SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2022, Vol. 46 ›› Issue (6): 40-52.DOI: 10.1016/j.cjche.2021.06.005

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Particle collision behavior and heat transfer performance in a Na2SO4 circulating fluidized bed evaporator

Feng Jiang1,2, Di Xu1, Ruijia Li1, Guopeng Qi3, Xiulun Li1   

  1. 1 School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China;
    2 Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology, Tianjin University, Tianjin 300350, China;
    3 School of Biological and Environmental Engineering, Tianjin Vocational Institute, Tianjin 300410, China
  • Received:2021-03-06 Revised:2021-06-10 Online:2022-07-20 Published:2022-06-28
  • Contact: Feng Jiang,E-mail:jiangfeng@tju.edu.cn
  • Supported by:
    This work is supported by the open foundation of State Key Laboratory of Chemical Engineering (SKL-ChE-18B03) and by the Municipal Science and Technology Commission of Tianjin, China under Contract No. 2009ZCKFGX01900.

Particle collision behavior and heat transfer performance in a Na2SO4 circulating fluidized bed evaporator

Feng Jiang1,2, Di Xu1, Ruijia Li1, Guopeng Qi3, Xiulun Li1   

  1. 1 School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China;
    2 Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology, Tianjin University, Tianjin 300350, China;
    3 School of Biological and Environmental Engineering, Tianjin Vocational Institute, Tianjin 300410, China
  • 通讯作者: Feng Jiang,E-mail:jiangfeng@tju.edu.cn
  • 基金资助:
    This work is supported by the open foundation of State Key Laboratory of Chemical Engineering (SKL-ChE-18B03) and by the Municipal Science and Technology Commission of Tianjin, China under Contract No. 2009ZCKFGX01900.

Abstract: The particle collision behavior and heat transfer performance are investigated to reveal the heat transfer enhancement and fouling prevention mechanism in a Na2SO4 circulating fluidized bed evaporator. The particle collision signals are analyzed with standard deviation by varying the amount of added particles ε (1%–3%), circulation flow velocity u (0.37–1.78 m·s-1), and heat flux q (7.29–12.14 kW·m-2). The results show that the enhancement factor reach up to 14.6% by adding polytetrafluoroethylene particles at ε = 3%, u = 1.78 m·s-1, and q = 7.29 kW·m-2. Both the standard deviation of the particle collision signal and enhancement factor increase with the increase in the amount of added particles. The standard deviation increases with the increase in circulation flow velocity; however, the enhancement factor initially decreases and then increases. The standard deviation slightly decreases with the increase in heat flux at low circulation flow velocity, but initially increases and then decreases at high circulation flow velocity. The enhancement factor decreases with the increase in heat flux. The enhancement factor in Na2SO4 solution is superior to that in water at high amount of added particles. The empirical correlation for heat transfer is established, and the model results agree well with the experimental data.

Key words: Heat transfer enhancement, Particle collision behavior, Circulating fluidized bed, Evaporation, Na2SO4, Standard deviation

摘要: The particle collision behavior and heat transfer performance are investigated to reveal the heat transfer enhancement and fouling prevention mechanism in a Na2SO4 circulating fluidized bed evaporator. The particle collision signals are analyzed with standard deviation by varying the amount of added particles ε (1%–3%), circulation flow velocity u (0.37–1.78 m·s-1), and heat flux q (7.29–12.14 kW·m-2). The results show that the enhancement factor reach up to 14.6% by adding polytetrafluoroethylene particles at ε = 3%, u = 1.78 m·s-1, and q = 7.29 kW·m-2. Both the standard deviation of the particle collision signal and enhancement factor increase with the increase in the amount of added particles. The standard deviation increases with the increase in circulation flow velocity; however, the enhancement factor initially decreases and then increases. The standard deviation slightly decreases with the increase in heat flux at low circulation flow velocity, but initially increases and then decreases at high circulation flow velocity. The enhancement factor decreases with the increase in heat flux. The enhancement factor in Na2SO4 solution is superior to that in water at high amount of added particles. The empirical correlation for heat transfer is established, and the model results agree well with the experimental data.

关键词: Heat transfer enhancement, Particle collision behavior, Circulating fluidized bed, Evaporation, Na2SO4, Standard deviation