| 摘要 |
PURPOSE:To improve the heat transfer efficiency of the captioned heat transfer pipe and to reduce a pressure loss by a method wherein a V-shaped spiral groove is formed on the inner surface of a smooth pipe to thereby produce the heat transfer pipe with the depth of the groove being 0.02-0.2mm. and the pitch thereof being 0.1-0.5mm. CONSTITUTION:In an arrangement in which a fluid varying in phase is flowed within the pipe 1 in a double phase condition by means of a pump (not shown), the V-shaped spiral groove 2 is formed on the smooth inner wall surface of the pipe 1. In this case, the depth (h) of the groove 2 is made to be in the order of 0.02-0.2mm. and pitch (p) thereof is made to be in order of 0.1-0.5mm.. Consequently, when the liquid is boiling, it becomes itself a film over the entire grooved inner wall surface of the pipe while it is subjected to a rotary force along the surface so that the thin groove 2 acts as a boiling nucleus to thereby increase the heat transfer efficiency of the pipe. Further, as the groove 2 is made smooth by being covered with the liquid, the loss of pressure of the liquid is reduced. |
