SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2023, Vol. 60 ›› Issue (8): 173-185.DOI: 10.1016/j.cjche.2023.02.005

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Numerical simulation of flow and heat transfer of n-decane in sub-millimeter spiral tube at supercritical pressure

Jiahao Xing, Huaizhi Han, Ruitian Yu, Wen Luo   

  1. 1. School of Chemical Engineering, Sichuan University, Chengdu 610065, China;
    2. Engineering Research Center of Combustion and Cooling for Aerospace Power, Ministry of Education, Sichuan University, Chengdu 610065, China
  • Received:2022-10-18 Revised:2023-02-02 Online:2023-10-28 Published:2023-08-28
  • Contact: Huaizhi Han,E-mail:hanhz@scu.edu.cn
  • Supported by:
    The authors gratefully acknowledge the support by the Scientific Research Start-up Funds for introducing Talent in the Sichuan University (20822041C4014) and National Science and Technology Major Project of China (2017-I-0004-0004).

Numerical simulation of flow and heat transfer of n-decane in sub-millimeter spiral tube at supercritical pressure

Jiahao Xing, Huaizhi Han, Ruitian Yu, Wen Luo   

  1. 1. School of Chemical Engineering, Sichuan University, Chengdu 610065, China;
    2. 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:
    The authors gratefully acknowledge the support by the Scientific Research Start-up Funds for introducing Talent in the Sichuan University (20822041C4014) and National Science and Technology Major Project of China (2017-I-0004-0004).

Abstract: The flow and heat transfer characteristics of n-decane in the sub-millimeter spiral tube (SMST) at supercritical pressure (p = 3 MPa) are studied by the RNG k -ε numerical model in this paper. The effects of various Reynolds numbers (Re) and structural parameters pitch (s) and spiral diameter (D) are analyzed. Results indicate that the average Nusselt number (f) and friction factor (Nu) increase with an increase in Re, and decrease with an increase in D/d (tube diameter). In terms of the structural parameter s/d, it is found that as s/d increases, the Nu and f first increase, and then decrease. and the critical structural parameter is s/d = 4. Compared with the straight tube, the SMST can improve Nu by 34.8% at best, while it can improve f by 102.1% at most. In addition, a comprehensive heat transfer coefficient is applied to analyze the thermodynamic properties of SMST. With the optimal structural parameters of D/d = 6 and s/d = 4, the comprehensive heat transfer factor of supercritical pressure hydrocarbon fuel in the SMST can reach 1.074. At last, correlations of the average Nusselt number and friction factor are developed to predict the flow and heat transfer of n-decane at supercritical pressure.

Key words: Sub-millimeter spiral tube, Supercritical pressure, Numerical simulation, Heat transfer performance

摘要: The flow and heat transfer characteristics of n-decane in the sub-millimeter spiral tube (SMST) at supercritical pressure (p = 3 MPa) are studied by the RNG k -ε numerical model in this paper. The effects of various Reynolds numbers (Re) and structural parameters pitch (s) and spiral diameter (D) are analyzed. Results indicate that the average Nusselt number (f) and friction factor (Nu) increase with an increase in Re, and decrease with an increase in D/d (tube diameter). In terms of the structural parameter s/d, it is found that as s/d increases, the Nu and f first increase, and then decrease. and the critical structural parameter is s/d = 4. Compared with the straight tube, the SMST can improve Nu by 34.8% at best, while it can improve f by 102.1% at most. In addition, a comprehensive heat transfer coefficient is applied to analyze the thermodynamic properties of SMST. With the optimal structural parameters of D/d = 6 and s/d = 4, the comprehensive heat transfer factor of supercritical pressure hydrocarbon fuel in the SMST can reach 1.074. At last, correlations of the average Nusselt number and friction factor are developed to predict the flow and heat transfer of n-decane at supercritical pressure.

关键词: Sub-millimeter spiral tube, Supercritical pressure, Numerical simulation, Heat transfer performance