Modeling of wood crib fires using a detailed pyrolysis model

Abstract

Wood is a widely used energy source but is dangerous in the case of fires. In this study, a detailed pyrolysis model was used to analyze wood fires. Cellulose, active cellulose, hemicellulose, lignin, char, ash, moisture, and air were the wood components that were considered in this study. Seven flammable gaseous species (cellulose gas, hemicellulose gas, lignin gas, propane, char gas, oxidized product 1, and oxidized product 2) were considered in the detailed pyrolysis model. The wood fire model, using a detailed pyrolysis model, predicted the heat release rate and mass loss rate of the wood close to those of a cone calorimetry experiment, particularly for high external heat fluxes (35, 50, and 65 kW/m2). The wood crib fire was analyzed with a detailed pyrolysis model and the heat release rate (HRR)-based model, and the simulation results were compared with experimental results. The HRR-based fire model could not capture the experimentally measured HRR curves. The wood fire model based on the detailed pyrolysis model was able to predict the flaming stage of the wood crib fire. However, the total heat release was predicted to be lower than that in the experiment, and the fire could not be sustained at the stage where heat release due to char oxidation occurred.