Heat exchanger and air conditioning system having the same

An air conditioning system, comprising:

• a heat exchanger, comprising:
• a first heat exchanger core comprising a plurality of heat exchange tubes, the plurality of heat exchange tubes of the first heat exchanger core comprising a plurality of first circuit heat exchange tubes for forming a first part of a first circuit;
• a second heat exchanger core located on a side of the first heat exchanger core in a thickness direction of the first heat exchanger core and comprising a plurality of heat exchange tubes, the plurality of heat exchange tubes of the second heat exchanger core comprising a plurality of first circuit heat exchange tubes for forming a second part of the first circuit, a length of the heat exchange tube of the first heat exchanger core being greater than a length of the heat exchange tube of the second heat exchanger core;
• and
• a connection part comprising a first connection part through which the plurality of first circuit heat exchange tubes of the first heat exchanger core are connected with the plurality of first circuit heat exchange tubes of the second heat exchanger core;
• wherein the plurality of heat exchange tubes of at least one of the first heat exchanger core and the second heat exchanger core further comprise a plurality of second circuit heat exchange tubes for forming a first part of a second circuit, and in the at least one of the first heat exchanger core and the second heat exchanger core, first circuit heat exchange tube groups each constituted by at least one of the plurality of first circuit heat exchange tubes and second circuit heat exchange tube groups each constituted by at least one of the plurality of second circuit heat exchange tubes are arranged alternately;
• wherein the heat exchange tube of the first heat exchanger core has a length of L1, the heat exchange tube of the second heat exchanger core has a length of L2, and ⅕<L2/L1< 9/10;
• and
• wherein the first heat exchanger core and the second heat exchanger core are arranged such that wind blows through the heat exchanger along a direction from the first heat exchanger core to the second heat exchanger core.