Options
Development of numerical model to study the effect of condensate liquid layer on condensation heat transfer of R134a in minichannel
Journal
Heat and Mass Transfer/Waerme- und Stoffuebertragung
ISSN
09477411
Date Issued
2022-11-01
Author(s)
Pramanick, Sourav
Dey, Prasenjit
Saha, Sandip K.
Abstract
Future space equipment and applications would require a high amount of heat dissipation. In such applications, minichannel, as an integral component of the compact cooling device, could play a significant role in maintaining the electronics temperature within a tolerable limit and reducing the spacecraft weight. The present study deals with condensation heat transfer in a two-dimensional minichannel with R134a as a working fluid. A novel numerical model capable of analysing the condensation of vapour in minichannel owing to the temperature difference and the change in local vapour pressure resulting from the flow passage contraction due to the developed liquid layer is proposed and validated with the existing literature. The Volume of Fluid (VOF) approach is used for two-phase interface tracking. The effects on the performance of the minichannel condensation process, thin liquid film layer development, and prediction of two-phase (liquid–vapour) interface profile due to variations in inlet vapour mass flux and minichannel diameter are investigated. The gravity effect is studied by considering five different conditions of 0, 0.5, 1, 5 and 9.81 m/s2. Additionally, three different inlet mass fluxes of 250 kg/m2.s, 500 kg/m2.s and 750 kg/m2.s are considered. For each mass flux, three different channel diameters are considered, viz. 1 mm, 2 mm and 3 mm at g = 0 and 9.81 m/s2. Outcomes of the study show that the average Nusselt number increases as inlet vapour mass flux increases. The increment in inlet vapour mass flux causes significantly delayed fluctuations in the flow. It is observed that as the minichannel diameter increases, the average heat transfer coefficient reduces significantly.