Numerical Investigation of a Coal-Fired Power Plant Main Furnace under Normal and Reduced-Oxygen Operating Conditions
Publication: Journal of Energy Engineering
Volume 143, Issue 5
Abstract
This work simulates the Suralaya Power Plant Unit 6 boiler located at Cilegon, Banten, in Indonesia for two thermal loads, i.e., 600 and 400 MW under as-found (normal) and reduced-oxygen conditions, by means of computational fluid dynamics (CFD) using a sophisticated software package. The reduced-oxygen condition is an operational scheme that assumes lower mass flow rates of injected air and fuel compared with the as-found ones, but constant or slightly improved thermal efficiency with lower NOx emissions. The results of the CFD simulation were compared against thermodynamic results in the as-found condition cases regarding the overall heat flux and the species concentration, and overall show good agreement because the maximum percentage difference is approximately 14.5% regarding the mole fraction in the 400-MW case. In general, the differences between the two subcases of each investigated thermal load are slight concerning the total heat transfer, the spatial distribution of the heat flux values, the emissions, and the overall char burnout. More important differences can be noted regarding the CO emissions because the mass and molar concentrations at the main furnace outlet surface almost double in the case of reduced-oxygen conditions in comparison with the case of the as-found ones. Furthermore, it is noted that in all four examined cases the front side of the boiler experiences the highest heat flux values among the boiler tube wall sides. This is attributed to the developed velocity field due to the inclined configuration of the rear boiler tube walls at the proximity of the main furnace outlet surface. In order to minimize the thermal loading of the front side walls and reduce the CO emissions, it would be beneficial to implement a more suitable swirl in the secondary air inlet ports and the development of an overfire air (OFA) system.
Get full access to this article
View all available purchase options and get full access to this article.
References
Agraniotis, M., Nikolopoulos, N., Nikolopoulos, A., Grammelis, P., and Kakaras, E. (2010). “Numerical investigation of solid recovered fuels’ co-firing with brown coal in large scale boilers—Evaluation of different co-combustion modes.” Fuel, 89(12), 3693–3709.
Al-Abbas, A. H., Naser, J., and Dodds, D. (2012). “CFD modelling of air-fired and oxy-fuel combustion in a large-scale furnace at Loy Yang a brown coal power station.” Fuel, 102, 646–665.
Al-Abbas, A. H., Naser, J., Dodds, D., and Blicblau, A. (2013). “Numerical modelling of oxy-fuel combustion in a full-scale tangentially-fired pulverised coal boiler.” Procedia Eng., 56, 375–380.
ANSYS Version 15.0.0 [Computer software]. ANSYS, Canonsburg, PA.
Badzioch, S., and Hawksley, P. G. W. (1970). “Kinetics of thermal decomposition of pulverized coal particles.” Ind. Eng. Chem. Process Des. Dev., 9(4), 521–530.
Bhuiyan, A. A., and Naser, J. (2015). “CFD modelling of co-firing of biomass with coal under oxy-fuel combustion in a large scale power plant.” Fuel, 159, 150–168.
Bhuiyan, A. A., and Naser, J. (2016). “Thermal characterization of coal/straw combustion under air/oxy-fuel conditions in a swirl-stabilized furnace: A CFD modelling.” Appl. Therm. Eng., 93, 639–651.
Black, S., et al. (2013). “Effects of firing coal and biomass under oxy-fuel conditions in a power plant boiler using CFD modelling.” Fuel, 113, 780–786.
Bruce, A. R. W., Harrison, G. P., Gibbins, J., and Chalmers, H. (2014). “Assessing operating regimes of CCS power plants in high wind and energy storage scenarios.” Energy Procedia, 63, 7529–7540.
Díez, L. I., Cortés, C., and Pallarés, J. (2008). “Numerical investigation of NOx emissions from a tangentially-fired utility boiler under conventional and overfire air operation.” Fuel, 87(7), 1259–1269.
Filkoski, R. V., Petrovski, I. J., and Karas, P. (2006). “Optimization of pulverised coal combustion by means of CFD/CTA modeling.” Therm. Sci., 10(3), 161–179.
Graus, W., Roglieri, M., Jaworski, P., and Alberio, L. (2008). “Efficiency and capture-readiness of new fossil power plants in the EU.” Ecofys Netherlands, Utrecht, Netherlands.
Gubba, S. R., et al. (2012). “Numerical modelling of the co-firing of pulverised coal and straw in a 300MWe tangentially fired boiler.” Fuel Process. Technol., 104, 181–188.
Guo, J., et al. (2015). “Numerical investigation on oxy-combustion characteristics of a 200MWe tangentially fired boiler.” Fuel, 140, 660–668.
Habib, M. A., Ben-Mansour, R., Badr, H. M., Ahmed, S. F., and Ghoniem, A. F. (2012). “Computational fluid dynamic simulation of oxyfuel combustion in gas-fired water tube boilers.” Comput. Fluids, 56, 152–165.
Hammond, G. P., and Spargo, J. (2014). “The prospects for coal-fired power plants with carbon capture and storage: A UK perspective.” Energy Convers. Manage., 86, 476–489.
Karampinis, E., Nikolopoulos, N., Nikolopoulos, A., Grammelis, P., and Kakaras, E. (2012). “Numerical investigation Greek lignite/cardoon co-firing in a tangentially fired furnace.” Appl. Energy, 97, 514–524.
Kuang, M., Zhu, Q., Li, Z., and Zhang, X. (2013). “Numerical investigation on combustion and NOx emissions of a down-fired 350 MWe utility boiler with multiple injection and multiple staging: Effect of the air stoichiometric ratio in the primary combustion zone.” Fuel Process. Technol., 109, 32–42.
Kyritsis, D., Rakopoulos, C., and Rakopoulos, D. (2014). “Special issue on contemporary combustion experimentation and modeling for clean and efficient power generation: Issues and challenges.” J. Energy Eng., C2014001.
Li, J., Brzdekiewicz, A., Yang, W., and Blasiak, W. (2012). “Co-firing based on biomass torrefaction in a pulverized coal boiler with aim of 100% fuel switching.” Appl. Energy, 99, 344–354.
Liu, G., Chen, Z., Li, Z., Li, G., and Zong, Q. (2015). “Numerical simulations of flow, combustion characteristics, and NOx emission for down-fired boiler with different arch-supplied over-fire air ratios.” Appl. Therm. Eng., 75, 1034–1045.
Liu, Y., Fan, W., and Li, Y. (2016). “Numerical investigation of air-staged combustion emphasizing char gasification and gas temperature deviation in a large-scale, tangentially fired pulverized-coal boiler.” Appl. Energy, 177, 323–334.
Lucquiaud, M., Fernandez, E. S., Chalmers, H., Dowell, N. M., and Gibbins, J. (2014). “Enhanced operating flexibility and optimised off-design operation of coal plants with post-combustion capture.” Energy Procedia, 63, 7494–7507.
Ma, Z., et al. (2007). “A comprehensive slagging and fouling prediction tool for coal-fired boilers and its validation/application.” Fuel Process. Technol., 88(11–12), 1035–1043.
MacDonald, M., Chadwick, M., and Aslanian, G. (2009). The environmental management of low-grade fuels, Taylor & Francis, Hoboken, NJ.
Masseran, N. (2015). “Markov chain model for the stochastic behaviors of wind-direction data.” Energy Conv. Manage., 92, 266–274.
Morsi, S. A., and Alexander, A. J. (1972). “An investigation of particle trajectories in two-phase flow systems.” J. Fluid Mech., 55(2), 193–208.
Nikolopoulos, N., et al. (2013). “Parametric investigation of a renewable alternative for utilities adopting the co-firing lignite/biomass concept.” Fuel, 113, 873–897.
Nikolopoulos, N., Nikolopoulos, A., Karampinis, E., Grammelis, P., and Kakaras, E. (2011). “Numerical investigation of the oxy-fuel combustion in large scale boilers adopting the ECO-scrub technology.” Fuel, 90(1), 198–214.
Pallarés, J., Gil, A., Cortés, C., and Herce, C. (2009). “Numerical study of co-firing coal and Cynara cardunculus in a 350 MWe utility boiler.” Fuel Process. Technol., 90(10), 1207–1213.
Panagiotidis, I., Vafiadis, K., Tourlidakis, A., and Tomboulides, A. (2015). “Study of slagging and fouling mechanisms in a lignite-fired power plant.” Appl. Therm. Eng., 74, 156–164.
Panagiotis, D., Athanasios, N., Nikolaos, N., Aristeidis, N., Dimitrios, R., and Emmanouil, K. (2015). “Numerical investigation of NOx emissions for a flexible Greek lignite-fired power plant.” J. Energy Eng., E4015016.
Park, H. Y., Baek, S. H., Kim, Y. J., Kim, T. H., Kang, D. S., and Kim, D. W. (2013). “Numerical and experimental investigations on the gas temperature deviation in a large scale, advanced low NOx, tangentially fired pulverized coal boiler.” Fuel, 104, 641–646.
Rakopoulos, C., Kakaras, E., Kyritsis, D., and Rakopoulos, D. (2016). “Advanced combustion and fuel technologies for economical and environmentally friendly power generation in engines and power plants: Issues and challenges.” J. Energy Eng., E2016001.
Saha, M., Dally, B. B., Medwell, P. R., and Chinnici, A. (2016). “Burning characteristics of Victorian brown coal under MILD combustion conditions.” Combust. Flame, 172, 252–270.
Saha, M., Dally, B. B., Medwell, P. R., and Chinnici, A. (2017). “Effect of particle size on the MILD combustion characteristics of pulverised brown coal.” Fuel Process. Technol., 155, 74–87.
Schaffel-Mancini, N., Mancini, M., Szlek, A., and Weber, R. (2010). “Novel conceptual design of a supercritical pulverized coal boiler utilizing high temperature air combustion (HTAC) technology.” Energy, 35(7), 2752–2760.
Stupar, G., Tucaković, D., Živanović, T., and Belošević, S. (2015). “Assessing the impact of primary measures for NOx reduction on the thermal power plant steam boiler.” Appl. Therm. Eng., 78, 397–409.
Szuhánszki, J., et al. (2013). “Evaluation of the performance of a power plant boiler firing coal, biomass and a blend under oxy-fuel conditions as a capture technique.” Energy Procedia, 37, 1413–1422.
Taha, T. J., Stam, A. F., Stam, K., and Brem, G. (2013). “CFD modeling of ash deposition for co-combustion of MBM with coal in a tangentially fired utility boiler.” Fuel Process. Technol., 114, 126–134.
Tamura, M., Watanabe, S., Kotake, N., and Hasegawa, M. (2014). “Grinding and combustion characteristics of woody biomass for co-firing with coal in pulverised coal boilers.” Fuel, 134, 544–553.
Tigges, K. D., et al. (2009). “Conversion of existing coal-fired power plants to oxyfuel combustion: Case study with experimental results and CFD-simulations.” Energy Procedia, 1(1), 549–556.
World Coal Association. (2014). “Coal facts 2014.” ⟨http://www.worldcoal.org/bin/pdf/original_pdf_file/coal_facts_2014(12_09_2014).pdf⟩ (Nov. 20, 2016).
Yin, C. (2013). “Refined weighted sum of gray gases model for air-fuel combustion and its impacts.” Energy Fuels, 27(10), 6287–6294.
Zhou, H., Mo, G., Yang, Y., Si, D., and Cen, K. (2014). “Numerical investigation of gas-solid two-phase flow in a tiny-oil ignition cyclone burner for a 300-MW down-fired pulverized coal-fired boiler.” J. Energy Eng., 04013010.
Information & Authors
Information
Published In
Journal of Energy Engineering
Volume 143 • Issue 5 • October 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Dec 3, 2016
Accepted: Apr 12, 2017
Published online: Jul 13, 2017
Published in print: Oct 1, 2017
Discussion open until: Dec 13, 2017
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.