Steam flow condensation has a wide range of applications in the industry such as air conditioning, refrigeration, and thermal power plants. Condensation of steam on superhydrophobic surfaces has shown notable heat transfer improvement compared to conventional hydrophilic surfaces. Dropwise condensation and increased droplet mobility is the main reason for thermal performance enhancement of superhydrophobic surfaces. Although there are considerable reports of enhanced thermal transport behavior of superhydrophobic surfaces on steam condensation, the literature lacks sufficient investigation on flow condensation of steam, such as the effect of average vapor quality change on heat transfer rate.

Unlike gravity-driven droplet departure in quiescent dropwise condensation, droplet departure sizes in flow condensation are governed by flow-droplet shear forces and droplet-surface adhesive forces. This work experimentally investigates the steam flow condensation on nanotextured superhydrophobic and hydrophilic surfaces. The experimental setup consists of a reservoir, boiler, superheater, condensation chamber (test section), pre-condenser (to adjust the inlet quality), a post condenser, and a pump. A high aspect ratio microchannel was used as the test section. Different mass fluxes and inlet vapor qualities were used for the experimentations. Visualization studies were performed to analyze droplet dynamics such as droplet departure and coalescence in flow condensation. According to the obtained results, it was found that droplet diameter and departure frequency increase with the inlet mass flux.


Steam Flow Condensation on Superhydrophobic Surfaces in a High Aspect Ratio Microchannel

Division / Sponsors: 
Heat Transfer Division (HTD), Fluids Engineering Division (FED)

Heat Transfer Summer Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/HT/HT2020/volume/83709

18th International Conference on Nanochannels, Microchannels, and Minichannels
Paper Proceedings: https://asmedigitalcollection.asme.org/ICNMM/ICNMM2020/volume/83693

Fluids Engineering Division Summer Meeting
Paper Proceedings: https://asmedigitalcollection.asme.org/FEDSM/FEDSM2020/volume/83716

HT-ICNMM2020 - Virtual Conference, SHTC - Virtual Conference, FEDSM2020 - Virtual Conference

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