Radiative fraction and optical thickness in large-scale hydrogen-jet fires

The radiative characteristics of large-scale (visible length 1.4–9.1 m) hydrogen jet flames that simulate an accidental leak from a high-pressure hydrogen container were compared with previous experimental and theoretical results for laboratory-scale non-sooting flames. The comparison shows that cor...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the Combustion Institute 2007, Vol.31 (2), p.2565-2572
Main Authors: Molina, Alejandro, Schefer, Robert W., Houf, William G.
Format: Article
Language:English
Subjects:
Carbon dioxide
Carbon monoxide
Combustion
Correlation
Fire control
Fires
Hydrogen flames
Jet flames
Optical thickness
Radiation
Simulation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The radiative characteristics of large-scale (visible length 1.4–9.1 m) hydrogen jet flames that simulate an accidental leak from a high-pressure hydrogen container were compared with previous experimental and theoretical results for laboratory-scale non-sooting flames. The comparison shows that correlations of radiative heat fraction with global residence time need to account for the differences in thermal emittance of combustion gases for different fuels. This correction was found to be particularly important when hydrogen flames were compared to flames with CO 2 as a product specie. Measurements of the radiative heat fraction for CO/H 2, CH 4 and H 2 flames collapse onto one line when plotted against the logarithm of a characteristic residence time weighted by a factor that accounts for differences in the radiative characteristics of combustion gases. The radiative fraction of large-scale jet flames was found to be smaller than that predicted by the correlation obtained for laboratory-scale flames. This was explained by an increase in optical thickness as the flame size increases.
ISSN:1540-7489
1873-2704
DOI:10.1016/j.proci.2006.08.060