Heat transfer and pressure drop characteristics of HFC quaternary refrigerant mixtures inside horizontal enhanced surface tubing

Heat transfer characteristics of two-phase flow condensation and boiling of quaternary (four components) refrigerant mixtures, on air/refrigerant horizontal enhanced surface tubing are presented, discussed and compared to other refrigerants proposed as substitutes for CFC-502, such as R-507 and R-407B. Heat transfer characteristics, such as average heat transfer coefficients, as well as pressure drops of ternary azeotropic refrigerant mixtures, flow condensation and boiling inside enhanced surface tubing, were predicted. Experimental data showed that our proposed quaternary blend has a superior boiling heat transfer coefficient and higher pressure drop compared to CFC-502. Copyright (C) 1996 Elsevier Science Ltd.