Thermal radiation from vertical jet fires

Geometric and thermal data, obtained from a series of large outdoor jet fire experiments, were used to estimate the thermal radiation intensity from the flames towards targets located at diverse distances. Vertical turbulent sonic and subsonic exit velocity propane jet fires, up to 10.3 m in length released in still air, were studied. The temperatures of the flame surface and the surface emissive power of the flame were also analysed by processing infrared images. Thermal radiation intensity was estimated by applying the solid flame model in both one-zone and multiple-zone configurations (taking into account the variation of surface emissive power), considering the flame as a cylinder defined by the 800 K isotherm. Experimental and predicted thermal radiation intensity values were compared.

► The thermal radiation behaviour of propane jet fires is studied. ► Thermal radiation can be a significant thread at short distances. ► One-zone and three-zone models for estimating the thermal radiation are compared.