Adiabatic Surface Temperature for Calculating Heat Transfer to Fire Exposed Structures.
Adiabatic Surface Temperature for Calculating Heat
Transfer to Fire Exposed Structures.
(956 K)
Wickstrom, U.; Duthinh, D.; McGrattan, K. B.
Volume 2;
Interflam 2007. (Interflam '07). International
Interflam Conference, 11th Proceedings. Volume 2.
September 3-5, 2007, London, England, 943-953 pp, 2007.
Keywords:
fire resistance; structures; surface temperature; heat
transfer; solids; fire safety; safety engineering;
temperature; equations; load bearing capacity;
experiments; steels; insulation; compartment fires;
World Trade Center; fire models
Abstract:
A basic and common understanding of heat transfer to
solids is very important for the advancement of fire
safety engineering in areas such as the prediction of
the temperature and load bearing capacity of structural
components as well as the burning behaviour of real
materials. However, because researchers and test
standard developers have different ways of expressing
and measuring the various forms of convective and
radiative heat flux, confusion often arises. This paper
is intended to address this issue. The new concept of
adiabatic surface temperature is introduced as a
practical means to express the thermal exposure of a
surface. The concept is particularly useful when
calculating temperatures in fire exposed structures, as
is shown in this paper. It can be used successfully when
the exposure conditions are obtained either from a fire
model or directly from measurements. In the latter case,
the so called plate thermometer (PT), defined in the
fire resistance standards ISO 834 or EN 1363-1, may be
employed. This implies that the temperature of
structural components tested according to these
standards may be predicted using the plate thermometer
measurements which are inherently designed to follow
specified time-temperature curves.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899