Heat exchanger tube having fins with varying louver inclination angle

摘要

A fin for a heat exchanger includes a flat portion having an upstream flat part and a downstream flat part parallel to a flow direction of a fluid. Multiple louvers are arranged in the flow direction. A fluid-turning part including a surface approximately parallel to the flow direction is arranged between two of the multiple louvers. A first portion of the louvers located upstream of the fluid-turning part are inclined in a direction opposite from a second portion of the louvers located downstream of the fluid-turning part. The first and second portion of the louvers include first louvers and second louvers. The first louvers are inclined from the flat portion at a first inclined angle larger than a second inclined angle at which the second louvers are inclined from the flat portion. The second louvers are arranged adjacent to the fluid-turning part.