Falling film evaporative heat transfer on CNT composite coatings

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.This study aims to enhance falling film type evaporation heat transfer on metal surfaces by coating with multi-walled carbon nanotubes (MWCNTs). In order to do this, multi-walled carbon nanotube/Copper (MWCNT/Cu) composite powders fabricated and composites are sprayed on the surface of Copper plates and are sintered. The falling type evaporation heat transfer tests were performed under working conditions of absorption chiller for water(Pressure: 4 mm Hg). Then the heat transfer tests were performed with various contents of MWCNT coated specimens and falling flow rates of refrigerants. Based on the results, it can be inferred that evaporation heat transfer was enhanced due to the porous structure of the surface coating and the excellent heat transfer characteristics of the MWCNTs.