Study On Prediction Of Explosion Hazard Of Multi-Component Gases From Coal Spontaneous Combustion

The disasters of coal spontaneous combustion and gas explosion in our country are very serious.A large amount of combustible gas and high-temperature environment produced by coal spontaneous combustion have promoted the gas explosion.Gas explosion accidents caused by spontaneous combustion of coal not only pose a low threat to the lives and health of mine operators but also cause resource loss.In this thesis,the high-temperature programmed temperature experiment and the 20L explosion ball experiment were used to study the explosion hazards of multi-element combustible gases at the ignition point under different oxygen concentrations,and the explosion limit parameters and explosion hazards of different multi-element combustible gas ratios at different temperatures were obtained.And the empirical formula was used to calculate the explosion hazard of the multi-element combustible gas at the characteristic temperature point of coal spontaneous combustion.The research results obtained are as follows:(1)According to the high-temperature program temperature increase experiment,under the oxygen concentration of 21%,15%,and 9%,O2,CO,CO2,CH4,C2H6,C2H4,C2H2,C3H8,C3H6,C3H4,C4H10,and C4H6 gas generation law,and the production rate,the analysis shows that the ignition points at different oxygen concentrations are 340℃,370℃,and 390℃respectively.(2)Under the oxygen supply conditions of 21%,15%,and 9%oxygen concentration,configure multiple combustible gases according to the results of the high-temperature program temperature increase experiment.The explosion experiment test was carried out with a 20L spherical explosion tank at an initial temperature of 30℃ to 150℃,and the results found that the explosion risk of the proportioning gas is the largest under 15%oxygen concentration,2 1%oxygen concentration is the next time,and 9%oxygen concentration is the smallest..This is because hydrocarbon gases containing hydrogen C2 and above have higher explosion limits and higher combustion calorific values than CH4 and CO gases.Therefore,it is necessary to study the risk of gas explosion induced by coal spontaneous combustion with more component gases.(3)Experiments with a 20L explosive ball found that under the condition that the initial temperature is room temperature,with the decrease of oxygen concentration,the explosion limit range is significantly reduced,and the explosion risk is reduced.Empirical formulas are used to calculate the explosion limit of each proportion of gas,and the explosion risk F value and explosion risk of different proportions of gas at characteristic temperature points under different oxygen concentrations are obtained.The increase of the initial temperature increases the range of the gas explosion limit,increases the explosion risk F value,and increases the gas explosion risk.The gas explosion limit fitting formula and empirical formula obtained from experimental tests were used to predict the explosion risk of multi-component combustible gases in the temperature range of 30～390℃,and it was found that the increase in temperature significantly increased the explosion of multi-component gases.The degree of danger and research results have important practical significance for providing the basis and basis for the coordinated prevention and control of coal spontaneous combustion and gas explosion disasters.