Patent Application
20160231067
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.
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.
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.
The present invention will now be described, by way of example with reference to the accompanying drawings, in which:
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.
