%0 Journal Article
%A Seiler, Jan
%A Lanzerath, Franz
%A Jansen, Christoph
%A Bardow, André
%T Only a wet tube is a good tube: understanding capillary-assisted thin-film evaporation of water for adsorption chillers
%J Applied thermal engineering
%V 147
%@ 1359-4311
%C Amsterdam [u.a.]
%I Elsevier Science
%M FZJ-2020-02335
%P 571 - 578
%D 2019
%X Efficient evaporation of water at low temperatures is challenging due to its low saturation pressure. As a consequence, the preferred evaporation by nucleate boiling can only be achieved at the cost of high superheats. However, low superheats can still lead to efficient evaporation by thin-film evaporation. In this work, we experimentally characterize the heat transfer for thin-film evaporation on coated copper tubes, which use capillary action to create a thin film on their surface. The overall heat transfer through the tubes is determined at all filling levels for evaporator inlet temperatures of 10, 15 and 20 °C with varied driving force. Our experiments reveal that poor coatings suffer from dry-out at high driving forces whereas tubes with good coatings remain fully wetted even at high driving force. Furthermore, we show the impact of surface properties on thin-film evaporation: high porosity, surface extension and roughness promote the creation of a thin film on the tube. Thereby, the heat transfer UA-value is increased up to a factor of 10.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000454974700051
%R 10.1016/j.applthermaleng.2018.08.024
%U https://juser.fz-juelich.de/record/877620