Calculating Film Condensation Performance in Tapered Plate Condensers Combining the Laminar and Turbulent Film Flow Regimes

Abstract Condensation is a widely utilized phenomenon, prized for its high heat flux capabilities in HVAC, industrial, power generation, and heat dissipation applications. Improving heat transfer in condenser designs can be widely beneficial in these areas. One approach to achieving this is to utilize a converging taper to enhance interfacial shear, leading to improved heat transfer through a condensate film-thinning effect. This study proposes a new approach to modeling the performance of tapered plate condensers by coupling the laminar and turbulent film regimes. An interpolation function in the form of a sigmoid is used to smoothly transition between the laminar and turbulent film regimes. The approach relies on an open-source implementation of Powell's hybrid algorithm to solve the arising set of nonlinear governing equations for film condensation. The key governing equations describing the liquid film growth and heat transfer in film condensation were adapted from well-established and tested literature. The present model was compared to available correlations and experimental data and reproduces local variations in the heat transfer coefficient accurately. A parameter study was conducted with the present model to show the predicted performance characteristics in tapered plate condensers. The results of this study show an enhancement in the average heat transfer coefficient of up to 35–60% can be achieved depending on operational and geometric conditions. Generally, increased taper angles lead to larger heat transfer enhancement.