| 摘要 |
PROBLEM TO BE SOLVED: To provide a water heat exchanger in which heat transfer performance is improved between water and a refrigerant.SOLUTION: A water heat exchanger includes a flat pipe 20 having a rectangular cross section and a flat perforated pipe. The flat perforated pipe contacts with the flat pipe 20 at a long side of the rectangular cross section. Multiple first dimples 22a, each of which has a square pyramid shape, are formed at the flat pipe 20. Each first dimple 22a is formed so that a plane apex of the first dimple 22a faces the upstream side and the downstream side of water flow. |
