Heat exchanger with a circumferential seal

The present invention relates to a heat exchanger (1) with a base (2), a seal (3) and a cover (4), - wherein the base (2) has two accommodation grooves (5, 5') which each have a groove bottom (7, 7'), - wherein an intermediate region (10) is formed in the plane between two passages (8), - wherein a ramp (11) runs between the intermediate region (10) and the groove bottoms (7, 7'). It is thereby essential according to the invention that - the seal (3) runs in the accommodation grooves (5, 5') and with a sealing web (12) across two ramps (11) and an intermediate region (10) lying therebetween, - each ramp (11) is rounded at the transition to the accommodation groove (5, 5') with a radius (R1) and at the transition to the intermediate region (10) with a radius (R2), - the ramps (11) are inclined between 20 DEG and 60 DEG with respect to the intermediate region (10), or have an S-shaped progression, wherein a reversal point (W) is arranged in the region from 10% to 80% of the height difference (h) starting from t