New Temperature Correlation for Forced-Ventilated Compartment Fires

摘要

Forced-ventilated compartments are a common environment for fire growth in sealed or high-rise structures. Currently, no method exists for reliably estimating the fire hazard in these enclosures. Using data from compartment fires in the forced-ventilation facility at Lawrence Livermore National Laboratory (LLNL), a simple correlation has been developed following the methods of McCaffrey, Quintiere, and Harkleroad. The upper-layer temperature rise above ambient, delta T = T/sub u/ - T/sub infinity/, is given as a function of the fire heat-release rate, Q, the compartment mass-ventilation rate, m, the gas specific-heat capacity, c/sub p/, the compartment surface area, A/sub W/, and an effective heat-transfer coefficient based on t and h/sub k/. The nondimensional form of the best fit to the data is delta T/T/sub infinity/ = 0.63 (Q/mc/sub p/T/sub infinity/)/sup 0.72/ (h/sub k/A/sub W//mc/sub p/)/sup -0.36/. This confirms the correlation suggested by McCaffrey, et al. For their free-ventilation data, the coefficient increases to 0.77. All data are well fit by a coefficient of 0.7, while the powers remain unchanged. Alternatives for, limits, on, and the usefulness of such correlations are discussed. (ERA citation 11:038831)