Evaluation of a Three-Dimensional Mathematical Model of a Power Station Boiler

A three-dimensional mathematical model based on the numerical solution of the governing equations of mass, momentum, and energy, and transport equations of scalar quantities is presented. The model is applied to a power station boiler of the Portuguese Electricity Utility for which experimental data are available. Predictions of the gas temperature and chemical species concentrations are compared with the measurements. Three different grids were employed to ensure that conclusions are not affected by the grid refinement. It was found that using a combustion model based on the chemical equilibrium assumption, the predicted gas species concentrations are in good agreement with the data and the temperature profiles display the correct trend, although the temperature was under predicted, especially in the burner region. The influence of the air/fuel ratio and power load were also successfully simulated. The present results reveal the predictive capabilities of the model and its usefulness for design or optimization studies.