Patent Publication Number: US-7717165-B2

Title: Heat exchanger, especially charge-air/coolant radiator

Description:
The invention relates to a heat exchanger, especially charge-air/coolant radiator, of disk-type construction, according to the precharacterizing clause of claim  1 . 
     In the case of conventional charge-air/coolant radiators of disk-type construction, the charge air and the coolant are introduced into the disks via a single connecting branch in each case which has a circular cross section. A charge-air/coolant radiator of this type can still leave something to be desired in particular with regard to the cooling capacity. 
     It is the object of the invention to provide an improved heat exchanger. 
     This object is achieved by a heat exchanger with the features of claim  1 . Advantageous refinements are the subject matter of the subclaims. 
     According to the invention, a heat exchanger, especially charge-air/coolant radiator, of disk-type construction is provided, with two adjacent disks defining an intermediate space through which a heat exchanger medium, in particular a coolant, preferably a mixture with water and glycol, or a second medium to be cooled or to be heated flows, the entry and/or exit region of the heat exchanger medium and/or second medium being expanded at least on the discharge side or inflow side. In this connection, in particular the entry and/or exit region of a fluid to be cooled, for example charge air, which forms the second medium, is of expanded design. 
     Instead of a charge-air/coolant radiator, use can also be made of any other desired, correspondingly constructed heat exchanger, for example an oil cooler. A heat exchanger of this type which is designed in accordance with the invention permits good distribution of the corresponding medium over the surface, which is relevant for the heat exchange, of the individual disks which form the heat exchanger. The uniform distribution of the flow reduces the boiling problems in heat exchangers used in critical regions of this type. 
     The region preferably runs rectilinearly at least over a third, in particular over half, of the width of the disk. 
     The region preferably runs at least over part of the width of the disk perpendicularly or essentially transversely, i.e. at an angle of 80° to 100°, to the average flow direction of the second medium, in particular a fluid which is to be cooled. 
     The opening for the second medium in an end region of the disk preferably extends essentially over the entire surface of the same, except for edge regions and regions in which passages for the heat exchanger medium are arranged. 
     At least two heat exchanger medium passages are preferably provided per heat exchanger medium inlet and/or outlet. A heat exchanger designed in such a manner permits good distribution of the heat exchanger medium over the surface, which is relevant for the heat exchange, of the individual disks which form the heat exchanger. The uniform distribution of the flow reduces the boiling problems in the case of heat exchangers used in critical regions of this type. In this case, the heat exchanger medium passages, in the same manner as the entry and/or exit regions of the medium to be cooled/heated, are preferably formed by apertures, in particular aligned with one another, in the individual disks. 
     The distribution of the heat exchanger medium is assisted by an axially symmetrical configuration of the disks with respect to their longitudinal axis with regard to the heat exchanger medium passages. If, furthermore, the disks are of axially symmetrical design with respect to their transverse axis with regard to the heat exchanger medium passages, then the installation is simplified. 
     A single heat exchanger medium inlet and/or a single heat exchanger medium outlet, having a branching and/or junction, is preferably provided. This permits a relatively simple construction with improved heat transfer owing to the better distribution of the flow. 
     The branching and/or the junction are preferably designed in the shape of an arc of a circle, with the result that a space-saving construction around the bolts or the like holding the individual disks together is possible. 
     A bend of 30° to 90° is preferably provided—as seen in the direction of flow—in the region of the branching and/or of the junction, with the forked part of the branching and/or junction being oriented parallel to the disks. 
     The heat exchanger medium inlet, which merges into two heat exchanger medium passages after the branching, preferably runs parallel to the heat exchanger medium passages while the two-part part of the branching is preferably arranged in a plane lying perpendicularly thereto. The heat exchanger medium outlet, which merges from two heat exchanger medium passages into the junction, preferably runs parallel to the heat exchanger medium passages while the two-part part of the branching is preferably arranged in a plane lying perpendicularly thereto. This permits a compact and space-saving construction of the heat exchanger. As an alternative, supply may also take place by means of two individual, separately formed pipes which are connected to each other via a Y-shaped connecting piece. 
     A heat exchanger of this type is preferably used as a charge-air/coolant radiator for cooling the charge air. In this connection, a mixture with water and glycol is preferably used as the heat exchanger medium (coolant). 
    
    
     
       The invention is explained in detail below using three exemplary embodiments with reference to the drawing. In the drawing: 
         FIG. 1  shows a schematized, perspective exploded illustration of a charge-air/coolant radiator of disk-type construction according to the first exemplary embodiment, 
         FIG. 2  shows a perspective illustration of the charge-air/coolant radiator of  FIG. 1 , 
         FIG. 3  shows a section through the charge-air/coolant radiator of  FIG. 1  along line III-III in  FIG. 4 , 
         FIG. 4  shows a section through the charge-air/coolant radiator of  FIG. 1  along line IV-IV in  FIG. 3 , 
         FIG. 5  shows an enlarged detail of a coolant disk, 
         FIG. 6  shows an enlarged detail of a coolant disk according to a second exemplary embodiment, and 
         FIG. 7  shows an enlarged detail of a coolant disk according to a third exemplary embodiment. 
     
    
    
     A charge-air/coolant radiator  1  used as a heat exchanger between charge air and coolant has a plurality of coolant disks  2  stacked on one another. In this case, two inlet openings  3  and two outlet openings  4  are provided in each coolant disk  2 , through which openings coolant, as the heat exchanger medium, is supplied to or removed from the intermediate spaces of the coolant disks  2 . The direction of flow is indicated in the figures by arrows. The coolant spreads here after being inlet through the inlet openings  3  over the entire width of the intermediate spaces of the coolant disks  2  and flows uniformly in the direction of the outlet openings  4  (see  FIG. 3 ), so that the entire length and width of the intermediate spaces between the inlet and outlet openings  3  and  4  have the flow passing uniformly through them, and an optimum transfer of heat from the charge air which is to be cooled and which flows between the individual coolant disks  2  through the charge-air/coolant radiator  1  can take place. 
     The openings  3  and  4  of the coolant disks  2  which are stacked on one another form coolant passages  5  and  6 . For this, the regions of the openings  3  and  4  are of correspondingly raised design, so that there is sufficient intermediate space for the charge air to be able to flow between the coolant disks  2  and be cooled. 
     The two coolant passages  5  begin—as seen in the direction of flow of the coolant—at a branching  7  which has a forking  8  in the shape of an arc of a circle and has a coolant inlet  9  which is arranged centrally in the arc of the circle of the same and is arranged parallel to the coolant passages  5 . The coolant supplied through the coolant inlet  9  is thus divided uniformly between the two coolant passages  5 . 
     The outlet is of corresponding design to the inlet. The two coolant passages  6  thus end with a junction  10  which is of corresponding design to the branching  7  and has a coolant outlet  11 . 
     The charge air (second medium) is supplied via a charge-air inlet  20 , and then is supplied via a charge-air passage  21 , which is formed by openings  22  in the coolant disks  2  stacked on one another, to the intermediate spaces between the intermediate spaces, through which the coolant flows, of the coolant disks  2  and passes via openings  23 , which are formed on the other side of the coolant disks  2  and form a second charge-air passage  24 , to the charge-air outlet  25 . 
     Unlike in the prior art (illustrated by dashed lines in  FIG. 5 ), the openings  22  and  23  are not circular but rather have a region  26  which, according to the first exemplary embodiment, runs essentially rectilinearly, with it being arranged perpendicularly to the normal direction of flow of the charge air, so that, in this region  26 , it is arranged tangentially with respect to the conventional shape which corresponds to the inner circle of the openings  22  and  23 . 
     The openings  22  and  23  each take up the entire end region of the coolant disk  2 , apart from an outer edge  27 , the two coolant passages  5  and  6  and an edge  28  in each case surrounding the coolant passages. 
     According to a second exemplary embodiment which is illustrated in  FIG. 6 , the region  26  of the opening  23  is designed in such a manner that it extends over the entire end region of the coolant disks  2 , with it being arranged perpendicularly to the average direction of flow of the charge air. In this case, the coolant passages are offset further inward, thus producing the shape of a rounded triangle. The other side of the coolant disk  2  is of corresponding design. 
     According to a third exemplary embodiment illustrated in  FIG. 7 , the opening  23  corresponds approximately to the opening  23  of the second exemplary embodiment, with just one coolant passage being provided which is displaced laterally into the region of the opening  23 , so that the opening  23  takes up the end region of the coolant disk  2 , apart from an outer edge  27 , the coolant passage and an edge  28  surrounding the coolant passage. The other side of the coolant disk  2  is of corresponding design, in particular is axially symmetrical to the central transverse axis or is point-symmetrical with respect to the central point of the coolant disk. 
     LIST OF REFERENCE NUMBERS 
     
         
           1  Charge-air/coolant radiator 
           2  Coolant disk 
           3  Inlet opening 
           4  Outlet opening 
           5  Coolant passage 
           6  Coolant passage 
           7  Branching 
           8  Fork 
           9  Coolant inlet 
           10  Junction 
           11  Coolant outlet 
           20  Charge-air inlet 
           21  Charge-air passage 
           22  Opening 
           23  Opening 
           24  Second charge-air passage 
           25  Charge-air outlet 
           26  Region 
           27  Outer edge 
           28  Edge