Case Studies in Chemical and Environmental Engineering (Dec 2022)
Theoretical and experimental analysis of temperature decay along an industrial chimney using analytical and k-ω turbulence models
Abstract
Numerical simulations and analytical calculations were performed to predict the bulk and wall temperatures of hot gases undergoing turbulent flow inside industrial chimneys. The natural convection was numerically simulated using the commercial COMSOL computational fluid dynamics code with Wilcox's k-ω turbulence model on 2D cross-sections of a chimney. Two analytical models, the Cortés and modified lumped models, were used to determine the temperature distribution along the chimney height. The numerical and analytical models were validated with empirical data from a glass furnace chimney. Cross-sectional velocity and temperature profiles were simulated at different chimney heights, along with dimensionless parameters such as the Nusselt number. Good agreement was found between the analytical, numerical and empirical results. The modified lumped model performed particularly well – this model is especially detailed, taking into account the chimney roughness and fouling. It was concluded that the modified lumped model can be used as an analytical model, and the k-ω turbulence model as a numerical simulation model, by designers of industrial chimneys.
