Heat exchanger and heating or air conditioning unit of a motor vehicle containing said heat exchanger

Abstract

The invention relates to a heat exchanger of a plate-type construction having first flow channels for a first heat exchange medium, each formed by a pair of plates, and having corrugated fins, around which a second heat exchange medium flows, arranged between neighboring plate pairs. In order to provide an improved heat exchanger which allows a more compact construction when used in a heating or air conditioning unit of a motor vehicle, it is proposed that the corrugated fins and at least one of the neighboring plate pairs form second flow channels for the second heat exchange medium and the second flow channels have a curved course, so that the second heat exchange medium undergoes a change of flow direction on flowing through the heat exchanger.

We claim:  
     
         1 . A plate-type heat exchanger comprising: 
 a plurality of stacked plates, with respective adjacent plates forming pairs of plates, the plates of the pairs being joined together to define a plurality of first flow channels therebetween for carrying a first heat exchange medium; and    fins arranged between neighboring pairs of said plates, said fins and at least one of said neighboring pairs of plates forming a plurality of second flow channels for carrying a second heat exchange medium;    wherein said fins are shaped such that the second heat exchange medium has a general flow direction in said second flow channels that is changed as it flows through the heat exchanger.    
     
     
         2 . A heat exchanger according to    claim 1   , wherein said fins comprise corrugated fins.  
     
     
         3 . A heat exchanger according to    claim 2   , wherein said second flow channels have a curved course for heat exchange medium flow.  
     
     
         4 . A heat exchanger according to    claim 3   , further comprising: 
 an inflow face for said second heat exchange medium; and    an exit face for said second heat exchange medium,    wherein said inflow face and said exit face are arranged at an angle to one another.    
     
     
         5 . A heat exchanger according to    claim 3   , wherein said second heat exchange medium comprises air.  
     
     
         6 . A heat exchanger according to    claim 5   , further comprising: 
 an inflow face for said second heat exchange medium; and    an exit face for said second heat exchange medium,    wherein said inflow face and said exit face are arranged at an angle to one another.    
     
     
         7 . A heat exchanger of    claim 3   , wherein at least two of said second flow channels have different lengths.  
     
     
         8 . A heat exchanger of    claim 7   , wherein said second flow channels include flow channels of shorter length and flow channels of longer length, and wherein the shorter second flow channels are located in an area of the heat exchanger in which the first heat exchange medium is at a warmer temperature than its temperature when in the area of the heat exchanger where the longer second flow channels are located.  
     
     
         9 . A heat exchanger of    claim 7   , further comprising: 
 at least one passage aperture for the first heat exchange medium,    wherein each of said second flow channels is of increasing length with increasing distance from said passage aperture.    
     
     
         10 . A heat exchanger of    claim 4   , wherein said second flow channels have an arcuate course for heat exchange medium flow.  
     
     
         11 . A heat exchanger of    claim 9   , wherein said second flow channels have an arcuate course for heat exchange medium flow.  
     
     
         12 . A heat exchanger of    claim 10   , wherein said second flow channels have a circular arcuate course for heat exchange medium flow.  
     
     
         13 . A heat exchanger of    claim 11   , wherein said second flow channels have a circular arcuate course for heat exchange medium flow.  
     
     
         14 . A heat exchanger of    claim 3   , wherein said first flow channels have a serpentine course for heat exchange medium flow.  
     
     
         15 . A heat exchanger of    claim 9   , wherein said first flow channels have a serpentine course for heat exchange medium flow.  
     
     
         16 . A heat exchanger of    claim 3   , wherein said fins are formed by punching sheet metal.  
     
     
         17 . A heat exchanger of    claim 9   , wherein said fins are formed by punching sheet metal.  
     
     
         18 . A heat exchanger of    claim 1   , wherein at least two of said second flow channels have different lengths.  
     
     
         19 . A heat exchanger of    claim 18   , wherein said plates are shaped as a radial sector of a circle and wherein said plurality of second flow channels have circular arcuate flow paths of different lengths.  
     
     
         20 . A heat exchanger of    claim 19   , further comprising: 
 at least one passage aperture for the first heat exchange medium located in said plates in an inner radial location,    wherein each of said second flow channels is of increasing length with increasing distance from said passage aperture.    
     
     
         21 . A heat exchanger system comprising: 
 a first plate-type heat exchanger, said first plate-type heat exchanger comprising: a plurality of stacked plates, with respective adjacent plates forming pairs of plates, the plates of the pairs being joined together to define a plurality of first flow channels therebetween for carrying a first heat exchange medium; and    fins arranged between neighboring pairs of said plates, said fins and at least one of said neighboring pairs of plates forming a plurality of second flow channels for carrying a second heat exchange medium;    wherein said fins are shaped such that the second heat exchange medium has a general flow direction in said second flow channels that is changed as it flows through the heat exchanger; and 
 a second plate-type heat exchanger,  
 wherein said first and second heat exchangers are integrally connected to one another.  
   
     
     
         22 . A heat exchanger system of    claim 21   , wherein said second heat exchanger comprises: 
 a plurality of stacked plates, with respective adjacent plates forming pairs of plates, the plates of the pairs being joined together to define a plurality of third flow channels therebetween for carrying a third heat exchange medium; and    fins arranged between neighboring pairs of said plates, said fins and at least one of said neighboring pairs of plates forming a plurality of fourth flow channels for carrying a fourth heat exchange medium;    wherein said fins are shaped such that the fourth heat exchange medium has a general flow direction in said fourth flow channels that is changed as it flows through the second heat exchanger.    
     
     
         23 . A heat exchanger system of    claim 22   , wherein in each of said first and second heat exchangers, said second and fourth heat exchange medium is in each case air and said second and fourth flow channels have a curved course for heat exchange medium flow, and 
 wherein each of said first and second heat exchangers further comprises at least one passage aperture for the first and third heat exchange medium, respectively, and each of said plurality of second and fourth flow channels are of increasing length with increasing distance from said respective passage aperture.    
     
     
         24 . A heat exchanger system of    claim 23   , wherein said first and second heat exchangers are connected to one another only in the vicinity of said their respective passage apertures.  
     
     
         25 . A heating or air conditioning unit comprising: 
 a first plate-type heat exchanger, said first plate-type heat exchanger comprising: a plurality of stacked plates, with respective adjacent plates forming pairs of plates, the plates of the pairs being joined together to define a plurality of first flow channels therebetween for carrying a first heat exchange medium; and    fins arranged between neighboring pairs of said plates, said fins and at least one of said neighboring pairs of plates forming a plurality of second flow channels for carrying a second heat exchange medium;    wherein said fins are shaped such that the second heat exchange medium has a general flow direction in said second flow channels that is changed as it flows through the heat exchanger.    
     
     
         26 . A heating or air conditioning unit of    claim 25   , further comprising a blower and wherein said first heat exchanger is positioned downstream of the blower.  
     
     
         27 . A heating or air conditioning unit of    claim 26   , wherein said blower comprises a radial blower.  
     
     
         28 . A heating or air conditioning unit of    claim 26   , further comprising: 
 a filter positioned downstream of said blower, and    wherein said first heat exchanger is positioned downstream of said filter.    
     
     
         29 . A heating or air conditioning unit of    claim 25   , wherein said first heat exchanger is an evaporator, and 
 the heating or air conditioning unit further comprising a second heat exchanger arranged downstream of said evaporator, 
 wherein said second heat exchanger comprises:  
 a plurality of stacked plates, with respective adjacent plates forming pairs of plates, the plates of the pairs being joined together to define a plurality of third flow channels therebetween for carrying a third heat exchange medium; and  
   fins arranged between neighboring pairs of said plates, said fins and at least one of said neighboring pairs of plates forming a plurality of fourth flow channels for carrying a fourth heat exchange medium;    wherein said fins are shaped such that the fourth heat exchange medium has a general flow direction in said fourth flow channels that is changed as it flows through the second heat exchanger.    
     
     
         30 . A heating or air conditioning unit of    claim 29   , wherein said second heat exchanger is a heater.  
     
     
         31 . A heating or air conditioning unit of    claim 30   , wherein each of said evaporator and said heater further comprises: 
 at least one passage aperture for the respective first and third heat exchange medium,    wherein each of said second and fourth flow channels is of increasing length with increasing distance from said respective passage aperture.    
     
     
         32 . A heating or air conditioning unit of    claim 30   , wherein said heater can adjust a flow of said third heat exchange medium.  
     
     
         33 . A heating or air conditioning unit of    claim 30   , further comprising a bypass positioned downstream of said evaporator for allowing air to bypass said heater.  
     
     
         34 . A heating or air conditioning unit comprising: 
 a first plate-type heat exchanger; and    a second plate-type heat exchanger,    wherein each of said first and second plate-type heat exchangers comprises: 
 a plurality of stacked plates, with respective adjacent plates forming pairs of plates, the plates of the pairs being joined together to define a plurality of first flow channels therebetween for carrying a first heat exchange medium; and  
   fins arranged between neighboring pairs of said plates, said fins and at least one of said neighboring pairs of plates forming a plurality of second flow channels for carrying a second heat exchange medium;    wherein said fins are shaped such that the second heat exchange medium has a general flow direction in said second flow channels that is changed in a circular arcuate path as it flows through each respective heat exchanger.    
     
     
         35 . A heating or air conditioning unit of    claim 34   , wherein each of said first and second heat exchangers further comprises: 
 at least one passage aperture for the first heat exchange medium, and    wherein each of said plurality of second flow channels is of increasing length with increasing distance from said passage aperture.    
     
     
         36 . A heating or air conditioning unit of    claim 35   , wherein said circular arcuate paths of said second flow channels of said first heat exchanger have a first center located in at least approximately the same vicinity as a second center of said circular arcuate paths of said second flow channels of said second heat exchanger, and 
 wherein said second heat exchanger is a heater.    
     
     
         37 . A heating or air conditioning unit of    claim 35   , wherein each of said first and second heat exchangers diverts air through approximately ninety (90) degrees.  
     
     
         38 . A heating or air conditioning unit of    claim 37   , further comprising an air mixing valve located on downstream of said first heat exchanger to direct at least a portion of air exiting said first heat exchanger to said second heat exchanger.  
     
     
         39 . A heating or air conditioning unit of    claim 34   , wherein said first heat exchanger further comprises an exit face, and said second heat exchanger comprises an inflow face, 
 wherein said exit face of said first heat exchanger is aligned approximately parallel to said inflow face of said second heat exchanger.    
     
     
         40 . A heating or air conditioning unit of    claim 34   , wherein said first and second heat exchangers are integrally connected to one another.  
     
     
         41 . A heat exchanger of    claim 4   , wherein said angle is approximately ninety (90) degrees.  
     
     
         42 . A heat exchanger of    claim 1   , further comprising in each pair of plates, a plurality of knobs on each said plate arranged opposite to one another and brazed together to connect said pair of plates.  
     
     
         43 . A method for assembling a heat exchange assembly comprised of a first plate-type heat exchanger; and a second plate-type heat exchanger, wherein each of said first and second plate-type heat exchangers comprises: a plurality of stacked plates, with respective adjacent plates forming pairs of plates, the plates of the pairs being joined together to define a plurality of first flow channels therebetween for carrying a first heat exchange medium; and fins arranged between neighboring pairs of said plates, said fins and at least one of said neighboring pairs of plates forming a plurality of second flow channels for carrying a second heat exchange medium, wherein said fins are shaped such that the second heat exchange medium has a general flow direction in said second flow channels that is changed as it flows through each respective heat exchanger, comprising: 
 assembling a stack of said plates for said first heat exchanger in alignment with one another and a stack of said plates for said second heat exchanger in alignment with each other, wherein at least some of the plates of said first heat exchanger are connected to corresponding plates of said second heat exchanger;    during said stack assembling, interposing said fins between each neighboring pair of plates for forming said second flow channels; and    brazing each of said pair of plates together on at least their outer circumference to form said first flow channels and brazing said fins to adjacent pairs of plates to form said second flow channels, whereby said first and second heat exchangers are produced in a single assembly operation.