扁平微組多孔管内における純冷媒HFC134aの凝縮に関する実験的研究

In the present study, the heat transfer characteristics are investigated experimentally for condensation of pure refrigerant HFC134a in a 955 mm long multi-port extruded tube of 0.72 mm in hydraulic diameter. The experiments were carried out in the ranges of mass velocity of G = 100∼700 kg/m<SUP>2</SUP>s and vapor quality of x = 1.0∼0.0 at a constant inlet pressure of 1.7MPa.The refrigerant mass flow rate and the total pressure drop over the test tube were measured. The wall temperature and the wall heat flux in every 75 mm long subsection were also measured. At first, a correlation for local frictional pressure drop, which is assumed to be the same functional form as the Chisholm correlation, is obtained from the measured total pressure drop. Next, the local heat transfer coefficient in every subsection was evaluated. Then, data of the local heat transfer coefficient were compared with correlations of Haraguchi et al. (1994) and Moser et al. (1998).