Gholamreza Bamorovat Abadi
Pusan National University, Jangjeon-dong, Gumjung-ku, Busan 609-735, Korea
Kyung Chun Kim
School of Mechanical Engineering, Pusan National University, Jangjeon-dong, Gumjung-ku, Busan 609-735, South Korea
This study experimentally investigates the degradation of the heat transfer coefficient of zeotropic mixtures during phase change in a plate heat exchanger with metal-foam-filled channels. The working fluids were pure R245fa and a zeotropic mixture of R245fa/R134a (0.6/0.4 molar ratio). The results show that the metal foams significantly increase the recovered heat, overall heat transfer coefficient, and effectiveness of the heat exchanger for mass flux ranging from 90 to 290 kg/m2s, but at the expense of increasing the pressure drop. The same improvement was observed for the mixture of refrigerants. The degraded heat transfer coefficient of the mixture compared to the pure refrigerants was recovered by the introduction of metal foams to the system. New correlations are proposed to predict the two-phase heat transfer coefficient of both pure R245fa and the refrigerant mixture in metal foam evaporators.