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2024 , Vol. 33 >Issue 5: 1935 - 1945

DOI: https://doi.org/10.1007/s11630-024-2001-5

Flame Morphology and Characteristic of Co-Firing Ammonia with Pulverized Coal on a Flat Flame Burner

  • WANG Shengye ,
  • CUI Mingshuang ,
  • LIU Pengzhong ,
  • DI Yi ,
  • NIU Fang
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  • 1. China Coal Research Institute, Beijing 100013, China
    2. Beijing Tiandi Rongchuang Technology Co. Ltd., Beijing 100013, China
    3. National Energy Technology & Equipment Laboratory of Coal Utilization and Emission Control, Beijing 100013, China

网络出版日期: 2024-09-09

基金资助

This work was supported by the Technology Innovation and Entrepreneurship Fund Key Project of Tiandi Technology Co., Ltd. (2021-TD-ZD005).

版权

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2024
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Flame Morphology and Characteristic of Co-Firing Ammonia with Pulverized Coal on a Flat Flame Burner

  • WANG Shengye ,
  • CUI Mingshuang ,
  • LIU Pengzhong ,
  • DI Yi ,
  • NIU Fang
Expand
  • 1. China Coal Research Institute, Beijing 100013, China
    2. Beijing Tiandi Rongchuang Technology Co. Ltd., Beijing 100013, China
    3. National Energy Technology & Equipment Laboratory of Coal Utilization and Emission Control, Beijing 100013, China

Online published: 2024-09-09

Supported by

This work was supported by the Technology Innovation and Entrepreneurship Fund Key Project of Tiandi Technology Co., Ltd. (2021-TD-ZD005).

Copyright

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2024
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摘要

氨气作为一种新型绿色无碳燃料，与煤掺烧可以有效减少二氧化碳排放，但对于氨气与煤掺烧的火焰形态和特性的研究还不够充分。在本研究中，我们在平焰燃烧器上研究了不同氧气摩尔分数和掺氨比下氨煤掺烧火焰。首先，我们发现随着氨气的加入，氨煤混燃火焰产生了分层现象，在火焰根部存在透明火焰区域被认定为氨气燃烧区。由于氨煤混燃火焰中无法直接观测到煤粉颗粒的着火情况，因此使用Matlab软件分析不同掺氨比和氧气摩尔分数下的火焰图像。分析结果表明，与纯煤燃烧相比，氨气的加入使点火延迟时间提前4.21 ms-5.94 ms。随着掺氨比的增加，点火延迟时间先减少后增加。同时，氧气摩尔分数的增加也使点火延迟时间提前，煤粉的燃尽时间和火焰扩展角度分别随着氨气比例的增加呈线性减少和增加。氨气的加入促进了煤颗粒挥发物的释放，在高掺氨比的条件下，氧气的消耗也阻碍了煤颗粒的表面反应。最后，对氨煤混燃火焰流场中气体组分进行测定，发现燃烧过程中生成的富含水的环境加剧了煤粉的气化反应，导致CO浓度升高。同时，煤颗粒气化过程中生成的含氮物质和焦炭与NOx发生还原反应，减少了NOx的排放。

关键词： co-firing ammonia with coal; flame characteristic; gas component; ignition delay time; burn-off time; flame divergence angle; flat flame burner; flame morphology

本文引用格式

WANG Shengye , CUI Mingshuang , LIU Pengzhong , DI Yi , NIU Fang . Flame Morphology and Characteristic of Co-Firing Ammonia with Pulverized Coal on a Flat Flame Burner[J]. 热科学学报, 2024 , 33(5) : 1935 -1945 . DOI: 10.1007/s11630-024-2001-5

Abstract

Ammonia as a new green carbon free fuel co-combustion with coal can effectively reduce CO2 emission, but the research of flame morphology and characteristics of ammonia-coal co-combustion are not enough. In this work, we studied the co-combustion flame of NH3 and pulverized coal on flat flame burner under different oxygen mole fraction (Xi,O2) and NH3 co-firing energy ratios (ENH3). We initially observed that the introduction of ammonia resulted in stratification within the ammonia-coal co-combustion flame, featuring a transparent flame at the root identified as the ammonia combustion zone. Due to challenges in visually observing the ignition of coal particles in the ammonia-coal co-combustion flame, we utilized Matlab software to analyze flame images across varying ENH3 and Xi,O2. The analysis indicates that, compared to pure coal combustion, the addition of ammonia advances the ignition delay time by 4.21 ms to 5.94 ms. As ENH3 increases, the ignition delay time initially decreases and then increases. Simultaneously, an increase in Xi,O2 results in an earlier ignition delay time. The burn-off time and the flame divergence angle of pulverized coal demonstrated linear decreases and increases, respectively, with the growing ammonia ratio. The addition of ammonia facilitates the release of volatile matter from coal particles. However, in high-ammonia environments, oxygen consumption also impedes the surface reaction of coal particles. Finally, measurements of gas composition in the ammonia-coal flame flow field unveiled that the generated water-rich atmosphere intensified coal particle gasification, resulting in an elevated concentration of CO. Simultaneously, nitrogen-containing substances and coke produced during coal particle gasification underwent reduction reactions with NOx, leading to reduced NOx emissions.

Key words： co-firing ammonia with coal; flame characteristic; gas component; ignition delay time; burn-off time; flame divergence angle; flat flame burner; flame morphology

参考文献

[1] Kobayashi H., Hayakawa A., Somarathne K.D.K.A, et al., Science and technology of ammonia combustion. Proceedings of the Combustion Institute, 2019, 37(1): 109–133.
[2] Valera-Medina A., Xiao H., Owen-Jones M., et al., Ammonia for power. Progress in Energy and Combustion Science, 2018, 69: 63–102.
[3] Valera-Medina A., Marsh R., Runyon J., et al. Ammonia-methane combustion in tangential swirl burners for gas turbine power generation. Applied Energy, 2017, 185: 1362–1371.
[4] Mei B., Zhang J., Shi X., et al., Enhancement of ammonia combustion with partial fuel cracking strategy: Laminar flame propagation and kinetic modeling investigation of NH3/H2/N2/air mixtures up to 10 atm. Combustion and Flame, 2021, 231: 111472.
[5] Li J., Huang H., Kobayashi N., et al., Study on using hydrogen and ammonia as fuels: Combustion characteristics and NOx formation. International Journal of Energy Research, 2014, 38(9): 1214–1223.
[6] Hayakawa A., Goto T., Mimoto R., et al., Laminar burning velocity and Markstein length of ammonia/air premixed flames at various pressures. Fuel, 2015, 159: 98–106.
[7] Chiuta S., Everson R.C., Neomagus H.W.J.P., et al., Reactor technology options for distributed hydrogen generation via ammonia decomposition: A review. International Journal of Hydrogen Energy, 2013, 38(35): 14968–14991. 
[8] Bartels J.R., A feasibility study of implementing an Ammonia Economy. Iowa State University, 2008.
[9] Valera-Medina A., Xiao H., Owen-Jones M., et al., Ammonia for power. Progress in Energy and Combustion Science, 2018, 69: 63–102.
[10] Kurata O., Iki N., Matsunuma T., et al., Performances and emission characteristics of NH3-air and NH3-CH4-air combustion gas-turbine power generations. Proceedings of the Combustion Institute, 2017, 36(3): 3351–3359.
[11] Mei B., Zhang X., Ma S., et al., Experimental and kinetic modeling investigation on the laminar flame propagation of ammonia under oxygen enrichment and elevated pressure conditions. Combustion and Flame, 2019, 210: 236–246.
[12] Cai T., Zhao D., Temperature dependence of laminar burning velocity in ammonia/dimethyl ether-air premixed flames. Journal of Thermal Science, 2022, 31: 189–197.
[13] Xia Y., Hadi K., Hashimoto G., et al., Effect of ammonia/oxygen/nitrogen equivalence ratio on spherical turbulent flame propagation of pulverized coal/ammonia co-combustion. Proceedings of the Combustion Institute, 2021, 38(3): 4043–4052.
[14] Hadi K., Ichimura R., Hashimoto G., et al., Effect of fuel ratio of coal on the turbulent flame speed of ammonia/coal particle cloud co-combustion at atmospheric pressure. Proceedings of the Combustion Institute, 2021, 38(3): 4131–4139.
[15] Tamura M., Gotou T., Ishii H., et al., Experimental investigation of ammonia combustion in a bench scale 1.2 MW-thermal pulverised coal firing furnace. Applied Energy, 2020, 277: 115580.
[16] Zhang J., Ito T., Ishii H., et al., Numerical investigation on ammonia co-firing in a pulverized coal combustion facility: Effect of ammonia co-firing ratio. Fuel, 2020, 267: 117166. 
[17] Wang F., Chen Q., Waneng Tongling power generation company: Successful ignition of the first 8.3 megawatt pure ammonia combustor in a 300,000-Kilowatt thermal power unit in China. China Electric Power Enterprise Management, 2022, 12: 96. (in Chinese)
[18] Niu T., Zhang W.Z., Liu X., et al., Industrial-scale experimental study on ammonia-coal co-combustion in coal-fired boilers. Clean Coal Technology, 2022, 28(03): 193–200. DOI: 10.13226/j.issn.1006-6772.cc22022401.
[19] Lee H., Lee M.J., Recent advances in ammonia combustion technology in thermal power generation system for carbon emission reduction. Energies, 2021, 14(18): 5604.
[20] Butler M.O., Thompson A., House introduces CLEAN future act - a comprehensive bill to achieve a net zero greenhouse gas economy by 2050. (Accessed on Mar 15, 2021). https://www.jdsupra.com/legalnews/house-introduces-clean-future-act-a-5817139
[21] Chen P., Jiang B.Y., Hua C.H., et al., Experimental study on the effect of oxygen concentration on the heterogeneous reduction of NH3/Char/NO in the high temperature reduction zone during ammonia-coal co-combustion. Journal of Chinese Coal Society, 2023, 48(10): 3912–3919.
[22] Murai R., Omori R., Kano R., et al., The radiative characteristics of NH3/N2/O2 non-premixed flame on a 10 kW test furnace. Energy Procedia, 2017, 120: 325–332.
[23] Gao Q., Experimental study on the effect of oxygen concentration on the heterogeneous reduction of NH3/Char/NO in the high temperature reduction zone during ammonia-coal co-combustion. Tsinghua University, 2019. (in Chinese)
[24] Katzer C., Babul K., Klatt M., et al., Quantitative and qualitative relationship between swirl burner operatingconditions and pulverized coal flame length. Fuel Processing Technology, 2017, 156: 138–155.
[25] Hashimoto N., Shirai H., Numerical simulation of sub-bituminous coal and bituminous coal mixed combustion employing tabulated-devolatilization-process model. Energy, 2014, 71: 399–413.
[26] Shaddix C.R., Molina A., Particle imaging of ignition and devolatilization of pulverized coal during oxy-fuel combustion. Proceedings of the Combustion Institute, 2009, 32(2): 2091–2098.
[27] Riaza J., Khatami R., Levendis Y.A., et al., Single particle ignition and combustion of anthracite, semi-anthracite and bituminous coals in air and simulated oxy-fuel conditions. Combustion and Flame, 2014, 161(4): 1096–1108.
[28] Lee H., Choi S., An observation of combustion behavior of a single coal particle entrained into hot gas flow. Combustion and Flame, 2015, 162(6): 2610–2620.
[29] Zhu W.K., Qi H.L., Yang Y.Q., et al., Ignition and combustion characteristics of pulverized coal jet flame based on OH-PLIF measurement techniques. Journal of Combustion Science and Technology, 2019, 25(02): 175–181.
[30] Khatami R., Stivers C., Joshi K., et al., Combustion behavior of single particles from three different coal ranks and from sugar cane bagasse in O2/N2 and O2/CO2 atmospheres. Combustion and Flame, 2012, 159(3): 1253–1271.
[31] Yuan Y., Li S., Li G., et al., The transition of heterogeneous-homogeneous ignitions of dispersed coal particle streams. Combustion and Flame, 2014, 161(9): 2458–2468.
[32] Liu Y., Geier M., Molina A., et al., Pulverized coal stream ignition delay under conventional and oxy-fuel combustion conditions. International Journal of Greenhouse Gas Control, 2011, 5: S36–S46.
[33] Ma P., Huang Q., Wu Z., et al., Optical diagnostics on coal ignition and gas-phase combustion in co-firing ammonia with pulverized coal on a two-stage flat flame burner. Proceedings of the Combustion Institute, 2023, 39(3): 3457–3466.
[34] Wu Z.Q., Huang Q., Ma P., et al., Ignition characteristics of single coal particle during ammonia-coal co-combustion process. Clean Coal Technology, 2023, 29(10): 108–115. DOI: 10.13226/j.issn.1006-6772.F23032801.
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