FR2657423A1 - Heat exchanger with elongate plates, in particular oil cooling radiator - Google Patents

Abstract

Head exchanger comprising a stack of elongate plates, each of which is formed by assembling two stamped (drawn) half-plates (10) which define between them a flow channel for a first fluid, each half-plate being a stamped plate including a central part (12), of rectangular general shape, in which two collars (14) and a peripheral assembly rim (16) are formed, which rim is situated in a plane which is offset with respect to the central part and has two long sides (18) and two short sides (20).

Description

Heat exchanger with elongated blades, in particular oil cooling radiator
The invention relates to a heat exchanger with elongated blades which can in particular constitute an oil cooling radiator for an internal combustion engine.

We already know, from AFRES the French addition certificate n ° 71.07767, published under n ° 2.128.125, a heat exchanger of this type which comprises a stack of elongated blades each of which is formed by the assembly of two half stamped blades, delimiting between them a circulation channel for a first fluid and in which each half-blade has two collars adapted to be connected to the two collets of an adjacent half-blade to establish the passage of the first fluid from a blade to another, the blades being spaced two by two to allow the passage of a second fluid and thus achieve a heat exchange between the two fluids.

In the case where such a heat exchanger is used as an oil cooling radiator, the first fluid consists of the oil to be cooled, while the second fluid consists of fresh air.

In this known heat exchanger, each half-blade has two end heads in which the two connection collars are respectively formed. When two half-blades are assembled together to form a blade, they define a hollow body comprising two end collecting chambers, each formed by two opposite heads. The collecting chambers of the same blade communicate with each other by a circulation channel and they communicate with the collecting chambers of the other blades by means of connection collars. This known heat exchanger further comprises, inside each blade, a disturbing element capable of increasing the length of the path of circulation of the first fluid and, consequently, of improving the performance of the heat exchanger.

However, this known heat exchanger has a number of drawbacks.

First of all, the blade end heads must have a particular shape in order to be able to resist the high pressures of the first fluid which circulates in the heat exchanger.

In addition, the disturbing element can only extend in the part of each blade which is between the two end heads, which reduces the effectiveness of this disturbing element.

Furthermore, in this known heat exchanger, it is necessary to provide half-blades of the male type and half-blades of the female type to ensure the assembly of the half-blades and the collars.

It is therefore necessary to have two different tools for a blade of given dimensions, which increases the number of tools to be provided if one wishes to produce a whole range of blades having different dimensions.

In addition, in this known heat exchanger, the collars are connected to each other by interlocking, which creates pressure losses adversely affecting the efficiency of the heat exchanger. Finally, as the collars have come from stamping with the half-blade, they necessarily have a limited height from which it follows that the space or interval comprised between two adjacent blades is necessarily limited and, moreover, not adjustable.

The object of the invention is in particular to remedy the drawbacks mentioned above.

It therefore proposes a blade heat exchanger of the type mentioned in the introduction in which, in accordance with the invention, each half-blade is a stamped plate comprising a central part of generally rectangular shape in which the two collars are formed and a peripheral assembly rim located in a plane offset from the central part and having two long sides and two short sides.

As the collars are connected directly to the central part of the half-blade, it is no longer necessary to provide specific blade heads and the blades are much more resistant to pressure.

Advantageously, each blade internally receives a disturbing element which has a generally rectangular shape having substantially the same dimensions as the central part of the half-blades and which is provided with two passage openings located in alignment with the collars. As the disturbing element covers the entire internal surface of the blade which is subjected to pressure, this blade has better resistance to pressure and better heat exchange efficiency.

According to another characteristic of the invention, each half-blade is obtained from a profiled sheet suitable for constituting the central part and the long sides of the peripheral assembly rim, this sheet then being cut to a chosen length and subjected a forming operation to define the two short sides of the peripheral rim and the two stamped collars, with a spacing chosen between the two collars.

Consequently, starting from a given profile sheet, a whole series of half-blades can be produced which differ from each other simply by the length - and the value of the center distance of the two collars.

In a preferred embodiment of the invention, the half-blades are identical to each other and each comprise two cylindrical collars with circular section of the same diameter. The collars of two adjacent half-blades can then be connected - by a cylindrical ring with circular section fitted around the collars.

Advantageously, each ring is chosen from a set of rings of the same internal diameter but of different length, which makes it possible to adjust the space provided between two adjacent blades.

According to another characteristic of the invention, the heat exchanger comprises intermediate elements of corrugated shape placed respectively in the spaces provided between the blades, which makes it possible to improve the heat exchange and to ensure mechanical strength between the blades.

According to another characteristic of the invention, at least one of the two half-blades placed at the ends of the stack receives a cheek of generally rectangular shape.

Such a cheek contributes to the mechanical strength of the heat exchanger and also makes it possible to fix the heat exchanger on a suitable support or fix accessories on this heat exchanger.

In the description which follows, given solely by way of example, reference is made to the appended drawings, in which - FIG. 1 is a perspective view of a half-blade suitable for forming part of a heat exchanger according to l invention - Figures 2 to 4 show different stages of manufacturing the half-blade of Figure 1; - Figures 5 and 6 show two phases of manufacturing a specific disturbing element to be part of a heat exchanger according to the invention - Figure 7 is an elevational view of a plate heat exchanger according to invention - Figure 8 is a partial sectional view on an enlarged scale along the line Vili-Vili of Figure 7; and - Figure 9 is a sectional view similar to that of Figure 8 in another embodiment of the invention.

 First of all, reference is made to FIG. 1 which shows a half-blade 10 formed from a stamped sheet, for example an aluminum or steel sheet, preferably pressed on its two faces. The half-blade 10 comprises a flat central part 12 of generally rectangular shape in which two cylindrical collars 14 of circular section are formed. These two collars are separated by an inter-axis E in the longitudinal direction of the half-blade 10. The central part 12 is surrounded by a peripheral assembly flange 16 which is located in a plane offset from that of the central part 12 The rim 16 has a generally rectangular outline and has two long sides 18 and two short sides 20.

The collars 14 protrude from the opposite side of the flange 16, that is to say towards the bottom of FIG. 1.

The half-blade 10 is advantageously made from a profiled sheet 22 (Figure 2) obtained by deformation of a flat sheet by means of a knurl 24 and a counter-roll (not shown) of complementary shape. The knurl 24 comprises a central cylindrical part 26 surrounded by two cylindrical flanges 28 coaxial and of larger diameter than the part 26. The profiled sheet 22 includes a bottom 30 and two lateral flanges 32 suitable for respectively forming the central part 12 and the two long sides 18 of the half-blade 10. Using a cutting tool 34 (FIG. 2), a selected length of the profiled sheet 22 is then cut to obtain a section 36 of generally rectangular shape, of length L and of width 1. Then, using two forming tools (not shown), the two short sides 20 of the flange 16 as well as the two collars 14 are formed with the press (FIG. 4). A half-blade 10 similar to that of FIG. 1 is thus obtained, the length L and the inter-axis E of the collars can be adjusted as desired depending on the type of heat exchanger to be manufactured.

As will be seen below, two half-blades 10 can be joined together by their respective edges 16 to form a hollow blade internally. In the hollow space formed in such a blade, a disturbing element 38 is preferably placed as shown in FIG. 5. This element has the general shape of a rectangular plate having substantially the same dimensions as the central part 12 of the half-blade 10. It has, on its two faces, reliefs 40 capable of disturbing the flow of the fluid flowing inside the corresponding blade.

As the disturbing element occupies the entire internal surface of the blade, the latter is more resistant to pressure and the heat exchange efficiency is improved. As shown in FIG. 6, the disturbing element 38 is provided with two passage openings 42, of circular shape, which are separated from each other by the same center distance E as that of the collars 14. Consequently, when the element Ferturbator 38 is placed inside a blade, the openings 42 are in the same alignment as the collars 14.

Referring now to: Figure 7 which shows a heat exchanger 44 comprising a stack of elongated blades 46 each of which is formed by the assembly of two half-blades 10 as described above. The two half-blades of the same pair are joined together by their respective flanges 16, for example by welding or brazing, to form a blade 46 hollow internally and defining a circulation channel for a first fluid. The two collars of a half-blade 10 are connected to the two collars of an adjacent half-blade (forming part of another blade) by means of cylindrical rings 48 (FIGS. 7 and 8) whose internal diameter corresponding to the diameter collar 14). The rings 48 are tightly connected to the collars 14, preferably by brazing. Each of the blades 46 internally defines a flow channel 50 for a first fluid (FIG. 8) and the different channels communicate with each other by the collars 14. From preferably each blade internally receives a disturbing element which has not been shown in FIG. 8 to simplify the drawing. This first fluid performs a heat exchange with a second fluid which passes through the exchanger through the free spaces made respectively between two adjacent blades 46 According to the invention, the rings 48 can be chosen from a set of rings of the same internal diameter but of different height H (FIG. 8) to adjust the space provided between two adjacent blades. It is thus possible to modify the capacities of the heat exchanger, which was not possible with the heat exchangers of the prior art.

The heat exchanger shown in FIG. 7 further comprises intermediate elements 52, of wavy shape, which are placed each time in the free space made between two adjacent blades 46. Each intermediate element has a width substantially equal to that of the blades and a length sufficient to extend between the two rings 48 joining the two blades considered. The orientation of the corrugations allows the passage of the second fluid in a direction perpendicular to that of the plane of Figure 7. These intermediate elements 52 promote the mechanical strength of the assembly and also allow better heat exchange between the two fluids.

As shown in Figure 7, the two half-blades 10, placed at the ends of the stack, receive respectively cheeks 54 and 56 of generally rectangular shape. In the embodiment of Figures 7 and 8, the cheeks 54 and 56 are fixed directly to the corresponding end half-blade. Each of the cheeks, for example the cheek 54 (FIG. 8), has two passage openings 58, of circular shape having an internal diameter greater than the external diameter of the collars 14, the two openings 58 being separated from the same interaxis E as the collars. Thus, the two collars of each of the end plates can pass through these plates and protrude outside. On the external face of the cheek 54 and around the two collars 14 protruding through the plate 54, two plugs 60 are attached. and 62 (FIGS. 7 and 8) which can serve as a closure plug or else as a connection plug.

On the plate 56 and around the collars which project beyond the latter, two plugs are also attached (not shown). For example, the plugs 60 and 62 can be connected respectively to an inlet manifold and to an outlet manifold for the first fluid and the two collars protruding from the plate 56 can be simply closed by closure plugs. In this case, the first fluid enters the heat exchanger 44 through the plug 60 circulates in the channels 50 of the blades 46 and leaves the exchanger through the connection plug 62. The first fluid then undergoes heat exchange with the second fluid which crosses the free spaces formed between the blades.

The stoppers can be closure stoppers ensuring the obturation of a collar of an end half-blade or stoppers having a suitable hole to serve as connection. In this case, these plugs are advantageously provided with an external thread as indicated respectively in 64 and 66 for the plugs 60 and 62.

 Referring now to Figure 9 which shows a heat exchanger 68 of a structure very close to the exchanger 44 described above. The heat exchanger 68 also comprises a stack of blades 46 each formed by the assembly of two half-blades 10. Here again, the collars 14 of the half-blades are connected together by cylindrical rings 48.

The two half-blades placed at the ends of the stack receive cheeks 70 and 72 respectively of generally rectangular shape. In this embodiment, the cheek 70 is fixed to the corresponding end half-blade by means of two cylindrical rings 74 suitable for being embolished on their respective collars 14 while being tightly connected to them and each having an annular flange 76 to which the cheek 70 is fixed, for example by soldering. Likewise, the cheek 72 is fixed to the other end half-blade 10 by two similar rings 74 also having an annular flange 76 The advantage of this variant is that there is each time a free space between the cheek 70 and the corresponding end half-blade and another free space between the cheek 72 and the corresponding half-blade. two spaces can be inserted an intermediate element (not visible in FIG. 9) similar to each of the intermediate elements 52 shown in FIG. 7. In this way, the heat exchange capacities of the exchanger are improved.

Each of the cheeks 70 and 72 may optionally include at least one passage opening aligned with a collar 14 of the corresponding end half-blade. In the example, the cheek 70 has two openings 78 allowing the fixing of two plugs 80 allowing respectively the connection of an intake manifold of the first fluid and an outlet manifold of this same fluid. On the other hand, the plate 72 is full and thus closes the passage openings aligned with the two collars 14 of the other end half-blade.

 It will be understood that the heat exchanger of the invention can be produced in different dimensions and with relatively simple tools. In all cases, we refer to assembling the different components of the exchanger by welding or brazing.

The heat exchanger of 1 invention can be used particularly in the automotive industry for example to cool the lubricating oil of an internal combustion engine or to cool the charge air of a turbo-compressed engine.

Claims (10)

Claims 1. - Heat exchanger comprising a stack of elongated blades (46) each of which is formed by the assembly of two half-blades (10) stamped, delimiting between them a circulation channel (50) for a first fluid and in which each half-blade (10) has two collars (14) adapted to be connected to the two collars of an adjacent half-blade to establish the passage of the first fluid from one blade to another, the blades being spaced two by two to allow the passage of a second fluid, characterized in that each half-blade (10) is a stamped plate comprising a central part (12) of generally rectangular shape, in which the two collars (14) are formed, and a peripheral rim d 'assembly (16) located in a plane offset from the central part and having two long sides (18) and two short sides (20). 2. - Heat exchanger according to claim 1, characterized in that each strip (46) internally receives a disturbing element (38) which has a generally rectangular shape having substantially the same dimensions as the central part (12) of the half-strips (10) and which is provided with two passage openings (42) located in alignment with the collars (14). 3. - Heat exchanger according to one of claims 1 and 2, characterized in that each half-blade (10) is obtained from a profiled sheet (22) suitable for constituting the central part (12) and the long sides (18) of the peripheral assembly flange (16), this sheet being then cut to a chosen length (L) and subjected to a forming operation to define the two short sides (20) of the peripheral flange (16) and the two stamped collars (14), with a center distance (E) chosen between the two collars. 4. - Heat exchanger according to one of claims 1 to 3, characterized in that the half-blades (10) are identical and comprise cylindrical collars (14) with circular section of the same diameter, the collars (14) of two adjacent half-blades being connected by a cylindrical ring (48) of circular section, fitted around the collars (14). 5. - Heat exchanger according to claim 4, characterized in that each ring (48) is chosen from a set of rings of the same internal diameter but of different heights (H) to adjust the space provided between two adjacent blades. 6. - Heat exchanger according to one of claims 1 to 5, characterized in that it comprises intermediate elements (52) of corrugated shape respectively placed in the spaces formed between the blades. 7. - Heat exchanger according to one of claims 1 to 6, characterized in that at least one of the two half-blades (10) placed at the ends of the stack receives a cheek (54,56; 70,72) generally rectangular in shape. 8. - Heat exchanger according to claim 7, characterized in that the cheek (54) is fixed directly on the end half-blade (10) and has two passage openings (58) for the collars of the half-blade.  9. - Heat exchanger according to claim 7, characterized in that the cheek (70, # 2) is fixed to the end half blade by means of two cylindrical rings (74) respectively surrounding the two collars (14 ) of the half-blade and in that said cheek optionally has at least one passage opening (78) aligned with a collar of the end half-blade, an intermediate element (52), of wavy shape, being possibly placed between the end half-blade and the cheek (70,72). 10. - Heat exchanger according to one of claims 7 to 9, characterized in that it further comprises closure or connection plugs (60,62; 80) fixed on the collars (14) of the half-blades end and / or on the cheeks (54,56; 70,72).