Condensing heat transfer characteristics of aluminum flat tube

Aluminum brazed heat exchangers are used widely in automobile air conditioning systems. Usually, this kind of heat exchanger is made of a flat tube with several independent passages in the cross-section, and formed into a serpentine or a parallel flow geometry. In these heat exchangers, a multitude of corrugated fins with louvers are inserted into the gaps between flat tubes. As a result of their high performance, some companies are starting to use extruded brazed aluminum heat exchangers in heating, ventilating and air conditioning applications. The purpose of this investigation is to provide the basic condensing heat transfer data for the extruded aluminum flat tube. Four different flat tubes and one micro fin tube were employed in this series of experimental studies. HFC-134a and HCFC-22 were the working fluids used. Our results were closest to Shah's correlation in the low quality region.