Advanced technical assessment of 40 MW large-scale calorimeter in full-scale n-Heptane pool fire testing: Precision measurement and analysis

Abstract Accurate heat release rate (HRR) measurements are essential for characterizing fire safety in various engineering structures or buildings, particularly in high-risk environments such as railway vehicles and warehouses. In this study, a large-scale calorimeter was developed for high-intensity fires up to 40 MW, tailored for validating full-scale fire tests in the railway vehicle and warehouse industries. Cold and hot flow field calibrations were conducted using n-heptane pool fires to assess the calorimeter’s performance and accuracy. Results from the cold flow calibration revealed that the volume flow rate and pressure differential in the exhaust duct remained stable and uniform across varying exhaust fan frequencies. The total heat release and theoretical total heat release value were compared and the error was analyzed separately in the process of the hot flow field calibration. Validation tests using multiple n-heptane pool fires confirmed the calorimeter’s capability, with a maximum measurable HRR of 37.8 MW and a testing error of -9.4%, well within the standard error range of ±10%. Additionally, the 40 MW calorimeter has been successfully applied to high-intensity warehouse fire tests. This study provides valuable insights for the application of large-scale calorimeters in fire science and engineering, offering a vital platform for accurate HRR measurements in diverse fire scenarios especially for high intensity fire. The findings are particularly relevant for the design and assessment of fire-resistant materials and structures, contributing to the advancement of fire safety in the construction industry.