Oxy-coal Combustion Modeling at Semi-industrial Scale
The use of simulation tools such as CFD leads to a detailed fundamental understanding of the complex processes during coal combustion. Thus, mathematical modeling provides an important instrument for research and development of the oxy-coal combustion technology which represents one of the promising CO2 capture and storage (CCS) technologies. In this process, coal is burnt in an atmosphere consisting of pure O2 mixed with recycled flue gas leading to an exhaust gas with high CO2 concentration which is ready for storage after further conditioning. However, the specific conditions of the oxy-coal combustion process require several adjustments in the CFD code which was originally been developed for conventional air-firing combustion. Accordingly, advanced sub-models concerning global homogeneous and heterogeneous chemistry as well as gas phase radiation have been developed and implemented in IFK’s CFD code AIOLOS.
The objective of this study was to investigate the accuracy and prediction quality of the enhanced modeling approach. The simulation results focus on temperature profiles and gas species concentrations. For validation purposes extensive tests have been carried out at IFK’s semi-industrial scale furnace (500 kWth) firing dried pulverized lignite. In general, the simulation results show satisfactory agreement to the corresponding measurements indicating that the developed mathematical models are suitable for the application of the AIOLOS code in the field of oxy-coal combustion.
KeywordsRadiative Heat Transfer Radiative Transfer Equation Computational Fluid Dynam Code Swirl Burner Oxyfuel Combustion
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- 8.U. Schnell, Numerical modelling of solid fuel combustion processes using advanced CFD-based simulation tools, Progress in Computational Fluid Dynamics 1 (4) (2001) 208–218. Google Scholar
- 9.D. Förtsch, A Kinetic Model of Pulverised Coal Combustion for Computational Fluid Dynamics, Ph.D. thesis, Universität Stuttgart, Stuttgart (2003). Google Scholar
- 10.J. Ströhle, Spectral Modelling of Radiative Heat Transfer in Industrial Furnaces, Shaker Verlag, Aachen, 2003. Google Scholar
- 11.L. Al-Makhadmeh, Coal Pyrolysis and Char Combustion Under Oxy-Fuel Conditions, Shaker Verlag, Aachen, 2009. Google Scholar
- 13.S. Leiser, Numerical Simulation of Oxy-Fuel Combustion, Shaker Verlag, Aachen, 2010. Google Scholar
- 14.E. W. Lemmon, M. O. McLinden, D. G. Friend, NIST Chemistry WebBook (2009). Google Scholar
- 18.T. Wall, Y. Liu, C. Spero, L. Elliott, S. Khare, R. Rathnam, F. Zeenathal, B. Moghtaderi, B. Buhre, C. Sheng, R. Gupta, T. Yamada, K. Makino, J. Yu, An overview on oxyfuel coal combustion – State of the art research and technology development, Chemical Engineering Research and Design 87 (2009) 1003–1016. CrossRefGoogle Scholar
- 19.H. C. Hottel, A. F. Sarofim, Radiative Heat Transfer, McGraw-Hill, New York, 1967. Google Scholar
- 25.S. Grathwohl, O. Lemp, U. Schnell, J. Maier, G. Scheffknecht, F. Kluger, B. Krohmer, P. Mönckert, G. N. Stamatelopoulos, Highly Flexible Burner Concept for Oxyfuel Combustion, in: 1st Oxyfuel Combustion Conference, Cottbus, Germany, 2009. Google Scholar