Experimental and theoretical research on flame emissivity and radiative heat flux from heptane pool fires

Author: Ji, J., Ge, F. L., Qiu, T. T.

Journal: Proceedings of the Combustion Institute

DOI: 10.1016/j.proci.2020.05.052

Keywords: Pool fires, Flame emissivity, Radiative heat flux, Solid flame model, turbulent-diffusion flames, thermal-radiation, temperature, behaviors, model

Abstract: 

This paper presents an experimental investigation on the flame radiation characteristics of pool fire, including the flame emissivity, diameter and temperature. A series of experiments of heptane pool fires with diameters of 0.1-0.4 m were carried out. The flame height, mass loss rate, temperature distribution, flame emissivity and radiative heat flux were measured. A four regions function was used to correlate the centerline temperature rise above the pool surface with the flame height. The variations of the flame diameter against the flame height were formulated for D > 0.2 m and D <= 0.2 m respectively. The highest flame emissivity is found at the flame base, which decreases with increasing height. Furthermore, a new model predicting the radiative heat flux based on classical solid flame model is developed taking into account the flame emissivity, diameter and temperature variations along the flame height. The comparisons between the new model and other models show that the new model can better predict the thermal radiation from heptane pool fires. (c) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.