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Adiabatic Surface Temperature for Calculating Heat Transfer to Fire Exposed Structures.


pdf icon 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.