Abstract:
A plate-type heat exchanger, in particular for motor vehicles, is provided that includes a plurality of plate groups in order to form first and second and/or third flow paths, a spatial region for fourth flow paths being formed between adjacent plate groups, the plate groups having at least one plate pair having a first and second plate in order to form the first flow paths and the second flow paths, wherein a third plate can be arranged in interaction with one of the first or one of the second plates in order to form the third flow path.

Description:
[0001]    This nonprovisional application is a continuation of International Application No. PCT/EP2012/076855, which was filed on Dec. 21, 2012, and which claims priority to German Patent Application No. 10 2011 090 159.0, which was filed in Germany on Dec. 30, 2011, and which are both herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a plate-type heat exchanger, particularly for motor vehicles, with a plurality of plate groups to form first and second and/or third flow paths, whereby a spatial region for the fourth flow paths is formed between adjacent plate groups. 
         [0004]    2. Description of the Background Art 
         [0005]    Heat exchangers are provided in motor vehicles in a wide variety and for a multitude of different purposes. Thus, evaporators are used in climate control systems in order to cool the air by evaporation of the refrigerant in flow paths flowing through the evaporator, in order to bring about an air conditioning and dehumidification in the vehicle interior. Flat tube-type or plate-type evaporators have become known for this purpose. 
         [0006]    In regard to motor vehicles, the main trend in recent times has been to reduce the fuel consumption of a motor vehicle and the CO 2  emissions associated therewith. This is also achieved in the case of motor vehicles with an internal combustion engine in that during temporary idling caused by stopping of the vehicle at a traffic light or in similar situations, for example, the vehicle&#39;s combustion engine is turned off. As soon as the vehicle is reactivated to drive by actuation of the gas pedal or the clutch pedal, the internal combustion engine is automatically restarted. This technology is also called the start-stop method. Such start-stop methods have already been implemented in low-consumption motor vehicles. For commercially available vehicle climate control systems with a cooling circuit according to the vapor compression cycle, the compressor of the cooling circuit is usually powered by a belt drive, driven by the vehicle&#39;s driving engine. When the engine is idle, i.e., when the compressor drive is not working, the climate control system can no longer be described as cold-producing. With a turned-off engine in the start-stop operation, the air conditioning of the motor vehicle can therefore no longer operate and provide a cooling capacity for cooling the vehicle&#39;s interior. As a consequence of this situation, the evaporator of the climate control system warms up relatively quickly and the air flowing through the evaporator is cooled only slightly or too little. For one thing this causes the interior vehicle temperature to rise and to affect the physical comfort of the vehicle passengers negatively. 
         [0007]    Apart from the temperature reduction, a dehumidifying process also occurs in a vehicle climate control system, because the moisture in the air condenses in the evaporator and leaves the vehicle through a condensate outlet. The air flowing through the evaporator is therefore dehumidified and enters dehumidified the motor vehicle interior. In the case of the active start-stop operation, the dehumidification of the air entering the vehicle interior can thus no longer be sufficiently assured, so that the humidity in the vehicle interior increases during the active start-stop operation. This also results in an increase in humidity which is perceived as unpleasant and uncomfortable by the vehicle passengers. 
         [0008]    In order to prevent or slow down these temperature- and humidity-increasing processes, the so-called storage evaporator was developed which, in addition to the actual evaporator function, also comprises a cold storage medium that removes heat from the air flowing through the evaporator in an active start-stop operation and continues to cool and dehumidify it. 
         [0009]    These storage evaporators have been disclosed, for example, in DE 102006028017, which corresponds to U.S. Pat. No. 8,495,894, and which is incorporated herein by reference. The storage evaporator disclosed has two separate heat exchanger blocks, the evaporator and the storage section, which are produced in different production processes and are connected together just before the soldering process and are then soldered together to a unit. The main evaporator has two flat tube rows, arranged one behind the other in the air flow direction, and the storage section is connected downstream of these two flat tube rows in the air flow direction. The storage part has double-tube rows with two tubes being inserted into one another, whereby the refrigerant flows in the interior of the inner tube and the cold storage medium is disposed in the space between the outer tube and the inner tube. 
         [0010]    However, in the conventional art, the corresponding production process is very complex and expensive, because many different parts have to be matched, joined, and calibrated in order to be able to produce a properly functioning heat exchanger. In particular, a double tube with covered tube entries proves to be relatively complex, the number of parts is very high with at the same time a high number of different parts and compliance with tolerances represents a risk for process capability due to the many structural parts. This in turn means an increased risk of leakage, so that apart from the parts costs the risk of the reject rates also increases. 
       SUMMARY OF THE INVENTION 
       [0011]    It is therefore an object of the invention to provide a heat exchanger, which is simple to manufacture and results in lower costs than the heat exchangers known in the conventional art at a simultaneously reduced complexity and reduced rejection rate. 
         [0012]    In an exemplary embodiment, a plate-type heat exchanger is provided, particularly for motor vehicles, with a plurality of plate groups to form first and second and/or third flow paths, whereby a spatial region for the fourth flow paths is formed between adjacent plate groups, the plate groups has at least one plate pair having a first and second plate to form the first flow paths and the second flow paths, whereby a third plate can be arranged in conjunction with one of the first or one of the second plates in order to form the third flow path. The plate-type design avoids the need for the insertion of flat tubes into one another, which simplifies the production process. The heat exchanger of the invention can provide a heat exchanger for a plurality of fluids participating in the heat transfer. Thus, a heat exchanger can be provided which can be operated as a storage evaporator, whereby in this heat exchanger refrigerant flows in the first and second flow path, a cold storage medium is provided in the third flow path, and the air to be cooled flows through the fourth flow path. As an alternative exemplary embodiment, however, a heater with a heat-storage unit can also be provided, where a heat-transporting fluid, such as, for example, a coolant of the internal combustion engine, flows in the first and second flow path, a heat storage medium is provided in the third flow path, and the air to be heated flows through the fourth flow path. 
         [0013]    According to an embodiment of the invention, the plates of the heat exchanger can have at least in part openings and/or cups as connecting and interconnecting regions and have channel-forming structures, such as embossings, to form flow paths between connecting regions. These can preferably be produced by embossing or deep-drawing, so that both the cups are drawn from the flat plate or the flat strip and the channel-forming structures are embossed or drawn. With this process or tool the openings can also be stamped out. 
         [0014]    The first plate of the plate group at two opposite end regions can have two connecting regions each as an inlet and/or outlet of the first and second flow path and a channel-forming structure is provided between each of the two connecting regions to form the first and second flow path, whereby, furthermore, two openings and/or cups are provided at opposite ends of the first plate for connection to the third flow path. A rectangular plate, for instance, is provided with two short and two long sides, whereby then advantageously the particular connecting regions of the first plate are arranged on the two opposite short sides. In this regard, the flow paths of the first and second structures formed as flow paths would then be directed, for instance, in the direction of the long sides. As a result, a relatively long first and second flow path for the flowing fluid, such as for the refrigerant, can be created and a shorter fourth flow path for the air. This reduces the pressure drop for air and the noise of the air in the evaporator. 
         [0015]    The second plate of the plate group at two opposite end regions can have two connecting regions each as an inlet and/or outlet of the first and second flow path and a channel-forming structure between two connecting regions to form the first or second flow path, whereby, furthermore, two openings and/or cups are provided at opposite ends of the first plate for connection to the third flow path. 
         [0016]    Also, no channel-forming structure or a volume-modified or reduced channel-forming structure can be formed between the two connecting regions of the second or first flow path. This is advantageous, so that the third flow path can be disposed in this region, without there being highly interfering effects of the first or second flow path. 
         [0017]    A third plate can be connected to the second plate such that it is arranged in the plate region without a channel-forming structure or with a modified or reduced channel-forming structure and forms the third flow path and has openings and/or cups, which communicate with the openings and cups of the third flow path of the second plate as an inlet or outlet. This is advantageous because the third flow path can then be disposed in this region, without there being interfering effects of the first or second flow path. 
         [0018]    The connecting and interconnecting regions of the three flow paths can be arranged such that a connecting and interconnecting region of each flow path is arranged substantially next to one another at an opposite end of the plate or plate group. 
         [0019]    A connecting and interconnecting region of the third flow path can be arranged between the connecting and interconnecting regions of the first and second flow path. This permits a uniform arrangement of connections, because the connection of the third flow channel can thus be kept smaller than the connection of the two other flow channels. 
         [0020]    A connecting and interconnecting region of the third flow path can be arranged next to connecting and interconnecting regions of the first and second flow path. 
         [0021]    The cup-shaped connecting and interconnecting regions and/or the channel-forming structures of the first and/or second and/or third plate can be made equally deep relative to the first and/or second and/or third flow channel in the direction perpendicular to the plane of the plate. This permits the flow channels in their depth to be adapted to requirements, so that, for example, the first and second flow channels can be designed with a similar flow cross section. 
         [0022]    The cup-shaped connecting and interconnecting regions and/or the channel-forming structures of the first and/or second and/or third plate in regard to the first and/or second and/or third flow channel can be formed in a direction perpendicular to the plane of the plate such that the depth of the channel-forming structures of the first plate is greater or smaller than the depth of the channel-forming structures of the second and/or third plate in regard to the second and third flow path. This permits the flow channels in their depth to be adapted to requirements, so that, for example, the first and second flow channels can be designed with a greater flow cross section than the third flow channels. 
         [0023]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein: 
           [0025]      FIG. 1  illustrates a first exemplary embodiment of a heat exchanger of the invention; 
           [0026]      FIG. 2  illustrates a view of a detail enlargement according to  FIG. 1 ; 
           [0027]      FIG. 3  illustrates a view of a plate arrangement of a heat exchanger; 
           [0028]      FIG. 4  illustrates a view of a plate arrangement of a heat exchanger; 
           [0029]      FIG. 5  illustrates a view of a plate arrangement of a heat exchanger; 
           [0030]      FIG. 6  illustrates a view of a plate arrangement of a heat exchanger; 
           [0031]      FIG. 7  illustrates a view of a plate arrangement of a heat exchanger; 
           [0032]      FIG. 8  illustrates a view of a plate arrangement of a heat exchanger; 
           [0033]      FIG. 9  illustrates a view of a plate arrangement of a heat exchanger; 
           [0034]      FIG. 10  illustrates a view of a plate arrangement of a heat exchanger; 
           [0035]      FIG. 11  illustrates a view of a plate arrangement of a heat exchanger in a sectional illustration; 
           [0036]      FIG. 12  illustrates a view of a plate arrangement of a heat exchanger in a sectional illustration; 
           [0037]      FIG. 13  illustrates a view of a plate arrangement of a heat exchanger in a sectional illustration; 
           [0038]      FIG. 14  a view of a plate arrangement of a heat exchanger in a sectional illustration; 
           [0039]      FIG. 15  illustrates a view of a plate arrangement of a heat exchanger in a sectional illustration; and 
           [0040]      FIG. 16  illustrates a view of a plate arrangement of a heat exchanger in a sectional illustration. 
       
    
    
     DETAILED DESCRIPTION 
       [0041]      FIG. 1  shows a heat exchanger  1  with a first top header  2  and a second bottom header  3 , which are arranged at two opposite ends of the heat exchanger and extend in a transverse direction, and having a block  4 , in which the block network includes plates that are joined together to form plate groups, a plurality of plate groups  5  being arranged next to one another in order to form the heat exchanger network. Spatial regions  6 , which are used for the flow of air through the heat exchanger, for example, are provided between two adjacent plate groups  5 . The air flow direction is indicated by arrow  26 . Fins such as, for example, corrugated fins can also be provided in the indicated spatial regions to improve the heat transfer. 
         [0042]    It is evident that the top and bottom headers have substantially three flow channels, which are indicated by the three connecting pieces  7 ,  8 ,  9 . These flow channels of the header extend in the transverse direction at the top side and at the bottom side of the heat exchanger. Flow channels, which divide into first, second, and third flow channels  10 ,  11 ,  12 , are provided between the headers. Flow channels  12  are formed between opposite connecting regions  8 , flow channels  11  are formed between opposite connecting regions  9 , and flow channels  10  are formed between opposite connecting regions  7 . 
         [0043]    As is evident in  FIG. 3 , a plate group has a first plate  13 , a second plate  14 , and a third plate  15 . First plate  13 , also evident in  FIG. 4 , has three connecting and interconnecting regions  7 ,  8 ,  9  at its top narrow side, whereby these connecting and interconnecting regions are also arranged at the bottom opposite narrow side of plate  13 . In this case, connecting and interconnecting regions  7  and  9  are formed as cups projecting out of the plane of the plate in a direction oriented perpendicular thereto. Connecting and interconnecting regions  8  can advantageously also be formed as cups, but also as openings without cups, as is evident in  FIG. 3  or in  FIG. 4 . 
         [0044]    Channel-forming structures  16 ,  17 , which connect the cup-shaped connecting and interconnecting regions to a flow channel, are provided between connecting and interconnecting regions  7  or  9  at the top and bottom end region of a plate. Here, channel-forming structure  16  forms a first flow channel and channel-forming structure  17  a second flow channel. As is evident, second plate  14  also has two cups  18 ,  19  at the top and bottom end region of the short sides, whereby furthermore an opening  25  is provided for the flow of a third medium through a third flow channel. Connecting and interconnecting regions  18  of second plate  14  are in turn connected together by means of a channel-forming structure  20 . Channel-forming structure  20  works together with channel-forming structure  16  in the case of connected first and second plates  13 ,  14 , in order to form a first flow channel. With the two plates  13  and  14  connected to one another, a first flow channel arises formed by channel-forming structures  16  and  20 , and a second flow channel is formed by channel-forming structure  17 . It follows that in connecting the two plates  13 ,  14 , the first flow channel has a greater depth perpendicular to the plate plane than the second flow channel. The first flow channel is therefore formed by the channel-forming structures, such as embossings  16  and  20 , with the second flow channel being formed solely by channel-forming structure  17 , because no channel-forming structure is provided in the second plate between cups  19 . The channel-forming structures are preferably embossings in the plate, resulting in indentations and thereby channels. 
         [0045]    It can also be seen that a further plate  15  is placed on second plate  14  and is connected sealingly to it. Plate  15  with plate  14  in its flat region thereby forms flow channel  17 , because flow channel  17  is formed between the top connection and bottom connection  22  with plate  15  being arranged on the planar region  21  provided on second plate  14 . Connecting region  22  of plate  15 , formed as a cup or passage, for example, is arranged such that it aligns with opening  25  and opening  8  of the first or second plate in the horizontal direction, for instance. 
         [0046]    As can be seen, first plate  13  and second plate  14  have a projecting circumferential edge, by means of which the two plates can be soldered sealingly to one another. Plate  15  also has a circumferential edge  23 , by means of which plate  15  can be soldered onto planar region  21  of plate  14 . 
         [0047]      FIG. 3  shows how first plate  13 , second plate  14 , and third plate  15  can be arranged relative to one another and also can be connected to one another. 
         [0048]      FIG. 4  shows a plate group having a first, second, and third plate  13 ,  14 ,  15  connected to one another, whereby the left half of the figure shows the plate group from the side of second and third plate  14 ,  15 , whereas in the right half of the figure the plate group can be viewed from first plate  13  outward. 
         [0049]      FIG. 5  shows the sequential arrangement of three plate groups having first, second, and third plates  13 ,  14 ,  15 , with the front view corresponding to first plate  13 , and plate  14  being arranged connected thereto, and of plate  15  only cup  22  can be seen as a passage. 
         [0050]      FIG. 5  shows the arrangement of the connection of the cups of plates  13  and  14 , which soldered one onto the other project from plate pair  13 ,  14 , whereby adjacent plate pairs  13 ,  14  are soldered fluid-tight adjoining one another with these cups. Connecting cups  22  are arranged between cups  7  and  9 , whereby these are formed deeper in the axial direction than cups  7 ,  9  of the first plate and cups  18 ,  19  of the second plate, while the first plate has no cup in the area of passage  8 . Therefore, cup  22  of the third plate must substantially have the sum of the depths of cups  7  and  18  or  9  and  19 . 
         [0051]      FIG. 6  shows the arrangement of three plate groups having first plates  13 , second plates  14 , and third plates  15 , whereby of third plates  15  only passages  22  can be seen in each case. 
         [0052]    The two first and second plates  13 ,  14  lie against one another with their circumferential edges. Passages  7 ,  9  of the first plate are embossed forwards, whereby passages  22  of the third plate are embossed toward the back. The backward protruding passages or cups of second plate  14 , which cannot be seen in this perspective view, however, lie between these. It is clear, however, that the passages or cups  22  are at twice the height as the refrigerant cups.  FIG. 4  shows that the backward protruding cups  22  of third plate  15  are approximately at twice the height as the cups of first and second plate  13 ,  14 . 
         [0053]    It is also evident that the channel-forming structures of first plate  13 ,  16  proceeding from cups  7 ,  9  expand to approximately half the width of the first plate and in the area of opening  8  of the first plate have a gusset-like recess, so that in this area soldering of first plate  13  to the cup of third plate  15  may be provided. 
         [0054]      FIGS. 7 to 10  show the design of the first, second, or third plates  13 ,  14 ,  15  in two different variants, whereby in  FIGS. 7 and 8  the cups of first, second, and third plate  13 ,  14 ,  15  have the same depth or length, and in the exemplary embodiment of  FIGS. 9 and 10  cup  22  of third plate  15  has twice the depth of cups  7 ,  9  of first and second plate  13 ,  14 , whereby the first plate in the connection area of the third plate has no cup. Here, cups  7 ,  9  have the same depth as cup  24  of third plate  15 . It can be seen in  FIG. 9  that cup  7  and cup  9  have approximately only half the depth of cup  22  of third plate  15 . 
         [0055]      FIGS. 11 to 14  show cuts through the plate groups, whereby  FIGS. 11 and 12  show a cut through a plate group, which occurs in  FIG. 7  or  9  approximately in the middle of cups  7 ,  9  along line I-I, whereby this cut is made below cup  22  or  24 . 
         [0056]      FIG. 11  shows the arrangement of three plate groups having a first plate  13 , a second plate  14 , and a third plate  15  in a side view from which the second plate and the third plate can be recognized. Three such plate groups are shown with connection of the cups of the plates to one another. It can be seen that cups  7 ,  9  of the first plate have substantially the same depth as cups  18 ,  19  of the second plate. The cup of the third plate cannot be seen. Here, only an area of channel-forming structure  15  of the third plate is visible. 
         [0057]      FIG. 12  shows the same configuration of plates  13 ,  14 ,  15  as  FIG. 11 , but only from the other side, so that in  FIG. 12  the view is of first plate  13  as it were.  FIGS. 13 and 14  show a cut through a plate arrangement according to  FIG. 9  but at the height of the middle of passage  22  according to line II-II. 
         [0058]    This cut occurs somewhat further above in comparison with the cut indicated by line I-I, so that now the three plate groups are cut and shown in the middle of cup  22 . It can be clearly seen that cup  22  has twice the depth in comparison with cups  19  or  9  or  7  and  18 . Therefore no cup is arranged on the side opposite to cup  22  of plate  13 , so that the far end of cup  22  on the opposite side touches first plate  13  directly without interconnection of a corresponding cup. 
         [0059]    The absence of the cup on the sides of first plate  13  can be clearly seen in  FIG. 14 . 
         [0060]      FIGS. 15 and 16  show a cut through the arrangement of the plate groups according to  FIG. 6 , whereby the plate groups are cut in the center of the plates.  FIG. 6  shows a section of  FIG. 5  with respect to an area in the middle of a plate group. 
         [0061]      FIG. 15  shows the plate group from the side of first plate  13 , provided on the back with plate  14 , and onto the right side of which a plate  15  is again applied. First flow path  30  is formed between channel-like structure  31  of plate  13  and the channel-like structure  32  of plate  14 . Second flow path  33  is formed by channel-like structure  34  of plate  13  and planar plate surface  35  of the second plate. The second plate is preferably planar in this region but can also assume a specific structure. 
         [0062]    Third flow path  36  is formed by wall  35  of the second plate and channel-like structure  37  of third plate  15 . 
         [0063]    As can be seen in  FIG. 16 , first flow path  30  is arranged between the first and second plate. Adjacent thereto, second flow path  33  is also arranged between the first and second plate, whereby third flow path  36  is arranged between the second plate and third plate. The expansion of the first flow path corresponds substantially to the expansion of the second flow path plus the expansion of the third flow path plus the thickness of the wall of the second plate. 
         [0064]    In the present exemplary embodiment of  FIGS. 9 and 10  with extended passage  22  of plate  15 , it can be seen that section  99  in plate  13  is greater than the diameter of passage  22 , so that upon soldering of two plate groups  13 ,  14 ,  15  one on top of the other, passage  22  does not come into contact with plate  13  but with plate  14 , onto which plate  15  is soldered from the other side. As a result, in the case of leakage between the soldered plates in the area of passage  22 , it occurs only between the channel between plates  14  and  15  and the outer area, without the other channels being involved and adversely affected. 
         [0065]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.