Patent ID: 8245767

Claim:
A heat transmission unit for use in an internal combustion engine to cool exhaust gases, wherein the heat transmission unit comprises: (a) a first channel conducting a first fluid to be cooled and provided with a first inlet and a first outlet; and (b) a second channel conducting a cooling second fluid and provided with a second inlet and a second outlet, wherein the first channel for conducting the first fluid to be cooled and the second channel for conducting the cooling second fluid are separated from each other by at least one partition wall provided with a plurality of first ribs and second ribs extending from the at least one partition wall into the first channel conducting the first fluid to be cooled, wherein a cross-sectional area, between the at least one partition wall and a central wall delimiting the first channel conveying the first fluid to be cooled, is larger throughout a first fluid-conveying portion than in a second fluid-conveying portion, wherein the first ribs are distributed along a length of the first channel so that an effective flow-conducting first cross section is smaller in the first fluid-conveying portion than an effective flow-conducting second cross section in the second fluid-conveying portion, or is equal thereto.