Abstract: A heat exchanger, includes modules defining a first path for a first fluid, each having two metal sheets forming between them a network of channels which are located in parallel with each other from the fluidic point of view, each channel interposed between two neighbouring channels of the network being, over the whole of its developed length, adjacent to these two neighbouring channels from which it is isolated by two respective weld lines connecting the two metal sheets; a second path for a second fluid is defined between the modules; and an overall variation in the passage cross-section over the length of at least one of the paths with continuity of profiles of the channels.

Abstract: A heat exchange module is disclosed comprising two metal sheets welded along weld lines defining between them a group of channels disposed side by side substantially in a common plane, intended to be passed through by an exchange fluid and, from the fluidic point of view, being in parallel with each other between two connection orifices of the module. The group of channels has a generally U-shape configuration, which connects together the said connection orifices that are laterally separated from each other.