Analysis of Compartment Fires with a Ceiling Vent

Abstract

The fire behaviors in a compartment only with a single ceiling vent at the corner were investigated experimentally and the effects of vent size and fuel surface area on the fire development were studied in detail. The compartment was 1 m (W) × 1 m (L) × 0.75 m (H) and the area of the ceiling vent varied in six dimensions. Fire source was n-heptane pool with three different diameters, 0.1 m, 0.141 m and 0.2 m, respectively. The fuel mass loss rate, gas temperature profile and oxygen concentration in the compartment were measured and flame behaviors were recorded by a video camera. The results showed that flame extinctions were due to two factors, oxygen concentration and fuel quantity. The ceiling vent only had a small impact on the mass loss rate and gas temperature profile when the fire extinction was due to low oxygen concentration. Additionally, mass loss rates showed same values when compared to free mass loss rate for small fires, even the fire was self-extinction. The effects of oxygen concentration and hot gas temperature on mass loss rate were examined and its solution agrees well with the measurements.