Domestic and industrial energy requirements since the beginning of industrial revolution have been largely met by fossil fuels. This leads to a continuous increase in the Earth's atmosphere of carbon dioxide and other harmful components. Also fossil energy resources decreasing day by day and scientists have turned to new research. In this context alternative energy sources have an important role to reduce dependence on fossil fuels. One of the alternative energy sources is biomass and pellet fuel is one of them. In this study, combustion characteristics of pellet fuel in a model smoke tube boiler at different loading conditions were investigated numerically. As a Computational Fluid Dynamic (CFD) program FLUENT package program was used. Calculations were performed at two dimensional conditions. According to various loading conditions, temperature and stream function contours, velocity vectors, exhaust gas temperatures and efficiencies were investigated and results were discussed.

• Ahn, J., Kim, J.J., (2014). Combustion and heat transfer characteristics inside the combustion chamber of a wood pellet boiler. J Mech Sci Technol 28(2), 789-795.
• Begum, S., Rasul, M., Akbar, D., Cork, D., (2014). An Experimental and Numerical Investigation of Fluidized Bed Gasification of Solid Waste. Energies 7(1), 43.
• Chaney, J., Liu, H., Li, J., (2012). An overview of CFD modelling of small-scale fixed-bed biomass pellet boilers with preliminary results from a simplified approach. Energ Convers Manage 63, 149-156.
• Collazo, J., Porteiro, J., Míguez, J.L., Granada, E., Gómez, M.A., (2012). Numerical simulation of a small-scale biomass boiler. Energ Convers Manage 64, 87-96.
• Dong, W., Blasiak, W., (2001). CFD modeling of ecotube system in coal and waste grate combustion. Energ Convers Manage 42(15–17), 1887-1896.
• Fluent, 2006. Fluent User’s Guide.
• Gómez, M.A., Comesaña, R., Feijoo, M.A.Á., Eguía, P., (2012). Simulation of the Effect of Water Temperature on Domestic Biomass Boiler Performance. Energies 5(4), 1044.
• Klason, T., Bai, X.S., (2007). Computational study of the combustion process and NO formation in a small-scale wood pellet furnace. Fuel 86(10–11), 1465-1474.
• Lee, Y.-W., Ryu, C., Lee, W.-J., Park, Y.-K., (2011). Assessment of wood pellet combustion in a domestic stove. Journal of Material Cycles and Waste Management 13(3), 165-172.
• Pelletsatlas, (2009). English Handbook for Wood Pellet Combustion. European Biomass Industry Association.
• Porteiro, J., Collazo, J., Patiño, D., Granada, E., Moran Gonzalez, J.C., Míguez, J.L., (2009). Numerical Modeling of a Biomass Pellet Domestic Boiler. Energ Fuel 23(2), 1067-1075.
• Sui, J., Xu, X., Zhang, B., Huang, C., Lv, J., (2013). A Mathematical Model of Biomass Briquette Fuel Combustion. Energy and Power Engineering 5, 1-5.
• Sungur, B., Topaloglu, B., Ozcan, H., (2016). Effects of nanoparticle additives to diesel on the combustion performance and emissions of a flame tube boiler. Energy 113, 44-51.
• Zhou, H., Jensen, A.D., Glarborg, P., Jensen, P.A., Kavaliauskas, A., (2005). Numerical modeling of straw combustion in a fixed bed. Fuel 84(4), 389-403.
• Sungur, B., Ozdogan, M., Topaloglu, B., Namli, L. (2017). Technical and Economical Evaluation of Micro-Cogeneration Systems in the Context of Global Energy Consumption. Engineer and Machinery 58(686), 1-20.