Numerical Modeling of Combustion and Heat Transfer in a Laboratory Scale Glass Melting Furnace

Abstract

Abstract A fully three-dimensional model and computer code has been developed for predicting and analyzing combustion and heat transfer in the combustion space of glass melting furnaces. It is capable of predicting steady state temperature, velocity, and species concentration distributions throughout the combustion chamber and spatially resolving the heat transfer to the surrounding walls and the glass/batch surface. Model predictions are obtained from the solution of coupled conservation equations employing a control volume formulation. The discrete ordinates method along with the weighted-sum-of-gray gases model is used to determine radiative heat transfer to the surfaces enclosing the combustion space and within the flow field. Turbulence is modeled using a high Reynolds number k-ε model. A fast-kinetics, single-step combustion model using an assumed shape clipped Gaussian probability density function is used to determine gas species concentrations. The model predications are compared to test data from a laboratory scale glass furnace simulator at the Institute of Gas Technology. Comparisons of predicted quantities are made for wall temperatures, glass surface heat flux, and exit gas stream temperature. Wall and roof temperatures were predicted on average to within 7 percent and global heat fluxes were with in 10 percent of measured levels. Examples of predicted temperature, velocity, and species concentration are presented.