Patent Publication Number: US-2016231067-A1

Title: Heat exchanger with clam-shell header

Description:
TECHNICAL FIELD OF INVENTION 
     This disclosure generally relates to a heat exchanger, and more particularly relates to an upper shell and a lower shell of a clam-shell like assembly configured to form a header of the heat exchanger, where the header defines or includes a manifold portion, a lanced portion, and a distribution portion. 
     BACKGROUND OF INVENTION 
     Current construction techniques for heat exchangers such as evaporators and condensers for air-conditioning systems use headers with internal distributors to distribute and collect the refrigerant. Internal distributors help to reduce “dead” or hot spots at the core of the heat exchanger as air is passed across and/or through the heat exchanger. Typically, headers are roll formed and welded aluminum tubes that must pass through several processes to assemble distribution and/or collector tubes within a manifold, and attach end caps. A more cost efficient way to fabricate headers is desired. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment, a heat exchanger is provided. The heat exchanger includes a header and a plurality of tubes. The header is configured to contain refrigerant and provide an inlet for the heat exchanger. The plurality of tubes extends away from and is fluidicly coupled to the header. The header includes an upper shell and a lower shell configured to form the header when attached together. The upper shell and the lower shell cooperate to define a manifold portion fluidicly coupled to the inlet, a lanced portion spaced apart from the manifold portion and fluidicly coupled to the plurality of tubes, and a distribution portion configured fluidicly couple the manifold portion to the lanced portion. 
     In accordance with one embodiment, a header for a heat exchanger is provided. The heat exchanger includes a plurality of tubes extending away from and fluidicly coupled to the header. The header is configured to contain refrigerant and provide an inlet for the heat exchanger. The header includes an upper shell and a lower shell configured to form the header when attached together. The upper shell and the lower shell cooperate to define a manifold portion fluidicly coupled to the inlet, a lanced portion spaced apart from the manifold portion and fluidicly coupled to the plurality of tubes, and a distribution portion configured fluidicly couple the manifold portion to the lanced portion. 
     Further features and advantages will appear more clearly on a reading of the following detailed description of the preferred embodiment, which is given by way of non-limiting example only and with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention will now be described, by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  is an isometric view of a heat exchanger in accordance with one embodiment; and 
         FIGS. 2A and 2B  are exploded views of the heat exchanger of  FIG. 1  in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1, 2A, and 2B  illustrate a non-limiting example of a heat exchanger  10 , that includes a header  12  configured to contain refrigerant and provide an inlet  16  for the heat exchanger. The heat exchanger  10  also includes a plurality of tubes  14  extending away from and fluidicly coupled to the header  12 . Those in the art will recognize that the heat exchanger  10  described herein is comparable to an evaporator used in an air-conditioning system. However, it is contemplated that the teachings presented herein are applicable to a wide variety of heat exchangers. 
     The header  12  is generally formed of an assembly of part that may be characterized as a clam-shell type assembly. The header  12  includes an upper shell  20  and a lower shell  22  configured to form the header  12  when those and other optional parts are attached together. The upper shell  20  and the lower shell  22  are preferably formed from aluminum sheet stock using one or more stamping operations that are known by those in the art. The upper shell  20  and the lower shell  22  cooperate with each other to define a manifold portion  24  fluidicly coupled to the inlet  16 , a lanced portion  28  spaced apart from the manifold portion  24  and fluidicly coupled to the plurality of tubes  14 , and a distribution portion  26  configured fluidicly couple the manifold portion  24  to the lanced portion  28 . 
     In general, the manifold portion  24  serves as a reservoir where refrigerant or other suitable fluid can collect prior to being expelled from the inlet  16  or after being received via the inlet  16 . If the heat exchanger  10  is being used as an evaporator, the dimensions of the manifold portion  24  are selected to minimize manifold material usage while minimizing refrigerant pressure drop and maximizing cooling performance. 
     The lanced portion  28  is configured to define a plurality of cavities  30 , wherein each of the cavities  30  is fluidicly coupled to an adjacent cavity only via the manifold portion  24 . As used herein, the phrase ‘only via the manifold portion’ means that there is no direct fluidic communication between each of the cavities  30 , and that any local fluidic communication is by way of the manifold portion  24  via distribution passageways  32  of the distribution portion  26 . It is appreciated that there may be fluidic communication between the ends of the tubes  14  opposite those ends coupled to the header  12 , but the phrase ‘only via the manifold portion’ is not applicable or relevant to that fluidic communication because it is not local to the header  12 . 
     The distribution portion  26  defines the plurality of distribution passageways  32  that fluidicly couple each of the cavities  30  to the manifold portion  24 . The sizing of the distribution passageways  32  is selected to provide a degree of restriction so the flow of refrigerant from the manifold portion into each of the cavities  30  is more uniform than would be the case if there was no restriction. However, the restriction should not be too great as to cause a decrease in overall performance of the heat exchanger  10 . 
     In the non-limiting example presented herein, each of the cavities  30  includes a slot  34  that is lanced or otherwise formed through the material that makes up the lower shell  22 . The slot  34  is configured to receive one of the plurality of tubes  14 , and form a fluidic seal with tube when the parts of the heat exchanger are bonded together by, for example, brazing. Accordingly, the ends of the tubes are fluidicly isolated from each other by boundaries of the cavities such that each tube (i.e. the ends of the tubes attached to the header  12 ) is fluidicly coupled to an adjacent tube only via the manifold portion  24 . 
     The upper shell  20  may be configured to define an upper flange  36  and the lower shell may be configured to define a lower flange  38  that are suitable for brazing together to form or assembly the header  12 . Alternatively, the flanges may be configured so the upper shell  20  and the lower shell  22  can be crimped together and optionally sealed using a brazing or soldering process. 
     If the heat exchanger  10  is a dual-pass or multi-pass type heat exchanger, the header  12  may include a separator  40  located in the manifold portion  24  to segregate the manifold into a first region  42  and a second region  44 . Accordingly, the header may include an outlet (not shown) proximate to the second region  44  similar to the way that the inlet  16  is proximate to the first region  42 . 
     Accordingly, a heat exchanger  10 , and in particular a header  12  for the heat exchanger  10 , is provided. The clam-shell like configuration of the upper shell  20  and the lower shell  22  provide for a more economical means to fabricate a header when compared to more traditional configurations that have a tubular manifold with distribution tubes located within the manifold, and slots formed in the wall of the manifold for receiving tubes. Having the manifold portion  24  spaced apart from the lanced portion  28  provides a convenient means to provide the distribution passageways  32  of the distribution portion  26  for better distribution of refrigerant to the tubes  14 . The clam-shell configuration allows for the header  12  to be assembled using two stamped parts (the upper shell  20  and the lower shell  22 ) instead of the traditional way that uses four parts including a manifold tube, a distribution tube within the manifold tube, and two end-caps to seal the ends of the manifold tube. 
     While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.