| 摘要 |
<p>According to the present invention, in a corrugate fin type heat exchanger (2) including a core portion (2c) having a plurality of flat tubes (2a) disposed in parallel with flow direction of the air and at least one corrugate fin (2b) disposed between each pair of the flat tubes (2a), an inner thickness of the flat tube (2a) is in a range of 0.6 - 1.2 mm, a height of the corrugate fin (2b) is in a range of 3 - 6 mm, and a ratio (St/WxD) of the cross-sectional area (WxD) expressed by an overall width dimension (W) and a thickness dimension (D) of the core portion (2c) to a total cross-sectional flow passage area (St) of the plurality of flat tubes (2a) is set to a range of 0.07 - 0.24 according to the inner thickness of the flat tube (2a) and the height of the corrugate fin (2b). In this way, it is possible to reduce the Reynold's number of the flow passages within the flat tubes (2a) to keep a laminar region constantly irrespective of the variation in the hot water flow quantity, thereby reducing the variation in the water side heat transfer rate. <IMAGE></p> |
