화학공학소재연구정보센터
AIChE Journal, Vol.51, No.10, 2721-2736, 2005
Banded gas and nongray surface radiation models for high-emissivity coatings
The efficiency of the application of high-emissivity coatings on reactor tubes and furnace walls in steam-cracking technology can be evaluated only on the basis of a description of radiative heat transfer infrequency bands. For the flue gases in the furnace, a radiation model is introduced in which the gas emits and absorbs radiation in discrete bands only; for the surfaces a nongray surface approach is applied. First, the influence of the model changes on the calculated radiative energy exchange is evaluated theoretically. Next, different furnace simulations are performed to do a numerical evaluation of the introduction of banded radiation models. The changes in the furnace thermal efficiency, attributed to the application of high-emissivity coatings on furnace walls and tube skins in steam-cracking furnaces, are calculated. (c) 2005 American Institute of Chemical Engineers.