Explosion behaviors of hydrogen-nitrous oxide mixtures with propane addition

In the present work, the explosion of hydrogen-propane-nitrous oxide mixtures with various equivalence ratios (& phi; = 0.2-2.4), propane fractions (& omega;C = 0-1.0) and initial pressures (P0 = 50-100 kPa) at ambient temper-ature (288 K, room temperature) was experimentally performed in a standard 3.375-L cubic vessel. The maximum explosion pressure (Pmax), maximum pressure rise rate ((dp/dt)max) and explosion time (te) were ob-tained in light of pressure-time curves, and the normalized maximum explosion pressure (Pmax/P0) and normalized explosion time (td/te) were analyzed as well. Moreover, the adiabatic pressure (Pad) and laminar burning velocity (SL) were also calculated for argumentation. The results indicate that with the increase of & omega;C, Pmax and (dp/dt)max both present three characteristic variation trends for different & phi;, while the inflections of Pmax -& phi; and (dp/dt)max -& phi; transient gradually from lean to rich mixtures. Besides, te and td/te are monotonously rising with & omega;C, illustrating that propane addition can remarkably decelerate the explosion process. In addition, with the increase of P0, Pmax/P0 raises monotonously and is asymptotic to Pad/P0 at & omega;C & LE;0.2, demonstrating that heat loss decreases under higher P0. Linear dependence is also found between (dp/dt)max and P0 for any composition. Furthermore, te monotonically decreases with P0, due to the flame acceleration occurring in the combustion period. In general, the presence of nitrous oxide (N2O) with a large content makes the explosion extremely unstable, and a spot of propane can dramatically alter the explosion characteristics of H2-N2O mix-tures. These results will be meaningful for the development of explosion-mitigation devices and technology in case of underlying explosion and fire hazards.