Heat exchanger and corresponding production method

Abstract

Heat exchanger, and production method, including at least two plates of metal material, overlapping and reciprocally joined together so as to define a perimeter edge of the heat exchanger, and at least one circuit for the passage of a heat-carrier fluid defined by at least one or more heat exchange channels made between the plates.

Claims

1. A method to produce a heat exchanger (10, 10′), comprising at least two plates (11, 12) of metal material having a pre-defined shearing perimeter, overlapping and joined together so as to define a perimeter edge (13) beyond the shearing perimeter and at least one circuit (14) for the passage of a heat-carrier fluid defined by at least one or more heat exchange channels (15) made between said plates (11, 12), wherein said method comprises: at least one deposition step, to deposit on at least one of two plates (11, 12) a detaching material according to the shape and the path of the heat exchange circuit (14) to be obtained; the overlapping and hot rolling of said plates (11, 12) with in the middle the template of the circuit (14) made of detaching material; the introduction of a fluid under pressure from at least one aperture made on a perimeter edge (13) made by overlapping the plates (11, 12) and consequent deformation of at least one of the plates (11, 12) in correspondence with said detaching material, thus obtaining, by inflation, one or more channels (15) and at least one heat exchange portion (19, 19′) extending beyond the shearing perimeter and situated in proximity to the perimeter edge (13) of the heat exchanger, that is, at a minimum distance (D1) from said perimeter edge (13), cutting the plates (11, 12) along the shearing perimeter, resulting in an exposed aperture of the heat exchange portion (19, 19′), and closing the exposed aperture in a finishing step, thereby forming a closing edge (20, 20′) of the heat exchange portion (19, 19′).

2. The method as in claim 1, wherein said closing edge (20, 20′) is made by bending the perimeter edge (13) of the plates (11, 12).

3. The method as in claim 1, wherein said closing edge (20, 20′) is made by welding the plates (11, 12) in the finishing step in proximity to said perimeter edge (13) of the heat exchanger (10, 10′).

4. The method as in claim 1, wherein said closing edge (20, 20′) is made by gluing the plates (11, 12) in the finishing step in proximity to said perimeter edge (13), and subsequent shearing.

5. The method as in claim 1, wherein, to obtain said heat exchange portion (19, 19′), at least one strip of detaching material is disposed between said plates (11, 12) beyond the perimeter edge (13) of the heat exchanger (10, 10′).

6. A heat exchanger obtained with the method as in claim 1, comprising the at least two plates (11, 12) of metal material, overlapping and reciprocally joined together so as to define the perimeter edge (13) of the heat exchanger and the at least one circuit (14) for the passage of a heat-carrier fluid defined by the at least one or more heat exchange channels (15) made between said plates (11, 12), wherein said circuit (14) is provided with the at least one heat exchange portion (19, 19′) having the at least one closing edge (20, 20′) which is made in proximity to the perimeter edge (13) of the heat exchanger, that is, at a minimum distance (D1) from said perimeter edge (13) variable from about 3 mm to about 7 mm.

7. The heat exchanger as in claim 6, wherein the width (L1, L2) of said heat exchange portion (19, 19′) is greater than the width of a single heat exchange channel (15).

8. The heat exchanger as in claim 6, wherein said heat exchange portion (19′) is defined by at least one channelized area made on said heat exchange circuit (14) and provided with a series of branching points (17).

9. The heat exchanger as in claim 6, wherein said heat exchange portion (19) comprises one or more holes (21) for the inlet or outlet of the heat-carrier fluid to/from the heat exchanger.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

(2) FIG. 1 is a plan view of an embodiment of a heat exchanger according to the present invention;

(3) FIG. 2 is a three-dimensional view of a part of the heat exchanger of FIG. 1;

(4) FIG. 3 is a three-dimensional view of a variant of the heat exchanger of FIG. 1;

(5) FIG. 4 is a three-dimensional view of a part of a variant embodiment of a heat exchanger according to the present invention;

(6) FIG. 5 is a plan view of an embodiment of a heat exchanger of the state of the art.

(7) To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

(8) We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

(9) Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.

(10) With reference to the attached drawings and with particular reference to FIGS. 1, 2 and 3, a heat exchanger 10 according to the present invention comprises at least a first plate 11 and at least a second plate 12 overlapping and joined together, see FIG. 2.

(11) Once the plates 11 and 12 have been made to overlap and joined together, it is possible to define a perimeter edge 13 of the heat exchanger 10, thus formed by the overlapping perimeter edges of the two plates 11, 12.

(12) The plates 11, 12 have a substantially flat development, with a substantially uniform thickness. The plates 11, 12 can also have the same or different thickness.

(13) The plates 11, 12 can be of any shape whatsoever, but preferably are square or rectangular in shape.

(14) The plates 11, 12 are made of a material having a low thermal resistance, for example aluminum or an aluminum alloy. In particular, the choice of material also depends on the compatibility and chemical resistance to contact with various heat-carrier fluids, or better, as a function of the resistance to corrosion with respect to the latter.

(15) On the plates 11 and 12, as explained below and by means of Roll-Bonding technology, a circuit 14 is made for the passage of a heat-carrier fluid.

(16) The shape and configuration of the circuit 14 is defined in the design phase and therefore the circuit 14 comprises one or more channels 15 which branch out and/or join in various ways, as can be seen in FIG. 1.

(17) Furthermore, it is possible to provide at least one channelized area 16 for heat exchange, in which branching points 17 are provided in which the two plates 11 and 12 are reciprocally joined.

(18) As can be seen from FIG. 1, with the term channelized area we mean a sufficiently large heat exchange surface of the present heat exchanger 10, for example such that one of the sizes that define it is substantially equal to or slightly smaller than one of the two sides of the heat exchanger 10, for example the short side.

(19) It is also possible to provide that the channels 15 extend in a straight or curved shape and that connection zone 18 are provided.

(20) According to the Roll-Bonding technology, in a first step of producing the heat exchanger 10, on one of the plates 11, 12 a detaching material is deposited, for example by printing, according to the shape and path to be obtained for the circuit 14.

(21) The plates 11, 12 are then made to overlap with in the middle the shape of the circuit 14 in detaching material and subjected to hot rolling. The circuit 14 will comprise at least one channel 15 and possible channelized areas 16 and/or connection zones 18 or other.

(22) An aperture is left on the perimeter edge 13 obtained by overlapping the plates 11, 12 in order to allow the coupling of a device for introducing compressed air, or other fluid under pressure, which deforms at least one of the plates 11, 12 in correspondence with the detaching material. The fluid under pressure, substantially by inflation, produces one or more channels 15 between the plates 11, 12, as a function precisely of the desired shape of the circuit 14.

(23) When the inflation process of the channels 15 is finished, it is possible to cut to size the two plates 11, 12, coupled and provided with a circuit 14, for example by shearing.

(24) Due to what stated above with reference to the elongation of the material during the rolling step, and due to the need to guarantee a certain margin of tolerance, in the state of the art (see FIG. 5 in which the heat exchanger is indicated with 110, while components identical to those of FIG. 1 are indicated with the same reference number) a closing edge 20 of the heat exchange portion is maintained at a certain safety distance from the perimeter edge 13 of the plate. In this case, this distance is indicated with D0 and normally has a value of at least 35-40 mm. This entails a loss of overall efficiency of the exchanger, and the impossibility of bringing the heat exchange in proximity to the perimeter of the plates.

(25) In the solution of the present invention, the circuit 14 is provided with at least one heat exchange portion 19 provided with a closing edge 20 which is made in proximity to the perimeter edge 13 of the heat exchanger 10, that is, at a minimum distance D1 from the perimeter edge 13, see for example FIG. 2, of up to 3-4 mm. During working, the heat exchange portion 19 is intentionally made to exit the trimming perimeter that defines the perimeter edge 13 of the heat exchanger 10; the two edges that make up the aperture between the plates 11, 12 will be closed during the finishing step, for example by welding.

(26) In particular, in producing this type of circuit of the heat exchanger 10, the channelized areas 16 are voluntarily made to exceed the shearing limits, and the edges of the plates 11, 12 which delimit the surface of the heat exchanger 10 are closed together in the finishing step.

(27) In the circuit 14 of FIG. 1, for example, two heat exchange portions 19 are provided located on opposite sides of the perimeter edge 13 of the heat exchanger 10.

(28) It is possible, for example, to provide that a hole 21 for the inlet or outlet of a heat-carrier fluid is made in one of the heat exchange portions 19. In FIG. 1, for example, one heat exchange portion 19 has a hole 21 for the inlet of the heat-carrier fluid into the heat exchanger 10, and the other heat exchange portion 19 has a hole 21 for the outlet of the heat-carrier fluid from the heat exchanger 10.

(29) A tubular element could be connected to the hole 21, positioned orthogonal or variously inclined with respect to the surface of the heat exchanger 10, defined in this example by the upper surface of the plate 11.

(30) The distance D1 that separates the closing edge 20 of the heat exchange portion 19 from the perimeter edge 13 of the heat exchanger 10 is variable between about 3 mm and about 10 mm. The minimum distance can depend on the type of sealing system used.

(31) The heat exchange portion 19 can have a width L1 which can be equal to the width of one of the channels 14, or it can be provided, preferably, with a width greater than the width of the single channel 14. The width L1 is in any case a function of the area to be cooled or heated, located in correspondence with the perimeter edge 13 and therefore the heat exchange portion 19.

(32) In a variant of the heat exchanger 10′, see FIG. 4, it is possible to provide that the heat exchange portion 19′ coincides with an entire heat exchange channelized area. In this variant, the closing edge 20′ extends for a width L2 such as to substantially occupy an entire side of the perimeter edge 13 of the heat exchanger 10. The closing edge 20′ will be obtained in proximity to the perimeter edge 13, that is, at the minimum distance D1 from the perimeter edge 13.

(33) During the design phase, it is possible to provide that, in correspondence with the zones of the circuit 14 where the heat exchange portions 19, 19′ are to be obtained, the detaching material is deposited up to or beyond the perimeter edge 13 of the heat exchanger 10, 10′ so that it is possible to generate, between the plates 11 and 12 and by inflation, the necessary aperture that defines the channelization inside the heat exchange portion 19, 19′.

(34) The closure of the heat exchange portion 19, 19′, and therefore the production of the closing edge 20, 20′, occurs during a finishing step of the heat exchanger 10 following shearing.

(35) This closure, and therefore the production of the closing edge 20, can occur, for example, by bending the perimeter edge 13 of the plates 11, 12, providing that the heat exchange portion 19 is provided with a segment protruding out of the perimeter edge 13 of the heat exchanger 10.

(36) The closing edge 20, 20′ could also be obtained by welding the plates 11, 12 in proximity to the perimeter edge 13, for example with a TIG, MIG, or MAG type welding, or made with LASER.

(37) Another mode to produce the closing edge 20, 20′ of the heat exchange portion 19, 19′ could be by gluing the plates 11, 12 in proximity to the perimeter edge 13 and subsequent shearing, always providing that the heat exchange portion 19, 19′ protrudes by a certain segment from the perimeter edge 13 of the heat exchanger 10, 10′.

(38) In accordance with possible embodiments, the closing edge 20, 20′ can be produced by a combination of welding, bending and/or gluing.

(39) Essentially, therefore, by already providing during the design phase a heat exchange portion 19, 19′ of suitable sizes, then providing at least one strip of detaching material between the two plates 11, 12 that reaches up to or beyond the perimeter edge 13, before the finishing step, it is possible to define in the geometry of the heat exchanger 10 one or more positions in which, regardless of the sliding of the material during rolling, it will be possible to intercept a heat exchange portion, that is, the heat exchange portion 19, 19′.

(40) Advantageously, by providing the heat exchange portions 19, 19′ it will be possible, for example, to define during the design phase the position of a tubular element, for example an orthogonal or inclined connector, to be connected to the hole 21.

(41) In summary, in embodiments of the invention, the present method to produce a heat exchanger 10, 10′ substantially provides: at least one deposition step, to deposit on at least one of two plates 11, 12 a detaching material according to the shape and path of the heat exchange circuit 14 to be obtained; the overlapping and hot rolling of the plates 11, 12 with in the middle the template of the circuit 14 made of detaching material; the introduction of a fluid under pressure from an inflation aperture made on one of the perimeter edges 13 made by overlapping the plates 11, 12 and consequent deformation of at least one of the plates 11, 12 in correspondence with the detaching material, thus obtaining, by inflation, one or more channels 15 and wherein part of one or more channels 15 is made open toward one of the perimeter edges 13, in particular in a different position from the inflation aperture, the closing, in the finishing step, of said part of the one or more channels 15, thus producing a closing edge 20, 20′ located in proximity to the perimeter edge 13 of the heat exchanger, that is, at a minimum distance D1 from the perimeter edge 13 and defining a heat exchange portion 19, 19′.

(42) It is clear that modifications and/or additions of parts may be made to the heat exchanger and to the corresponding production method as described heretofore, without departing from the field and scope of the present invention.

(43) It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of heat exchanger, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

(44) In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.