WO2000050832A1

WO2000050832A1 - Plate heat exchanger with an integrated valve

Info

Publication number: WO2000050832A1
Application number: PCT/FR1999/003281
Authority: WO
Inventors: Joseph Marie Le Mer
Original assignee: Joseph Marie Le Mer
Priority date: 1999-02-24
Filing date: 1999-12-24
Publication date: 2000-08-31
Also published as: EP1155271B1; ATE292778T1; ES2241348T3; EP1155271A1; FR2790073B1; PT1155271E; DE69924647T2; FR2790073A1; DE69924647D1; AU1786700A

Abstract

The invention relates to a heat exchanger which is provided with superposed parallel plates defining two heat exchange areas, whereby a primary liquid circulates in one of said heat exchange areas and a secondary liquid circulates in the other. The invention is characterized in that it comprises an integrated three-way valve fitted with a flap (71) that can selectively occlude a supply orifice for the primary liquid, thereby allowing the primary liquid to escape once it has crossed the heat-exchanger stack in order to close the opening of the chimney (62) at the exit of said stack, enabling the primary liquid to flow directly without having to cross the heat exchange area of said heat exchanger. The inventive heat exchanger with an integrated valve can be produced at low cost and is highly compact. It can be used for a number of applications, especially in mixed domestic heating systems providing an instantaneous supply of hot sanitary water.

Description

PLATE HEAT EXCHANGER, WITH INTEGRATED VALVE

The present invention relates to a heat exchanger, and more specifically a heat exchanger of the type composed of a set of superimposed parallel plates which delimit two heat exchange chambers, one traversed by a primary fluid and the other by a secondary fluid, these two fluids circulating in the form of alternating thin layers, with trajectories nested one inside the other, the entry and exit of each fluid being made by a pair of mouths, called main, formed in a plate of end in the stack, via "wells", or entry and exit chimneys crossing the internal plates and communicating with the interstitial spaces constituting the corresponding enclosure.

This type of exchanger is well known, ^'and is used in many applications, when needed to heat or cool a fluid with another fluid; the heat exchanger plates are thin metal plates, thermally good conductor, generally made of stainless steel, which are stamped and assembled by brazing or by a connection by means of bolted flanges, with interposition of rubber seals.

The end plates of the stack have generally a thickness greater than the other, because it is they which have mouths - or connections - for connection of the heat exchanger pipes on ^inlet and outlet of two fluids.

Some fittings may be located on the upper plate, and the others on the lower plate; in other embodiments, all of the fittings are located on a single plate, for example the upper plate. The dimensions of the plates and their number are naturally a function of the application concerned and the power sought.

As an indication, in a domestic application in which ^the exchanger team a circuit capable of supplying said mixed a central heating installation, with the possibility of fetching hot water, the plates have a generally rectangular shape, with rounded corners, dimensions of the order of 20 x 10 cm; the internal plates have a thickness of the order of 0.3 mm, the lower plate a thickness of the order of 0.8 mm and the upper plate of the order of The total number of plates is generally between ten and thirty.

Advantageously, two families of plates are provided, which are stacked in an alternating manner, each type of plate having undulations or other stamped reliefs of special configuration, which channel the flow of each fluid in the enclosure which it has to traverse.

The arrangement is designed so that the two flows of fluids between which the heat exchange takes place follow a labyrinth trajectory and circulate against the flow of one another, in order to favor this exchange. An exchanger of this kind is described for example in the document

EP-A-0 61 1 941, which can be referred to if necessary.

Figures 1 and 2 appended to this patent application are diagrams which illustrate the manner in which such an exchanger is used within a mixed circuit for domestic use of the kind mentioned above. These figures represent an installation in accordance with the state of the art.

This comprises a primary central heating circuit I and a secondary domestic water drawing circuit II, which interfere with each other at the level of the plate heat exchanger 3. The circuit I comprises a heating source 1 of l circuit water

I; it is for example a boiler provided with a gas burner.

A suitable pump 15 ensures the circulation of water in this circuit I.

The water leaves the boiler 1 through a pipe 10, then passes, via a tube 2 in the shape of a "T", in a pipe 11, passes through the central heating radiators 100, and returns to the boiler 1 after having dissipated a part of his calories in radiators 100.

The return pipe comprises two pipes 12, 13, separated by a three-way valve 5; line 13 is connected to boiler 1, after passage through pump 15, via line 14.

In this application, central heating water is the primary fluid; the exchanger 3 is connected in parallel with respect to the radiators 100, the bypass being located upstream of the radiators by the "T" pipe 2, and downstream of these radiators by the three-way valve 5. references 30 and 31 the inlet and outlet mouths of the primary fluid in the exchanger 3, respectively. The "T" tube 2 is connected to the mouth 30 by a pipe 20; the circuit mouth 31 is connected to the three-way valve 5 by a pipe 50.

On secondary circuit II, reference 4 has designated a source for producing cold water; it can simply be a tap connected to the drinking water network provided in the house receiving this installation.

A device for using hot water has been designated by the reference 4 '; it is for example a tap or a shower head intended to supply hot water to the user.

There have been designated by the references 32 and 33 the inlet mouths and, respectively, the outlet of the secondary fluid, in this case the water of circuit II.

The source 4 is connected to the mouth 32 by a cold water supply pipe 40; the mouth 33 is connected to the use device 4 ′ by a hot water distribution pipe 41.

In the state of the circuits illustrated in FIG. 1, only the heating circuit I is in use.

The valve 5 is in a position such that the pipes 12-13 are placed in communication, the pipe 50 being, on the other hand, isolated. In this situation, the water supplied by the boiler travels exclusively through circuit I, as symbolized by the arrows F, ensuring the heating of the radiators 100.

FIG. 2 illustrates a situation in which a drawing of sanitary water is requested, for example by opening a tap provided in the use device 4 '.

This drawing automatically switches, via an appropriate control system known per se, the three-way valve 5, so as to close the outlet of the pipe 12, on the contrary ensuring communication between the pipe 50 and the pipe 13. In these conditions, the hot water which circulates along G in the circuit, is routed at the level of the "T" pipe 2 towards the exchanger 3.

It traverses the primary enclosure of the exchanger from its inlet 30 to its outlet 31, following a sinuous trajectory schematically illustrated and designated TP (primary trajectory). Hot water does not pass through the radiators 100 since the outlet of the pipe 12 is closed. The hot water passes exclusively through the exchanger 3, as symbolized by the arrows G, returning to the boiler via the pipes 13 -14, and the pump 15.

At the same time, due to the domestic water call, the water in secondary circuit II flows through the secondary enclosure of the exchanger, from inlet 32 to outlet 33, as symbolized by the trajectory line winding TS (secondary trajectory) and arrows H.

The heat exchange takes place within the stack of plates, and it is therefore hot water which reaches the use device 4 '. When the drawing is finished, the valve 5 switches back to its initial position allowing the radiators to be supplied.

Of course, these circuits are controlled in known manner to temperature setpoints.

As an indication, the water leaves boiler 1 at a temperature of the order of 80 ° C and returns to it at a temperature between 40 and 60 ° C, depending on the setting of the radiators.

In the secondary circuit, the respective temperatures of the cold water entering the exchanger 3 and the hot water leaving it are - still for information only - of the order of 15 ° C and, respectively, of the order of 45 ° C. The three-way valve 5 is very stressed, since it changes state with each drawing of sanitary water.

The price of such a valve and its connections and pipes connecting to the plate heat exchanger plays a significant role in the total price of the installation. This valve also has a large size, which goes against the permanent search for compactness in most applications where this type of installation is usable.

The state of the art in this area can be illustrated by document EP-A-0 614 061, which relates to a plate exchanger of the aforementioned type, on which the three-way valve is mounted.

A simple examination of FIG. 2 of this document makes it possible to understand the aforementioned size problem, the valve occupying a relatively large volume compared to that of the exchanger itself.

Document WO-97/00415 discloses a plate heat exchanger, in which a shutter valve is integrated. In fact, the embodiment illustrated in FIG. 5 of this document comprises a valve 25, the movable valve of which is adapted to selectively close the upper opening of one of the chimneys passing through the stack of the plate. With this arrangement, it is possible to pass, or all of one of the fluids within ^the stack in the heat exchange enclosure, or only a portion of this fluid, another portion passing directly in the space of greatest section which separates the upper plate from the adjacent plate.

This device therefore does not act as a three-way valve capable of fulfilling the function set out above. In the embodiment shown in Figures 3 and 4 of

WO-97/00415, it is possible to pass all of one of the fluids either within the stack, between the inlet and outlet chimneys (FIG. 4), or directly from a chimney to the other, by the space between the lower plate and the adjacent plate (Figure 3). This solution is however complex and requires the use of two separate tubular valves, each movable in one of the two chimneys. The function sought by this embodiment is not a simple circuit reversal by three-way valve as sought by the present invention, but a very specific orientation of the flow rates in a given application, such as heating a circuit oil in a heat engine.

The present invention aims to integrate into the plate exchanger a three-way valve system by an arrangement of very simple design and structure, which allows, on the one hand, to reduce very significantly the overall cost price of the valve-exchanger assembly, on the other hand significantly reduce their size.

Another objective of the invention is to be able, if desired, to maintain the exchanger at a certain temperature by the permanent presence of a certain flow rate of the primary fluid within the exchanger, although there is no have no sanitary drawing. Thus, when there is a request of sanitary draw-off, a setting temperature very fast ^hot water of the secondary circuit is obtained from the start of tilting of the three-way valve.

These objectives are achieved, in accordance with the invention, thanks to the fact that the exchanger comprises a three-way valve for the distribution of the primary fluid, which is integrated into the exchanger, one of the channels of which is constituted by the one of two main mouths through which the primary fluid passes, the other by the opening of the chimney of the primary enclosure adjacent to this mouth, and the third by an annex mouth formed in the same end plate as said main mouth, and disposed near said chimney opening, a channel stamped in this plate making these two mouths communicate, the valve comprising a valve capable of selectively closing either said chimney opening or said annex mouth.

Furthermore, according to a certain number of additional, non-limiting characteristics of the invention:

- The annex mouth is arranged coaxially opposite said chimney opening and the valve consists of a discoid piston movable in translation along the axis common to the mouth annex to the opening;

- It includes a means of electric or hydraulic control of the piston;

- This control means is fixed to the end plate opposite to the end plate in which the main and annex mouths are formed, the piston rod passing coaxially through the chimney;

- This control means is fixed to the end plate in which the main and annex mouths are formed, the piston rod passing coaxially through a tubular connection mounted in said annex mouth;

- To the other main mouth is also associated an annex mouth which is formed in the same end plate as it, and which communicates with it by a channel stamped in the latter;

- the three-way valve is located at the outlet of the primary enclosure. The invention also relates to a mixed domestic hot water distribution installation comprising a primary central heating circuit and a secondary sanitary drawing circuit, this installation being equipped with an exchanger as described above, connected in parallel to the central heating radiators, central heating water, supplied by a boiler, constituting the primary fluid, while sanitary tap water constitutes the secondary fluid

Other characteristics and advantages of the invention will appear from the description which will now be made of it, with reference to the accompanying drawings. In these drawings: - As already said, Figures 1 and 2 are diagrams illustrating the operating principle of a mixed heating circuit, producing instantaneous domestic hot water, as understood in the state of the art;

- Figures 3 to 6 show a first possible embodiment of an exchanger according to the invention;

- Figure 3 is a front view, cut by the broken plane III-III of Figure 4;

- Figure 4 is a top view of Figure 3;

- Figure 5 is a left view of Figure 3, cut by the broken plane N-N of Figure 4;

- Figure 6 is a left view of Figure 4, cut by the NI-NI plane.

Figure 7 is a diagram of an installation equipped with this exchanger, the latter being shown seen from above; - Figures 8 and 9 are diagrams similar to that of Figure 7, ^the heat exchanger there being shown from the side and in section, the installation being illustrated respectively in a state of heating and in a situation of sanitary water bailing hot;

- Figures 10 to 13 show a second possible embodiment of the exchanger;

- Figure 10 is a side view cut by the broken plane X-X of Figure 11;

- Figure 12 is a left view of Figure 10, cut by the broken plane referenced XII-XII in Figure 11; - Figure 13 is a left view of Figure 11, cut by the plane XIII-XIII;

- Figures 14, 15 and 16 are views similar, respectively, to those of Figures 7, 8 and 9 above, intended to illustrate the operation of this second embodiment; - Figures 17 to 20, 21 to 24 and 25 to 28 show, respectively, a third, a fourth and a fifth possible embodiment of the exchanger according to the invention, the different views which represent these embodiments having a organization similar to those of FIGS. 3 to 6 (for the first embodiment) and 10 to 13 (for the second embodiment). The two end plates of the stack have been designated by the references 300 and 301, the plate 300 corresponding to the upper plate and the plate 301 to the lower plate.

The internal plates of the stack, as already said, are of two different types, referenced 302, 303.

We designated by the reference ej the enclosure, constituted by the interstices between plates, in which the primary fluid of circuit I circulates.

The interstitial spaces constituting the other enclosure, through which the secondary fluid passes, have been designated by the reference e ₂ . In known manner, wells, or chimneys, crossing the plates transversely, communicate with these enclosures. Two diagonally opposite chimneys are provided for the inlet and outlet of the primary fluid, which communicate with the interstices e _\ ; similarly, two diametrically opposite chimneys are provided, communicating with the interstices e ₂ . In the first embodiment of FIGS. 3 to 6, all of the fluid inlet and outlet mouths are formed in the upper plate 300.

Has been designated by the references 30 and 61 the openings ^of inlet and outlet of the primary fluid, and by 32 and 33 the inlet orifices and outlet of the secondary fluid.

These mouthpieces are small cylindrical sleeves, with an axis perpendicular to the plates. In the examples illustrated, their external wall is threaded, to allow the connection of the pipes by means of complementary threaded connections, intended to be screwed there tightly. Any other waterproof connection mode is possible, of course.

In the drawings, the references CEi and CSi have been designated _. the inlet and outlet chimneys, respectively, of the primary fluid in the interstices e; CE ₂ and CS have designated the inlet and outlet chimneys, respectively, of outlet of the secondary fluid in the interstices e ₂ of the stack. The mouth 30 for entering the primary fluid is positioned coaxially opposite the chimney CEi, in a corner of the exchanger.

The inlet ports 32 and outlet 33 of the secondary fluid are arranged coaxially opposite the chimneys CE ₂ and CS respectively, in the angles adjacent to the angle which has just been mentioned. The chimney CS] _, at the outlet of the primary fluid, is located in the fourth angle, that is to say in the corner diagonally opposite to the chimney CΕ _\ . Coaxially, opposite this chimney CSi, is a mouth called annex 60, also formed in the upper plate 300.

The mouth 61 is offset with respect to the mouth 60 towards the central zone of the exchanger, parallel to its longitudinal edge (long side). An oblique orientation could be provided, depending on the desired positioning of the mouthpiece 61.

The two mouths 60 and 61 communicate with each other by a channel 6 formed by stamping in the upper plate 300; this channel has an approximately semi-cylindrical section; it forms a recess in the upper plate 300 which delimits with the underlying flat plate 303 (against which this upper plate is applied and fixed) a passage 600.

Channel 6 extends parallel to the long sides of the plates.

The set of mouths 30, 32, 33, 60 and 61 are cylindrical tubular sleeves, of the same diameter; unlike the other mouths, the mouth 60 is internally threaded, and receives a threaded tubular connection 8, screwed into this mouth 60. Any other sealed connection mode is possible, of course.

Coaxial with the mouth 60, but on the opposite side of the stack, that is to say in the lower plate 301, is formed a sleeve 63 similar to the sleeve 60, also tapped on its internal wall.

In this sleeve 63 is fixed by screwing a valve body 7. This valve comprises a piston rod 70 axially movable, in the axis common to the sleeve 63, to the chimney CS _t , to the mouth 60 and to the tubular body 8 The rod 70 crosses the chimney CSi, and its free upper end is provided with a shutter disc, or valve, 71.

Depending on whether the rod 70 is in a high position, shown in strong lines in FIGS. 3, 5 and 6, or in a low position, shown in broken lines, and referenced 70 ′ in these same figures, the disc 71 comes to bear against the planar annular base 80 of the connector 8 thus closing the base of this connector, or on the contrary, is applied against the edge of the upper opening 62 of the chimney CSi (valve disc referenced 71 ') closing said opening.

Of course, the diameter of the disc 71 is chosen to be slightly greater than the openings of the connector 8 and of the chimney CSi, while the mouth 60 has an internal diameter slightly greater than the diameter of the disc 71, in order to allow its introduction into the exchanger. . The means for translational control of the rod 70 are known means, electrically, hydraulically or pneumatically controlled.

It may in particular be an electromagnet or a linear actuator such as those used for controlling automobile carburetor valves, for example, or a membrane device controlled by the pressure difference existing on the circuit. sanitary during a drawing.

Of course, the rod 70 is guided in leaktight manner in the end plate of the exchanger, for example by means of suitable O-rings.

The discoid valve 71 is made of flexible and elastic material, such as an elastomeric synthetic material, capable of being applied in a sealed manner by each of its two opposite faces against the seat of the connector 8 or against the edge of the opening of the CSi chimney, while resisting the temperature differences encountered during operation.

The valve and its control device are for example of the same general type as the three-way valve which is the subject of document FR-A-2 719 101.

In an alternative embodiment, not shown, the rod 70 could extend beyond the obturator disc 71, inside the tubular connection 8, to be guided therein in translation by a ring integral with this connection, the mounting of the ring in the central part of this connection being made by radial mounting arms not obstructing the flow of the primary fluid inside the connection 8.

Thus, perfect axial guidance of the rod 70 is obtained. This is particularly advantageous when the number of plates is large and involves a rod 70 of great length. Referring to Figures 7 to 9, we will now describe the operation of this device.

The pipes equipping the two circuits I and II have been assigned the same reference numbers as in FIGS. 1 and 2 relating to the state of the art. It can be seen that the pipe 20 coming from the "T" pipe 2 is connected to the mouth 30, while the return pipe to the boiler 13 is connected to the mouth 61. The piping 12 located downstream of the radiators 100 is connected to the fitting 8 and the mouthpiece 60.

The conduits 40 and 41 of the secondary circuit II are connected respectively to the mouths 32 and 33. FIG. 8 shows a situation in which the radiators 100 are supplied.

In this state, the shutter valve 71 is in its low position, closing the chimney outlet 62. The outlet of the primary enclosure constituted by the interstitial spaces ej; is therefore blocked, so that the primary fluid from the boiler cannot pass through the exchanger.

All of the hot water supplied by the boiler 1 passes through the radiators 100, arrives in the exchanger via the pipe 12 and the connector 8, crosses the space 600 of the channel 6, and is evacuated therefrom through the mouth 61. through the pipes 13, 14, under the suction of the pump 15.

When there is sanitary drawing, the valve 7 automatically switches over, by raising the rod 70, symbolized by the arrow k in FIG. 9. The valve 71 then releases the outlet 62 from the chimney CSi, while closing the base of the tubular connector 60.

The downstream part of the pipe 12 is thus closed off, so that the hot water can no longer circulate in the radiators 100.

This water is therefore supplied via the "T" pipe 2 and the pipe 20 in the plate exchanger 3 (arrows G). Hot water runs through the interstitial spaces e _! of the exchanger, while the cold water from the secondary circuit II passes into spaces e ₂ , ensuring the desired heat exchange (arrows H).

The domestic water flows through the exchanger with entry through the mouth 32 and the chimney CE ₂ and exit through the chimney CS ₂ and the mouth 33.

The water in the primary circuit leaves the exchanger through the chimney CSi, the channel 6 and the mouth 61.

The valve 7 integrated into the exchanger constitutes, with the chimney CSi. the mouth 60 and the connector 8 and ^the mouthpiece 61 communicating therewith through the channel 6, a three-way valve having the same function as the valve 5 of Figures 1 and 2 but having an extremely simple structure and a compact configuration, which meets the desired objective.

The second embodiment illustrated in FIGS. 10 to 13 has a design identical to that of the first embodiment with regard to the integration of the three-way valve. On the other hand, it is distinguished by the additional integration in the exchanger of the "T" tubing.

To this end, an upper mouthpiece 36 is provided in the upper plate 300, which is arranged coaxially opposite the chimney CEi, in place of the mouthpiece 30.

This is offset longitudinally, the two mouths 30, 36 communicating with each other by a channel 35 of substantially semi-cylindrical section, stamped in the upper plate, with a configuration similar to that of channel 6. A space direct communication 350 between the mouths 30 and 36 is thus achieved.

As seen in Figures 14 to 16, the pipe 10 through which the hot water leaves the boiler 1 is connected to the mouth 30, while the mouth 36 is connected to the pipe 1 1. In the event of use of the installation for heating only

(situation illustrated in FIG. 15) the hot liquid passes directly from the piping 10 to the piping 1 1 via the mouth 30, the passage 350 and the mouth 36, the hot water not passing through the interstitial space of the plates , because the valve 71 is in the low position. On the other hand, in the event of sanitary drawing (figure 16), the valve being in the high position, the liquid coming from the boiler is routed within the stack (arrow G) in order to heat the secondary liquid.

The mouths 30, 36 and the channel 35 therefore fulfill the same function as the conventional "T" tube 2, which further improves the compactness of the assembly while lowering the cost price.

In the two embodiments which have just been described, all of the connection mouthpieces of the exchanger are provided on the same side of the latter, in the upper plate.

A different arrangement may be desired in certain applications, depending on the configuration of the space in which ^the heat exchanger must be installed and of the available volume.

Thus, in the third embodiment illustrated in FIGS. 17 to 20, the mounting of the three-way valve 7, the arrangement of the mouths 60, 61 and those of the channel 6, as well as the mouth 33 are identical to those of the two previous embodiments. On the other hand, the mouths 32, 30, 36, as well as the channel 35, assigned here the index "prime" are formed on the lower plate 301.

The operation of this embodiment is strictly identical to that of the second embodiment already described; only the connections of the fluid inlet conduits have a different configuration (through the bottom plate).

The fourth embodiment, which is illustrated in FIGS. 21 to 24, is generally similar to the first embodiment.

However, the three-way valve, referenced 9, is located and mounted on the upper plate 3.

The body of the valve is tubular and has a part 93 screwed into the mouth 30, coaxially with the chimney CSi.

This chimney is closed downwards by the bottom plate 301.

The valve body has an inlet pipe 92 which forms a right angle with the part 93, the assembly forming an "L" shaped conduit.

It is this part 92 which is connected to the line 12 which brings the primary liquid from the radiators.

The operation of the shutter valve 91 is the same as that described above, this valve being able to selectively occupy a high position in which it closes the tubular body 93 or a low position in which it closes the upper opening of the chimney CSj.

The advantage of this construction is that all of the projecting parts are on the same side of the exchanger, in this case on the side of the upper face, which is of interest for certain installations in which the exchanger is accessible only from one side.

It is of course possible to provide this embodiment with an integrated "T" tube similar to that of the second embodiment.

The fifth embodiment of the invention, which is illustrated in FIGS. 25 to 28, differs essentially from the previous one, in that the body of the valve, referenced 9 ', extends not axially but transversely with respect to to its tubular connection, referenced 93 '.

The latter is a cylindrical sleeve screwed coaxially into the mouth 60. Its opposite end 96 ′ is intended to be connected to the pipe 12. The valve has a piston 95 ′ constituted by a flat rod

(member) guided in translation by its longitudinal edges in grooves longitudinal formed in the inner wall of the tube 93 '. At the base of the flat rod 95 ′ is fixed a valve in the form of a washer 91 ′, capable of selectively closing, as in the previous embodiments, the upper opening of the chimney CSj _. , or the base of the tube 93 '. The valve body 9 ', arranged at right angles to the tubular connection 93', is an actuator capable of causing the pivoting of a control rod 90 'around its own axis.

The free end part of the rod 90 ′ is bent twice, so as to form a crank section 900 ′, which is located in the central part of the tube 93 ′, and enters a lumen 94 ′ formed in the rod flat piston 95 '.

This light is an elongated hole, perpendicular to the axis of the piston. The rod 90 'can pivot by an angle of the order of 120 °, thereby causing the piston 95', and therefore the shutter valve 91 'to be lowered or raised.

The light-shaped connection 94 ′ authorizes the transverse movement of the rod end 900 ′ during its pivoting.

Of course, the flat piston rod (frame) 95 'does not obstruct the passage of the primary fluid from the piping 12 to the channel space 600, when the valve is in the low position.

Note also that this member 95 'is arranged parallel to the longitudinal direction of the channel 6, which limits the pressure drop in the flow of primary fluid when it flows from the tube 93' to the mouth 61 via space 600. Thanks to this arrangement, it is possible to provide an orientation in the same direction of all the pipes connected to the exchanger, perpendicular to the plates of the exchanger.

It goes without saying that this embodiment can also be provided with an integrated "T" tube, like the second or the third embodiment.

The actuator of the rod 90 ′ is for example an electromagnet or an electric geared motor, with a rotary axis.

The integrated valve could be placed on the side of the entry of the primary fluid into the exchanger and, on the contrary, the "T" tubing (integrated or not) could be positioned on the other side, at the outlet of the exchanger, according to one arrangement similar to that illustrated in FIG. 1 of document FR-A-2 719 101 already cited.

It should be noted that, whatever the embodiment concerned, a valve could be provided whose tilting from shutter position to the other takes place not instantaneously, but with a certain slowness (a few seconds for example), of so as to avoid thermal shock in the exchanger.

It is also possible to provide for an incomplete closure of the shutter member when it is in the low position corresponding to the use of heating only (no sanitary drawing). Thus, a certain part of the primary fluid is authorized to pass through the exchanger, so as to maintain permanent heating of the plates.

Thanks to this arrangement, when there is a demand for sanitary water, a very rapid supply of hot water is obtained, since the exchanger is constantly kept preheated. This can be achieved in different ways, for example by providing small holes at the edge of the upper opening of the chimney CSi, which are not covered by the shutter disc, even when it is in the low position.

Although the object of the present invention has been described in a particular application, it goes without saying that such an exchanger can be used in different applications and for various fluids (liquid and / or gas), in particular in processes. various industries and in the field of automotive equipment.

Claims

1. Heat exchanger with superimposed parallel plates delimiting two heat exchange chambers, one traversed by a primary fluid and the other by a secondary fluid circulating in the form of alternating thin layers, the inlet and outlet of each fluid being made by a pair of orifices, said main, formed in an ^end plate via inlet and outlet chimneys passing through the internal plates and communicating with the constituent interstitial spaces of ^the corresponding enclosure, characterized in that it comprises a three-way valve for the distribution of the primary fluid, which is integrated into the exchanger, one of the ways of which consists of one (61) of two main mouths (30, 61) through which the primary fluid, the other by the opening (62) of the chimney of the primary enclosure adjacent to this mouth, and the third by an annex mouth (60) formed in the same extension plate remitted (300) as said main mouth (61), and disposed near said chimney opening (62), a channel (6) stamped in this plate (300) making these two mouths (60, 61) communicate, this valve comprising a valve capable of selectively closing either said chimney opening (62) or said annex mouth (60).

2. Exchanger according to claim 1, characterized in that said annex mouth (60) is arranged coaxially opposite said chimney opening (62) and that said valve (71, 91) consists of a discoid piston movable in following translation the axis common to the annex mouth (60) to the opening (62).

3. Exchanger according to claim 2, characterized in that it comprises an electric or hydraulic control means (7, 9, 9 ') of the piston (71, 91, 91').

4. Exchanger according to claim 3, characterized in that said control means (7) is fixed to the end plate (301) opposite to the end plate (300) in which the main mouths are formed (61 ) and annex (60), the rod (70) of the piston (71) passing coaxially through the chimney.

5. Exchanger according to claim 3, characterized in that said control means (9, 9 ') is fixed to the end plate (300) in which the main mouths (61) and annex (60) are formed, the rod (90, 95 ') of the piston (91, 91') passing coaxially through a tubular connection mounted in said annex mouth (60).

6. Exchanger according to one of claims 1 to 5, characterized in that the other main mouth (30) is also associated an annex mouth (36) which is formed in the same end plate as , and which communicates with it by a channel (35) stamped in the latter.

7. Exchanger according to one of claims 1 to 6. characterized in that said three-way valve is located at the outlet of the primary enclosure.

8. Mixed installation for domestic hot water distribution comprising a primary central heating circuit (I) and a secondary circuit (II) of domestic water drawing, characterized in that it is equipped with an exchanger conforming to one of the preceding claims, connected in parallel to the radiators (100) of the central heating, the water of the central heating, supplied by a boiler (1), constituting said primary fluid, and the sanitary tap water constituting said secondary fluid.