Condensation heat transfer and pressure drop characteristics of R-600a in horizontal smooth and helically dimpled tubes

Sarmadian, A, Shafaee, M, Mashouf, H and Mohseni, S G (2017) Condensation heat transfer and pressure drop characteristics of R-600a in horizontal smooth and helically dimpled tubes. Experimental Thermal and Fluid Science, 86. pp. 54-62. ISSN 0894-1777

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Abstract

In the present study, condensation heat transfer and frictional pressure drops of refrigerant R-600a (iso-butane) inside a helically dimpled tube and a plain tube of internal diameter 8.3 mm were measured and analyzed. All tests were performed at different vapor qualities up to 0.82 and average saturation temperatures ranging between 38 and 42 °C. Refrigerant mass fluxes varied in the range of 114–368 kg/m2 s. The inner surface of the helically dimpled tube has been designed and reshaped through three-dimensional material surface modifications consists of both shallow and deep protrusions which are placed evenly in helical directions on the tube wall. The experimental results show that the heat transfer coefficients of the dimpled tube are 1.2–2 times of those in smooth tube with a pressure drop penalty just ranging between 58% and 195. The highest heat transfer coefficient is occurred at vapor quality of 0.53 and mass flow rate of 368 kg/m2 s. On the other hand, the maximum increase of pressure drop takes place at vapor quality of 0.55 and mass flow rate of 368 kg/m2 s.

Item Type: Article
Keywords: Condensation, Dimpled tube, R-600a, Heat transfer, Pressure drop
Schools and Departments: School of Engineering and Informatics > Engineering and Design
Research Centres and Groups: Dynamics, Control and Vehicle Research Group
The Sussex Energy Group
Thermo-Fluid Mechanics Research Centre
Subjects: Q Science > QC Physics > QC0120 Descriptive and experimental mechanics > QC0145.2 Fluids. Fluid mechanics. General works
Q Science > QC Physics > QC0251 Heat > QC0310.15 Thermodynamics
T Technology > TA Engineering (General). Civil engineering (General) > TA0349 Mechanics of engineering. Applied mechanics > TA0357 Applied fluid mechanics
T Technology > TP Chemical technology > TP0480 Low temperature engineering. Cryogenic engineering. Refrigeration
Depositing User: Alireza Sarmadian
Date Deposited: 02 Oct 2018 13:35
Last Modified: 02 Jul 2019 13:49
URI: http://sro.sussex.ac.uk/id/eprint/79167

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