| 摘要 |
The fin tube-type heat exchanger (1A) includes a plurality of fins (2) arranged in parallel, and a refrigerant flow passage (10). The refrigerant flow passage (10) comprises a main flow passage (6), a plurality of branch flow passages (7), and a header (3). Each branch flow passage (7) includes at least three hairpin pipes (4) and a plurality of return bend pipes (5), and passes through a fin (2). The plurality of return bend pipes (5) in each of the plurality of branch flow passages (7) includes at least one smooth bend pipe (52) having a smooth inner peripheral surface, and at least one grooved bend pipe (51) having a plurality of helical grooves formed in the inner peripheral surface. At least one smooth bend pipe (52) is positioned closest to the header (3) when following the branch flow passage (7) from the header (3). |
