Title: Combustion and heat transfer characteristics at the combustion chamber of an oxy-fuel boiler for CO₂ capturing: a numerical simulation

Authors: Joon Ahn, Hyouck Ju Kim

Addresses: School of Mechanical Engineering, Kookmin University, Seoul 305-343, Korea. ' Energy Efficiency Research Division, Korea Institute of Energy Research, Daejeon 305-343, Korea

Abstract: A 0.5 MW class-oxy-fuel boiler was developed to capture CO₂ from the exhaust gas. Flue gas recirculation (FGR) was adopted to make it possible to retrofit existing facility by changing its burner. A co-axial burner was devised to support three combustion modes, which are conventional air combustion, oxy-fuel combustion and oxy-fuel combustion with FGR. Numerical simulations were conducted for the three combustion modes to study the detailed physics inside the combustion chamber of the boiler. The temperature field obtained from the simulation reproduces the flame structures in general, while the results under-predict the spanwise mixing for the air and FGR modes. The FGR combustion yields similar heat transfer characteristics with the conventional air combustion, which implies the possibility to have a CO₂-free boiler by retrofitting the burner while keeping other parts of the boiler.

Keywords: oxy-fuel combustion; boilers; co-axial burners; CO2; carbon dioxide; carbon capture; heat transfer; exhaust gas; flue gas recirculation; FGR; numerical simulation; temperature; flame structures; burner retrofitting; CFD; computational fluid dynamics.

DOI: 10.1504/PCFD.2011.041026

Progress in Computational Fluid Dynamics, An International Journal, 2011 Vol.11 No.3/4, pp.255 - 260

Published online: 28 Jun 2011 *

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