| 摘要 |
PURPOSE:To obtain high quality of the heat transfer rate by inducing the turbulence in fluid as well as to obtain a heat transfer pipe having the heat transfer surface construction of high durability, by a method wherein protuberance of which side being continuous circle or ellipse shape having curvature, are provided at the inside of pipes, and rib shapes are formed incurvedsurface shapes. CONSTITUTION:Protuberances 3 are formed along curved lines 4 of spiral type in the inner wall surface of the heat transfer pipe. These protuberances 3 take the shape of circular protuberances 32 in front view, or ellipse type ptoruberances 34 or ellipse curved line shaped protuberances 36 of nonsymmetry similar to the crooss section of oval shape. Also about the shape of the section surface of higher part than the base of the protuberance, it takes similar shape with of each base, and the section area is decreased comparing to the base. The shape of the section is not angular line of the acute angle shape to distinguish the side of each rib, and is formed with curved line. Since the heat transfer is accelerated by protuberances which are formed in the inner wall of the pipe and having smooth curvature, the heat transfer pipe is difficult to receive the fluid pressure, the heat transfer rate is improved by very small fluid eddys which are induced by the protuberance having anti-corrosion quality and, moreover, smooth shape. |
