Fire performance of flame-retardant polyurethane exterior insulation in dormitory buildings: a numerical simulation

Purpose The purpose of this study is to address the issue that polyurethane (PU) rigid foam, used as building exterior wall insulation, is highly flammable and releases toxic smoke and gas. It aims to evaluate the fire safety performance of flame-retardant PU materials in a realistic dormitory building fire scenario. Design/methodology/approach Ordinary PU and flame-retardant PU materials were prepared. Combined with data obtained from a thermogravimetric analyzer and a cone calorimeter, the combustion parameters of these materials were defined in the fire dynamics simulator (FDS). This was used to numerically simulate a realistic dormitory fire scenario to analyze key fire characteristics, including smoke propagation trends and flame temperature dynamics. Findings When flame-retardant PU is utilized as external wall insulation, the temperature at the staircase entrance remains below 60? within the first 200 seconds of the fire. Concurrently, the carbon monoxide (CO) concentration is maintained within an acceptable range for human exposure. The material effectively isolates heat and oxygen, preventing significant smoke spread within the critical 200-second window, thereby providing crucial time for safe personnel evacuation. Originality/value This study addresses a gap in current research by numerically simulating the application of flame-retardant polyurethane in a realistic dormitory building fire. While many studies focus solely on material properties, this research integrates experimental data from a thermogravimetric analyzer and a cone calorimeter directly into the FDS. It demonstrates the practical value of a newly prepared flame-retardant material in significantly extending the available safe egress time (ASET) by delaying toxic smoke spread and extreme temperature rises, providing vital insights for building fire safety design.