Heat exchanger

A heat exchanger comprising:

• a first inlet port and a first outlet port through which first cooling medium flows;
• a second inlet port and a second outlet port through which second cooling medium flows;
• a plurality of first heat-exchanging plates, each of which is connected to the first inlet port and the first outlet port and comprises a first guide configured to define a first flow channel in which the first cooling medium is circulated, the first guide having a first through hole formed therethrough;
• and
• a plurality of second heat-exchanging plates, each of which is connected to the second inlet port and the second outlet port and comprises a second guide configured to define a second flow channel in which the second cooling medium is circulated, the second guide having a second through hole formed therethrough,
• wherein the plurality of first heat-exchanging plates and the plurality of second heat-exchanging plates are alternately layered such that one of the first guide and the second guide is inserted into another of the first guide and the second guide so as to form an overlapping structure and to define a single discharge path through the first through hole and the second through hole,
• wherein the first inlet port and the first outlet port extend through a first side of the second heat-exchanging plate and the second inlet port and the second outlet port are connected to a second side of the second heat-exchanging plate so as to communicate therewith,
• wherein the second guide extends toward the first side and the second side such that the second cooling medium, which is introduced through the second inlet port, detours along the second guide and is discharged through the second outlet port, and
• wherein the second guide extends from the second side to a center of the second heat-exchanging plate.