FR2904400A1 - TRANSITION ASSEMBLY BETWEEN HEAT EXCHANGER AND EXTERNAL FLOW CIRCUIT, HEAT EXCHANGER, AND METHOD FOR MANUFACTURING THE TRANSITION ASSEMBLY - Google Patents

Abstract

The invention relates to a transition assembly for connecting a heat exchanger to an external flow circuit. The assembly includes a fluid connection tube (40) and a transition tube (50). Their ends are dimensioned so that one tube can be inserted into the other. A portion (60) of the outer tube may then be deformed to retain the inner tube. The ends can be shaped by conventional methods such as stamping. Application field: evaporators, capacitors, etc.

Description

The invention relates to heat exchangers, and more particularly

  improved transition assemblies for heat exchangers, as well as methods for producing a heat exchanger and a transition assembly. Many heat exchangers currently used, for example, as evaporators and condensers for stationary refrigeration systems, are based on a construction that includes fluid connections to external flow circuits for at least one of the fluids passing through the heat exchanger such as, for example, a refrigerant. In general, a fluid to be heated and / or cooled flows from an external source to the heat exchanger through an external flow circuit. Once the fluid has passed through the heat exchanger, the fluid exits to another external flow circuit. The external flow circuits can be connected to the heat exchanger by brazing if the flow circuit and the heat exchanger are made of materials that are easily brazed to one another; however, if this is not the case, fluid connections in the form of transition assemblies are used to connect the external sources to the inlet and outlet of the heat exchanger.

  Heat exchangers are often made from materials specifically selected to increase the heat transfer rate in the heat exchanger. However, the materials chosen for the heat exchanger are not the same as those for the external flow circuits and / or the transition assemblies. If different materials are chosen for the constituents, the constituents can expand and contract to different degrees. This effect becomes particularly important during assembly of the heat exchanger and transition assemblies. In particular, the transition assemblies are generally brazed to the heat exchanger by a process of subjecting the components to thermodynamic conditions sufficient to melt the solder and bond the components. If the heat exchanger and transition assemblies are made of materials such as aluminum and stainless steel, the aluminum components expand more than the stainless steel components. Accordingly, if the components are not properly oriented or not provided with templates holding the components together, they can separate from each other during the brazing process. In particular, one of the components may detach from the other component and fall under the effect of its own weight if they do not have an appropriate orientation. A similar disadvantage of this method is also that the solder may not remain at the desired location during the brazing process if the components are not in a proper orientation.

According to one form of the invention, there is provided a transition assembly for connecting a heat exchanger to an external flow circuit. The transition assembly includes a fluid connection tube extending from the heat exchanger. The fluid connection tube 25 comprises a body extending from the heat exchanger having a first inner cross-sectional area and an extended end having a second inner cross-sectional area which is larger than the first cross-sectional area. Inner transverse. The transition assembly also includes a transition tube having a transition end, a mating end, and a body portion extending between the transition end and the mating end. The body portion has a first outer cross sectional area and the transition end has a second outer cross sectional area which is larger than the first outer cross sectional area. The transition end substantially fits into the extended end and an edge portion of the extended end is deformed to retain the transition end in the extended end.

In one form of the invention, there is provided a heat exchanger. The heat exchanger comprises two spaced apart, generally parallel manifolds, a plurality of generally parallel spaced tubes extending between the manifolds and in fluid communication with the interior thereof, and a transition assembly. The transition assembly includes a fluid connection tube and a transition tube, the transition tube extending from an end or a side of one of the manifolds. The fluid connection tube comprises a body extending from the heat exchanger, having a first inner cross-sectional area and an extended end having a second inner cross-sectional area which is larger than the first cross-sectional area. Inner transverse. The transition tube has a transition end, a coupling end, and a body portion extending between the transition end and the coupling end. The body portion has a first outer cross-sectional area and the transition end has a second outer cross-sectional area that is larger than the first outer cross-sectional area. The transition end fits substantially in the extended end. An edge portion of the extended end is deformed to retain the transition end in the extended end.

In one form, the fluid connecting tube and the transition tube are brazed together with a brazing material. In one form, the brazing material is placed on the inside of the fluid connection tube.

In one form, the fluid connection tube is made of aluminum and the transition tube is made of stainless steel. In one form, the edge portion is deformed at a single location to retain the transition end in the extended end. In one form, the entire edge portion is deformed to retain the transition end in the extended end.

In one form, the body portion has a third inner cross-sectional area and the mating end has a fourth inner cross-sectional area which is larger than the third inner cross-sectional area.

In one form, the cross-sectional areas are circular. According to one form of the invention, there is provided a method of manufacturing a transition assembly for connecting a heat exchanger to an external flow circuit.

The assembly comprises a fluid connection tube and a transition tube. The fluid connection tube comprises a body and an extended end. The transition tube has a transition end, a mating end, and a body portion extending between the transition end and the mating end. The method comprises the steps of: inserting the transition end into the extended end of the fluid connecting tube so that the transition end is substantially enclosed in the extended end; deforming an edge of the extended end to retain the transition end within the extended end; and brazing the assembly to create a substantially fluid tight connection between the fluid connection tube and the transition tube.

In one form, the method further comprises the step of inserting a brazing material into the extended end of the fluid connection tube prior to insertion of the transition end.

In one form, the step of inserting a solder material comprises inserting a sized solder ring to fit into the extended end. In one form, the soldering step of the assembly is performed by soldering under a controlled atmosphere.

In one form, the transition tube is oriented in a downward direction relative to the force of weightlessness during the soldering step of the assembly. In one form, the method further comprises the steps of providing the fluid connecting tube of the body having a first inner cross-sectional area and the extended end having a second inner cross-sectional area and providing the tube transitional portion of the body portion having a first outer cross-sectional area and the transition end having a second outer cross-sectional area that is larger than the first outer cross-sectional area. In one form, the cross-sectional areas are circular.

In one form, the method further comprises the step of inserting an end of an outflow circuit into the mating end of the transition tube to create a substantially fluid tight connection between the tube. transition and the external flow circuit.

The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting example and in which: FIG. 1 is a partially broken away perspective view of a heat exchanger and transition assemblies; FIG. 2 is a transition assembly; FIG. 3 is a transition assembly; FIG. 4 is a transition assembly; a cross-sectional view of one before a deformation; a cross-sectional view of one after a form of deformation; and a cross-sectional view of one after another form of deformation and a connected external flow circuit. The invention will be described hereinafter as a condenser or an evaporator for a fixed refrigeration system. It should be understood, however, that the invention can be applied to condensers used in other contexts, for example, a condenser for a vehicle. The invention is also useful in any of the many other types of heat exchangers that use gaskets or transition assemblies to connect the heat exchanger to external fluid flow circuits, such as stainless steel or copper ducts. Accordingly, no limitation to any particular use is provided unless otherwise indicated.

With reference to FIG. 1, a typical heat exchanger of the type concerned comprises spaced apart parallel plates 10, 12 between which a plurality of flattened tubes 14 extend. The tubes 14 are spaced from one another and their ends are brazed or welded, by hard or soft welding, and extend through slots, not shown, in the manifolds 10 and 12 so as to be in fluid communication with the interior of the collectors 10, 12. In this regard, it should be noted that the term "collector" as used herein refers generally to collector plates 10, 12, collectors 10, 12 on which reservoirs are mounted, or to built-in collector and reservoir constructions. known in the art, for example, formed of tubes or by various methods of lamination. Side pieces 18, 20 may optionally frame the respective sides of the heat exchanger construction and extend between the manifolds 10, 12, to which they are usually mechanically connected as well as by metallurgical bonds. Conventional serpentine fins 22 extend between the spaced tubes 14, and between the outermost tube 14 and adjacent one, side plates 18, 20, but these fins could be of any size. other suitable fin, including plate type fins. As is well known, the fins 22 may be formed of various materials. Typical examples include aluminum, copper and brass. However, other materials can also be used, depending also on the desired heat exchange efficiency and effectiveness requirements of a particular application. In a highly preferred embodiment of the invention, all the parts just described, except, where appropriate, the tanks 16 which may be formed of plastic material, are formed of aluminum or an alloy of and aluminum are brazed at appropriate locations so that an entire assembly as illustrated in FIG. 1 can be set up in a brazing furnace and the components all brazed together. In the usual case, prior to brazing, a suitable template is used to construct a sandwich formed of the tubes 14 alternating with the serpentine fins 22 and capped at each end by the side plates 18 and 20. The collectors 10, 12 are adjusted on the ends of the tubes 14 and, in the usual case, the side plates 18 and 20 can be mechanically connected to the collectors 10, 12, usually by folding tabs, located on the side plates 18, on the corresponding ends of the collectors The heat exchanger also includes two transition assemblies 30 and 32. The parts and operation of the transition assemblies 30 and 32 can be seen in more detail in the embodiments shown in FIGS. 2-4. .

In particular, with reference to FIG. 2, there is shown an embodiment of the transition assembly 30 before deformation. The transition assembly 30 includes a fluid connection tube 40 extending from the heat exchanger. The fluid connection tube 40 comprises a body 42 extending from the heat exchanger, having a first inner cross-sectional area, which, as shown in FIG. 2, is based on the inside diameter (ID1) of the body 42 because the cross-section of the body 42 is circular in shape. The fluid connection tube 40 also includes a prolonged end 44 having a second internal cross-sectional area which, as shown in FIG. 2, is based on the inner diameter (ID2) of the extended end 44, since the section 15 transverse of the prolonged end 44 is circular in shape. The second inner cross-sectional area is larger than the first inner cross-sectional area, as illustrated by the larger diameter ID2. The transition assembly 30 also includes a transition tube 50. The transition tube 50 has a transition end 52, a coupling end 54, and a body portion 56 extending between the transition end 52 and the transition end 52. the coupling end 54. The body portion 56 has a first outer cross-sectional area which, as shown in FIG. 2, is based on the outside diameter (OD1) of the body portion 56 as the cross section of the body part is circular in shape. The transition end 52 has a second outer cross-sectional area which, as illustrated in FIG. 2, is based on the outer diameter (OD2) of the transition end 52 because the latter is circular in shape. The second outer cross-sectional area is larger than the first outer cross-sectional area, as illustrated by the larger OD2 diameter.

Although the above description refers to inner and outer diameters for the respective cross-sectional areas, which are often preferred, it should be understood that other shapes are also contemplated. Therefore, the cross-sectional areas are not limited to the respective end diameters. For example, the ends may take the form of ovals or other shapes and thus the ends will not have constant diameters, but will still have a measurable cross sectional area for the respective pieces. Further, in a preferred embodiment, the outer diameter OD2 of the transition end 52 is substantially equal to the inner diameter ID2 so that the transition end 52 fits tightly into the extended end 44. Independently of the shape, the transition end 52 and the extended end 44 are sized and configured so that the transition end 52 fits substantially into the extended end 44. In this position, an edge portion 60 the extended end may be deformed to retain the transition end 52 in the extended end 44. The edge portion 60 is shown in Figure 2 prior to deformation. The edge portion 60 is then deformed so that it contacts the transition end 52 and prevents the transition tube 50 from falling back from the fluid connection tube 40. In particular, with reference to FIG. 3, the edge portion 60 may be deformed at a location 62, for example by crimping. Another method of deforming the edge portion 60 is to fold the entire edge portion 60, as shown in FIG. 4. However, those skilled in the art should understand that other forms of deformation can also be used to retain the transition tube 50 in the fluid connection tube 40.

The transition assembly 30 preferably comprises solder material or solder to form a fluid tight connection between the connecting tube 40 and the transition tube 50. The solder may be placed on the outer side of these two 40 and 50 or, in a preferred embodiment, placed inside the fluid connection tube 40. In a highly preferred embodiment, as illustrated in FIG. 2, the solder or brazing material is a ring 64 of solder 10 placed inside the tube 40 of fluid connection and adjacent to the tube 50 of transition. The solder may take many forms known to those skilled in the art such as, for example, Nocolok core solder rings.

Those skilled in the art should understand that the extended end 44 and the transition end 52 can be fabricated using conventional techniques. For example, a technique known in the prior art is called stamping, whereby the ends are bent and / or configured using known tools and procedures. Other suitable end-forming methods are also contemplated, for example by brazing or welding pieces of tubes of different sizes for the respective heat exchanger and transition tubes. It should also be understood that the coupling end 54 of the transition tube 52 can also be shaped similarly to the other ends, as shown in FIG. 3. However, it is not necessary that the coupling end 54 take this form.

The coupling end 54 is used to connect the transition assembly to an external flow circuit 70, as illustrated in FIG. 4 which is usually one of many known forms for a fluid coupling or conduit. . In one form, as seen in FIG. 4, the flow outer circuit 70 fits into the coupling end 54 and can be brazed or otherwise affixed thereto. In addition, the coupling end 54 and the flow outer circuit 70 can be dimensioned and configured in the same manner as the extended end 44 and the transition end 52 so that the coupling end 54 may be deformed to retain the outer flow circuit 70 within the coupling end 54 (not shown). The fluid connection tube 40, the transition tube 50 and the flow external circuit 70 may all be formed of conventional materials known to those skilled in the art. In a highly preferred embodiment, the fluid connection tube 40 is made of aluminum, the transition tube 50 is made of stainless steel and the outflow circuit 70 is made of copper.

During assembly, the transition end 52 is inserted into the extended end 44 of the fluid connection tube 40 so that the transition end is substantially enclosed in the extended end 44, as shown in FIG. 2. It is not necessary that the transition end 52 be fully within the extended end, but to a degree just sufficient for the edge portion 60 to be deformable to retain the tube. transition 50 in the tube 40 of fluid connection. The transition assembly 30 is then bonded using a suitable technique to create a substantially fluid-tight connection between the fluid connection tube 40 and the transition tube 50. In one form, the tubes 40, 50 are brazed to the fluid. one to another. This can be achieved by using a solder or solder material inserted into the fluid connection tube 40 or placed outside the fluid connection tube 40. In a preferred embodiment, solder 64 is inserted into the fluid connection tube 40 and the transition assembly 30 is subjected to thermodynamic conditions sufficient to melt the solder ring and create a substantially sealed connection 2904400 12 to the fluid between the connecting tube of the fluid 40 and the transition tube 50. In a highly preferred embodiment, the brazing is performed using brazing under a controlled atmosphere.

In one embodiment, the ends 44 and 52 may be sized and configured such that the transition end 52 sandwiches the solder ring 64 between this transition end 52 and the inside of the extended end 44. before entering the body 42 10 of the tube 40 fluid connection. Therefore, once the extended end 44 is deformed, the solder ring 64 and the transition end will virtually no longer move regardless of the orientation of the transition assembly 30 and the materials used therein .

Usually, during the brazing process, if different materials are used for each tube, the tubes expand and contract to different degrees and sizes. It is therefore possible that the end of the heat exchanger will expand further than the transition end. If the present transition assembly were not used, the fluid connection tube 40 and the transition tube 50 could separate. The separation can very well take place in a conventional assembly in which gravity collapses the transition tube of the fluid connection tube. However, the present assembly allows the tube to be oriented in any way while minimizing the risk of tube separation. In addition, the transition assembly may be previously assembled prior to connection to the fluid connection tube. For example, with reference to FIG. 1, it can be seen that the transition sets can have any orientation, since the parts of the transition sets are held in place by the structure of the sets themselves.

In particular, the transition assembly 30 has a downward orientation while the transition assembly 32 is turned sideways. These sets can be brazed in this position without having to worry about a separation of the parts under the effect of their own weight and a thermal expansion of the parts.

It goes without saying that many modifications can be made to the transition assembly and to the heat exchanger described and shown without departing from the scope of the invention.

Claims (24)

  A transition assembly for connecting a heat exchanger to an external flow circuit (70), the assembly (30) being characterized in that it comprises: a fluid connection tube (40) extending from the heat exchanger and comprising a body (42) extending from the heat exchanger and having a first inner cross-sectional area, and an extended end (44) having a second larger inner cross-sectional area (44). that the first area in inner cross section; and a transition tube (50) having a transition end (52), a coupling end (54) and a body portion (56) extending between the transition end and the coupling end, the body portion having a first outer cross-sectional area and the transition end having a second outer cross-sectional area which is larger than the first outer cross-sectional area, the transition end substantially adjusting in the cross-sectional area; extended end, an edge portion (60) of the extended end being deformed to retain the transition end in the extended end.   2. Transition assembly according to claim 1, characterized in that the fluid connection tube and the transition tube are brazed to each other with solder material (64).   3. Transition assembly according to claim 2, characterized in that the brazing material is placed on the inside of the fluid connection tube.   4. Transition assembly according to claim 1, characterized in that the fluid connection tube is made of aluminum and the transition tube is made of stainless steel.   The transition assembly of claim 1, characterized in that the edge portion is deformed at a single location to retain the transition end in the extended end.   The transition assembly of claim 1, characterized in that the entire edge portion is deformed to retain the transition end in the extended end.   The transition assembly of claim 1, characterized in that the body portion has a third area in inner cross section and the mating end has a fourth area in inner cross section which is larger than the third area. in inner cross section.   Transition assembly according to claim 1, characterized in that the cross-sectional areas are circular.   9. Heat exchanger, characterized in that it comprises: two spaced collectors and generally parallel (10, 12); A plurality of spaced apart, generally parallel tubes (14) extending between the collectors and in fluid communication with the interior of these collectors; and a transition assembly (30), comprising a fluid connection tube (40) and a transition tube (50), the transition tube extending from one of the manifolds, the fluid connecting tube comprising a body (42) extending from the heat exchanger and having a first inner cross-sectional area, and an extended end (44) having a second inner cross-sectional area which is larger than the first cross-sectional area cross-section, the transition tube having a transition end (52), a coupling end (54), and a body portion (56) extending between the transition end and the coupling end; a body portion having a first outer cross-sectional area and the transition end having a second outer cross-sectional area which is larger than the first outer cross-sectional area, the outermost cross-sectional area; A transition portion substantially adjusts in the extended end, an edge portion (60) of the extended end being deformed to retain the transition end within the extended end.   10. Heat exchanger according to claim 9, characterized in that the fluid connecting tube and the transition tube are brazed to each other with brazing material (64).   11. Heat exchanger according to claim 10, characterized in that the brazing material is placed on the inside of the fluid connection tube.   12. Heat exchanger according to claim 9, characterized in that the fluid connection tube is made of aluminum and the transition tube is made of stainless steel.   Heat exchanger according to claim 9, characterized in that the edge portion is deformed at a single location to retain the transition end within the extended end.   The heat exchanger of claim 9, characterized in that the entire edge portion is deformed to retain the transition end within the extended end.   A heat exchanger according to claim 9, characterized in that the body portion has a third area in inner cross-section and the mating end has a fourth area in inner cross section which is larger than the third area. in inner cross section.   16. Heat exchanger according to claim 9, characterized in that the cross-sectional areas are circular. 35   A method of manufacturing a transition assembly (30) for connecting a heat exchanger to an outboard flow circuit (70), the assembly comprising a fluid connection tube (40) and a tube ( 50), the fluid connecting tube comprising a body (42) and a prolonged end (44), the transition tube having a transition end (52), a coupling end (54) and a portion body (56) extending between the transition end and the mating end, the method being characterized in that it comprises the steps of: inserting the transition end into the extended end the fluid connecting tube so that the transition end is substantially enclosed in the extended end; deforming an edge of the extended end to retain the transition end within the extended end; and soldering the assembly to create a substantially fluid tight connection between the fluid connection tube and the transition tube.   18. The method of claim 17, further comprising the step of inserting solder material (64) within the extended end of the fluid connection tube prior to insertion of the transition end.   19. The method of claim 18, characterized in that the step of inserting a solder material comprises inserting a solder ring (64) sized to fit into the extended end.   20. The method of claim 17, characterized in that the brazing step of the assembly is performed by brazing under a controlled atmosphere.   21. The method of claim 17, characterized in that the transition tube is oriented in a downward direction relative to the force of gravity during the soldering step of the assembly. 35   22. The method of claim 17, further comprising the steps of: providing the fluid connection tube of the body (42) having a first inner cross-sectional area and the extended end (44) having a second internal cross-sectional area and providing the transition tube of the body portion having a first outer cross-sectional area and the transition end having a second outer cross-sectional area which is more large than the first area in external cross section. 10   23. The method of claim 22, characterized in that the cross-sectional areas are circular.   24. The method of claim 17, further comprising the step of inserting an end of an outflow circuit (70) into the mating end of the transition tube to creating a substantially fluid tight connection between the transition tube and the external flow circuit.