PLATE HEAT EXCHANGER AND REVERSIBLE REFRIGERATING MACHINE INCLUDING SUCH AN EXCHANGER

This exchanger (1100), including superposed plates (2A-2L) which are inserted between two end plates (11, 12) and which define channels for circulation of heat-exchanging fluid. These channels delimit a first circuit (C1) for circulation of a first heat-exchanging fluid, comprising a single pass, and a second circuit (C2) for circulation of a second heat-exchanging fluid, comprising two passes opposite one another, so that, for each direction of circulation of the second heat-exchanging fluid in the second circuit, one of the two passes of the second circuit is co-current with respect to the pass of the first circuit, while the other of the two passes of the second circuit is counter-current with respect to the pass of the first circuit.

The present invention relates to a plate heat exchanger as well as to a refrigerating machine including such an exchanger.

FIG. 1shows a brazed plate heat exchanger100, provided with a set of superposed plates2A,2B and2C. Each plate2A,2B and2C has its opposite surfaces corrugated according to a precise scheme, for example, a chevron profile. The edges of the plates are provided with gaskets to prevent fluid leaks. The plates2A,2B and2C are arranged against one another, between two end plates11and12, so that the corrugated surfaces of two adjacent plates together define channels20for the circulation of heat-exchanging fluids.

Each plate2A,2B and2C and each end plate11and12comprises four openings each produced in one of their corners, namely a first opening21which is used as inlet E1for a first heat-exchanging fluid, a second opening22which is used as outlet S1for the first heat-exchanging fluid, a third opening23which is used as inlet E2for a second heat-exchanging fluid, and a fourth opening24which is used as outlet S2for the second heat-exchanging fluid. The channels20defined against each corrugated surface receive the first or the second heat-exchanging fluid. In the example ofFIG. 1, the first heat-exchanging fluid circulates in a first circuit between the second and third plates2B and2C. The second heat-exchanging fluid circulates in a second circuit which extends between the plates2A and2B. Thus, the first and second heat-exchanging fluids circulate alternately between two adjacent plates2A,2B and2C so as to ensure a transfer of thermal energy between the fluids.

FIG. 2shows a reversible refrigerating machine which includes a compressor400, a pressure reducing valve200and two exchangers100and300similar to the exchanger ofFIG. 1. These four elements are mounted on a common circuit C of refrigerant fluid. The exchangers100and300work alternately as condenser or evaporator depending on whether the refrigerating machine operates in heating mode or in air conditioning mode, the change in mode occurring by changing the direction of circulation of the refrigerant fluid in the common circuit C.

The first exchanger100implements a heat transfer between the common circuit C and a first exchange circuit C10. The second exchanger300implements a heat transfer between the common circuit C and a second exchange circuit C20.

For each operating mode, for example, one of the exchangers100and300runs counter-currently with respect to the exchange circuit C10or C20which interacts with this exchanger, while the other exchanger runs co-currently with respect to the other exchange circuit C10or C20.

The performances of a plate heat exchanger are better counter-currently than co-currently, so that for each operating mode, one of the exchangers100and300does not have an optimized yield.

DE 10 2006 002 018 discloses a reversible refrigerating machine which makes it possible to change the operating mode without reversing the direction of circulation of the refrigerant fluid, using a three-way valve installed on the refrigerating circuit. This solution is complex to implement, since it requires the installation of a device for distributing the refrigerant fluid.

These are the disadvantages that the invention aims to remedy more particularly by proposing a novel plate exchanger which is easy to use in a reversible refrigerating machine and which has a satisfactory yield.

To this effect, the invention relates to a plate heat exchanger including superposed plates which are inserted between two end plates and which define channels for circulation of heat-exchanging fluid, characterized in that the channels delimita first circuit for circulation of a first heat-exchanging fluid, comprising a single pass, anda second circuit for circulation of a second heat-exchanging fluid, comprising two passes opposite from one another,so that, for each direction of circulation of the second heat-exchanging fluid in the second circuit, one of the two passes of the second circuit is co-current with respect to the pass of the first circuit, while the other of the two passes of the second circuit is counter-current with respect to the pass of the first circuit.

According to advantageous but non-obligatory aspects of the invention, such an exchanger can incorporate one or more of the following features, considered in any technically acceptable combination:the first circuit comprises several intermediate branches each delimited between two adjacent plates and connecting to one another in parallel a forward branch and a return branch of the first circuit;the second circuit comprises two adjacent zones, in which intermediate branches of the second circuit belong, for one of these zones, to one of the two passes of the second circuit, and for the other zone, to the other of the two passes of the second circuit;the second circuit comprises a first portion and a second portion, which are separated by an intermediate plate of the exchanger and which are connected to one another by a conduit outside of the exchanger;the exchanger includes a tube which is provided with a slot distributing the second heat-exchanging fluid in several channels of the second circuit.

Another aspect of the invention relates to a reversible refrigerating machine including a common circuit of refrigerating fluid, on which are arranged a compressor, a pressure reducing valve and two exchangers which are each as defined above.

According to advantageous but non-obligatory aspects of the invention, such a refrigerating machine can incorporate one or more of the following features, considered in any technically acceptable combination:the refrigerating machine comprises a four-way valve capable of changing the direction of circulation of the refrigerant fluid in the common circuit;the common circuit is formed by the second circuit of the exchangers;the second circuit comprises an inlet and an outlet arranged at the top of the exchangers;the second circuit comprises an inlet and an outlet arranged at the bottom of the exchangers.

FIG. 3shows a plate exchanger1100according to the invention. It includes a first end plate11which defines a first external surface A of the exchanger1100, and a second end plate12which defines a second external surface B of the exchanger1100opposite the first surface A.

Twelve plates2A to2L are superposed, that is to say arranged successively, one against the other, between the end plates11and12. The plate2K is arranged against the first end plate11, and the plate2L is arranged against the second end plate12.

The end plates11and12and the plates2A to2L have an overall rectangular shape. The exchanger1100has an overall parallelepiped shape with rectangular base. M is used to designate an upper edge of the exchanger1100located at the top ofFIG. 3, and N is used to designate a lower edge of the exchanger1100parallel to the upper edge M and located at the bottom ofFIG. 3. The edges M and N are of small length and connect together long edges O and P of the end plates11and12and of the plates2A to2L, which are perpendicular to the short edges M and N. The long edge O is located in the foreground ofFIG. 3and the long edge P in the background.

Each plate2A to2L comprises two opposite rectangular surfaces which are corrugated according to a precise scheme which does not limit the invention, for example, a chevron profile. These corrugations are not represented inFIG. 3; they can be similar to those of the exchanger ofFIG. 1. The edges M, N,0and P of the plates2A to2L are provided with brazed gaskets, not shown, in order to prevent fluid leaks. The corrugated surfaces facing one another of two adjacent plates2A to2L together define channels for the turbulent circulation of heat-exchanging fluids, these channels not being shown inFIG. 3but possibly similar to the channels20ofFIG. 1.

In the direction of its thickness, the exchanger1100comprises a first zone Z1, between the first end plate11and the plate2E, and a second zone Z2, between the plate2F and the second end plate12. The zones Z1and Z2are adjoining. The first zone Z1is located on the side of the first surface A of the exchanger1100, and the second zone Z2is located on the side of the second surface B. The zones Z1and Z2divide the exchanger1100in two in its thickness, that is to say in a direction perpendicular to the end plates11and12and to the plates2A to2L.

The exchanger1100delimits two heat-exchanging fluid circuits C1and C2. For use in a refrigerating machine, the first circuit C1is provided for water and the second circuit C2for a refrigerant fluid. The first circuit C1corresponds to one of the exchange circuits C10or C20of the refrigerating machine ofFIG. 2, and the second circuit C2corresponds to the common circuit C.

The circuits C1and C2are defined so that the water circuit C1comprises a single pass, that is to say the fluid circulates between the edges N and M in a single direction, namely from bottom to top in the example ofFIG. 3. The refrigerant fluid circuit C2comprises two passes, namely an inlet pass in the zone Z2, where the refrigerant fluid circulates in a first direction, namely from bottom to top between the edges N and M, and an outlet pass in the zone Z1, where the refrigerant fluid circulates in a second direction opposite from the first direction, that is to say from top to bottom between the edges M and N.

This configuration results from the particular arrangement of the corrugations of the plates2A to2L and of the holes21to24produced in the corners of the end plates11and12and of the plates2A to2L as described below. The end plates11and12and the plates2A to2L are each provided with a number of holes between one and four, so as to guide the circulation of the fluids in the circuits C1and C2.

The hole21is located in a first lower corner, at the junction between the edges N and P. The hole22is located in a second lower corner, at the junction between the edges N and O. The hole23is located in a first upper corner, at the junction between the edges M and P. The hole24is located in a second upper corner, at the junction between the edges M and O.

For a first direction of circulation of the fluids in the circuits C1and C2, as defined inFIG. 3, an inlet E1of the first circuit C1is formed by a first hole21of the second end plate12, in the zone Z2. The first circuit C1comprises a first lower branch or forward branch C11in which the fluid circulates up to the plate2K, through holes21which are perforated in each plate2A to2J and2L. The first end plate11and the plate2K have no hole21. A second upper branch or return branch C12of the first circuit C1is defined between the plate2K and a hole23of the second end plate12, which defines an outlet S1of the first circuit C1in the second zone Z2. The first end plate11and the plate2K have no hole23. Between the plates2K and2L, the fluid circulates through holes23perforated in each plate2A to2J and2L.

Between the branches C11and C12, the first circuit C1comprises several intermediate branches C13to C18connected in parallel between the branches C11and C12. The intermediate branches C13to C18are represented in a rectilinear manner in the diagram ofFIG. 3, but in practice they meander in the pattern defined by the corrugations of the plates2A to2L.

The branches C13to C15are part of the second zone Z2, and the branches C16to C18are part of the first zone Z1.

Thus, in the zones Z1and Z2, the first circuit C1has a single pass from the edge N and towards the edge M. In other words, between the edges N and M and for the two zones Z1and Z2, the fluid circulates in the first circuit C1in a single direction, namely from bottom to top.

The remainder of the description concerns the second circuit C2. An inlet E2of the second circuit C2is formed by a hole22of the second end plate12, in the second zone Z2. The second circuit C2comprises a first lower branch C21, which extends exclusively in the second zone Z2and which connects the second inlet E2to a first and a second intermediate branch C22and C23connected in parallel between the lower branch C21and an upper branch C24. In the intermediate branches C22and C23, the fluid circulates from bottom to top, from the edge N to the edge M. The plates2F and2G have no hole22.

The upper branch C24extends through holes24perforated in the plates2B to21in zones Z1and Z2, and it is connected to two other intermediate branches C25and C26in which the fluid circulates from top to bottom, from the edge M to the edge N. The intermediate branches C25and C26connect in parallel the upper branch C24to a second lower branch C27, which extends exclusively in the first zone Z1, through holes22perforated in the plates2A to2C,2K and in the first end plate11, up to an outlet S2of the second circuit C2formed by the hole22of the end plate11, in the first zone Z1.

Thus, in the zone Z2, the second circuit C2has an inlet pass where the fluid circulates in a first direction, namely from the lower edge N and towards the upper edge M. In the zone Z1, the second circuit C2has an outlet pass where the fluid circulates in a second direction opposite from the first direction, namely from the upper edge M and towards the lower edge N.

FIGS. 4 and 5more diagrammatically again show the arrangement of the circuits C1and C2of the exchanger1100.FIG. 4corresponds to the first direction of circulation ofFIG. 3for the circuit C2, andFIG. 5to a second opposite direction of circulation.

The first direction of circulation ofFIGS. 3 and 4corresponds to a first operating mode, in which the exchanger1100operates by evaporation. In the second zone Z2, the refrigerant fluid of the circuit C2performs a first pass that is co-current with respect to the water of the circuit C1, it circulates from bottom to top between the edges N and M and, in the first zone Z1, the refrigerant fluid of the circuit C2performs a second pass that is counter-current with respect to the water of the circuit C1, it circulates from top to bottom between the edges M and N.

InFIG. 5, the direction of circulation of the refrigerant fluid in the second circuit C2is reversed. The direction of circulation of the water in the circuit C1remains unchanged. The inlet E2of the circuit C2becomes the outlet S2and vice versa. The exchanger1100then operates in a second mode, by condensation.

In this second mode, for the first zone Z1, the refrigerant fluid in the second circuit C2performs a first pass that is co-current with respect to the water of the first circuit C1, it circulates from bottom to top from the lower edge N towards the upper edge M, and, in the second zone Z2, the refrigerant fluid in the second circuit C2performs a second pass that is counter-current with respect to the water of the first circuit C1, it circulates from top to bottom from the upper edge M towards the lower edge N.

Thus, for each operating mode, the exchanger1100makes it possible for the refrigerant fluid of the circuit C2to perform a first pass that is co-current and a second pass that is counter-current with respect to the water of the circuit C1. In this manner, the thermal yield of the exchanger1100is improved, since, in each operating mode, the fluids of the circuits C1and C2circulate counter-currently for the zone corresponding to the outlet pass of the circuit C2.

FIGS. 6 and 7show a reversible refrigerating machine which includes a compressor400, a pressure reducing valve200, and two exchangers1100and1200each similar to the exchanger ofFIGS. 3 to 5. These four elements400,200,1100and1200are mounted on a common circuit C of refrigerant fluid.

The first exchanger1100implements a heat transfer between the common circuit C and a first exchange circuit C10. The second exchanger1200implements a heat transfer between the common circuit C and a second exchange circuit C20.

The exchangers1100and1200operate alternately as condenser or evaporator depending on whether the refrigerating machine operates in heating mode or in air conditioning mode. The change in mode occurs by changing the direction of circulation of the refrigerant fluid in the common circuit C using a four-way valve V1.

InFIG. 6, for the first operating mode, the exchanger1100operates by condensation, and the second exchanger it operates by evaporation. The valve V1is in a first position. The refrigerant fluid of the common circuit C circulates in a first direction. The first exchange circuit C10is a hot water circuit, and the second exchange circuit C20is a cold water circuit.

InFIG. 7, for the second operating mode, the exchanger1100operates by evaporation, and the second exchanger operates by condensation. The valve V1is in a second position. The refrigerant fluid of the common circuit C circulates in a second direction opposite from the first direction ofFIG. 6. The first exchange circuit C10is a cold water circuit, and the second exchange circuit C20is a hot water circuit.

For each operating mode, each of the exchangers1100and1200operates, for one of the zones Z1and Z2, counter-currently, while for the other zone Z2or Z1, the exchangers1100and1200operate co-currently.

More precisely, in the first operating mode represented inFIG. 6, and for each exchanger1100and1200, the first pass or inlet pass of the common circuit C in the zone Z2is performed co-currently with respect to the corresponding exchange circuit C10or C20, and the second pass or outlet pass of the common circuit C in the zone Z1is carried out counter-currently with respect to the corresponding exchange circuit C10or C20. This configuration corresponds to that ofFIG. 4.

In the second operating mode represented inFIG. 7and for each exchanger1100and1200, the first pass or inlet pass of the common circuit C in the zone Z1is performed co-currently with respect to the corresponding exchange circuit C10or C20, and the second pass or outlet pass of the common circuit C in the zone Z2is carried out counter-currently with respect to the corresponding exchange circuit C10or C20. This configuration corresponds to that ofFIG. 5.

InFIGS. 3 to 7, the exchanger1100is arranged according to a first orientation, in which the inlets E1and E2of the circuits C1and C2are arranged at the bottom of the exchanger1100, along the lower edge N. The fluid of the circuit C1, in the two zones Z1and Z2, and the fluid of the circuit C2, in the zone Z2for the configuration ofFIG. 4, and in the zone Z1for the configuration ofFIG. 5, circulate upwards, against the force exerted by gravity.

FIG. 8shows the exchanger1100according to a second orientation, in which the edge M is oriented towards the bottom, while the edge N is oriented towards the top. The inlets E1and E2of the circuits C1and C2are arranged at the top of the exchanger1100, along the upper edge M. The fluid of the circuit C1, in the two zones Z1and Z2, and the fluid of the circuit C2, in the zone Z1, circulate downward in the direction of the force exerted by gravity.

For the two orientations of the exchanger1100, the flow of the water in the circuit C1is counter-current with respect to the flow of the refrigerant fluid in the outlet pass of the circuit C2, that is to say the flow of the water is directed upward when the inlet E2and the outlet S2are at the bottom, as shown inFIGS. 4 to 7, and is directed downward when the inlet E2and the outlet S2are at the top, as shown inFIG. 8.

FIG. 9shows an exchanger2100according to a second embodiment of the invention, of the dual-circuit exchanger type. The elements of the exchanger2100similar to those of the exchanger1100bear the same reference numbers. Below, the elements of the exchanger2100that are similar to those of the exchanger1100are not described in detail.

As described below and in contrast to the exchanger1100, the exchanger2100comprises two independent refrigerant fluid circuits C2and C′2, which can implement two passes when they are connected to one another appropriately by means of a duct C3represented with dotted lines inFIG. 9. The duct C3is represented diagrammatically inFIGS. 10 and 11which are described in greater detail below.

The exchanger2100comprises two end plates11and12and eight corrugated plates2A to2H arranged between the end plates11and12. The exchanger2100also has an intermediate end plate13inserted between the plates2D and2E. The intermediate end plate13materially delimits the separation between the zones Z1and Z2.

The exchanger2100has a generally rectangular shape and comprises an upper edge M, a lower edge N, and two lateral edges O and P. The end plates11,12and13and the plates2A to2H are provided with holes21,22,23and/or24.

The first circuit C1provided, for example, for water in the case in which a refrigerating machine is used, comprises an inlet E1implemented by a hole24produced in the end plate11. The first circuit C1comprises a first branch or forward branch C11which starts from the inlet E1and passes through holes24produced in the plates2A to2G as well as in the intermediate end plate13. A second lower branch or return branch C12of the first circuit starts at the outlet S1and passes through holes22produced in the plates2A to2G as well as in the intermediate end plate13. Between the end plate11and the plate2H, the fluid circulates through holes22perforated in each plate2A to2G.

Between the branches C11and C12, the first circuit C1comprises several intermediate branches C13to C16connected in parallel between the branches C11and C12. The intermediate branches C13to C16are represented in a rectilinear manner in the diagram ofFIG. 9, but in practice they meander in the pattern defined by the corrugations of the plates2A to2H.

The branches C13and C14are part of the first zone Z1, and the branches C15and C16are part of the second zone Z2.

Thus, in the zones Z1and Z2, the first circuit C1has a single pass, from the upper edge M and towards the lower edge N. In other words, between the edges M and N and for the two zones Z1and Z2, the fluid circulates in the first circuit C1in a single direction, namely from top to bottom.

The remainder of the description concerns the circuits C2and C′2of refrigerant fluid.

The circuit C2comprises an inlet E20formed by a hole23produced in the end plate12. A first upper branch C21or forward branch of the circuit C2extends from the inlet E20and the plate2F, in the second zone Z2, through holes23produced in the plates2G and2H.

The circuit C2has an outlet S20formed by a hole21produced in the end plate12. A second lower branch C22or return branch of the circuit C2extends between the outlet S20and the plate2F, in the second zone Z2, through holes21produced in the plates2G and2H.

The branches C21and C22are connected to one another by an intermediate branch C23which is delimited between the plates2F and2G.

The circuit C′2comprises an inlet E′20formed by a hole21produced in the end plate11. A first lower branch C′21or forward branch of the circuit C′2extends between the inlet E′20and the plate2C, in the first zone Z1, through holes21produced in the plates2A and2B.

The circuit C′2comprises an outlet S′20formed by a hole23produced in the end plate11. A second upper branch C′22or return branch of the circuit C′2extends between the outlet S′20and the plate2C, in the first zone Z1, through holes23produced in the plates2A and2B.

The branches C′21and C′22are connected to one another by an intermediate branch C′23which is delimited between the plates2B and2C.

InFIG. 10, the refrigerant fluid in the circuits C2and C′2circulates in a first direction, and the connection between the circuits C2and C′2is implemented by means of a connection conduit C3which connects the outlet S20of the circuit C2to the inlet E′20of the circuit C′2. Thus, the outlet S′20of the exchanger2100as represented inFIG. 9becomes the outlet S2of the common circuit of heat-exchanging fluid formed by the combination of the circuits C2and C′2. The inlet E20becomes the inlet E2of the common circuit C2and C′2.

In the zones Z1and Z2, the first circuit C1has a single pass, from the edge M and towards the edge N. In other words, between the edges M and N and for the two zones Z1and Z2, the fluid circulates in the first circuit C1in a single direction, namely from top to bottom.

In the direction of circulation of the fluid ofFIG. 10, the second circuit C2and C′2comprises a first pass or forward pass in the zone Z2, where the fluid circulates co-currently in the circuit C2, and a second pass or return pass in the zone Z1, where the fluid circulates counter-currently in the circuit C′2.

InFIG. 11, the direction of circulation of the fluid in the circuits C2and C′2is reversed. The inlet E2is in the zone Z1at the beginning of the circuit C′2, and the outlet S2is in the zone Z2, at the outlet of the circuit C2.

In the direction of circulation of the fluid ofFIG. 11, the second circuit C2and C′2comprises a first pass or forward pass in the zone Z1, where the fluid circulates co-currently in the circuit C′2, and a second pass or return pass in the zone Z2, where the fluid circulates counter-currently in the circuit C2.

Thus, regardless of the direction of circulation of the fluid in the circuit C2and C′2, the exchanger2100comprises a pass that is co-current and a pass that is counter-current, which makes it possible to optimize the thermal exchanges.

Two exchangers similar to the exchanger2100and provided with the duct C3can be used in a reversible refrigerating machine, in a manner similar to the exchanger1100as implemented inFIGS. 6 and 7. For the two directions of circulation of the fluid in the common circuit C, each exchanger comprises two passes, namely the outlet pass which is counter-current and the inlet pass which is co-current, which promotes thermal exchanges regardless of the direction of circulation.

The machine can be a water-water refrigerating machine in which the fluids that are cooled and heated by the exchangers2100are water.

It is also possible to use an air-water refrigerating machine including a first air-fluid exchanger also referred to as “battery,” and a second exchanger with two passes, such as the exchanger2100.

The tube500is provided with a longitudinal slot501of width L. The slot501ensures the distribution of the fluid in the circuits C′2of the zone Z2of the exchangers3100and4100when they operate by evaporation. The slot501extends over most of the tube500, the slot being interrupted at the ends so that the rigidity of the tube is ensured. In service, the slot501is oriented vertically towards the bottom of the tube.

The exchanger3100is overall similar to the exchanger2100. It is provided with a connection conduit C3which connects two circuits C2and C′2to one another. The circuit C2comprises a single channel in the zone Z1, while the circuit C′2comprises three channels in the zone Z2. The tube501distributes the fluid in the channels of the circuit C′2of the second zone Z2when the exchanger operates by evaporation.

The route of the refrigerant fluid in the circuits C2and C′2, in reference toFIG. 14, is as follows for operation by evaporation: the fluid enters the channel of the circuit C2through an inlet E2located at the lower end N of the exchanger3100. The fluid rises in this channel and joins the conduit C3passing through an outlet S′2of the circuit C2. The fluid circulates in the conduit C3and enters the tube501through an inlet E′2located at the upper end M of the exchanger3100. The slot51distributes the fluid in the three channels of the circuit C′2. At the lower end N, on the opposite side from the tube501, the three channels are connected to an outlet S2of the exchanger3100. The detail of the route of the fluid in the three channels of the circuit C′2is indicated inFIG. 22.

The route of the refrigerant fluid in the circuits C2and C′2, in reference toFIG. 15, is the following for the operation by condensation in the opposite direction from the operation by evaporation: the fluid enters the channels of the circuit C′2through an inlet S2located at the lower end N of the exchanger3100. The fluid rises in these channels, enters the tube500through the slot501and joins the conduit C3, passing through an outlet E′2of the circuit C′2. The fluid circulates in the conduit C3and enters the circuit C2through an inlet S′2. At the lower end N, the circuit C2is connected to an outlet E2of the exchanger3100.

As for the thermal exchanges, the dual-pass exchanger3100achieves an optimal yield when there are two to four times more channels in the outlet pass of the circuit C′2than in the inlet pass of the circuit C2.

FIG. 16shows the exchanger3100with the inlet E2and the outlet S2of the circuit C2at the top for operation by evaporation.FIG. 17shows the exchanger3100with the inlet S2and the outlet E2of the circuit C2at the top for operation by condensation. There are two to four times more channels in the outlet pass of the circuit C′2than in the inlet pass of the circuit C2.FIGS. 18 and 19show the exchanger4100respectively for the operations by evaporation and by condensation with the inlet and outlet of the circuits C2and C′2at the bottom.FIGS. 20 and 21show the exchanger4100respectively for the operations by evaporation and by condensation with the inlet and the outlet of the circuits C2and C′2at the top. The exchanger differs from the exchanger3100in that it does not incorporate duct C3. The operation of the exchanger4100is similar to that of the exchanger3100.

FIG. 22shows the route of the fluid in a channel of the zone Z2of the exchanger ofFIG. 14or of the exchanger ofFIG. 18, operating by evaporation, with the slot501of tube500oriented vertically downward.

FIG. 23shows the route of the fluid in a channel of the zone Z2of the exchanger ofFIG. 16or of the exchanger ofFIG. 20, operating by evaporation, with the slot501of the tube500oriented vertically downward.

In the context of the invention, the embodiments can be combined with one another, at least partially.