Large hydrocarbon fuel pool fires: physical characteristics and thermal emission variations with height

In a recent paper [P.K. Raj, Large LNG fire thermal radiation-modeling issues and hazard criteria revisited, Process Safety Progr., 24 (3) (2005)] it was shown that large, turbulent fires on hydrocarbon liquid pools display several characteristics including, pulsating burning, production of smoke, and reduced thermal radiation, with increasing size. In this paper, a semi-empirical mathematical model is proposed which considers several of these important fire characteristics. Also included in this paper are the experimental results for the variation of the fire radiance from bottom to top of the fire (and their statistical distribution) from the largest land spill LNG pool fire test conducted to date. The purpose of the model described in this paper is to predict the variation of thermal radiation output along the fire plume and to estimate the overall thermal emission from the fire as a function its size taking into consideration the smoke effects. The model utilizes experimentally measured data for different parameters and uses correlations developed from laboratory and field tests with different fuels. The fire dynamics and combustion of the fuel are modeled using known entrainment and combustion efficiency parameter values. The mean emissive power data from field tests are compared with model predictions. Model results for the average emissive powers of large, hypothetical LNG fires are indicated.