Experimental Study On Suppression Of Gas Explosion Propagation By Cavity Structure

The development of the society is closely related to the coal resources.Gas explosion accidents often occur in the process of coal mining.Gas explosion accidents greatly threaten the safety production of coal mines and the lives and properties of the people.According to statistics,more than 50% of the coal mines in China are high-gas mines.Therefore,it is particularly important to carry out research on the suppression of gas explosion propagation.The purpose of this paper is to study the suppression of gas explosion propagation by cavity structure from theoretical analysis and experimental research.In this paper,the chain reaction mechanism of gas explosion is expounded on the basis of predecessors,and the mechanism of explosion suppression of cavity is analyzed.Guided by the results of theoretical analysis,a large-scale gas explosion experiment system was established.The pipe diameter of the experimental system is 200 mm,and the total length of the pipeline is 36 m.The experimental system consists of four parts: explosion pipe network subsystem,distribution ventilation subsystem,ignition subsystem and data acquisition subsystem.The suppression experiments of gas explosions of four different sizes of single cavity structures with a length-diameter ratio of 1.5 and a width-diameter ratio of 1.5 and 2.5 and a length-diameter ratio of 2.5 and a width-diameter of 1.5 and 2.5 were respectively carried out.The results showed that the cavity with a length-diameter ratio of 2.5(500mm*500mm*200mm)had the best explosion suppression effect,the flame reduction range is 26.71%~28.74%,and the peak value of shock wave overpressure is 14.46%~15.69 %.On this basis,a further study was carried out on the suppression of gas explosion in the cavity composite structure of 500mm*500mm* 200mm-300mm*500mm*200mm(referred to as 55-35 cavity composite structure).The results showed that the peak overpressure reduction of shock wave in the combined structure of 55-35 is 40.08%~40.34%.And the flame reduction range is 43.11%~43.89%.At the same time,the gas explosion suppression experiment was carried out by coupling dry powder of ABC with cavity structure of 55-35,and the explosion suppression effect of 15 g,30g,45 g and 60 g ABC dry powder coupling cavity structure was investigated,respectively.It was found that the flame front attenuation was 54.01%,71.82%,82.77% and 95.84%,respectively.The overpressure attenuation of shock wave peak was 45.75%,51.51%,59.64% and 64.24%,respectively.Compared with the 55-35 cavity,ABC dry powder coupling the combined cavity structure can better inhibit the gas explosion propagation,but its wave suppression effect is not as significant as that of flame suppression.Through theoretical analysis and experimental research,the suppression of gas explosion propagation by cavity structure and ABC dry powder was studied.The obtained experimental data and regular conclusions provide theoretical basis and new ideas for the research and development of gas explosion prevention and suppression devices in coal mines.Figure 48 Table12 References 81...