水平内面溝付管内の冷媒HCFC22の蒸発熱伝達と圧力損失

抄録

The evaporation heat heat transfer and pressure drop inside seven kinds of grooved horizontal tubes with 7.0 mm outside diameter and 60 to 100 grooves with 0.15 to 0.21 mm in height and 3 to 18 degree of lead angle, were obtained. The test section, 300 mm in length, was heated by condensing CFC 114 vapor on the outside of tube. HCFC 22 was used as a working fluid. Evaporating pressure was 0.49MPa, heat flux was 9.3 kW/ m², vapor quality was varied from 0.1 to 0.9, and mass velocity was varied from 86 to 345 kg/(m²s). The empirical correlations to predict heat transfer coefficient and pressure drop were proposed. Increasing the modified bond number, the heat transfer coefficient decreases in the range of the modified bond number experimented. Pressure drop isn't influenced by the groove geometries except for lead angle.