The influence of fin structure and fin density on the condensation heat transfer of R134a on single finned tubes and in tube bundles

Beitrag in einer Fachzeitschrift
(Originalarbeit)


Details zur Publikation

Autor(en): Al-Badri A, Bär A, Gotterbarm A, Rausch MH, Fröba AP, Fröba AP
Zeitschrift: International Journal of Heat and Mass Transfer
Verlag: Elsevier
Jahr der Veröffentlichung: 2016
Band: 100
Seitenbereich: 582-589
ISSN: 0017-9310
Sprache: Englisch


Abstract


The influence of fin structure and density on the condensation heat transfer of refrigerant 1,1,1,2-tetrafluoroethane (R134a) is investigated on single finned tubes and in corresponding bundles. Experiments have been performed on standard and enhanced finned tubes with 39, 48, and 56 fins per inch (FPI) and different fin heights. The enhanced finned tubes are based on the standard ones, and are characterized by a non-uniform fin structure. The condensation heat transfer coefficient (HTC) is determined for single tubes as well as for each row of the tube bundles and compared with predictions from analytical models. In the single tube measurements, the enhanced finned tubes showed distinctly higher HTCs than the standard finned tubes. Different condensation flow modes have been observed during the tube bundle experiments where the additional structures on the fin flank of the enhanced finned tubes promote sheet mode condensation. It has been demonstrated that the standard finned tubes show a lower decrease in the condensation HTC with increasing tube row number in the bundle than the enhanced finned tubes. Among the standard finned tubes, the one with 48 FPI and larger fin height exhibits the highest HTCs for single tube and tube bundle experiments. The increase in the fin height seems to delay the formation of sheet mode condensation and thus to increase the condensation HTC. Among the enhanced finned tubes, the tube with 39 FPI yields the highest HTCs for both single tube and tube bundle measurements. Low fin density and large fin height obviously tend to keep the insulating effect of retained condensate in the fin channels low. (C) 2016 Elsevier Ltd. All rights reserved.



FAU-Autoren / FAU-Herausgeber

Al-Badri, Alaa
Lehrstuhl für Technische Thermodynamik
Fröba, Andreas Paul Prof. Dr.-Ing.
Professur für Advanced Optical Technologies - Thermophysical Properties
Fröba, Andreas Paul Prof. Dr.-Ing.
Lehrstuhl für Advanced Optical Technologies - Thermophysical Properties
Rausch, Michael Heinrich Dr.-Ing.
Professur für Advanced Optical Technologies - Thermophysical Properties


Zusätzliche Organisationseinheit(en)
Erlangen Graduate School in Advanced Optical Technologies


Zitierweisen

APA:
Al-Badri, A., Bär, A., Gotterbarm, A., Rausch, M.H., Fröba, A.P., & Fröba, A.P. (2016). The influence of fin structure and fin density on the condensation heat transfer of R134a on single finned tubes and in tube bundles. International Journal of Heat and Mass Transfer, 100, 582-589. https://dx.doi.org/10.1016/j.ijheatmasstransfer.2016.04.087

MLA:
Al-Badri, Alaa, et al. "The influence of fin structure and fin density on the condensation heat transfer of R134a on single finned tubes and in tube bundles." International Journal of Heat and Mass Transfer 100 (2016): 582-589.

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Zuletzt aktualisiert 2018-27-06 um 15:23