Patent Publication Number: US-10782074-B2

Title: Heat exchanger with a cooling medium bar

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is claiming the benefit, under 35 U.S. C. 119(e), of the U.S. provisional patent application which was granted Ser. No. 62/574,853 and filed on Oct. 20, 2017, the entire disclosure of which is hereby incorporated by reference. 
    
    
     BACKGROUND 
     The invention relates to a heat exchanger. More particularly, the invention relates to a bar and plate type heat exchanger. 
     Heat exchangers of the bar and plate variety are known. Such heat exchangers may be exposed to high thermal and mechanical loads caused by thermal and/or pressure cycles. These conditions can lead to stresses. Over time, such stresses can result in the formation of cracks in the areas where the bars and plates are joined together. The formation of cracks in such areas can lead to leaks in the heat exchanger and a decrease in the efficiency of the heat exchanger. 
     It would be desirable to provide a heat exchanger that can resist the formation of cracks in the areas where its components are joined together when it is exposed to the conditions described above. 
     BRIEF SUMMARY 
     Embodiments of a heat exchanger are provided. In an embodiment, the heat exchanger comprises one or more hot medium flow regions and one or more cooling medium flow regions. Hot medium bars border the one or more hot medium flow regions and cooling medium bars border the one or more cooling medium flow regions. At least one cooling medium bar of the cooling medium bars is joined to a pair of partition sheets. The at least one cooling medium bar comprises a base, a first leg, and a second leg. The first leg and the second leg each extend from the base. A cavity is provided between the first leg and the second leg. The cavity is in fluid communication with a first cooling medium flow region of the one or more cooling medium flow regions via an opening provided between the first leg and the second leg. The cavity is at least partially defined by an inner end portion adjoining a first wall portion and a second wall portion. The inner end portion has an inner end portion curved surface. The first wall portion has a first wall portion planar surface. The second wall portion has a second wall portion planar surface. The first wall portion adjoins a third wall portion and the second wall portion adjoins a fourth wall portion. The third wall portion has a third wall portion curved surface and the fourth wall portion has a fourth wall portion curved surface. The third wall portion adjoins a fifth wall portion and the fourth wall portion adjoins a sixth wall portion. The fifth wall portion and the sixth wall portion at least partially define the opening. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The above, as well as other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which: 
         FIG. 1  is a perspective view of a heat exchanger in accordance with the invention; 
         FIG. 2  is an enlarged partial perspective view showing selected portions of the heat exchanger of  FIG. 1 ; 
         FIG. 3  is an enlarged view of a portion of  FIG. 2 ; 
         FIG. 4  is an enlarged view of a portion of  FIG. 3 ; and 
         FIG. 5  is a front view of an embodiment of a cooling medium bar utilized in the heat exchanger of FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific assemblies, devices, and features illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific dimensions, directions, or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless expressly stated otherwise. Also, although they may not be, like elements found in the aforementioned embodiments may be referred to with like identifiers within this section of the application. 
     Embodiments of a heat exchanger  10  are described herein and are illustrated in  FIGS. 1-5 . The heat exchanger  10  may have applications in a vehicle as a radiator, charge-air cooler, or oil cooler. However, it should also be appreciated that the heat exchanger  10  may have other applications. 
     The heat exchanger  10  comprises one or more hot medium flow regions  12 ,  12   a ,  12   b ,  12   c . Preferably, when a plurality of hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  are provided, the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  are in a spaced apart and parallel relationship with each other. When the heat exchanger  10  is in use, a hot medium or fluid flows in each hot medium flow region  12 ,  12   a ,  12   b ,  12   c . The hot medium may be a liquid such as, for example, a coolant or oil or a gas such as, for example, air. 
     The heat exchanger  10  utilizes a cooling medium to cool the hot medium. Preferably, the cooling medium is air. However, it should be appreciated that the cooling medium may be another fluid. The cooling medium flows in one or more cooling medium flow regions  14 ,  14   a ,  14   b . Preferably, when a plurality of cooling medium flow regions  14 ,  14   a ,  14   b  are provided, the cooling medium flow regions  14 ,  14   a ,  14   b  are in a spaced apart and parallel relationship with each other. 
     In certain embodiments, the heat exchanger  10  may be of the one-pass variety. In one such embodiment, the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  and cooling medium flow regions  14 ,  14   a ,  14   b  are positioned between an inlet tank  100  and an outlet tank  102 . In this embodiment, the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  extend between and are in fluid communication with the inlet tank  100  and the outlet tank  102 . The hot medium is received in the inlet tank  100  via an inlet  104 . The inlet tank  100  is in fluid communication with the inlet  104 . The inlet  104  is provided to receive the hot medium and direct the hot medium to the inlet tank  100 . The inlet tank  100  directs the hot medium to the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c . From the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c , the hot medium is directed to the outlet tank  102 . The outlet tank  102  is in fluid communication with an outlet  106 . The outlet  106  is provided to receive the hot medium from the outlet tank  102  and direct the hot medium away from the outlet tank  102 . 
     In other embodiments (not depicted), the heat exchanger may be of the two-pass variety. In one such embodiment, the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  and cooling medium flow regions  14 ,  14   a ,  14   b  may be positioned between a tank (not depicted) and a manifold (not depicted). In this embodiment, the tank may comprise an inlet and an outlet. Also, in this embodiment, the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  extend between and are in fluid communication with the tank and the manifold. The tank receives the hot medium at the inlet and directs the hot medium to the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c . From the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c , the hot medium is received by the manifold. After the hot medium has been received by the manifold, the hot medium is directed back through the heat exchanger to the outlet of the tank. 
     Preferably, the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  and cooling medium flow regions  14 ,  14   a ,  14   b  are in a perpendicular relationship with each other. The orientation of the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  and cooling medium flow regions  14 ,  14   a ,  14   b  allows the hot medium to flow in a first direction and the cooling medium to flow in a second direction. Preferably, the first direction and the second direction are different. 
     Further, in some embodiments, the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  and cooling medium flow regions  14 ,  14   a ,  14   b  are provided in an alternating arrangement. For example, when the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  comprise a first hot medium flow region  12   a  and a second hot flow medium flow region  12   b , a first cooling medium flow region  14   a  is provided between the first hot medium flow region  12   a  and the second hot flow medium flow region  12   b . In this embodiment, the first hot medium flow region  12   a  and the second hot flow medium flow region  12   b  are in a spaced apart and parallel relationship with each other. 
     As illustrated best in  FIGS. 3-4 , a partition sheet  16 ,  16   a  separates a hot medium flow region  12 ,  12   a ,  12   b ,  12   c  from a cooling medium flow region  14 ,  14   a ,  14   b . Preferably, each partition sheet  16 ,  16   a  is relatively thin and comprises aluminum or an aluminum alloy. In an embodiment, one or more of the partition sheets  16 ,  16   a  also comprise a coating of brazing material on each major surface thereof. Preferably, each partition sheet  16 ,  16   a  comprises a coating of brazing material on each major surface thereof. The coating of brazing material is utilized to join each partition sheet  16 ,  16   a  to a hot medium bar  18  and a cooling medium bar  20  during a brazing process. 
     An end sheet (not depicted) is located at each end of the heat exchanger  10 . Each end sheet is joined to a partition sheet  16 ,  16   a . In an embodiment, the end sheets are each of a thickness that is greater than the thickness of the partition sheets  16 ,  16   a . The end sheets may each comprise aluminum or an aluminum alloy. 
     It is preferred that one or more hot medium bars  18  border each hot medium flow region  12 ,  12   a ,  12   b ,  12   c . Preferably, a pair of hot medium bars  18  border each hot medium flow region  12 ,  12   a ,  12   b ,  12   c  on opposite sides thereof. In an embodiment, the hot medium flow regions  12 ,  12   a ,  12   b ,  12   c  are also bordered by a pair of partition sheets  16 ,  16   a . In this embodiment, each hot medium bar  18  may be joined to a pair of partition sheets  16 ,  16   a . The one or more hot medium bars  18  assist in spacing the partition sheets  16 ,  16   a  from each other. 
     Each hot medium bar  18  may be of solid construction and may comprise aluminum or an aluminum alloy. In an embodiment, which is illustrated best in  FIG. 3 , one or more of the one or more hot medium bars  18  have a generally rectangular portion attached to a tapered portion. The tapered portion extends toward a respective hot medium flow region  12 ,  12   a ,  12   b ,  12   c  and may be of a generally triangular shape. Preferably, each hot medium bar  18  is configured in a similar manner and as described above. However, the hot medium bars  18  may be of any configuration known in the art. 
     It is preferred that a hot medium fin  22  is located within each hot medium flow region  12 ,  12   a ,  12   b ,  12   c . The hot medium fins  22  help support the partition sheets  16 ,  16   a  and increase the heat transfer rate between the cooling medium and the hot medium. Each hot medium fin  22  may comprise aluminum or an aluminum alloy. Preferably, each hot medium fin  22  is corrugated. However, the hot medium fins may be of another configuration known in the art. 
     It is preferred that one or more cooling medium bars  20  border each cooling medium flow region  14 ,  14   a ,  14   b . Preferably, a pair of cooling medium bars  20  border each cooling medium flow region  14 ,  14   a ,  14   b  on opposite sides thereof. Each cooling medium bar  20  may comprise aluminum or an aluminum alloy. It is preferred that each cooling medium flow region  14 ,  14   a ,  14   b  is also bordered by a pair of partition sheets  16 ,  16   a . In an embodiment, each cooling medium bar  20  may be joined to a pair of partition sheets  16 ,  16   a . The cooling medium bars  20  assist in spacing the partition sheets  16 ,  16   a  from each other. 
     For describing certain embodiments of the heat exchanger  10 , only the cooling medium bar  20  illustrated in  FIGS. 4-5  will be described below. It should be appreciated that the embodiments of the cooling medium bar  20  described below could be utilized to configure the remaining cooling medium bars in the heat exchanger  10 . In some embodiments, it may be preferred each cooling medium bar  20  in the heat exchanger  10  is similarly configured. 
     Also, the cooling medium bar  20  illustrated in  FIGS. 4-5  will be described with reference to the first cooling medium flow region  14   a . Thus, only the first cooling medium flow region  14   a  will be described below. It should be appreciated that the embodiments of the first cooling medium flow region  14   a  described below could be utilized to configure the remaining cooling medium flow regions  14 ,  14   b  in the heat exchanger  10 . In some embodiments, it may be preferred that each cooling medium flow region  14 ,  14   a ,  14   b  is similarly configured. 
     Referring now to  FIG. 4 , the cooling medium bar  20  borders the first cooling medium flow region  14   a . The cooling medium bar  20  is joined to a pair of partition sheets  16 ,  16   a . As illustrated, the cooling medium bar  20  comprises a base  24 , a first leg  26 , and a second leg  28 . In some embodiments, the base  24  comprises a first surface  96  and a second surface  98 . Preferably, the first surfaces  96  and the second surface  98  are provided in a parallel relationship with each other. The first leg  26  and the second leg  28  each extend from the base  24 . Preferably, the first leg  26  and the second leg  28  extend in the same direction and toward the first cooling medium flow region  14   a.    
     As illustrated, the first leg  26  and the second leg  28  may be similarly configured. Thus, for describing certain embodiments, only the portions  30 ,  32  of the first leg  26  will be referred to below. It should be appreciated that the second leg  28  may comprise portions that are not explicitly mentioned below and are configured in a manner which is similar to the portions  30 ,  32  of the first leg  26  described below. 
     Referring now to  FIGS. 4-5 , in an embodiment, the first leg  26  comprises a first portion  30  and a second portion  32 . In this embodiment, the first portion  30  is attached to the base  24  on an end thereof and the second portion  32  on an opposite end thereof. It is preferred that the first portion  30  gradually decreases in thickness toward the first cooling medium flow region  14   a  and that the second portion  32  has a constant thickness. In an embodiment, the second portion  32  comprises an inner surface  34  and a curved outer surface  36 . The inner surface  34  is at least partially defined by a third wall portion  38 . As illustrated best in  FIG. 4 , the curved outer surface  36  faces a first surface  40  of a partition sheet  16 . Preferably, the curved outer surface  36  is joined to the first surface  40  of the first partition plate  16  by a joint  42   a . Preferably, the joint  42   a  is formed by a brazing process. However, it should be appreciated that other process may be utilized to form the joint. In certain embodiments, it may be preferred that the second portion  32  also comprises a transition surface  44 . The transition surface  44  may be curved or sharply defined. In an embodiment, the transition surface  44  separates the curved outer surface  36  from another portion  46  of the first leg  26 . Preferably, the transition surface  44  separates the curved outer surface  36  from a fifth wall portion  46 . 
     A cavity  48  is provided between the first leg  26  and the second leg  28 . The cavity  48  is in fluid communication with the first cooling medium flow region  14   a  via an opening  50  provided between the first leg  26  and the second leg  28 . A first portion of the cavity  48  may gradually increase in thickness from an inner end portion  52  toward the opening  50  and a second portion of the cavity  48 , adjacent the opening  50 , may gradually increase in thickness from the opening  50  toward the inner end portion  52 . The second portion of the cavity  48  separates the first portion from the opening  50 . 
     The cavity  48  is at least partially defined by the inner end portion  52 . The inner end portion  52  adjoins a first wall portion  54  and a second wall portion  56 . The inner end portion  52  has an inner end portion curved surface  58 . The inner end portion curved surface  58  comprises a first radius of curvature  60 . 
     The first wall portion  54  has a first wall portion planar surface  62 . The second wall portion  56  has a second wall portion planar surface  64 . Preferably, the first wall portion planar surface  62  and the second wall portion planar surface  64  extend away from the inner end portion curved surface  58  toward the first cooling medium flow region  14   a . Further, in some embodiments, the first wall portion planar surface  62  and the second wall portion planar surface  64  diverge from each other. Preferably, the first wall portion planar surface  62  and the second wall portion planar surface  64  diverge from each other in a direction toward the opening  50 . 
     The first wall portion  54  adjoins the third wall portion  38  and the second wall portion  56  adjoins a fourth wall portion  66 . The third wall portion  38  has a third wall portion curved surface  68  and the fourth wall portion  66  has a fourth wall portion curved surface  70 . The third wall portion curved surface  68  and the fourth wall portion curved surface  70  converge toward each other in a direction toward the opening  50 . Further, the third wall portion curved surface  68  and the fourth wall portion curved surface  70  each comprise a radius of curvature  72 ,  72   a . Preferably, the radius of curvature  72  for the third wall portion curved surface  68  and the radius of curvature  72   a  for the fourth wall portion curved surface  70  are equal to each other. In an embodiment, the first radius of curvature  60  is less than the radius of curvature  72  for the third wall portion curved surface  68  and the radius of curvature  72   a  for the fourth wall portion curved surface  70 . 
     The third wall portion  38  adjoins the fifth wall portion  46  and the fourth wall portion  66  adjoins a sixth wall portion  74 . The fifth wall portion  46  and the sixth wall portion  74  at least partially define the opening  50 . In certain embodiments, the fifth wall portion  46  comprises a fifth wall portion curved surface  76  and the sixth wall portion  74  comprises a sixth wall portion curved surface  78 . The fifth wall portion curved surface  76  is attached to the third wall portion  38  and the sixth wall portion curved surface  78  is attached to the fourth wall portion  66 . The fifth wall portion  46  may also comprise a fifth wall portion planar surface  80  and the sixth wall portion  74  may also comprises a sixth wall portion planar surface  82 . When provided, the fifth wall portion planar surface  80  is attached to the fifth wall portion curved surface  76  and the sixth wall portion planar surface  82  is attached to the sixth wall portion curved surface  78 . In this embodiment, the fifth wall portion planar surface  80  and the sixth wall portion planar surface  82  are separated by the opening  50  and in a parallel relationship with each other. 
     Referring back to  FIG. 3 , it is preferred that a cooling medium fin  84  is located within each cooling medium flow region  14 ,  14   a ,  14   b . The cooling medium fins  84  help support the partition sheets  16 ,  16   a  and increase the heat transfer rate between the cooling medium and the hot medium. The cooling medium fins  84  may comprise aluminum or an aluminum alloy. The cooling medium fins  84  are preferably corrugated. However, the cooling medium fins may be of any configuration known in the art. 
     In some embodiments, an end  86  of the first leg  26  and an end  88  of the second leg  28  are spaced apart from the fin  84 . In other embodiments, like the one illustrated in  FIG. 4 , the end  86  of the first leg  26  and the end  88  of the second leg  28  abut a side wall  90  of the fin  84 . In this embodiment, the configuration of the cooling medium bar  20  provides a space  92  that separates an end  94  of the fin  84  from the joint  42 , which prevents the end  94  of the fin  84  from interfering with the formation of the joint  42 . 
     Advantageously, the embodiments of the heat exchanger  10  described above allow the cooling medium bar  20  to exhibit flexibility and elasticity in response to the thermal and mechanical loads experienced by the heat exchanger  10 . More particularly, the first leg  26  and the second leg  28  are configured and intended to elastically deform in response to the thermal and mechanical loads experienced by the heat exchanger  10 . The flexibility and elasticity of the legs  26 ,  28 , which is provided by the features described above, reduces the stress experienced by the joints  42 ,  42   a  between the partition sheets  16 ,  16   a  and the cooling medium bar  20  attached thereto. As such stresses can result in the formation of cracks in the joints  42 ,  42   a  and/or the partition sheets  16 ,  16   a  and said cracks may result in leaks in the heat exchanger, the increased flexibility and elasticity exhibited by the cooling medium bar  20  assists in maintaining the efficiency of the heat exchanger  10 . 
     From the foregoing detailed description, it will be apparent that various modifications, additions, and other alternative embodiments are possible without departing from the true scope and spirit. The embodiments discussed herein were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to use the invention in various embodiments and with various modifications as are suited to the particular use contemplated. As should be appreciated, all such modifications and variations are within the scope of the invention.