Models for gaseous radiative heat transfer applied to oxy-fuel conditions in boilers
Artikel i vetenskaplig tidskrift, 2010

Models of gas radiation properties have been evaluated for conditions relevant to oxy-fired boilers, characterized by larger pressure path-lengths and possibly different ratios of H2O/CO2 compared to air-fired boilers. Statistical narrow band (SNB) models serve as reference. The other radiation models tested are the weighted-sum-of-grey-gases model, the spectral line-based weighted-sum-of-grey-gases model and two grey-gas approximations. The range of validity of the existing coefficients of the weighted-sum-of-grey-gases model is limited, and new coefficients have therefore been determined to cover the conditions of interest. Several assumed test cases, involving both uniform and non-uniform paths, have been studied to evaluate the accuracy of the models. Comparisons with experimental data are also included. The results show that a grey approximation can give accurate wall fluxes, but at the expense of errors in the radiative source term. The weighted-sum-of-grey-gases model with the new coefficients yields predictions within 20% of those of the reference model in most cases, while the spectral line-based weighted-sum-of-grey-gases model usually gives results within 10%. There are, however, discrepancies between the SNB models at high temperatures. The weighted-sum-of-grey-gases model with its low computational cost is recommended for computationally demanding applications where predictions of both wall fluxes and the radiative source term are important.

Gas radiation





Robert Johansson

Chalmers, Energi och miljö, Energiteknik

Klas Andersson

Chalmers, Energi och miljö, Energiteknik

Bo G Leckner

Chalmers, Energi och miljö, Energiteknik

Henrik Thunman

Chalmers, Energi och miljö, Energiteknik

International Journal of Heat and Mass Transfer

0017-9310 (ISSN)

Vol. 53 1-3 220-230


Annan kemiteknik

Annan fysik



Mer information