| 摘要 |
PURPOSE:To promote the heat transfer function and to improve the function at the time of frosting by providing on fins a corrugated portion in which ceset portions and root portions are alternately formed in a concentric manner around the fulcrum of a heat transfer pipe and a corrugated portion in which crest portions and root portions are alternately formed rectangularly to the air current flowing direction. CONSTITUTION:Heat transfer pipes 10 are inserted into fins 9 at a predetermined interval, and corrugated portions 15 and 16 in which crest portions and root portions are alternately formed, are provided on the fins 9. An air current 17 coming into collision with the heat transfer pipes 10 assumes a horseshoe hoof shaped vortex 18, and flows along the heat transfer pipe 10 by the corrugated portion 15 and the dead water zone of the heat transfer pipe 10 and the heat trnasfer is promoted. Furthermore, when an air current 18 flows along the corrugated portion 16, a vortex 19 is generated to remarkably promote the heat transfer between heat transfer pipes 10. Next, the vortex 19 flows along the corrugated portion 16 into the downstream part of the heat transfer pipe 10, and interface with the horseshoe shaped vortex 18, thus producing the rotary mixing 20 of an extremely strong flow. Furthermore, the dead water zone is reduced to increase an effective heat transfer surface area and a turbulent flow promoting effect is expected and the heat transfer is greatly improved and the frosting quantity per unit time is increased. |
