Enthalpy exchanger including stacked networks and selectively permeable membranes
10281162 ยท 2019-05-07
Assignee
Inventors
Cpc classification
Y02B30/56
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F24F2003/1435
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F12/006
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D9/0037
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D2021/0033
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D2021/0035
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F3/147
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F28D17/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F3/147
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D21/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A dual air flow exchanger, allowing a heat transfer and humidity transfer between two air flows, and including a plurality of first and second air circulation networks separated by membranes permeable to water vapor and impermeable to air and to liquid water, each of the first and second networks including cells each defined by a wall including openings for passage of air, the cell wall including two opposing edges at which same is open in a direction of stacking. For at least one of the first networks, at least one of the two opposing edges of each cell wall defines a hollow open in a direction of the second directly consecutive air circulation network, the hollows receiving a part of the second network.
Claims
1. A dual air flow exchanger, allowing for a heat transfer and a humidity transfer between two air flows, comprising: a plurality of first and second air circulation networks stacked alternately according to a direction of stacking and separated two-by-two by membranes permeable to water vapor and impermeable to air and to liquid water, each one of the first and second air circulation networks comprising cells each defined by a wall comprising openings for passage of air, the cell wall comprising two opposing edges on which the cell is open in the direction of stacking, wherein for at least one of the first air circulation networks, at least one of the two opposing edges of each cell wall defines a hollow open in a direction of the second directly consecutive air circulation network, the hollow receiving a part of the second network.
2. The dual air flow exchanger according to claim 1, wherein for at least one of the second air circulation networks, at least one of the two opposing edges of each cell wall defines a hollow open in a direction of the first directly consecutive air circulation network, the hollow receiving a part of the first network.
3. The dual air flow exchanger according to claim 1, wherein the two opposing edges, of each cell wall of at least one of the circulation networks, each defining a hollow open in a direction of the directly consecutive network, and receiving a part of the directly consecutive network.
4. The dual air flow exchanger as claimed in claim 1, wherein the first and second air circulation networks each have identical structures, and for at least one first and one second directly consecutive networks in the stacking, the structure of the first network is shifted from the structure of the second network in the plane orthogonal to the direction of stacking, to allow the hollow of the first network to receive a part of the second network, and reciprocally.
5. The dual air flow exchanger as claimed in claim 1, wherein each first and second air circulation network is carried out using a mesh which is repeated, the mesh comprising the cell wall.
6. The dual air flow exchanger according to claim 5, wherein the mesh further comprises a connecting rod of the cells.
7. The dual air flow exchanger according to claim 5, wherein the mesh is identical for the first and second air circulation networks.
8. The dual air flow exchanger as claimed in claim 1, wherein each first and second air circulation network has a plane of symmetry orthogonal to the direction of stacking.
9. The dual air flow exchanger as claimed in claim 1, wherein the cells are cylindrical with a non-circular section and axes parallel to the direction of stacking.
10. The dual air flow exchanger as claimed in claim 1, wherein the cell wall has a global hexagon shape when viewed according to the direction of stacking.
11. The dual air flow exchanger according to claim 10, wherein the cell wall has six faces, of which two opposite faces arranged substantially parallel to a main direction of circulation of air through the network concerned, and two pairs of two faces passes through the air, with the two pairs being connected by the two opposite faces.
12. The dual air flow exchanger according to claim 11, wherein the two opposite faces of the cell wall are solid or perforated.
13. The dual air flow exchanger according to claim 11, wherein each pair comprises two faces of a globally triangular shape, with the two faces being connected to one another by one of their vertices.
14. The dual air flow exchanger according to claim 13, wherein each first and second air circulation network is carried out using a mesh which is repeated, the mesh comprising the cell wall, wherein the mesh further comprises a connecting rod of the cells, and wherein the connecting rod is connected to the vertex, from which the connecting rod protrudes in a plane orthogonal to the direction of stacking.
15. The dual air flow exchanger as claimed in claim 1, further comprising, associated with each air circulation network, an air distributor and an air collector, with the distributors and collectors being stacked according to the direction of stacking.
16. The dual air flow exchanger as claimed in claim 1, configured so that circulation of air inside the dual air flow exchanger is carried out at counter-current, or at co-current.
17. The dual air flow exchanger as claimed in claim 1, wherein the membranes are made from a polymer material or from paper.
18. The dual air flow exchanger as claimed in claim 1, wherein the networks are metal or of a polymer material.
19. A system for treating and conditioning air comprising a dual air flow exchanger, allowing for a heat transfer and a humidity transfer between two air flows, the dual air flow exchanger comprising: a plurality of first and second air circulation networks stacked alternately according to a direction of stacking and separated two-by-two by membranes permeable to water vapor and impermeable to air and to liquid water, each one of the first and second air circulation networks comprising cells each defined by a wall comprising openings for passage of air, the cell wall comprising two opposing edges on which the cell is open in the direction of stacking, wherein for at least one of the first air circulation networks, at least one of the two opposing edges of each cell wall defines a hollow open in a direction of the second directly consecutive air circulation network, the hollow receiving a part of the second network.
Description
(1) This description shall be provided with regards to the annexed drawings among which;
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(39) In reference first of all to
(40) By way of example, the vitiated air flow A can have a temperature of 22 C. before exiting the building, and the flow of fresh air B can have a temperature of 0 C. before entering the building. After heat transfer in the exchanger, the flow B can reach 20 C. when exiting the exchanger and entering the building, and the flow A can be cooled to a temperature of 2 C. when exiting the exchanger and the building. On this case, in heating mode, the incoming air is cold and dry, and the exchanger makes it possible to humidify and to preheat this incoming dry air to acceptable thermal comfort conditions. At the same time, the vitiated air is cooled and is discharged on the one hand of its humidity.
(41) However, other operating modes are possible. First of all, in air conditioning mode with the incoming hot and wet air, the exchanger makes it possible to dehumidify and to cool this incoming air to acceptable thermal comfort conditions. The vitiated air is heated and is loaded with humidity. Furthermore, in air conditioning mode with the incoming hot and dry air, the exchanger makes it possible to humidify and to cool the incoming air to acceptable thermal comfort conditions. Indeed, the vitiated air is heated and here is discharged on the one hand of its humidity.
(42) In order to allow for the circulation of the flows A and B, the system 100 is supplemented with two fans 104, shown diagrammatically in
(43) As mentioned hereinabove, the exchanger 1 is therefore also designed to provide a humidity transfer between these two flows A and B, from the most humid area to the driest area. This exchanger 1 is therefore qualified as total exchanger or an enthalpy exchanger.
(44) In
(45) In reference to
(46) Between the directly consecutive networks 2a and 2b in the direction 4, a polymer membrane 6 permeable to water vapour and impermeable to air and to liquid water is provided. It is therefore through these membranes 6 separating the networks two-by-two that the transfer of humidity between the two flows A and B is produced. Such membranes 6 are also referred to as imper-breathing membranes.
(47) The membranes 6 interposed between the networks 2a, 2b are therefore carried by the latter. As indicated hereinabove, the stacking 110 is inserted into the casing 106 of the exchanger in order to allow for the maintaining thereof, and conventional seals are placed at the periphery of the stacking 110 in order to provide a seal and prohibit communication between the networks 2a and the networks 2b.
(48) In this preferred embodiment, each membrane 6 has a uniform transverse section, defining a broken line of the triangle signal type. In other terms, as a section according to a cutting plane orthogonal to the length L of the stacking 110, each membrane 6 has alternately, according to the width I of this stacking, hollows and protrusions in the form of a triangle.
(49) In addition, two directly consecutive membranes 6 in the stacking are shifted by a half-period according to the width I, in such a way that the vertices of the triangles are located facing two-by-two according to the direction of stacking 4, as can be seen perfectly in
(50) More precisely, each first network 2a has channels 2a in the shape of a diamond, with these channels being arranged end-to-end according to the direction I, by being connected by their vertices. Similarly, each second network 2b has channels 2b in the shape of a diamond, with these channels also being arranged end-to-end according to the direction I, by being connected by their vertices. Once of the advantages of this configuration of the checkerboard type resides in the fact that each channel 2a is in contact with four channels 2b on its four sides, of which two channels 2b belonging to the directly upper network 2b in the stacking, and of which two other channels 2b belonging to the directly lower network 2b in the stacking. It is obviously the same for any channel 2b, that is in contact with four channels 2a on its four sides. With this arrangement, the exchange surface is increased, and the compactness is improved. It is moreover noted that a seal between the various channels of the same network is not expressly sought, as air can indeed pass from one to the other by passing through the location where the membranes come very close to one another, namely on their vertices forming the bow ties of the checkerboard.
(51) It is noted that this design of the checkerboard type can also be observed as a view according to the direction L such as that of
(52) The networks 2a, 2b has identical structures, carried out using the same mesh repeated in the plane of each network concerned. As can be seen in the
(53) Indeed, these figures show the mesh 16a allowing for the manufacture of the first network 2a. As indicated hereinabove, the mesh is the same for the manufacture of the second network 2b, of identical structure. Also, only the mesh 16a shall be described hereinafter. Moreover, it is noted that in all of the rest of the description, and in the figures, elements bearing numerical references ending with the letter b correspond to elements of the mesh of the network 2b, identical to the elements of the mesh of the network 2a bearing the same numerical references, and followed by the letter a.
(54) The mesh 16a has a plane of symmetry 17a which is orthogonal to the direction 4, and therefore also orthogonal to the axis 14a. This plane of symmetry 17a therefore constitutes a plane of symmetry for the entire network 2a, after repetition of the meshes 16a.
(55) The mesh 16a comprises a cell wall 18a that defines the aforementioned cell 12a. In order to reach the generally hexagon shape, the cell wall 18a comprises six planar faces, parallel to the direction 4. This first of all is two opposite faces 20a arranged substantially parallel to the main direction of circulation of the air through the network concerned, i.e. according to the direction L according to which also extend the channel. This then entails two pairs of two faces 22a passed through by air, and therefore being perforated as much as possible, in order to limit the load losses. Of course, the two pairs of faces 22a are connected to one another by the two opposite faces 20a.
(56) The faces 22a are each substantially triangular, connected two-by-two by one of their vertices 24a. As such, for the obtaining of the triangular shape and of the perforated nature, each face 22a has a base that corresponds to the edge of the adjacent face 20, and two straight reinforcements respectively forming the two sides of the triangle converging towards the vertex 24a with the other face 22a of the pair. The two vertices 24a are then located in the plane of symmetry 17a, on the future bow ties of the checkerboard. The armatures make it possible to define openings 26a for the passage of air at the inlet of the cell in the direction L, and at the outlet of the cell in this same direction.
(57) The cell wall 18a has two opposing edges 30a on which the cell is open in the direction of stacking 4. One of the particularities of the invention resides in structuring these edges, in such a way that they are no longer respectively inscribed in two parallel planes, as in prior art.
(58) More precisely, each edge 30a defines a hollow 32a in the cell wall 18, this hollows being open in the direction 4, in the direction of the directly facing network in the stacking. AS shall be detailed hereinafter, the presence of these hollows 32a allows for the nesting of the first and second networks 2a, 2b, and therefore the obtaining of the checkerboard configuration.
(59) The mesh 16a furthermore comprises a connecting rod 28a that extends protruding from one of the vertices 24a, substantially in the direction L and in the plane of symmetry 17a, namely orthogonally to the direction of stacking 4.
(60) In reference to
(61) Furthermore, for the manufacture of the networks 2a, 2b, it is noted that the materials considered are the polymer and metal materials, while the membranes 6 are preferentially made from a polymer material or from paper.
(62) For the manufacture of the networks 2a, 2b, the machining technique, although possible, is not preferred. Two other manufacturing techniques are favoured. In the two cases, options of partitioning the final network can be considered, especially if its dimensions are substantial.
(63) The first technique is the injection technique, more preferably plastic injection. In light of the geometric complexity of the air circulation networks, the partitioning can be carried out on the one hand in the directions L and I, but also especially in the direction of the height, corresponding to the direction 4. As such, a complete network can be an assembly of several parts, for example by mechanical fastening, or by heat welding.
(64) Metal injection, in particular the injection of aluminium, can also be considered, for example using a sand mould. Here also, a partitioning is preferred for the obtaining of the final network, forming a separator between two directly consecutive membranes in the stacking.
(65) The other favoured technique is that of so called additive manufacturing, or 3D printing. It indifferently applies for the obtaining of a metal network or in a polymer material. Here also, a partitioning can be considered, before reaching a final network. For the purposes of information, this may be a method of 3D printing of parts or assemblies of parts directly in imper-breathable polymer materials, wherein the membrane and the air circulation network would form only one part.
(66) In reference to
(67) By proceeding as such, on the edges 30a of the meshes 16a of the first network, the hollows 32a are filled in for a large part by the meshes 16b of the adjacent network 2b. More precisely, each hollow 32a of a first network 2a receives two wall-halves of two adjacent cells of the second network 2b, with these two wall-halves being also received, oppositely, by the hollows 32a belonging to the following network 2a in the stacking. The same applies for each hollow 32b of a second network 2b which received two wall-halves of two adjacent cells of the first network 2a, with these two wall-halves also being received, oppositely, by the hollow 32b belonging to the following network 2b in the stacking.
(68) It stems from this that each channel 2b of the network 2b, of which one is greyed in
(69) On the other hand, it is noted that no shift is carried out according to the direction L between two directly consecutive networks 2a, 2b, such as can be seen better in
(70) Multiple arrangements of shapes are possible with the elements described hereinabove. This can for example be faces 20a of which three alternative embodiments have been shown in
(71) Identical or similar solutions are also possible for the faces 20b of the cell walls of the second networks 2b.
(72) An assembly of two networks 2a, 2b, integrating perforated faces 20a, 20b as in
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(74) In reference to
(75) As such, when the meshes 16a are arranged in an adjacent manner according to the direction I, two directly consecutive half-meshes 16a form a channel 2a with a square section. This results in a global shape of a checkerboard for the channels 2a, 2b, as can be seen in
(76) In reference to
(77) With this configuration, it is arranged in such a way that when the meshes 16a are arranged in an adjacent manner according to the direction I, two directly consecutive half-meshes 16a form a channel 2a with a triangular section, more precisely in the shape of an equilateral triangle, as is shown in
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(79) To do this, each mesh 16a is also undulated according to the direction 4, as can be seen better in
(80) Regardless of the design retained, it is noted that the stacking has for example twenty superimposed networks 2a, 2b, and nineteen membranes 6 inserted between these networks. The maximum height of the channels 2a, 2b can be about 5 mm, while the thicknesses of the faces 20a, 22a and of the rods 28a can be about 0.5 mm.
(81) As mentioned hereinabove in reference to
(82) Just as for the networks 2a, 2b, on each side of the stacking of these networks, the distributors 112 and collectors 114 have identical structures, and are stacked alternately in one direction then in the other, in order to obtain the shift of a half-pas enabling them to be nested. On the other hand, for each network, the collector and the distributor associated with this network differ. Indeed, the rectangular air inlet 121a of the distributor and the rectangular air outlet 121b of the collector, which shall be described hereinafter, are symmetrically opposite in relation to the median axis of the exchanger. This allows for a balancing of the aeraulic paths for good irrigation of each channel.
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(84) As has been shown in
(85) In reference to
(86) Thanks to its turned-over position with respect to the distributor 112, the walls 126b as a diamond/square of the collector 114 are nested in the hollows defined between the walls 126a as a diamond/square of the distributor 112. As shown in FIG. 46, this allows each channel 2b to be located facing one of the air passages defined by the walls 126a. In addition, the nesting of the collector 114 and of the distributor 112 makes it possible ensure the compression of the aforementioned seal, between the outer surfaces facing the walls 126a, 126b.
(87) Of course, various modifications can be made by those skilled in the art to the invention that has just been described, solely by way of non-limiting examples.