FR3104687A1 - Thermal device for motor vehicle - Google Patents

Abstract

Thermal device for a motor vehicle Thermal device for a motor vehicle comprising at least one heat exchange surface and at least one connection block (12) which borders the heat exchange surface, the heat exchange surface comprising a series of tubes (4) parallel to each other and extending in a main direction of elongation parallel to a vertical direction (V) of the thermal device, at least one of the tubes (4) comprising a cooling channel (62) and an element heating. Abstract figure: Figure 3

Description

Motor vehicle thermal device

The present invention relates to the field of ventilation, heating and/or air conditioning installations of a motor vehicle and it relates more particularly to thermal devices for heating or cooling a flow of air passing through an air duct. such a facility.

More particularly, the invention relates to a thermal device provided with at least one electrical resistance heating element with a positive temperature coefficient, known as PTC effect heating elements, which is capable of rapidly producing a supply of heat and at least one refrigerant fluid circuit capable of cooling a fluid. Such heating elements make it possible, in particular when starting the vehicle in cold weather, to heat a flow of air passing through an exchange surface of the electric thermal device before it enters the passenger compartment of the vehicle while the fluid circuit coolant cools the vehicle interior in hot weather. Such an electric heating device is thus capable of transforming electrical energy stored on the vehicle into thermal energy restored in the flow of air passing through the device, but it is also capable of being traversed by a refrigerant fluid capable of yielding cold temperatures to this airflow.

Usually, the PTC effect heating elements and the refrigerant fluid distribution circuits are arranged in separate thermal systems. A disadvantage of such a device is that it requires a plurality of heat exchangers for the same motor vehicle in order to ensure both good heating of the passenger compartment in cold weather when starting the motor vehicle and cooling of the passenger compartment during high outside temperatures, and therefore involves bulk which may be incompatible with the space left in the corresponding compartment, for example in a box of a ventilation, heating and air conditioning system (HVAC for “Heating, Ventilating, Air Conditioning) of the vehicle.

The invention falls within this context and aims to propose an alternative to this configuration of thermal devices, in particular by reducing the quantity of thermal devices necessary in a motor vehicle while offering improved thermal performance.

The invention thus relates to a thermal device comprising at least one heat exchange surface and at least one connection block which borders the heat exchange surface, the heat exchange surface comprising a series of parallel tubes between them and extending in a main direction of elongation, each tube being connected to the connection block and at least one of the tubes being traversed by a refrigerant fluid, the thermal device being characterized in that at least one of the tubes traversed by the refrigerant fluid comprises at least one PTC effect heating element.

The thermal device can for example be a heat exchanger making it possible to heat and/or cool the passenger compartment of a motor vehicle, the exchange surface constituting the part of the thermal device within which the thermal exchanges take place in order to to heat or cool a flow of air passing through the thermal device and capable of being subsequently sent into the passenger compartment.

The exchange surface comprises the series of tubes parallel to each other and radiating elements arranged between the parallel tubes. The radiant elements, in the form of corrugated sheet metal forming a succession of fins, have the particular function of increasing the heat exchange surface with the fluid passing through the heat exchange surface of the thermal device and thus increasing the quantity of calories. likely to be transferred to the fluid.

Each radiant element is in contact with one or two adjacent tubes, the contact between the tubes and the radiant elements making it possible in particular to diffuse the thermal energy produced in the tubes to the radiant elements. The radiant elements can for example be brazed with the tubes in order to ensure a reliable connection between the radiant elements and the tubes.

According to a feature of the invention, the connection block is arranged to accommodate at least one electrical network and a coolant supply channel.

To this end, the connection block comprises a refrigerating chamber and an electrical chamber separated from each other by an internal partition. The refrigerating chamber then functions as a collecting chamber in that it collects the refrigerating fluid in order to distribute it in the tubes. The electrical chamber accommodates the electrical network ensuring the electrical supply to the heating elements of the thermal device. The internal partition provides a seal between the two chambers to prevent the refrigerant fluid from entering the electrical chamber.

According to one characteristic of the invention, at least one tube defines an internal cavity, the internal cavity providing at least one cooling channel and at least one heating channel, the cooling channel allowing the circulation of the cooling fluid and the heating channel housing the element heating.

In other words, the tubes are hollow and they include an internal face, which delimits the internal cavity housing the cooling and heating channels. Furthermore, these tubes have an outer face which corresponds to the face in contact with the radiating elements and with the fluid passing through the heat exchange surface.

According to one characteristic of the invention, the tube comprises a first transverse end and a second transverse end, opposite the first transverse end in a transverse direction perpendicular to the main direction of elongation of the tubes, and substantially parallel to the main direction of flow of the fluid passing through the thermal device, the heating channel being arranged at the first transverse end of the tube.

In other words, the heating channel and the cooling channel are arranged in the corresponding tube by being arranged one after the other along the flow direction of the fluid passing through the thermal device. Such a configuration makes it possible to place the cooling channel at the inlet of the thermal device, that is to say on the side where the fluid enters the thermal device, and to place the heating channel at the outlet of the thermal device, that is i.e. the side where the fluid exits into the thermal device.

According to one characteristic of the invention, the internal cavity of the at least one tube comprises a plurality of cooling channels and a plurality of heating channels, arranged alternately in the internal cavity of the tube.

The alternation of the channels is considered along the transverse dimension of the corresponding tube, i.e. parallel to the direction of the fluid brought to pass through the thermal device. In other words, the heating channels are distant from each other, in the sense that they are separated from each other by at least one cooling channel. In the same way, the cooling channels are distant from each other, in the sense that they are separated from each other by at least one heating channel.

According to one characteristic of the invention, the PTC-effect heating element comprises at least one metallic conductor embedded in a PTC-effect polymer matrix.

The heating element may in particular comprise two metal conductors, extending side by side, embedded in a matrix of PTC-effect polymer. These conductors can be made of a copper-nickel alloy.

According to one characteristic of the invention, the heating element is a heating film placed against one side of the tube.

In other words, the heating element takes the form of a sheet whose thickness is less than the thickness of the wall which delimits the tube. The film forming the heating element can then be placed against the internal face of the tube, this configuration requiring that an insulation layer be superimposed on the heating film so that the interaction with the refrigerant fluid circulating in the internal cavity of the tube does not alter the thermal performance of the heating film. Alternatively, the film forming the heating element can be placed against the outer face of the tube, this configuration requiring the radiating elements to be fixed by gluing with the tubes.

According to one characteristic of the invention, each of the tubes of the exchange surface is traversed by the refrigerant fluid and comprises the at least one heating element.

According to a variant of the invention, the thermal device further comprises an additional connection block, such that the connection block and the additional connection block are positioned on either side of the exchange surface and the elements heaters of the exchange surface are divided into a first set and a second set, the first set being electrically connected to the connection block and the second set being electrically connected to the additional connection block.

In this variant, the thermal device therefore comprises two connection blocks.

According to an example of the invention, the first set of PTC effect heating elements may correspond to a first part of the series of tubes and the second set of PTC effect heating elements corresponds to a second part of the series of tubes arranged in the continuity of the said first part.

An advantage of such a configuration of the thermal device lies in particular in the fact that it allows independent control of the first set of heating elements and of the second set of PTC effect heating elements. Indeed, the two sets are connected to separate internal electrical networks allowing the power supply of one or the other of the sets independently or simultaneously. This configuration is therefore advantageous for example in the context of heating the passenger compartment of a motor vehicle, since it is then possible to independently heat different areas of the passenger compartment and for example to independently heat the passenger space of the driver space.

The invention also relates to a heat exchanger composed of at least one layer comprising the thermal device as previously described.

According to a first configuration, the heat exchanger can comprise a single sheet and operate only in radiator mode, only in cooling mode or alternatively according to the two modes, a control module being configured to activate or not the power supply to each of the tubes depending on the hot or cold air needs of the vehicle.

According to a second configuration, the heat exchanger can comprise two sheets successively traversed by an air flow, a first sheet comprising the thermal device according to the preceding characteristics and a second sheet comprising a series of tubes arranged between connection blocks and inside which circulates a refrigerant capable of exchanging cold temperatures with the air flow.

The second sheet can thus be an evaporator of an air conditioning loop, the heat exchanger being controlled to operate according to the conditions as a radiator or evaporator. More specifically, a control module is then configured to, on the one hand, allow or not the passage of refrigerant fluid in the tubes of each of the layers and, on the other hand, to allow or not the power supply in the heating tubes of the first tablecloth, depending on the desired operating mode.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and several examples of embodiment given by way of indication and not limitation with reference to the appended schematic drawings on the other. part, on which:

is a general perspective view of a thermal device according to a first embodiment of the invention, comprising an exchange surface with at least one radiating element and a tube;

is a schematic view of the thermal device of FIG. 1 showing a connection block and an additional connection block arranged on either side of the heat exchange surface in which is arranged a series of tubes and radiating elements arranged between the tubing;

is a schematic view of an internal space of the connection block of Figure 2 in which is housed one end of at least one tube;

is a schematic cross-sectional view of a series of tubes of Figure 2;

is a schematic view of a PTC-effect polymer-based heater strip;

is a schematic view of the thermal device according to a second embodiment of the invention;

is a schematic view of a cross section of a series of tubes equipping a thermal device according to a third embodiment of the invention;

is a schematic view of a cross section of a series of tubes equipping a thermal device according to a fourth embodiment of the invention.

The features, variants and different embodiments of the invention may be associated with each other, in various combinations, insofar as they are not incompatible or exclusive of each other. It is possible in particular to imagine variants of the invention comprising only a selection of characteristics described below in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from to the state of the prior art.

FIG. 1 illustrates a thermal device 1, consisting of a heat exchanger intended to be installed in a ventilation, heating and/or air conditioning installation of a vehicle, for example an automobile, which may in particular be a hybrid or electric vehicle.

The thermal device 1 is configured to be traversed by a fluid, for example air, at the level of an exchange surface 2 configured to allow the exchange of calories and/or cold temperatures between the thermal device 1 and the fluid crossing.

The exchange surface 2 is made up of a series of tubes 4 and radiant elements 6, the tubes 4 forming elements capable of generating calories and/or cold temperatures to be supplied to the fluid passing through and the radiating elements 6 being formed by fins making it possible to diffuse said heat and/or cold more easily by increasing the exchange surface 2 with the fluid passing through it. The radiant elements 6 can then, for example, be brazed onto the tubes, this fixing offering an optimum connection of the radiant elements 6 with the tubes 4.

The tubes 4 are arranged parallel to each other extending in a main direction of elongation along a vertical direction V of the thermal device 1. Each of the tubes 4 is spaced from the neighboring tubes 4 by a first non-zero distance D1. In this way, a space is made between each of the tubes 4 in order to allow the passage of the fluid through the exchange surface 2 in a transverse direction of passage, substantially perpendicular to the plane mainly defined by the exchange surface 2, the first distance D1 being measured along this plane mainly defined by the exchange surface 2 between two adjacent tubes 4.

Each of the tubes 4 comprises a first connection end 8 and a second connection end 10, opposite along the vertical direction V of the thermal device 1 to the first connection end 8. The first connection end 8 and the second connection end 10 vertically delimit the exchange surface 2 and each of the connection ends 8, 10 is here secured to a connection block. In the example illustrated in Figure 1, the thermal device 1 comprises a connection block 12 arranged at the first connection end 8 of the tubes 4 and an additional connection block 14 arranged at the second connection end 10 of the tubes 4.

According to the invention, the connection block 12 and the additional connection block 14 are presented as boxes comprising an outer wall 16 extending mainly in a longitudinal direction L of the thermal device 1, perpendicular to the vertical direction V of the thermal device 1, and they respectively comprise an internal space 18 and an additional internal space 20 as shown in Figure 2.

Arbitrarily, an upper face 22 and a lower face 24 of the outer wall 16 of the connection block 12 are defined, the lower face 24 being the face facing the volume of the heat exchange surface 2, the upper face 22 being the face opposite the lower face 24 in the vertical direction V of the thermal device 1.

The particular configuration of the connection blocks 12, 14 as well as the structure and the arrangement of the tubes 4 will now be described in more detail according to a first embodiment of the invention with reference to Figures 2 to 5.

According to the invention, at least one of the connection blocks 12, 14 of the thermal device 1 is configured to accommodate an internal electrical network 28 and a supply channel 30 of refrigerant fluid. In the illustrated example visible in Figure 2, the connection block 12 has this particular structure, that is to say allowing it to accommodate the internal electrical network 28 and the supply channel 30 in refrigerant fluid, while the additional connection block 14 is configured to house only a collecting chamber 31 of the refrigerant fluid.

More specifically, and as can be seen in Figure 3, the connection block 12 has an electrical chamber 32, configured to house electrical power supply means, and a cooling chamber 34, configured to be traversed by fluid refrigerant. The two chambers extend mainly, within the connection block 12, along the longitudinal direction L of the thermal device 1. These two chambers are according to the invention arranged one beside the other being separated from one another. on the other by an internal partition 36. This internal partition 36 provides a sealed demarcation between the two chambers.

In the example illustrated, said electrical 32 and cooling chambers 34 are superimposed on one another in the vertical direction V of the thermal device 1. In this illustrated example, the electrical chamber 32 constitutes the chamber delimited vertically by the lower face 24 and the internal partition 36, while the refrigerating chamber 34 is delimited vertically by the internal partition 36 and the upper face 22. It should be noted that other arrangements would be possible without departing from the context of the invention, and in particular a side-by-side arrangement of the chambers in the transverse direction of the thermal device, with in this case an internal partition which would be vertical rather than horizontal. Also, it is considered that it is possible to invert the arrangement of the refrigerating 34 and electric 32 chambers, that is to say inverting their superimposed configuration in the vertical direction V of the thermal device 1.

The connection block 12 has a first longitudinal end 38 and a second longitudinal end 40, opposite the first longitudinal end 38 along the longitudinal direction L of the thermal device 1. The refrigerating chamber 34 and the electrical chamber 32 extend longitudinally in the internal space 18 of the connection block 12, from the first longitudinal end 38 to the second longitudinal end 40. A fluid inlet 42 is then arranged in the longitudinal extension of the cooling chamber 34 at the level of the first longitudinal end 38 of the connection block 12 as shown in Figure 3 or at the level of the second longitudinal end 40 of the connection block 12 as shown in Figure 2.

In the same way, an electrical inlet 44 is arranged in the longitudinal extension of the electrical chamber 32 at the level of the first longitudinal end 38 of the connection block 12 as shown in Figures 2 and 3, but it is understood that the electrical inlet 44 can also be arranged at the level of the second longitudinal end 40 of the connection block 12.

The fluid inlet 42 notably allows the cooling fluid to be supplied to the cooling chamber 34, the cooling fluid being able, for example, to come from an internal reservoir (not visible) of the motor vehicle. The electrical inlet 44 allows the passage of electrical cables for example, making it possible to connect the internal electrical network 28 housed in the electrical chamber 32, to an electrical power source of the motor vehicle, which may for example consist of a battery.

The additional connection block 14 arranged at the second connection end 10 of the tubes 4 is in this example devoid of an electrical chamber and only comprises in its additional internal space 20 a collecting chamber 31 of refrigerant fluid.

It is understood from the above that the connection block 12 and the additional connection block 14 as they have just been described constitute manifolds. More particularly, the connection block 12 constitutes a header box, both from the point of view of electrical distribution and of the distribution of refrigerant fluid, in the sense that they make it possible to collect electrical energy from a system of power supply to the vehicle and the refrigerant from a vehicle distribution system, and to redistribute them in the tubes 4.

According to the invention, the tubes 4 are hollow and therefore allow, on the one hand, the circulation within them of the refrigerant fluid, and, on the other hand, the presence within them of at least one heating element 51 with PTC effect. .

They each have an internal face 46 and an external face 48, the external face 48 being the face in contact with the fluid passing through the exchange surface 2 and the internal face 46 being the face opposite the external face 48 and defining a cavity internal 50 of the tube 4. It should be noted that the tubes here have a substantially oblong section, without this being limiting of the invention.

The PTC-effect heating element 51 may for example be a heating tape, as can be seen in particular in FIG. 5, but it should be considered that the PTC-effect heating element 51 may take any other form, as long as this allows it to be integrated into the tubes 4 and to provide adequate thermal power to the thermal device 1.

The PTC effect heating element 51, as illustrated in FIG. 5, may be composed of at least one metallic conductor 52, here in the example illustrated two parallel metallic conductors 52, each metallic conductor 52 being embedded in a semi-crystalline polymer matrix 54 doped with conductive particles, preferably carbon black, so as to constitute a positive temperature coefficient (PTC) thermistor.

The metal conductors 52 are for example copper-nickel wires, forming the heating part of the heating element 51 with PTC effect and whose end emerging from the heating element 51 is thus connected to the internal electrical network 28 of the connection block 12 or additional connection block 14.

The assembly is also provided with at least one layer of dielectric material 56 surrounding the polymer matrix 54 and which aims to electrically insulate the assembly formed by the metal conductors 52 and the polymer matrix 54 while allowing the transfer of heat. released by the operation of this set.

In the example illustrated, the layer of electrically insulating material, or else layer of dielectric material 56, consists of a specific insulating sheath arranged around the polymer matrix 54 and forming part of the flexible strip. As a variant, the casing of tube 4 can be anodized, so that it is tube 4 itself which performs the dielectric function to prevent the transmission of electric current to the radiating elements in particular.

Furthermore, the PTC effect heating element 51 is provided with a protection element 58 which protects the layer of dielectric material 56. This protection element 58 can be directly formed by the envelope of the tube 4, or else be made by a specific protective sheath, or alternatively, as illustrated in FIG. 5, be achieved by oversizing the layer of dielectric material 56 so that the same layer forms the electrical insulation and the mechanical protection.

It should be noted that in Figure 5, the layer of dielectric material 56 and the protective element 58 have been illustrated cut to reveal a part of the polymer matrix 54 and the end of the metal conductors 52, it being noted that this layer of dielectric material 56 and this protective element 58 extend over the length of the heating element 51 so as to completely cover the polymer matrix 54.

In order to be able to accommodate the at least one heating element 51 and allow the circulation of the refrigerant fluid in its internal cavity 50, at least one of the internal cavities 50 of the tubes 4 of the heat exchange surface 2 comprises at least one heating channel 60 and a cooling channel 62. According to the first embodiment, the set of tubes 4 of the heat exchange surface 2 comprises an internal cavity 50 with a heating channel 60 and a cooling channel 62 and it is then understood that the characteristics of the tube 4 which will be described below apply to all of the tubes 4 of the exchange surface 2 of the thermal device 1 according to the first embodiment of the invention.

The heating channel 60 is arranged in such a way that it houses the PTC effect heating element 51 mentioned above, which extends in the tube 4 from the first connection end 8 to the second connection end 10. equivalently, the coolant channel 62 is arranged in such a way that it allows the coolant fluid to pass through the tube 4 from the first connection end 8 to the second connection end 10.

As referenced in Figure 4, the tube 4 comprises a first transverse end 64 and a second transverse end 66, opposite the first transverse end 64 in a transverse direction T of the thermal device 1, the transverse direction T being perpendicular to the main direction of elongation of the tubes 4 and to the longitudinal direction L of the thermal device 1. It should be noted that this transverse direction T also corresponds to the direction of passage of the fluid passing through the exchange surface. The first transverse end 64 you tube corresponds to the inlet end of the fluid passing through the heat exchange surface 2, that is to say the side by which the fluid enters the thermal device, while the second transverse end 66 corresponds to the outlet end of the fluid passing through the heat exchange surface 2, that is to say the side by which the fluid leaves the thermal device. The cooling channel 62 is then placed in the internal cavity 50 at the first transverse end 64 of the tube 4 while the heating channel 60 is placed in the internal cavity 50 at the level of the second transverse end 66 of the tube 4, so that the heating channel 60 extends on the side where the air flow exits through the exchange surface 2.

The first connection end 8 of the tube 4 and the corresponding connection block 12 are formed such that the heating channel 60 is connected to the electrical chamber 32, and the cooling channel 62 is connected to the cooling chamber 34. At this end, and according to the structural characteristics of the connection block 12 mentioned above, with chambers superimposed vertically one above the other, it is understood that the cooling channel 62 will extend into the internal space 18 of the block connection 12 along the vertical direction V of the thermal device 1, over a distance greater than that of the heating channel 60.

The connection block 12 has two openings, one formed on its external wall 16 and the other on its internal partition 36. More precisely, a first opening 68 is formed on the lower face 24 of the external wall 16 in opposite the first connection end 8 of the tube 4, and a second opening 70 is provided opposite the first connection end 8 on the internal partition 36.

A second distance D2 is defined as being the width of the tube, corresponding to the distance separating the first transverse end 64 and the second transverse end 66 of the tube 4, measured along a straight line parallel to the transverse direction T of the thermal device 1 A third distance D3 is then defined as being the width of the heating channel 60, corresponding to the distance along which the heating channel 60 extends in the tube 4 from the second transverse end 66 of the tube 4, measured along a straight line parallel to the transverse direction T of the thermal device 1. In the same way, a fourth distance D4 is defined as being the width of the cooling channel 62, corresponding to the distance along which the cooling channel 62 extends in the tube 4 from the first transverse end 64 of tube 4, measured along a straight line parallel to the transverse direction T of the thermal device 1. In the example shown, the sum of the third distance D3 and the fourth distance D4 is equivalent to the second distance D2.

The first opening 68 made on the lower face 24 of the outer wall 16 of the connection block 12 is thus made in such a way that it allows the passage of the first connection end 8 of the tube 4 and therefore extends transversely over a fifth distance D5 measured along a straight line parallel to the transverse direction T of the thermal device 1, the fifth distance D5 being at least equal to the second distance D2 of the tube 4.

As mentioned above, the heating channel 60 must communicate with the electrical chamber 32 while the cooling channel 62 must communicate with the cooling chamber 34. Said cooling chambers 34 and electrical chambers 32 being superimposed on each other in the direction vertical V of the thermal device 1, a free end of the heating channel 72 and a free end of the cooling channel 74 are defined, both distinct, that is to say not communicating and formed at the first connection end 8, such as can be seen in figure 3.

The free end of the heating channel 72 opens into the electrical chamber 32, such that the free end of the heating channel 72 extends between the internal partition 36 and the lower face 24 of the external wall 16 of the connection block 12 This allows the passage of electrical cables coming from the electrical chamber 32 as far as the PTC effect heating element 51 by means of the free end of the heating channel 72. These electrical cables are adapted to be connected to the free ends of the conductors electrical 52.

The free end of the cooling channel 74 opens into the cooling chamber 34. It is then understood that the second opening 70 made in the internal partition 36 of the connection block 12 has a transverse dimension at least equal to the fourth distance D4, such that that it allows the passage of the free end of the coolant channel 74 by ensuring around the tube portion delimiting this end of the coolant channel a seal to the passage of coolant fluid. Said free end of the cooling channel 74 is therefore arranged between the internal partition 36 and the upper face 22 of the connection block 12, thus allowing the passage of the cooling fluid stored in the cooling chamber 34 of the connection block 12, towards the cooling channel 62 of the pipe 4.

A seal can for example be arranged between the second opening 70 and the free end of the cooling channel 74 in order to increase the seal between the cooling chamber 34 and the electrical chamber 32.

The coolant fluid entering the coolant channel 62 from the coolant chamber 34 travels through the coolant channel 62 of the tube 4, that is to say from the first connection end 8 to the second connection end 10 housed in the block of additional connection 14. More precisely, the coolant is collected in the collecting chamber 31 of the additional connection block 14 in order to be evacuated from the thermal device 1 by means of a fluid outlet provided at a longitudinal end of the additional connection 14, visible in particular in Figure 2.

A second embodiment will now be described in relation to FIG. 6. It should be considered that only the distinct characteristics of the first embodiment will be exposed. For the common characteristics, reference should be made to what has been previously described with reference to Figures 1 to 5.

In this embodiment, the additional connection block 14 comprises an additional internal electrical network 78, the PTC effect heating elements 51 of the heat exchange surface 2 being distributed in a first assembly 80 connected to the internal electrical network 28 of the connection block 12 and a second set 82 connected to the additional internal electrical network 78 of the additional connection block 14.

According to an example of the invention, the first set 80 of heating elements 51 with PTC effect can correspond to a first part of the series of tubes 4 and the second set 82 of heating elements 51 with PTC effect corresponds to a second part of the series of tubes 4 arranged in the longitudinal continuity of said first part.

It is then understood that the additional connection block 14 comprises a structure identical to the connection block 12, that is to say that it has an additional refrigerating chamber 84 and an additional electrical chamber 86 separated by an internal partition making each bedrooms. Furthermore, the second connection end 10 of the tubes is similar to their first connection ends 8, that is to say that they each comprise an additional free end of the heating channel 88 and an additional free end of the cooling channel 90 whose arrangement with the additional connection block 14 is such that it allows a differentiated connection between the additional electrical chamber and the first free ends of heating channels 72 on the one hand:! and the additional refrigerating chamber and the first free ends cooling channels 74 on the other hand.

An advantage of such a configuration of the thermal device 1 lies in particular in the fact that it allows independent control of the first set 80 of heating elements 51 with PTC effect and of the second set 82 of heating elements 51 with PTC effect, each assembly 80, 82 being connected to an internal electrical network of its own, allowing the electrical supply of one or the other of the assemblies independently or simultaneously. This configuration is therefore advantageous, for example, in the context of heating the passenger compartment of a motor vehicle, since it is then possible, for example, to heat the passenger space independently of the driver's space.

A third embodiment of the invention will now be described with FIG. 7. This embodiment is in particular a variant of the first embodiment of the invention and it is then understood that only the distinct characteristics will be mentioned in the following the detailed description. This third embodiment differs in particular in the configuration of the tubes.

In this third embodiment, at least one tube 4 of the exchange surface 2 comprises a plurality of cooling channels 62 and a plurality of heating channels 60. In the example illustrated, the tube 4 comprises four cooling channels 62 and three heating channels 60, but it is understood that the tube 4 can comprise more or less than one or the other of heating channels 60 and/or cooling channels 62. The heating channels 60 and the cooling channels 62 of the tube 4 are then arranged alternately in the internal cavity 50 of the tube 4, that is to say that a cooling channel 62 is separated from another cooling channel 62 of the tube 4 by the presence of a heating channel and that a heating channel 60 is separated from another heating channel 60 of the tube by the presence of a cooling channel.

It is then understood that the tube 4 has at its first connection end 8 an alternation of free end of cooling channels and free end of heating channels having the same characteristics as the free end of heating channel 72 and the free end of cooling channel 74 of the first embodiment. More specifically, the four free ends of the cooling channels open into the cooling chamber of the connection block while the three free ends of the heating channels open into the electrical chamber of the connection block, with the same vertical offset as previously mentioned.

The technical and structural characteristics of the tube as they have just been described apply for example to all the tubes 4 of the exchange surface of the thermal device 1. Similarly, it is possible to combine the third mode embodiment with the second embodiment of the invention without this combination departing from the scope of the invention.

A fourth embodiment will now be described in relation to FIG. 8, in which it is visible that this fourth embodiment is in accordance with the invention in that the tubes through which the refrigerant fluid passes comprise at least one heating element at PTC effect, this fourth embodiment differing from the above in that the tube is not compartmentalized so that the refrigerant liquid circulates throughout the tube and in that the PTC effect heating element is this time pressed against a face of the corresponding tube, whether this face is an external face of the tube as illustrated in FIG. 8 or an internal face.

Thus, in this embodiment, the internal cavity 50 of the tube 4 comprises only the coolant channel 62 through which the coolant liquid passes. The cooling channel 62 then extends over the second distance D2 of the tube 4 from the first transverse end 64 to the second transverse end 66.

The PTC effect heating element 51 has the form of a heating film 92 attached against a wall delimiting the tube, that is to say a sheet of heating material whose thickness is small compared to the thickness of the wall. of the tube. In the example illustrated, the heating film 92 is placed against the external face 48 of the tube 4.

The heating film 92 extends against one face of the tube 4, here the external face 48, over all or almost of the transverse dimension of the tube. AND it is configured to extend over the entire exchange surface, from the first connection end to the second connection end. On the other hand, it is understood that to allow a stepped connection as illustrated in the other embodiments, with a refrigerating chamber and an electrical chamber, it is appropriate that the heating film 92 extends only partially over the height, it that is to say the vertical dimension, of the wall of the tube so that its free end extends into the electrical chamber.

It follows from the above that, in this fourth embodiment, the first opening and the second opening both have a transverse distance at least equal to the second distance D2. The longitudinal dimension may vary slightly from the first opening to the second opening, to allow the heating film 92 to pass through the first opening with the tube when this heating film is as illustrated on the external face of the tube.

When the heating film 92 is placed against the external face 48 of the tube 4, the radiating elements cannot be brazed with the tubes 4 and these are then bonded with the tubes 4 and the heating film 92 of the exchange surface 2 .

According to another example not illustrated, the heating film 92 can be placed against the internal face 46 of the tubes 4, according to the same characteristics as when the heating film 92 is against the external face 48 of the tube 4. In this alternative, the radiating elements can be brazed with tubes 4.

Of course, the invention is not limited to the examples which have just been described and many adjustments can be made to these examples without departing from the scope of the invention.

The invention, as it has just been described, achieves the goal it had set itself, and makes it possible to propose a more ergonomic thermal device and having improved thermal capacities in particular by making it possible to heat and/or cooling a flow of air passing through the same thermal device. Variants not described here could be implemented without departing from the context of the invention, provided that, in accordance with the invention, they include at least a tube conforming to the aspect of the invention.

Claims (10)

Thermal device (1) comprising at least one heat exchange surface (2) and at least one connection block (12) which borders the heat exchange surface (2), the exchange surface (2) of heater comprising a series of tubes (4) parallel to each other and extending in a main direction of elongation of the thermal device (1), each tube (4) being connected to the connection block (12) and at least one of the tubes (4) being traversed by a refrigerant fluid, the thermal device (1) being characterized in that at least one of the tubes (4) traversed by the refrigerant fluid comprises at least one heating element (51) with PTC effect. Thermal device (1) according to the preceding claim, in which the connection block (12) is arranged to house at least one electrical network (28) and a supply channel (30) for refrigerant fluid. Thermal device (1) according to any one of Claims 1 to 2, in which at least one tube (4) defines an internal cavity (50), the internal cavity (50) providing at least one cooling channel (62) and at at least one heating channel (60), the cooling channel (62) allowing the circulation of the cooling fluid and the heating channel (60) housing the heating element (51). Thermal device (1) according to the preceding claim, in which the tube (4) comprises a first transverse end (64) and a second transverse end (66), opposite the first transverse end (64) in a transverse direction (T) perpendicular to the main direction of elongation of the tubes (4), the heating channel (60) being arranged at the first transverse end (64) of the tube (4). Thermal device (1) according to Claim 3 or 4, in which the internal cavity (50) of the at least one tube (4) comprises a plurality of cooling channels (62) and a plurality of heating channels (60), arranged so as to alternately in the internal cavity (50) of the tube (4). A thermal device (1) according to any preceding claim, wherein the PTC-effect heating element (51) comprises at least one metallic conductor (52) embedded in a PTC-effect polymer matrix (54). A thermal device (1) according to any one of claims 1 to 3, wherein the heating element (51) is a heating film (92) disposed against one side of the tube (46, 48). Thermal device (1) according to any one of the preceding claims, in which each of the tubes (4) of the exchange surface (2) is traversed by the refrigerant fluid and comprises the at least one heating element (51). Thermal device (1) according to the preceding claim, further comprising an additional connection block (14), such that the connection block (12) and the additional connection block (14) are positioned on either side of the exchange surface (2) and the heating elements (51) of the exchange surface (2) are divided into a first set (80) and a second set (82), the first set (80) being electrically connected to the connection block (12) and the second assembly (82) being electrically connected to the additional connection block (14). Heat exchanger composed of at least one sheet comprising the thermal device (1) according to the preceding claims.