Effects of initial temperature and pressure on hydrogen explosion venting characteristics: A numerical simulation study

Explosion venting effectively prevents structural damage and reduces the risk of catastrophic events from explosions. This study investigates the effects of initial temperature (300 K–400 K) and pressure (0 kPa–100 kPa) on overpressure, flame characteristics, and venting behavior under stoichiometric conditions to ensure safe hydrogen application under complex conditions. A near-linear inverse relationship was observed between initial temperature and peak venting overpressure, with an approximate 4 % reduction in peak venting overpressure for every 25 K increase, because of the faster energy release. In contrast, increasing the initial pressure significantly raised the peak venting overpressure. Although the initial conditions had minimal impact on the peak venting flow rate, higher temperatures shortened venting durations, while higher pressures extended them. This study reveals a previously underreported phenomenon: the release of unburned hydrogen when the vent opens can trigger a secondary explosion, creating a secondary pressure wave and increasing hazards. These findings contribute to a deeper understanding of the dynamics of hydrogen explosive venting and provide guidance for the safe design of hydrogen energy infrastructures. © 2025 Hydrogen Energy Publications LLC