| 摘要 |
PURPOSE:To aim at enhancing the thermal conductivity without increase of the pressure loss as well as to improve the circulative property of the fluid while promoting seething and condensation by excavating two spiral grooves on the tube's inner wall in such a way that their tilt angles are opposite from the tube's axis. CONSTITUTION:This heat exchange tube 1 is provided with a number of projections 4 at its inner wall in spiral arrangement in such a way that their summits are directed approximately toward the tube's center. These projections are made by excavating two spiral grooves 2, 3 on the tube's inner wall with small pitches and opposite tilt angles from the axis of heat exchange tube, i.e. a right-hand thread and a left-hand thread. These projections can be provided with a form of square pyramid whose summits are situated at the intersecting points of upper edges of these two grooves 2, 3 by making these grooves in V- or U-shaped profile, and thereby a number of oblique crossing fluid passages are formed between projections to offer a heat exchange tube with enlarged inside surface area. |
