Experimental study on the coupling effect of heptafluoropropane and different arrangement of obstacles on methane-air explosion

The influence of heptafluoropropane(CF3CHFCF3) with different barrier arrangements on the prevention of methane-air explosions in semi-closed pipes is examined in this research. Using high-speed photography and pressure sensors, the propagation traits and pressure data of flames were captured on the self-built explosion test platform. The findings demonstrate that, in the absence of barriers, a 1% concentration of CF3CHFCF3 promotes the spread of methane explosions, with an 8.6% reduces in flame propagation time. However, as CF3CHFCF3 concentration rises, the strength of the inhibition of methane explosions weakens with increasing concentration, and at a concentration of CF3CHFCF3 greater than 5%, the explosions are completely inhibited. When barriers of different arrangements are introduced, the inhibition impact of CF3CHFCF3 on methane explosion is improved. In these barriers, the maximum boosting rate and peak explosion overpressure are decreased by 28.81% and 97.27%, respectively. The staggered arrangement of barriers provides a higher coupling effect when the concentration of CF3CHFCF3 is between 1% and 3%, while the symmetrical arrangement of barriers has the optimum coupling effect when the concentration is between 4% and 5%.