Variation And Prediction Methods Of The Explosion Characteristic Parameters Of Coal Dust/gas Mixtures

The research shows that most of the explosion accidents in mining areas are often caused by a hybrid mixture of coal dust and gas.Even if the accidents are identified as coal dust explosions or gas explosions,the explosion process usually involves both gas and coal dust.Therefore,research on the explosion characteristics of the hybrid mixture of coal dust and gas is of great significance for preventing coal mine explosion disasters and ensuring coal mine production safety.Based on this,the 20 L spherical explosion container is used to measure the maximum explosion pressure,explosion index,lower explosion limit and other parameters of coal dust / gas hybrid mixture explosion under different concentration ratios.The variation law and formation mechanism of the above parameters are analyzed,and the prediction models of the above parameters are established.The main contents of this paper are as follows:In the present paper,four kinds of coal dust with different components were selected.The hybrid explosion experiments were carried out in a standard 20 L spherical container.According to the experimental results,the change law of the maximum explosion pressure and explosion index of hybrid mixture of coal dust and gas were analyzed.The addition of gas has a more obvious effect on the maximum explosion pressure and explosion index of coal dust with low volatile content.After the addition of gas,the increase in the explosion of coal dust is more significant than that in the maximum explosion pressure,indicating that the effect of gas on the explosion index of coal dust is more obvious.As the gas equivalent ratio in the hybrid mixture of coal dust and gas increases,the maximum explosion pressure of the hybrid mixture increases linearly,and the explosion index increases quadratically.However,at any gas concentration,the maximum explosion pressure and explosion index of coal dust and gas mixtures are lower than single-phase gas but higher than single-phase coal dust.The maximum explosion pressure and index prediction model of the hybrid mixture of coal dust and gas have good applicability to the four kinds of volatile coal dust and gas mixtures in this paper,and the relative error is small.It can be used to predict the maximum explosion pressure and explosion index of the hybrid mixture explosion.Four kinds of coal dust/gas hybrid explosion experiments under the same initial conditions have been studied in a standard 20 L spherical container.The addition of gas can lead to a significant reduction in the lower explosion limit of the coal dust,and the reduction is affected by the volatile content of the coal dust.The lower the volatile content of the coal dust,the greater the reduction.Compared with Le Chatelier’s model and Jiang’s model,the Bartknecht model has better applicability for predicting the lower explosion limits of hybrid mixtures of methane and coal dust.The Bartknecht model is especially more suitable for a hybrid mixture of methane and coal dust with lower volatile content.By correlating the maximum explosion pressure,explosion index and particle size,a new model for predicting the lower limit of the hybrid mixture of coal dust and gas is established.The new model has good agreement with the experimental value and high prediction accuracy,and has good applicability to the prediction of the lower limit of the hybrid mixture explosion.There are 40 pictures,8 tables and 94 references in this paper.