Abstract:
A heat exchanger, with a core region having a plurality of tube bundles through which a fluid flows in series is provided with at least one specially designed header composed of two half shells. The specially designed header deflects the fluid stream between two successive tube bundles in opposite directions, with the supply and discharge of the fluid to and from the core region through the header. The resulting heat exchanger is structurally simple, having a minimum number of components to be mounted.

Description:
[0001]     This application is a national phase application of International application PCT/EP2004/009111, filed Aug. 13, 2004 and claims the priority of German application No. 103 39 072.3, filed Aug. 26, 2003, the disclosure of which are expressly incorporated by reference herein. 
     
    
     BACKGROUND AND SUMMARY OF THE INVENTION  
       [0002]     The invention relates to a heat exchanger for a fluid.  
         [0003]     Heat exchangers are used, for example, in the air conditioning systems of motor vehicles, in which, via the multiplicity of tubes and large surface resulting from these, heat transmission between the fluid circulating in the tubes and the outside air is carried out. The various applications may involve both changes in temperature of the fluid and changes in heat due to phase transition of the fluid.  
         [0004]     Such a heat exchanger is known, for example, from DE 198 30 329 A1. The heat exchanger described in this publication is a coolant or refrigerant condenser with a core region having a multiplicity of tubes which extend horizontally and are arranged parallel to one a meandering manner, the deflection of the fluid when it emerges from one of the tubes or tube bundles and when it reenters the next tube or tube bundle in the opposite direction taking place in headers arranged on both end faces of the tubes and open with respect to these. The inflow and outflow of the coolant or refrigerant into and out of the heat exchanger take place via a connecting block which is connected via pipelines to the first tube where the fluid enters the heat exchanger and to the last tube when the fluid emerges from the heat exchanger.  
         [0005]     An object of the invention is to provide a heat exchanger which is structurally simple and having a minimum number of components to be mounted on the heat exchanger.  
         [0006]     To achieve this object, in a generic heat exchanger, there is provided a heat exchanger in which at least one header has in the longitudinal direction a partition which subdivides the header into a first region open to the tubes and connecting these and a second region which is a bypass with respect to the tube bundles.  
         [0007]     With the at least one header being divided, this gives rise not only to the region in which the control and deflection of the fluid stream meandering through the serial tube bundles take place, but also to a second region which forms a bypass with respect to the tube bundles. This arrangement makes it possible to control the entire fluid stream within the heat exchanger solely by the tubes of the core region and the headers in each case arranged on the end faces of the tubes. Since the header or headers assumes or assume the function of supplies and discharges with respect to the core region of the heat exchanger, further functional components in this respect are unnecessary.  
         [0008]     In an advantageous development, a block having the supply and discharges with respect to the heat exchanger is arranged at one end of the header. Via this block, the fluid is supplied to the heat exchanger and, after being routed to the individual tubes or tube bundles from the corresponding regions in the header, is discharged from the heat exchanger again.  
         [0009]     Also advantageously, the longitudinal partition of the header has at least two passage orifices through which the fluid can be conducted from the conducting region of the header through the passage orifices and via the deflection region of the header and be returned in the opposite direction. Depending on the choice of position of the passage orifices, fluid exchange between the conducting region of the header and the tubes can take place at a largely freely selectable point over the length of the header, with the result that the flow path of fluid through the tube bundles can also be influenced.  
         [0010]     In this case, a connection to a tube bundle can be formed by at least one first of the passage orifices in the longitudinal partition and a connection to the junctions of the block can be formed by at least one second of the passage orifices. That is to say, the fluid stream can be routed from the block into the deflection region of the header, then conducted through the tube system in a meandering manner and be led back to the block via the conducting region of the header. The fluid stream can also be routed in the same way in the opposite direction.  
         [0011]     In this case, it is beneficial to arrange the block having the supplies and discharges fixedly on the header, so that the entire heat exchanger can be mounted in one piece without further additional components.  
         [0012]     It is expedient, further, for the header to be composed of an open half shell and of a closed half shell which can be connected fixedly in a simple way.  
         [0013]     In a first alternative design, the second region is open over the length of the header, so that the fluid stream can be conducted over the entire length of the header between the block and, selectively, the starting point of the end point of the fluid stream in the heat exchanger.  
         [0014]     In the second alternative embodiment, that region of the header which faces away from the tubes is subdivided into two separate regions, with the result that at least two independent fluid streams can be routed in the region. By means of this configuration, there is the possibility of introducing and discharging the fluid stream into and out of the system of tubes or tube bundles at two different points and of being able to route the fluid streams resulting from these in the second region of the header completely independently of one another.  
         [0015]     In an advantageous design of the second alternative, the region is subdivided into two ducts arranged in parallel. Thus, in a simple production process, a header can be produced, by means of which a plurality of introductions and discharges of the fluid stream into and out of the conducting region of the header can be carried out at a freely selectable point, without the inflow and the return flow of the fluid stream from the block being impaired.  
         [0016]     In an expedient development, in this case, the closed half shell is designed in a structurally simple way as a double chamber.  
         [0017]     In the invention, taken as a whole, the headers are advantageously designed to be pushed into a guide rail for holding the heat exchanger. One of the criteria for the advantageous configuration of the heat exchanger is to limit this to a minimum number of necessary components and to fulfill all the functions by means of these necessary components.  
         [0018]     In an expedient design of the invention, the heat exchanger is an air conditioning condenser, in which a coolant or refrigerant is transferred from a gaseous phase into a liquid phase, with heat being discharged into the ambient air.  
         [0019]     Alternatively, the heat exchanger may also be designed as a gas cooler.  
         [0020]     In the case of an air conditioning condenser, it is particularly advantageous to design the last pass through one of the tubes or tube bundles as a supercooling stage, in each case, in the second alternative design of the header, the supercooling stage does not have to be arranged on one of the end pieces of the header, but may be arranged freely over the entire length of the header.  
         [0021]     Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings for example. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]      FIG. 1  shows an overall view of a the heat exchanger in accordance with an embodiment of the present invention,  
         [0023]      FIG. 2  shows the heat exchanger according to the embodiment in  FIG. 1  in a partially cut away illustration and partially exploded illustration,  
         [0024]      FIG. 3  shows a cross-sectional illustration of the header according to the version in  FIG. 2 ,  
         [0025]      FIG. 4  shows an alternative embodiment of the heat exchanger in a partially cut away illustration and partially exploded illustration,  
         [0026]      FIG. 5  shows a cross-sectional illustration of the header according to the embodiment in  FIG. 4 . 
     
    
     DETAILED DESCRIPTION  
       [0027]      FIG. 1  shows a heat exchanger which is designed as an air conditioning condenser  10  which is integrated into a coolant or refrigerant cycle, not illustrated, of a conventional air conditioning system of a motor vehicle.  
         [0028]     The cooling or refrigerating fluid is supplied in gas form in the air conditioning condenser  10  and is condensed into its liquid phase, with heat being discharged. For this purpose the air conditioning condenser  10  has a core region  12  with a multiplicity of tubes which are arranged horizontally and in parallel and over the large overall surface of which the heat released during the condensing or cooling of the fluid can be discharged into the ambient air flowing around the tubes.  
         [0029]     The air conditioning condenser  10  has, in addition to the core region  12  of the individual tubes, two collecting containers  14 ,  16  which are arranged in each case on the end faces of the individual tubes of the core region  12  and which are connected to the tubes. The cooling or refrigerating fluid is supplied to and discharged from the air conditioning condenser  10  via the block screw connection  18 . For this purpose, the block screw connection  18  has a first junction  20  for the supply and a second junction  21  for the discharge of the fluid. The junctions for the supplies and discharges may also be interchanged as a function of the flow routing of the fluid.  
         [0030]     The individual tubes of the core region  12  are connected on the end faces to orifices on the collecting containers  14 ,  16 , so that the fluid circulating in the air conditioning condenser can be conducted via the collecting containers from one individual tube to the next individual tube.  
         [0031]     In the conventional design, the air conditioning condenser  10  has, furthermore, a filling valve  22  and a drier bottle  24  for drying the circulating fluid by means of granulate contained in the drier bottle. Furthermore, the drier bottle  24  forms a buffer in the case of possible overfilling.  
         [0032]     The block screw connection  18  may be arranged on the collecting container  16 , in which case the routing of the fluid may take place via the collecting container  16  in the way outlined below, so that, apart from the block screw connection  18 , there is no need for any further pipework with the corresponding additional components.  
         [0033]     With the exception of the necessary junctions ( 20 ,  21 ) for the supply and discharge of the block screw connection  18 , no further components are necessary for the functioning and for the fastening of the air conditioning condenser  10 . By virtue of this compact type of construction of the air conditioning condenser  10 , the latter can be held, for example, by the collecting containers  14 ,  16  being pushed into correspondingly designed rails, for example on the cooling module.  
         [0034]      FIG. 2  shows the collecting container  16  in a partially exploded illustration. The collecting container  16  is designed as a double tube with the separate regions  16   a  and  16   b , partitions  26   a  to  26   e  being arranged transversely to the longitudinal direction of the collecting container  16  and parallel to the tubes of the core region  12  in addition to the separation in the longitudinal direction of the collecting container  16 .  
         [0035]     The longitudinal division of the collecting container  16  and the partitions  26  serve for routing the fluid stream of the coolant or refrigerant in a meandering manner through the tube system in the core region  12  of the air conditioning condenser  10 . Slots  28  are shown in the part region  16   a  of the collecting container  16 , each slot being connected to a tube of the core region  12 .  
         [0036]     By means of the partitions  26   a  to  26   d , the individual tubes issuing in each case between two partitions into the region  16   a  of the collecting container form a tube bundle in which the fluid in each case flows codirectionally. The part region  16   a  of the collecting container  16  deflects the fluid stream coming from one tube bundle into the tube bundle following in series, so that the fluid stream flows through the successive tube bundles in each case in the opposite direction. The corresponding region, not illustrated, of the second collecting container  14  is constructed in a similar way to the part region  16   a  of the collecting container and with the same function.  
         [0037]     The fluid stream (illustrated by broken lines) enters the air conditioning condenser  10  via the supply line  20  of the block screw connection  18 . The fluid stream is conducted through a passage orifice  30 , provided in the partition between the region  16   a  and  16   b  of the collecting container  16 , into the region  16   b  of the collecting container (arrow A) and in this part region rises upward (arrow B) as far as a second passage orifice  32  arranged at the upper end of the collecting container  16 , transition taking place back into the region  16   b  of the collecting container.  
         [0038]     Via the orifices  28   a  which are arranged in the portion of the part region  16   a  between the partitions  26   a  and  26   b , the fluid stream enters the tubes which form a tube bundle and are connected to the orifices  28   a  (arrow C).  
         [0039]     After passing through these tubes and being deflected in the collecting container  14 , not shown, the fluid stream is returned in the next tube bundle to the collecting container  16  (arrow D).  
         [0040]     The meandering throughflow through the tubes of the core region  12  takes place in a similar way in the next tube bundles (arrow E, F).  
         [0041]     The number of individual tubes forming a bundle can be determined by the positioning of the partition  26  in adaption to the actual application.  
         [0042]     After flowing through all the tube bundles provided, the fluid stream is led out of the air conditioning condenser by the discharge line  21  of the block screw connection  18  (arrow G).  
         [0043]     The two part regions  16   a ,  16   b  of the collecting container  16  which are designed as double tube halves are produced separately from aluminum and are subsequently soldered. The block screw connection  18  is also connected fixedly to the part region  16   a  by soldering. The partitions  26   a  and  26   e  arranged on the end faces of the collecting container  16  in each case cover the entire cross section of the collecting container  16 , so that an emergence of fluid is prevented. The last portion of the throughflow through the core region  12  (arrow F) is designed as a supercooling region in which the fluid which is already condensed out and is in the liquid phase experiences a lowering of temperature to a temperature below the evaporation temperature.  
         [0044]     According to the cross section, shown in  FIG. 3 , of the collecting container  16 , the latter is composed of a part region  16   a  designed as an open half shell and of a part region  16   b  designed as a closed half shell, these two part regions being connected to one another by soldering. The part region  16   b  fulfills the function of a supply line to the core region of the air conditioning condenser, while the part region  16   a  serves for controlling and steering the fluid stream when it emerges from a tube bundle or when it subsequently re-enters the next following tube bundle. In this illustration, the partition  16   c  can be seen, which is an integral part of the part region  16   b  of closed design and which separates the part regions  16   a  and  16   b  over the entire length of the collecting container  16 , with the exception of the passage orifices  30 ,  32  ( FIG. 2 ). The cross section according to  FIG. 3  lies in the lower portion of the header  16 .  FIG. 3  shows both the block screw connection  18  and the partition  26   e  which sealingly closes off the header  16  on the lower end face of the latter and passes completely through the two part regions  16   a ,  16   b.    
         [0045]      FIG. 4  shows an air conditioning condenser, in which, by means of a differently constructed collecting container  16 , the flow of the fluid can be varied, as compared with the first alternative described, in such a way that the tube bundles follow one another such that the last throughflow tube bundle is not located on the bottom of the collecting container  16 , but in a position vertically above the latter. The supercooling region of the fluid can thereby be placed on a largely freely selectable tube bundle when the outside temperature conditions make this necessary. Details described separately with reference to  FIG. 4  correspond to those of the design alternatives described above.  
         [0046]     Owing to the simple design of the air conditioning condenser with the two collecting containers  16 ,  14  and with the block screw connection  18  arranged on the foot side of the header  16 , no changes to these are necessary.  
         [0047]     The changed fluid flow is possible solely as a result of a structural change in the part region  16   b  of the collecting container  16 . According to the variant described here, this part region is designed as a double tube, and the fluid stream can be routed in a crossed manner in the double tube without any impairments.  
         [0048]     As illustrated in  FIG. 4 , the supply and outlet orifices  20 ,  21  of the block screw connection are controlled conversely to the way illustrated in  FIG. 2 , so that the fluid stream is conducted (arrow H) via the junction of the supply line  20  into the part region  16   a  and from there into the lowermost tube bundle, delimited by the partitions  27   f  and  27   g , of the core region  12 . In this embodiment, the fluid is conveyed upward in the core region and is returned again in the opposite direction in the adjacent tube bundle (arrow I). After running through the tube bundle according to the arrow I, the fluid stream passes through a first of four passage orifices  33   a  into a first duct  17   a  of the region  16   a , designed as a double tube half, of the collecting container  16  and is conveyed in this to the upper end of the header  16  to the second passage orifice  33   b  (arrow J).  
         [0049]     After the passage orifice  33   b , the fluid stream passes into the region of the part region  16   a  of the header  16  between the partitions  27   a  and  27   b  and from there into the tube bundle arranged in this region (arrow K). From this tube bundle arranged in the upper portion of the core region  12 , the fluid stream is routed in the way stated above through three tube bundles arranged in series (arrows L, M and N) and then passes, between the two partitions  27   c ,  27   d , through the third passage orifice  33   c  into the second chamber  17   b  of the region  16   b , designed as a double tube, of the header  16 . The fluid stream is routed (arrow O) through this chamber  17   b  to the lower end of the header  16  and is conducted via the fourth passage orifice  33   d  from the part region  16   b  into the part region  16   a  and from there to the outlet orifice  21  of the block screw connection  18 .  
         [0050]     As is evident from this application according to  FIG. 4 , the last throughflow tube bundle of the core region  12  of the air conditioning condenser  10  is located approximately in the middle of the air conditioning condenser in this alternative embodiment (arrow N). Since this last pass through a tube bundle constitutes the supercooling stage, if such is incorporated, it should be ensured that this region is not exposed to any heat radiation from other assemblies of the air conditioning system or of the motor vehicle.  
         [0051]     In a conventionally arranged air conditioning system, the charge air cooler is often adjacent to the lower region of the air conditioning condenser, so that, in the case of a high engine power, high heat radiation occurs which makes it necessary to change the location of the supercooling stage.  
         [0052]     It is possible to change the location of the supercooling stage, without additional structural measures, by means of the header  16  designed according to  FIG. 4 .  
         [0053]     As can be seen from  FIG. 4 , furthermore, the fluid stream, by being routed crosswise in the chambers  17   a  and  17   b , can be routed through the core region in such a way that the position of the supercooling stage can be as far as possible selected freely.  
         [0054]      FIG. 5  shows a cross section of the header  16  which again is constructed from two half shells  16  and  16   a  which consist of aluminum and are soldered. The region  16   a  has an unchanged design, as compared with the first variant, and again serves, above all, for steering the fluid stream from one tube bundle to the next following tube bundle. The part region  16   b  designed as a double tube has a chamber  17   a , via which the fluid, after the first two passes through the two lower tube bundles (arrow H, I according to  FIG. 4 ), is transported into the upper region of the header (arrow J according to  FIG. 4 ).  
         [0055]     After the last pass through a tube bundle, usually the supercooling stage, the chamber  17   b  receives the fluid (arrow N according to  FIG. 4 ) and routes the supercooled fluid into the lower region of the header  16 , from where the fluid leaves the air conditioning condenser via the block screw connection  18 .  
         [0056]     The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.