| 摘要 |
<p>In the present invention, at the root of fin collars there are depressions that are depressed in the direction opposite the rising direction of the fin collars. The cross-sectional shape of the depressions at the root of the fin collars is formed so as to be a circular arc that roughly follows the flange shape of a tip of the adjacent fin collar, and as a result, gaps are reduced and the contact surface area between a heat transfer pipe and the fin collars can be increased. Due to the foregoing, contact heat resistance is reduced, heat transfer between the heat transfer pipe and a heat transfer fin is improved, and heat exchange capabilities are improved.</p> |
