Abstract: Abstract: In order to study the influence of ignition position and obstacles on propane air explosion in venting space, a numerical model of propane venting space was established based on CFD software FLACS. The model was verified by propane venting test results, and the calculation results of the numerical model were basically reliable. The verified numerical model is used to further study the effects of igniting position and obstacles on overpressure transients during vented explosions of propane–air mixtures. The results show that: as the distance between ignition position and explosion vent increases, the peak values of Δp1, Δp2 and pmax increase accordingly. The existence of obstacles leads to the intensification of turbulence generated by explosion. Turbulent combustion increases the combustion speed and combustion area, resulting in peak value and pressure rise speed of Δp1 increase. And a new overpressure peak pobstacle is generated in this process. In addition, it was found that the time interval between Δp1 and pobstacle peaks decreases with the increase of the venting pressure, and the two overpressure peaks are easy to merge into a larger overpressure peak.

Key words: propane, vented explosion, igniting position, overpressure loads