The invention relates to a cooler having means for directing a cooling medium, means for directing a medium to be cooled, and an essentially axially symmetrical housing. The invention also relates to a method of cooling a medium, in which a cooling medium and a medium to be cooled are directed in an essentially axially symmetrical housing.
Coolers of the generic type and methods of the generic type are used, for example, for the charge-air pre-cooling of an exhaust-gas turbocharger. Such charge-air coolers serve to cool the air compressed by the turbocharger before entry into the engine of a motor vehicle. There are a multiplicity of different embodiments of such coolers, which differ greatly with regard to numerous features. For example, cascade-shaped coolers are known, or also coolers having an axially symmetrical housing, the latter being designed, for example, as tube-nest coolers.
In the different embodiments, different problems occur, in particular in connection with the aim of increasing the cooling capacity. For example, if it is desired to increase the cooling capacity in a surface cooler, this can be achieved by enlarging the cooler perpendicularly to the flow direction of the medium to be cooled. However, the cooler thus requires an enlarged construction space, a factor which is a disadvantage in principle. In a round cooler, such as a tube-nest cooler, for example, the cooling capacity can be increased by the cooler being enlarged in the axial direction. A disadvantage with this solution, however, is that an increased pressure drop occurs inside the cooler.