CA2800715A1 - Air-air heat exchanger - Google Patents

Abstract

Aeraulic heat exchanger (1) intended to equip a bypass ventilation system of a room comprising a plurality of plates (2) superimposed so as to form a stack (3), each plate (2) comprising a plurality of circulation forming a first air circulation volume (5) for a first air flow. The heat exchanger (1) further comprises spacing means arranged to keep the plates (2) at a distance from each other so as to define a space (10) between two neighboring plates (2), these different spaces (10) between plates (2) forming an air circulation volume for a second air flow, first means for closing the spaces (10) between the plates (2) at both ends (6, 7) ) of the exchanger, second sealing means (13), these second sealing means (13) comprising, near the ends of the exchanger, two openings (20, 21), respectively for the inlet and the outlet of the second air flow.

Description

Aeraulic heat exchanger The invention relates to a ventilation heat exchanger for a dual-flow controlled mechanical ventilation system, as well as a system controlled mechanical ventilation equipped with this exchanger.
Controlled mechanical ventilation system (VMC) means a system designed to renew the air inside a technical room or residential.
In order to reduce the losses by renewal of air, the Ventilation set up in a building is usually of the double-flows, including static double-streams that are characterized by the fact one static exchanger recovers calories from stale air extracted from the building for give them to the fresh air entering the building by free recovery sure the simple heat exchange by conduction. Given the evolution buildings, heating needs tend to decrease sharply.
Indeed, the progress achieved through the design and use of new materials in terms of insulation, glazing and bridge limitation thermal energy, have significantly reduced leakage thermal homes. However, in this type of habitat, it is necessary to to reduce the losses by renewal of air. Ventilation implemented square is therefore generally of the double flow type. In a double flow ventilation, an aeraulic network is intended for the air insufflation in the rooms main or living rooms, and a second network ensures the extraction of air in technical rooms or wet rooms. Mechanical ventilation double-flow controlled system includes two fans providing the same flow, one of which is intended to inject air into the building, and the other is intended to extract the air out of the building.
Very often the exchangers consist of plates of material glued to each other and (or welded aluminum) but whose plates delimit zones in contact on the welds.
The plates are generally identical.
In order to achieve a high performance heat exchanger, it is necessary to to benefit from a so-called counter-current exchange, ie for which the insufflation flow and extraction flow flow in directions substantially parallel but in opposite directions ..
The classical exchangers are therefore usually faced with a constructive difficulty by pointed shapes that allow the

2 flow separation by the plates themselves but what generates on large areas a non-optimized exchange since the flows are simply crossed, and this ultimately for a large proportion of the surface of the exchanger.
The document EP 2 071 267 describes a heat exchanger made from the stack of a plurality of parallelepipedic plates, called honeycombs, each having a plurality of airflow channels extending between two opposite ends of the plate, the other two ends being closed. This stack takes a parallelepipedic form and is made in such a way that the even plates and the odd plates of the stack have the ends into which the channels on respectively two opposite sides of the stack and on the other two lateral sides of the stack. In this way stacking present on each lateral side a succession of ends on which open air channels and closed ends;
plates pairs delineating a first volume of circulation and odd plates delimiting a second volume of circulation. In use, the air flows insufflation and extraction are each directed to a volume of traffic different, one in the channels of the even plates, the other in the channels of the odd plates.
In this configuration, the heat exchanges take place at plate interfaces across the entire width of the heat exchanger, the flows insufflation and extraction being crossed. Such heat exchangers present a number of disadvantages, the heat exchange is not optimized since the exchange takes place according to a cross schema, it requires for its design a significant number of plates and heat exchange is achieved through two thicknesses of walls, the bottom wall of a plate and the upper wall of the plate arranged below, which limits the performance of the heat exchanger.
The present invention aims to remedy these disadvantages.
The technical problem underlying the invention is to provide a heat exchanger which offers both an optimized heat exchange, in particular by the trajectory of the air flow of insufflation and extraction in exchanger, and reduced production costs compared to a heat exchanger using honeycomb plates. For this purpose, the invention relates to a interchange

3 ventilation system for a double flow ventilation system of a room comprising:
a plurality of identical and shaped plates parallelepiped, superimposed so as to form a stack of general parallelepiped structure, each plate comprising a plurality airflow channels running the full length of the plate, these channels being delimited by longitudinal partitions, all the channels of air circulation plates forming a first volume of circulation air adapted to guide a first flow of air in a first direction, on all the length of the exchanger between a first end and a second end of the exchanger, characterized in that it comprises spacing means arranged to keep the plates relative to each other so as to delimit a space between two neighboring plates, these different spaces between plates forming a air circulation volume adapted to guide a second air flow in a second direction substantially parallel to the first direction, first means for closing off each space between the plates at both ends of the exchanger, second means for closing off each space between the plates at the two longitudinal walls of the exchanger, that is to say those parallel to the circulation channels of the first air flow, these second shutter means comprising, in one and / or in the other of the two longitudinal walls, and near the two extremities of the exchanger, two openings, respectively for the entry and the exit of the second air flows arranged to guide the first and second air flows in opposite senses.
Such a heat exchanger using a stack of plates parallelepipedic whose channel plates delimit a first volume circulation of an airflow along the stack and the spacing between plates a second volume of circulation of an airflow along the stack, allows for a heat exchanger of simple design and cost reduced, since one of the circulation volumes is achieved by spacing enter plates, achieving optimized heat exchange since using an exchange thermal principle according to the principle of countercurrent flow over the entire length of the exchanger and through only a plate wall thickness.

4 Advantageously, the spacing means and the first sealing means are made using at least two pieces of end pieces disposed respectively at the first end and the second end of the exchanger.
The use of tip pieces arranged at both ends of stacking allows by the use of a single type of piece for, at a time, keep the plates apart and thus delimit the second volume air flow, and separate the first and second air flow.
Preferably, each piece of tip comprises:
- at least one housing for housing a side of a plate on which open the channels, this housing being provided with a through opening opening into the traffic channels formed by the channels of the plate housed there, at least one spacer forming the spacing means, the each spacer now remotely alone or in cooperation with a another spacer arranged on another piece of tip, a plate housed in the end piece of a directly adjacent plate in the stack, at least one closure member, such as, for example, a plate shutter, forming the first sealing means, this or each organ closing, alone or in cooperation with a closure member arranged on a another piece of tip, the space between a plate housed in the bit piece and a directly adjacent plate in the stack.
The use of a mouthpiece having at least one housing for each plate, at least one spacer and a closure member, allows a good distance between the successive plates, the plates being arranged in a housing and kept at a distance by the spacers, shutter members to complete the separation of air flows.
Advantageously, each spacer acts as an organ shutter.
The use of the spacers as shutter member allows guarantee a good sealing of the space between the plate since the shutter is performed over the entire thickness of the spacer.
Advantageously, the or all of the end pieces equipping the first / second end of the exchanger closes the edge of all the spaces between plates at the first / second end of the exchanger so as to separate the first and the second circulation volume at the first / second end of the exchanger.
The closing of one of the ends of the stack by the pieces end piece equipping this end allows a tight sealing spaces

5 between plates thus allowing a good separation between the input / output of the first volume of air circulation and the second volume of air circulation.
Preferably, the second closure means comprise longitudinal ribs arranged between two directly adjacent plates in the stack, these ribs closing off, during the formation of the stack, at least one longitudinal wall of the exchanger.
The use of ribs on the plates acting as a second closing means allows rapid assembly of the exchanger since not requiring the fitting of an additional part to close the longitudinal walls closed by the ribs.
Advantageously, the second sealing means include at least one closure plate attached to the wall longitudinal axis of the exchanger so as to seal, on this same longitudinal wall, each space between plates, this plate shuttering device preferably comprising second spacing means between plates such as spacers.
The use of a plate with spacers allows closing the wall over the entire height, with one piece.
Advantageously, the inlet and the outlet of the second flow of air are arranged on the same side wall of the exchanger.
Such positioning of the air flows allows the design of a Aeraulic circuit occupying limited space, air inlets and outlets himself finding on the same side.
Preferably, the entry and the exit of the second air flow are respectively disposed on one and the other of the side walls.
Such positioning allows adaptation of the exchanger thermal system for installation in a ventilation circuit whose entries and outlets for the second airflow are opposite without requiring the use of additional ventilation ducts.
Advantageously, the heat exchanger further comprises a double collector for two air flows arranged at each end of the stack, each manifold to separate and direct the flows air

6 from the air network to the corresponding circulation volume, or corresponding volume of traffic to the ventilation network, the separation flows being obtained by means of the one or more end pieces disposed on the end of the stack on which the collector is installed, a portion lying in the extension of the end of the stack serving as partition to separate the air flows.
Using an elongated portion of the tip piece forming a partition in cooperation with a double collector to separate flows air allows a reduction of the costs related to the realization of such an exchanger thermal.
Preferably, the heat exchanger further comprises a air diversion corridor delimited by a chute adjacent to the stack, an airflow collector and a flap mounted in the collector, movable enter two positions, a first position where he directs one of the air flows, preferentially the second, towards the first or preferably the second volume of circulation and a second position where he directs this same airflow towards the air diversion corridor.
Such a diversion corridor allows punctually transmission of air flows without carrying out a heat exchange between the first and second air flow thus allowing circulation in the circuit aeraulic without heat exchange when it is not required.
Preferably, the plates, the spacer means and the first sealing means are made of a plastic material.
The invention also relates to a ventilation system controlled mechanical double flow of a local, characterized in that it comprises a heat exchanger aeraulic as presented above.
According to one characteristic, the heat exchanger is arranged so that the first airflow circulating in the first volume of traffic of air from the exchanger is blown into the room, and the second air flow flowing in the second volume of air circulation of the exchanger is extracted from the local.
The second flow of air flows through the second volume of air circulation. When the second flow of air is extracted from a body of water, the one-it has a high hygrometry. Also, frost is often form inside the second circulation volume.

7 The second circulation volume is delimited by the spaces between plates and thus has a width sufficient to limit the risk obstruction by frost.
Anyway the invention will be well understood using the description which follows with reference to the attached schematic drawing representing, as a non-limitative example, of several embodiments of this aeraulic heat exchanger.
Figure 1 is a perspective view of a first exchanger;
Figure 2 is a perspective view on an enlarged scale of a alveolar plates forming the exchanger;
Figure 3 is a perspective view of a honeycomb plate with a longitudinal rim;
Figure 4 is a front view of a tip piece;
Figure 5 is a perspective view of a stack of plates according to the principle of realization of the heat exchanger made with a tip piece, Figure 6 is a longitudinal sectional view of Figure 5 according to the line AA;
Figure 7 is a front view of a heat exchanger equipped with specific collectors for both air flows;
Figure 8 is a perspective view of a heat exchanger equipped with double collectors for both air flows and a system of diversion of the air supply flow;
Figure 9 is a partial perspective view of the exchanger of the Figure 8 partially cut along the plane BB.
FIG. 1 shows a heat exchanger 1 aeraulic according to the invention intended to equip a dual flow ventilation system of a local having a first inflating air flow and a second air flow extraction. Such a heat exchanger 1 comprises:
a plurality of plates 2 superimposed so as to form a stack 3, each plate 2 comprising a plurality of channels longitudinal 4 of air circulation forming a first volume of circulation 5 for a first air flow between a first end 6 and a second end 7 of the exchanger, spacing means 8, 9 arranged to maintain distance the plates 2 relative to each other so as to delimit

8 a space 10 between two adjacent plates 2, these different spaces 10 between plates forming an air circulation volume 11 for a second air flow, first closure means 8, 9 of the spaces 10 between the plates at both ends 6, 7 of the exchanger 1, second closure means 12, 13 of the spaces between the plates 2 at the two longitudinal walls 14 of the exchanger 1, that is, ie those parallel to the circulation channels 4 of the first air flow, The plates 2 forming the stack 3 are, as illustrated by FIG. 2, hollow plates 2, of identical dimensions and shape parallelepiped made preferentially made of plastic. They each comprise a plurality of longitudinal channels 4 of section rectangular. The channels are delimited by vertical partitions and longitudinal. These plates 2 can, depending on the constraints of manufacture and needs, behave as shown in Figure 3, on one of the side, a rib 12 forming a spacing means with a plate neighbor.
When assembling the heat exchanger 1, the plates 2 are superimposed at a distance from each other so as to form the stack 3 with a space 10 between two adjacent plates 2.
The stack 10 thus formed is of parallelepipedal general structure.
The spacing between the plates 2 forms the volume of air flow 11 for a second air flow. Keeping at a distance between each plate 2 is obtained by the use of the first spacing means 8, 9 arranged on end pieces 16 positioned at each end 6, 7 of the stack 3.
These end pieces 16 are preferably made of plastic material. The tip pieces 16 each comprise, as the shows figure 4:
at least one housing 17 for accommodating one side of a plate 2 in which open the channels, this housing 17 being provided with an opening through 18 opening into the circulation channels 4 of the plate 2 which is housed there, at least one spacer 8, 9 forming the spacing means 8,

9, the or each spacer 8, 9 now remotely alone or in cooperation with another spacer arranged on another piece of tip, a plate 2 housed in the tip piece 16 of a directly adjacent plate in stack 3, at least one closure member 8, 9 forming the first closure means 8, 9, this or each member 8, 9 sealing, alone or in cooperation with a shutter member disposed on another piece of tip, the space 10 between a plate 2 housed in the tip piece 16 and a plate directly adjacent in the stack 3.
The height of the spacers is chosen to adapt the section of passage of the second flow to the desired aeraulic conditions, for example to take into account the pressure losses on the insufflation network and on the extraction network.
Each piece of tip 16 may comprise either a housing for a single plate 2, ie, as illustrated in FIGS. 4, 5 and 6, five ten dwellings. In the configuration with five housings, a tip piece 16 has four inner struts 8 separating the plates 2 arranged in the housings 18 of the part endpiece 16, and two outer spacers 9 arranged at each end of the tip piece 16. The outer struts 9 allow, in cooperation with an outer spacer of a bit piece directly adjacent in the stack 3, to close the space 10 between the stack formed by the plates housed 2 in the tip piece 16 and the plates housed in the tip piece directly adjacent in the stack 3.
In this way, all the pieces of tip 16 equipping a end 6, 7 of the exchanger 1 closes, as shown in Figure 7, the edge of the set of spaces 10 between plates 2 at the end 6, 7 of the exchanger 1. This shutter allows a separation between the first 5 and the second volume of circulation 11 of air at the end 6, 7 equipped of the tip pieces 16.
The exchanger 1 also includes, to close the walls longitudinal 14 of the heat exchanger 1 and so as to close the sides of the second circulation volume 11, second closure means 12, 13.
These second means 12, 13 may be, if the plates 2 used to make the exchanger 1 are provided, the ribs 12 arranged on a side of the plate 2. These ribs 12 seal the longitudinal wall 14 formed by the sides of the plates 2 on which they are arranged.
These second sealing means 12, 13 can also be a closure plate 13 fixed at the level of the longitudinal wall 14 of the exchanger 1 so as to close hermetically on the same wall 14, the spaces 10 between plates 2. This shutter plate 13 can also include, as illustrated in Figure 5, second means spacing 19 between plates 2 such as spacers 19. These means 19 facilitate the realization of the spacing between plates 2 during 5 of the heat exchanger assembly 1.
These second closure means 12, 13, which are made at means of ribs 12 or a closure plate 13, comprise in one and / or in the other of the two longitudinal walls 14, and near the ends 6, 7 of the exchanger 1, two openings 20, 21 for the second

10 circulation volume 11, respectively for the inlet 20 and the outlet 21 of second air flow.
During assembly, the heat exchanger is usually equipped with flow collectors 22, 23, these collectors being either collectors 22 specific to each flow as shown in FIGS. 1 and 7, or double collectors 23 for the two air flows as shown by the Figures 8 and 9.
For an assembly with simple collectors 22, the collectors are arranged at the levels of the inlet 20 and the outlet 21 of the second volume of circulation 11. The first part of the ventilation circuit, that of the insufflation flow, is sealingly connected to the inlet 6 and the outlet 7 of the first air circulation volume 5 by the end pieces 16.
The the second part of the ventilation circuit, that of the extraction flow, is connected tightly to the inlet manifold 22 and to the collector 22. In this way, the insufflation and extraction flows transit all two by the heat exchanger 1, the inputs and outputs of these flows being opposed, allowing a thermal exchange between the two flows flowing in against the current. The insufflation flow is thus warmed by the flow extraction limiting the thermal losses linked to the air renewal of the room.
For an assembly comprising double collectors 23, the Incoming and outgoing air flows are collected by the collectors 23. The separation of these two air flows and their respective guides to the inlet 6, 20 and the output 7, 21 corresponding are made through the parts 16. In fact, the tip pieces 16 may comprise, for a installation with a double collector 23, an elongate portion 24 in the extension of the end of the stack 3 acting as partition wall separation.

11 During an installation comprising a double collector 23, it is It is also possible to install a bypass installation, ie say, having an air diversion corridor 25. This type of exchanger The thermal system comprises, as shown in FIGS. 8 and 9, a chute 26 adjacent to the stack 3, delimiting the air bypass corridor 25, and a valve 27 bypass type mounted in one of the manifolds 23 so that it is mobile between two positions, a first position where it directs the second flow of air to the second circulation volume 11 and a second position where he directs that same airflow to the air diversion corridor 25. From this way the second airflow, the extraction flow can be, in function of positioning the valve 27, which is directed towards the second volume of circulation of the exchanger 1, thus allowing a heat exchange with the flow insufflation, either to the diversion circulation corridor 25, without exchange thermal.
When installing a heat exchanger with double manifolds 23 in a ventilation circuit, the first part and the second part of the ventilation circuit are connected to the collectors 23 of the heat exchanger 1, the insufflation flow directed towards the first air circulation volume 5 of the exchanger 1 and the extraction flow directed to the second volume of air circulation 11. Thus, on a principle similar to the use of a heat exchanger with collectors 22, an optimized thermal exchange, with the advantage additional, by the use of the valve 27 by pass, to provide uncouple thermally and periodically the flow of insufflation of the extraction stream.
It goes without saying that the invention is not limited to forms of this heat exchanger, described above as examples, it encompasses all the variants.

Claims (14)

1. Aeraulic heat exchanger (1) for a cooling system dual flow ventilation of a room comprising:
a plurality of identical and shaped plates (2) parallelepiped, superposed so as to form a stack (3) of parallelepipedic general structure, each plate (2) comprising a plurality of airflow channels (4) extending the full length of the plate (2), these channels (4) being delimited by longitudinal partitions (15) the set of air circulation channels (4) of the plates (2) forming a first air circulation volume (5) adapted to guide a first flow air in a first direction, along the entire length of the exchanger (1) between a first end (6) and a second end (7) of the exchanger (1), characterized in that it comprises:
spacing means (8, 9) arranged to maintain distance the plates (2) from each other so as to delimit a space (10) between two adjacent plates (2), these different spaces (10) between plates (2) forming an air circulation volume (11) adapted to guide a second flow of air in a second direction substantially parallel to the first direction, first closure means (8, 9) of each space (10) between the plates (2) at both ends (5, 6) of the exchanger (1), second closing means (12, 13) for each space (10) between the plates (2) at the two longitudinal walls (14) of the exchanger (1), that is to say those parallel to the circulation channels (4) of first air flow, these second sealing means (12, 13) comprising, in one and / or in the other of the two longitudinal walls (14), and near the two extremities (6, 7) of the exchanger (1), two openings (19, 20), respectively for the inlet and the outlet of the second flow of air arranged to guide the first and the second flow of air in opposite directions. 2. Aeraulic heat exchanger (1) according to the claim 1, characterized in that the spacing means (8, 9) and the first sealing means (12, 13) are made using at least two parts endpieces (16) disposed respectively at the first end (6) and the second end (7) of the exchanger (1). 3. Aeraulic heat exchanger (1) according to the claim 2, characterized in that each end piece (16) comprises:
at least one housing (17) for accommodating one side of a plate (2) on which the channels (4) open, this housing (17) being provided with a through opening (18) opening into the traffic channels (4) formed by the channels of the plate (2) housed therein, at least one spacer (8, 9) forming the spacing means (8, 9), the or each spacer (8, 9) now remotely alone or in cooperation with another spacer arranged on another piece of tip, a plate (2) housed in the end piece of a directly adjacent plate in the stack (3), at least one closure member (8, 9), such as, for example, a shutter plate, forming the first sealing means (8, 9), this or each member (8, 9) sealing, alone or in cooperation with an organ shutter disposed on another end piece, the space (10) between a plate (2) housed in the tip piece (17) and a directly adjacent plate in the stack (3). 4. Aeraulic heat exchanger (1) according to the claim 3, characterized in that each spacer (8, 9) serves as an shutter (8, 9). 5. Aeraulic heat exchanger (1) according to the claim 3 or 4, characterized in that the or all of the bit pieces (17) equipping the first / second end (6, 7) of the exchanger (1) closes the edge of all the spaces (10) between plates (2) at the level of the first / second end (6, 7) of the exchanger (1) so as to separate the first (5) and the second (11) circulation volume at the level of first / second end (6, 7) of the exchanger (1). 6. Aeraulic heat exchanger (1) according to one of the Claims 1 to 5, characterized in that the second closure means (12, 13) comprise longitudinal ribs (12) arranged between two plates (2) directly adjacent in the stack (3), these ribs (12) closing, during the formation of the stack (3), at least one wall longitudinal (14) of the exchanger (1). 7. Aeraulic heat exchanger (1) according to one of the Claims 1 to 6, characterized in that the second sealing means (12, 13) comprise at least one closure plate (13) fixed at the level of the longitudinal wall (14) of the exchanger (1) so as to close hermetically, on the same longitudinal wall (14), each space (10) between plates (2), this shutter plate (13) comprising preferably second spacing means (19) between plates (2) such as spacers (19). 8. Aeraulic heat exchanger (1) according to one of the Claims 1 to 7, characterized in that the inlet (20) and the outlet (21) of the second air flow are arranged on the same side wall (14) of exchanger (1). 9. Aeraulic heat exchanger (1) according to one of the Claims 1 to 7, characterized in that the inlet (20) and the outlet (21) of the second flow of air are respectively arranged on one and the other walls lateral (14). 10. Aeraulic heat exchanger (1) according to the claim 2 or one of claims 3 to 9 in combination with the claim 2, characterized in that it further comprises a collector of flux double air (22) for both air flows at each end (6, 7) of the stack (3), each manifold (22) for separating and directing the air flow from the ventilation network to the circulation volume corresponding (5, 11), or the corresponding traffic volume (5, 11) to the network aeraulic, the separation of the flows being obtained by means of the part or parts end piece (17) disposed on the end (6, 7) of the stack (3) on which the collector (22) is installed, an elongate portion (24) in the extension the end (6, 7) of the stack (3) acting as partition (24) for separate these flows. 11. Aeraulic heat exchanger (1) according to one of the Claims 1 to 10, characterized in that it further comprises a corridor of air branch (25) delimited by a chute (26) adjacent to the stack (3), an airflow collector (22) and a valve (27) mounted in the collector (22) mobile between two positions, a first position where it directs one of the flows air, preferentially the second, towards the first (5) or preferentially the second circulation volume (11) and a second position where it directs this same flow of air to the air diversion corridor (25). 12. Aeraulic heat exchanger according to any one Claims 1 to 11, characterized in that the plates, the means spacing and the first sealing means are made of a material plastic. 13. Controlled mechanical ventilation system with double flow of a room, characterized in that it comprises a ventilation heat exchanger according to any one of claims 1 to 11. 14. Controlled mechanical ventilation system with double flow according to claim 13, characterized in that the heat exchanger is arranged so that the first flow of air flowing in the first volume of air circulation (5) of the exchanger (1) is blown into the room, and the second flow of air circulating in the second volume of air circulation (11) of the exchanger (1) is extracted from the room.