Study on Overpressure Propagation Law of Vapor Cloud Explosion under Different Building Layouts

To determine and optimize the emergency evacuation path of personnel in the case of vapor cloud explosion caused by pipeline leakage and improve the safety control measures in the high-consequence areas of gas pipelines, this study was conducted. This work mainly studied two questions: whether various research methods applicable to the solid explosive explosion are also applicable to vapor cloud explosion and the influence of different building layouts on the overpressure propagation law of vapor cloud explosion. First, the applicability of several empirical models and computational fluid dynamics (CFD) methods in vapor cloud explosion overpressure prediction is systematically compared and analyzed. Second, the finite element models based on the fluid–structure interaction are established to study the overpressure propagation law under the influence of different building layouts. Finally, based on the overpressure propagation law, the determination and optimization principle of the emergency evacuation path of personnel when an accident occurs are given. The results show that the CFD method and empirical model based on equivalent assumption between trinitrotoluene and combustible gas are not suitable for the study of gas-phase explosion, while the mixed gas method based on CFD is more suitable for exploring the overpressure problem of vapor cloud explosion. Buildings arranged perpendicular to the direction of blast wave have the most obvious enhancement and weakening effect on overpressure, and the maximum increase rate and decrease rate are about 90%. The maximum increase rate of overpressure between two vertical layout buildings is more than 60% higher than that between two horizontal layout buildings. When determining the emergency evacuation path, the non-explosive side of the building perpendicular to the shock wave layout should be given priority. If it is necessary to pass through the building gap, the gap between the two horizontal layout buildings should be preferred to ensure that the damage of overpressure to personnel is minimized. The research results can provide a theoretical basis for the improvement of personnel safety control measures in high-consequence areas of the gas pipeline.