密闭空间可燃气体爆炸超压预测

In order to avoid damages caused by the explosion of combustible premixed gas in confined space, it is vital to make accurate explosion overpressure prediction in anti-explosion design or daily safety management. Based on the experimental data in literatures, this paper firstly constructd the prediction model of explosion overpressure based on the smooth and laminar flame propagation theory, and then points out it failed to accurately predict the explosion of large-volume confined space. Subsequently we analyzed the instability of flame propagation in large-volume confined space and its resulting frontal wrinkles and turbulent combustion, which greatly increases the surface of the flame front and exhibits self-similar fractal characteristics during flame propagation. Based on the fractal combustion theory and relevant empirical data, we further construct the explosion overpressure prediction model for flammable premixed gas explosion with considering flame wrinkling and turbulent combustion. At the same time, the experimental results are compared. The results demonstrate that the relative errors of experimental and theoretical calculation are 10.4% and 11.1% respectively when the volume of confined space is large, and the peak pressure is estimated by using the explosion overpressure model based on the flame propagation theory of wrinkling and turbulent. The errors are reduced 72.3% and 50.6% than that of the smooth and laminar flame propagation theory explosion overpressure model. The theoretical model established in this paper is in good agreement with the experimental results, and it can meet the needs of structural explosion-resistant design or daily safety management to a certain extent.