SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2023, Vol. 56 ›› Issue (4): 242-254.DOI: 10.1016/j.cjche.2022.07.024

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Cracking and buoyancy effect on hydrocarbon endothermic and heat transfer characteristics in rectangular mini-channel

Chengang Yang, Huaizhi Han, Quan Zhu, Xiangyuan Li   

  1. School of Chemical Engineering, Sichuan University, Chengdu 610065, China;Engineering Research Center of Combustion and Cooling for Aerospace Power, Ministry of Education, Sichuan University, Chengdu 610065, China
  • Received:2022-04-13 Revised:2022-07-20 Online:2023-06-13 Published:2023-04-28
  • Contact: Huaizhi Han,E-mail:hanhz@scu.edu.cn
  • Supported by:
    This work was supported by the Scientific Research Start-up Funds for Introducing Talent at Sichuan University (20822041C4013).

Cracking and buoyancy effect on hydrocarbon endothermic and heat transfer characteristics in rectangular mini-channel

Chengang Yang, Huaizhi Han, Quan Zhu, Xiangyuan Li   

  1. School of Chemical Engineering, Sichuan University, Chengdu 610065, China;Engineering Research Center of Combustion and Cooling for Aerospace Power, Ministry of Education, Sichuan University, Chengdu 610065, China
  • 通讯作者: Huaizhi Han,E-mail:hanhz@scu.edu.cn
  • 基金资助:
    This work was supported by the Scientific Research Start-up Funds for Introducing Talent at Sichuan University (20822041C4013).

Abstract: Although buoyancy and cracking reactions are strongly coupled in the active cooling process, most of the previous studies consider only one of these factors, and their coupling relationship has not been considerably examined. In this work, this coupling relationship was numerically investigated with complete consideration of different cases of heating, and in the view of energy transport and conversion. By comparing with the no-gravity case (NGC), the results indicate that buoyancy has a significant effect on the bottom-heated case (BHC) and side-heated case (SHC), but has little influence on the top-heated case (THC) owing to the different magnitudes of secondary flow. The heat transfer of the BHC and SHC was significantly enhanced by the secondary flow, but their energy conversion was simultaneously impaired. The conversion of the BHC and SHC was approximately half that of the THC and NGC. For all cases, by analyzing the energy transport ways, the cross section can be classified into three regions in the heating direction. Laminar conduction dominates in region I, but gradually fails in region II, where its role is replaced by other energy transport ways. In region III, convection dominates the energy transport for BHC and SHC, whereas turbulence dominates for THC and NGC.

Key words: Heat transfer, Computational fluid dynamics (CFD), Buoyancy, Hydrocarbons

摘要: Although buoyancy and cracking reactions are strongly coupled in the active cooling process, most of the previous studies consider only one of these factors, and their coupling relationship has not been considerably examined. In this work, this coupling relationship was numerically investigated with complete consideration of different cases of heating, and in the view of energy transport and conversion. By comparing with the no-gravity case (NGC), the results indicate that buoyancy has a significant effect on the bottom-heated case (BHC) and side-heated case (SHC), but has little influence on the top-heated case (THC) owing to the different magnitudes of secondary flow. The heat transfer of the BHC and SHC was significantly enhanced by the secondary flow, but their energy conversion was simultaneously impaired. The conversion of the BHC and SHC was approximately half that of the THC and NGC. For all cases, by analyzing the energy transport ways, the cross section can be classified into three regions in the heating direction. Laminar conduction dominates in region I, but gradually fails in region II, where its role is replaced by other energy transport ways. In region III, convection dominates the energy transport for BHC and SHC, whereas turbulence dominates for THC and NGC.

关键词: Heat transfer, Computational fluid dynamics (CFD), Buoyancy, Hydrocarbons