion inhibition,that is,the particle size of 50-75μm of each monitoring point explosion overpressure,explosion power index,flame front speed,flame front temperature peak is the lowest,the best effect of explosion inhibition.The thesis has 33 figures,9 tables,and 89 references.