Energy Balance in a Large Compartment Fire. (POSTER ABSTRACTS)
Energy Balance in a Large Compartment Fire. (POSTER
ABSTRACTS)
(101 K)
Hamins, A.; Johnsson, E. L.; Donnelly, M. K.
POSTER ABSTRACTS;
Fire Safety Science. Proceedings. Eighth (8th)
International Symposium. (POSTER ABSTRACTS).
International Association for Fire Safety Science
(IAFSS). September 18-23, 2005, Beijing, China, Intl.
Assoc. for Fire Safety Science, Boston, MA, Gottuk, D.
T.; Lattimer, B. Y., Editor(s), 1616-1616 p., 2005.
Keywords:
fire research; fire safety; fire science; compartment
fires; computational fluid dynamics; fire models; energy
balance; validation
Abstract:
The experiments described here were part of an
international collaborative project to assess and
validate fire computer codes for nuclear power plant
applications. Understanding the distribution of energy
released by a fire is important for testing the accuracy
of computational fire codes, which are used to design
fire protection systems. This poster focuses on one of a
series of experiments (Test 3 in Ref. [1]). Test 3 was
selected as illustrative of the measurement approach
used to track the time-varying enthalpy and its
distribution in a compartment fire. Whereas several
studies have considered the distribution of energy in a
compartment fire, few have quantified measurement
uncertainty, which is essential for model validation. A
goal of the test series was to fully characterize the
experiment and the boundary conditions for subsequent
comparison with fire models. Many measurements were made
before the experiments even began. Compartment leakage,
and the thermal and optical properties of the surface
materials were measured. The combustion properties and
behavior of the test fuel were characterized in a
separate series of experiments that measured the heat of
combustion, the combustion efficiency, the radiative
fraction, and the yields of soot, CO2 and CO in the same
burner as used here. The experiment consisted of a
hydrocarbon spray fire with a heat release rate of
nearly 1 MW, burning in a single compartment 7 m by 22 m
by 4 m high. More than 350 instruments were used to make
measurements. This poster focuses on measurements that
were important to understand the enthalpy balance and
the thermal environment in the compartment, including
measurements of the fuel flow, the vertical profiles of
temperature, the heat release rate via oxygen
consumption calorimetry, the total heat loss to the
compartment walls, ceiling, and floor, and the total
mass and heat fluxes through the compartment door. Other
measurements are described in *Ref. [1] and included the
soot density, the concentrations of O2, CO2 and CO in
the hot gas layer, the compartment pressure, compartment
leakage, the radiative and total heat flux at various
targets in the compartment, surface and core
temperatures of horizontally and vertically oriented
control and power cables, and visible and infrared video
records from multiple perspectives. From these
measurements, it was determined that nearly 72% of the
fire energy went to heat compartment surfaces,
24% escaped through the doorway, and 4% went to heat the
upper layer compartment gases.
REFERENCES: [1] Hamins, A., Maranghides, A., Yang, J.,
Johnsson, E., Donnelly, M., Yang, J., Mulholland, G.,
and Anleitner, R., "Report of Test for the International
Fire Model Benchmarking and Validation Exercise #3."
NIST Special Publication 1013-1, Gaithersburg, MD, 2005.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899