Cofiring Coal Slime with Anthracite in a Down-Fired Utility Boiler: Experimental and Numerical Investigations
Publication: Journal of Energy Engineering
Volume 149, Issue 2
Abstract
Cofiring of coal slime in existing utility boilers is a promising approach to the disposal of coal slime. However, reports about cofiring coal slime with anthracite in the down-fired utility boiler are still few. This work presents a comprehensive study on the combustion characteristics, slagging potential, and emissions of cofiring coal slime and anthracite through lab-scale experiments, numerical simulations, and full-scale industrial measurements in a 600MW down-fired utility boiler. The lab-scale experiments show combustion interactions between anthracite and coal slime, which have both a promotive effect on the ignition of anthracite and inhibitive effect on the combustion and burnout of anthracite. Especially, the inhibitive effect is greater than the promotive effect when the blending ratio of coal slime is above 5%. The addition of coal slime can effectively improve the ash fusion temperature of blended samples. In addition, simulations and full-scale industrial measurements of anthracite cofiring with coal slime are performed in a down-fired utility boiler. The results show that as the blending ratio of coal slime increases, the carbon content in fly ash increases and the boiler efficiency and emissions decrease. A 5% ratio is validated to be a reasonable cofiring ratio of coal slime in the actual operation without no slagging phenomenon. These results provide more insights into the cofiring behavior of coal slime and anthracite and guide the application of blending coal slime in a down-fired boiler.
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Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
Acknowledgments
This work was sponsored by China Postdoctoral Science Foundation (2019M652639) and Inter-governmental International Scientific and Technological Innovation Cooperation Project of National Key R&D Program of China (No. 2021YFE0107300).
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Published In
Journal of Energy Engineering
Volume 149 • Issue 2 • April 2023
Copyright
© 2022 American Society of Civil Engineers.
History
Received: Aug 22, 2022
Accepted: Oct 26, 2022
Published online: Dec 29, 2022
Published in print: Apr 1, 2023
Discussion open until: May 29, 2023
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