Experimental and numerical study of pool fire dynamics in an air-tight compartment focusing on pressure variation

Abstract

The present paper studies the fire-induced pressure evolution in an air-tight compartment. Two cases with different sizes (i.e., 0.3 m × 0.3 m and 0.5 m × 0.5 m) of square methanol pool fire are considered. Repeated tests were performed for each case, leading to a total of four fire experiments. The leakage of the compartment is measured under different pressure conditions in order to obtain the relationship between the leakage and the pressure increase. The pressure inside the compartment reaches peak values of 133 Pa and 697 Pa for the small and the large pool fire, respectively. Simulation results using the Fire Dynamics Simulator (FDS) 6.5.3 match well with experiments. The simulated leakage flow rates, which reach values up to 65 m3/h and 200 m3/h, respectively, depend on the pressure variation and leakage settings. The pressure rises strongly in the growth phase of the fire, in line with a rapid increase in fire heat release rate. The gradually increasing heat losses subsequently lead to a decrease in pressure.