Investigation of propane/air explosion-venting characteristics: influence of venting parameters, prediction model establishment and hazardous condition analysis

Explosion-venting, as an effective measure for controlling explosion hazards, plays a significant role in mitigating the consequences of gas explosion in industrial and civil buildings. To systematically investigate the effects of venting characteristic parameters on the hazardous characteristics of premixed propane/air mixture explosion, a computational fluid dynamics (CFD) model with a vented volume of 63.48 m³ was constructed. The parametric study, model prediction, and hazard analysis were conducted to examine the influence of the opening pressure (P₀), the vent weight (W₀) and the vent area (A₀) on the explosion reaction time (R_t), the peak overpressure (P_c) and the peak temperature (T_c). The results indicated that as P₀ and W₀ increased, R_t showed a gradual decreasing trend (t_min = 0.463 s), while P_c and T_c exhibited an opposite increasing trend (P_max = 23.9 kPa, T_max = 2305 K). Meanwhile, with the increase of A₀, R_t, P_c and T_c initially decreased and then slowly increased. The minimum explosion parameters were achieved when A₀ = 4.00 m² (t_min = 0.455 s, P_min = 7.32 kPa, T_min = 2263 K). Besides, the response surface methodology (RSM) was employed to determine the influence degree of different factors on R_t, P_c and T_c as A₀ > P₀ > W₀. Multi-factor prediction models for R_t, P_c and T_c were established and validated. The study also identified that the positive feedback effect between indoor and outdoor overpressure, but the negative feedback effect between indoor and outdoor flame temperature.