Particle residence time distribution and axial dispersion coefficient in a pressurized circulating fluidized bed by using multiphase particle-in-cell simulation

doi:10.1016/j.cjche.2024.01.020

摘要/Abstract

摘要： The particle residence time distribution (RTD) and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed (PCFB). In this study, the effects of pressure (0.1-0.6 MPa), fluidizing gas velocity (2-7 m·s^-1), and solid circulation rate (10-90 kg·m^-2·s^-1) on particle RTD and axial dispersion coefficient in a PCFB are numerically investigated based on the multiphase particle-in-cell (MP-PIC) method. The details of the gas-solid flow behaviors of PCFB are revealed. Based on the gas-solid flow pattern, the particles tend to move more orderly under elevated pressures. With an increase in either fluidizing gas velocity or solid circulation rate, the mean residence time of particles decreases while the axial dispersion coefficient increases. With an increase in pressure, the core-annulus flow is strengthened, which leads to a wider shape of the particle RTD curve and a larger mean particle residence time. The back-mixing of particles increases with increasing pressure, resulting in an increase in the axial dispersion coefficient.

关键词: Pressurized circulating fluidized bed, MP-PIC method, Residence time distribution, Axial dispersion coefficient

Abstract: The particle residence time distribution (RTD) and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed (PCFB). In this study, the effects of pressure (0.1-0.6 MPa), fluidizing gas velocity (2-7 m·s^-1), and solid circulation rate (10-90 kg·m^-2·s^-1) on particle RTD and axial dispersion coefficient in a PCFB are numerically investigated based on the multiphase particle-in-cell (MP-PIC) method. The details of the gas-solid flow behaviors of PCFB are revealed. Based on the gas-solid flow pattern, the particles tend to move more orderly under elevated pressures. With an increase in either fluidizing gas velocity or solid circulation rate, the mean residence time of particles decreases while the axial dispersion coefficient increases. With an increase in pressure, the core-annulus flow is strengthened, which leads to a wider shape of the particle RTD curve and a larger mean particle residence time. The back-mixing of particles increases with increasing pressure, resulting in an increase in the axial dispersion coefficient.

Key words: Pressurized circulating fluidized bed, MP-PIC method, Residence time distribution, Axial dispersion coefficient

Jinnan Guo, Daoyin Liu, Jiliang Ma, Cai Liang, Xiaoping Chen. Particle residence time distribution and axial dispersion coefficient in a pressurized circulating fluidized bed by using multiphase particle-in-cell simulation[J]. 中国化学工程学报, 2024, 69(5): 167-176.

参考文献

[1] J. Hong, G. Chaudhry, J.G. Brisson, R. Field, M. Gazzino, A.F. Ghoniem, Analysis of oxy-fuel combustion power cycle utilizing a pressurized coal combustor, Energy 34(9)(2009)1332-1340.
[2] E.S. Rubin, H. Mantripragada, A. Marks, P. Versteeg, J. Kitchin, The outlook for improved carbon capture technology, Prog. Energy Combust. Sci. 38(5)(2012)630-671.
[3] S. Yadav, S.S. Mondal, A review on the progress and prospects of oxy-fuel carbon capture and sequestration (CCS) technology, Fuel 308(2022)122057.
[4] Y. Shi, W.Q. Zhong, Y.J. Shao, X.J. Liu, Energy efficiency analysis of pressurized oxy-coal combustion system utilizing circulating fluidized bed, Appl. Therm. Eng. 150(2019)1104-1115.
[5] Y.Q. Duan, L.B. Duan, J. Wang, E.J. Anthony, Observation of simultaneously low CO, NO_x and SO₂ emission during oxy-coal combustion in a pressurized fluidized bed, Fuel 242(2019)374-381.
[6] L. Li, L.B. Duan, Z.H. Yang, C.S. Zhao, Pressurized oxy-fuel combustion characteristics of single coal particle in a visualized fluidized bed combustor, Combust. Flame 211(2020)218-228.
[7] Q.W. Liu, W.Q. Zhong, A.B. Yu, C.H. Wang, Co-firing of coal and biomass under pressurized oxy-fuel combustion mode in a 10 kWth fluidized bed:Nitrogen and sulfur pollutants, Chem. Eng. J. 450(2022)138401.
[8] L. Pang, Y.J. Shao, W.Q. Zhong, H. Liu, Experimental investigation on the coal combustion in a pressurized fluidized bed, Energy 165(2018)1119-1128.
[9] D. Stokie, P. Verma, B.M. Kumfer, G. Yablonsky, A.K. Suresh, R.L. Axelbaum, Pilot-scale testing of direct contact cooler for the removal of SOx and NO_x from the flue gas of pressurized oxy-coal combustion, Chem. Eng. J. 414(2021)128757.
[10] M. Vodička, N.E. Haugen, A. Gruber, J. Hrdlička, NO_x formation in oxy-fuel combustion of lignite in a bubbling fluidized bed-Modelling and experimental verification, Int. J. Greenh. Gas Contr. 76(2018)208-214.
[11] D.Y. Liu, J.L. Song, J.L. Ma, X.P. Chen, B. van Wachem, Gas flow distribution and solid dynamics in a thin rectangular pressurized fluidized bed using CFD-DEM simulation, Powder Technol. 373(2020)369-383.
[12] I. Sidorenko, M.J. Rhodes, Influence of pressure on fluidization properties, Powder Technol. 141(1-2)(2004)137-154.
[13] X.L. Zhu, Y.B. Liu, Y.H. Li, H.G. Wang, Z.B. Wang, Bubble behaviors of Geldart B particle in a pseudo two-dimensional pressurized fluidized bed, Particuology 79(2023)121-132.
[14] P.F. Dong, Q.Y. Tu, H.G. Wang, Z.P. Zhu, Effects of pressure on flow characteristics in a pressurized circulating fluidized bed, Particuology 59(2021)16-23.
[15] M. Richtberg, R. Richter, K.E. Wirth, Characterization of the flow patterns in a pressurized circulating fluidized bed, Powder Technol. 155(2)(2005)145-152.
[16] W. Nie, R.T. Feng, J.G. Li, Z.H. Hao, H.J. Zhan, Z.H. Cheng, Y.T. Fang, Gas-solid flow behaviors in a pressurized multi-stage circulating fluidized bed with Geldart group B particles, Int. J. Chem. React. Eng. 17(12)(2019)20190087.
[17] R.T. Feng, J.G. Li, L.B. Dong, Z.H. Hao, Z.R. Ba, H.J. Zhan, Y.T. Fang, Gas-solid flow behaviors in a multi-stage circulating fluidized bed under elevated pressure, Chem. Eng. Sci. 196(2019)1-13.
[18] M. Tsukada, D. Nakanishi, M. Horio, The effect of pressure on the phase transition from bubbling to turbulent fluidization, Int. J. Multiph. Flow 19(1)(1993)27-34.
[19] X.L. Zhu, P.F. Dong, Q.Y. Tu, Z.P. Zhu, W.Q. Yang, H.G. Wang, Investigation of gas-solids flow characteristics in a pressurised circulating fluidised bed by experiment and simulation, Powder Technol. 366(2020)420-433.
[20] X.L. Zhu, P.F. Dong, Q.Y. Tu, Z.P. Zhu, W.Q. Yang, H.G. Wang, Investigation of gas-solid flow characteristics in the cyclone dipleg of a pressurised circulating fluidised bed by ECT measurement and CPFD simulation, Meas. Sci. Technol. 30(5)(2019)054002.
[21] J.D. Hu, D.Y. Liu, H. Li, C. Liang, X.P. Chen, Experimental study of the solid circulation rate in a pressurized circulating fluidized bed, Particuology 56(2021)207-214.
[22] D.Y. Liu, J.D. Hu, J.L. Song, C. Liang, C.L. Xu, X.P. Chen, Effect of elevated pressure on gas-solid flow characteristics in a circulating fluidized bed, Powder Technol. 366(2020)470-476.
[23] Y.J. Gao, F.J. Muzzio, M.G. Ierapetritou, A review of the residence time distribution (RTD) applications in solid unit operations, Powder Technol. 228(2012)416-423.
[24] S. Mahmoudi, J.P.K. Seville, J. Baeyens, The residence time distribution and mixing of the gas phase in the riser of a circulating fluidized bed, Powder Technol. 203(2)(2010)322-330.
[25] J.W. Zhang, G.W. Xu, Scale-up of bubbling fluidized beds with continuous particle flow based on particle-residence-time distribution, Particuology 19(2015)155-163.
[26] B. Lan, J. Xu, P. Zhao, Z. Zou, J.W. Wang, Q.S. Zhu, Scale-up effect of residence time distribution of polydisperse particles in continuously operated multiple-chamber fluidized beds, Chem. Eng. Sci. 244(2021)116809.
[27] M.J. Rhodes, S. Zhou, T. Hirama, H. Cheng, Effects of operating conditions on longitudinal solids mixing in a circulating fluidized bed riser, AIChE. J. 37(10)(1991)1450-1458.
[28] C.W. Chan, J. Seville, Z.F. Yang, J. Baeyens, Particle motion in the CFB riser with special emphasis on PEPT-imaging of the bottom section, Powder Technol. 196(3)(2009)318-325.
[29] M. Van de Velden, J. Baeyens, J.P.K. Seville, X. Fan, The solids flow in the riser of a circulating fluidised bed (CFB) viewed by positron emission particle tracking (PEPT), Powder Technol. 183(2)(2008)290-296.
[30] A.T. Harris, J.F. Davidson, R.B. Thorpe, A novel method for measuring the residence time distribution in short time scale particulate systems, Chem. Eng. J. 89(1-3)(2002)127-142.
[31] A.T. Harris, J.F. Davidson, R.B. Thorpe, Particle residence time distributions in circulating fluidised beds, Chem. Eng. Sci. 58(11)(2003)2181-2202.
[32] S.S. Chapadgaonkar, Y.P. Setty, Residence time distribution of solids in a fluidised bed. Indian J. Chem. Technol. 6(1999)100-106.
[33] K. Luo, F. Wu, S.L. Yang, M.M. Fang, J.R. Fan, High-fidelity simulation of the 3-D full-loop gas-solid flow characteristics in the circulating fluidized bed, Chem. Eng. Sci. 123(2015)22-38.
[34] L.N. Hua, J.W. Wang, Residence time distribution of particles in circulating fluidized bed risers, Chem. Eng. Sci. 186(2018)168-190.
[35] X.G. Shi, X.Y. Lan, F. Liu, Y.H. Zhang, J.S. Gao, Effect of particle size distribution on hydrodynamics and solids back-mixing in CFB risers using CPFD simulation, Powder Technol. 266(2014)135-143.
[36] H. Yoo, H. Moon, S. Choi, Y.K. Park, H.H. Cho, Effect of the jet direction of gas nozzle on the residence time distribution of solids in circulating fluidized bed risers, J. Taiwan Inst. Chem. Eng. 71(2017)235-243.
[37] Q. Zhou, J.W. Wang, J.H. Li, Three-dimensional simulation of dense suspension upflow regime in high-density CFB risers with EMMS-based two-fluid model, Chem. Eng. Sci. 107(2014)206-217.
[38] D.M. Snider, S.M. Clark, P.J. O'Rourke, Eulerian-Lagrangian method for three-dimensional thermal reacting flow with application to coal gasifiers, Chem. Eng. Sci. 66(6)(2011)1285-1295.
[39] J.R. Gu, Y.J. Shao, W.Q. Zhong, 3D simulation on pressurized oxy-fuel combustion of coal in fluidized bed, Adv. Powder Technol. 31(7)(2020)2792-2805.
[40] S.L. Yang, F.H. Fan, Y.G. Wei, J.H. Hu, H. Wang, S.H. Wu, Three-dimensional MP-PIC simulation of the steam gasification of biomass in a spouted bed gasifier, Energy Convers. Manag. 210(2020)112689.
[41] A. Klimanek, J. Bigda, CFD modelling of CO₂ enhanced gasification of coal in a pressurized circulating fluidized bed reactor, Energy 160(2018)710-719.
[42] X.H. Liu, S. Wang, S.L. Yang, H. Wang, Investigation of cluster property in the riser of circulating fluidized bed with a wide particle size distribution, Powder Technol. 390(2021)273-291.
[43] S.L. Yang, S. Wang, H. Wang, Impact of polydispersity on the flow dynamics in the riser of a circulating fluidized bed, Powder Technol. 381(2021)489-502.
[44] C. Li, Q. Eri, Comparison between two Eulerian-Lagrangian methods:CFD-DEM and MPPIC on the biomass gasification in a fluidized bed, Biomass Convers. Bior. 13(2023)3819-3836.
[45] A. Vaidheeswaran, A. Gel, M.A. Clarke, W.A. Rogers, Assessment of model parameters in MFiX particle-in-cell approach, Adv. Powder Technol. 32(8)(2021)2962-2977.
[46] M.J. Andrews, P.J. O'Rourke, The multiphase particle-in-cell (MP-PIC) method for dense particulate flows, Int. J. Multiph. Flow 22(2)(1996)379-402.
[47] D.M. Snider, An incompressible three-dimensional multiphase particle-in-cell model for dense particle flows, J. Comput. Phys. 170(2)(2001)523-549.
[48] D. Gidaspow, J. Jung, R.K. Singh, Hydrodynamics of fluidization using kinetic theory:An emerging paradigm, Powder Technol. 148(2-3)(2004)123-141.
[49] S.E. Harris, D.G. Crighton, Solitons, solitary waves, and voidage disturbances in gas-fluidized beds, J. Fluid Mech. 266(1994)243-276.
[50] F.M. Auzerais, R. Jackson, W.B. Russel, The resolution of shocks and the effects of compressible sediments in transient settling, J. Fluid Mech. 195(1988)437-462.
[51] Y. Wu, D.Y. Liu, J.D. Hu, J.L. Ma, X.P. Chen, Comparative study of two fluid model and dense discrete phase model for simulations of gas-solid hydrodynamics in circulating fluidized beds, Particuology 55(2021)108-117.
[52] A. Nikolopoulos, A. Stroh, M. Zeneli, F. Alobaid, N. Nikolopoulos, J. Strohle, S. Karellas, B. Epple, P. Grammelis, Numerical investigation and comparison of coarse grain CFD-DEM and TFM in the case of a 1 MWth fluidized bed carbonator simulation, Chem. Eng. Sci. 163(2017)189-205.
[53] P. Ostermeier, S. DeYoung, A. Vandersickel, S. Gleis, H. Spliethoff, Comprehensive investigation and comparison of TFM, DenseDPM and CFD-DEM for dense fluidized beds, Chem. Eng. Sci. 196(2019)291-309.
[54] J.L. Song, D.Y. Liu, J.L. Ma, X.P. Chen, Effect of elevated pressure on bubble properties in a two-dimensional gas-solid fluidized bed, Chem. Eng. Res. Des. 138(2018)21-31.
[55] D.Y. Liu, X.P. Chen, Lateral solids dispersion coefficient in large-scale fluidized beds, Combust. Flame 157(11)(2010)2116-2124.
[56] D. Bai, E. Shibuya, Y. Masuda, K. Nishio, N. Nakagawa, K. Kato, Distinction between upward and downward flows in circulating fluidized beds, Powder Technol. 84(1)(1995)75-81.
[57] J.R. Grace, High-velocity fluidized bed reactors, Chem. Eng. Sci. 45(8)(1990)1953-1966.
[58] S. Mahmoudi, C.W. Chan, A. Brems, J. Seville, J. Baeyens, Solids flow diagram of a CFB riser using Geldart B-type powders, Particuology 10(1)(2012)51-61.