| 摘要 |
<p>A fin and tube heat exchanger including a plurality of parallely arranged heat transfer tubes 10 and a plurality of plate-shaped fins 1 provided orthogonally to the heat transfer tubes 10, each of the heat transfer tubes being in contact with fin collars of the plate-shaped fins, and being inserted along the fin collars. Each fin collar 2 is configured such that a bend is provided in each of a re-flared portion 3 and in a root portion 4 of the fin collar 2 and a flat intermediate portion 5 is formed between the bends. A thickness Tw1 of the re-flared portion 3 is smaller than a thickness Tw2 of the root portion 4. A radius R1 of the bend of the re-flared portion 3 is larger than a radius R2 of the bend of the root portion 4, and a ratio (Tw1/R1) of the radius R1 and the thickness Tw1 of the bend of the re-flared portion 3 is one half or more of a ratio (Tw2/R2) of the radius R2 and the thickness Tw2 of the bend of the root portion 4.</p> |
