Numerical Simulation of the Condensation Flow of the Isobutane (R600a) inside Microchannel

Abstract

A numerical investigation of the condensing flow of isobutane inside microchannel has been performed. Impact of mass flux, hydraulic diameter, and vapor quality on the heat transfer rate and pressure drop is determined. To this purpose, steady-state numerical simulations of condensation flow of isobutane have been performed at mass fluxes ranging from 200 to 600 kg/m²s inside a single circular microchannel with varying diameter. Similar to the usual operation conditions, the simulations have been conducted for constant saturation temperature and constant wall heat flux as the thermal boundary condition. The proposed model has been based on the volume of fluid approach, which is an interface tracking method. The Lee model has been used to model the phase change mass transfer at the interface. A verification study has been performed by comparing the proposed model results with the experimental and visual data available in the literature. The currently available correlations are assessed by comparisons with the simulation results. Based on the presently validated simulations, a new correlation has been proposed for the heat transfer coefficient and pressure drop of isobutane condensing flow inside small-scale channels. This is a novel aspect of the present paper, since such a correlation does not yet exist.

Acknowledgements

The author Anıl Başaran thanks TUBITAK (The Scientific and Technological Research Council of Turkey) for the awarded grant for a research fellowship at the Center of Flow Simulation, Düsseldorf University of Applied Sciences, Düsseldorf, Germany.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Anil Basaran

Anil Basaran is a Ph.D. student at the Department of Mechanical Engineering of Manisa Celal Bayar University (MCBU), Turkey, working currently at the Faculty of Engineering of MCBU as research assistant. He has also visited Center of Flow Simulation in Düsseldorf, Germany for 6 months. His research fields are related to design of microchannel heat exchangers for commercial refrigerators. He completed his M.Sc. studies in 2012 with a thesis on the effects of using different refrigerants on the performance of the Organic Rankine Cycle.

Ali Cemal Benim

Ali Cemal Benim received his B.Sc. and M.Sc. in Mechanical Engineering from the Bosphorus University of Istanbul, Turkey, and Ph.D. degree from the University of Stuttgart, Germany in 1988. Following his Postdoctoral period at the University of Stuttgart, he joined ABB Turbo Systems Ltd. in Baden, Switzerland in 1990. He was the Manager of the Computational Flow and Combustion Modeling group. Since 1996, he is Professor for Flow Simulation and Energy Technology at the Düsseldorf University of Applied Sciences, Germany.

Ali Yurddas

Ali Yurddas is an assistant professor at the Department of Mechanical Engineering of Manisa Celal Bayar University (MCBU), Turkey. He received Ph.D. degree from the MCBU Department of Mechanical Engineering in 2013. His research is focused on the computational fluid dynamics, thermodynamics and heat transfer processes, arecent field of interest being the numerical analysis of heat transfer performance of nano-fluids in thermal systems such as solar collectors.