FR3086046A1 - PHASE CHANGE MATERIAL TANK HEAT EXCHANGER - Google Patents

Abstract

The present invention relates to a heat exchanger (1) comprising a bundle of tubes (10, 10 ') comprising a stack of tubes (10,10') parallel to each other and inside which is intended to circulate a first heat transfer fluid between two collecting ends (13) and between which is intended to circulate a second heat transfer fluid, said bundle of tubes (10, 10 ′) comprising at least one reservoir (12) of phase change material delimited by at least one reservoir plate (120) attached to the external surface of at least one reservoir tube (10), the bundle of tubes (10, 10 ') comprising a filling conduit (15) passing through the stack of tubes (10, 10' ) in a direction parallel to the plane defined by the bundle of tubes (10, 10 ') and fluidly connecting the reservoir (s) (12) with a common filling orifice (1110) opening into a first end of the filling conduit (15) .

Description

Phase change material tank heat exchanger

The present invention relates to heat exchangers and more specifically heat exchangers comprising a phase change material, in particular in the field of thermal management in a motor vehicle.

In motor vehicles, it is known to implement an air conditioning device making it possible to regulate the temperature of the passenger compartment of the vehicle.

More specifically, these air conditioning devices use a heat exchanger, for example an evaporator, such as that shown in FIG. 1.

Such a heat exchanger 1 comprises a bundle of tubes 10 formed of a stack of tubes 10. Interleaves 11 are generally placed between two consecutive tubes 10. This bundle of tubes 10 allows a heat exchange between a first heat transfer fluid circulating in the tubes 10 and a second heat transfer fluid, generally a flow of air passing between the tubes (and more precisely through the spacers).

For vehicles fitted with an automatic engine stop system during short stops, in particular, a function has been developed which allows, when the vehicle engine is stopped and no longer drives the start-up compressor. circulation of the heat-transfer fluid, to maintain the cooling of the passenger compartment of the vehicle, thus improving the comfort of the passengers of the motor vehicle.

To do this, the heat exchanger 1 implements one or more tanks of phase change material 12 capable of storing cold when the engine of the motor vehicle is running and then restoring it to the air flow passing through the heat exchanger 1 so as to cool it, for a limited period, when the vehicle engine is stopped.

A heat exchanger 1 of this type, partially illustrated in FIG. 2, comprises at least one reservoir plate 120 which, after brazing with an external face of a tube 10 of the heat exchange bundle, forms a reservoir 12 filled with material phase change.

It will be noted that, in a conventional manner, the tube 10 is obtained by brazing two plates of tube 10A between which an internal insert 103 is placed (FIG. 2).

The reservoir 12 of phase change material is thus in thermal contact with an external face of the tube 10, the reservoir being delimited by the reservoir plate 120 and an opposite surface corresponding to an external face of the tube 10.

Each reservoir 12 of phase change material includes a filling tube for injecting phase change material into the reservoir 12.

As a general rule, a filling member is added to the reservoir 12 in order to allow it to be filled with phase change material. This filling member may in particular be a conduit comprising one or more orifices which have just been placed and fixed opposite openings arranged on the reservoir plate 120. Such filling members are not necessarily adapted because they represent a separate part which has a production cost and the placement of which may be faulty, causing difficulties in filling the tank. In addition, it is necessary to fill each tank individually, which can increase manufacturing time, handling errors and therefore costs.

One of the aims of the present invention is to at least partially remedy the drawbacks of the prior art and to propose a heat exchanger with phase change material with an improved filling member.

The present invention therefore relates to a heat exchanger comprising a bundle of tubes comprising a stack of tubes parallel to each other and inside which is intended to circulate a first heat transfer fluid between two collecting ends and between which is intended to circulate a second heat transfer fluid, said bundle of tubes comprising at least one reservoir of phase change material delimited by at least one reservoir plate attached to the external surface of at least one reservoir tube, the bundle of tubes comprising a filling conduit passing through l stack of tubes in a direction parallel to the plane defined by the bundle of tubes and fluidly connecting the reservoir or reservoirs with a common filling orifice opening into a first end of the filling conduit.

According to one aspect of the invention, the tube bundle comprises a first and a second end plate arranged on either side of the stack of tubes, the first end plate comprising the filling orifice, the second end plate obstructing a second end of said filling duct.

According to another aspect of the invention, the filling orifice of the first end plate is blocked by a closure device.

According to another aspect of the invention, the filling duct is arranged at one of the collecting ends.

According to another aspect of the invention, the collecting end comprising the filling duct is that intended to be on the upper part of said heat exchanger.

According to another aspect of the invention, the tubes comprise two stamped plates and assembled together in a sealed manner so as to form, after assembly, at least one circulation channel in which is intended to circulate the first heat transfer fluid, the reservoir being formed by joining at least one reservoir plate on a first plate of a reservoir tube, said first plate comprising a first orifice opening into said reservoir, said reservoir tube comprising a second plate comprising a hollow protrusion extending towards the exterior of said reservoir tube and also comprising a second opening orifice, the other tubes comprising two second plates assembled to one another, the reservoir plate comprising a third opening orifice and coming opposite the second orifice of the hollow protrusion d '' a second plate of the adjacent tube, the first, second and third ori fices as well as the various hollow growths being aligned and in contact so as to form the filling duct.

This filling conduit thus makes it possible to fill the tanks from the same filling orifice. Furthermore, the fact that the filling conduit crosses the stack of tubes in a direction relatively parallel to the plane defined by the bundle of tubes, the heat exchanger does not comprise a filling member projecting from one of these external faces.

According to another aspect of the invention, the hollow growths are produced by stamping.

According to another aspect of the invention, the hollow growths have a cylindrical shape.

According to another aspect of the invention, the second end plate is a second plate whose hollow protuberance has no second orifice.

According to another aspect of the invention, the elements forming the filling duct are fixed to each other by brazing.

Other characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and nonlimiting example, and of the appended drawings among which:

• Figure 1 shows a schematic perspective representation of a bundle of tubes of a phase change material tank exchanger according to the prior art, • Figure 2 shows a schematic sectional view of a material tank to phase change of Figure 1, • Figure 3 shows a schematic perspective representation of one end of a heat exchanger according to the invention, • Figure 4 shows a schematic sectional view of a material tank phase change, • Figure 5 shows a schematic exploded perspective view of the heat exchanger of Figure 3, • Figure 6 shows a schematic perspective view in section of the heat exchanger of Figure 3 .

In the various figures, identical elements have the same reference numbers.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the characteristics apply only to a single embodiment. Simple features of different embodiments can also be combined to provide other embodiments.

In the present description, it is possible to index certain elements or parameters, such as for example first element or second element as well as first parameter and second parameter or even first criterion and second criterion etc. In this case, it is a simple indexing to differentiate and name elements or parameters or criteria that are similar but not identical. This indexing does not imply a priority of an element, parameter or criterion over another and one can easily interchange such names without departing from the scope of this description. This indexing does not imply an order in time for example to assess this or that criterion.

The embodiment described below is that of a heat exchanger 1 intended to be placed in a ventilation and air conditioning heating device as an evaporator within an air conditioning circuit. This evaporator is especially intended for heat exchange between an air flow and a refrigerant fluid circulating in the air conditioning circuit of the motor vehicle.

It goes without saying that the invention also covers a condenser, a radiator or any other heat exchanger, whatever the heat transfer fluid passing through it.

The heat exchanger 1 according to the invention conventionally comprises a bundle of tubes 10, 10 ′ formed by a parallel stack of tubes 10, 10 ′ and external tabs 11 in a longitudinal stacking direction (visible on Figure 3).

Within the tubes 10, 10 ’is intended to circulate a first heat transfer fluid, in particular the refrigerant fluid of the air conditioning circuit in the case of an evaporator. This first heat transfer fluid circulates between the ends 13 of the tubes 10. These ends 13 can form collectors or water boxes as illustrated in FIG. 3.

The spacers 11, which are louvered or not, are placed between two consecutive tubes 10, 10 ′ and make it possible to increase the heat exchange surface between a second heat transfer fluid, for example an air flow, passing between the tubes 10, 10 'and the first heat transfer fluid circulating in the tubes 10, 10'.

In known manner and as illustrated by FIG. 4, the tubes 10, 10 ′ comprise two plates 10A, 10A ′, which are stamped and brazed to each other and between which may be disposed an internal disturbance 103 taking the form of a corrugated sheet.

More specifically, the plates 10A, 10A 'are stamped and assembled together in a leaktight manner so as to form, after assembly, two adjacent conduits 513, 514, inside which the first heat transfer fluid circulates.

On one of these tubes, called reservoir tube 10, is assembled a reservoir plate 120 in order to form a reservoir 12. The reservoir plate 120 is attached to another tube 10, 10 ’.

In this embodiment, the reservoir 12 is formed on the one hand by a reservoir plate 120 and on the other hand by an opposite surface, which is here constituted by an external face of the reservoir tube 10 (in this case of the outer face of plate 10A).

Thus, the phase change material stored in the reservoir 12 is in direct contact with the external face of the reservoir tube 10, which facilitates and improves the heat exchanges between the first heat transfer fluid circulating in the reservoir tube 10 and the change material phase stored in the tank 12.

The tank plate 120 may in particular have a plurality of bosses which are distributed over its entire surface. The bosses of the tank plate 120 coupled to the tank tube 10 are tangent or flush with the external face of another adjacent tube 10, 10 ’(not shown). Passages are thus delimited outside the reservoir 12 of phase change material so that the second heat transfer fluid can circulate between the reservoir plate 120 and the external face of the other tube 10, 10 ′ adjacent to the reservoir tube 10 This optimizes the heat exchanges between the first heat transfer fluid and the second heat transfer fluid.

One or more spacers 11 are replaced by a reservoir 12 of phase change material. In the case of an evaporator, this phase change material is capable of storing cold when the motor vehicle engine is running and then returning it, for a limited period, to the air passing through the evaporator when the engine of the vehicle is stopped.

The plates 10A, 10A ’of tube 10, 10’, the tank plates 120, and the spacers 11 are preferably made of metal, for example aluminum alloy or the like. This allows them to be attached to each other in the same soldering step.

In another variant not shown, the reservoir 12 of phase change material is not formed from a reservoir plate 120 and from an opposite surface constituted by an external face of a reservoir tube 10.

In this variant, the reservoir 12 is formed by a first reservoir plate 120 and an opposite surface, which here is constituted by a second reservoir plate 120. In this case, the first reservoir plate 120 is in contact with a tube 10 while the second reservoir plate 120 is in contact with a reservoir tube 10.

The first and second tank plates 120 are essentially identical and are preferably symmetrical with respect to their joint plane.

As shown in more detail in FIGS. 3, 5 and 6, the tube bundle 10, 10 ′ comprises a filling duct 15. This filling duct 15 crosses the stack of tubes 10, 10 ′ in a direction relatively parallel to that of the bundle of tubes 10, 10 '. This filling conduit fluidly connects the reservoir (s) 12 with a common filling orifice 1110 opening into a first end of the filling conduit 15.

This filling duct 15 thus makes it possible to fill the reservoirs 12 from the same filling orifice. In the example illustrated in Figures 3, 5 and 6, the heat exchanger 1 only has three tubes 10, 10 'with a single tank 12, but it may of course be possible to imagine a heat exchanger 1 comprising more tubes 10, 10 'and several tanks 12.

In addition, because the filling conduit 15 crosses the stack of tubes 10, 10 ′ in a direction relatively parallel to the plane defined by the bundle of tubes 10, 10 ′, the heat exchanger 1 does not comprise any member filling projecting on one of these external faces.

The tube bundle 10, 10 ’can in particular comprise a first 111 and a second end plate 112 arranged on either side of the stack of tubes 10, 10’. The first end plate 111 may more particularly comprise the filling orifice 1110 (visible in FIGS. 5 and 6). The second end plate 112 can obstruct a second end of said filling duct 15.

The filling orifice 1110 of the first end plate 111 is blocked by a closure device 40 (visible in FIG. 6) after filling of the reservoir (s) 12. This closure device can for example be an inserted rivet and riveted in the filling hole 1110.

Still as shown in FIGS. 3, 5 and 6, the filling duct 15 can in particular be arranged at one of the collecting ends 13 of the heat exchanger 1. More precisely, the collecting end 13 intended to be on the upper part of said heat exchanger 1. Thus, during filling of the tanks 12, the phase change material can flow by gravity into the tanks 12 facilitating their filling.

The filling duct 15 can be formed by the plates 10A, 10A ’themselves. For this, the reservoir tube or tubes 10 can be formed by a first plate 10A and a second plate 10A ’. The first plate 10A of the reservoir tube (s) 10 may in particular comprise a first orifice 1010 opening into the reservoir 12. The second plate 10A 'may in turn comprise a hollow protrusion 1020 extending towards the outside of said reservoir tube 10 and comprising also a second opening 1022 opening.

This hollow protuberance 1020 can in particular have a cylindrical shape. It is however quite possible to imagine other forms for this hollow growth 1020.

The height of this hollow protuberance 1020 is of the order of half the distance between two plates 10A, 10A so that the hollow protuberances 1020 of two adjacent second plates are in contact with one another at their apexes. The second orifice 1022 is made on said vertex so that they are opposite one another.

This hollow protuberance 1020 can in particular be produced by stamping, more particularly during the step of manufacturing the second plate 10A ’.

The other tubes 10 ’may in turn comprise two second plates 10A’ joined together, both comprising a hollow protrusion 1020 extending towards the outside of said tube 10 ’and also comprising a second opening 1022 opening out.

The reservoir plate 120 may comprise a third orifice 1203 opening out and coming opposite the second orifice 1022 of the hollow protrusion 1020 of a second plate 10A ’of the adjacent tube 10, 10’. At this third orifice 1203, the reservoir plate 120 is in contact with the top of the hollow protrusion 1020 of the adjacent second plate 10A.

The first 1010, second 1022 and third 1203 orifices as well as the various hollow protrusions 1020 are aligned and in contact so as to form the filling duct 15.

This structure of the first 10A and second 10A ’plates as well as of the reservoir plate 120 and makes it possible to form the filling duct 15 during the manufacture of the tube bundle 10, 10’ by simple assembly and brazing. This does not require additional steps or the use of a dedicated part which helps limit costs.

According to the example illustrated in Figures 3, 5 and 6, the second end plate 112 obstructing the second end of the filling duct 15 is a second plate 10A 'placed at the end of the stack of tubes 10, 10' and whose hollow protrusion 1020 has no second orifice 1022. It is however quite possible to imagine an alternative embodiment in which the second end of the filling duct 15 is obstructed by other means, for example a device shutter or a plate facing the second orifice 1020.

Thus, it is clear that the heat exchanger 1 due to its filling duct 15 allows filling of all of the tanks 12 from a single point. In addition, this filling conduit 15 makes it possible not to use an attached element projecting from the heat exchanger 1 for each tank 12. The filling conduit 15 can also be formed by elements coming from the material with the plates 10A,

10A 'forming the tubes 10, 10' which limits handling errors and facilitates the manufacturing process.

Claims (10)

1. Heat exchanger (1) comprising a bundle of tubes (10, 10 ') comprising a stack of tubes (10,10') parallel to each other and inside which is intended to circulate a first heat transfer fluid between two collecting ends (13) and between which is intended to circulate a second heat transfer fluid, said bundle of tubes (10, 10 ′) comprising at least one reservoir (12) of phase change material delimited by at least one reservoir plate ( 120) attached to the external surface of at least one reservoir tube (10), characterized in that the bundle of tubes (10, 10 ') comprises a filling duct (15) passing through the stack of tubes (10, 10 ') in a direction parallel to the plane defined by the bundle of tubes (10, 10') and fluidly connecting the reservoir (s) (12) with a common filling orifice (1110) opening into a first end of the filling conduit (15 ). 2. Heat exchanger (1) according to the preceding claim, characterized in that the tube bundle (10, 10 ') comprises a first (111) and a second end plate (112) arranged on either side of the stack of tubes (10, 10 '), the first end plate (111) comprising the filling orifice (1110), the second end plate (112) obstructing a second end of said filling duct ( 15). 3. Heat exchanger (1) according to the preceding claim, characterized in that the filling orifice (1110) of the first end plate (111) is blocked by a closure device (40). 4. Heat exchanger (1) according to any one of the preceding claims, characterized in that the filling duct (15) is arranged at one of the collecting ends (13). 5. Heat exchanger (1) according to the preceding claim, characterized in that the collecting end (13) comprising the filling duct (15) is that intended to be on the upper part of said heat exchanger (1). 6. Heat exchanger (1) according to any one of the preceding claims, characterized in that the tubes (10, 10 ') comprise two plates (10A, 10A',) stamped and assembled together in leaktight manner so as to forming, after assembly, at least one circulation channel (513, 514) in which is intended to circulate the first heat transfer fluid, the reservoir (12) being formed by joining at least one reservoir plate (120) on a first plate (10A) of a reservoir tube (10), said first plate (10A) comprising a first orifice (1010) opening into said reservoir (12), said reservoir tube (10) comprising a second plate (10A ') comprising a hollow projection (1020) extending towards the outside of said reservoir tube (10) and also comprising a second orifice (1022) opening out, the other tubes (10 ') comprising two second plates (10A') assembled one at a the other, the reserve plate r (120) comprising a third orifice (1203) opening out and coming opposite the second orifice (1022) of the hollow projection (1020) of a second plate (10A ') of the adjacent tube (10, 10'), the first (1010), second (1022) and third (1203) orifices as well as the various hollow protrusions (1020) being aligned and in contact so as to form the filling duct (15). 7. Heat exchanger (1) according to the preceding claim, characterized in that the hollow protuberances (1020) are produced by stamping. 8. Heat exchanger (1) according to any one of claims 6 or 7, characterized in that the hollow protrusions (1020) have a cylindrical shape. 9. Heat exchanger (1) according to any one of claims 6 to 8 in combination with claim 2, characterized in that the second end plate (112) is a second plate (10A ') whose projection hollow (1020) 5 has no second orifice (1022). 10. Heat exchanger (1) according to any one of claims 6 or 7, characterized in that the elements forming the filling duct (15) are fixed to each other by brazing.