TUBE END ADAPTER

Abstract

A tube end adapter for a fluid, including a first end, a primary second end and a fluid channel extending therebetween along an extension axis so that the fluid can flow between the first end and the primary second end. The first end has a first opening and a non-circular shape cross-section and is adapted to receive a flat tube of a corresponding cross-section shape, with the primary second end having a primary second opening and a rounded shape cross-section.

Description

TECHNICAL FIELD

The object of the invention is a tube end adapter for a heat exchanger fluid, in particular for a heat exchanger with tubes attached to a header.

BACKGROUND OF THE INVENTION

Heat exchangers can include tubes for a heat exchange fluid. The tubes can be attached to a header, which collects the fluid and allows it to travel further within the fluid loop. In some cases, the connection between the tubes and other elements of the heat exchanger, e.g. the header, can be imperfect. For instance, if the tubes are attached to other components by brazing, the connection at the joint can be faulty and lead to leaking of the fluid. Consequently, the whole heat exchanger needs to be discarded. Repairing and reusing of leaking heat exchangers with inferior brazing joint quality is difficult to achieve.

SUMMARY OF THE INVENTION

An object of the invention is a tube end adapter for a fluid, comprising a first end, a primary second end and a fluid channel extending therebetween along an extension axis so that the fluid can flow between the first end and the primary second end, the first end having a first opening and a non-circular shape cross-section and being adapted to receive a flat tube of a corresponding cross-section shape, with the primary second end having a primary second opening and a rounded shape cross-section.

In one embodiment, the first end extends from the first opening towards the primary second opening, with the tube end adapter maintaining the non-circular shape cross-section throughout the first end.

In one embodiment, the primary second end extends from the primary second opening towards the first opening, with the tube end adapter maintaining the rounded shape cross-section throughout the primary second end.

In one embodiment, the primary second end has a circular cross-section.

In one embodiment, the non-circular shape cross-section of the first end has two oppositely arranged short sides and two oppositely arranged long sides, wherein the primary second opening of the primary second end is shifted towards one of the short sides of the first end in a direction perpendicular to the extension axis.

In one embodiment, the fluid channel includes an intermediate section configured to transition the tube end adapter between the non-circular shape cross-section of the first end and the rounded shape cross-section of the primary second end.

In one embodiment, the primary second end includes an annular snap joint.

In one embodiment, the primary second end is upset.

In one embodiment, the tube end adapter is made of metal.

In one embodiment, the tube end adapter is made of plastic.

In one embodiment, the tube end adapter is made of elastic material.

In one embodiment, the tube end adapter further comprises a secondary second end having a secondary second opening with a rounded shape cross-section, the tube end adapter extending additionally between the first end and the secondary second end to enable fluid flow therebetween.

In one embodiment, the tube end adapter further comprises an intermediate section configured to transition the tube end adapter between the non-circular shape cross-section of the first end and the rounded shape cross-sections of the primary second end and the secondary second end.

Another object of the invention is a heat exchanger, comprising: a plurality of flat tubes for a fluid; a plurality of tube end adapters for a fluid, each including a first end, a primary second end and a fluid channel extending therebetween so that the fluid can flow between the first end and the primary second end, the first end having a first opening and a non-circular shape cross-section and being adapted to receive a flat tube of a corresponding cross-section shape, with the primary second end having a primary second opening and a rounded shape cross-section; a tube header with a plurality of header openings of rounded shape corresponding to the rounded shape cross-sections of the primary second ends of the plurality of tube end adapters; wherein each of the plurality of flat tubes is inserted into the first end of one of the plurality of the tube end adapters through the first opening, while the primary second end of the one of the plurality of the flat tube adapters is inserted into the header.

In one embodiment, the heat exchanger further comprises fins between the plurality of flat tubes, wherein the fins are adjacent to the first ends of the plurality of tube end adapters.

In one embodiment, the non-circular shape cross-sections of the first ends each have two oppositely arranged short sides and two oppositely arranged long sides, wherein the primary second openings of the primary second ends are shifted towards one of the short sides of the respective first ends in a direction perpendicular to the extension axis, wherein the primary second openings of the primary second ends of the subsequent flat tubes of the plurality of flat tubes are shifted in opposite directions.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described in greater detail below with reference to the drawings. In the drawings:

FIG. 1 shows a tube end adapter in a perspective view;

FIG. 2 shows a cross-section view of the tube end adapter of FIG. 1;

FIG. 3 shows another cross-section view of the tube end adapter of FIG. 1;

FIG. 4 shows a heat exchanger with a tube end adapter;

FIG. 5 shows a cross-section view of the heat exchanger of FIG. 4;

FIG. 6 shows a header adapted to receive a tube end adapter;

FIG. 7 shows schematically a heat exchanger with end tube adapters attached to a header;

FIG. 8a shows an example of a second end of a tube end adapter before fixing to an external element;

FIG. 8b shows the example of the second end of the tube end adapter of FIG. 8a after fixing to the external element;

FIG. 9 shows a tube end adapter fixed directly to a fluid tank;

FIG. 10 shows another example of a tube end adapter;

FIG. 11 shows another example of a tube end adapter;

FIG. 12 shows another example of a tube end adapter;

FIG. 13 shows another example of a tube end adapter; and

FIG. 14 shows another example of a tube end adapter.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a tube end adapter 10 in a perspective view, with FIG. 2 and FIG. 3 presenting select cross-sections thereof. The tube end adapter 10 includes a first end 20 and a primary second end 30. A fluid channel 11 extends therebetween along an extension axis Z1 so that the fluid can flow between the first end 20 and the primary second end 30. The first end 20 has a first opening 21 and a non-circular shape cross-section. The first end 20 is adapted to receive a flat tube of a corresponding cross-section shape. The primary second end 30 has a primary second opening 31 and a rounded shape cross-section.

In one embodiment, the first end 20 extends from the first opening 21 towards the primary second opening 31, with the tube end adapter 10 maintaining the non-circular shape cross-section throughout the first end 20.

In one embodiment, the primary second end 30 extends from the primary second opening 31 towards the first opening 21, with the tube end adapter 10 maintaining the rounded shape cross-section throughout the primary second end 30.

In one embodiment, the fluid channel 11 includes an intermediate section 35 configured to transition the tube end adapter 10 between the non-circular shape cross-section of the first end 20 and the rounded shape cross-section of the primary second end 30. In other words, the intermediate section 35 gradually changes shape from the non-circular shape cross-section of the first end 20 to the rounded shape cross-section of the primary second end 30.

In one embodiment, the non-circular shape cross-section of the first end 20 has two oppositely arranged short sides 23 and two oppositely arranged long sides 24. This shape can correspond to analogously shaped flat tube 41.

In one embodiment, the primary second opening 31 of the primary second end 30 is shifted towards one of the short sides 23 of the first end 20 in a shift direction Z2 perpendicular to the extension axis Z1. In other words, the geometrical center of the primary second opening 31 will be offset with respect to the geometrical center of the first opening 21 when viewed along the extension axis Z1.

In one embodiment, the primary second end 30 has a circular cross-section.

FIG. 4 shows a heat exchanger 40 with a plurality of tube end adapters 10, in this case two visible for clarity. The heat exchanger 40 includes a plurality of flat tubes 41 for a heat exchange fluid, stacked one over another.

The heat exchanger 40 includes also a tube header 42 (shown in FIG. 6 and schematically in FIG. 7) with a plurality of header openings 43 of rounded shape corresponding to the rounded shape cross-sections of the primary second ends 30 of the plurality of tube end adapters 10.

Each of the plurality of flat tubes 10 is inserted into the first end 20 of one of the plurality of the tube end adapters 10 through the first opening 21, while the primary second end 30 of the one of the plurality of the flat tube adapters 10 is inserted into the tube header 42.

In one embodiment, the heat exchanger 40 includes fins 47 in-between the plurality of flat tubes 41. The fins 47 can be adjacent to the first ends 20 of the plurality of tube end adapters 10. In other words, the fins 47 can extend up to the first ends 20 of the tube end adapters 10 along the flat tubes 41.

The non-circular shape cross-sections of the first ends 20 each can have two oppositely arranged short sides 23 and two oppositely arranged long sides 24, wherein the primary second openings 31 of the primary second ends 30 can be shifted towards one of the short sides 23 of the respective first ends 20 in a shift Z2 direction perpendicular to the extension axis Z1. The primary second openings 31 of the primary second ends 30 of the subsequent flat tubes can be shifted in opposite directions, e.g. alternatively to one side and to another side.

FIG. 5 shows a cross-section view of the heat exchanger of FIG. 4, in particular how the flat tube 41 is located within the first end 20 and how it corresponds in shape to said first end 20.

FIG. 6 shows an example of an elongated tube header 42 adapted to receive a tube end adapter 10. It can be seen that the header openings 43 can be alternately shifted to the sides of the tube header 42 along its axis of elongation. In this manner, the flat tubes 41 can be arranged at close distance with respect to each other over the length of the tube header 42. The header openings 43 have a shape corresponding to a rounded shape cross-section of the primary second ends 30, contributing to a more robust and secure connection.

FIG. 7 shows a heat exchanger 40 with end tube adapters 10 attached to a schematically depicted tube header 42, with the primary second ends 30 being inserted into header openings 43.

FIG. 8a shows an example of a primary second end 30 of a tube end adapter 10 before fixing to an external element. FIG. 8b shows the example of the second end of the tube end adapter of FIG. 8a after fixing to the external element. The primary second end 30 can be formed as a part of an annular snap joint, with its counterpart 48 being a part of a header plate 44, a tank 45 for a fluid or another part of the fluid loop. A seal 49 can be placed between the components to prevent leakage.

FIG. 9 shows a tube end adapter 10 fixed directly to a fluid tank 45. The tube end adapter 10 and the fluid tank 45 can be both plastic, both metal, or one of them can be plastic while the other is metal.

FIG. 10 shows another example of a tube end adapter 10, where the primary second end 30 is upset before the element to which it is attached. The tube end adapter 10 can be connected in this manner to the tube header 42, or alternatively directly to the fluid tank 45. An O-ring 50 can be provided from the opposite side of those elements for sealing. The tube end adapter 10 can be brazed to the flat tube 41. This design allows to avoid brazing connection between the tube end adapter 10 and the tube header 42 or the fluid tank 45, which can allow simplified replacement of flat tubes 41 from the heat exchanger 10

FIG. 11 shows another example of a tube end adapter 10, where the primary second end 30 is upset before the element to which it is attached. The tube end adapter 10 can be connected in this manner to the tube header 42, or alternatively directly to the fluid tank 45. An O-ring 50 can be provided before those elements for sealing. The tube end adapter 10 can be brazed to the flat tube 41. This design allows to avoid brazing connection between the tube end adapter 10 and the tube header 42 or the fluid tank 45, which can allow simplified replacement of flat tubes 41 from the heat exchanger 10

FIG. 12 shows another example of a tube end adapter 10. In one embodiment, the tube end adapter 10 further comprises a secondary second end 36 having a secondary second opening 37 with a rounded shape cross-section, the tube end adapter 10 extending additionally between the first end 20 and the secondary second end 36 to enable fluid flow therebetween.

FIG. 13 shows another example of a tube end adapter 10. In one embodiment, the tube end adapter 10 further comprises a secondary second end 36 having a secondary second opening 37 with a rounded shape cross-section, the tube end adapter 10 extending additionally between the first end 20 and the secondary second end 36 to enable fluid flow therebetween. The tube end adapter 10 can have an intermediate section 35 configured to transition the tube end adapter 10 between the non-circular shape cross-section of the first end 20 and the rounded shape cross-sections of the primary second end 30 and the secondary second end 36.

FIG. 14 shows another example of a tube end adapter 10, in which the O-ring 50 is inserted with the tube header 42 or the fluid tank 45.

It is to be noted that embodiments shown in FIGS. 12 and 13, in particular the way the primary second end 30 and secondary second end 36 are connected to the tube header 42 or fluid tank 45, can be carried out according to any of the examples shown in the context of FIGS. 9-11 and 14.

The tube end adapter 10 can be made of metal, plastic or of elastic material.

By means of the invention, the strength of the tube-to-header joint is improved.

Round tank or header openings 43 are easier to manufacture than slots in the shape corresponding to the flat tubes 41. The brazing can be more consistent, while the tube headers 42 can be narrower.

The heat exchanger 40 can be for example a radiator, a condenser, a battery cooler, a chiller, an evaporator or a heater core.

The tube end adapter 10 can have a thicker cross section material for added strength in the gap between the flat tube 41 and the header 42. This can help with resistance to vibration, thermal expansion and contraction.

Also, the solution can help during pressure cycle test giving additional strength at the end of the flat tube when there is limited support from the fins 47 at the corners. Additional support is provided to the flat tubes 41 during pressure burst test.

The solution allows the fins 47 to cover the entire surface of the flat tube 41 between the tube end adapters 10 giving increased support. This further helps with resistance to vibration, thermal expansion and contraction, and tube ballooning.

The area of the header 42 can be smaller compared to headers directly receiving flat tubes 41, which leads to reduced separation forces, smaller crimps. Retention can be carried out using fasteners or snap-in features.

Using annular seals allows unconstrained expansion and contraction, so with the tube end adapter 10 stress can happen at the interface between the header 43/fluid tank 45 and the core.

The solution allows utilization of full round or considerably round fluid tanks 45, thereby potentially reducing plastic material thickness and need for additional support structures. Full round one-piece aluminum element can also be utilized, for example in case of condensers.

Using annular sealing and snap in features allows to avoid brazing or crimping at interface between the fluid tank 45 and the tube end adapter 10.

The solution allows for easier recyclability, reuse of tanks or heat exchange cores.

The solution allows dispensing with tube inserts.

Compared to slots for flat tubes 41, round tank or header openings 43 are easier to manufacture, have better brazeability and allow for reduction of distortion at the tube inlet for better flow and lower pressure drop.

Claims

1. A tube end adapter for a fluid, comprising a first end, a primary second end and a fluid channel extending therebetween along an extension axis so that the fluid can flow between the first end and the primary second end, the first end having a first opening and a non-circular shape cross-section and being adapted to receive a flat tube of a corresponding cross-section shape, with the primary second end having a primary second opening and a rounded shape cross-section.

2. The tube end adapter according to claim 1, wherein the first end extends from the first opening towards the primary second opening, with the tube end adapter maintaining the non-circular shape cross-section throughout the first end.

3. The tube end adapter according to claim 1, wherein the primary second end extends from the primary second opening towards the first opening, with the tube end adapter maintaining the rounded shape cross-section throughout the primary second end.

4. The tube end adapter according to claim 1, wherein the primary second end has a circular cross-section.

5. The tube end adapter according to claim 1, wherein the non-circular shape cross-section of the first end has two oppositely arranged short sides and two oppositely arranged long sides, wherein the primary second opening of the primary second end is shifted towards one of the short sides of the first end in a direction perpendicular to the extension axis.

6. The tube end adapter according to claim 1, wherein the fluid channel includes an intermediate section configured to transition the tube end adapter between the non-circular shape cross-section of the first end and the rounded shape cross-section of the primary second end.

7. The tube end adapter according to claim 1, wherein the primary second end includes an annular snap joint.

8. The tube end adapter according to claim 1, wherein the primary second end is upset.

9. The tube end adapter according to claim 1, made of metal.

10. The tube end adapter according to claim 1, made of plastic.

11. The tube end adapter according to claim 1, made of elastic material.

12. The tube end adapter according to claim 1, further comprising a secondary second end having a secondary second opening with a rounded shape cross-section, the tube end adapter extending additionally between the first end and the secondary second end to enable fluid flow therebetween.

13. The tube end adapter according to claim 12, further comprising an intermediate section configured to transition the tube end adapter between the non-circular shape cross-section of the first end and the rounded shape cross-sections of the primary second end and the secondary second end.

14. A heat exchanger, comprising: a plurality of flat tubes for a fluid;a plurality of tube end adapters for a fluid, each includinga first end, a primary second end and a fluid channel extending therebetween so that the fluid can flow between the first end and the primary second end, the first end having a first opening and a non-circular shape cross-section and being adapted to receive a flat tube of a corresponding cross-section shape, with the primary second end having a primary second opening and a rounded shape cross-section;a tube header with a plurality of header openings of rounded shape corresponding to the rounded shape cross-sections of the primary second ends of the plurality of tube end adapters;wherein each of the plurality of flat tubes is inserted into the first end of one of the plurality of the tube end adapters through the first opening, while the primary second end of the one of the plurality of the flat tube adapters is inserted into the header.

15. The heat exchanger according to claim 14, further comprising fins between the plurality of flat tubes, wherein the fins are adjacent to the first ends of the plurality of tube end adapters.

16. The heat exchanger according to claim 14, wherein the non-circular shape cross-sections of the first ends each have two oppositely arranged short sides and two oppositely arranged long sides, wherein the primary second openings of the primary second ends are shifted towards one of the short sides of the respective first ends in a direction perpendicular to the extension axis, wherein the primary second openings of the primary second ends of the subsequent flat tubes of the plurality of flat tubes are shifted in opposite directions.