EP1308687A1 - Tube for plate-like heat exchanger - Google Patents

Abstract

Two plates (4,5) are connected to each other to form a circulation duct (10) having a fluid inlet orifice and a fluid outlet orifice. A partial blocking component keeps the cross-section of the passage between the fluid inlet and outlet orifices constant.

Description

The technical sector of the present invention is that of heat exchangers and more particularly tubes to disruptive plates that equip them. These exchangers are used especially as an evaporator in a system of air conditioning of a motor vehicle or as radiator in the cooling circuit of such a vehicle.

Heat exchangers called plate heat exchangers, in form of I or U, are generally constituted by the assembly of several flat tubes juxtaposing with each other others and connected to each other by an interlayer whose purpose is to promote the thermal exchange. Each of these tubes is formed by the face-to-face assembly of two plates that define thus a circulation conduit in which the fluid passes. This fluid can be a coolant in the case of a evaporator or a coolant in the case of a radiator.

It is known from the state of the art to dispose of disruptors in the fluid circulation duct. These disrupters are often part of the plates forming the tube. The purpose of these disrupters is to create turbulence during the passage of the fluid so, on the one hand to increase the heat exchange between the fluid and the plates and on the other hand to ensure the mechanical strength of the tube bundle of the exchanger.

One of the main disadvantages of this configuration is the creation of acoustic nuisances due to the overspeed of the fluid, nuisances that it is increasingly important to fight given the increasing level of comfort demanded inside of a vehicle.

Another disadvantage of this type of assembly lies in the does not offer good traffic performance and optimum performance considering the provision substantially anarchic disrupters in the prior art.

The purpose of the present invention is therefore to solve the disadvantages described above mainly by arranging the disruptive on the plates so as to maintain a section of passage of the substantially constant fluid in the circuit while retaining the benefits of the turbulence created by these last. It is therefore a question of optimizing the reduction of load losses / favoring heat exchange.

The subject of the invention is therefore a heat exchanger tube traveled by a fluid, intended to promote heat exchange between an external medium and said fluid, formed by at least two plates connected together to define a conduit of circulation whose cross section is a section of passage of said fluid, said circulation duct having a fluid inlet port and a fluid outlet port, characterized in that said tube comprises an occultation means partial circulation duct intended to maintain substantially constant the passage section of said duct between the inlet port and the outlet port.

According to one characteristic of the invention, the tube is in general form of "U" having a base connected to two branches, said branches being separated by a rib of which the end is terminated by a junction, the passage section to keep constant being any of the ones that extends between the rib and a peripheral edge of the U-shaped tube Passing through the partial occultation means.

According to another characteristic of the invention, the shape of the junction is circular with a diameter greater than twice the width of the rib.

According to yet another characteristic of the invention, the peripheral edge has connection areas connecting the two branches at the base of the U-shaped tube, areas being circular in shape and radius allowing keep the passage section constant.

Advantageously, the partial occultation means is defined by the positioning of disrupters with respect to others so that their cross sections cumulative occultation are substantially constant on the the entire length of the circulation duct.

The crossing section is constant when the difference between a minimum passage section and a passage section determined maximum in the circulation duct does not exceed 20 percent.

This means of occultation is also defined by the shape of disruptive to each other in the conduit of circulation.

Advantageously, the disrupters are arranged on at least one of the plates.

Likewise, the disturbers are arranged on at least one plates so that the direction of the axis supporting their larger dimensions is substantially parallel to the flow direction of the fluid.

According to a variant of the invention, the disrupters are present on both plates.

According to another variant of the invention, at least one disruptor of one of the plates is arranged next to at least one disruptor of the other plate.

The disrupters of each plate are arranged opposite facing each other, the directions of their axes supporting their larger dimensions being substantially parallel between them.

According to one characteristic of the invention, the plates are solidarized by the disrupters.

According to another characteristic of the invention, the Disturbants are oval or circular in shape.

According to yet another characteristic of the invention, the disruptors are in the shape of a rhombus, advantageously rounded at its angles.

Disrupters are pyramidal in shape, the basis of the pyramidal shape being common with one of the plates.

Advantageously, a heat exchanger comprises at least a tube defined according to any of the features preceding.

The heat exchanger is a radiator or an evaporator.

A first advantage of the device according to the invention lies in the lowering of noise nuisances of this type exchanger.

Another advantage lies in the optimization of the combination of performance with respect to noise.

Another advantage of the invention lies in the possibility to optimize the internal pressure drop of the tube.

Another advantage is to improve the combination of performance characteristics with respect to mechanical strength.

• la figure 1 est une vue en perspective d'un échangeur de chaleur utilisant le tube selon l'invention,
• la figure 2 est une vue partielle de face d'une des plaques en forme de « U » du tube d'échangeur de chaleur selon l'invention,
• la figure 3 est une vue en coupe longitudinale selon F-F illustrant les deux plaques du tube d'échangeur de chaleur selon l'invention,
• les figures 4, 5, 7, 8 et 9 sont des vues en coupe transversale du tube d'échangeur de chaleur respectivement selon A-A, B-B, C-C, D-D et E-E illustrant la constance des sections de passage tout au long du conduit de circulation.
• la figure 6 est une vue de face d'une plaque mettant en valeur plus particulièrement la base de la forme en « U ».

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below as an indication in relation to drawings in which:

• FIG. 1 is a perspective view of a heat exchanger using the tube according to the invention,
• FIG. 2 is a partial front view of one of the "U" -shaped plates of the heat exchanger tube according to the invention,
• FIG. 3 is a longitudinal sectional view along FF illustrating the two plates of the heat exchanger tube according to the invention,
• Figures 4, 5, 7, 8 and 9 are cross-sectional views of the heat exchanger tube respectively AA, BB, CC, DD and EE illustrating the constancy of the passage sections throughout the flow conduit.
• Figure 6 is a front view of a plate highlighting more particularly the base of the "U" shape.

Figure 1 illustrates the use that can be made of a tube 1 according to the invention mounted here in a heat exchanger 2. The latter may be an evaporator, a radiator or a condenser. In the case represented here, it is a question of evaporator which consists of a multitude of tubes 1. The number of tubes 1 forming the exchanger 2 is a function of a required heat exchange characteristic, this number is represented in this figure for illustrative purposes and not limiting. A fin spacer 6 is installed between each tube 1 so as to optimize the heat exchange.

The tube 1 is generally formed by two plates 4 and 5 arranged against each other. The juxtaposition of several tubes thus formed makes it possible to constitute a heat exchanger, whose purpose is to promote the heat transfer between a interior medium, preferably a fluid 3, and a medium outside 7 which may be for example air. Both plates 4 and 5 are in contact with each other on their edges 8 devices so as to define, with their inner walls 9, a circulation conduit 10. The latter transports the fluid 3 which may be, for example, coolant in the case of a radiator, or a refrigerant in the case of a evaporator or condenser. This duct 10 is characterized by a passage section 11 which corresponds to the surface filled by the fluid at specific locations in the conduit of circulation. This section of passage 11 will be illustrated more details in the description of FIGS. 4, 5, 7, 8, 9.

FIG. 2 shows more precisely a plate of the tube 1 of the heat exchanger 2. This tube comprises a means partial occultation 12 of the circulation duct 10 of in order to keep the passage section 11 constant at all along the circuit which extends from an inlet 13 of the fluid 3 to an outlet 14 of said fluid.

This figure underlines the constitution of the means of occultation partial 12. The plate 4 front view can highlight the positioning of disrupters 15, 16, 17, some by relationship to others and their possible forms. There was represented a disruptive axis 18 illustrating the disruptive positioning on a horizontal plane and an axis 19 by disruptor illustrating its positioning on a plane vertical. The judicious combination of positioning two interferers, for example 15 and 16, on a vertical plane and on a horizontal plane thus allows the partial occultation means 12 thus formed to keep the passage section 11 constant. The positioning of these disrupters is such that they are in staggered, that is to say that the axes 18 of the disrupters are staggered with a constant pitch or not along a vertical axis in the flow direction of the fluid. These disrupters can present all appropriate forms able to limit the speed of a fluid. In particular, these may take a form oval, circular, diamond-shaped or diamond-shaped, rounded to its angles. These disrupters are manufactured, for example, by stamping and may present, inter alia, a form pyramid. The base of the pyramidal form of the disrupters is common with the plate 4 or 5, in particular according to its wall internal 9.

Figure 3 is a sectional view F-F of Figure 2 illustrating a tube 1 according to the invention. The two plates 4 and 5 forming this tube are arranged face to face. We can see on this figure that the disrupter 15, present on the plate 4, is next to another disruptor 15a present on the plate 5. These two disruptors are in contact within the circulation duct 12 and can therefore participate in the mechanical relationship that connects the two plates 4 and 5. That is to say that the latter can be united to one another, for example by welding or brazing, and thus strengthen the tube structure 1.

Of course, these disrupters can be totally in look at each other so that their axes 18 and 19 be confused, but they can also be just partially opposite each other along axis 18 or 19 or a combination of both (not shown).

Disturbators 16 and 16a shown respectively on plate 4 and 5 have a particularity with respect to in the sense that their ends do not touch each other.

In any case, the combination of characteristics of positioning and forms of disrupters described above and the gap that separates at least one from their ends with respect to the opposite wall is a function of the level required acoustic efficiency in the heat exchanger 2. This yield is dependent on the speed of fluid 3 inside of the tube 1, speed made substantially constant by the means Partial occultation 12.

Figures 4 and 5 are illustrations of the constancy of the passage section 11 throughout the course followed by the fluid 3 in the circulation duct 10 of a tube 1 in form "I" or in the straight portions of a shaped tube of "U". Constant section means a difference of the order of 20% between a mini section and a maxi performed anywhere on the tube.

Figure 4 is an illustration of one of these sections 11 viewable during an A-A cut made in Figure 2. We have represented the two plates 4 and 5 joined according to their edges 8. The circulation duct 10 is delimited here by this peripheral edge 8, the inner walls 9 of the two plates 4 and 5, the shape of the disrupters 15 and 15a and, in the case of a tube 1 in the shape of a "U", by a rib 20. This figure shows for illustrative purposes two disrupters 15 and 15a arranged face to face, their ends being in contact. The passage section 11 is shown in the figure by the hatched part.

Figure 5 shows the common elements already referenced in during the description of Figure 4. On the other hand, performed according to B-B in Figure 2 illustrates the progressivity pyramidal disturbers 15, 15a and 17, 17a. Whereas in FIG. 4, the occultation was caused by two disturbers in contact, we are here in the presence of four disturbers either of lesser depth or of pyramid.

The addition of the occultation section of a disruptor with the concealment section of the neighboring disrupter (s) 15a, 16, 16a, 17, 17a must be substantially constant. We means by occultation section the volume encroached in the circulation duct 12 by a disrupter, limiting volume the passage of the fluid 3. This sum deduced from the total section of the circulation duct 10 is then constant whatever the place where a cut is made between the inlet orifice 13 and the outlet port 14. In the case shown on this figure, the passage section 11 of the fluid is illustrated by the hatched part.

Figure 6 is particular to a tube 1 in the form of "U". This form has two branches 24 and 25 interconnected by a base 26. A circulation duct 10 is thus formed. whose inlet port 13 and the outlet port 14 are substantially aligned. Thus the branch 24 of the "U" is separated of the branch 25 by a rib 20. The circulation duct 10 is then delimited by the peripheral edge 8, the walls internal 9 of the two plates 4 and 5, the form of the disrupters and by the rib 20. The latter is finished on the base side 26 by a preferably circular junction. The diameter of this circular junction 21 is greater than twice the width of the rib 20. At the level of the transition between base 26 and the branches 24 and 25, the circulation duct 10 is limited by the peripheral edge 8, it presents a particular shape illustrated by two connecting zones 22 and 23 of circular and radius general shapes allowing keep a constant section. Junction 21, the disturbances and the connection zones 22 and 23 are of the partial occultation means 12. Their combinations of shapes, positioning and dimensions contribute to maintain substantially constant the passage section 11 in the part bottom of tube 1 in the shape of "U". The orientation of disruptors is arranged in such a way that their sections cumulative cross-sections are constant and therefore indirectly the passage section of the circulation duct 10, despite the particularity of this area of the "U" tube. Indeed, in this case some disrupters, for example 27 and 27a, may have an axis supporting their largest non parallel dimensions with the axis of circulation of the fluid.

FIG. 7 is a representation showing the references common elements described in Figures 4 and 5. This figure illustrates a section C-C of FIG. substantially horizontally at the junction 21. The radius of this junction 21, the positioning and / or the shape of the or disrupters create a blocking section that will limit the fluid velocity in this part of the duct circulation 10. The passage section 11 in this part of the duct is illustrated by hatching.

FIG. 8 shows a passage section 11 in a cross section D-D of Figure 2. This section is obscured by the combination of characteristics dimensions of the junction 21, of the connection zone 22 and disturbers 27, 27a and 28, 28a. The disrupters 27 and 27a have their ends in contact so as to create a maximum concealment section. On the other hand, the disturbers 28 and 28a are of lower depth or pyramidal shape, the occultation section is reduced. The sum of the sections of occultation of the interferers 27, 27a, 28, 28a, junctions 21 and connection areas 22 tends to maintain substantially constant the passage section 11. The latter is illustrated in this figure by a hatched area.

Figure 9 is a variant of layout and shape of disturbers 30, 30a and 29, 29a. Indeed, in this cup Vertical according to E-E, disrupters take a shape Circular particularly suitable for this part of the duct 10. Their occultation sections added to that of the junction 21 contribute to prevent the overspeed of the fluid which is at the origin of certain noise nuisances heat exchangers.

The description above is in no way limited to disruptors face to face with their ends in contact. he is of course reminded that these may not be in contact, be arranged along different axes or be arranged on one or the other or both plates 4 or 5 forming the tube 1. The combination of the characteristics of positioning and / or shape of the elements constituting the means of blackout 12 depends on the necessities required heat exchange and the reduction of pollution sound. The occultation means 12 is of course applicable to a heat exchanger tube having a generally "U" shape, but it is easy to apply this means of occultation to I-shaped plates or other forms of conduit of circulation. The tube defined above is particularly adapted to the radiators and evaporator of an installation of air conditioning of a motor vehicle.

Claims (21)

Tube (1) heat exchanger (2) traversed by a fluid (3) for promoting the heat exchange between an external medium (7) and said fluid, formed by at least two plates (4, 5) connected between them to define a circulation duct (10) whose cross section is a passage section (11) of said fluid, said circulation duct having an inlet (13) of the fluid and an outlet orifice (14) of the fluid, characterized in that said tube comprises a partial occultation means (12) of the circulation duct (10) intended to keep the passage section (11) of said duct between the inlet orifice (13) substantially constant and the outlet (14). Tube (1) of heat exchanger according to claim 1, characterized in that said tube is in the general shape of "U" having a base (26) connected to two branches (24, 25), said branches being separated by a rib (20) whose end is terminated by a junction (21), the passage section (11) to be kept constant being any of that which extends between the rib (20) and a peripheral edge (8). ) of the "U" tube passing through the partial occultation means (12). Tube (1) of heat exchanger according to claim 2, characterized in that the shape of the junction (21) is circular with a diameter greater than twice the width of the rib (20). Tube (1) of heat exchanger according to claim 3, characterized in that the peripheral edge (8) has connection areas (22, 23) connecting the two branches (24, 25) to the base (26) of the U-shaped tube, said areas being circular in shape and radius to keep constant the passage section (11). Tube (1) of heat exchanger according to any one of the preceding claims, characterized in that the partial occultation means (12) is defined by the staggered positioning of disturbers (15, 15a, 16, 16a) each other such that their accumulated occultation cross-sections are substantially constant over the entire length of the circulation duct (10). Heat exchanger tube (1) according to one of the preceding claims, characterized in that the passage section (11) is constant when the difference between a minimum passage section and a maximum flow cross section determined in the conduit (10) does not exceed 20 per cent. Tube (1) of heat exchanger according to any one of the preceding claims, characterized in that the partial occultation means (12) is defined by the form of disrupters (15, 15a, 16, 16a), some by compared to others in the traffic lane. Heat exchanger tube (1) according to Claim 7, characterized in that the interferers (15, 15a, 16, 16a) are arranged on at least one of the plates (4) or (5). Heat exchanger tube (1) according to claim 8, characterized in that the interferers (15, 15a, 16, 16a) are arranged on at least one of the plates (4) or (5) so that the direction the axis (19) supporting their largest dimensions is substantially parallel to the direction of flow of the fluid. Tube (1) heat exchanger according to any one of claims 5 to 9, characterized in that the disturbers are present on the two plates (4, 5). Tube (1) heat exchanger according to claim 10, characterized in that at least one disruptor (15) of one of the plates is disposed facing at least one disruptor (15a) of the other plate. Tube (1) of heat exchanger according to claim 11, characterized in that the interferers (15, 15a) of each plate are arranged facing each other, the directions of their axes (18, 19) supporting their larger dimensions being substantially parallel to each other. Tube (1) heat exchanger according to one of claims 10 to 12, characterized in that the plates (4, 5) are secured by the disturbers (15, 15a, 16, 16a). Tube (1) heat exchanger according to any one of claims 5 to 13, characterized in that the disruptors (15, 15a, 16, 16a) are oval. Tube (1) of heat exchanger according to claim 14, characterized in that the disturbers (15, 15a, 16, 16a) are substantially circular in shape. Tube (1) of heat exchanger according to Claim 14, characterized in that the disturbers (15, 15a, 16, 16a) are in the form of a rhombus. Tube (1) of heat exchanger according to claim 16, characterized in that the disturbers (15, 15a, 16, 16a) are in the form of a rhombus rounded at its corners. Heat exchanger tube according to any one of Claims 5 to 17, characterized in that the interferers (15, 15a, 16, 16a) are pyramidal in shape, the base of the pyramidal form being common with one of the plates (4, 5). Heat exchanger characterized in that it comprises at least one tube (1) defined according to any one of the preceding claims. Heat exchanger according to claim 19, characterized in that it is a radiator. Heat exchanger according to claim 20, characterized in that the latter is an evaporator.

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