Heat exchanger and corrugated fin
A heat exchanger includes tubes arranged in one direction, and a corrugated fin provided between the tubes. The corrugated fin includes joints joined to the tubes, and fin bodies that connect the joints which are located next to each other along the wave shape. The fin body includes a cut-raised portion that has a shape in which a part of the fin body is cut and raised for promotion of heat transfer. The cut-raised portion includes a cut-raised end on at least one end of the cut-raised portion in the one direction. The cut-raised end has recesses and projections on its surface that increase hydrophilicity of the surface of the cut-raised end.
1. A heat exchanger that performs heat exchange between a first fluid and a second fluid, the heat exchanger comprising:
tubes which are arranged in one direction and in which the first fluid flows; and
a corrugated fin provided between the tubes, curved to have a wave shape, and configured to promote heat exchange between the first fluid and the second fluid, the second fluid flowing between the tubes, wherein
the corrugated fin includes joints that are joined to the tubes, and fin bodies that are each between and connect the joints which are located next to each other along the wave shape,
the fin body includes a cut-raised portion that has a shape in which a part of the fin body is cut and raised for promotion of heat transfer,
the cut-raised portion includes a cut-raised body that guides the second fluid, and a cut-raised end that is provided on at least one end of the cut-raised portion in the one direction and has a plate shape extending from the cut-raised body,
the cut-raised end has recesses and projections that increase hydrophilicity of a surface of the cut-raised end on at least one side of the cut-raised end in a thickness direction of the cut-raised end,
the recesses and projections of the cut-raised end are configured to promote drainage of water toward the joint or a surface of the tube,
the fin body includes curved connections curved and connected to the joints at opposite ends of the fin body in the one direction,
the fin body includes a cut-raised gap that is provided adjacent to the cut-raised portion by formation of the cut and raised shape of the cut-raised portion,
at least one of the curved connections has a notch extending from the cut-raised gap, and
the notch extends outward of a range of the cut-raised portion in the one direction.
2. The heat exchanger according to claim 1 , wherein
the curved connections each includes recesses and projections that increase hydrophilicity of a surface of the curved connection on at least one side of the curved connection in a thickness direction of the curved connection.
3. The heat exchanger according to claim 2 , wherein
the cut-raised end provided on at least one end of the cut-raised portion in the one direction includes one cut-raised end that is provided at an end of the cut-raised portion on one side of the cut-raised portion in the one direction,
the recesses and projections of the one cut-raised end includes a plurality of grooves, and the recesses and projections of one of the curved connections closer to the one cut-raised end also includes a plurality of grooves, and
at least one of the plurality of grooves of the one cut-raised end is connected to at least one of the plurality of grooves of the one of the curved connections.
4. The heat exchanger according to claim 1 , wherein the second fluid is a gas that generates condensed water by heat exchange with the first fluid.
5. The heat exchanger according to claim 1 , being provided in an environment to be exposed to water.
6. The heat exchanger according to claim 1 , wherein the tubes extend in a vertical direction.
7. The heat exchanger according to claim 1 , wherein a depth of a recess included in the recesses and projections is 10 μm or deeper.
8. The heat exchanger according to claim 1 , wherein the recesses and projections of the cut-raised end are provided on each of opposite sides of the cut-raised end in the thickness direction.
9. The heat exchanger according to claim 1 , wherein the cut-raised portion for promoting heat transfer is a louver.
10. A corrugated fin for a heat exchanger performing heat exchange between a first fluid and a second fluid, the corrugated fin being disposed between tubes arranged in one direction, being curved to form a wave shape, and promoting the heat exchange between the first fluid flowing through the tubes and the second fluid flowing between the tubes,
the corrugated fin comprising:
joints joined to the tubes; and
fin bodies that are each between and connect the joints which are located next to each other along the wave shape, wherein
the fin body includes a cut-raised portion that has a shape in which a part of the fin body is cut and raised for promotion of heat transfer,
the cut-raised portion includes a cut-raised body that guides the second fluid, and a cut-raised end that is provided on at least one end of the cut-raised portion in the one direction and has a plate shape extending from the cut-raised body,
the cut-raised end has recesses and projections that increase hydrophilicity of a surface of the cut-raised end on at least one side of the cut-raised end in a thickness direction of the cut-raised end,
the recesses and projections of the cut-raised end are configured to promote drainage of water toward the joint or a surface of the tube,
the fin body includes curved connections curved and connected to the joints at opposite ends of the fin body in the one direction,
the fin body includes a cut-raised gap that is provided adjacent to the cut-raised portion by formation of the cut and raised shape of the cut-raised portion,
at least one of the curved connections has a notch extending from the cut-raised gap, and
the notch extends outward of a range of the cut-raised portion in the one direction.