Flow channel for a heat exchanger, and heat exchanger comprising such flow channels

Abstract

The invention relates to a flow channel of a heat exchanger with two parallel heat transfer areas that are arranged at a distance corresponding to a channel height 11. Each heat transfer area (F 1 , F 2 ) is provided with a structure that is formed by a plurality of structural elements which are placed next to each other in rows running perpendicular to the direction of flow P and extend into the flow channel. Each structural element has awidth B, a length L, a height h, a flow-off angle a, and an overlap U while being provided with a longitudinal axis.

1 . A flow passage through which a medium can flow in a direction of flow P, of a heat exchanger having two heat exchanger surfaces which lie substantially opposite one another, are in particular arranged parallel and/or at a spacing of a passage height H and each have a structure formed from a multiplicity of structure elements that are arranged next to one another in rows transversely with respect to the direction of flow P and project into the flow passage, the structure elements each having a width B, a length L, a height h, a flow-off angle α and a longitudinal axis, wherein at least two rows comprising structure elements on substantially opposite heat exchanger surfaces have an overlap with one another.  
   
   
       2 . The flow passage as claimed in  claim 1 , wherein the overlap is 100%.  
   
   
       3 . The flow passage as claimed in  claim 1 , at least one structure element is elongate, in particular rectangular in form and has a straight longitudinal axis.  
   
   
       4 . The flow passage as claimed in  claim 1 , wherein at least one structure element is elongate and angled in form and has an angled longitudinal axis which forms the flow-off angle α and a flow-on angle β with the direction of flow P.  
   
   
       5 . The flow passage as claimed in  claim 1 , wherein at least one structure element is arcuate in form and has a longitudinal axis which is curved with a radius R and forms the flow-off angle (α) and a flow-on angle β with the direction of flow P.  
   
   
       6 . The flow passage as claimed in  claim 1 , wherein at least one structure element is approximately Z-shaped in form and has a doubly curved longitudinal axis with radii which forms the flow-off angle α and a flow-on angle β with the direction of flow P.  
   
   
       7 . The flow passage as claimed in  claim 1 , at least one structure element is V-shaped in form and has straight V limbs.  
   
   
       8 . The flow passage as claimed in  claim 1 , wherein at least one structure element is V-shaped in form and has V limbs which are curved away from the direction of flow.  
   
   
       9 . The flow passage as claimed in  claim 1 , wherein the height h of at least one of the structure elements is 20% to 50% of the passage height H.  
   
   
       10 . The flow passage as claimed in  claim 9 , wherein the length L of at least one structure element is from two to twelve times the height h of the structure element.  
   
   
       11 . The flow passage as claimed in  claim 1 , wherein the distance s between the rows amounts to 0.5 to eight times the depth T.  
   
   
       12 . The flow passage as claimed in  claim 1 , wherein the distance s between in each case two rows varies in the direction of flow P.  
   
   
       13 . The flow passage as claimed in  claim 1 , wherein at least one structure element has a constant width B in the range from 0.1 to 6.0 mm, preferably in the range from 0.1 to 3.0 mm.  
   
   
       14 . The flow passage as claimed in  claim 1 , wherein at least one structure element has a width which increases in the direction of flow between a starting width B 1  and a finishing width B 2 , the starting width B 1  being in the range from 0.1 to 4 mm and the finishing width B 2  being in the range from 0.1 to 6 mm.  
   
   
       15 . The flow passage as claimed in  claim 1 , wherein the flow-off angle α is in the range from 20 to 70°, preferably in the range from 40 to 65°, and in particular has a value of from 50 to 60°.  
   
   
       16 . The flow passage as claimed in  claim 4 , wherein the flow-on angle β is in each case larger than the flow-off angle α.  
   
   
       17 . The flow passage as claimed in  claim 6 , wherein the radius R is in the range from 1 to 10 mm, preferably in the range from 1 to 5 mm.  
   
   
       18 . The flow passage as claimed in  claim 5 , wherein the radii R 1  and R 2  are equal to the radius R.  
   
   
       19 . The flow passage as claimed in  claim 1 , wherein a row in each case has identical structure elements.  
   
   
       20 . The flow passage as claimed in  claim 1 , wherein a row in each case has different structure elements.  
   
   
       21 . The flow passage as claimed in  claim 19 , wherein individual structure elements are arranged next to one another in pairs at a distance a and in mirror-image fashion with respect to one another.  
   
   
       22 . The flow passage as claimed in  claim 19 , wherein some or all the structure elements are parallel but offset with respect to one another and are arranged in pairs at a distance a transversely with respect to the direction of flow.  
   
   
       23 . The flow passage as claimed in  claim 21 , wherein a distance a between two structure elements may vary within at least one row.  
   
   
       24 . The flow passage as claimed in  claim 21 , wherein the distance a is in the range from 0 to 8 mm.  
   
   
       25 . The flow passage as claimed in  claim 19 , wherein individual structure elements of a row are offset by an amount f with respect to one another in the direction of flow P, the amount f being less than the depth T of the structure elements and T being the projection of the length L transversely with respect to the direction of flow P.  
   
   
       26 . The flow passage as claimed in  claim 22 , wherein individual structure elements of a row are not arranged parallel and have a differing flow-off angle α.  
   
   
       27 . The flow passage as claimed in  claim 22 , wherein individual structure elements of a row have different lengths L 1 , L 2 .  
   
   
       28 . The flow passage as claimed in  claim 1 , wherein opposite rows have an offset f in the direction of flow P, f being less than the depth T of a row.  
   
   
       29 . The flow passage as claimed in  claim 1 , wherein some or all the structure elements of rows lying opposite one another are oppositely oriented, in particular have an opposite flow-off angle α.  
   
   
       30 . The flow passage as claimed in  claim 1 , wherein the rows lying opposite one another have voids between the structure elements with structure elements of the other row in each case lying opposite these voids.  
   
   
       31 . The flow passage as claimed in  claim 1 , wherein the structure elements of opposite rows touch one another, in particular are joined to one another by welding or soldering.  
   
   
       32 . The flow passage as claimed in  claim 1 , wherein opposite rows of structure elements have the same depth T in the direction of flow P.  
   
   
       33 . The flow passage as claimed in  claim 1 , wherein opposite rows of structure elements have different depths T 1 , T 2  in the direction of flow P.  
   
   
       34 . The flow passage as claimed in  claim 1 , wherein the heat exchange surfaces which lie substantially opposite one another, and in particular the structure elements arranged thereon, are curved.  
   
   
       35 . The flow passage as claimed in  claim 1 , wherein the heat exchange surfaces which lie substantially opposite one another are heat-engineering primary surfaces or secondary surfaces, the secondary surfaces being formed in particular by fins, webs or the like which are preferably clamped, welded or soldered to the flow passage.  
   
   
       36 . The flow passage as claimed in  claim 1 , wherein the height h is in the range from 2 mm to 10 mm, in particular in the range from 3 mm to 4 mm, and is preferably around 3.7 mm.  
   
   
       37 . The flow passage as claimed in  claim 1 , wherein the flow passage is rectangular and has a width b which is in particular in the range from 5 mm to 120 mm, preferably in the range from 10 mm to 50 mm.  
   
   
       38 . The flow passage as claimed in  claim 1 , wherein a hydraulic diameter of the flow passage is in the range from  3  mm to  26  mm, in particular in the range from  3  mm to  10  mm.  
   
   
       39 . The flow passage as claimed in  claim 1 , wherein at least one, in particular each row of structure elements comprises in each case a plurality of structure elements.  
   
   
       40 . A heat exchanger, in particular an exhaust-gas cooler, in particular for a motor vehicle, having flow passages for a fluid, wherein at least one flow passage is designed as described in  claim 1 .  
   
   
       41 . The heat exchanger as claimed in  claim 39 , wherein the flow passages are formed as soldered or welded flat or rectangular tubes and the heat exchanger surfaces are formed as flat tube walls.  
   
   
       42 . The heat exchanger as claimed in  claim 1 , wherein the flow passages are formed by stacking plates or disks which have structure elements on top of one another.  
   
   
       43 . The heat exchanger as claimed in  claim 1 , wherein the structure elements are formed into the tube walls in particular by stamping.  
   
   
       44 . The heat exchanger as claimed in  claim 1 , wherein exhaust gas can flow through the tubes and a liquid coolant can flow around the tubes.  
   
   
       45 . The heat exchanger as claimed in  claim 1 , wherein the rows of structure elements are at a distance s from one another in the direction of flow which amounts to two to six times the length L of a structure element.  
   
   
       46 . The heat exchanger as claimed in  claim 1 , wherein between the rows with structure elements there are further rows with structure elements which project outward into fluid  2 .  
   
   
       47 . The heat exchanger as claimed in  claim 45 , wherein the outwardly projecting structure elements are supporting studs, webs or elements and touch one another or are welded or soldered to one another.  
   
   
       48 . The heat exchanger as claimed in  claim 45 , wherein the outwardly projecting structure elements contribute to improving the heat transfer.