Development of a CFD Model of a Pellet Stove for Accurate Prediction of Flame Temperature and Emissions

Pellet stoves are widely used for domestic heating but remain significant sources of air pollutants, including carbon monoxide, nitrogen oxides, and particulate matter. To reduce these emissions, a 3D numerical model was developed in ANSYS Fluent to simulate the combustion of wood pellets in a commercial stove. The model combines a simplified reaction mechanism to limit the number of species with detailed modeling of turbulence, heat transfer, and thermal radiation. An explicit DEM-based representation of the pellet bed, a nongray radiative heat transfer model based on multiband gas absorption coefficients coupled with a Monte Carlo solver, was implemented. Empirical parameters of the combustion-turbulence interaction model were adjusted to fit the experimental temperatures. The model was able to predict the composition of the flue gases measured from two different stoves with satisfactory agreement, in terms of both the main species (O₂ and CO₂) and pollutants (CO and NO _x ). These results demonstrate the potential of the developed numerical model as a predictive tool to improve stove design and reduce the environmental impact of small-scale furnaces.