| 摘要 |
PURPOSE:To improve heat transfer performance by a method wherein slit-type cut-ups are provided on a flat plate fin in gaps in the gravitational direction of heat transfer tubes between the outer diameters of the same tubes excluding the spaces on the center lines of gravitational direction between the heat trans fer tubes while the legs of all cut-ups are formed so as to be reversed trancated chevron type with respect to the direction of air stream. CONSTITUTION:The flat fins 6 are arranged in parallel to a direction orthogonal to the direction of air stream and fin collars 7 are formed on the flat fins 6 by burrying process. The heat transfer tubes 8 are penetrated orthogonally to the flat plate fins 6 and are arranged so as to be checkerboard pattern in parallel to the direction 9 of air stream. The relation of 1.2D<=L<=1.4D is satis fied when the pitch of tubes in the air stream direction is shown by L and the outer diameter of the heat transfer tube is shown by D. The slit-type cut-ups 10, 11 are provided on the flat plate fins 6 alternately on the front and rear surfaces thereof only in the gaps in the gravitational direction between the heat transfer tubes 6 and all of the legs 12 of the cut-ups are formed so as to be reversed trancated chevron type with respect to the air stream direction 9 regardless of the provided positions of the legs 12. |
