Flat tube heat exchanger
A flat tube heat exchanger is provided including a first flat side and a second flat side opposite the first flat side joined together by two opposing sides. At least one internal partition defines a flow duct within the interior of the heat exchanger. A bend is provided in the plane substantially defined by the first flat side.
The present invention relates generally to the field of heat exchangers. More specifically, the present invention relates to a flat tube heat exchanger having a bend in the plane of a flat side of the tube.
BACKGROUND OF THE INVENTIONHeat exchanger coils have been used for many years in various refrigeration systems. Heat exchanger coils have traditionally been formed with round tubing. The coils can be configured in variety of shapes to suit the needs of a particular application. One example of the use of such heat exchanger coils is in refrigerators or reach-in coolers for presenting food and/or beverages items to customers while maintaining the food and/or beverage items in a refrigerated environment. Such reach-in coolers can include a shelf on which food items are stored. In one conventional practice, a heat exchanger coil of round tubing is connected to the bottom of the shelf/plate on which the food/beverage items are stored. A suitable refrigerant is passed through the heat exchanger to act as a heat exchange medium. The refrigerant in the heat exchange coil absorbs heat from the shelf and causes the refrigerant to evaporate as it passes through the heat exchanger. As a result, the temperature of the shelf is reduced, thereby keeping the items placed on the top surface thereof at a reduced temperature.
Heat exchanger coils having a flat tube configuration have also been formed for particular applications. Flat tube heat exchanger coils have been formed with two opposing flat sides and two interconnecting sides. In order to form a heat exchanger structure, a bend was placed in a plane defined by the interconnecting sides. It was understood that the bend would have to be formed in this manner because the material forming the tube would fracture if the bend was placed in a plane formed by the opposing flat sides.
Improvements have been sought in many heat exchangers which decrease the amount of necessary refrigerant materials. Also, improvements have been sought which would increase the heat transfer surface area of the heat exchanger coil in order to increase the efficiency of the system. As a result, there is a need for an improved heat exchanger tubing that assists in increasing the efficiency of the system while not adding undesirable features such as air restriction and excess material.
SUMMARY OF THE INVENTIONThe present invention is directed to a flat tube heat exchanger tube that has improved efficiencies over heat exchanger tubes of the past. The present invention provides a flat tube heat exchanger that increases the heat transfer surface area while minimizing the internal cross-section of the tube, thereby minimizing the use of refrigerant within the heat exchanger tube. The flat tube heat exchanger of the present invention forms a novel shape offering improved air flow capabilities over the heat exchanger and a larger primary heat transfer surface for improved efficiency. The present invention also provides for an increased usable primary surface area, reduced secondary surface requirement, reduced air restriction, fewer braze joints, and reduced thermal resistance.
The present invention provides in one aspect, a flat tube heat exchanger including a first flat side and a second flat side opposite the first flat side joined together by two opposing sides. At least one internal partition defines a flow duct within the interior of the heat exchanger. A bend is provided in the plane substantially defined by the first flat side.
The present invention provides, in another aspect, a flat tube heat exchanger formed from a single one piece element having a first flat side and a second flat side opposite the first flat side and joined together by two opposing sides. At least one internal partition is provided to define a flow duct. The first flat side and second flat side define a width axis. The two opposing sides define a height axis. The flat tube heat exchanger has a U-shaped bend extending substantially around the height axis.
The present invention, together with attendant objects and advantages, will be best understood with reference to the detailed description below in connection with the attached drawings.
The present invention is directed to a flat tube heat exchanger useful in many different environments where heat transfer is necessary, such as refrigeration systems, radiators, oil coolers, air coolers, condensers, evaporators and heat sinks. For example, while the drawing of the embodiment of the present invention illustrates the use of an embodiment of the flat tube heat exchanger in a refrigeration environment, the present invention can be used in other types of heat transfer, such as air to liquid, air to air, liquid to liquid, or liquid to air. The flat tube heat exchanger of the present invention can take a wide variety of shapes and sizes beyond the specific embodiment illustrated in the present invention. Further, the heat transfer may take place in either direction depending upon the application.
A first embodiment of the flat tube heat exchanger 10 of the present invention is illustrated in
The plate 12 includes a top surface (not shown), a bottom surface 14, and sides 16. The flat tube heat exchanger tube 10 is attached to the bottom of the plate 12 using conventional attachment elements such as a very high bonding double sided tape, an adhesive or other known conventional fastening mechanism.
The flat tube heat exchanger 10 is illustrated in a serpentine embodiment as best illustrated in
A series of internal partitions 40 are provided between the first flat side 26 and the second flat side 28. The flow ducts 42 form a passageway for refrigerant or other heat transfer medium through the flat tube heat exchanger 10. The present embodiment illustrates the use of eleven flow ducts 42. However, it should be recognized that the number of flow ducts may be selected to suit the needs of a particular application. The internal partitions 40 provide additional strength to the flat tube heat exchanger 10 and assist in the heat transfer function.
With reference to
The flat tube heat exchanger 10 can be formed having a width in the range of 0.375 to 3 inches and with a tube thickness in the range of 0.062 to 0.5 inches. The wall thickness may depend on the material used to form the tube and the particular application. The flat tube heat exchanger 10 may be formed in a number of various lengths and widths and out of a number of various known materials, e.g., aluminum, as necessary to suit needs of the particular application.
The flat tube heat exchanger 10 is formed using a conventional serpentine type bender. The machine is equipped with tooling to support and minimize deformation of the manufactured tube bends, in order to retain it in a flat configuration. In particular, the flat tube heat exchanger is formed by crushing the tube into a radius formed block to maintain a consistent flow of material throughout the bend. Crushing compression is applied by a follow block formed to hold and shape the material flat and parallel to the heat exchanger. The tube is fully enclosed by the inside radius block and the follow-up block to maintain the overall tube dimensions and shape. The flat tube heat exchanger 10 is formed by bending the tube while simultaneously supporting the sides and radii.
The embodiments described above and shown herein are illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description and attached drawings. The invention may be embodied in other specific forms without departing from the spirit of the invention. For example, the overall configuration of the flat tube heat exchanger of the present invention may be designed and configured in a manner other than as specifically illustrated in the figures. In addition, the present invention may be used with or without fins. Accordingly, these and any other changes which come within the scope of the claims are intended to be embraced herein.
Claims
1. A one piece flat tube heat exchanger comprising:
- a first flat side and a second flat side opposite the first flat side, the first flat side and the second flat side joined together by two opposing sides, at least one internal partition to define a flow duct interconnecting the first flat side and the second flat side, the flat tube heat exchanger having a bend in a plane substantially defined by the first flat side whereby a flat tube heat exchanger is formed with the bend portion formed substantially coplanar with the first flat side.
2. The flat tube heat exchanger of claim 1 wherein the two opposing sides are rounded.
3. The flat tube heat exchanger of claim 1 wherein the flat tube heat exchanger has a serpentine pattern.
4. The flat tube heat exchanger of claim 1 wherein the bend forms a U-shape.
5. The flat tube heat exchanger of claim 1 wherein the flat tube heat exchanger has a helical pattern.
6. The flat tube heat exchanger of claim 1 wherein the flat tube heat exchanger has a layered pattern.
7. The flat tube heat exchanger of claim 6 wherein the flat tube heat exchanger has a layered pattern that is generally symmetric.
8. The flat tube heat exchanger of claim 1 wherein the flat tube heat exchanger further comprises another bend in a plane defined by at least one of the two opposing sides.
9. The flat tube heat exchanger of claim 8 wherein the flat tube heat exchanger further comprises a plurality of fins.
10. A flat tube heat exchanger, comprising:
- a single one piece element including a first flat side and a second opposed flat side joined together by two opposing sides, at least one internal partition to define a flow duct, the flat tube heat exchanger having a width axis defined by the first flat side and the second flat side and a height axis defined by the two opposing sides, the flat tube heat exchanger having a U-shaped bend extending substantially around the height axis.
11. The flat tube heat exchanger of claim 10 wherein the two opposing sides are rounded.
12. The flat tube heat exchanger of claim 10 wherein the flat tube heat exchanger has a serpentine pattern.
13. The flat tube heat exchanger of claim 10 wherein the flat tube heat exchanger has a helical pattern.
14. The flat tube heat exchanger of claim 10 wherein the flat tube heat exchanger has a layered pattern.
15. The flat tube heat exchanger of claim 14 wherein the flat tube heat exchanger has a layered pattern that is generally symmetric.
16. The flat tube heat exchanger of claim 10 wherein the flat tube heat exchanger further comprises another bend extending around the width axis.
17. The flat tube heat exchanger of claim 16 wherein the flat tube heat exchanger further comprises a plurality of fins.
18. The flat tube heat exchanger of claim 10 wherein the flat tube heat exchanger is formed.
19. A refrigerator, comprising:
- a flat tube heat exchanger tube formed as a one piece element including a first flat side and a second opposed flat side joined together by two opposing sides, at least one internal partition to define a flow duct, the flat tube heat exchanger having a U-shaped bend in the plane substantially defined by the first flat side.
20. The refrigerator of claim 19 wherein the bend forms a U-shape.
Type: Application
Filed: Jun 7, 2007
Publication Date: Dec 11, 2008
Inventors: Joseph Durdel (Sigel, IL), Kevin Gurley (Effingham, IL), James Siemer (Effingham, IL), Michael Warkins (Vernon Hills, IL)
Application Number: 11/810,944
International Classification: F28D 1/00 (20060101);