Modelling of hazardous chemical gas building ingress and consequence analysis during a leak accident

Leakage of hazardous chemical gases during storage or transport via roadways is a common type of accident that threatens human life. This study built a typical residential building model in rural areas of southern China based on Building Information Model technology. The model was then simplified and employed as a target building to simulate the hazardous gas dispersion around it after a leak accident by means of Computational Fluid Dynamic methods. A dose-response model was combined with a probit function analysis to quantitatively identify the exposure risks for different scenarios. The impacts of source location and ventilation path on the dispersion characteristics were analyzed through comparisons of indoor concentration distributions. In addition, the study also quantified the relationship between individual mortality risk and the source intensity by employing H2S as a source of toxic substances. If the source strength was increased by 2.5 times for the same ventilation path, the corresponding mortality rates can improve from 0.1 to 99%. The findings provide effective information about rapid consequence evaluation after accidental leakage of hazardous chemical gas and could be helpful in proposing effective emergency measures to minimize the exposure risk in roadside buildings.