3D numerical study and comparison of thermal-flow performance of various annular finned-tube designs
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Tarih
2022
Dergi Başlığı
Dergi ISSN
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Yayıncı
Shanghai Jiaotong University
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
With the increase of heat transfer problems in marine vehicles and submerged power stations in oceans, the search for an efficient finned-tube heat exchanger has become particularly important. The purpose of the present investigation is to analyze and compare the thermal exchange and flow characteristics between five different fin designs, namely: a concentric circular finned-tube (CCFT), an eccentric circular finned-tube (ECFT), a perforated circular finned-tube (PCFT), a serrated circular finned-tube (SCFT), and a star-shaped finned-tube (S-SFT). The fin design and spacing impact on the thermal-flow performance of a heat exchanger was computed at Reynolds numbers varying from 4,300 to 15,000. From the numerical results, and when the fin spacing has been changed from 2 to 7 mm, an enhancement in the Colburn factor and a reduction in the friction factor and fin performances were observed for all cases under study. Three criteria were checked to select the most efficient fin design: the performance evaluation criterion PEC, the global performance criterion GPC, and the mass global performance criterionMG. Whatever the value of Reynolds number, the conventional CCFT provided the lowest performance evaluation criterion PEC, while the SCFT gave the highest amount of PEC. The most significant value of GPC was reached with the ECFT; however, GPC remained almost the same for CCFT, PCFT, SCFT, and S-SFT. In terms of the mass global performance criterion, the S-SFT provides the highest MGpcas compared with the full fins of CCFT (41–73% higher) and ECFT (29–54% higher). Thus, the heat exchanger with S-SFT is recommended to be used in the cooling of offshore energy systems.
Açıklama
Anahtar Kelimeler
Eccentric fins; Finned-tube designs; Perforated fins; Star-shaped fins; Thermal-flow performance
Kaynak
Journal of Ocean Engineering and Science
