Combined inhibition effect of vacuum chamber and inert gas on LPG explosion

Abstract

In order to investigate combined inhibition effect of vacuum chamber and inert gas on Liquefied petroleum gas (LPG) explosion, the explosion experiment was carried out on the self-built gas explosion experiment pipe (L/D = 47.5). The flame propagation and explosion pressure characteristics of LPG were investigated at different vacuum degrees and 10% CO2 volume fraction (VF). The results showed that it is feasible to use a photosensitive solenoid valve to open the vacuum chamber. The Photoreceptor Solenoid Valve can open the vacuum chamber in time; Compared to add only 10% CO2, after installing the vacuum chamber, the maximum pressure peaks were all delayed; The pressure drops rapidly and a short period of negative pressure appeared, and the negative pressure duration becomes shorter as the vacuum degree increases; At various vacuum degrees levels, the maximum pressure peak value occurs at 0.06 vacuum degrees, primarily due to the combined influence of residual fuel quantity, Helmholtz oscillation, and turbulence near the flame front. The Pmax in the pipe and the flame intensity at any position is lower than that when only adding 10% CO2; high vacuum is more conducive to extinguish the flame and increase the thickness of the flame; the pumping effect of the vacuum chamber inhibits the rise of explosion pressure and flame propagation velocity. The combined explosion suppression is more effective on LPG explosions compared to add only 10% CO2. When selecting vacuum degree, it is important to consider the impact of the opening time and different vacuum degree within the vacuum chamber on pressure formation and flame propagation.