Influence of initial pressure on vented gas explosion in vessel with vent duct

The experiments were performed on safety discharge of gas explosions in a vessel with a vent duct. Pressure variations and the flame development in the duct during the ducted vented explosion process were studied. The influence of initial pressure on the venting process was analyzed. Comparative study of confined explosions, simply vented explosions and ducted vented explosions were conducted. It is shown that peak pressure and the rate of pressure rise increase with the initial pressure for isolated closed explosion. For simply vented explosion, with the increase of initial pressure, the peak pressure increases first, then reduces, and finally increases. For ducted vented explosion process, higher initial pressure results in higher peak pressure, higher rate of pressure rise, higher positive pressure difference, and higher flame speed in duct entrance, and explosion intensity in the vessel is more sensitive to the change of initial pressure. Compared to closed explosion and simply vented explosion, with the increase of initial pressure, the difference between peak pressure for ducted vented explosion process and that for simply vented explosion is getting larger, while the difference between the peak pressure for ducted vented explosion process and that for closed explosion is getting smaller, with the rate of pressure rise obviously higher than that for closed explosion.