Influence of biomass furnace volume change on flue gases burn out process

In this paper has been shown improvement of the existing furnace for biomass combustion in the way of improving energy efficiency and meeting environmental protection criteria. One of the main problems during baled biomass combustion process is high CO emission due to incomplete combustion of flue gases. By proper furnace dimensioning that problem can be avoided and also high investment costs can be reduced, since the cost of the furnace is 30-40% of total biomass plant costs. Two-dimensional turbulent flow model with homogeneous chemical reactions has been developed. Turbulent flow is considered using time averaging Navier-Stokes equations that are closed by k-ε turbulence model. Calculations based on the proposed models were conducted using commercial CFD package FLUENT. Accuracy of the model has been previously confirmed with experimental data obtained on the existing furnace. Comparative analysis of the results of modeling existing and proposed (improved) furnace has shown lower CO emission (more than 50% less CO emission) at the proposed furnace outlet.