Patent Application
20150354899
The invention relates to an exchanger. Although intended more specifically for applications as an internal exchanger of an air conditioning circuit or as an exchanger between a refrigerant and a heat transfer fluid, it may also be utilized more broadly for any type of exchange of heat between two fluids.
Numerous configurations of exchangers defining circulation blades for each of the fluids, between which the exchange of heat is required to take place, are known in this field. Brazed exchangers in which the blades are defined by stacked plates, between which the circulation blades are defined alternately, are particularly well known. The blades for the circulation of fluid are joined together by connection elements discharging in the area of passage openings that are likewise provided in the plates in such a way that each fluid passes from one of its circulation blades to the other without penetrating into the circulation blades of the other fluid. The circulation blades of each of the fluids are thus traversed by the connection elements of the other fluid.
Such a configuration multiplies the brazing zones, in particular in the area of the junction between the connection elements and the passage openings of the neighboring plates. It also multiplies the risks in terms of the sealing between each of the fluid circuits. Specific sealing tests are thus necessary.
Furthermore, the zones of the plates that are equipped with said connection elements contribute not at all or only a little to the exchange of heat. As a result, they increase the cost of the exchanger because of the mass of material employed, yet without improving the efficiency of the thermal exchange.
The object of the invention is to address the aforementioned disadvantages, and in this respect it proposes a heat exchanger, in particular for a refrigerant circulating in a motor vehicle, said exchanger comprising a first unit for circulating a first fluid defining first blades for circulating said first fluid and a second unit for circulating a second fluid defining second blades for circulating said second fluid, said blades being layered in a stacking direction of said blades such that an exchange of heat can take place between said first and second fluids. According to the invention, said units permit the first fluid to circulate while avoiding the second unit, and permit the second fluid to circulate while avoiding the first unit.
In other words, the exchanger is configured in order for the units to be interleaved one inside the other in such a way as to ensure an exchange of heat between the two fluids, but without the first fluid passing though components of the second unit and without the second fluid passing through components of the first unit.
Such a configuration in the form of units makes it possible to avoid causing connection elements between the blades for the circulation of one of the fluids to pass across the blades for the circulation of the other fluid. The zones to be brazed are reduced in this way, and the risks of leakage from one circuit for the circulation of a fluid to the other are limited. The test procedures may be simplified as a result. The zones of circulation blades which serve not at all or very little for the exchange of heat are reduced in addition.
According to different embodiments, which may be taken together or separately:
The invention further relates to an exchanger unit such as the one or the other of the units of the exchanger described above.
Said unit may be utilized as a functional component either in such an exchanger with interleaved units, or in another type of exchanger.
Said unit may thus be equipped with a spacer between said pairs of plates and may serve, in particular, as an evaporator by exchange with a flow of air.
It may also be inserted in a housing, and the invention further relates to another heat exchanger comprising such a heat exchanger unit and a housing for circulating another fluid, said unit being situated in the interior of said housing in order to permit an exchange of heat between the fluid circulating in said unit and said other fluid.
These and other characterizing features of the present invention are illustrated below with reference to the accompanying drawings, in which:
In the following description, identical references are used to designate the same or similar elements.
As illustrated in
Said exchanger comprises a first unit 1 for circulating a first fluid defining first blades 3 for circulating said first fluid and a second unit 2 for circulating a second fluid defining second blades 4 for circulating said second fluid. Said blades 3, 4 are layered in a stacking direction D of said blades, such that exchange of heat can take place between said first and second fluids.
Said units 1, 2 are formed, for example, by a component made of aluminum and/or an aluminum alloy. They can be assembled, for example, by brazing of said components.
In
According to a first illustrative embodiment, said heat exchanger may be an internal exchanger of an air conditioning circuit. In other words, said first and second fluids may be a fluid known as R134a or R1234yf, inter alia, such that the first unit 1 serves for the circulation of the fluid in a first temperature and pressure condition, and the second unit 2 serves for the circulation of the fluid in a second temperature and pressure condition.
In another illustrative embodiment, said exchanger ensures an exchange of heat between said refrigerant and a heat transfer fluid, such as a mixture of water and antifreeze, in particular glycol. According to the nature of the refrigerant fluid, this may then result in the cooling or heating of the heat transfer fluid.
Other applications are still possible, however.
According to the invention, said units 1, 2 permit the first fluid to circulate while avoiding the second unit 2 and permit the second fluid to circulate while avoiding the first unit 1. In other words, the exchanger is configured in order for the units to be interleaved one inside the other, in this case such as two combs, but without the first fluid passing through components of the second unit 2 and without the second fluid passing through components of the first unit 1. It is possible in this way to obtain an exchange of heat between the two fluids while avoiding the more complex flows of the state of the art.
Such interleaving will be more readily appreciated from an examination of
Again making reference to
As illustrated by the arrows 1a, 1b, 1c and 2a, 2b, 2c mentioned above, said blades are configured in this case in order to cause a U-shaped circuit to be made for said fluid between a first 5a, 6a of said collectors and a second 5b, 6b of said collectors of the corresponding unit. The first 5a of the collectors of the first unit 1 thus constitute an inlet collector for the first fluid, while the second 5b of the collectors of said first unit 1 constitute an outlet collector for said first fluid. Likewise, the first 6a of the collectors of the second unit 2 constitutes an inlet collector for the second fluid, while the second 6b of the collectors of said second unit 2 constitutes an outlet collector for said second fluid. In other words, the first fluid circulates in the first unit 1 by being distributed by the inlet collector 5a of said first unit 1 in the blades 3 of said first unit 1, where it follows the U-shaped circuit 1a, 1b, 1c mentioned above before subsequently penetrating into the corresponding outlet collector 5b. Likewise, the second fluid circulates in the second unit 2 by being distributed by the inlet collector 6a of said second unit 2 in the blades 4 of said second unit 2, where it follows the U-shaped circuit 2a, 2b, 2c mentioned above before subsequently penetrating into the corresponding outlet collector 6b. The circulation of the first fluid in the blades 3 of said first unit 1 takes place co-currently with the circulation of the second fluid in the blades 4 of said second unit 2.
In a variant embodiment (not depicted here), the circulation of the first fluid in the blades 3 of said first unit 1 advantageously takes place contra-currently with the circulation of the second fluid in the blades 4 of said second unit 2.
For the compactness of the exchanger, the collectors 5a, 5b of the first unit 1 are situated, for example, facing a longitudinal end edge 10 of the blades of the second unit 2, opposite the longitudinal end edge 8 of the blades 2 of the second units 2, in the area of which said collectors 6a, 6b of the second unit 2 are present. Either individually or in combination, the collectors 6a, 6b of the second unit 2 are situated facing a longitudinal end edge 9 of the blades 3 of the first unit 1, opposite the longitudinal end edge 7 of the blades 3 of the first unit 1, in the area of which said collectors 5a, 5b of the first unit 1 are present.
In other words, said units 1, 2 are mounted head-to-tail. Still in other words, the blades 3, 4 of each of said units 1, 2 are offset in relation to the blades 3, 4 of the other of said units 1, 2 in a direction that is orthogonal to said stacking direction D.
Said units 1, 2 in this case comprise plates 11, 12, stacked in said stacking direction, said plates being paired in order to define said blades 3, 4 and said circuits 1a, 1b, 1c, 2a, 2b, 2c of circulation for each of the fluids. According to other embodiments, said blades may be defined by extruded tubes, bent tubes or any other means permitting the guiding of a fluid.
The pairs of plates 11 for the first fluid exhibit a part 13 protruding from the pairs of plates 12 for the second fluid, in planes that are orthogonal to said stacking direction in such a way as to be able to free up a zone of said plates, referred to as header plates, for receiving said collectors 5a, 5b of said first unit 1. Likewise, the pairs of plates 12 for the second fluid exhibit a part 14 protruding from the pairs of plates 11 for the first fluid, in planes that are orthogonal to said stacking direction in such a way as to be able to free up a zone of said plates, referred to as header plates, for receiving said collectors 6a, 6b of said second unit 2.
In other words, said pairs of plates 11 for the first fluid are connected to one another without passing through the pairs of plates 12 for the second fluid, and conversely. In other words, said pairs of plates 11 of the first unit 1 are offset in relation to the pairs of plates 12 of the second unit 2, in said longitudinal direction, and conversely.
Said pairs of plates 11, 12 are advantageously identical in the same unit, except perhaps for the one or more pairs of plates including a terminating plate of the stack, as will be described in more detail below.
Said exchanger comprises fluid connections 15a, 15b, 16a, 16b between the plates 11, 12 of the pairs of plates for the same fluid, situated in the area of said header plates 13, 14, in such a way as to form said collectors 5a, 5b, 6a, 6b. According to the invention, said connections 15a, 15b, 16a, 16b for one of the fluids are situated externally to the pairs of plates 11, 12 for the other fluid.
Said fluid connections 15a, 15b, 16a, 16b comprise, for example, stamped end fittings emerging from said plates 11, 12. Said stamped end fittings 15a, 15b of the plates 11 of the first unit 1 in this case come into contact with the stamped end fittings 15a, 15b of the plate 11 facing the neighboring pair of plates 11 of said first unit 1. Likewise, said stamped end fittings 16a, 16b of the plates 12 of the second unit 2 in this case come into contact with the stamped end fittings 16a, 16b of the plate 12 facing the neighboring pair of plates 12 of said second unit 1. Said stamped end fittings are provided with fluid passage openings. Said stamped end fittings 15a, 15b, 16a, 16b in this way bring about the circulation of fluid from one pair of plates to the other, in the same unit. Said stamped end fittings 15a, 15b, 16a, 16b of the same collector 5a, 5b, 6a, 6b are situated in this case in the axial extension one from the other in such a way as to ensure that said collectors are substantially rectilinear. According to the invention, the stamped end fittings of the pairs of plates for the circulation of the first fluid and the stamped end fittings of the pairs of plates for the circulation of the second fluid are situated at two opposite longitudinal extremities of the assembly formed by the two units 1, 2.
Said plates 11, 12 comprise a longitudinal end edge 17, 18, referred to as the distal edge, opposite an opposing longitudinal end edge 19, 20 of said plates, in the area of which said fluid connections 15a, 15b, 16a, 16b are situated. Said distal edge 17, 18 of the plates 11, 12 for one of the fluids is situated between two facing plates 11, 12 of two neighboring pairs of plates for the circulation of the other fluid.
Said distal edge 17, 18 of the plates 11, 12 of one of the units 1, 2 is in proximity to said fluid connections 15a, 15b, 16a, 16b of the other unit. In order to ensure good mechanical stability, said distal edge 17, 18 may include a part of the contour of said fluid connections 15a, 15b, 16a, 16b.
As can be appreciated more readily from
Each of said pairs of plates 11, 12 comprises a conduit for the U-shaped circulation of the corresponding fluid, between a first of said collectors 5a, 6a permitting the introduction of said fluid into said conduit, and a second of said collectors 5b, 6b permitting the exit of said fluid from said conduit.
Said blades 11, 12 may comprise a baffle 27, 28 for the flow of the first and/or of the second fluid. In this case, said baffles define longitudinal channels for the circulation of the first and/or of the second fluid.
According to a variant that is not illustrated here, the desired U-shaped circulation is obtained by a stamped form of the base of the plates such as a partial central rib starting from the longitudinal end edges provided with the connecting stamped end fittings.
According to another variant, corresponding to the illustrated exchanger, the inlet collectors 5a, 6a discharge facing towards first parts of channels of the baffles 27, 28, while the outlet collectors discharge facing towards a second part of the channels separated from said first part of the channels 29, 30 by one or a plurality of central channels 29, 30. In addition, said plates 11, 12 comprise blocking stamped end fittings 31, 32, between the connecting stamped end fittings 15a, 15b, 16a, 16b, closing said one or more central channels 29, 30 at one of their longitudinal ends.
Said baffles 27, 28 are advantageously shorter than the base 21, 22 of said plates 11, 12 in order to define a half-turn zone for the fluids in each of the pairs of plates.
Referring once again to
The upper terminating plate 12b, in the given orientation in relation to the exchanger in this figure, comprises a protruding part 34 provided with openings, although not visible here, for the passage of the first fluid. Said openings enter into correspondence with the collectors 5a, 5b of the first unit 1. Said upper terminating plate 12b may, furthermore, exhibit openings, similarly not visible here, for the passage of the second fluid towards the corresponding collectors 6a, 6b. Said exchanger in this case comprises one or more connecting flanges 36, 38 for the one and the other of the fluids, subject to said terminating plate 12b in the area of said passage openings. In other words, said second unit 2 in this case comprises not only the one or more connecting flanges 38 for the second fluid, but also the connecting flange 36 for the first fluid.
According to a variant corresponding to the units illustrated in
In the one and/or the other of these embodiments, the lower terminating plate 12b, which is still in the orientation depicted in
As illustrated in
As will be appreciated from what has been stated previously, said one or more units are configured in such a way as to be capable of being inserted into a unit of the same configuration, with or without the same height of the blades 3, 4, by exhibiting a space 101, 102, open between said pairs of blades 3, 4, in the area of the longitudinal end edges 7, 8 of said blades.
Said units 1, 2 may be utilized according to the interleaved configuration already described or in other configurations, for example in the form, not illustrated here, of an exchanger comprising a housing for circulating another fluid and such a unit, positioned inside said housing, in such a way as to benefit from an exchange of heat between said other fluid and that circulating in said unit.
As illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 1262627 | Dec 2012 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2013/076396 | 12/12/2013 | WO | 00 |
