An empirical study on condensation process and heat transfer enhancement under corona discharge: A visualization-based investigation

Abstract

The gas-liquid phase transition process is pivotal across applications, from building thermal regulation to fostering low-carbon urban environments. This study pioneers a corona discharge-based approach to enhance dropwise condensation heat transfer on surfaces with diverse wettability. A dedicated experimental platform investigates and improves surface droplet condensation through corona discharge. The research meticulously analyzes nucleation, growth, coalescence, and shedding behaviors on varied wettability surfaces. Empirical exploration validates corona discharge's efficacy in enhancing condensation. The study elucidates corona discharge's mechanism in augmenting condensation on diverse wettability surfaces. Negative corona discharge significantly heightens nucleation density and shedding rate on hydrophobic surfaces. A parametric analysis optimizes a holistic solution integrating active and passive technologies. Surface wettability profiles lead to divergent condensation outcomes. Hydrophilic surfaces exhibit slow shedding, elevating thermal resistance. Hydrophobic surfaces facilitate rapid shedding but face elevated nucleation barriers. Super-hydrophilic surfaces offer low resistance but thicken with condensation speed. The study establishes corona discharge's proportionate enhancement on hydrophobic surface condensation with increased negative corona electric field intensity. This research amalgamates theoretical and empirical insights, forming a robust basis for hydrophobic surface heat exchanger design in power engineering and engineering thermophysics applications.