Plate For A Heat Exchanger And Heat Exchanger Equipped With Such Plates

The invention relates to a plate (4, 12, 14) intended to allow an exchange of heat between a first fluid and a second fluid flowing in contact with the plate (4, 12, 14), said plate (4, 12, 14) being configured to define a circuit (8) comprising a plurality of successive passageways (71, 72, 73, 74), inside which the first fluid flows in one direction of flow, changing its direction of flow from one passageway to the other, each of said passageways (71, 72, 73, 74) having a flow section for the first fluid. According to the invention, the flow section of one passageway (71, 72, 73, 74), known as the upstream passageway, is larger than the flow section of another passageway (71, 72, 73, 74), known as the downstream passageway, which is situated downstream of the upstream passageway in the direction of flow of the first fluid in the circuit (8). The invention also relates to a heat exchanger equipped with such plates.