| 摘要 |
PURPOSE:To improve simultaneously the evaporation characteristic and condensation heat conductivity characteristic by one heat transfer pipe used for heat exchangers and make it possible to improve the mass productivity by forming a projecting section which has a void at least on one of the wall face in a pipe and wall face on the outside of the pipe and providing a mixture of the projecting sections and flat sections on the wall face. CONSTITUTION:A heat transfer pipe 10 has a projecting section 12 which is formed by a porous material layer which is provided on the inner wall face 11a of a circular pipe 11 in a lamination made by the adhesion of the sintering of a metal in the aluminium family or by the coating of a resin in flurorine family or metallic thin film or by other ways. A plurality of projection sections 12 are provided to form annular groups of them circumferentially with a distance P between axially adjoining groups of the pipe 11. Foaming is promoted from the positions where the projecting sections 12 consisting of the porous material layer of the heat transfer pipe 10 are formed, making the heat transfer characteristic of the heat transfer pipe 10 extremely good. The heat transfer characteristic at the spot where the projecting section 12 of the porous material layer is not formed is somewhat inferior, but it is not to a large extent. Further, the condensation heat conduction coefficient at the flat sections 15 of the inner wall face 11a on the heat transfer pipe 10 is improved because the condensation liquid film 14 between adjoining sections 12 is pulled to the projecting sections by their capillary action and it becomes thereby thinner.
|
