THERMAL SCIENCE

International Scientific Journal

Rastko D. Jovanović

,

Krzysztof Strug

,

Bartosz Swiatkowski

,

Sławomir Kakietek

,

Krzysztof Jagiełło

,

Dejan B. Cvetinović

EXPERIMENTAL AND NUMERICAL INVESTIGATION OF FLAME CHARACTERISTICS DURING SWIRL BURNER OPERATION UNDER CONVENTIONAL AND OXY-FUEL CONDITIONS

ABSTRACT
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 CO2. 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 MWt 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, NOx 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 O2 and CO2 (representing dry recycled flue gas with high CO2 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. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III42010 and Grant no.TR33050]
KEYWORDS
pulverized coal, swirl burners, oxy-fuel, dual-mode burner stability, CFD modeling
PAPER SUBMITTED: 2016-11-10
PAPER REVISED: 2016-12-20
PAPER ACCEPTED: 2016-12-22
PUBLISHED ONLINE: 2017-01-14
DOI REFERENCE: https://doi.org/10.2298/TSCI161110325J
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2017, VOLUME 21, ISSUE Issue 3, PAGES [1463 - 1477]
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Experimental and numerical investigation of flame characteristics during swirl burner operation under conventional and oxy-fuel conditions

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence