Heat exchanger and thermal management system

A heat exchanger, comprising a hot collecting inlet channel, a plurality of hot fluid channel layers and a hot collecting outlet channel sequentially connected and in communication with each other;

• the heat exchanger further comprises a cold collecting inlet channel, a plurality of cold fluid channel layers and a cold collecting outlet channel sequentially connected and in communication with each other, wherein the plurality of hot fluid channel layers and the plurality of cold fluid channel layers are alternately stacked;
• the heat exchanger further comprises a flow guide plate, which is disposed in the plurality of cold fluid channel layers, the flow guide plate is provided with a plurality of first flow guide grooves connected and in communication with the cold collecting inlet channel and the cold collecting outlet channel, the plurality of first flow guide grooves are spaced from each other, forming a plurality of flow diverting gaps, such that a cold fluid in the plurality of cold fluid channel layers is capable of flowing from the cold collecting inlet channel to the cold collecting outlet channel along both the plurality of first flow guide grooves and the plurality of flow diverting gaps;
• and
• each of the plurality of first flow guide grooves is formed by one of a straight groove section and a curved groove section individually or is formed by alternately arranging both a straight groove section and a curved groove section, a side wall of the curved groove section is in a smoothly curved shape, and a center line of the straight groove section is in a linear shape, the straight groove section comprises a plurality of staggered passages communicated with each other in sequence along a center line of the straight groove section and adjacent two of the plurality of staggered passages are distributed in a staggered manner along a direction perpendicular to the center line of the straight groove section, such that each of the plurality of staggered passages is capable of being in communication with adjacent one of the plurality of staggered passages and corresponding one of the plurality of flow diverting gaps on a side of the straight groove section.