Heat exchanger for a motor vehicle

Abstract

An exhaust gas heat exchanger for a motor vehicle may include an outer tube extending along a longitudinal direction to be flowed-through by a hot gas. The outer tube may define an outer tube interior space and in a cross section perpendicular to the longitudinal direction may include at least two outer tube-tube walls. An inner tube may be arranged in the outer tube interior space and may extend along the longitudinal direction. A longitudinal end of the inner tube may be closed and may define an inner tube interior space and in the cross section perpendicular to the longitudinal direction, may include at least two inner tube-tube walls at least one of which may include a plurality of apertures. A plurality of thermoelectric modules may be arranged on an outside of the at least two outer tube-tube walls and may each include a hot side and a cold side.

1 . An exhaust gas heat exchanger for a motor vehicle comprising:
 an outer tube extending along a longitudinal direction configured to be flowed-through by a hot gas, the outer tube defining an outer tube interior space and in a cross section perpendicular to the longitudinal direction, comprises at least two outer tube-tube walls,   an inner tube arranged in the outer tube interior space extending along the longitudinal direction, wherein a longitudinal end of the inner tube is closed and defines an inner tube interior space and in the cross section perpendicular to the longitudinal direction, comprises at least two inner tube-tube walls,   wherein at least one of the at least two inner tube-tube walls includes a plurality of apertures, wherein the inner tube interior space fluidically communicates with the outer tube interior space via the plurality of apertures,   wherein a plurality of thermoelectric modules are arranged on an outside of the at least two outer tube-tube walls and each include a hot side facing the outer tube and a cold side facing away from the outer tube,   wherein at least one coolant tube configured to be flowed-through by a coolant is arranged on the cold side of at least one of the plurality of thermoelectric modules,   wherein an inside of at least one of the at least two outer tube-tube walls includes at least one surface area-enlarging structure.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein the at least one surface area-enlarging structure, with respect to the longitudinal direction, is disposed in a region of at least one of the plurality of thermoelectric modules. 
     
     
         3 . The heat exchanger according to  claim 1 , wherein the at least one surface area-enlarging structure is disposed opposite at least one aperture of the plurality of apertures, so that the hot gas exiting the at least one aperture at least partly strikes the at least one surface area-enlarging structure. 
     
     
         4 . The heat exchanger according to  claim 1 , wherein the at least one surface area-enlarging structure projects from at least one of the at least two outer tube-tube walls away towards the inner tube and is integrally moulded on the outer tube. 
     
     
         5 . The heat exchanger according to  claim 1 , wherein the at least one surface area-enlarging structure comprises a plurality of protrusions projecting away from the at least one outer tube-tube wall towards the inner tube. 
     
     
         6 . The heat exchanger according to  claim 5 , wherein the plurality of protrusions comprise a plurality of webs extending along an extension direction spaced from one another to define a plurality of intermediate spaces. 
     
     
         7 . The heat exchanger according to  claim 5 , wherein one of the plurality of protrusions or the plurality of webs, in a top view of the at least two outer tube-tube walls, extend along an extension direction at least one of linearly and non-linearly at least in sections. 
     
     
         8 . The heat exchanger according to  claim 5 , wherein one of the plurality of protrusions or the plurality of webs comprise a wave-like geometry in a top view. 
     
     
         9 . The heat exchanger according to  claim 5 , wherein
 a plurality of webs form a web group, and   the plurality of webs of the web group radially extend away from a virtual centre point defined on at least one of the at least two outer tube-tube walls.   
     
     
         10 . The heat exchanger according to  claim 9 , wherein on at least one of the at least two outer tube-tube walls a plurality of web groups are arranged grid-like with at least two grid columns and with at least two grid lines. 
     
     
         11 . The heat exchanger according to  claim 5 , wherein at least one of the plurality of protrusions or the plurality of webs are arranged parallel to one another. 
     
     
         12 . The heat exchanger according to  claim 6 , wherein at least one of the plurality of protrusions or the plurality of webs along the extension direction each have a plurality of interruptions, the plurality of interruptions each fluidically interconnecting two adjacent intermediate spaces. 
     
     
         13 . The heat exchanger according to  claim 12 , wherein the plurality of interruptions of one of the adjacent plurality of protrusions or the plurality of webs along the extension direction are staggered relative to one another so that through the plurality of interruptions arranged staggered, a plurality of communication channels are defined and fluidically interconnect a plurality of adjacent intermediate spaces between one of the plurality of protrusions or the plurality of webs. 
     
     
         14 . The heat exchanger according to  claim 13 , wherein the plurality of communication channels extend along a channel direction, the channel direction forming an acute angle with the extension direction of one of the plurality of protrusions or the plurality of webs. 
     
     
         15 . The heat exchanger according to  claim 5 , wherein at least one web of the plurality of webs includes an aperture fluidically interconnecting two adjacent intermediate spaces of the plurality of intermediate spaces. 
     
     
         16 . The heat exchanger according to  claim 1 , wherein the at least one surface area-enlarging structure comprises at least one of a plurality of dimpled protrusions and a plurality of dimpled recesses arranged grid-like on an inside of at least one of the at least two outer tube-tube walls. 
     
     
         17 . The heat exchanger according to  claim 16 , wherein the grid-like arrangement comprises at least two grid columns, wherein adjacent grid columns are alternately formed by one of the plurality of protrusions or the plurality of recesses. 
     
     
         18 . The heat exchanger according to  claim 16 , wherein at least one of the plurality of protrusions and the plurality of recesses comprise a round, circular geometry in a top view of one of the at least two outer tube-tube walls. 
     
     
         19 . The heat exchanger according to  claim 16 , wherein at least one projection of the plurality of projections and at least one recess of the plurality of recesses tapers, conically, away from at least one of the at least two outer tube-tube walls. 
     
     
         20 . The heat exchanger according to  claim 16 , wherein one of:
 at least one of the at least two outer tube-tube walls with the at least one surface area-enlarging structure is; or   at least one of the at least two outer tube-tube walls with the at least one surface area-enlarging structure comprises at least one first flat wall section that merges into a second flat wall section, arranged at an obtuse angle to the first wall section).   
     
     
         21 . A heat exchanger arrangement, comprising:
 at least two heat exchangers arranged on top of one another, and stacked onto one another, wherein the at least two heat exchangers fluidically communicate with one another via at least one common gas outlet configured to discharging a hot gas from the heat exchange arrangement.   
     
     
         22 . A motor vehicle comprising:
 an internal combustion engine including an exhaust system;   
       a heat exchanger interacting with the exhaust system, the heat exchanger comprising one of: 
       an outer tube extending along a longitudinal direction configured to be flowed-through by a hot gas, the outer tube defining an outer tube interior space and in a cross section perpendicular to the longitudinal direction, comprises at least two outer tube-tube walls, an inner tube arranged in the outer tube interior space extending along the longitudinal direction, wherein a longitudinal end of the inner tube is closed and defines an inner tube interior space and in the cross section perpendicular to the longitudinal direction, comprises at least two inner tube-tube walls, wherein at least one of the at least two inner tube-tube walls includes a plurality of apertures, wherein the inner tube interior space fluidically communicates with the outer tube interior space via the plurality of apertures, wherein a plurality of thermoelectric modules are arranged on an outside of the at least two outer tube-tube walls and each include a hot side facing the outer tube and a cold side facing away from the outer tube, wherein at least one coolant tube configured to be flowed-through by a coolant is arranged on the cold side of at least one of the plurality of thermoelectric modules, wherein an inside of at least one of the at least two outer tube-tube walls includes at least one surface area-enlarging structure; or at least two heat exchangers arranged on top of one another and stacked onto one another, wherein the at least two heat exchangers fluidically communicate with one another via at least one common gas outlet configured to discharging a hot gas from the heat exchange arrangement.