Plate constituting a heat exchanger and heat exchanger comprising at least one such plate
Patent Information
- Application Number
- EP2023705560
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-02-28
- Filing Date
- 2023-02-16
- Publication Date
- 2025-01-08
AI Technical Summary
Heat exchangers in vehicles often experience micro-leaks during mechanical strength tests, which are difficult to locate due to the invisibility of these failures using tomography tests, necessitating a method to designate a reference rupture zone for enhanced testing.
The design of heat exchanger plates with specifically engineered protuberances that generate localized rupture, featuring frustoconical or other sectioned protrusions to maximize mechanical stress and facilitate rupture detection, allowing for targeted inspection after testing.
This approach enables effective identification of potential rupture points, simplifying post-test analysis and ensuring the heat exchanger's ability to withstand pressure, thereby improving the reliability of mechanical strength tests.
Smart Images
Figure 1.1
Abstract
Description
[0001]Constituent plate of a heat exchanger and heat exchanger comprising at least one such plate The present invention relates to the constituent plates of a heat exchanger. Its subject is such plates and a heat exchanger comprising at least one pair of such plates. In the automotive field, it is common to have to control the temperature of an element, such as an electric motor, a battery, a device for storing calories and / or frigories or the like. For this purpose, the motor vehicle is equipped with an installation which comprises a refrigerant circuit inside which a refrigerant circulates and a heat transfer liquid circuit inside which a heat transfer liquid circulates.The refrigerant circuit comprises a compressor for compressing the refrigerant, a heat exchanger for cooling the refrigerant at constant pressure, an expansion member for allowing expansion of the refrigerant and a heat exchanger which is arranged to allow heat transfer between the refrigerant and the heat transfer fluid. According to other applications, the motor vehicle may also comprise an exchanger to allow heat transfer between two refrigerants at different temperatures, or between two heat transfer fluids at different temperatures. The heat exchanger is an exchanger formed of stacked plates joined together to form a tube delimiting a channel for circulation of the refrigerant or the heat transfer fluid.The plates comprise at least two openings, arranged in a bottom of the plate, for supplying the circulation channel with heat transfer fluid or refrigerant fluid. The circulation channel provides a passage section for the heat transfer fluid or refrigerant fluid which is a surface taken perpendicular to a plane in which the plates extend and perpendicular to a longitudinal elongation axis of the plates. It is known to arrange protrusions inside the circulation channel to disturb a flow of the refrigerant fluid and / or the heat transfer fluid inside the circulation channel. The protrusions result from a deformation, in particular by stamping, of at least one of the plates. Each protrusion comprises a base arranged in the bottom of the plate and a top wall arranged opposite the base. During the validation phases of such a heat exchanger, it is subjected to mechanical strength tests.These tests, such as burst or cycle pressure tests, aim to ensure that the exchanger is capable of withstanding a certain pressure, a pressure beyond which leaks appear. The problem then lies in the location of said leaks. Indeed, for these heat exchangers, this type of failure generally appears in the form of micro-leaks, most often located in the product bundle, i.e. at the level of the circulation channel. Tomography tests to locate these micro-leaks on heat exchangers after mechanical strength tests have not been conclusive because they are not visible. The object of the present invention is therefore to designate a reference rupture zone for mechanical strength tests on a plate heat exchanger comprising protrusions. For this purpose, certain protrusions are specifically designed to generate a localized rupture.More particularly, the invention relates to a fluid circulation channel formed by at least two plates, each of the plates comprising a bottom and a section, the bottom extending in a first plane, the section extending in a plane parallel to and offset from the first plane, the bottom and the section being connected to each other by an intermediate section. Said channel is also characterized in that the bottom of at least one of the plates comprises a first protuberance, said first protuberance being characterized in that it extends from its base, formed in the first plane of the bottom of said plate, towards its top wall, said top wall being in contact with the bottom of the opposite plate and partially opposite the intermediate section of said plate. The term "plane parallel to and offset from the first plane" means a plane offset in a direction perpendicular to the bottom of the plate.According to at least one aspect of the invention, the fluid circulation channel is characterized in that at least one of the plates comprises at least one second protrusion, extending from its base towards a top wall, said top wall being in contact with the bottom of the opposite plate over its entire surface. According to at least one aspect of the invention, the fluid circulation channel is characterized in that the first protrusions and / or the second protrusions are of frustoconical shape. According to at least one aspect of the invention, the fluid circulation channel is characterized in that the top wall of the first protrusions and / or the second protrusions is of circular, rectangular, triangular or chevron section.According to at least one aspect of the invention, the fluid circulation channel is characterized in that the top wall of the first protrusions and / or the second protrusions extends along a plane parallel to the first planes of each of the plates. According to at least one aspect of the invention, the fluid circulation channel is characterized in that the height of the protrusions is taken between the base and the top wall of said protrusion, this height being between 0.3 mm and 2.0 mm, and preferably between 0.5 mm and 1.5 mm, ideally between 0.7 mm and 1.3 mm. According to at least one aspect of the invention, the fluid circulation channel is characterized in that the plates are rectangular in shape. According to at least one aspect of the invention, the fluid circulation channel is characterized in that each of the plates comprises at least one raised edge, said raised edge surrounding the bottom.According to at least one aspect of the invention, the fluid circulation channel is characterized in that the bottom and the raised edge of each of the plates delimit the fluid circulation channel. According to at least one aspect of the invention, the fluid circulation channel is characterized in that the plates comprise two longitudinal raised edges arranged opposite each other and two lateral raised edges arranged opposite each other. The invention also relates to a heat exchanger comprising a stack of plates according to the invention. According to at least one aspect of the invention, the heat exchanger is characterized in that the stack of plates forms an alternation of first channels and second channels, intended respectively for the circulation of a refrigerant fluid and a heat transfer liquid.According to at least one aspect of the invention, the heat exchanger is characterized in that the first planes in which the bottoms of the plates are inscribed are perpendicular to the stacking direction. According to at least one aspect of the invention, the heat exchanger is characterized in that the section of each of the plates is in contact with the bottom of the opposite plate. According to at least one aspect of the invention, the heat exchanger is characterized in that each of the plates comprises at least four openings. According to at least one aspect of the invention, the heat exchanger is characterized in that each of these openings can be triangular, rectangular or circular. According to at least one aspect of the invention, the heat exchanger is characterized in that each of the sections of each of the plates comprises an opening.This has the advantage of producing the maximum mechanical stress during burst or cycle pressure tests and thus favoring a potential rupture on the first protuberance. The control at the end of the tests will consist at least of verifying the behavior of this first protuberance. According to at least one aspect of the invention, the heat exchanger is characterized in that the openings are distributed two by two at each longitudinal end of the plate, and more particularly at each of the corners of the bottom of the plate. This has the advantage of simplifying the control at the end of the tests by making it possible to verify only at least one of the ends of the channel and by facilitating access to the first protuberance.According to at least one aspect of the invention, the heat exchanger is characterized in that two openings are configured to communicate with one of the first circulation paths provided on one side of the bottom and the other two openings are configured to communicate with one of the second circulation paths provided on another side of the bottom. According to at least one aspect of the invention, the heat exchanger is characterized in that the channel has an I-shaped profile. According to at least one other aspect of the invention, the heat exchanger is characterized in that the bottom of the plates comprises a rib arranged so that the channel has a U-shaped profile. According to at least one aspect of the invention, the heat exchanger is characterized in that the protrusions are deformations of the plate. According to at least one aspect of the invention, the heat exchanger is characterized in that the plates are made by stamping.According to at least one aspect of the invention, the heat exchanger is characterized in that the plates are made of a metallic material, for example capable of being stamped to form in particular the protuberances by stamping the plate, the metallic material being chosen from thermally conductive metallic materials, aluminum or aluminum alloy in particular. The invention also relates to an installation intended for the heat treatment for a vehicle of an element, said element being able to be in particular an electric or thermal motor and / or an electrical energy storage battery, said installation comprising at least one heat exchanger according to the invention.Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below for information purposes in relation to drawings in which: - Figure 1 is a schematic view of an installation comprising at least one heat exchanger according to the invention, - Figure 2 is a schematic view of a first heat exchanger participating in the installation shown in Figure 1, - Figure 3 is a partial schematic view of the first heat exchanger illustrated in Figure 2, - Figure 4 is a schematic front view of a plate constituting the first heat exchanger illustrated in Figures 2 and 3. It should first be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention if necessary.In Figure 1, a motor vehicle is equipped with an element 1 that needs to be cooled or heated, for example to optimize its operation. Such an element 1 is in particular an electric or thermal engine intended to at least partially propel the motor vehicle, a battery provided for storing electrical energy, a device for storing calories and / or frigories or the like. For this purpose, the motor vehicle is equipped with an installation 2 which comprises a refrigerant circuit 3 inside which circulates a refrigerant 4, carbon dioxide for example or the like, and a heat transfer liquid circuit 5 inside which circulates a heat transfer liquid 6, glycolated water in particular or the like. The installation 2 comprises at least one heat exchanger 11, 12 according to the present invention.The installation 2 is described below to better understand the present invention but the characteristics of the installation 2 described are in no way restrictive for the heat exchanger 11, 12 of the present invention. In other words, the installation 2 is likely to have distinct structural characteristics and / or different operating methods than those described without the heat exchanger 11, 12 deviating from the rules of the present invention. The refrigerant circuit 3 comprises a compressor 7 for compressing the refrigerant 4, a refrigerant / outside air exchanger 8 for cooling the refrigerant 4 at constant pressure, for example placed on the front of the motor vehicle, an expansion member 9 to allow expansion of the refrigerant 4 and a first heat exchanger 11 which is arranged to allow heat transfer between the refrigerant 4 and the heat transfer liquid 6.The refrigerant circuit 3 comprises a second heat exchanger 12 which is arranged to allow a heat transfer between the refrigerant 4 and an air flow 10, the air flow 10 circulating for example inside a pipe 13 of a ventilation, heating and / or air conditioning system, before being delivered inside a passenger compartment of the motor vehicle. For this purpose, the element 1 is in relation with a heat exchanger 14, the heat exchanger 14 being able to modify a temperature of the element 1, in particular by direct contact provided between the element 1 and the heat exchanger 14, the heat exchanger 14 constituting the heat transfer liquid circuit 5. The heat transfer liquid circuit 5 comprises a pump 15 for circulating the heat transfer liquid 6 inside the heat transfer liquid circuit 5.The heat transfer fluid circuit 5 comprises the first heat exchanger 11 which is also constitutive of the refrigerant circuit 3. The first heat exchanger 11 comprises at least one first circulation path 21 of the refrigerant 4 and at least one second circulation path 22 of the heat transfer fluid 6, the first circulation path 21 and the second circulation path 22 being arranged to allow heat exchange between the refrigerant 4 present inside the first circulation path 21 and the heat transfer fluid 6 present inside the second circulation path 22. Preferably, the first heat exchanger 11 comprises several first circulation paths 21 and several second circulation paths 22. A first circulation path 21 is interposed between two second circulation paths 22, and a second circulation path 22 is interposed between two first circulation paths 21.The first heat exchanger 11 thus comprises an alternation of first circulation paths 21 and second circulation paths 22. Inside the heat transfer fluid circuit 5, the heat transfer fluid 6 circulates from the pump 15 to the first heat exchanger 11, then circulates inside the first heat exchanger 11 by using the second circulation paths 22 to exchange calories with the refrigerant fluid 4 present inside the first circulation paths 21. The heat transfer fluid then circulates in the heat exchanger 14 to exchange calories with the element 1, then returns to the pump 15. Inside the refrigerant fluid circuit 3, the refrigerant fluid 4 circulates from the compressor 7 to the refrigerant fluid / outside air exchanger 8, then to the expansion member 9.According to a first operating mode of the refrigerant circuit 3, the refrigerant 4 then circulates inside the first heat exchanger 11 by taking the first circulation paths 21 inside which the refrigerant 4 exchanges calories with the heat transfer liquid 6 present inside the second circulation paths 22, then returns to the compressor 7. According to a second operating mode of the refrigerant circuit 3, the refrigerant 4 circulates inside the second heat exchanger 12 by taking circulation paths inside which the refrigerant 4 exchanges calories with the air flow 10, then returns to the compressor 7. In Figure 2, the first heat exchanger 11 is generally parallelepipedal and comprises a cheek 100a and a cheek 100b.The cheek 100a is provided with a heat transfer fluid inlet 101 through which the heat transfer fluid 6 enters the first heat exchanger 11. The cheek 100a is also provided with a heat transfer fluid outlet 102 through which the heat transfer fluid 6 is discharged from the first heat exchanger 11. The second circulation paths 22 extend between the heat transfer fluid inlet 101 and the heat transfer fluid outlet 102. The cheek 100a also has a refrigerant inlet 103 through which the refrigerant 4 enters the first heat exchanger 11 and a refrigerant outlet 104 through which the refrigerant 4 is discharged from the first heat exchanger 11. The first circulation paths 21 extend between the refrigerant inlet 103 and the refrigerant outlet 104.In Figure 3, in which the cheek 100b of the first heat exchanger 11 has been removed, the first heat exchanger 11 is a plate exchanger which comprises a plurality of plates 105, such as the plates 105 shown diagrammatically in Figures 4. The plate 105 extends mainly along a longitudinal axis of elongation A1. The plate 105 comprises a bottom 106 and at least one raised edge 108a, 108b, 109a, 109b which surrounds the bottom 106. In other words, the raised edge 108a, 108b, 109a, 109b is provided at the periphery of the bottom 106 and the raised edge 108a, 108b, 109a, 109b surrounds the bottom 106. It is understood that the plate 105 is arranged in a generally rectangular bathtub, the bottom of the bathtub being made up of the bottom 106 and the edges of the bathtub being made up of the raised edge 108a, 108b, 109a, 109b.More particularly, the raised edge 108a, 108b, 109a, 109b comprises two longitudinal raised edges 108a, 108b arranged opposite each other and two lateral raised edges 109a, 109b arranged opposite each other. The plate 105 comprises four openings 110, said openings 110 possibly being triangular. These openings 110 may also be, for example, circular, rectangular. These openings 110 are distributed two by two at each longitudinal end of the plate 105, and more particularly at each of the corners of the bottom 106 of the plate 105. Two of these openings 110 are configured to communicate with one of the first circulation paths 21 provided on one side of the bottom 106 and the other two openings 110 are configured to communicate with one of the second circulation paths 22 provided on another side of the bottom 106.Two of the openings 110 provided at the same longitudinal end of the plate 105 are each surrounded by a section 120, such that these openings 110 surrounded by this section 120 extend in a first plane parallel and offset, in a direction perpendicular to the bottom 106 of the plates 105, relative to a first plane P1 in which the bottom 106 is inscribed. The two other openings 110 located at the other longitudinal end of the plate 105 extend in the first plane P1. The bottom 106 and each of the sections 120 of each of the plates 105 are connected to each other by an intermediate section 119. Two plates 105 are nested one inside the other and in contact with each other at least by means of their raised edges 108a, 108b, 109a, 109b. In other words, two plates 105 are stacked one above the other and provide between them a space which forms the channel 111a, 111b for circulation of the refrigerant fluid 4 or the heat transfer liquid 6.The bottom 106 comprises a rib 113 which is arranged so that the channel 111a, 111b has a U-shaped profile. The rib 113 is parallel to a direction D of elongation of the longitudinal raised edges 108a, 108b, the direction D of elongation of the longitudinal raised edges 108a, 108b being preferentially parallel to the longitudinal axis of elongation A1 of the plate 105. The rib 113 extends between a first longitudinal end 114 and a second longitudinal end 115, the first longitudinal end 114 being in contact with the raised edge 108a, 108b, 109a, 109b, and preferentially in contact with a first lateral raised edge 109a which the raised edge 108a, 108b, 109a comprises, 109b.The second longitudinal end 115 is located at a first non-zero distance D1 from the raised edge 108a, 108b, 109a, 109b, the first distance D1 being taken between the second longitudinal end 115 and the raised edge 108a, 108b, 109a, 109b, measured along the longitudinal elongation axis A1 of the plate 105. These arrangements are such that the channel 111a, 111b is shaped into a U whose branches of the U are parallel to the longitudinal raised edges 108a, 108b of the plate 105 and are separated by the rib 113, and whose base of the U adjoins a second lateral edge 109b which is arranged longitudinally opposite the first lateral edge 109a. In Figure 4, three plates 105 are nested within each other so that the raised edge 108a, 108b, 109a, 109b of one plate 105 is embedded inside the raised edge 108a, 108b, 109a, 109b of the immediately succeeding plate 105.Such a stacking of the plates 105 is also carried out in such a way that the bottoms 106 of the plates 105 are arranged parallel to each other in a distant and stepped superposition of the bottoms 106. The raised edges 108a, 108b, 109a, 109b of two plates 105 embedded in each other are in contact and are intended to be brazed with each other to ensure a seal of the channel 111a, 111b thus formed between two adjacent plates 105. Two adjacent plates 105 are also associated in such a way that the grooves 113 of the two adjacent plates 105 are superimposed on each other. Two plates 105 thus nested one inside the other jointly delimit a tube 123 which channels a circulation of the refrigerant fluid 4 or of the heat transfer liquid 6. In other words, the two plates 105 forming the tube 123 jointly delimit the channel 111a, 111b dedicated to the circulation of the refrigerant fluid 4 or of the heat transfer liquid 6.More particularly, one side of a plate 105 borders the first channel 111a for circulation of the refrigerant fluid 4 and the other side of the same plate 105 borders the second channel 111b for circulation of the heat transfer liquid 6. Thus, the plates 105 are arranged between them so as to alternately configure the channels 111a, 111b for circulation of the refrigerant fluid 4 and the heat transfer liquid 6. Each of the plates 105 is advantageously provided with a plurality of protuberances 112a, 112b. Each of the protrusions 112a, 112b of a plate 105 extends from its base 117, arranged in the first plane P1 of the bottom 106 of said plate 105, towards its top wall 116. The top wall 116 is the wall of the protrusion 112a, 112b which is furthest from the bottom 106. The protrusions 112a, 112b are divided into two categories.Thus, each of the plates 105 comprises at least one first protuberance 112a, characterized in that the top wall 116 of said first protuberance 112a is in contact with the bottom of the opposite plate 105 and partially opposite the intermediate section 119 of said plate 105. Each of the plates 105 comprises a plurality of second protuberances 112b. The top wall 116 of the second protuberances 112b is in contact with the bottom 106 of the opposite plate over its entire surface. The height H of the protuberances is taken between the base 117 of the protuberance 112a, 112b which is formed in the first plane P1 of the bottom 106 and the top wall 116 of said protuberance 112a, 112b. This height being between 0.3 mm and 2.0 mm, and preferably between 0.5 mm and 1.5 mm, ideally between 0.7 mm and 1.3 mm. Each of the plates 105 comprises four openings 110 and each of the sections 120 of each of the plates 105 comprises an opening 110.In addition, each of the sections 120 of each of the plates 105 is in contact with the bottom 106 of the opposite plate 105. The plate 105 is made of a metallic material, capable of being stamped to form in particular the protuberances 112a, 112b and the rib 113 by stamping the plate 105, the metallic material being chosen from thermally conductive metallic materials, aluminum or aluminum alloy in particular.
Claims
CLAIMS 1. Fluid circulation channel (111a, 111b) (4, 6) formed by at least two plates (105), each comprising a bottom (106) and a section (120), the bottom (106) extending in a first plane (P1), the section (120) extending in a plane parallel to and offset from the first plane (P1), the bottom (106) and the section (120) being connected by an intermediate segment (119), the bottom (106) of at least one of the plates (105) comprising a first protrusion (112a), said first protrusion (112a) being characterized in that it extends from its base (117) to its apex wall (116), said apex wall (116) being in contact with the bottom (106) of the opposite plate (105) and partially opposite the segment intermediate (119) of said plate (105). 2.Fluid circulation channel (111a, 111b) for fluid (4, 6) according to the preceding claim, characterized in that at least one of the plates (105) comprises at least one second protrusion (12), extending from its base (117) to a summit wall (116), said summit wall (116) being in contact with the bottom (106) of the opposite plate (105) over its entire surface.
3. Fluid circulation channel (111a, 111b) for fluid (4, 6) according to any one of the preceding claims, characterized in that each of the plates (105) comprises at least one raised edge (108a, 108b, 109a, 109b), said raised edge (108a, 108b, 109a, 109b) surrounding the bottom (106).
4. Fluid circulation channel (111a, 111b) according to the preceding claim, characterized in that the bottom (106) and the raised edge (108a, 108b, 109a, 109b) of each of the plates (105) delimit the fluid circulation channel (111a, 111b) (4, 6).
5. Heat exchanger (11) comprising a stack of plates (105).according to any one of the preceding claims.
6. Heat exchanger (11) according to the preceding claim, characterized in that the stack of plates (105) forms an alternation of first channels (111a) and second channels (111b), intended respectively for the circulation of a refrigerant (4) and a heat transfer fluid (6).
7. Heat exchanger (11) according to any one of the preceding claims, characterized in that the section (120) of each of the plates (105) is in contact with the bottom (106) of the opposite plate (105).
8. Heat exchanger (11) according to the preceding claim, characterized in that each of the plates (105) comprises at least four openings (110).
9. Heat exchanger (11) according to the preceding claim, characterized in that each of the sections (120) of each of the plates (105) comprises an opening (110). 10.Installation (2) intended for the heat treatment for vehicle of an element (1), said element being in particular an electric or thermal motor and / or an electrical energy storage battery, said installation (2) comprising at least one heat exchanger (11) according to any one of claims 5 to 9.