Heat exchanger and a charge air cooling method

Abstract

The invention relates to a heat exchanger ( 1 ) for a charge air cooling, wherein water, in particular, condensation water in the form of droplets and/or fog is supplied and the heat exchanger ( 1 ) is provided with a hydrophobe surface in at least one partial area thereof.

1 . A heat exchanger for cooling charge air to which water, in particular condensation water, can be added in the form of droplets and/or mist, wherein the heat exchanger has a hydrophobic surface at least in a partial region.  
   
   
       2 . The heat exchanger as claimed in  claim 1 , wherein, in the region of the hydrophobic surface, the contact angle of a droplet is greater than 90°, preferably greater than 120° and in particular greater than 150°.  
   
   
       3 . The heat exchanger as claimed in  claim 1 , wherein separation edges are provided on the heat exchanger.  
   
   
       4 . The heat exchanger as claimed in  claim 3 , wherein the separation edges are formed by ends of web fins or gills of gill fins.  
   
   
       5 . The heat exchanger as claimed in  claim 1 , wherein the heat exchanger can be electrostatically charged at least in a partial region of the surface.  
   
   
       6 . The heat exchanger as claimed in  claim 5 , wherein the hydrophobic surface has dispersing, electrically conductive constituents.  
   
   
       7 . The heat exchanger as claimed in  claim 1 , wherein the heat exchanger has at least one region with a neutral or hydrophilic, electrically conductive surface.  
   
   
       8 . The heat exchanger as claimed in  claim 1 , wherein the fins of the heat exchanger have a spacing of a maximum of 2 mm, in particular a maximum of 1.5 mm.  
   
   
       9 . The heat exchanger as claimed in  claim 1 , wherein the fins have separation edges with a spacing of a maximum of 5 mm.  
   
   
       10 . The heat exchanger as claimed in  claim 1 , wherein the heat exchanger is designed in terms of flow such that, in the operating state which requires the admixture of condensation water, the flow speed in the region of the separation edges exceeds a value of 3 m/s, in particular 6 m/s.  
   
   
       11 . The heat exchanger as claimed in  claim 1 , wherein the heat exchanger comprises at least one or two mechanical vibration transducers.  
   
   
       12 . A method for cooling charge air, the charge air flowing through a heat exchanger and the charge air having water in the form of condensation water added to it, wherein the air flowing through the heat exchanger entrains condensation water which forms on the heat exchanger.  
   
   
       13 . The method as claimed in  claim 12 , wherein the condensation water which is entrained in the heat exchanger is conveyed onward in the charge air in the form of droplets or mist.  
   
   
       14 . The method as claimed in  claim 1 , wherein the condensation water accumulates in the heat exchanger in the form of droplets on hydrophobic faces, with the droplets which form having a contact angle of greater than 90°, preferably greater than 120° and in particular greater than 150°.  
   
   
       15 . The method as claimed in  claim 1 , wherein in at least one operating state in which condensation water is to be added to the charge air, the charge air in the heat exchanger flows, at least in the region of separation edges, at a flow speed of over 3 m/s, in particular over 6 m/s.  
   
   
       16 . The method as claimed in  claim 1 , wherein mechanical vibrations are generated in the heat exchanger, in particular by means of at least one vibration transducer which is coupled to the evaporator.  
   
   
       17 . The method as claimed in  claim 16 , wherein the mechanical vibrations are aligned substantially perpendicular to a heat transmitting face of the heat exchanger.