Effects of explosion-venting interlayer height on methane explosion dynamics in utility tunnels

Alongside the increasingly widespread use of utility tunnels, the risk of gas compartment explosions poses a significant threat to public safety. This study experimentally investigates the effects of explosion-venting interlayer height on methane explosion dynamics and pressure-relief efficiency, aiming to optimize the explosion venting design of utility tunnels. The results indicate that increasing the height of the explosion-venting interlayer remarkably suppresses flame propagation and explosion overpressure, while also playing a crucial role in regulating pressure-relief efficiency. A 30 mm interlayer height effectively balances energy release efficiency and demonstrates the most effective suppression of flame velocity. Increasing the height of the interlayer enhances the suppression of explosion overpressure, with Case c1 achieving the best suppression effect at 11.55 kPa. Additionally, positioning an explosion vent near the ignition source can mitigate explosions through early intervention. The synergistic effect of porous materials and the interlayer can disrupt the flame front, absorb shock wave energy, and enable flameless venting and heat dissipation. Optimizing the height of the explosion-venting interlayer and the layout of the explosion vent can significantly improve the explosion safety performance of utility tunnels. This research offers a theoretical foundation for designing explosion protection in utility tunnels and forms a foundation for practical engineering application.