SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2019, Vol. 27 ›› Issue (12): 2892-2899.DOI: 10.1016/j.cjche.2019.07.006

• Fluid Dynamics and Transport Phenomena • Previous Articles     Next Articles

Performance comparison of heat exchangers using sextant/trisection helical baffles and segmental ones

Yaping Chen1, Hongling Tang1,2, Jiafeng Wu1, Huaduo Gu1, Shifan Yang1   

  1. 1 Engineering Research Center of BEEE, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China;
    2 Hefei Yidu Education Consulting Co. Ltd, TAL Education Group, Hefei 230031, China
  • Received:2019-01-26 Revised:2019-05-13 Online:2020-03-17 Published:2019-12-28
  • Contact: Yaping Chen
  • Supported by:
    Supported by the National Natural Science Foundation of China (51776035).

Performance comparison of heat exchangers using sextant/trisection helical baffles and segmental ones

Yaping Chen1, Hongling Tang1,2, Jiafeng Wu1, Huaduo Gu1, Shifan Yang1   

  1. 1 Engineering Research Center of BEEE, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China;
    2 Hefei Yidu Education Consulting Co. Ltd, TAL Education Group, Hefei 230031, China
  • 通讯作者: Yaping Chen
  • 基金资助:
    Supported by the National Natural Science Foundation of China (51776035).

Abstract: The shell side flow fields of both sextant and trisection helical baffle heat exchangers are presented on meridian and multilayer hexagon slices. It verifies that the performance of sextant schemes is better than those of the other kinds of helical baffle heat exchangers. The main mechanisms are due to the restricted leakage flow in the minimized gaps with increased baffle number and by one row of tubes dampen the leakage flow in the circumferential overlapped area of the adjacent helical baffles. The performance features were simulated on two different angled sextant helical heat exchangers and each compared with two trisection ones of either identical helical pitch or identical incline angle. The results verified that the performances of helical heat exchangers are mainly determined by the helical pitch rather than the baffle incline angle. The average values of comprehensive index hoΔpo-1/3 of the trisection helical schemes T-24.1° and T-29.7° are correspondingly 3.47% and 3.34% lower than those of the sextant ones X-20° and X-25° with identical helical pitches. The comparison results show that the average values of shell side h.t.c. ho and comprehensive index hoΔpo-1/3 of the optimal dual helix sextant scheme DX30° are respectively 7.22% and 23.56% higher than those of the segment scheme S100.

Key words: Heat transfer, Computational fluid dynamics, Convection, Helical baffle heat exchangers, Sextant helical baffles

摘要: The shell side flow fields of both sextant and trisection helical baffle heat exchangers are presented on meridian and multilayer hexagon slices. It verifies that the performance of sextant schemes is better than those of the other kinds of helical baffle heat exchangers. The main mechanisms are due to the restricted leakage flow in the minimized gaps with increased baffle number and by one row of tubes dampen the leakage flow in the circumferential overlapped area of the adjacent helical baffles. The performance features were simulated on two different angled sextant helical heat exchangers and each compared with two trisection ones of either identical helical pitch or identical incline angle. The results verified that the performances of helical heat exchangers are mainly determined by the helical pitch rather than the baffle incline angle. The average values of comprehensive index hoΔpo-1/3 of the trisection helical schemes T-24.1° and T-29.7° are correspondingly 3.47% and 3.34% lower than those of the sextant ones X-20° and X-25° with identical helical pitches. The comparison results show that the average values of shell side h.t.c. ho and comprehensive index hoΔpo-1/3 of the optimal dual helix sextant scheme DX30° are respectively 7.22% and 23.56% higher than those of the segment scheme S100.

关键词: Heat transfer, Computational fluid dynamics, Convection, Helical baffle heat exchangers, Sextant helical baffles