HEAT EXCHANGER
A heat exchanger (28 includes a first manifold (34), a second manifold (36) and a plurality of parallel heat transfer tubes (38). The first manifold (34) includes one or more manifold sections (58, 60, 63). A first one of the manifold sections (58) is connected to an inlet (64). The heat transfer tubes (38) extend between and fluidly connect the first and the second manifolds (34, 36). At least some of the heat transfer tubes (38) are disposed with the first manifold section (58).
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Applicant hereby claims priority benefits under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/318,592 filed Mar. 29, 2010, the disclosure of which is herein incorporated by reference.
BACKGROUND OF THE INVENTION1. Technical Field
The present invention relates generally to heat exchangers, and particularly to heat exchangers having structures operable to decrease thermal mechanical fatigue therein.
2. Background Information
A typical two-pass microchannel condenser includes a plurality of parallel microchannel tubes that extends between a first manifold and a second manifold. The first manifold includes an inlet section connected to a refrigerant inlet, and an outlet section connected to a refrigerant outlet. The refrigerant inlet is disposed at a top end of the inlet section. During operation, refrigerant is directed into the inlet section of the first manifold through the refrigerant inlet. The inlet section of the first manifold directs the refrigerant through a first set of the microchannel tubes and into the second manifold. The second manifold then redirects the refrigerant through a second set of the microchannel tubes to the outlet section of the first manifold. As ambient air is forced around the microchannel tubes, thermal energy is transferred from the refrigerant in the tubes into the ambient air, thereby cooling the refrigerant.
Depending upon size and geometry of the condenser and the ambient conditions, the temperature of the refrigerant passing through the condenser can be reduced more than 100-150 degrees Fahrenheit (° F.). A temperature drop of this magnitude can subject elements of the condenser (e.g., a section of the first manifold between the inlet section and the outlet section) to a relatively large temperature gradient. Additionally, as the refrigerant is initially distributed from the refrigerant inlet into the first set of the microchannel tubes, the portion of the tubes proximate the top corner of the condenser can also be subjected to a substantial temperature gradient. Substantial temperature gradients within elements of the condenser can result in relatively high thermally induced stresses in those elements. The high stresses can, in turn, cause mechanical fatigue and failure in the elements.
SUMMARY OF THE DISCLOSUREAccording to a first aspect of the invention, a heat exchanger is provided that includes a first manifold, a second manifold and a plurality of parallel heat transfer tubes. The first manifold includes an inlet manifold section fluidly connected to an inlet. The inlet manifold section extends along a centerline between a first end and a second end. The heat transfer tubes extend between and fluidly connect the first and the second manifolds. An integer “N” number of the heat transfer tubes are disposed along the centerline between the inlet and the first end of the inlet manifold section. An integer “M” number of the heat transfer tubes are disposed along the centerline between the inlet and the second end of the inlet manifold section. “N” is approximately equal to “M”.
According to a second aspect of the invention, a heat exchanger is provided that includes a first manifold, a second manifold and a plurality of parallel heat transfer tubes. The first manifold includes a plurality of manifold sections. A first one of the manifold sections is disposed adjacent to, and configured discrete from, a second one of the manifold sections. The heat transfer tubes extend between and fluidly connect the first and the second manifolds. At least some of the heat transfer tubes are disposed with the first manifold section. At least some of the heat transfer tubes are disposed with the second manifold section.
According to a third aspect of the invention, a heat exchanger is provided that includes a first manifold, a second manifold and a plurality of parallel heat transfer tubes. The first manifold includes an inlet manifold section connected to an inlet. The heat transfer tubes extend between and fluidly connect the first and the second manifolds. A region of the heat exchanger, between the first and the second manifolds, is adapted having a reduced heat transfer coefficient. This reduced heat transfer coefficient region is disposed proximate the inlet.
The foregoing features and advantages and the operation of the invention will become more apparent in light of the following description and the accompanying drawings.
Referring to
Referring to
The first manifold 34 extends along a first centerline 52 (e.g., parallel to the y-axis) between two ends 54 and 56. The first manifold 34 includes one or more manifold sections 58, 60, 62 and one or more refrigerant inlet/outlet apertures 64, 66, 68 (hereinafter “I/O apertures”). In the embodiment in
In the embodiment in
The second manifold 36 extends along a second centerline 82 (e.g., parallel to the y-axis) between two ends 84 and 86. The second manifold 36 includes one or more manifold sections 88, 90 and at least one I/0 aperture 92. In the embodiment in
The HT tubes 38 are arranged in parallel rows that extend (e.g., substantially perpendicular to the first and the second centerlines 52 and 82) between the first and the second manifolds 34 and 36. The HT tubes 38 can further be arranged into a plurality of HT tube sets 100, 102, 104. For example, the HT tubes 38 in the heat exchanger 28 in
Referring now to
The cooling fins 40 are arranged into a plurality of rows 110, 112 and 114. Each row of cooling fins 110, 112, 114 is respectively disposed between a pair of adjacent HT tubes 38 within each heat exchanger section 30, 32. In some embodiments, a row of cooling fins can also be disposed between a pair of HT tubes 38 that are each disposed in different heat exchanger sections 30, 32 (not shown). The cooling fin 40 in each row 110, 112, 114 that is disposed closest to the first manifold 34 (i.e., the “first fin”) can be adjacent or in contact with the first manifold (e.g., see
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Referring to the embodiments in
In the specific embodiment in
In the specific embodiment in
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As set forth above in a prior art heat exchanger, refrigerant distributing into a region of the heat exchanger proximate the refrigerant inlet can be repeatedly subjected to relatively large thermal gradients. As a result, that region can be subjected to stress and fatigue resulting from the thermal gradients. To resolve this problem, some embodiments of the present invention locate the condenser inlet 64 intermediately between the “N” and the “M” numbers of HT tubes 38. By so locating the inlet 64 relative to the HT tubes 38, the refrigerant more uniformly distributes within the HT tubes 110, and thereby decreases the potential for a substantial thermal gradient within the region.
Referring to
Referring again to
Depending upon size and geometry of the condenser section 30 and ambient conditions, the refrigerant can be cooled more than, for example, 100-150 degrees Fahrenheit (° F.) as it flows through the first and the second passes of the condenser section 30. As set forth above, such a temperature drop can subject a mid section of a prior art manifold, between an inlet manifold section and an outlet manifold section, to a relatively sharp temperature gradient. Referring to
Referring again to
While various embodiments of the present invention have been disclosed, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. For example, the first and/or the second manifolds 34 and 36 can each include additional manifold sections (e.g., return sections) such that the refrigerant can complete additional passes through one or more of the heat exchanger sections. Accordingly, the present invention is not to be restricted except in light of the attached claims and their equivalents.
Claims
1. A heat exchanger, comprising:
- a first manifold including an inlet manifold section fluidly connected to an inlet, which inlet manifold section extends along a centerline between a first end and a second end;
- a second manifold; and
- a plurality of parallel heat transfer tubes extending between and fluidly connecting the first and the second manifolds, wherein “N” number of the heat transfer tubes are disposed along the centerline between the inlet and the first end of the inlet manifold section, wherein “M” number of the heat transfer tubes are disposed along the centerline between the inlet and the second end of the inlet manifold section, and wherein “N” and “M” are integers and “N” is approximately equal to “M”.
2. The heat exchanger of claim 1, wherein the first manifold further includes a second manifold section that extends along a centerline, and wherein at least some of the heat transfer tubes are disposed along the centerline of the second manifold section.
3. The heat exchanger of claim 2, wherein the inlet manifold section is disposed adjacent to the second manifold section, and wherein the inlet manifold section is discrete from the second manifold section.
4. The heat exchanger of claim 3, wherein the inlet manifold section is spaced a distance away from the second manifold section.
5. The heat exchanger of claim 2, wherein the inlet manifold section and the second manifold section are fluidly separated by a baffle.
6. The heat exchanger of claim 1, wherein a region of the heat exchanger, between the first and the second manifolds, is adapted having a reduced heat transfer coefficient, which reduced heat transfer coefficient region is disposed proximate the inlet.
7. The heat exchanger of claim 6, further comprising a plurality of rows of cooling fins respectively disposed between adjacent rows of the heat transfer tubes, wherein a distance is disposed between the first manifold and a respective cooling fin closest thereto for Q number of rows, wherein the distance is incrementally decreased as the respective rows are disposed farther away from the inlet, and wherein Q is an integer greater than 2.
8. The heat exchanger of claim 7, wherein the cooling fins in adjacent rows are staggered relative to one another.
9. The heat exchanger of claim 6, wherein the reduced heat transfer coefficient region includes an airflow reduction element that is disposed with the heat transfer tubes proximate the inlet.
10. A heat exchanger, comprising:
- a first manifold including a plurality of manifold sections, a first one of the manifold sections being disposed adjacent to, and configured discrete from, a second one of the manifold sections;
- a second manifold; and
- a plurality of parallel heat transfer tubes extending between and fluidly connecting the first and the second manifolds, wherein at least some of the heat transfer tubes are disposed with the first manifold section, and wherein at least some of the heat transfer tubes are disposed with the second manifold section.
11. The heat exchanger of claim 10, wherein the first manifold section is spaced a distance away from the second manifold section.
12. The heat exchanger of claim 10, wherein the first manifold section and the second manifold section are fluidly separated by a baffle.
13. The heat exchanger of claim 10, wherein the first manifold section is connected to an inlet.
14. The heat exchanger of claim 13, wherein the first manifold section extends along a centerline between a first end and a second end, wherein “N” number of the heat transfer tubes are disposed along the centerline between the inlet and the first end of the first manifold section, and wherein “M” number of the heat transfer tubes are disposed along the centerline between the inlet and the second end of the first manifold section, wherein “N” and “M” are integers and “N” is approximately equal to “M”.
15. The heat exchanger of claim 10, wherein a region of the heat exchanger between the first and the second manifolds has a reduced heat transfer coefficient, and which region is disposed proximate the inlet.
16. The heat exchanger of claim 15, further comprising a plurality of rows of cooling fins respectively disposed between adjacent rows of the heat transfer tubes, wherein a distance is disposed between the first manifold and a respective cooling fin closest thereto for “Q” number of rows, wherein this distance is incrementally decreased as the respective rows are disposed farther away from the inlet, and wherein “Q” is an integer greater than 2.
17. The heat exchanger of claim 15, wherein the reduced heat transfer coefficient region includes an airflow reduction element that is disposed with the heat transfer tubes proximate the inlet.
18. A heat exchanger, comprising:
- a first manifold including an inlet manifold section connected to an inlet;
- a second manifold; and
- a plurality of parallel heat transfer tubes extending between and fluidly connecting the first and the second manifolds;
- wherein a region of the heat exchanger, between the first and the second manifolds, is adapted having a reduced heat transfer coefficient, which reduced heat transfer coefficient region is disposed proximate the inlet.
19. The heat exchanger of claim 18, further comprising a plurality of rows of cooling fins respectively disposed between adjacent rows of the heat transfer tubes, wherein a distance is disposed between the first manifold and a respective cooling fin closest thereto for “Q” number of rows, wherein this distance is incrementally decreased as the respective rows are disposed farther away from the inlet, and wherein “Q” is an integer greater than 2.
20. The heat exchanger of claim 18, wherein the reduced heat transfer coefficient region includes an airflow reduction element that is disposed with the heat transfer tubes proximate the inlet.
21. The heat exchanger of claim 18, further comprising a plurality of rows of cooling fins respectively disposed between adjacent rows of the heat transfer tubes, and wherein the reduced heat transfer coefficient region includes a plurality of finless regions disposed between the adjacent rows of the heat transfer tubes proximate the inlet.
Type: Application
Filed: Dec 23, 2010
Publication Date: Jul 11, 2013
Applicant: CARRIER CORPORATION (Farmington, CT)
Inventors: John T. Steele (Marcellus, NY), Eric Johnson (Palmyra, NY), Lester G. Harrington (Lafayette, NY), Christopher G. Repice (Camillus, NY), Jason A. Gough (Marcellus, NY), Scott D. Fulmer (Liverpool, NY)
Application Number: 13/638,864
International Classification: F28F 1/00 (20060101);