社団法人日本機械学会 Acta Medica Okayama 0387-5016 57 534 1991 非共沸混合冷媒R114/R113の水平二重管環状部における凝縮 : 実験結果 249 256 EN Shigeru Nozu Kouichi Ozaki Hideo Inaba Hiroshi Honda Local heat transfer and pressure drop measurements were made during condensation of a nonazeotropic refrigerant mixture R114/R113 in the annuli of horizontal double-tube condensers. The inner tube was a 19.1mm o.d. corrugated copper tube with soldered wire fins on the outer surface. The outer tubes were smooth tubes with inside diameter D_i of 29.9 and 25.0mm. The pressure drop and the heat transfer coefficient based on the bulk vapor-to-wall temperature difference were considerably smaller for R114/R113 than for R113. The vapor phase mass transfer coefficient β_n was higher for larger test fluid mass velocity G and D_i. At constant values of G and D_i, β_n was higher for larger condensation mass flux. The radial distribution of the vapor temperature was affected by the vapor velocity, becoming flatter at the outer part of the annulus and steeper near the liquid-vapor interface as the vapor velocity increased. No potential conflict of interest relevant to this article was reported.