Experimental and Numerical Study on Deflagration Characteristics of Large-Scale Propane-Air Mixture.

Abstract

Seven deflagration tests of a propane-air mixture were carried out in a 22.5 m3 large-scale chamber. The effects of initial volume, gas concentration, and initial turbulence intensity on deflagration characteristics were analyzed. The main frequency of the explosion wave was quantitatively determined by the combination of the wavelet transform and energy spectrum analysis. The results show that the explosive overpressure is formed by the discharge of combustion products and secondary combustion, and the effects of turbulence and gas concentration on the explosive overpressure are higher than the initial volume. Under the condition of weak initial turbulence, the main frequency of gas explosion wave is between 32.13 and 48.33 Hz. Under strong initial turbulence conditions, the main frequency of the gas explosion wave increases with the increase of overpressure, and the empirical formula of the relationship between the main frequency and overpressure is summarized, which could provide theoretical support for the design of mechanical metamaterials for oil and gas explosion. Finally, the flame acceleration simulator numerical model was calibrated through tests, and the overpressure simulation values were in good agreement with the experimental data. The leakage, diffusion, and explosion of a liquefied hydrocarbon loading station in a petrochemical enterprise were simulated. The lethal distance and explosion overpressure at key buildings are predicted for different wind speed conditions. The simulation results can provide a technical basis for evaluating personnel injury and building damage.