Model for Loading Characteristics of Gas Explosion in a Utility Tunnel

Abstract

Gas safety in a utility tunnel is an important scientific problem. In this study, explosion model tests of methane–air mixed gas were conducted to evaluate the safety of the gas. Furthermore, the influences of the concentration of mixed air, ignition mode, and opening area on propagation and distribution law of the blast wave were investigated. The results demonstrated that a significant explosion phenomenon existed if the methane concentration reached 10.5%, manifested by the largest explosion overpressure peak and the highest overpressure growth rate. Flame propagation was accelerated after the explosion under chemical ignition. The overpressure peak was an average of approximately 70% higher than that under the electrode ignition. The explosion overpressure and its impulse can be reduced effectively only for a certain proportion of the tunnel opening area. Therefore, the present study can provide a comprehensive understanding of the loading characteristics and the corresponding mechanism for a gas explosion in various practical tunnels.