Prediction of Fire Growth for Compartments of Office Buildings as Part of a Fire Risk/Cost Assessment Model

Abstract

This article presents a zone model for the prediction of fire growth in a commercial compartment of an office building as part of a fire risk and cost assessment software package. The model developed is a combination of a transient, two-zone submodel used for the pre-flashover fire state and a quasi-steady, single-zone submodel for the post-flashover state. In the two-zone submodel, the selected four independent governing variables are pressure, enthalpy of the upper layer, and the masses of the upper and lower layers. To determine the conditions in the fire compartment, the model considers combustion, fluid flow, and heat transfer. The single-zone submodel includes the energy balance equation, and equations of energy losses due to smoke flow, conduction through the compartment walls, and radiation. The article also presents results of model validation using experimental data from tests in a standard room and in an experimental atrium with a smoke exhaust system. Comparisons of smoke, temperature, interface height and smoke flow rates have been conducted. For the data comparison, the differences between experimental and predicted results range from 2 to 16%.