Patent Publication Number: US-2018051941-A1

Title: Heat exchanger with removable core assembly

Description:
BACKGROUND 
     The present invention relates to heat exchanger arrangements, and more particularly to a core assembly for a heat exchanger. 
     A heat exchanger is utilized to cool or heat a fluid medium by flowing two fluid mediums adjacent to each other through a core assembly. The heat exchanger may be employed in various applications and subjected to specific thermal requirements. The dimensions of the components of the heat exchanger, and more particularly the core assembly play a significant role in meeting the operating requirements and in withstanding the thermal requirements noted above. This often means that the core designed for each specific application. Thus restricting the use of the overall heat exchanger to other applications outside of the design range of the core. A more cost efficient and flexible heat exchanger design is greatly desired. 
     SUMMARY 
     According to one embodiment, a heat exchanger is provided. The heat exchanger having: a housing having a first housing inlet, a second housing inlet, a first housing outlet, and a second housing outlet; and a core assembly disposed within the housing and removably connected to the housing, the core assembly comprises: a first fluid passage fluidly connecting the first housing inlet to the first housing outlet and a second fluid passage fluidly connecting the second housing inlet to the second housing outlet. The first fluid passage is thermally connected to the second fluid passage. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include that the housing further includes a top portion having a mounting flange and an opposing bottom portion; and the core assembly further comprises a top side having a core flange and an opposing bottom side. The core flange mounts onto the opposing mounting flange and the bottom side of the core assembly abuts the bottom portion of the housing when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include that the core flange of the core assembly is removably connected to the mounting flange of the housing by a plurality of fasteners. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include a first seal interposed between the bottom side of the core assembly and the bottom portion of the housing, the first seal being configured to seal the fluid connection between the second housing inlet and the second fluid passage and seal the fluid connection between the second housing outlet and the second fluid passage when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include that the core assembly further comprises a knife edge located on the bottom part of the core assembly and configured to compress the first seal when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include a second seal interposed between the core flange of the core assembly and the mounting flange of the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include corner seals at each corner of the core assembly, the corner seals being configured to seal the interface between an inner surface of the housing and an outer surface of the core assembly when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include that the housing further includes a tapered pin; and the core assembly further includes rings configured to fit around the tapered pin when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include that the core assembly is cuboid in shape having a top side, an opposing bottom side, and four sides interposed between the top side and the bottom side, the bottom side includes a second core inlet aligned with the second inlet and a second core outlet aligned with the second housing outlet when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the heat exchanger may include that the second fluid passage of the core assembly includes at least two passes across the flow direction of the first fluid passage. 
     According to another embodiment, a method of assembling a heat exchanger is provided. The method including: forming a housing having a first housing inlet, a second housing inlet, a first housing outlet, and a second housing outlet; positioning a core assembly within the housing, the core assembly includes: a first fluid passage fluidly connecting the first housing inlet to the first housing outlet and a second fluid passage fluidly connecting the second housing inlet to the second housing outlet, the first fluid passage is thermally connected to the second fluid passage; and removably connecting the core assembly to the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include forming a mounting flange on a top portion of the housing, the top portion being opposite a bottom portion. The core assembly further includes a top side having a core flange and an opposing bottom side, the core flange mounts onto the opposing mounting flange and the bottom side of the core assembly abuts the bottom portion of the housing when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the core flange of the core assembly is removably connected to the mounting flange of the housing by a plurality of fasteners. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include positioning a first seal interposed between the bottom side of the core assembly and the bottom portion of the housing, the first seal being configured to seal the fluid connection between the second housing inlet and the second fluid passage and seal the fluid connection between the second housing outlet and the second fluid passage when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the core assembly further includes a knife edge located on the bottom part of the core assembly and configured to compress the first seal when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include positioning a second seal interposed between the core flange of the core assembly and the mounting flange of the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include positioning corner seals at each corner of the core assembly, the corner seals being configured to seal the interface between an inner surface of the housing and an outer surface of the core assembly when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the housing further comprises a tapered pin; and the core assembly further comprises rings configured to fit around the tapered pin when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the core assembly is cuboid in shape having a top side, an opposing bottom side, and four sides interposed between the top side and the bottom side, the bottom side includes a second core inlet aligned with the second inlet and a second core outlet aligned with the second housing outlet when the core assembly is disposed within the housing. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the second fluid passage of the core assembly includes at least two passes across the flow direction of the first fluid passage. 
     Technical effects of embodiments of the present disclosure include a heat exchanger having a removable core assembly. 
     The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, that the following description and drawings are intended to be illustrative and explanatory in nature and non-limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter is particularly pointed out and distinctly claimed at the conclusion of the specification. The foregoing and other features, and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is an isometric view of a heat exchanger, according to an embodiment of the present disclosure; 
         FIG. 2  is an exploded view of the heat exchanger of  FIG. 1 , according to an embodiment of the present disclosure; 
         FIG. 3  is a cross-sectional side view of the heat exchanger of  FIG. 1  taken along line  3 - 3 , according to an embodiment of the present disclosure; 
         FIG. 4  is an enlarged cross-sectional side view of the heat exchanger of  FIG. 3 , according to an embodiment of the present disclosure; 
         FIG. 5  is a cross-sectional top view of the heat exchanger of  FIG. 1  taken along line  5 - 5 , according to an embodiment of the present disclosure; 
         FIG. 6  is an enlarged cross-sectional top view of the heat exchanger of  FIG. 5 , according to an embodiment of the present disclosure; 
         FIG. 7  is a cross-sectional top view of the heat exchanger of  FIG. 1  taken along line  7 - 7 , according to an embodiment of the present disclosure; and 
         FIG. 8  is a flow process illustrating a method of manufacturing the heat exchanger of  FIGS. 1-7 , according to an embodiment of the present disclosure. 
     
    
    
     The detailed description explains embodiments of the present disclosure, together with advantages and features, by way of example with reference to the drawings. 
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-7 , a heat exchanger  100  is illustrated. The heat exchanger  100  may be used in conjunction with an assembly or system of a vehicle, such as an aircraft, however, it is contemplated that other vehicles may benefit from the embodiments described herein. In one embodiment, the heat exchanger  100  is part of an air conditioning system or refrigeration system of an aircraft. 
     The heat exchanger  100  includes a core assembly  150  disposed within the housing  120  and removably connected to the housing  120 . The core assembly  150  may be removably connected to the housing  120  by a plurality of fasteners  190 , as seen in  FIG. 1 . The housing  120  includes a top portion  120   a , a bottom portion  120   b , an inner surface  120   c , and an outer surface  120   d . The housing  120  may also include a mounting point  104  to mount the housing  120  to a structural support, such as, for example, a structural frame of an aircraft. The housing  120  also includes a first housing inlet  122  for a first fluid  10 , such as, for example, cold air from an air cycle machine (ACM) turbine (not shown). A mixer  110  may be located at the first housing inlet  122 , as seen in  FIGS. 1-3, 5, and 7 . The housing  120  also includes a first housing outlet  128  for the first fluid  10  to exit the heat exchanger  100 . The first housing outlet  128  may lead the first fluid  10  overboard or outside a vehicle. A first fluid passage  153 , located in the core assembly  150 , fluidly connects the first housing inlet  122  to the first housing outlet  128 . Thus, the first fluid  10  flows F 1  from an ACM turbine through the mixer  110  and into the core assembly  150  through the first housing inlet  122 . Once the first fluid  10  has flowed F 6  through the first fluid passage  153  of the core assembly  150 , the first fluid  10  flows F 5  out of the heat exchanger  100  through the first housing outlet  128 . 
     Additionally, the housing includes a second housing inlet  124  for a second fluid  20 , such as, for example, warm air from an ACM compressor (not shown). The housing  120  also includes a second housing outlet  126  for the second fluid  20  to exit the heat exchanger  100 . The second housing outlet  126  may lead the second fluid  20  to a cabin of a vehicle or aircraft. A second fluid passage  163 , located in the core assembly  150 , fluidly connects the second housing inlet  124  to the second housing outlet  126 . Thus, the second fluid  20  flows F 2  from an ACM compressor into the core assembly  150  through the second housing inlet  124 . Once the second fluid  20  has flowed F 3  through the second fluid passage  163  of the core assembly  150 , the second fluid  20  flows F 4  out of the heat exchanger  100  through the second housing outlet  126 . 
     The core assembly  150  includes a top side  150   a , a bottom side  150   b , an inner surface  150   c , and an outer surface  150   d . The bottom side  150   b  of the core assembly  150  abuts the bottom portion  120   b  of the housing  120  when the core assembly  150  is disposed within the housing  120 . The core assembly  150  includes core  160  having a first fluid passage  153  having a first core inlet  154  and a first core outlet  156 . As may be appreciated by one of skill in the art, the core  160  may include various designs for the exchange of heat between the first fluid passage  153  and the second fluid passage including various core types and header types. The core assembly also includes a second fluid passage  163  having a second core inlet  164  and a second core outlet  166 . The first fluid passage  153  is thermally connected to the second fluid passage  163 . When the core assembly  150  is disposed within the housing  120  the first core inlet  154  is aligned with the first housing inlet  122 , the second core inlet  164  is aligned with the second housing inlet  124 , the first core outlet  156  is aligned with the first housing outlet  128 , and the second core outlet  166  is aligned with the second housing outlet  126  as seen in  FIG. 3 . A first seal  172  is interposed between the bottom side  150   b  of the core assembly  150  and the bottom portion  120   b  of the housing  120 , as seen in  FIGS. 4 and 7 . The first seal  172  is configured to seal the fluid connections between the second housing inlet  124  and the second fluid passage  163  and the fluid connection between the second core outlet  166  and the second fluid passage  163 . In other words, the first seal  172  is configured to seal the fluid connections between the second housing inlet  124  and the second core inlet  164  and also seal the fluid connection between the second core outlet  166  and the second housing outlet  126 . In an embodiment, the first seal  172  may be a compression seal and/or hollow tube seal. 
     Proximate the outer surface  150   d  of the core assembly  150  portions, of the first fluid passage  153  and the second fluid passage  163  that compose the core  160  may form an outer edge  155  of the core  160 . The outer edge  155  may provide additional structural support to the core assembly  150 . The outer edge  155  may include a knife edge  155   a  proximate the bottom  150   b  of the core assembly  150 . The knife edge  155   a  is configured to compress the first seal  172 . The outer edge  155 , may also include rings  155   b  configured to fit around a tapered pin  130 , as seen in  FIG. 4 . In the illustrated embodiment, the heat exchanger  100  includes four tapered pins  130  affixed to the bottom portion  120   b  of the housing  120 . The tapered pins  130  are configured to help align the core assembly  150  within the housing  120 . As the core assembly  150  is inserted into the housing  120  the rings  155   b  slide in around the tapered pins  130 . In operation, heat may cause the core assembly  150  to expand and contract and as this occurs the rings  155   b  are free to slide up D 1  and down D 2  on the pins. 
     In the illustrated embodiment the core  160  has a two pass design where the second fluid passage  163  of the core assembly  150  includes at least two passes across the flow direction F 6  of the first fluid passage  153 . The two pass design allows the second fluid  20  to flow F 3  through the core  160  twice within the second fluid passage  163  before exiting the core  160 . The second fluid passage  163  utilizes a domed header  157 , located at the top side  150   a , to redirect the flow F 3  one-hundred and eighty degrees from the second core inlet  164  to the second fluid exit  166 , thus allowing the second fluid  20  to pass through the core  160  twice. The first fluid  10  flows F 6  through the first fluid passage  153 , which is arranged perpendicular to the second fluid passage  163 . As may be appreciated by one of skill in the art there may be multiple first fluid passages  153  and multiple second fluid passages  163 ; however a single first fluid passage  153  and a single second fluid passage  163  are shown for simplicity. Further, as may be appreciated by one of skill in the art the core  160  may include a variety of different fin designs and patterns for the first fluid passage  153  and the second fluid passage  160  to achieve the desired thermal transfer between the fluid passages  153 ,  163 . 
     As mentioned above, the core assembly  150  is removably connected to the housing  120 , which means that the core assembly  150  may be inserted into the housing  120  and secured to the housing  120 ; and then the core assembly  150  may be unsecured from the housing  120  and removed from the housing  120 . As also mentioned above, the core assembly  150  is secured to the housing  120  by a plurality of fasteners  190 . As seen in  FIG. 2 , a core flange  159  on the core assembly  150  mounts onto an opposing mounting flange  129  on the housing  120  and the fasteners  190  secure the core flange  159  to the mounting flange  129 . The mounting flange  129  is located proximate the top portion  120   a  of the housing  120 . In an embodiment, the fasteners may be a bolt that screws into pre-drilled holes in the mounting flange  129 . A second seal  174  is interposed between the core flange  159  and the mounting flange  129 , as seen in  FIG. 3 . The second seal  174  is configured to act as a gasket and seal the interface between the core flange  174  and the mounting flange  129 . The second seal  174  may be composed of an elastomeric material. 
     The core assembly  150  also includes a plurality of corner seals  180  located at each corner  150   e  of the core assembly  150 , as seen in  FIG. 5 , to provide air sealing at each corner  150   e  when the core assembly  150  disposed within the housing  120 . The corner seals  180  may also help guide the core assembly  150  during installation and removal of the core assembly  150  from the housing  120 . The corner seals  180  are configured to seal the interface between an inner surface  120   c  of the housing  120  and an outer surface  120   d  of the core assembly  150  when the core assembly  150  is disposed within the housing  120 . The corner seals  180  may be composed of an elastomeric or similar material. The corner seals  180  may have a corner fitting  186  help fit with each corner  150   e  of the core assembly  150 . The corner seals  180  may be fixedly connected to the outer surface  150   d  of the core assembly  150  at each corner  150   e . The corner seals  180  may be fixedly connected to the outer surface  150   d  by an adhesive (not shown) applied between the corner fitting  186  and the corner  150 . The corner seal  180  may also include teeth  182 , as seen in  FIG. 6 , to aid in sealing between the corner seal  180  and the inner surface  120   c  of the housing  120 . The teeth  182  may also slide relative to the inner surface  120   c  of the core assembly  150  is inserted into the housing  120  and removed from the housing  120 . Additionally, the corner seal  180  may include a center core  188 . Advantageously, the center core  188  may aid in compression and also provide weight savings. In the illustrated embodiment, the core assembly  150  is cuboid in shape having six sides including the top side  150   a  and an opposing bottom side  150   b  having the second core inlet  164  and the second core outlet  166 . The four sides interposed between the top side  150   a  and the bottom side  150   b  includes two opposing side walls  151 , the first core inlet  154 , and the first core outlet  156 . The corner seals  180  are each located at the four corners  150   e  of the four sides interposed between the topside  150   a  and the bottom side  150   b.    
     Referring now to  FIG. 8 , while referencing components of the heat exchanger  100  of  FIGS. 1-7 ,  FIG. 8  shows a flow process illustrating a method  800  of assembling the heat exchanger  100  of  FIGS. 1-7 . At block  804 , the housing  120  is formed. The housing  120  may be formed by various manufacturing methods including but not limited to molds, machining, additive manufacturing, and/or any other method known to one of skill in the art. As discussed above, the housing has a first housing inlet  122 , a second housing inlet  124 , a first housing outlet  128 , and a second housing outlet  126 . At block  806 , the core assembly  150  is positioned within the housing. As mentioned above, the core assembly  150  comprises a first fluid passage  153  fluidly connecting the first housing inlet  122  to the first housing outlet  128  and a second fluid passage  163  fluidly connecting the second housing inlet  124  to the second housing outlet  126 . The first fluid passage  153  is thermally connected to the second fluid passage  163 . 
     At block  808 , the core assembly  150  is removably connected to the housing  120 . As discussed above, fasteners  190  may be used to removably connect the core assembly  150  to the housing  120 . At block  810 , the mounting flange  129  is formed on the top portion  120   a  of the housing  120 . The top portion  120   a  is opposite the bottom portion  120   b . As mentioned above, the core assembly  150  further comprises a top side  150   a  having a core flange  159  and an opposing bottom side  150   b . The core flange  159  mounts onto the opposing mounting flange  129  and the bottom side  150   b  of the core assembly  150  abuts the bottom portion  120   b  of the housing  120  when the core assembly  150  is disposed within the housing  120 . 
     At block  812 , the first seal  172  is positioned interposed between the bottom side  150   b  of the core assembly  150  and the bottom portion  120   b  of the housing  120 . The first seal  172  being configured to seal the fluid connection between the second housing inlet  124  and the second fluid passage  163  and seal the fluid connection between the second housing outlet  126  and the second fluid passage  163  when the core assembly  150  is disposed within the housing  120 . At block  814 , the second seal  174  is positioned interposed between the flange  159  of the core assembly  150  and the mounting flange  129  of the housing  120 . 
     While the above description has described the flow process of  FIG. 8  in a particular order, it should be appreciated that unless otherwise specifically required in the attached claims that the ordering of the steps may be varied. 
     While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions, combinations, sub-combinations, or equivalent arrangements not heretofore described, but which are commensurate with the scope of the present disclosure. Additionally, while various embodiments of the present disclosure have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments. Accordingly, the present disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.