Heat exchanger

A heat exchanger, comprising a plurality of heat exchange plates arranged in a stacked manner, wherein

• each of the heat exchange plates comprises a base plate, a first protrusion and a second protrusion, a direction perpendicular to the base plate is defined as a first direction, both the first protrusion and the second protrusion protrude towards the first direction, a first groove is formed on a back side of the first protrusion, a second groove is formed on a back side of the second protrusion, the base plate comprises two side surfaces, a side surface facing the first direction is defined as a first side surface, and a side surface facing away from the first direction is defined as a second side surface;
• a maximum width of an orthographic projection of the first groove on a plane where the second side surface of the base plate is located is defined as λ1, a maximum width of an orthographic projection of the second groove on the plane where the second side surface of the base plate is located is defined as λ2, a depth of the first groove relative to the second side surface of the base plate is defined as Dp1, a depth of the second groove relative to the second side surface of the base plate is defined as Dp2, a thickness of a protrusion top of the first protrusion is defined as h1, a thickness of a protrusion top of the second protrusion is defined as h2, wherein −0.05 mm≤(h1+Dp1)−(h2+Dp2)≤0.05 mm, Dp1>Dp2, and λ1<λ2.