CONDENSING HEAT-TRANSFER CHARACTERISTICS OF ALUMINUM FLAT TUBE

Aluminum brazed heat exchangers are used widely in automobile air cond itioning systems. Usually, this kind of heat exchanger is made of a fl at tube with several independent passages in the cross-section, and fo rmed into a serpentine or a parallel flow geometry. In these heat exch angers, a multitude of corrugated fins with louvers are inserted into the gaps between flat tubes. As a result of their high performance, so me companies are starting to use extruded brazed aluminum heat exchang ers in heating, ventilating and air conditioning applications. The pur pose of this investigation is to provide the basic condensing heat tra nsfer data for the extruded aluminum hat tube. Four different flat tub es and one micro fin tube were employed in this series of experimental studies. HFC-134a and HCFC-22 were the working fluids used. Our resul ts were closest to Shah's correlation in the low quality region. (C) 1 997 Elsevier Science Ltd.