Boiling and Condensation Heat Transfer for New Refrigerants HFE245mc and HFE143m Flowing in Horizontal Tubes

抄録

Hydrofluoroethers (HFEs) have recently been proposed as substitutes to conventional refrigerants including HFCs, since HFEs have zero ozone depletion potential and also smaller global warming potential. HFE245mc and HFE143m are such substitutes to replace CFC114 especially for heat recovery heat pump systems and HFC134a for refrigerating systems, respectively. In the present study, experiments were made on boiling and condensation heat transfer for HFE245mc and HFE143m flowing inside horizontal smooth tubes. For each new refrigerant, there was found no peculiar difference from conventional refrigerants in the characteristics of boiling and condensation heat transfer, as results of comparisons of measured local boiling and condensation heat transfer coefficients with respective correlations applicable to conventional refrigerants; the authors' correlation for boiling and the Haraguchi et al.'s correlation for condensation Comparing the values calculated from the correlations, the heat transfer coefficient for HFE245mc showed to be higher than or equal to that of CFC114 for boiling and condensation. Similarly, the heat transfer coefficient for HFE143m showed to be almost equal to that of HFC134a for boiling and condensation. From the standpoint of heat transfer, therefore, there was no problem in the use of HFE245mc and HFE143m as the alternative refrigerants to CFC114 and HFC134a, respectively.