JP5539742B2 - Heat exchange insert for heat exchanger - Google Patents

Description

  The present invention relates to a heat exchange insert for a heat exchanger and a heat exchanger comprising such an insert.

  In particular, the present invention relates to a heat exchanger primarily for automobiles, comprising a tube core separated by a gap and a plurality of corrugated heat exchange inserts. The plurality of corrugated heat exchange inserts is in the form of a metal strip that is folded to form a series of substantially flat portions. Each flat is disposed between two tubes and is connected two by two by one bend joint that is sized to fit the gap between the tubes.

  The function of the heat exchanger is to allow heat exchange between the fluid circulating in the tube and the external fluid passing through the heat exchanger. If it is desired to improve the performance of heat exchange between the fluid circulating in the tube and the external fluid, a means that enables an increase in the surface area of heat exchange between the external fluid and the fluid circulating in the tube Is generally provided in the heat exchanger.

  Accordingly, such heat exchangers typically include one or more rows of aligned tubes through which cooling fluid circulates. A collection of these tubes is generally called a core. The function of such a heat exchanger is to allow heat exchange between the cooling fluid circulating in the tube and the fluid passing outside the heat exchanger.

  Thus, it is well known in the art to provide a heat exchanger with a plurality of heat exchange inserts that are generally corrugated in appearance, formed by a series of substantially flat portions that are connected two by two by one bend joint. is there. Typically, the corrugated insert is disposed between the two tubes so that a portion of the bent joint contacts the tube.

  Such a heat exchanger can be incorporated into, for example, an automobile air conditioner. In this case, the external fluid that passes through the heat exchanger is usually air that is blown into the automobile, and the cooling fluid is a refrigerant fluid. In this case, the heat exchanger aims to cool the air to be blown. Therefore, this heat exchanger is an evaporator.

  The circulation of the fluid in the air conditioning circuit is usually done by a compressor driven directly by the automobile engine.

  Currently, there is a need to reduce the weight of components used in automobiles. In particular, the heat exchanger is made of metal, in particular aluminum. In order to meet current demands, it is considered necessary to reduce the thickness of metal sheets used in the manufacture of such heat exchangers.

  The thickness of the metal sheet used is generally less than 70 μm for inserts and less than 270 μm for tubes. Such a reduction in thickness causes a disadvantage that the mechanical strength of the heat exchanger is lowered and the risk of promoting failure and deterioration is increased.

  The risk of degradation increases during the heat exchanger production stage, during the final manufacturing stage where various components are secured together, when holding pressure is applied to the tube and insert cores to ensure a good bond .

  Under such holding pressure, the tube and the insert core can be deformed and / or dislocated, resulting in failure due to leakage, for example, and reduced efficiency due to increased pressure loss, for example.

  The object of the present invention is to propose a new type of heat exchanger as described in the introduction, which has solved the above problems.

  The present invention provides an insert for a heat exchanger formed from a metal strip or sheet. Such an insert comprises at least a first zone having a first thickness and at least a second zone having a second thickness.

  The first thickness and the second thickness are set such that the second thickness is not less than 1.5 times and not more than 2 times the first thickness.

  In a preferred embodiment of the invention, the second zone defines a local thickening obtained by folding the metal strip over the first length, preferably at the end of the insert.

  It is particularly advantageous if the local thick part is thinned by rolling.

  Alternatively or in addition, the first zone is formed by locally thinning the metal strip by machining, rolling, stamping, or forming.

  Advantageously, the local thickness of the insert defines at least one transverse protrusion of a predetermined height, for example equal to the difference between the second thickness and the first thickness.

  The invention also relates to a heat exchanger comprising at least one insert as described above.

  In a preferred embodiment of the invention, the insert comprises two local thickenings provided on the same side or on two opposite sides.

  Preferably, the heat exchanger comprises at least one heat exchange tube disposed between at least two local wall thicknesses.

  In a variant, the heat exchange tube comprises at least one local deformation that can interact with the local thickening of the insert.

  Other features and advantages of the present invention will become apparent from consideration of the accompanying drawings and the following detailed description, which not only supplement the understanding of the present invention, but can also contribute to the definition of the present invention as appropriate.

It is a front view of the heat exchanger by this invention. It is a perspective view of a part of core of the heat exchanger of FIG. It is sectional drawing cut along line III-III of the core part of the heat exchanger of FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3 of a different embodiment according to the present invention. FIG. 5 is a perspective view of the embodiment of the insert of FIG. FIG. 3 is a cross-sectional view of another embodiment of the present invention taken along line III-III of the core portion of the heat exchanger of FIG.

  FIG. 1 is a front view of the heat exchanger 2. The heat exchanger 2 comprises a core of tubes 8 separated by a gap 12 in which a corrugated insert 10 is arranged.

  The corrugated insert 10 is in the form of a metal sheet or strip 20 that is folded to form a series of flat portions or substantially flat portions 22. Each flat portion 22 is disposed between two tubes 8 and is connected two by two by one bend joint 24 sized to fit the gap 12 defined between two successive tubes 8. .

  The heat exchanger 2 also includes a first collection ring 4 and a second collection ring 6 that receive one end and the other end of a fluid circulation tube 8 such as a refrigerant liquid or a cooling liquid, respectively. The tubes 8 are equally spaced from each other and are arranged in a row to form the core of the tube 8.

  The first collecting ring 4 is connected to an inlet manifold 14 connected to an air conditioning circuit through which a fluid such as a refrigerant liquid or a cooling liquid circulates, and the second collecting ring 6 is also connected to an outlet manifold connected to the air conditioning circuit. 16.

  Accordingly, the fluid exiting the upstream portion of the air conditioning circuit enters the inlet manifold 14, passes through the first tubular collection ring 4, circulates through the tube 8, and then reaches the second collection ring 6. The fluid then passes through the second collection ring 6 and exits from an outlet manifold 16 connected to the downstream portion of the air conditioning circuit.

  According to another embodiment, the heat exchanger 2 comprises a single collection ring. The single collection ring has two interior spaces formed by two collection chambers separated by an internal partition or juxtaposed so that the inlet manifold 14 and the outlet manifold 16 are individually disposed therein.

  The core of the tube 8 and the insert 10 is provided with two end plates 18 that hold the entire heat exchanger 2 and increase the strength.

  The present invention is also directed to a heat exchanger that does not include the end plate 18.

  The heat exchanger 2 enables heat exchange between an external fluid such as air passing through the inside thereof and a fluid circulating inside the tube 8 such as a refrigerant or a coolant.

  In the example of FIG. 1, the fluid circulating inside the tube 8 is a supercritical fluid such as carbon dioxide, also known as R744, or a subcritical fluid, such as a fluorine compound, which is a refrigerant fluid named R134a. be able to. Furthermore, the present invention can be used with other alternative fluids. The fluid circulating in the tube 8 may be a cooling fluid such as a fluid for cooling the heat engine of the automobile.

  FIG. 2 is a perspective view of a part of the core of the heat exchanger of FIG.

  FIG. 2 clearly shows the shape of the tube 8 and the insert 10 and their configuration relative to each other.

  As shown in FIG. 1, a corrugated heat exchange insert 10 is disposed between the two tubes 8.

  Each insert 10 is formed in the form of a bent metal sheet or strip made of, for example, an aluminum alloy. Each insert 10 includes a louver 26 formed by cutting a metal strip 20.

  The corrugated insert 10 is formed, for example, by continuous folding of a metal strip, also called a “flat band”. The insert 10 includes a series of flat portions 20 configured such that two adjacent flat portions 20 are connected to each other by a joint 24.

  An air flow F traverses the heat exchanger 2 and passes through the tube 8 and the core of the insert 10.

  Therefore, the heat exchanger 2 has an upstream surface that forms a surface where the air flow F enters the heat exchanger 2 and a downstream surface that forms a surface where the air flow F exits the heat exchanger 2.

  According to the present invention, the insert 10 also comprises a local thick portion 30. The local thick portion 30 can improve the strength of the insert 10 and thus contribute to the improvement of the strength of the heat exchanger 2.

  The two local thick portions 30 are preferably provided at both ends of the insert 10 in the direction in which the airflow F flows. Therefore, the first local thick portion 30 is located on the upstream surface of the heat exchanger 2, and the second local thick portion 30 is located on the downstream surface of the heat exchanger 2.

  In the first exemplary embodiment, the local thick portion 30 is formed by local bending, such as by bending over the first length A of the metal strip 20 comprising the insert 10. ing. Therefore, when the metal strip has the first thickness Th1, the local thick portion 30 has the second thickness Th2 equal to twice the first thickness Th1.

  Thus, the insert 10 will comprise a first zone having a first thickness Th1 and at least a second zone having a second thickness Th2.

  This embodiment makes it possible to have a first thickness Th1 that is less than or equal to twice the second thickness Th2.

  Further, for example, in order to define the first zone of thickness Th1 and the second zone of thickness Th2 such that the first thickness Th1 is thinner than the second thickness Th2, for example, rolling For example, the metal strip 20 can be locally thinned.

  In order to reduce the dimension of the local thick portion 30 and obtain the second thickness Th2, the local thick portion 30 is thinned by rolling, for example.

  According to this embodiment, the second thickness Th2 is preferably in the range of 1.5 to 2 times the first thickness Th1.

  Furthermore, the present invention allows the local thickened portion 30 to define a terminal abutment having a height h2 that is at least equal to the difference between the second thickness Th2 and the first thickness Th1. To do.

  Further, such a terminal contact portion is useful for holding the insert 10 in a predetermined position between the tubes 8. Specifically, as shown in FIG. 2, the insert 10 is held in the lateral direction, that is, in the direction of the flow of the air flow F perpendicular to the center plane.

  Alternatively, according to the second embodiment (not shown), the first portion of the insert 10 can be thinned to provide the local thickened portion 30 by machining. The first part of the insert 10 to be thinned is preferably located symmetrically with respect to the central plane of the tube 8 and the core of the insert 10. The central plane is a plane that is equidistant from the upstream surface and the downstream surface of the heat exchanger 2 and is parallel to the heat exchanger 2.

  The above configuration is illustrated in detail in FIG. 3, which is a cross-sectional view taken along line III-III of the core portion of the heat exchanger 2 of FIG.

  As shown in FIG. 3, the terminal contact portion is in contact with the end wall 40 of the tube 8. This contact is preferably made on the two smaller sides of the tube 8 connecting the two larger sides of the tube 8 in contact with the insert 10.

  By such holding, the insert 10 is arranged and held in a predetermined position, and when pressure is applied for assembling the heat exchanger 2, it cannot move between the tubes 8.

  According to the example of FIG. 3, the two local thick portions 30 are provided on the same side surface of the insert 10. In this embodiment, it is possible to provide two terminal abutting portions on both sides of the same tube 8 in the same cross section of the upstream surface and the downstream surface of the heat exchanger 2 and a plane perpendicular to the central plane.

  According to this example, the insert 10 is held at a predetermined position of the tube 8.

  According to another modified embodiment, two local thickenings 30 are provided on both sides of the insert 10. This is shown in detail in FIG. 4, which is a cross-sectional view taken along line IV-IV in FIG.

  As illustrated in FIG. 4, the end portion of the insert 10 located on the downstream surface includes a local thick portion 30 on the first side of the insert 10. The end portion of the insert 10 located on the upstream surface is provided with a local thick portion 30 on the second side of the insert 10 opposite to the first side.

  With such a configuration, alternating terminal contact portions are possible. When formed in this way, the insert 10 can be held in place between two adjacent tubes 8.

  FIG. 5 is a perspective view of the embodiment of the insert of FIG.

  The invention can be used in particular for heat exchangers for heating, ventilation and / or air conditioning equipment designed for motor vehicles such as evaporators, condensers, gas coolers or heat radiators.

  Furthermore, said example is related with the heat exchanger provided with the folding-type tube. However, the present invention is also directed to embodiments with tubes comprising plates or extruded tubes.

  The fluid circulation tube 8 is a “single channel” type. The tube 8 described herein is merely an example. In the present invention, other types of tubes can also be used as the fluid circulation tube 8. The present invention is also directed to embodiments in which the tube 8 includes an internal divider that defines a plurality of internal channels. Such tubes are commonly referred to as “multi-channel tubes”. The tube 8 is therefore known as a “multi-channel flat tube”.

  FIG. 6 shows an alternative embodiment of the present invention.

  This modification has the advantage of reducing the thickness of the tube 8 core. For this reason, the tube 8 includes a local deformation portion 32. The local deformation portion 32 can define a space suitable for receiving the local thick portion 30 of the insert 10.

  The local deformation portion 32 is preferably provided at the end portion 36 of the tube 8. The local deformation part 32 is made to coincide with the shape of the local thick part 30 so as to interact with the local thick part 30 of the insert 10.

  According to the example of FIG. 6, the tube 8 includes a central portion 34 having a thickness of e1 and two end portions 36 provided on both sides of the central portion 34. Each end 36 has a thickness of e2. The thickness e1 is equal to the value obtained by adding twice the height h2 of the end contact portion of the insert 10 to the thickness e2.

  The embodiment of FIG. 6 also shows a specific embodiment of the corrugated insert 10. According to this example, since the insert 10 includes two local thick portions 30 on each side, the insert 10 has a total of four local thick portions 30.

  Such an insert 10 is the result of double folding in the opposite direction, i.e. folding the metal strip over the first length (A) of the end of the insert 10 in two opposite directions. After this folding, the thickness of the folded double folded portion can be reduced by thinning, preferably by the above-described rolling.

  This embodiment has the same advantage that the insert 10 is retained in the core of the tube 8 when pressure is applied for mounting the heat exchanger 2.

  The present invention is not limited to an evaporator. The present invention is useful for all types of heat exchangers such as condensers, gas coolers, heat radiators and the like.

  The invention is not limited to the above-described embodiments described by way of example only, but also other modifications which those skilled in the art consider within the scope of the claims and all combinations of the various embodiments described above. Is included.

2 Heat exchanger 4 First collection ring 6 Second collection ring 8 Tube 10 Insert 12 Gap 14 Inlet manifold 16 Outlet manifold 18 End plate 20 Strip 22 Flat part 24 Bending joint 26 Louver 30 Local thick part 32 Local deformation Part 34 Center part 36 End part A First length F Airflow Th1 First thickness Th2 Second thickness e1 Center part thickness e2 End part thickness h2 Height

Claims (15)

In an insert (10) for a heat exchanger (2) formed from a metal strip (20),
Comprising at least a first zone having a first thickness (Th1) and at least a second zone having a second thickness (Th2) ;
One local thick part (30) is arranged on the first side of the insert (10), the other local thick part (30) is arranged on the second side of the insert (10),
The second side is located on the opposite side of the first side through the metal strip (20),
The insert (10) is characterized in that the local thick part (30) is formed so as to be able to make a terminal contact with the adjacent tube (8 ).   The insert (10) according to claim 1, characterized in that the second thickness (Th2) is not more than twice the first thickness (Th1).   The insert (10) according to claim 1 or 2, characterized in that the second thickness (Th2) is not less than 1.5 times the first thickness (Th1).   The second zone defines a local wall (30) formed by folding the metal strip (20) over a first length (A). 4. The insert (10) according to any one of items 3.   Insert (10) according to claim 4, characterized in that a local thick part (30) of the metal strip (20) is provided at the end of the insert (10).   Insert (10) according to claim 4 or 5, characterized in that the local thick part (30) is thinned by rolling.   The insert (10) according to any one of the preceding claims, characterized in that the first zone is formed by local thinning of the metal strip (20).   The insert (10) according to claim 7, characterized in that the local thinning is performed by machining.   9. The local thickness (30) of the insert (10) defines at least one transverse protrusion having a height (h2). The insert (10) according to.   10. The height (h2) of the local thick part (30) is equal to the difference between the second thickness (Th2) and the first thickness (Th1). Insert (10).   A heat exchanger (2) comprising at least one insert (10) according to any one of the preceding claims.   12. A heat exchanger (2) according to claim 11, characterized in that the insert (10) comprises two local thick parts (30) provided on the same side.   12. A heat exchanger (2) according to claim 11, characterized in that the insert (10) comprises two local thickenings (30) provided on its two opposite sides.   14. Heat exchanger (2) according to claim 12 or 13, characterized in that it comprises at least one heat exchange tube (8) arranged between at least two local wall thicknesses (30).   The heat exchange according to claim 14, characterized in that the heat exchange tube (8) comprises at least one local deformation (32) capable of interacting with the local wall (30) of the insert (10). Vessel (2).

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