THERMAL SCIENCE

International Scientific Journal

NUMERICAL SIMULATION OF NOX EMISSION CHARACTERISTICS DURING COMBUSTION IN 350 MW SUPERCRITICAL COGENERATION TANGENTIALLY BOILER

ABSTRACT
In light of a 350 megawatt supercritical cogeneration tangential boiler, the combustion and the nitrogen oxides release mechanism in the furnace were numerically simulated. The combustion characteristics were analyzed, and the influencing factors, such as the pulverized coal concentration, the velocity of separated over-fire air and the boiler load, on nitrogen oxides release in the furnace were also systematically studied. The results show that the central airflow in the furnace rises spirally, and an inverted “V” type temperature distribution is formed. The generation of nitrogen oxides can be effectively restrained by increasing the concentration of pulverized coal properly. Compared with the conventional concentration, the concentration of nitrogen oxides at the furnace exit can be reduced by 29.63% by taking high pulverized coal concentration. The concentration of NOx at the furnace exit can be drastically reduced by increasing the velocity of separated over-fire air. When decreasing boiler load, the concentration of NOx at furnace exit declines at first and then increases.
KEYWORDS
PAPER SUBMITTED: 2019-10-10
PAPER REVISED: 2019-11-22
PAPER ACCEPTED: 2019-12-09
PUBLISHED ONLINE: 2020-01-19
DOI REFERENCE: https://doi.org/10.2298/TSCI191010006W
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2020, VOLUME 24, ISSUE 5, PAGES [2717 - 2728]
REFERENCES
  1. Korytnyi E, et al., Computational fluid dynamic simulations of coal-fired utility boilers: An engineering tool, Fuel, 88 (2009), 1, pp. 9-18
  2. Agraniotis M, et al., Numerical investigation on the combustion behaviour of pre-dried Greek lignite, Fuel, 88 (2009), 12, pp. 2385-2391
  3. Shen Y S, et al., A three-dimensional numerical study of the combustion of coal blends in blast furnace, Fuel, 88 (2009), 2, pp. 255-263
  4. SONG Y.H, et al., Nitric Oxide Formation during Pulverized Coal Combustion, Combustion Science and Technology, 28 (1982), 1, pp. 37-39
  5. Agraniotis M, et al., Experimental investigation on the combustion behaviour of pre-dried Greek lignite, Fuel, 90 (2009), 9, pp. 1071-1079
  6. Sheng C, et al., A computational fluid dynamics based study of the combustion characteristics of coal blends in pulverised coal-fired furnace, Fuel, 83 (2004), 11, pp. 1543-1552
  7. Yin C, et al., Investigation of the flow, combustion, heat-transfer and emissions from a 609MW utility tangentially fired pulverized-coal boiler, Fuel, 81 (2002), 8, pp. 997-1006
  8. Achim D, et al., Numerical investigation of full scale coal combustion model of tangentially fired boiler with the effect of mill ducting, Heat and mass transfer, 46 (2009), 1, pp. 1-13
  9. Xiang J, et al., An Experimental Research on Performance of Nitrogen Oxide Emission from Boiler, Proceedings of the CSEE, 20 (2000), 9, pp. 80-84
  10. Yang W J, et al., Tertiary air operation optimization aiming at low NOx combustion in boiler, Journal of Zhejiang University :Engineering Science, 42 (2008), 7, pp. 1227-1230
  11. Zhou H, et al., Numerical Simulation of the NOx Emissions in a 1000MW Tangentially Fired Pulverized-Coal Boiler: Influence of the Multi-group Arrangement of the Separated over fire air, Energy & Fuels, 25 (2011), 5, pp. 2004-2012
  12. Park H Y, et al., Coupled fluid dynamics and whole plant simulation of coal combustion in a tangentially-fired boiler. Fuel, 89 (2010), 8, pp. 2001-2010
  13. Wei L H, et al., An experimental investigation on nitrogen emission properties of micropulverized during pyrolysis, Proceedings of the CSEE 26, (2006), 7, pp. 62-66
  14. Wang Y Z, et al., Experimental study on the characteristics of the nitrogen releasing from the pulverized coal combusting in the one-dimensional boiler, Journal of China Coal Society 29 (2004), 6, pp. 726-730
  15. Wang X D, T Luan, L Cheng., Experimental of effects of boiler structures and burner models on NOx emission from coal-fired boiler, Journal of China Coal Society, 32 (2007), 9, pp. 984-988
  16. Jarquin-Lopez G, et al., Analytical and experimental research for decreasing nitrogen oxides emissions, Applied Thermal Engineering, 29 (2009), 8-9, pp. 1614-1621
  17. Xiao H P, et al., Effect of Combustion Adjustment on NOx Emission and Boiler Efficiency, Proceedings of the CSEE, 31 (2011)8: 1-31
  18. Zhou J H, et al., Application of Air-staged and Low NOx Emission Combustion Technology in Plant Boiler, Proceedings of the CSEE, 23 (2010), 5, pp. 19-23
  19. LI Z Q, et al., Influence of declivitous secondary air on combustion characteristics of a downfired 300MW utility boiler, Fuel, 89 (2010), 2, pp. 410-416
  20. Zeng L Y, et al., Numerical simulation of combustion on characteristics and NOx emission in a 300 MW utility boiler with different outer second-air bane angles, Energy & Fuels 24(2010), pp. 5349-5358
  21. Fang Q Y, et al., Numerical simulations on the slagging Characteristics in a down-fired, pulverized coal boiler furnace, Fuel Processing Technology, 91 (2010), 1, pp. 88-96
  22. Belosevic S, et al., Three-dimensional modeling of utility boiler pulverized coal tangentially fired furnace, International Journal of Heat and Mass Transfer, 49 (2006), 19-20, pp. 3371-3378
  23. Choi C R, N K Chang. Numerical investigation on the flow, combustion, and NOx emission characteristics in a 500 MW tangentially fired pulverized-coal boiler, Fuel, 88 (2009), 9, pp. 1720-1731
  24. Chen T J, et al., Numerical simulation on the Optimization of Closing-to-wall Air in a 660 MW Front and Rear Wall Opposed Coal-fired Boiler, Proceedings of the CSEE 35 (2015), 20, 5265-5271
  25. Wang W S, et al., Numerical simulation on the NOx release characteristics during the combustion of power-quality anthracite in supercritical boiler, Journal of China Coal Society 37 (2012), 2, pp. 310-315
  26. Liu Y M, et al., Numerical Study on NOx Emission Characteristics of a 600 MW Opposed Firing Boiler, Journal of Chinese Society of Power Engineering, 35 (2015), 5, pp. 341-347
  27. Tao W Q., Numerical Heat Transfer, Xi'an Jiaotong University Press Xi'an, China, 2003
  28. Wang F J., Computational Fluid Dynamics Analysis, The principle and application of CFD software, Tsinghua University Press, Beijing, China, 2004
  29. Dong C, et al., Numerical modeling of the gasification based biomass co-firing in a 600MW pulverized coal boiler, Applied Energy, 87 (2010), 9, pp. 2834-2838

© 2020 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, 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