Fin tube type heat exchanger

Abstract

A fin tube type heat exchanger includes heat transfer fins spaced apart from each other along plate thickness directions and heat transfer tubes inserted into the heat transfer fins in directions substantially orthogonal to a gas current flow direction. Each heat transfer fin includes cut and raised parts lined up from upstream to downstream on both sides of each heat transfer tube. The cut and raised parts are inclined with respect to the gas current flow direction to guide gas current to a rear side of the heat transfer tubes. A height of each of the cut and raised parts increases gradually toward the downstream side. A value calculated by dividing an average height of each cut and raised part by a fin pitch is greater than 0.3 and less than 0.6. The fin pitch is a spacing between the heat transfer fins.

1 . A fin tube type heat exchanger, comprising:
 a plurality of heat transfer fins lined up such that the heat transfer fins are spaced apart from each other along plate thickness directions of the heat transfer fins, the heat transfer fins being configured to be disposed in a gas current; and   a plurality of heat transfer tubes inserted into the plurality of heat transfer fins and being disposed in directions substantially orthogonal to a gas current flow direction,   each of the heat transfer fins including a plurality of cut and raised parts lined up from an upstream side to a downstream side in the gas current flow direction, the cut and raised parts being formed by a cutting and raising fabrication process on both sides of each of the heat transfer tubes,   the plurality of cut and raised parts being inclined with respect to the gas current flow direction such that the gas current in a vicinity of each of the heat transfer tubes is guided to a rear side in the gas current flow direction of that heat transfer tube;   a height of each of the cut and raised parts with respect to a heat transfer fin surface from which the cut and raised part extends increasing gradually toward the downstream side in the gas current flow direction, and   a value calculated by dividing an average height of each cut and raised part by a fin pitch is greater than 0.3 and less than 0.6, the fin pitch being a spacing between the heat transfer fins, and the average height each cut and raised part being an average of a front end height and a rear end height thereof.   
     
     
         2 . The fin tube type heat exchanger according to  claim 1 , wherein
 an inclination angle formed between a ridge of each of the cut and raised parts and the heat transfer fin surface from which the cut and raised part extends is less than 30°.   
     
     
         3 . The fin tube type heat exchanger according to  claim 1 , wherein
 the plurality of cut and raised parts are disposed such that their average heights sequentially increase at a greater rate in the cut and raised parts on the downstream side in the gas current flow direction than in the cut and raised parts on the upstream side in the gas current flow direction.   
     
     
         4 . The fin tube type heat exchanger according to  claim 2 , wherein
 the plurality of cut and raised parts are disposed such that their average heights sequentially increase at a greater rate in the cut and raised parts on the downstream side in the gas current flow direction than in the cut and raised parts on the upstream side in the gas current flow direction.