Low-Temperature Coolant Cooler

Abstract

The invention relates to a low-temperature coolant cooler, for the indirect charge-air cooling on an internal combustion engine, with a number of flat tubes, through which 700 to 1,800 litres per hour of coolant flow during operation, which open out in coolant collectors ( 4,8 ) and air guide devices, in particular, air guide fins are arranged between the flat tubes around which charge air for cooling flows. In order to guarantee a constant cooling power over a large operating range of coolant throughput, said low-temperature coolant cooler comprises the following features: a) the flat tubes have a depth ( 23 ) of less than or equal to 20 millimetres, b) the coolant flowing through the flat tubes is deflected a maximum of two times in the collectors ( 4, 8 ) and c) the flat tubes are provided with internal turbulence generating devices.

1 . A low-temperature coolant cooler for the indirect charge air cooling of an internal combustion engine, comprising a plurality of flat tubes which, in operation, are traversed by 700 to 1800 liters of coolant per hour and are connected to coolant collecting tanks, and air guide devices arranged between the flat tubes, around whereby charge air which is to be cooled flows the air guide devices for cooling wherein:
 a) the flat tubes have a depth which is less than/equal to 20 millimeters;   b) the coolant which traverses the flat tubes changes flow direction a maximum of two times in the collecting tanks; and   c) the flat tubes are equipped at the inside with turbulence-generating devices.   
   
   
       2 . The low-temperature coolant cooler as claimed in  claim 1 , wherein the flat tubes with the turbulence-generating devices are designed in such a way that the ratio between the maximum and minimum pressure loss in the flat tubes is less than 3 for coolant throughputs of 700 to 1800 liters per hour. 
   
   
       3 . The low-temperature coolant cooler as claimed in  claim 2 , wherein the ratio between the maximum and minimum Nusselt number in the flat tubes is less than 3 for coolant throughputs of 700 to 1800 liters per hour or of 0.2 to 0.5 kg/s. 
   
   
       4 . The low-temperature coolant cooler as claimed in  claim 1 , wherein the flat tubes have inwardly aligned indentations on at least one of their flat sides. 
   
   
       5 . The low-temperature coolant cooler as claimed in  claim 1 , wherein turbulence inserts are arranged in the flat tubes. 
   
   
       6 . The low-temperature coolant cooler as claimed in  claim 2 , wherein the flat tubes have inwardly aligned indentations on at least one of their flat sides. 
   
   
       7 . The low-temperature coolant cooler as claimed in  claim 3 , wherein the flat tubes have inwardly aligned indentations on at least one of their flat sides. 
   
   
       8 . The low-temperature coolant cooler as claimed in  claim 2 , wherein turbulence inserts are arranged in the flat tubes. 
   
   
       9 . The low-temperature coolant cooler as claimed in  claim 3 , wherein turbulence inserts are arranged in the flat tubes. 
   
   
       10 . The low-temperature coolant cooler as claimed in  claim 4 , wherein turbulence inserts are arranged in the flat tubes.