| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve efficiency of heat exchange by providing each flat fin with first and second vertical louver-type cut-and-erected portions having openings for guiding a fluid flow from one surface to the other surface thereof disposed upstream and downstream of each heat-transfer tube adding to groups of slit-type cut-and-erected portions. SOLUTION: Groups 20 of slit-type cut-and-erected portions are arranged such that slits, which are formed by cutting and bending portions of a flat fin leaving base portions 21 with a predetermined width among them and which are increased in width relative to a distance from each heat-transfer tube 2, are disposed in a radiant pattern around a respective heat-transfer tube 2. In addition, first and second louver-type cut-and-erected portions 30a and 30b are formed to project from both surfaces of a flat fin 1 by cutting predetermined portions in the flat fin 1 upstream and downstream of each heat-transfer tube 2 and slanting the both ends of the same with respect to the plane of the fin 1 at a predetermined angle. As a result, it is possible to promote the turbulence of the flow for improving heat exchanger effectiveness and efficiently performing heat exchange.</p> |
