HEAT EXCHANGE APPARATUS
Provided is a heat exchanger capable of performing heat exchange between a refrigerant and air continuously even if frost forms thereon. A heat exchanger ( 1 ) that exchanges heat between a refrigerant and air includes: a plurality of heat transfer tubes ( 3 ) extending in an internal flow direction in which the refrigerant flows; and a corrugated member ( 4 ) having a corrugated shape. The corrugated member ( 4 ) includes: fins ( 5 ) that are arranged at at least two different pitches, a relatively large first pitch (P1) and a relatively small second pitch (P2), in the internal flow direction; and folded portions ( 6 ) that are bonded alternately in the internal flow direction to the heat transfer tubes ( 3 ) that are adjacent to each other.
1 . A heat exchanger that exchanges heat between a refrigerant and air, comprising:
a plurality of heat transfer tubes extending in an internal flow direction in which the refrigerant flows; and
a corrugated member having a corrugated shape, comprising: a plurality of fins that are arranged at at least two different pitches, a relatively large first pitch and a relatively small second pitch, in the internal flow direction; and a plurality of folded portions that are bonded alternately in the internal flow direction to the heat transfer tubes that are adjacent to each other.
2 . The heat exchanger according to claim 1 , wherein
each of the fins comprises a plurality of flat portions that are arranged in a staggered or stepped manner in an external flow direction perpendicular to the internal flow direction and a direction in which the heat transfer tubes are arranged, and
slits opening in the external flow direction are formed between the flat portions.
3 . The heat exchanger according to claim 2 , wherein the fins are arranged in such a manner that the fins coincide with each other by parallel displacement in the internal flow direction.
4 . The heat exchanger according to claim 2 , wherein widths of the flat portions are equal in the external flow direction.
5 . The heat exchanger according to claim 2 , wherein the flat portions are first flat portions and second flat portions that are arranged in a staggered manner in the external flow direction.
6 . The heat exchanger according to claim 5 , wherein the slits are formed between the first flat portions and the second flat portions, and a dimension of each of the slits in the internal flow direction is one half or less of the second pitch.
7 . The heat exchanger according to claim 2 , wherein the flat portions form a series of steps descending in a direction inclined with respect to the external flow direction and the internal flow direction.
8 . The heat exchanger according to claim 1 , wherein the fins are arranged so that the second pitch appears before and after the first pitch.
9 . The heat exchanger according to claim 1 , wherein the first pitch and the second pitch appear alternately.
10 . The heat exchanger according to claim 1 , wherein when an odd number of the fins are arranged in series from above in the internal flow direction, and odd-numbered fins are defined as first fins and even-numbered fins are defined as second fins, a total sum of the pitches between the first fins and the fins adjacent to and below the first fins is equal to a total sum of the pitches between the second fins and the fins adjacent to and below the second fins.
11 . The heat exchanger according to claim 1 , wherein the first pitch is 1.2 times or more and 3.0 times or less the second pitch.
12 . The heat exchanger according to claim 1 , wherein
the plurality of heat transfer tubes comprises at least four of the heat transfer tubes, and
a pair of the corrugated members having the same shape are bonded to both sides of each of the heat transfer tubes interposed between the two adjacent heat transfer tubes in such a manner that the corrugated members coincide with each other by parallel displacement in an arbitrary direction.
13 . The heat exchanger according to claim 1 , wherein the adjacent heat transfer tubes are flat tubes that are parallel to each other.