- Volume 28 Issue 7
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Analysis on Wetting Behavior of A Lamellar Type Wet Channels in An Evaporative Heat Exchanger
층상구조를 가진 증발식 열교환기 습채널의 표면 젖음도 해석
- Received : 2016.03.10
- Accepted : 2016.06.17
- Published : 2016.07.10
One of the most important factors for determining the thermal performance of an evaporative cooling system is the wettability of the evaporative heat exchanger surface. Evaporation of a widely spread water film on the heat exchanger surface promotes heat transfer between the "dry" air and "wet" air passages. Hydrophilic coating is generally applied on the heat exchanger surfaces to increase the wettability of the heat exchanger surface and the COP of the evaporative cooling system. In this paper, a simple lamellar patterned structure is suggested to maximize the spreading of a water film on the vertically oriented walls. The capillary height of the lamellar structured grooves is analyzed through a theoretical model, and the results are compared with the numerical analysis through a finite element analysis tool, SE-FIT. A good agreement between the theoretical model and the numerical analysis can be observed as long as the channel depth is comparable to or larger than the channel width of the lamellar structure.
Evaporative heat exchanger;Hydrophilic surface;Surface wettability;Lamellar structure
- Lee, J. W., Lee, D.-Y., and Kang, B. H., 2004, Cycle simulation of a desiccant cooling system with a regenerative evaporative cooler, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 16, No. 6, pp. 566-573.
- Guo, X. C. and Zhao, T. S., 1998, A Parametric Study of an Indirect Evaporative Air Cooler, Int. Comm. Heat Mass Transfer, Vol. 25, No. 2, pp. 217-226. https://doi.org/10.1016/S0735-1933(98)00008-6
- Hoffman, A. S., 1996, Surface modification of polymers : Physical, chemical, mechanical and biological methods, Macromolecular Symposia, Vol. 101, No. 1, pp. 445-448.
Kuo, C.-C., Tseng, Y.-H., and Li, Y.-Y., 2006, Wettability and superhydrophilic
$TiO_2$film formed by chemical vapor deposition, Chemistry letters, Vol. 35, No. 4, pp. 356-357. https://doi.org/10.1246/cl.2006.356
- Scovazzo, P., Hoehn, A., and Todd, P., 2000, Membrane porosity and hydrophilic membrane-based dehumidification performance, Journal of Membrane Science, Vol. 167, No. 2, pp. 217-225. https://doi.org/10.1016/S0376-7388(99)00291-4
- Brakke, K., 1998, Surface Evolver Manual, Susquehanna University : Selinsgrove, PA.
- Bernardin, J., Mudawar, I., Walsh, C. B., and Franses, E., 1997, Contact angle temperature dependence for water droplets on practical aluminum surfaces, International Journal of Heat and Mass Transfer, Vol. 40, No. 5, pp. 1017-1033. https://doi.org/10.1016/0017-9310(96)00184-6
- de Gennes, P.-G., Brochard-Wyart, F., and Quere, D., 2004, Capillary and Wetting Phenomena : Drops, Bubbles, Pearls, Waves, Springer-Verlag, New York, pp. 43-48.
Supported by : 한국연구 재단