Abstract
In order to reduce the original NOx emission from coal combustion, and lighten the excessive redeucer used in the De-NOx post-treatment which will lead to the corrosion of steam heat exchanger tube and economical efficiency, a new De-NOx technology combined with the De-NOx combustor and the deep air stage combustion was developed, and the technology was testified by theory, numerical simulation, pilot experiment, and industrial experiment. FR/ED (Finite Rate/Eddy Dissipation) model which considering the chemical reactions involved in the gasification process is used in the simulation, and it showed a sufficient accuracy with the experiment results. A strong reductive atmosphere including CO and CH4 was detected with a low stoichiometric ratio both by numerical simulation and experiment in a 7 MW double-cone De-NOx burner, the CO and H2 contents could be 15.457% and 0.992 for SR of 0.456, respectively, while no NOx content was detected at the burner outlet. Method Oxygen-enriched air used in the burner could intensify the reductive atmosphere, and the CO content at the center burner increased form 9.54 to 20.258%, when the oxygen content increased from 21 to 28.3%. For the 7 MW pilot boiler system, the initial NOx emission of the boiler can reach to 159 mg/m3, and the total reduction of NOx generation was more than 70.9%, when the oxygen content in secondary air was 28.3% and the proportion of staged air in tertiary air was 41.2%. Utilization of De-NOx technology in long-term industrial experiment for 40t/h steam boiler showed near no influence on the boiler operation, original NOx of less than 200 mg could be reached at the extreme condition. When the original NOx emission reduced from 697 to 300 mg/m3, the heat loss was less than 0.5%, and more than 50% of ammonia water was saved for SCR, which leading about 1 yuan per ton steam saving of the cost.
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References
Burke JM, Johnson KL (1980) An investigation of ammonium sulfate/bisulfate formation and deposition in air preheater. Radian Corporation, Nashville, Tennesses, USA
Chui EH, Gao H (2010) Estimation of NOx emissions from coal-fired utility boilers. Fuel 89:2977–2984
Duan Y, Zhang L, Mao Z et al (2017) Numerical simulation of MILD combustion on coal-water slurry. Clean Coal Technol 23(4):36–41+46 (in Chinese)
Fan W, Li Y, Guo Q et al (2017) Coal-nitrogen release and NOx evolution in the oxidant-staged combustion of coal. Energy. https://doi.org/10.1016/j.energy.2017.02.130
Jiang S, Wang Y, Zhou J et al (2014) Numerical simulation on middle volatile coal combustion in reversed injection burner. J China Coal Soc 39(6):1147–1153 (in Chinese)
Li P (2017) Principle and application of air staged combustion technology. Boiler Technol 48(4):45–50 (in Chinese)
Li H, Zhou J, Liu G et al (2016) Experiment study on NOx emission features during staged-air combustion process of pulverized coal. Coal Sci Technol 44(12):194–201 (in Chinese)
Liu W, Ouyang Z, Cao X, Na Y (2019) The influence of air-stage method on flameless combustion of coal gasification fly ash with coal self-preheating technology. Fuel 235:1368–1376
Man CK, Gibbins JR, Witkamp JG, Zhang J (2005) Coal characterisation for NOx prediction in air-staged combustion of pulverised coals. Fuel 84:2190–2195
Mo R, Wang N, Cheng X (2018) Numerical analysis of coal water mixture combustion in double cone reversed injection burner. Clean Coal Technol 24(2):83–89 (in Chinese)
Ouyang Z, Liu W, Man C, Zhu J, Liu J (2018) Experimental study on combustion, flame and NOx emission of pulverized coal preheated by a preheating burner. Fuel Process Technol 179:197–202
Scheffknecht G, Al-Makhadmeh L, Schnell U (2011) Oxy-fuel coal combustion—a review of the current state-of-the-art. Int J Greenh Gas Control 5:16–35
Shaddix CR, Molina A (2011) Fundamental investigation of NOx formation during oxy-fuel combustion of pulverized coal. Proc Combust Inst 33:1723–1730
Shao W, Wang W, Pan W (2017) Mechanism of NOx emission reduction by air-staged combustion and the influencing factors. Power Equip 31(1):23–25 (in Chinese)
Stanger R, Wall T, Sporl R (2015) Oxy-fuel combustion for CO2 capture in power plants. Int J Greenh Gas Control 40:55–125
Sun B, Wang D, Duan E et al (2013) Investigation on NOx formation characteristics under air-staged combustion. J Chin Soc Power Eng 33(4):261–266 (in Chinese)
Tsumuraa T, Okazaki H, Dernjatin P, Savolainen K (2003) Reducing the minimum load and NOx emissions for lignite-fired boiler by applying a stable-flame concept. Appl Energy 74:415–424
Watanabe H, Hichiro Y, Okazaki K (2011) NOx formation and reduction mechanisms in staged O2/CO2 combustion. Combust Flame 158(7):1255–1263
Wilburn RT (2004) Wright TL (2004) SCR ammonia slip distribution in coal plant effluents and dependence upon SO3. Power Plant Chem 6(5):295–304
Ye D, Qu R, Song H et al (2016) New insights into the various decomposition and reactivity behaviors of NH4HSO4 with NO on V2O5/TiO2 catalyst surfaces. Chem Eng J 283:846–854
Zhang Y, Zhang Y, Yang T et al (2017) Numerical simulation on combustion of lignite semi-char in cyclone furnace. Therm Power Gener 46(2):42–48+54 (in Chinese)
Zhou X (2016) Application of low NOx retrofit technology in small and medium pulverized coal fired boiler. Ind Furn 38(3):43–48 (in Chinese)
Zhou H, Yang Y, Dong K, Liu HZ, Shen YL, Cen KF (2014) Influence of the gas particle flow characteristics of a low-NOx swirl burner on the formation of high temperature corrosion. Fuel 134:595–602
Zhou CY, Wang YQ, Jin QY, Zhou YG (2018) Mechanisms analysis on the pulverized coal combustion flame stability and NOx emission in a swirl burner with deep air staging. J Energy Inst 1–13
Acknowledgements
This work was supported by the China Coal Research Institute Innovation Fund project (No. 2017CX02), and the China Coal Science and Technology Group Innovation Fund Project (No. 2018MS003).
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Cheng, X., Wang, N., Zhang, X., Wang, Y., Chen, L. (2022). The Mechanisms and Applications of NOx Reduction by Low-NOx Burner Coupling Deep Air-Staging Technology in Pulverized Coal. In: Lyu, J., Li, S. (eds) Clean Coal and Sustainable Energy. ISCC 2019. Environmental Science and Engineering. Springer, Singapore. https://doi.org/10.1007/978-981-16-1657-0_61
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DOI: https://doi.org/10.1007/978-981-16-1657-0_61
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