Heat exchanger

Abstract

A heat exchanger for a motor vehicle is provided having at least one block formed by tubes arranged parallel to one another and by fins arranged between the tubes. The tubes form multiple first flow ducts through which a first fluid can flow. The regions between the tubes form multiple second flow ducts through which a second fluid can flow around the tubes. The heat exchanger also has a first collecting box with a first fluid port and a second collecting box with a second fluid port. The first flow ducts are in fluid communication with a first cooling circuit via the first fluid port, the second fluid port, and the collecting boxes. The first collecting box or the second collecting box also has a third fluid port that, together with its respective collecting box and further fluid port, are in fluid communication with a second cooling circuit.

1 . Heat exchanger, in particular a coolant cooler, for a motor vehicle, having at least one block which is formed by tubes arranged parallel to one another and by fins arranged between the tubes, wherein the tubes form multiple first flow ducts through which a first fluid can flow, wherein the regions between the tubes form multiple second flow ducts through which a second fluid can flow around the tubes, having a first collecting box on which a first fluid port is arranged, having a second collecting box on which a second fluid port is arranged, wherein the first flow ducts are in fluid communication with a first cooling circuit via the first fluid port, the second fluid port and the collecting boxes, wherein the first collecting box or the second collecting box has a third fluid port, wherein the third fluid port, the respective collecting box and the second fluid port of the respective collecting box are in fluid communication with a second cooling circuit. 
     
     
         2 . Heat exchanger according to  claim 1 , wherein the first fluid port, the second fluid port and the third fluid port are arranged in a direction perpendicular to the plane of the flow ducts or flat tubes. 
     
     
         3 . Heat exchanger according to  claim 1 , wherein, in the collecting box which has two fluid ports, the heat exchanger has a means for reducing and/or preventing a fluid flow between the two fluid ports. 
     
     
         4 . Heat exchanger according to  claim 3 , wherein the means for reducing and/or preventing a fluid flow between the two fluid ports of the respective collecting box is a flap or a valve or a partition. 
     
     
         5 . Heat exchanger according to  claim 3 , wherein, by way of the means for reducing and/or preventing a fluid flow between the two fluid ports of the respective collecting box, the pressure loss in the respective collecting box between the two fluid ports of the collecting box can be varied as a function of a pressure difference between the third fluid port and the respective fluid port of the other collecting box or as a function of the fluid temperature in the second cooling circuit. 
     
     
         6 . Heat exchanger according to  claim 1 , wherein the second cooling circuit is formed between the second fluid port and the third fluid port. 
     
     
         7 . Heat exchanger according to  claim 1 , wherein the heat exchanger is of multi-part construction, wherein each subsection of the heat exchanger is in fluid communication with a first collecting box and also with a second collecting box, wherein each subsection of the heat exchanger has two fluid ports. 
     
     
         8 . Arrangement of a heat exchanger according to  claim 1  in a motor vehicle, wherein a component to be cooled is integrated into the second cooling circuit, or a component to be cooled and a fluid pump are integrated into the second cooling circuit. 
     
     
         9 . Arrangement of a heat exchanger according to  claim 8 , wherein the first cooling circuit is in fluid communication with the second cooling circuit via a connecting point outside the heat exchanger.