WO2011161360A2 - Air-air heat exchanger - Google Patents

Abstract

Air-air heat exchanger (1) intended to be fitted to a room double-flow ventilation system comprising a plurality of plates (2) that are superposed to form a stack (3), each plate (2) comprising a plurality of flow channels forming a first air circulation volume (5) for a first air flow. The heat exchanger (1) further comprises spacer means designed to keep the plates (2) a distance apart so as to delimit a space (10) between two adjacent plates (2), these various spaces (10) between plates (2) forming an air circulation volume for a second air flow, first means for closing off the spaces (10) between the plates (2) at the two ends (6, 7) of the exchanger, second closing-off means (13), these second closing-off means (13) comprising, near the ends of the exchanger, two openings (20, 21), one for letting the second air flow in and the other for letting it out.

Description

 Aeraulic heat exchanger

 The invention relates to a ventilation air heat exchanger for a controlled dual-flow mechanical ventilation system, and a controlled mechanical ventilation system equipped with this exchanger.

 Controlled mechanical ventilation system (VMC) means a system designed to renew the air inside a technical or residential room.

 In order to reduce the losses due to air renewal, the ventilation installed in a building is generally of the double-flow type, in particular static double-flows, characterized by the fact that a static heat exchanger recovers the calories from the heat exchanger. stale air extracted from the building to give them fresh air entering the building by a free recovery on the simple heat exchange by conduction. Given the current evolution of 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 limiting thermal bridges, have significantly reduced the heat loss of homes. However, in this type of habitat, it is necessary to reduce the losses by renewal of air. The ventilation set up is therefore generally of the double flow type. In a double flow ventilation, a ventilation network is intended for the insufflation of air in the main rooms or rooms of stay, and a second network ensures the extraction of the air in the technical rooms or wet rooms. Controlled mechanical ventilation with double flow 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 outside the building.

 Very often the exchangers consist of plastic plates bonded 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 powerful heat exchanger, it should be possible to benefit from a so-called countercurrent exchange, that is to say for which the flow of insufflation and the flow of extraction flow in d irections substantially parallel but in opposite directions ..

Classical heat exchangers are therefore usually faced with a constructive difficulty with pointed shapes that allow the separation of the fluxes by the plates themselves but which generates on large surfaces a non-optimized exchange since the flows are simply crossed, and finally 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, so-called alveolar plates, each comprising a plurality of air circulation channels extending between two opposite ends of the plate, the other two ends being closed. This stack takes a parallelepipedal shape and is made in such a way that the even plates and the odd plates of the stack have the ends in which the channels open on respectively two opposite lateral sides of the stack and on the two other lateral sides. stacking. In this way the stack has on each lateral side a succession of ends on which open the air circulation channels and closed ends, the even plates delimiting a first circulation volume and the odd plates delimiting a second circulation volume. In use, the insufflation and extraction air streams are each directed to a different circulation volume, one in the even-plate channels, the other in the odd-plate channels.

 In this configuration, the heat exchanges take place at the interfaces between plates over the entire width of the exchanger, the flow of insufflation and extraction being crossed. Such heat exchangers have a certain number of disadvantages, the heat exchange is not optimized since the exchange takes place according to a crossed pattern, it requires for its design a large number of plates and the heat exchange is carried out at Through two thicknesses of walls, the bottom wall of a plate and the upper wall of the plate are placed 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 optimized heat exchange, in particular by the trajectory of the air flow of insufflation and extraction in the exchanger, and costs reduced production compared to an exchanger using honeycomb plates. For this purpose, the invention relates to a heat exchanger thermal ventilation for a ventilation system with a double flow of a room comprising:

 and a parallelepiped-shaped identical plate, superimposed so as to form a stack of parallelepipedal overall structure, each plate comprising a plurality of air-flow channels extending over the entire length of the plate, these channels being delimited by longitudinal partitions, the set of air circulation channels of the plates forming a first air circulation volume adapted to guide a first air flow in a first direction, over the entire 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 at a distance from one another so as to delimit a space between two adjacent plates, these different spaces between plates forming an air circulation volume adapted to guide a second flow of air. in a second direction substantially parallel to the first direction,

 first means for closing off each space between the plates at the two ends of the exchanger,

 second closing means for each space between the plates at the level of the two longitudinal walls of the exchanger, that is to say those parallel to the circulation channels of the first air flow,

 these second closure means comprising, in one and / or in the other of the two longitudinal walls, and near the two ends of the exchanger, two openings, respectively for the entry and the exit of the second flow of arranged to guide the first and second air flows in opposite directions.

Such a heat exchanger using a stack of parallelepiped plates whose plate channels delimit a first volume of circulation of an air flow along the stack and the spacing between plates a second volume of circulation of a flow of air along the stack, allows for a heat exchanger of simple design and low cost, since one of the circulation volumes is achieved by the spacing between plates, achieving an optimized heat exchange since using a heat exchange according to the principle of countercurrent flow over the entire length of the exchanger and through only a plate wall thickness. Advantageously, the spacing means and the first closure means are made using at least two pieces of tips disposed respectively at the first end and the second end of the exchanger.

 The use of end pieces arranged at both ends of the stack allows the use of a single type of room to both maintain the distance between the plates and thus delimit the second volume of circulation. air, and separate the first and second airflow.

 Preferably, each piece of tip comprises:

 - At least one housing for housing a side of a plate on which the channels open, this housing being provided with a through opening opening into the channels of circulation formed by the channels of the plate which is housed therein,

 at least one spacer forming the spacing means, the or each spacer now remotely alone or in cooperation with another spacer disposed on another piece of tip, a plate housed in the tip piece of a plate directly neighbor in the stack,

 - At least one closure member, such as for example a closure plate, forming the first closure means, this or each closing member, alone or in cooperation with a closure member disposed on another piece of nozzle, the space between a plate housed in the tip piece and a directly adjacent plate in the stack.

 The use of tip piece having at least one housing for each plate, at least one spacer and a closure member, allows a good maintenance distance between the successive plates, the plates being arranged in a housing and kept at a distance by the spacers, the shutter members to complete the separation of air flows.

 Advantageously, each spacer acts as a closure member.

 The use of the spacers as closure member ensures a good closure of the space between the plate since the closure 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 level of the first / second end of the the exchanger so as to separate the first and the second circulation volume at the first / second end of the exchanger.

 Closing one of the ends of the stack by the tip pieces equipping this end allows a tight sealing of the spaces between plates thus allowing a good separation between the inlet / outlet of the first volume of air circulation and the second volume of air circulation.

 Preferably, the second sealing means comprise longitudinal ribs arranged between two directly adjacent plates in the stack, these ribs sealing, during the formation of the stack, at least one longitudinal wall of the exchanger.

 The use of ribs on the plates acting as second sealing means allows rapid assembly of the exchanger since it does not require the mounting of an additional piece to seal the longitudinal wall or walls closed by the ribs.

 Advantageously, the second closure means comprise at least one closure plate fixed at the level of the longitudinal wall of the exchanger so as to hermetically seal, on this same longitudinal plane, each space between plates, this shutter plate preferably comprising second spacing means between plates such as spacers.

 The use of a plate with spacers allows the closure of the wall over the entire height, with one piece.

 Advantageously, the inlet and the outlet of the second air flow are disposed on the same side wall of the exchanger.

 Such positioning of the air flows allows the design of a ventilation circuit occupying a limited space, the air inlets and outlets being on the same side.

 Preferably, the inlet and outlet of the second air flow are respectively disposed on one and the other of the side walls.

 Such positioning allows adaptation of the heat exchanger for installation in a ventilation circuit whose inputs and outputs for the second air flow are opposite without requiring the use of additional ventilation ducts.

Advantageously, the heat exchanger further comprises a double collector for two flows of air at each extremity of the stack, each collector for separating and directing the air flows. either from the ventilation network to the corresponding circulation volume, or from the corresponding circulation volume to the ventilation network, the separation of the flows being obtained by means of the end piece or pieces placed on the end of the stack on which is installed the collector, an elongated portion in the extension of the end of the stack acting as a partition to separate the air flow.

 The use of an elongated portion of the end piece forming a septum in cooperation with a dual manifold for separating the airflows allows a reduction in the costs associated with realizing such a heat exchanger.

 Preferably, the heat exchanger further comprises an air diversion corridor delimited by a chute adjacent to the stack, an airflow collector and a valve mounted in the collector, movable between them positron, u first position where ildi rig a air flow, preferably the second, to the first or preferably the second volume of circulation and a second position where it directs the same air flow to the air diversion corridor.

 A derivation unit allows punctual transmission of the air flows without performing a heat exchange between the first and the second air flow thus allowing circulation in the air flow without heat exchange when the latter is required.

 Preferably, the plates, the spacing means and the first sealing means are made of a plastic material.

 The invention also relates to a dual mechanical controlled ventilation system of a room, 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 air flow flowing in the first air circulation volume of 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 air flow is extracted from a body of water, it has a high hygrometry. Also, it is common for frost to form inside the second circulation volume. The second circulation volume is delimited by the spaces between plates and thus has a width sufficient to limit the risk of obstruction by frost.

 In any case, the invention will be better understood with the aid of the description which follows with reference to the appended schematic drawing showing, by way of non-imitative example, 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 one of the honeycomb plates forming the exchanger;

 Figure 3 is a perspective view of a honeycomb plate with a longitudinal flange;

 Figure 4 is a front view of a tip piece;

 Figure 5 is a perspective view of a stack of plates according to the embodiment of the heat exchanger made with a tip piece;

 Figure 6 is a longitudinal sectional view of Figure 5 along the line A-A;

 Figure 7 is a front view of a heat exchanger equipped with specific collectors for the two air flows;

 Figure 8 is a perspective view of a heat exchanger equipped with double collectors for the two air flows and a bypass system of the air blowing flow;

 Figure 9 is a partial perspective view of the exchanger of Figure 8 partially cut along the plane B-B.

 FIG. 1 shows a heat exchanger 1 aeraulic according to the invention intended to equip a ventilation system with a double flow of a room comprising a first inflating air flow and a second extraction air flow. 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 longitudinal air flow channels 4 forming a first air circulation volume 5 for a first flow of air air between a first end 6 and a second end 7 of the exchanger,

spacing means 8, 9 arranged for keeping the plates 2 at a distance from one another so as to delimit a space 10 between two adjacent plates 2, these different spaces 10 between plates forming an air circulation volume 1 1 for a second air flow,

 first closure means 8, 9 of the spaces 10 between the plates at the two ends 6, 7 of the exchanger 1,

 second closure means 1 2, 1 3 spaces between the plates 2 at the two longitudinal walls 14 of the exchanger 1, that is to say those parallel to the flow channels 4 of the first flow of air,

 The plates 2 forming the stack 3 are, as illustrated in FIG. 2, hollow plates 2 of identical dimensions and of parallelepipedal shape preferably made of plastics material. They each comprise a plurality of longitudinal channels 4 of rectangular section. The channels are delimited by vertical and longitudinal partitions. These plates 2 may, depending on the manufacturing constraints and requirements, have as shown in Figure 3, on one side, a rib 12 forming a spacing means with a neighboring plate.

 During the assembly of the heat exchanger 1, the plates 2 are superimposed on 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 parallelepipedic general structure. The spacing between the plates 2 forms the air circulation volume 1 1 for a second air flow. The 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 plastics material. The tip pieces 16 each comprise, as shown in FIG. 4:

 at least one housing 17 for housing one side of a plate 2 into which the channels open, this housing 17 being provided with a through opening 18 opening into the circulation channels 4 of the plate 2 which is 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 disposed on another piece of tip, a plate 2 housed in the end piece 16 of an adjacent plate in the stack 3, at least one obturating element 8, 9 forming the first closure means 8, 9, this or each member 8, 9 sealing, alone or in cooperation with a closure member disposed on another piece of closure, nozzle, the space 10 between a plate 2 housed in the tip piece 16 and a directly adjacent plate in the stack 3.

 The height of the spacers is chosen to adapt the passage section of the second flow to the desired aeraulic conditions, for example to account for the pressure losses on the insufflation network and on the extraction network.

 Each end piece 16 may comprise either a housing for a single plate 2, or, as shown in FIGS. 4, 5 and 6, five housings or ten housings. In the configuration comprising five housings, a tip piece 16 has four inner struts 8 separating the plates 2 arranged in the housings 18 of the tip piece 16, and two outer struts 9 disposed at each end of the lap piece. 16. The outer struts 9 allow, in cooperation with an outer spacer of a piece of tip 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 bit piece directly adjacent in the stack 3.

 In this way, all the end pieces 16 equipping an end 6, 7 of the exchanger 1 closes, as shown in FIG. 7, the edge of the set of spaces 10 between plates 2 at the end of the end 6, 7 of the exchanger 1. This closure allows a separation between the first 5 and the second circulation volume 1 1 of air at the end 6, 7 equipped with the tip pieces 16.

 The exchanger 1 also comprises, to obtain the longitudinal regions 14 of the exchanger 1 and so as to close the sides of the second circulation volume January 1, second closure means 12, 13.

 These second means 12, 13 may be, if the plates 2 used for producing the exchanger 1 are provided, the ribs 12 disposed on one 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 closure means 1 2, 1 3 can also be a closure plate 13 fixed to the level of the long longitudinal wall 14 of the exchanger 1 so as to seal hermetically on the same wall 14, the spaces 10 between plates 2. This shutter plate 13 may also comprise, as shown in Figure 5, second spacing means 19 between plates 2 such as spacers 19. These spacing means 19 facilitate the realization of the spacing between plates 2 during the assembly of the heat exchanger 1.

 These second closure means 1 2, 1 3, whether made by means of ribs 12 or a closure plate 13, comprise in one and / or in the other two longitudinal walls 14, and near the ends 6, 7 of the exchanger 1, two openings 20, 21 for the second circulation volume 1 1, respectively for the inlet 20 and the outlet 21 of the second air flow.

 During assembly, the heat exchanger is generally 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 both. airflow as shown in Figures 8 and 9.

 For assembling with simple collectors 22, the collectors are arranged at the levels of the inlet 20 and the outlet 21 of the second circulation volume 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 second part of the The flow of ventilation, that of the extraction flow, is sealingly connected to the inlet manifold 22 and the outlet manifold 22. In this way, the insufflation and extraction flows both pass through the inlet manifold 22 and the outlet manifold 22. the heat exchanger 1, the inputs and the outputs of these flows being opposed, allowing a heat exchange between the two flows that flow against the current. The insufflation flow is thus warmed by the extraction flow limiting thermal losses associated with the renewal of room air.

For an assembly comprising double collectors 23, the incoming and outgoing air flows are collected by the manifolds 23. The separation of these two air flows and their respective guides towards the inlet 6, 20 and the outlet 7, 21 The end pieces 16 may comprise, for an installation with a double collector 23, an elongated portion 24 in the extension of the end of the stack. 3 acting as partition wall. During an installation comprising a double collector 23, it is also possible to make a "bypass" type installation, that is to say, comprising a branch of bypass 25. This type of heat exchanger comprises, as shown in Figures 8 and 9, a chute 26 adjacent to the stack 3, defining the air bypass corridor 25, and a valve 27 of the type "bypass" mounted in one of the collectors 23 of so that it is movable between two positions, a first position where it directs the second air flow to the second circulation volume 1 1 and a second position where it directs the same air flow to the bypass lane of In this way, the second flow of air, the extraction flow can be, depending on the positioning of the valve 27, is directed to the second circulation volume 1 1 of the exchanger 1, allowing a insi a heat exchange with the flow of insufflation, either towards the circulation corridor e derivation 25, without heat exchange.

 During the installation of a heat exchanger having double collectors 23 in a ventilation circuit, the first part and the second part of the ventilation circuit are connected to the double collectors 23 of the heat exchanger 1, the flow of the heat exchanger. blowing d irigé to the first volume of air circulation 5 of the exchanger 1 and the extraction flow directed to the second volume of air circulation 1 1. Thus, on a principle similar to the use of an exchanger comprising simple collectors 22, an optermed thermal emitter is obtained, with the same additional advantage, by the use of the valve 27. "By pass", to provide thermally and periodically uncoupling the flow of insufflation of the extraction stream.

 As goes without saying, the invention is not limited to the embodiments of this heat exchanger, described above as examples, it encompasses all variants.

Claims

1. Aeraulic heat exchanger (1) for a dual flow ventilation system of a room comprising:  a plurality of identically parallelepiped-shaped plies (2) superposed so as to form a stack (3) of parallelepipedal overall structure, each plate (2) comprising a plurality of air circulation channels; (4) extending over the entire 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 airflow volume (5) adapted to guide a first flow of air in a first direction over 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 keep the plates (2) at a distance from one another so as to delimit a space (10) between two adjacent plates (2), these different spaces (10) between plates (2) forming an air circulation volume (1 1) adapted to guide a second air flow in a second direction substantially parallel to the first direction,  first closing means (8, 9) of each space (10) between the plates (2) at the two 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 the first air flow, these second closure means (12, 13) comprising, in one and / or in the other of the two longitudinal walls (14), and near the two ends (6, 7) of the exchanger (1) two apertures (1 9, 20) respectively for the inlet and the outlet of the second air flow arranged to guide the first and the second air flow in opposite directions. 2. Aeraulic heat exchanger (1) according to claim 1, characterized in that the spacing means (8, 9) and the first closure means (1 2, 1 3) are made using at least two pieces of tips (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 housing a side of a plate (2) on which the channels (4) open, this housing (17) being provided with a through opening (18) opening into the channels (4). ) of circulation formed by the channels of the plate (2) which is housed therein,  at least one spacer (8, 9) forming the spacing means (8, 9), the or each spacer (8, 9) now at a single distance or in cooperation with another spacer disposed on another piece of end piece, 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 closure plate, forming the first closure means (8, 9), this or each member (8, 9) closing, only l or in cooperation with a closure member disposed on another bit piece, the space (10) between a plate (2) housed in the bit 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) acts as a closure member (8, 9). 5. Aeraulic heat exchanger (1) according to claim 3 or 4, characterized in that the or all of the nozzle parts (17) equipping the first / second end (6, 7) of the exchanger (1). closes the edge of the set of spaces (10) between plates (2) at the first / second end (6, 7) of the exchanger (1) so as to separate the first (5) and the second ( 1 1) circulation volume aun ivea udela first / second end (6, 7) of the exchanger (1). 6. Aeraulic heat exchanger (1) according to one of claims 1 to 5, characterized in that the second closure means (1 2, 1 3) comprise ribs (12) longitudinal disposed between two plates (2) directly adjacent in the stack (3), these ribs (12) closing, during formation of the stack (3), at least one longitudinal wall (14) of the exchanger (1). 7. Aeraulic heat exchanger (1) according to one of claims 1 to 6, characterized in that the second closure 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 hermetically seal, on the same longitudinal wall (14), each space (10) between plates (2), this sealing plate (13) preferably comprising second spacing means (19) between plates (2) such as spacers (19). 8. Aeraulic heat exchanger (1) according to one of 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 the exchanger (1) - 9. Aeraulic heat exchanger (1) according to one of claims 1 to 7, characterized in that the inlet (20) and the outlet (21) of the second air flow are respectively disposed on one and the other side walls (14). 10. Aeraulic heat exchanger (1) according to claim 2 or one of claims 3 to 9 in combination with claim 2, characterized in that it further comprises a dual air flow collector (22) for the two air flows disposed at each end (6, 7) of the stack (3), each manifold (22) for separating and directing the air flows from the air flow network to the corresponding circulation volume (5, 11), or the corresponding circulation volume (5, 11) to the ventilation network, the separation of the flows being obtained by means of the one or more end pieces (17) disposed on the end (6, 7) of the stack (3) on which is installed the collector (22), an elongated portion (24) in the extension of the end (6, 7) of the stack (3) acting as partition (24) to separate these flux. 1 1. Aeraulic heat exchanger (1) according to one of claims 1 to 10, characterized in that it further comprises an air bypass (25) defined by a chute (26) adjacent to the stack (3). ), an airflow collector (22) and a valve (27) mounted in the collector (22) movable between two positions, a first position where it directs one of the air flows, preferably the second, towards the first (5) or preferably the second circulation volume (1 1) and a second position where it directs the same air flow to the air diversion corridor (25). 12. Aeraulic heat exchanger according to any one of claims 1 to 1 1, characterized in that the plates, the spacing means and the first closure means are made of a plastic material. 13. Controlled mechanical ventilation system with a double flow of a room, characterized in that it comprises a heat exchanger aéraulic according to any one of claims 1 to 1 1. 14. Controlled mechanical ventilation system with double flow according to claim 13, characterized in that the heat exchanger is arranged so that the first air flow flowing in the first volume of air circulation (5) of the exchanger (1) is blown into the room, and the second flow d'a ir circulating in the second flow circulation a ir ir (1 1) of the exchanger (1) is extracted from the local.