| 摘要 |
PURPOSE:To improve the evaporation heat transfer rate by dripping of liquid refrigerant onto the top surface of an inner tube by a structure wherein continuous convexity and/or concavity are provided onto the inner surface of an outer tube in a heat exchanger tube consisting of the inner and outer tubes. CONSTITUTION:The titled heat exchanger tube consists of an inner tube 1 and an outer tube 2 and a smooth tube 3 is employed as the inner tube 1. The continuous spiral convexity 3 and concavity 4 are provided onto the inner surface of the outer tube 2 as continuous convexity and/or concavity. Liquid refrigerant 5 flows not only in the direction A of axes of the inner and outer tubes 1 and 2 but also in the direction B along the spiral convexity 3 and concavity 4 onto the inner surface of the outer tube 2. Consequently, the liquid refrigerant 5 rises along the inner surface of the outer tube 2 and drips onto the top surface 6 of the inner tube 1 by gravity at the upper portion of the inner surface in the midway of its rise along the inner surface of the outer tube 2, resulting in covering the whole outer periphery of the inner tube 1 with the thin dripped liquid refrigerant film 7. Thus, the evaporating action is done over the whole periphery of the inner tube. |
