Vehicle heat treatment system

Abstract

Title of the invention: Vehicle heat treatment system. The present invention relates to a heat treatment system (1) comprising an airflow circulation duct (6) (2), a heat transfer fluid circuit (20), a first heat exchanger (12) and a second heat exchanger (14) arranged successively in the circulation duct (6) and each connected to the heat transfer fluid circuit (20) by a fluid inlet (22, 22A, 22B) and a fluid outlet (24, 24A, 24B), at least one of the two heat exchangers (12, 14) being configured to alternately exhibit a cooling mode and a heating mode, this heat exchanger (12, 14) being configured to be traversed by the heat transfer fluid at a first inlet temperature in its cooling mode and at a second inlet temperature in its heating mode. Abstract figure: Figure 1

Description

Title of the invention: Thermal treatment system for a vehicle

[0001] The present invention relates to the field of ventilation, heating and / or air conditioning installations, and more particularly to such installations implemented in motor vehicles.

[0002] Motor vehicles are commonly equipped with a heat transfer fluid circuit used to heat or cool different areas or different components of the vehicle. It is particularly known to use these heat transfer fluid circuits to cool an electrical storage device such as a battery of a vehicle equipped with this circuit.

[0003] It is also known to use this heat transfer fluid circuit to thermally treat an air flow sent to the passenger compartment of the vehicle. Such thermal treatment makes it possible to send hot air or cold air, according to the user's wishes, to respectively increase or decrease the temperature of the passenger compartment of the vehicle.

[0004] In another use of the heat transfer fluid circuit, the air flow is intended to dehumidify the passenger compartment of the vehicle. The term "dehumidify" means the ability of the heat transfer fluid circuit to limit the presence of water in the air flow entering the passenger compartment of the vehicle. Indeed, when humid air from the passenger compartment comes into contact with a cold surface, the water contained in the air condenses and a film of water droplets is deposited on the cold surfaces of the passenger compartment of the vehicle, in particular on its windows. This film of water forms fog which obstructs the driver's visibility of the road or of his rearview mirrors, which represents a significant risk to the safety of the vehicle's occupants.

[0005] In order to address such problems, it is known from the prior art to propose ventilation, heating and / or air conditioning installations in which the air flow passes through a main heat exchanger of a substantial size, then, depending on the requirements, is directed by means of a mixing flap either towards a secondary heat exchanger, of reduced size compared to the main heat exchanger, or towards a bypass path of this secondary heat exchanger. In other words, at the outlet of the main heat exchanger, the mixing flap directs the air flow alternately towards the secondary heat exchanger or the bypass path thereof.The air flow is then cooled or heated by exchanging calories with a heat transfer fluid at a first temperature in the primary heat exchanger and, if necessary, cooled or heated again by exchanging calories with a heat transfer fluid at a second temperature in the secondary heat exchanger.

[0006] The present invention falls within this context by proposing a ventilation, heating and / or air conditioning installation in which the air flow passes through, whatever the needs within the vehicle, both a first heat exchanger and a second heat exchanger, both of reduced size compared to the main heat exchanger of the prior art. The presence of these smaller heat exchangers makes it possible to achieve savings, by more easily handling reduced air flow volumes, and by limiting the pressure losses resulting in the prior art from the presence of the mixing flap in particular. The exchangers of reduced size also make it possible to improve the homogeneity of the exchanges between the air flow and the heat transfer fluid circuit, the entire air flow being concentrated in the same zone of reduced size.

[0007] The main subject of the present invention is thus a thermal treatment system for a vehicle comprising a housing of a thermal installation intended to be traversed by a flow of air intended to be heated and / or cooled, comprising at least one duct for circulating the flow of air, the thermal treatment system further comprising a heat transfer fluid circuit.According to the invention, the heat treatment system comprises a first heat exchanger and a second heat exchanger arranged successively in the circulation duct, the first heat exchanger being closer to an inlet of the air flow in the circulation duct than the second heat exchanger, the heat exchangers each being connected to the heat transfer fluid circuit by a fluid inlet and a fluid outlet, at least one of the two heat exchangers being configured to alternately present at least one cooling mode and one heating mode, this heat exchanger being configured to be crossed by the heat transfer fluid at a first inlet temperature in its cooling mode and by the heat transfer fluid at a second inlet temperature in its heating mode.

[0008] The heat treatment system according to the invention is intended to equip thermal, hybrid or electric motor vehicles in particular for the purpose of heating, cooling and / or dehumidifying certain of their elements. The heat treatment system is thus intended to heat, cool or dehumidify an air flow coming from outside the vehicle before conducting it to a passenger compartment of this vehicle. The heat treatment system comprises a housing of a thermal installation, here a ventilation, heating and / or air conditioning installation, within which various elements of the heat treatment system are arranged. The housing comprises an air flow circulation duct, which is the portion of the housing through which the air flow is introduced into the heat treatment system.Within this circulation duct are arranged successively the first heat exchanger and the second heat exchanger. The . heat exchangers are arranged in series. It is understood that the air flow passes through the first heat exchanger before passing through the second heat exchanger, since the first heat exchanger is closer to an air flow inlet in the circulation duct than the second heat exchanger. The fact that the air flow passes through both heat exchangers ensures a total exchange surface area as large as that of the main heat exchanger of the prior art.

[0009] In addition to the air flow, the two heat exchangers are capable of being traversed by a heat transfer fluid of a heat transfer fluid circuit. This heat transfer fluid is conveyed to each of the heat exchangers by a fluid inlet, i.e. a first fluid inlet for the second heat exchanger and a second fluid inlet for the first exchanger, and it is discharged by means of their respective fluid outlets, i.e. a first fluid outlet for the second heat exchanger and a second fluid outlet for the first heat exchanger.

[0010] The first heat exchanger and the second heat exchanger have a reduced size, and consequently a reduced footprint compared to the main heat exchanger of the prior art. Due to this reduced size of the heat exchangers, the heat exchanges between the air flow and the heat transfer fluid take place over a smaller surface area and therefore in a more homogeneous manner. Furthermore, it is possible to more easily control the heat treatment system to treat small air flows, which allows savings to be made. The production of the heat treatment system is simplified because it is no longer necessary to manufacture a mixing flap or to provide a bypass route.

[0011] At least one of the heat exchangers is configured to alternate between at least one cooling mode, in which the heat transfer fluid enters this heat exchanger at a first temperature, and a heating mode, in which the heat transfer fluid enters the heat exchanger at a second, higher temperature. This makes it possible to have a heat transfer fluid at substantially the same temperature whether for heating or cooling the air flow depending on the chosen configuration of the second heat exchanger.

[0012] According to an optional characteristic of the invention, the first inlet temperature and the second inlet temperature have a difference of between 20 and 40°C.

[0013] At its first inlet temperature, the heat transfer fluid allows the air flow to be cooled, while at its second inlet temperature the heat transfer fluid heats it.

[0014] According to an optional characteristic of the invention, the first heat exchanger and the second heat exchanger extend over the entire passage section of the circulation duct.

[0015] The passage section of the circulation duct is delimited by walls which limit said circulation duct. It is understood here that there is no bypass route for either of the heat exchangers within the circulation duct; thus, the air flow circulating in the circulation duct necessarily passes through both the first heat exchanger and the second heat exchanger.

[0016] According to an optional feature of the invention, both the first heat exchanger and the second heat exchanger are configured to have at least the cooling mode and the heating mode.

[0017] In other words, the first heat exchanger is configured to have the cooling mode and the heating mode and the second heat exchanger is configured to have the cooling mode and the heating mode.

[0018] According to an optional characteristic of the invention, the first heat exchanger and / or the second heat exchanger are configured to have an inactive state.

[0019] The inactive state corresponds to a state in which there is no exchange of calories between the air flow and the heat transfer fluid. In this inactive state, the air flow passes through the heat exchanger without being heated or cooled by the heat transfer fluid, for example because the latter does not circulate within the heat exchanger. The inactive state of the heat exchanger is distinguished from its active state, which covers both the cooling mode and the heating mode. The heat exchanger then has three alternative configurations: the inactive state, the cooling mode and the heating mode.

[0020] According to an optional characteristic of the invention, one of the heat exchangers is in its cooling mode or in its heating mode when the other is in its inactive mode.

[0021] Such configurations correspond to an operating mode of the heat treatment system used when the cooling or heating requirements are limited within the vehicle. When the cooling or heating permitted by only one of the heat exchangers is sufficient to provide an air flow at the desired temperature within the passenger compartment, the other heat exchanger is in its inactive mode so as to achieve energy savings. The heat treatment system according to the invention is then optimized for small cooling or heating capacities, where the main heat exchanger of the prior art is only optimized for large powers.

[0022] According to an optional feature of the invention, the first heat exchanger and the second heat exchanger are both in the cooling mode or both in the heating mode.

[0023] These configurations correspond to a mode of operation of the heat treatment system which requires significant cooling or heating of the air flow, especially in summer and winter. The joint implementation of the first heat exchanger and the second heat exchanger in either their cooling or heating modes allows for optimal cooling or heating of the air flow in a short time, respectively. For example, if both heat exchangers are in the cooling mode, the air flow will be pre-cooled as it passes through the first heat exchanger, and then cooled again as it passes through the second heat exchanger.

[0024] According to an optional characteristic of the invention, the first heat exchanger is in its cooling mode when the second heat exchanger is in its heating mode.

[0025] This configuration corresponds to a dehumidification mode, that is to say an operating mode of the heat treatment system which makes it possible to dehumidify the air flow. In this dehumidification mode, it is necessary to cool the air flow before heating it. Passing through the first heat exchanger in its cooling mode makes it possible to condense the humidity present in the air flow, and passing through the second heat exchanger makes it possible to bring this air flow to the desired temperature within the passenger compartment.

[0026] According to an optional characteristic of the invention, the fluid inlet and the fluid outlet are arranged on the same side of their respective heat exchangers.

[0027] In other words, the heat transfer fluid inlet and outlet of the first heat exchanger are arranged on the same side of this first heat exchanger, and the heat transfer fluid inlet and outlet of the second heat exchanger are arranged on the same side of this second heat exchanger. The heat transfer fluid inlets and outlets are all arranged on the same side of the air flow circulation duct, which limits the space constraints.

[0028] According to an optional characteristic of the invention, the fluid outlet of the second heat exchanger is fluidically connected to the fluid inlet of the first heat exchanger.

[0029] In other words, a pipe connects the fluid outlet of the second heat exchanger to the fluid inlet of the first heat exchanger. Thus, the heat transfer fluid leaving the second heat exchanger is directed to the first heat exchanger. A single heat transfer fluid circuit supplies both the first heat exchanger and the second heat exchanger.

[0030] According to an optional characteristic of the invention, each of the heat exchangers is configured for a “U”-shaped circulation of the heat transfer fluid between its heat transfer fluid inlet and its heat transfer fluid outlet.

[0031] According to an optional characteristic of the invention, the heat treatment system is configured so that the first heat exchanger is crossed by the air flow before the second heat exchanger, and the second heat exchanger is crossed by the heat transfer fluid before the first heat exchanger.

[0032] Due to such countercurrent circulation of the air flow and the heat transfer fluid, the heat exchanges are optimized within the heat treatment system by limiting excessively large temperature differences between the air flow and the heat transfer fluid. Here, the term "countercurrent circulation" means that the air flow circulates first in the heat exchanger in which the heat transfer fluid circulates second. The air flow first passes through the first heat exchanger and then the second heat exchanger, and conversely the heat transfer fluid circulates first in the second heat exchanger and then in the first heat exchanger.For example, when both heat exchangers are in their cooling mode, the airflow to be cooled is hotter upon entering the first heat exchanger than the second heat exchanger since it has not yet exchanged calories with the heat transfer fluid, while the heat transfer fluid is colder upon entering the second heat exchanger than the first heat exchanger since it has not yet exchanged calories to cool the airflow. Conversely, the airflow passing through the second heat exchanger has already been partially cooled in the first heat exchanger, and similarly the heat transfer fluid circulating in the first heat exchanger has already been reheated when it has passed through the second heat exchanger.As a result, in the first heat exchanger, the temperature difference between the air flow and the heat transfer fluid is less than if the air flow and the heat transfer fluid both passed through the same heat exchanger first. Subcooling or preheating is thus achieved within the first heat exchanger, the heat transfer fluid already giving up or gaining calories there, then efficient cooling or heating is carried out in the second heat exchanger where the heat transfer fluid allows the air flow to be brought to the desired temperature. The heat exchanges are therefore limited, which allows savings to be made, in particular by using a heat transfer fluid at a lower temperature than if the air flow and the heat transfer fluid both passed through the same heat exchanger first.

[0033] According to an optional characteristic of the invention, the heat treatment system comprises a system for controlling the mode used by at least the first heat exchanger.

[0034] The control system makes it possible to control the transition from one mode to another. In particular, it is possible to control the time taken to transition from one mode to another. This is particularly useful when the heat treatment system is operating in its dehumidification mode and it is necessary to observe a latency period to ensure the absence of moisture in the first heat exchanger beforehand. to the implementation of its heating mode. The control system is thus configured to prevent an immediate switch of the first heat exchanger from its cooling mode to its heating mode.

[0035] According to an optional characteristic of the invention, the control system comprises a humidity or temperature sensor.

[0036] The humidity or temperature sensor is in particular configured to detect the presence of water within the first heat exchanger. It comprises, for example, a PTC effect resistor.

[0037] The invention further relates to a method of using a heat treatment system as mentioned above, during which the heat transfer fluid is circulated in one and / or the other of the heat exchangers at a given temperature.

[0038] The heat transfer fluid is supplied to the heat exchanger at the first inlet temperature when it is operating in its cooling mode, and it is supplied at the second inlet temperature when the heat exchanger is in its heating mode.

[0039] According to an optional characteristic of the invention, during the method of use, the heat transfer fluid is circulated successively in the second heat exchanger then in the first heat exchanger.

[0040] Such circulation of the heat transfer fluid makes it possible to obtain a counter-current with the air flow which circulates first in the first heat exchanger then in the second heat exchanger.

[0041] According to an optional characteristic of the invention, the method of use comprises a dehumidification step during which the first heat exchanger is operated simultaneously in cooling mode and the second heat exchanger in heating mode.

[0042] This makes it possible to get rid of the humidity present in the air flow by condensing it within the first heat exchanger, then to reheat the now dry air flow to the desired temperature within the second heat exchanger.

[0043] According to an optional characteristic of the invention, during the method of use following the dehumidification step the control system prevents the use of the heating mode of the first heat exchanger for a predetermined duration.

[0044] This predetermined duration corresponds to the time necessary to ensure the absence of water retention within the first heat exchanger, the latter having been wetted during the condensation operation of the air flow during the dehumidification step.

[0045] According to an optional characteristic of the invention, the use of the heating mode of the first heat exchanger is prevented as long as the sensor humidity or temperature sensor detects humidity or temperature above a predetermined threshold value in the vicinity of the first heat exchanger.

[0046] It is necessary to operate such a latency time, namely the predetermined duration, in order not to operate the first heat exchanger in heating mode when it is still humid, which would risk damaging it. The humidity or temperature value taken from within the heat exchanger is compared to a predetermined threshold value, or reference value, and the implementation of the heating mode of the first heat exchanger is impossible as long as the taken value is not below the threshold value.

[0047] According to an optional characteristic of the invention, the first heat exchanger is in its inactive state for the predetermined duration.

[0048] In this inactive state, the first heat exchanger is not crossed by the heat transfer fluid, which limits the risks of damage.

[0049] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and examples of embodiment given for informational and non-limiting purposes with reference to the appended drawings on the other hand, in which:

[0050] [Fig.l] schematically illustrates a heat treatment system in a first mode of operation, in which a first heat exchanger is in an active state and a second heat exchanger is in an inactive state;

[0051] [Fig.2] illustrates, schematically, the heat treatment system of [Fig.l] in a second mode of operation, in which the first heat exchanger and the second heat exchanger are in the same active state;

[0052] [Fig.3] schematically illustrates the heat treatment system in a third mode of operation, in which the first heat exchanger and the second heat exchanger are in different active states.

[0053] The features, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0054] In the figures, the elements common to several figures retain the same reference.

[0055] In the detailed description which follows, the term “heat transfer fluid” can refer to any cooling, refrigerant, thermal regulation fluid, di electric or two-phase, since this fluid, liquid or gaseous, has the effect of cooling or heating a flow of air.

[0056] Figures 1 to 3 thus illustrate, schematically, a heat treatment system 1 according to the invention. This heat treatment system 1 is part of a thermal installation such as a ventilation, heating and / or air conditioning installation. The thermal installation comprising the heat treatment system 1 is intended to be integrated within a motor vehicle, where it is dedicated, among other things, to regulating a temperature of a passenger compartment. For this purpose, the thermal installation and its heat treatment system 1 are configured to heat, cool and / or dehumidify an air flow 2 coming from outside the vehicle, represented in the figures by thick arrows. The air flow 2 is thus intended to be heated, cooled or even dehumidified, as required, before being sent to a passenger compartment of the vehicle.

[0057] The thermal installation comprises a housing 4 within which various elements of the heat treatment system 1 are housed. The housing 4 has a circulation duct 6 within which the air flow 2 circulates. More particularly, the circulation duct 6 constitutes the entry path of the air flow 2 into the heat treatment system 1. This circulation duct 6 is delimited by a first wall 8 and by a second wall 10, which are substantially parallel. The circulation duct 6 is further delimited by a bottom wall and a ceiling wall, not illustrated here, which connect the first wall 8 and the second wall 10 in pairs. The first wall 8, the second wall 10, the bottom wall and the ceiling wall delimit between them a passage section of the circulation duct 6.

[0058] The heat treatment system 1 comprises a first heat exchanger 12 and a second heat exchanger 14 of substantially equivalent sizes. The first heat exchanger 12 and the second heat exchanger 14 are both arranged in the circulation duct 6. More precisely and as can be seen in the figures, the two heat exchangers 12, 14 are arranged successively in the circulation duct 6 on the passage of the air flow 2, the first heat exchanger 12 being penetrated by this air flow 2 before the second heat exchanger 14.

[0059] The first heat exchanger 12 and the second heat exchanger 14 each comprise an inlet face 16 through which the air flow 2 enters them and an outlet face 18 through which the air flow 2 leaves them. The inlet and outlet faces 16, 18 of the heat exchangers 12, 14 extend from the first wall 8 to the second wall 10, and more generally from a given wall to the opposite wall. As a result, each of the first heat exchanger 12 and the second heat exchanger 14 extends over the entire passage section of the circulation duct 6 delimited by its walls 8, 10; in other words, the arrangement of the heat exchangers 12, 14 does not allow any bifurcation or bypass for the air flow 2, which therefore necessarily passes through both of them.

[0060] The heat treatment system 1 comprises a heat transfer fluid circuit 20, which is partially illustrated in the figures by thin arrows. Within the heat transfer fluid circuit 20 circulates a heat transfer fluid, which is, depending on the operating mode of the heat treatment system 1, a heat transfer fluid intended to cool the air flow 2 or to heat it. It is understood that when the heat transfer fluid is intended to cool the air flow 2 it has a temperature lower than this air flow 2, and conversely when the heat transfer fluid is intended to heat it it has a temperature higher than it.

[0061] The heat transfer fluid circulates either within the first heat exchanger 12, or within the second heat exchanger 14, or both within the first heat exchanger 12 and the second heat exchanger 14, according to operating modes which will be detailed later. The heat transfer fluid circuit 20 comprises for each heat exchanger 12, 14 a fluid inlet 22 and a fluid outlet 24. The heat transfer fluid circuit 20 more particularly has a first fluid inlet 22A and a first fluid outlet 22B arranged on the second heat exchanger 14, as well as a second fluid inlet 22B and a second fluid outlet 24B arranged on the first heat exchanger 12.The fluid inlets 22 constitute an entry point for the heat transfer fluid into their respective heat exchangers 12, 14, and the fluid outlets 24 are points of these heat exchangers 12, 14 through which the heat transfer fluid is discharged therefrom. In certain embodiments and as will be described subsequently, the first fluid outlet 24A of the second heat exchanger 14 is fluidically and directly connected to the second fluid inlet 22B of the first heat exchanger 12. Such a connection between the first fluid outlet 24A of the second heat exchanger 14 and the second fluid inlet 22B of the first heat exchanger 12 is for example made by means of a pipe 26 connected at one of its ends to the first fluid outlet 24A and at the other of its ends to the second fluid inlet 22B.For these embodiments, the heat transfer fluid circulates initially in the second heat exchanger 14 and then in a second stage in the first heat exchanger 12. The circulation of the heat transfer fluid then takes place counter-currently to the circulation of the air flow 2, in that on the contrary the latter circulates in the first heat exchanger 12 before passing through the second heat exchanger 14.

[0062] As mentioned above, the heat transfer fluid circulates within one or other of the heat exchangers 12, 14 according to a “U” circulation. To do this, on the second heat exchanger 14 the first fluid inlet 22A and the first fluid outlet 24A are arranged on the same side, and similarly on the first heat exchanger 12 the second fluid inlet 22B and the second fluid outlet 24B are arranged on the same side. As illustrated in the figures, the first fluid inlet 22A, the first fluid outlet 24A, the second fluid inlet 22B and the second fluid outlet 24B are all arranged on the same side of the circulation duct 6, here along its second wall 10, so as to facilitate the connection of these fluid inlets and outlets 22, 24 to the rest of the heat transfer fluid circuit 20.

[0063] In the absence of circulation of heat transfer fluid, the first heat exchanger 12 and the second heat exchanger 14 are in an inactive state, in which they do not exchange calories with the air flow 2. In this inactive state, the air flow 2 passes through the heat exchangers but is neither cooled nor actively heated by these heat exchangers 12, 14.

[0064] On the contrary, when the heat transfer fluid circulates within the heat exchangers 12, 14 in order to modify a temperature of the air flow 2, these heat exchangers 12, 14 are in an active state. This active state is either a cooling mode or a heating mode.

[0065] According to the invention, at least one of the first heat exchanger 12 and the second heat exchanger 14 is configured to alternately present at least one cooling mode and one heating mode. In other words, the same heat exchanger 12, 14 is configured to both cool and heat the air flow, alternately. Here, the term "alternately" or "alternately" means that a given heat exchanger 12, 14 is capable, depending on the mode used, of cooling or heating the air flow 2. Thus, at certain times, the heat exchanger 12, 14 operates according to the cooling mode, and at certain other times, it operates according to the heating mode.

[0066] The cooling mode and the heating mode are distinguished in particular by the inlet temperature of the heat transfer fluid when it arrives in the heat exchanger 12, 14, that is to say at the moment when it passes through the fluid inlet 22. More precisely, in the heating mode the heat exchanger 12, 14 receives the heat transfer fluid at a first inlet temperature, while in its cooling mode the heat exchanger 12, 14 receives the heat transfer fluid at a second inlet temperature. The inlet temperature at which the heat transfer fluid enters the heat exchanger 12, 14 is for example between 0°C and 15°C for the cooling mode and between 30°C and 80°C in the heating mode. Generally, there is a temperature difference between the first inlet temperature of the cooling mode and the second inlet temperature of the heating mode of at least 20°C. The first inlet temperature is thus adapted to cool the air flow 2 while the second inlet temperature is adapted to heat this air flow 2.

[0067] In some embodiments, both the first heat exchanger 12 and the second heat exchanger 14 are configured to alternately exhibit the cooling mode and the heating mode. Different operating modes of the thermal treatment system 1, in which each of the heat exchangers 12, 14 is either in its inactive state or in an active state among the cooling mode and the heating mode, will now be detailed in relation to FIGS. 1 to 3. In these figures, in the inactive state the heat exchanger 12, 14 is represented in the form of a solid white rectangle, while the heat exchanger 12, 14 in its active state takes the form of a hatched rectangle.

[0068] In [Fig. 1], which corresponds to a first mode of operation of the heat treatment system 1, the first heat exchanger 12 is in the inactive state and the second heat exchanger 14 is in the active state. The first heat exchanger 12 is not crossed by the heat transfer fluid. On the contrary, heat transfer fluid circulating within the heat transfer fluid circuit 20 is conveyed to the second heat exchanger 14 via the first fluid inlet 22A, where it exchanges calories with the air flow 2 before being evacuated via the first fluid outlet 24A. If the air flow 2 is intended to be cooled, the heat transfer fluid is at its first inlet temperature at the first fluid inlet 22A and the second heat exchanger 14 is then in its cooling mode.Conversely, if the air flow 2 is to be heated, the heat transfer fluid is at its second inlet temperature at the first fluid inlet 22A and the second heat exchanger 14 is in its heating mode.

[0069] Although as illustrated in [Fig. 1] it is the first heat exchanger 12 which is in the inactive state and the second heat exchanger 14 which is in the active state, one could alternatively and without departing from the scope of the invention envisage an embodiment in which the first heat exchanger 12 would be in the active state and the second heat exchanger 14 would be in the inactive state.

[0070] It is understood that the first mode of operation of the heat treatment system 1 covers both a variant in which the air flow 2 is cooled, namely when the one of the two heat exchangers 12, 14 which is in its active state is in its cooling mode, and a variant in which the air flow 2 is reheated, i.e. when the heat exchanger 12, 14 which is in the active state is in its heating mode. The first mode of operation of the heat treatment system 1 is used in the event of low cooling or heating requirements of the air flow 2.

[0071] In [Fig. 2], both the first heat exchanger 12 and the second heat exchanger 14 are in their active state. More particularly, in this [Fig. 2] which illustrates the second mode of operation of the heat treatment system 1, both heat exchangers 12, 14 are in the same active state; either both heat exchangers 12, 14 are in the cooling mode, or both heat exchangers 12, 14 are in the heating mode.

[0072] In this second mode of operation of the heat treatment system 1, the heat transfer fluid circulating in the heat transfer fluid circuit 20 is conveyed to the second heat exchanger 14 via the first fluid inlet 22A, and it exchanges calories with the air flow 2 prior to its evacuation from the second heat exchanger 14 via the first fluid outlet 24A. The heat transfer fluid then circulates in the pipe 26 through which it is conveyed to the first heat exchanger 12 which it enters via the second fluid outlet 22B and within which it again exchanges calories with the air flow 2. The heat transfer fluid is then evacuated from the first exchanger 12 through the second fluid outlet 24B. In this second embodiment, the same heat transfer fluid therefore passes through both the first and second heat exchangers 12, 14.When both heat exchangers 12, 14 are in the cooling mode, the heat transfer fluid enters the second heat exchanger 14 at the first inlet temperature. On the contrary, when both heat exchangers 12, 14 are in the heating mode, the heat transfer fluid enters the second heat exchanger 14 at the second inlet temperature. It is understood from the above that the second operating mode of the heat treatment system 1 covers on the one hand a variant in which the air flow 2 is cooled, namely when both heat exchangers 12, 14 are in the cooling mode, and on the other hand a variant in which the air flow 2 is heated, i.e. when both heat exchangers 12, 14 are in the heating mode. The second operating mode of the heat treatment system 1 is used when the cooling or heating requirements of the air flow 2 are significant..

[0073] [Fig. 3] shows a third mode of operation of the heat treatment system 1, in which the first heat exchanger 12 and the second heat exchanger 14 are in their active state; more particularly, the first heat exchanger 12 is in the cooling mode and simultaneously the second heat exchanger 14 is in the heating mode. This third mode of operation corresponds to a dehumidification mode of the air flow 2, by which the air flow 2 is freed from its humidity by condensation in the first heat exchanger 12 and then is reheated in the second heat exchanger 14 before being supplied to the passenger compartment of the vehicle.

[0074] In the dehumidification mode, the heat transfer fluid enters the second heat exchanger 14 at the first fluid inlet 22A at the second inlet temperature, and concomitantly it enters the first heat exchanger 12 at the second fluid inlet 22B at the first inlet temperature. In this dehumidification mode, an appropriate valve prevents circulation of the heat transfer fluid through the pipe 26, not shown here, which connects the first fluid outlet 24A of the second heat exchanger 14 to the first fluid inlet 22B of the first heat exchanger 12. In other words, the heat transfer fluid circuit 20 comprises two independent portions, with a first portion dedicated solely to the second heat exchanger 14 and a second portion dedicated solely to the first heat exchanger 12.In the first portion of the heat transfer fluid circuit 20, the heat transfer fluid is at a temperature allowing the cooling of the air flow 2 in the second heat exchanger 14, and in the second portion it is at a temperature allowing the heating of said air flow 2 in the first heat exchanger 12.

[0075] Once the dehumidification mode has been implemented within the heat treatment system 1, moisture may remain within the first heat exchanger 12 which was used in its cooling mode so as to condense the water present in the air flow 2. In order to prevent any risk of damage to the first heat exchanger 12, it is necessary to ensure, before it is used again in its heating mode, that no water remains within it. For this purpose, the heat treatment system 1 is provided with a control system, not shown in the figures, which makes it possible to ensure the absence of water within the first heat exchanger 12. The control system thus comprises a humidity or temperature sensor arranged within the heat treatment system 1, which is configured to detect a humidity level or a temperature within the first heat exchanger 12.Such a humidity or temperature sensor incorporates, for example, a PTC effect resistor. In certain embodiments, the humidity or temperature sensor is configured to detect a humidity level or a temperature within the second heat exchanger 14. The humidity or temperature sensor is, for example, used to measure, within the second heat exchanger 14, the temperature of the water or the air flow 2 during use of the dehumidification mode.

[0076] The control system is more generally configured to control the mode used by the first exchanger 12. Following the use of the dehumidification mode, the control system intervenes to prevent the use of the heating mode of the first heat exchanger 12 for a predetermined duration. During this predetermined duration, which corresponds to a time necessary for to ensure the absence of humidity, the use of the heating mode of the first heat exchanger 12 is prevented as long as the humidity or temperature sensor detects a humidity or a temperature greater than a predetermined threshold value. During this predetermined duration, the first heat exchanger 12 is in its inactive state, that is to say it is not traversed by the heat transfer fluid, and the risks of damage are therefore limited.

[0077] The present invention thus proposes a heat treatment system with two heat exchangers of substantially identical sizes and both necessarily crossed by a flow of air intended to be heated and / or cooled, the presence of these two heat exchangers making it possible to diversify the operating modes of the heat treatment system while limiting costs and space requirements.

[0078] The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and configuration as well as to any technically effective combination of such means.

Claims

Claims

1. A heat treatment system (1) for a vehicle comprising a housing (4) of a thermal installation intended to be traversed by an air flow (2) intended to be heated and / or cooled, comprising at least one circulation duct (6) for the air flow (2), the heat treatment system (1) further comprising a heat transfer fluid circuit (20), the heat treatment system (1) being characterized in that it comprises a first heat exchanger (12) and a second heat exchanger (14) arranged successively in the circulation duct (6), the first heat exchanger (12) being closer to an inlet of the air flow (2) in the circulation duct (6) than the second heat exchanger (14), the heat exchangers (12, 14) each being connected to the heat transfer fluid circuit (20) by a fluid inlet (22, 22A, 22B) and a fluid outlet (24, 24A, 24B), at least one of the two heat exchangers (12,14) being configured to alternately present at least one cooling mode and one heating mode, this heat exchanger (12, 14) being configured to be crossed by the heat transfer fluid at a first inlet temperature in its cooling mode and by the heat transfer fluid at a second inlet temperature in its heating mode.,

2. Heat treatment system (1) according to the preceding claim, wherein the first inlet temperature and the second inlet temperature have a difference of between 20 and 40°C.

3. A heat treatment system (1) according to any preceding claim, wherein the first heat exchanger (12) and the second heat exchanger (14) extend over the entire passage section of the circulation duct (6).

4. A heat treatment system (1) according to any preceding claim, wherein both the first heat exchanger (12) and the second heat exchanger (14) are configured to have at least the cooling mode and the heating mode.

5. A heat treatment system (1) according to any preceding claim, wherein the first heat exchanger (12) and / or the second heat exchanger (14) are configured to have an inactive state.

6. Heat treatment system (1) according to the preceding claim, wherein one of the heat exchangers (12, 14) is in its cooling mode or in its heating mode when the other is in its inactive mode.

7. A heat treatment system (1) according to claim 4, wherein the first heat exchanger (12) and the second heat exchanger (14) are both in the cooling mode or both in the heating mode.

8. A heat treatment system (1) according to claim 4, wherein the first heat exchanger (12) is in its cooling mode when the second heat exchanger (14) is in its heating mode.

9. A heat treatment system (1) according to any preceding claim, wherein the fluid inlet (22, 22A, 22B) and the fluid outlet (24, 24A, 24B) are arranged on the same side of their respective heat exchangers (12, 14).

10. A heat treatment system (1) according to any preceding claim, wherein the fluid outlet (24, 24A) of the second heat exchanger (14) is fluidically connected to the fluid inlet (22, 22B) of the first heat exchanger (12).

11. Heat treatment system (1) according to the preceding claim, being configured so that the first heat exchanger (12) is crossed by the air flow (2) before the second heat exchanger (14), and the second heat exchanger (14) is crossed by the heat transfer fluid before the first heat exchanger (12).

12. Heat treatment system (1) according to any one of the preceding claims, comprising a system for controlling the mode used by at least the first heat exchanger (12).

13. Heat treatment system (1) according to the preceding claim, wherein the control system comprises a humidity or temperature sensor.

14. Method of using a heat treatment system (1) according to any one of the preceding claims, during which the heat transfer fluid is circulated in one and / or the other of the heat exchangers (12, 14) at a given temperature.

15. Method of using a heat treatment system (1) according to the preceding claim, during which the heat transfer fluid is circulated successively in the second heat exchanger (14) then in the first heat exchanger (12).

16. A method of using a heat treatment system (1) according to any one of claims 14 and 15 in combination with claim 4, comprising a dehumidification step during which the first heat exchanger (12) is simultaneously operated in cooling mode and the second heat exchanger (14) in heating mode.

17. A method of using a heat treatment system (1) according to the preceding claim in combination with claim 12, wherein following the dehumidification step the control system prevents the use of the heating mode of the first heat exchanger (12) for a predetermined duration.

18. A method of using a heat treatment system (1) according to the preceding claim in combination with claim 13, wherein the use of the heating mode of the first heat exchanger (12) is prevented as long as the humidity or temperature sensor detects a humidity or temperature greater than a predetermined threshold value in the vicinity of the first heat exchanger (12).

19. A method of using a heat treatment system (1) according to any one of claims 17 and 18 in combination with claim 5, wherein the first heat exchanger (12) is in its inactive state for the predetermined time.

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