Gas-Solid Flow, Combustion Characteristics, and Gas Emissions in a 75 t/h CFB Boiler Based on the CPFD Method

HUANG Xiankun, BAI Zhang, ZHU Xiaoli, WANG Shuoshuo, MU Lin, GONG Liang

Journal of Thermal Science ›› 2025, Vol. 34 ›› Issue (1) : 323-336.

PDF(7657 KB)
PDF(7657 KB)
Journal of Thermal Science ›› 2025, Vol. 34 ›› Issue (1) : 323-336. DOI: 10.1007/s11630-025-2092-7  CSTR: 32141.14.JTS-025-2092-7

Gas-Solid Flow, Combustion Characteristics, and Gas Emissions in a 75 t/h CFB Boiler Based on the CPFD Method

Author information +
History +

Abstract

A 3D simulation using Computational Particle Fluid Dynamics (CPFD) methods was used to calculate coal combustion in a 75 t/h industrial-scale circulating fluidized bed (CFB) boiler. Combustion characteristics, gas-solid flow characteristics, and gaseous pollutant emissions of CFB boilers from combustion ignition to stable operation were systematically evaluated in this study. Results show that the temperature distribution is relatively uniform throughout the boiler. As the combustion process unfolds within the boiler, the gas composition curve strikingly portrays the inverse correlation between CO2 and O2 concentrations. As the combustion reaction progresses, it becomes evident that the concentration of CO2 progressively increases, while the concentration of O2 concurrently decreases. This inverse relationship underscores the fundamental combustion reaction, where carbon-based fuels react with oxygen to produce carbon dioxide and release energy. Furthermore, a comprehensive analysis has revealed that, from ignition to stable combustion, both nitric oxide (NO) and sulfur dioxide (SO2) emissions exhibit a declining trend. This reduction in pollutant generation is attributed to the improvement in combustion efficiency. More complete combustion leads to lower levels of unburned hydrocarbons, which are prone to NO formation. Similarly, the sulfur content in the fuel is more efficiently oxidized to sulfur trioxide (SO3) or bound in sulfates, reducing SO2 emissions. At steady state in the simulation, the SO2 mass flow rate varies significantly with the furnace height, gradually increasing from 0.07 kg·s–1 at 4 m at the bottom of the furnace to a peak of 0.078 kg·s–1 at 8 m in the center, and then decreasing to 0.06 kg·s–1 at 20 m at the top of the furnace.

Key words

circulating fluidized bed / particle flow / combustion / CPFD modeling

Cite this article

Download Citations
HUANG Xiankun , BAI Zhang , ZHU Xiaoli , WANG Shuoshuo , MU Lin , GONG Liang. Gas-Solid Flow, Combustion Characteristics, and Gas Emissions in a 75 t/h CFB Boiler Based on the CPFD Method[J]. Journal of Thermal Science, 2025, 34(1): 323-336 https://doi.org/10.1007/s11630-025-2092-7

References

[1] Gu J.R., Liu Q.W., Zhong W.Q., et al., Study on scale-up characteristics of oxy-fuel combustion in circulating fluidized bed boiler by 3D CFD simulation. Advanced Powder Technology, 2020, 31: 2136–2151.
[2] Zhang N., Lu B., Wang W., et al., 3D CFD simulation of hydrodynamics of a 150 MWe circulating fluidized bed boiler. Chemical Engineering Journal, 2010, 162: 821–828.
[3] Li J., Fan B.G., Zheng X.R., et al., Mercury emission and adsorption characteristics of fly ash in PC and CFB boilers. Frontiers in Energy, 2021, 15: 112–123.
[4] Barišić V., Peltola K., Zabetta E.C., Role of pulverized coal ash against agglomeration, fouling, and corrosion in circulating fluidized-bed boilers firing challenging biomass. Energy and Fuels, 2013, 27: 5706–5713.
[5] Wei F., Yang G.Q., Jin Y., et al., The characteristics of cluster in a high density circulating fluidized bed. Canadian Journal of Chemical Engineering, 2010, 73: 650–655.
[6] Zheng W., Zhang M., Zhang Y., et al., The effect of the secondary air injection on the gas-solid flow characteristics in the circulating fluidized bed. Chemistry Engineering Research and Design, 2019, 141: 220–228.
[7] Tu Q., Wang H., Effects of riser geometry on gas-solid flow characteristics in circulating fluidized beds. Particuology, 2020, 49: 205–217.
[8] Mu L., Chen J.B., Yin H., et al., Pyrolysis behaviors and kinetics of refining and chemicals wastewater, lignite and their blends through TGA. Bioresource Technology, 2015, 180: 22–31.
[9] Mu L., Chen J.B., Yao P., et al., Evaluation of co-pyrolysis petrochemical wastewater sludge with lignite in a thermogravimetric analyzer and a packed-bed reactor: Pyrolysis characteristics, kinetics, and products analysis. Bioresource Technology, 2016, 221: 147–156.
[10] Song G., Yang Z., Lyu Q., Investigation of gas-solid flow and temperature distribution uniformity of 350 MW supercritical CFB boiler with polygonal furnace. Powder Technology, 2019, 355: 213–225.
[11] Luo K., Wu F., Yang S., et al., High-fidelity simulation of the 3-D full-loop gas-solid flow characteristics in the circulating fluidized bed. Chemical Engineering Science, 2015, 123: 22–38.
[12] Wang X., Wu X., Lei F., et al., 3D full-loop simulation and experimental verification of gas-solid flow hydrodynamics in a dense circulating fluidized bed. Particuology, 2014, 16: 218–226.
[13] Sun Z., Zhu J., Zhang C., Numerical study on the hydrodynamics in high-density gas-solid circulating fluidized bed downer reactors. Powder Technology, 2020, 370: 184–196.
[14] Xie J., Zhong W., Shao Y., et al., Simulation of co-gasification of coal and wood in a dual fluidized bed system. Advanced Powder Technology, 2021, 32: 52–71.
[15] Loha C., Chattopadhyay H., Pradip K., Chatterjee. Assessment of drag models in simulating bubbling fluidized bed hydrodynamics. Chemical Engineering Science, 2012, 75: 400–407.
[16] Wang X., Jin B., Zhong W., Three-dimensional simulation of fluidized bed coal gasification. Chemical Engineering Process, 2009, 48: 695–705.
[17] Ocampo A., Arenas E., Chejne F., et al., An experimental study on gasification of Colombian coal in fluidised bed. Fuel, 2003, 82: 161–164. 
[18] Oevermann M., Gerber S., Behrendt F., Euler-Lagrange/ DEM simulation of wood gasification in a bubbling fluidized bed reactor. Particuology, 2007, 7: 307–316.
[19] Snider D., An incompressible three-dimensional multiphase particle-in-cell model for dense particle flows. Journal of Computational Physics, 2001, 170: 523–549.
[20] Wang Q., Yang H., Wang P., et al., Application of CPFD method in the simulation of a circulating fluidized bed with a loop seal Part II—Investigation of solids circulation. Powder Technology, 2014, 253: 822–828.
[21] Venkatesan V., Mukundarajan L., Narayanan A., Simulation of a scaled down 250 MWe CFB boiler using computational particle fluid dynamics numerical model. Chemical Product and Process Modeling, 2019, 15: 1–26. 
[22] Gao M., Zhang B., Hong F., et al., Design and application of the feed water control strategy for a 350 MW circulating fluidized bed boiler. Applied Thermal Engineering, 2017, 125: 1–8.
[23] Yan J., Lu X., Song Y., et al., A comprehensive understanding of the non-uniform characteristics and regulation mechanism of six external loops in a 600 MW supercritical CFB boiler. Energy, 2021, 222: 120032.
[24] Yang W., Handbook of fluidization and fluid-particle systems. China Part 1, 2003, 137: 1–8.
[25] Fan L., Zhu C., Principles of gas-solid flows. Cambridge University Press (CUP), 1988.
[26] Andrews M., O'Rourke P., The multiphase particle-in-cell (MP-PIC) method for dense particulate flows. International Journal of Multiphase Flow, 1996, 22: 379–402.
[27] Gu J., Zhong W., Shao Y., et al., Particle motion behaviors in dual circulation fluidized bed by Multiphase Particle-in-Cell (MP-PIC) Method. Industrial & Engineering Chemistry Research, 2018, 57: 14809–14821.
[28] Abdallah B., Huang A., Shivkumar B., et al., Numerical simulation of a commercial FCC regenerator using Multiphase Particle-in-Cell methodology (MP-PIC). Advanced Powder Technology, 2017, 28: 2947–2960.
[29] Delebarre A., Revisiting the Wen and Yu equations for minimum fluidization velocity prediction. Chemistry Engineering Research and Design, 2004, 82: 587–590.
[30] Gidaspow D., Multiphase flow and fluidization: continuum and kinetic theory description. Journal of Non-Newtonian Fluid Mechanics, 1994, 55: 207–208.
[31] Harris S., Crighton D., Solitons, solitary waves, and voidage disturbances in gas-fluidized beds. Journal of Fluid Mechanics, 1994, 266: 243–276.
[32] Zhong W., Xie J., Shao Y., et al., Three-dimensional modeling of olive cake combustion in CFB. Applied Thermal Engineering, 2015, 88: 322–333.
[33] Zheng M., Shen L., Feng X., et al., Kinetic model for parallel reactions of CaSO4 with CO in chemical-looping combustion. Industrial & Engineering Chemistry Research, 2011, 50: 5414–5427.
[34] Ostrycharczyk M., Krochmalny K., Czerep M., et al., Examinations of the sulfur emission from pulverized lignite fuel, under pyrolysis and oxy-fuel combustion condition. Fuel, 2019, 241: 579–584.
[35] Huang W., Li J., Yang H., DeNOx technology selection and optimal design of SNCR system for a 300 MWe CFB boiler. Advanced Functional Materials, 2014, 492: 7–12.
[36] Zhao J., Brereton C., Grace J., et al., Gas concentration profiles and NOx formation in circulating fluidized bed combustion. Fuel, 1997, 76: 853–860.

Funding

This work was supported by the National Natural Science Foundation of China (No. 52176030), Taishan Scholars Program of Shandong Province (No. tsqn202312115), Shandong Provincial Natural Science Foundation of China (No. ZR2022YQ58), and the Fundamental Research Funds for the Central Universities (No. 24CX06038A).

RIGHTS & PERMISSIONS

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2025
PDF(7657 KB)

54

Accesses

0

Citation

Detail

Sections
Recommended

/