Onal, Busra Selenay and Kirkar, Safak Metin and Akgul, Dogan and Celen, Ali and Acikgoz, Ozgen and Dalkilic, Ahmet Selim and Kazi, Salim Newaz and Wongwises, Somchai (2022) Heat transfer and pressure drop characteristics of two phase flow in helical coils. Thermal Science and Engineering Progress, 27. ISSN 2451-9049, DOI https://doi.org/10.1016/j.tsep.2021.101143.
Full text not available from this repository.Abstract
This paper presents a review on heat transfer coefficient and pressure drop during condensation and boiling in helically coiled tubes. The geometric parameters such as coil diameter, coil pitch and operating parameters containing saturation temperature, system pressure, mass flux, heat flux and vapor quality have significant effects on the heat transfer characteristics. The frictional pressure drop during flow boiling increases with increasing vapor quality and mass flux, and decreases with increasing system pressure. Also, the effect of the curvature on the two-phase frictional multiplier is negligible. The frictional pressure drop in condensation increased with increasing average vapor quality and mass flux, and decreased with increasing saturation temperature. According to the results reported, heat flux had little effect on the pressure drop during condensation. Flow boiling heat transfer coefficient in helical coils of large diameter showed the similar characteristics and trend with the straight tube as the system pressure decreased. Lockhart-Martinelli parameter was generally preferred to be used by the authors as a function in the correlations to predict flow boiling heat transfer coefficient. There was a decrease in the average Nusselt number with increasing heat flux for the constant Dean number during condensation. This reduction in the average Nusselt number indicated that the turbulence effect created by the secondary flow in the helically coiled tubes eliminated the effects caused by the difference in density. The correlations used for determination of Nusselt number and pressure drop in helical coils with their major findings are presented in details.
| Item Type: | Article |
|---|---|
| Funders: | Yildiz Technical University [Grant No: FOA-2019-3582], National Science and Technology Development Agency (NSTDA) under the Research Chair Grant, Thailand Science Research and Innovation (TSRI) under the Fundamental Fund 2022 |
| Uncontrolled Keywords: | Condensation; Boiling; Helical coils; Heat transfer coefficient; Heat transfer; Pressure drop |
| Subjects: | G Geography. Anthropology. Recreation > GE Environmental Sciences T Technology > TA Engineering (General). Civil engineering (General) T Technology > TJ Mechanical engineering and machinery |
| Divisions: | Faculty of Engineering > Department of Mechanical Engineering |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 28 Aug 2023 07:56 |
| Last Modified: | 27 Nov 2024 01:44 |
| URI: | http://eprints.um.edu.my/id/eprint/43097 |
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