A comparison between hydrocarbons and traditional refrigerants during condensation inside a 4 mm ID smooth tube

This paper presents a heat transfer comparison between two promising refrigerants for HVAC and refrigeration: propane and propylene and some traditional HFC fluids, such as R134a, R410A, and R404A. The fluids were experimentally investigated during condensation inside a 4 mm ID horizontal smooth tube at several vapor qualities, saturation temperatures, and flow rates. A comparison between heat transfer coefficients and pressure drop was carried on in order to answer the question if HCs could be viable substitutes of the current refrigerants. Then, some classical correlations were assessed and the dominant flow regimes occurred during condensation were evaluated.