Journal of South China University of Technology (Natural Science Edition) ›› 2021, Vol. 49 ›› Issue (2): 33-39.doi: 10.12141/j.issn.1000-565X.190865

Special Issue: 2021年能源、动力与电气工程

• Energy, Power & Electrical Engineering • Previous Articles     Next Articles

Numerical Investigation of Heat Transfer Performance of Molten Salt-Based Nanofluids for Internal Flow#br#

HE Boshu1,2 YING Zhaoping1 SU Liangbin1 DING Guangchao1 HE Di1DUAN Zhipeng1   

  1. 1. School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China;
    2. School of Mechanical and Power Engineering, Cangzhou Jiaotong College, Huanghua 061199, Hebei, China
  • Received:2019-11-28 Revised:2020-08-11 Online:2021-02-25 Published:2021-02-01
  • Contact: 应兆平（1994），男，硕士，主要从事纳米流体流动换热、太阳能光热电站研究。 E-mail:zhaoping@bjtu.edu.cn
  • About author:何伯述（1964），男，博士，教授，主要从事太阳能利用、清洁煤燃烧研究。E-mail：hebs@bjtu.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(51576013)

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Abstract: To study the flow heat transfer characteristics of Al2O3-HITEC molten salt-based nanofluids in heating tubes with constant heat flux，a computational fluid dynamics ( CFD) simulation was carried out with the singlephase thermal dispersion model． The effects of nanoparticle additions with different mass fractions on the heat transfer performance of molten salt were analyzed，and the heat transfer performance variations were discussed from the respect of the thermal physical properties of the fluid． Comparisons of results show that the thermal dispersion model can be used to simulate the heat transfer performance of molten salt-based nanofluids． Simulations show that the temperature inside the tube with various nanofluids is lower than that with pure molten salt，and the temperature drop is the most obvious with the particle concentration of 0. 063% ． The temperature distributions at the four sections show that under the wall heat flux boundary，the temperature of molten salt with or without nanoparticles increases radially，while the temperature of molten salt-based nanofluids is lower than that of the pure molten salt，indicating nanofluids absorb and take away more heat energy． Moreover，compared with that of pure molten salt，the heat transfer performance of molten salt-based nanofluids increases，proving that the nanoparticle additions can improve the heat transfer performance of molten salt． However，the improvement is not proportional to the increase of nanoparticle concentration． Instead，the nanofluids with a mass fraction of 0. 063% show the greatest heat transfer enhancement，and the heat transfer coefficient in the fully developed region is 6. 5% higher than that of pure molten salt． Finally，the drastic change of specific heat capacity is found playing a key role in the change of heat transfer performance through analyzing the physical properties of molten salt and molten salt-based nanofluids．

Key words: molten salt-based nanofluids, thermal dispersion model, flow and heat transfer characteristics, numerical simulation

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