Oxy-fuel coal combustion, together with carbon capture and storage or utilization, is a set of technologies allowing to burn coal without emitting globe warming CO 2. As it is expected that oxy-fuel combustion may be used for a retrofit of existing boilers, development of a novel oxy-burners is very important step. It is expected that these burners will be able to sustain stable flame in oxy-fuel conditions, but also, for start-up and emergency reasons, in conventional, air conditions. The most cost effective way of achieving dual-mode boilers is to introduce dual-mode burners. Numerical simulations allow investigation of new designs and technologies at a relatively low cost, but for the results to be trustworthy they need to be validated. This paper proposes a workflow for design, modeling, and validation of dual-mode burners by combining experimental investigation and numerical simulations. Experiments are performed with semi-industrial scale burners in 0.5 MW t test facility for flame investigation. Novel CFD model based on ANSYS FLUENT solver, with special consideration of coal combustion process, especially regarding devolatilization, ignition, gaseous and surface reactions, NO x formation, and radiation was suggested. The main model feature is its ability to simulate pulverized coal combustion under different combusting atmospheres, and thus is suitable for both air and oxy-fuel combustion simulations. Using the proposed methodology two designs of pulverized coal burners have been investigated both experimentally and numerically giving consistent results. The improved burner design proved to be a more flexible device, achieving stable ignition and combustion during both combustion regimes: conventional in air and oxy-fuel in a mixture of O 2 and CO 2 (representing dry recycled flue gas with high CO 2 content). The proposed framework is expected to be of use for further improvement of multi-mode pulverized fuel swirl burners but can be also used for independent designs evaluation.

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