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

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

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.

Cite this article

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]. Journal of Thermal Science, 2025 , 34(1) : 24 -33 . DOI: 10.1007/s11630-024-2087-9

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