Heat exchanger and air conditioner including the same

An air conditioner comprising:

• a compressor;
• an indoor heat exchanger;
• an outdoor heat exchanger;
• a subcooler;
• and
• an expansion valve,
• wherein at least one of the indoor heat exchanger, the outdoor heat exchanger, and the subcooler includes:
• an inner tube including:
• a plurality of bending portions bent with a preset curvature, each bending portion of the plurality of bending portions having a first end and a second end,
• a plurality of first heat exchange portions extending respectively from the first end of each bending portion of the plurality of bending portions, and
• a plurality of second heat exchange portions extending respectively from the second end of each bending portion of the plurality of bending portions;
• a plurality of outer tubes each having the first heat exchange portion or the second heat exchange portion extending from one bending portion of the plurality of bending portion extending therethrough so as to form a first double-tube structure with boundary at an outer circumferential surface of the first heat exchange portion or the second heat exchange portion extending through the respective outer tube, each outer tube of the plurality of outer tubes including at least one through hole at an outer circumferential surface thereof;
• a plurality of connection tubes respectively connecting facing pairs of through holes of the at least one through hole included in a pair of outer tubes of the plurality of outer tubes that surround the first heat exchange portion and the second heat exchange portion of a same bending portion of the plurality of bending portions,
• wherein the at least one of the indoor heat exchanger, the outdoor heat exchanger, and the subcooler is configured so that:
• a first connection tube connects a first outer tube of the plurality of outer tubes to a second outer tube of the plurality of outer tubes,
• a second connection tube connects the second outer tube to a third outer tube of the plurality of outer tubes,
• a third connection tube connects the third outer tube to a fourth outer tube of the plurality of outer tubes,
• a first plane on which the first outer tube and the second outer tube are positioned in parallel is not parallel to a second plane on which the second outer tube and the third outer tube are positioned in parallel,
• the second plane is not parallel with a third plane on which the third outer tube and the fourth outer tube are positioned in parallel,
• an angle formed by the first plane and the second plane is different from an angle formed by the second plane and the third plane,
• a first refrigerant is flowable respectively through the first heat exchange portions, then the bending portions, and then the second heat exchange portions of the inner tube,
• a second refrigerant is flowable through the first outer tube, then through the first connection tube, then through the second outer tube, then through the second connection tube, then through the third outer tube, then through the third connection tube, and then through the fourth outer tube, and
• the second refrigerant exchanges heat with the first refrigerant at the first boundary inside the respective outer tubes of the plurality of outer tubes.