In the radiant section of cracking furnace

the thermal cracking process is highly coupled with turbulent flow

heat transfer and mass transfer. In this paper

a three-dimensional simulation of propane pyrolysis reactor tube is performed based on a detailed kinetic radical cracking scheme

combined with a comprehensive rigorous computational fluid dynamics (CFD) model. The eddy-dissipation-concept (EDC) model is introduced to deal with turbulence-chemistry interaction of cracking gas

especially for the multi-step radical kinetics. Considering the high aspect ratio and severe gradient phenomenon

numerical strategies such as grid resolution and refinement

stepping method and relaxation technique at different levels are employed to accelerate convergence. Large scale of radial nonuniformity in the vicinity of the tube wall is investigated. Spatial distributions of each radical reaction rate are first studied

and made it possible to identify the dominant elementary reactions. Additionally

a series of operating conditions including the feedstock feed rate

wall temperature profile and heat flux profile towards the reactor tubes are investigated. The obtained results can be used as scientific guide for further technical retrofit and operation optimization aiming at high conversion and selectivity of pyrolysis process.