Heat Exchanger, in Particular for an Over Critical Cooling Circuit

Abstract

The invention relates to a heat exchanger ( 1 ), in particular for an over critical cooling circuit. Said heat exchanger comprises a block consisting of tubes (R) and ribs. A gaseous medium, in particular air, can flow over said ribs. A second medium, in particular a coolant, can flow through the tubes (R), which are arranged in at least four rows ( 1.1, 1.2, 1.3, 1.4 , in particular in a cross-counter flow in relation to the gaseous medium.

1 . A heat exchanger, in particular for a supercritical refrigeration cycle, having a block comprising tubes and fins, it being possible for a gaseous medium, in particular air, to flow over the fins, and it being possible for a second medium, in particular a refrigerant, to flow through the tubes, which are arranged in a plurality of rows, in particular in cross-countercurrent to the gaseous medium, wherein at least four rows of tubes are arranged in series in the direction of flow L of the gaseous medium.  
   
   
       2 . The heat exchanger as claimed in  claim 1 , wherein at least five rows of tubes are arranged in series.  
   
   
       3 . The heat exchanger as claimed in  claim 1 , wherein six rows of tubes are arranged in series.  
   
   
       4 . The heat exchanger as claimed in  claim 1 , wherein the tubes are formed as flat tubes and the fins are formed as corrugated fins.  
   
   
       5 . The heat exchanger as claimed in  claim 4 , wherein the flat tubes are formed as extruded multichamber tubes.  
   
   
       6 . The heat exchanger as claimed in one of  claim 1 , wherein medium can flow through the tubes R of a row of tubes in parallel.  
   
   
       7 . The heat exchanger as claimed in  claim 6 , medium can flow through the rows of tubes in series.  
   
   
       8 . The heat exchanger as claimed in  claim 1 , wherein at least one row of tubes is divided into tube segments with individual tubes through which medium can flow in succession.  
   
   
       9 . The heat exchanger as claimed in  claim 8 , wherein the rows of tubes which are divided into tube segments are arranged upstream of the undivided rows of tubes as seen in the direction of flow L of the gaseous medium.  
   
   
       10 . The heat exchanger as claimed in  claim 8 , wherein all the rows of tubes are divided into tube segments through which medium can flow in series.  
   
   
       11 . The heat exchanger as claimed in  claim 10 , wherein the tube segments have different numbers of tubes.  
   
   
       12 . The heat exchanger as claimed in  claim 10 , wherein the tube segments have approximately equal numbers of tubes.  
   
   
       13 . The heat exchanger as claimed in  claim 10 , wherein the ratio a/b of the numbers a, b of the tubes of two tube segments in a row of tubes is in a range from 0.7 to 1.35.  
   
   
       14 . The heat exchanger as claimed in  claim 8 , wherein the tube segments are connected by header tubes and are separated by partition walls in the header tubes.  
   
   
       15 . The heat exchanger as claimed in  claim 1 , wherein adjacent rows of tubes are connected to one another by diverter members (V).  
   
   
       16 . The heat exchanger as claimed in  claim 4 , wherein the corrugated fins of the individual rows of tubes are thermally decoupled.  
   
   
       17 . The heat exchanger as claimed in  claim 4 , wherein each case two rows of tubes have common, continuous corrugated fins.  
   
   
       18 . The heat exchanger as claimed in  claim 4 . wherein all the rows of tubes have common, continuous corrugated fins.  
   
   
       19 . The heat exchanger as claimed in  claim 4 , wherein the flat tubes of different rows of tubes are arranged aligned with one another.  
   
   
       20 . The heat exchanger as claimed in  claim 4 , wherein the flat tubes of different rows of tubes are arranged offset with respect to one another.  
   
   
       21 . The heat exchanger as claimed in  claim 4 , wherein the transverse pitch t R  of the flat tubes is identical in all the rows of tubes.  
   
   
       22 . The heat exchanger as claimed in  claim 4 , wherein the transverse pitch t R  of adjacent rows of tubes varies.  
   
   
       23 . The heat exchanger as claimed in  claim 1 , wherein the block has a finned end face with a height H and a width B, and in that the ratio of B/H is in the range from 0.8 to 1.2.  
   
   
       24 . The heat exchanger as claimed in  claim 23 , wherein the end face is approximately square in form.  
   
   
       25 . The heat exchanger as claimed in  claim 23 , wherein the end face has a surface area A in a range from 4 dm 2  to 16 dm 2 .  
   
   
       26 . The use of the heat exchanger as claimed in  claim 1  as a gas cooler in a supercritical refrigeration cycle of a motor vehicle air-conditioning system, which is preferably operated with R744 (CO 2 ).