A Numerical Study to Understand Heat Transfer Characteristics of the Condensing Flow of Climate Friendly R290 Refrigerant Inside the Microchannel

The current study involves a series of numerical simulations aimed at elucidating the heat transfer characteristics associated with the condensing flow of R290 (propane) within microchannels. Specifically, circular microchannels with various diameters were examined to understand the effects of hydraulic diameters on heat transfer coefficients. Different mass fluxes (200–1200 kg/m2s) and inlet vapor qualities (0.3–0.9) were considered for a comprehensive examination. To accurately solve the two-phase flow dynamics inherent in condensation, the Volume of Fluid (VOF) model was employed, coupled with the Lee model to account for phase change at the saturation temperature. It is worth noting that within considered cases in numerical simulations, surface tension forces assume importance relative to other forces, in contrast to conventional channels. The accuracy of the numerical predictions was assessed against existing experimental data in the literature, revealing an agreement between the present simulations and the experimental data in the literature. It is found that the heat transfer coefficient increases with increasing mass flux and inlet vapor quality.