Fire Safety Science Digital Archive

A mathematical model is formulated here to calculate the time dependent pressures, temperatures, and gas concentrations developed during and following the discharge of carbon dioxide into an enclosure with a known leakage area. The model is based on conservation of mass, energy, and carbon dioxide with assumed spatial distributions of temperature and &on dioxide concentration. The formation and subsequent evaporation of solid phase carbon dioxide, and the cooling of the enclosure walls and floor are determined as part of the solution. Model calculations simulating a series of discharge tests previously conducted in a 993 m³ enclosure are compared to the reported test data. Results show good agreement with concentration data at all times and elevations in the enclosure. Pressures and temperatures show good agreement during the discharge, and somewhat overestimate pressure and temperature recovery following discharge.