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Multiscale modeling of turbulent combustion and NO x emission in steam crackers
Author(s) -
Habibi A.,
Merci B.,
Heynderickx G. J.
Publication year - 2007
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.11243
Subject(s) - combustion , turbulence , radiative transfer , mechanics , flue gas , large eddy simulation , chemistry , thermodynamics , reynolds averaged navier–stokes equations , heat transfer , thermal radiation , physics , optics , organic chemistry
A 3D RANS simulation of lean premixed turbulent combustion in an industrial scale steam cracking furnace is performed. Turbulence is represented by a renormalization group (RNG) k − ε model, while combustion is modeled with a skeletal mechanism. The eddy dissipation concept (EDC) model is used to account for turbulence/combustion interaction. The turbulent combustion regime is identified as a “thin flame regime with pockets” or a “corrugated flamelet regime”. A weighted sum of gray gases model (WSGGM) is used to account for the gas radiative properties. The radiative transfer equation is solved using the P‐1 and discrete ordinates method in the conservative finite volume formulation. NO x calculations are performed as a postprocessing step, with the flow field, temperature, and species concentrations fixed. The formation of NO through thermal, prompt, and N 2 O intermediate mechanisms is considered. The in situ adaptive tabulation technique is used to decrease the computational time required to treat the combustion chemistry. The effect of radiation models on the predicted furnace wall, tube skin, and flue gas temperature profiles and heat fluxes toward the reactor tubes, as well as on the predicted species and NO concentration profiles and structure of the furnace flames under normal firing conditions, is discussed. © 2007 American Institute of Chemical Engineers AIChE J, 2007