Numerical Study of Flow and Heat Transfer Characteristics of Shell-and-Tube Molten Salt Electric Heater with Circularly Perforated Baffles

  • LIN Yongjie ,
  • ZHANG Cancan ,
  • WU Yuting ,
  • ZHANG Yi ,
  • LU Yuanwei
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  • Key Laboratory of Heat Transfer and Energy Conversion, National User-Side Energy Storage Innovation Research and Development Center, Beijing University of Technology, Beijing 100124, China

网络出版日期: 2025-01-09

基金资助

This work is supported by National Key Research and Development Program of China (2022YFB2405203), Science and Technology General Project of Beijing Municipal Education Commission (KM202210005016), Inner Mongolia Science and Technology Major Project (2021SZD0036), Beijing Natural Science Foundation (3242015).

版权

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2024

Numerical Study of Flow and Heat Transfer Characteristics of Shell-and-Tube Molten Salt Electric Heater with Circularly Perforated Baffles

  • LIN Yongjie ,
  • ZHANG Cancan ,
  • WU Yuting ,
  • ZHANG Yi ,
  • LU Yuanwei
Expand
  • Key Laboratory of Heat Transfer and Energy Conversion, National User-Side Energy Storage Innovation Research and Development Center, Beijing University of Technology, Beijing 100124, China

Online published: 2025-01-09

Supported by

This work is supported by National Key Research and Development Program of China (2022YFB2405203), Science and Technology General Project of Beijing Municipal Education Commission (KM202210005016), Inner Mongolia Science and Technology Major Project (2021SZD0036), Beijing Natural Science Foundation (3242015).

Copyright

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2024

摘要

对四种不同开孔率的管壳式熔盐电加热器的流动和换热特性进行了数值模拟。管壳式电加热器具有相同的几何结构和布管方式,且均采用单弓形折流板,但存在四种不同的折流板开孔率(φ),即0%、2.52%、4.06%、6.31%。结果表明,在折流板上合理开孔可以显著降低壳程流动压力损失,有效降低壳侧流动死区面积,并且能够明显消除电加热管表面存在的局部高温现象,但是换热系数略有下降。所有开孔方案与未开孔的基准方案相比,壳侧压降均有明显降低。特别是φ=6.31%时,在所有方案中表现最佳,其壳侧压降比未开孔方案降低至多50.50%。在计算范围内,φ=0%的对流换热系数最高,分别比φ=2.52%,4.06%,6.31%高5.26%~5.73%,5.14%~5.99%,7.31%~8.54%。所有开孔方案的综合指数hp1/3均比未开孔方案高,其中φ=6.31%的综合性能最好,综合指数比未开孔方案提高了15.29%~17.18%。

本文引用格式

LIN Yongjie , ZHANG Cancan , WU Yuting , ZHANG Yi , LU Yuanwei . Numerical Study of Flow and Heat Transfer Characteristics of Shell-and-Tube Molten Salt Electric Heater with Circularly Perforated Baffles[J]. 热科学学报, 2025 , 34(1) : 24 -33 . DOI: 10.1007/s11630-024-2087-9

Abstract

Numerical simulations of the flow and heat transfer characteristics of four shell-and-tube molten salt electric heaters with different perforation rates was conducted. Shell-and-tube electric heaters have the same geometry and tube arrangement, and all of them use single segmental baffles, but there exist four different baffle openings (φ), i.e., 0%, 2.52%, 4.06%, and 6.31%. The results indicated that the reasonable baffle opening could significantly reduce the shell-side pressure drop, effectively decreasing the shell-side flow dead zone area. They can eliminate the local high-temperature phenomenon on the surface of electric heating tubes, but the heat transfer coefficient is slightly decreased. All perforated schemes significantly reduce shell-side pressure drop compared to the baseline solution without open holes. In particular, the φ=6.31% scheme exhibits the optimal performance among all the schemes, with a maximum reduction of up to 50.50% in shell-side pressure drop relative to the unopened holes scheme. The heat transfer coefficient is the highest for φ=0%, exhibiting a range of 5.26% to 5.73%, 5.14% to 5.99%, and 7.31% to 8.54% higher than φ=2.52%, 4.06%, and 6.31%, respectively, within the calculated range. The composite index h/(Δp)1/3 was higher for all open-hole solutions than that for the unopened-hole solution. The best overall performance was for φ=6.31%, which improved the composite index by 15.29% to 17.18% over the unopened-hole solution.

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