Thermoregulation device and method, particularly for motor vehicles

Abstract

A thermoregulation device comprising a refrigerant circuit (1) configured to perform a thermodynamic cycle, said circuit (1) comprising a first branch (36) and a second branch (38), extending from the same first point of divergence (40) of said circuit, said first branch (36) comprising a first heat exchanger (12), intended for heat exchange with a first heat transfer fluid, said second branch (38) comprising a second heat exchanger (14), intended for heat exchange with a second heat transfer fluid, said circuit being configured to supply said first and second heat exchangers in parallel with high-pressure refrigerant from said first point of divergence (40) in at least one heat pump mode for heating said first and / or second heat transfer fluids. Figure for the abbreviation: Figure 4

Description

Title of the invention: Thermoregulation device and method, particularly for motor vehicles

[0001] The invention relates to a thermoregulation device and method, in particular for motor vehicles.

[0002] In this field, it has long been known to use a refrigerant circuit for air conditioning in a vehicle passenger compartment. More recently, with the development of hybrid or electric powertrains, it has also been proposed to extend the use of such circuits to the temperature control of electrical energy storage devices such as batteries powering the motors used to propel the vehicle.

[0003] These circuits must be able to operate in different modes, such as cooling modes for air conditioning the passenger compartment and / or cooling the batteries, and heat pump modes for heating them. Currently known circuits exhibit a certain complexity, particularly when operating in heat pump modes. Some of them include electric heaters. Others incorporate heat exchangers through which the refrigerant must pass for the temperature regulation of other components before passing through the heat exchanger for heating the battery, which can impair the circuit's efficiency.

[0004] The invention aims to overcome at least in part the previous drawbacks and proposes to this end a thermoregulation device comprising a refrigerant circuit configured to perform a thermodynamic cycle, said circuit comprising a first branch and a second branch, extending from the same first point of divergence of said circuit, said first branch comprising a first heat exchanger, intended for heat exchange with a first heat transfer fluid, said second branch comprising a second heat exchanger, intended for heat exchange with a second heat transfer fluid, said circuit being configured to supply said first and second exchangers in parallel with high-pressure refrigerant from said first point of divergence in at least one heat pump mode enabling the heating of said first and / or second heat transfer fluids.

[0005] By "in parallel", it is meant that the portion of fluid passing through one of the exchangers does not pass through the other, during the same cycle.

[0006] Thanks to such a configuration in two distinct parallel branches, namely the said first and second branches, the circuit makes it possible to pool the calories of the refrigerant fluid in the high-pressure part of the circuit, supplying each of the first and second exchangers without having to go through the other.

[0007] Preferably, said circuit includes a control element for the circulation of a portion of the refrigerant supplying said first exchanger so as to have a different pressure level between the refrigerant entering the first exchanger and the refrigerant entering the second exchanger in at least some of said heat pump mode(s).

[0008] In this way, thanks to said control element, the fluid flow rate in each branch and therefore the pressure at the inlet of each exchanger can be adapted according to heating requirements.

[0009] According to various additional features of the invention, which may be taken together or separately and which constitute so many embodiments of the invention: - said device includes a thermoregulation circuit, intended for the circulation of said first fluid to be thermoregulated, - said thermoregulation circuit includes said first heat exchanger, - said thermoregulation circuit further includes an electrical energy storage system intended to exchange heat with the first fluid to be thermoregulated, - said second heat transfer fluid is an airflow, - said control element is a valve, - said control element is located on said first branch so as to find between said point of divergence and said first exchanger according to the direction of refrigerant flow in said first branch in said heat pump mode(s), - said device is configured for circulation of the refrigerant in said first exchanger in a first direction in said heat pump mode(s) and in a reverse direction, in at least one cooling mode enabling the cooling of said first heat transfer fluid, - said first branch includes a first expansion element for said refrigerant, said first expansion element being located on said first branch so as to be upstream of said first exchanger according to the direction of circulation of the refrigerant in said first branch in said cooling mode(s), - said refrigerant circuit includes a third heat exchanger, intended to exchange heat with another heat transfer fluid, said device being configured so that the high-pressure refrigerant circulates alternately, on the one hand, in the first and / or second heat exchangers in the said heat pump mode(s) or, on the other hand, in the third exchanger in the said cooling mode(s), - said first branch and said second branch include a point of convergence, - said circuit includes a fourth heat exchanger comprising a high-pressure pass and a low-pressure pass for said refrigerant, said fourth heat exchanger being configured for heat exchange between said refrigerant passes, - said convergence point is located in said circuit so as to be upstream of said high pressure pass, according to the direction of circulation of the refrigerant in said heat pump mode(s).

[0010] The invention also relates to a thermoregulation method, said method implementing a refrigerant circuit, to perform a thermodynamic cycle, said circuit comprising a first branch and a second branch, extending from the same first point of divergence of said circuit, said first branch comprising a first heat exchanger, intended for heat exchange with a first heat transfer fluid, said second branch comprising a second heat exchanger, intended for heat exchange with a second heat transfer fluid, said method comprising a step of supplying said first and second exchangers in parallel with high-pressure refrigerant from said first point of divergence in at least one heat pump mode allowing heating of said first and / or second heat transfer fluids.

[0011] Preferably, said method further includes a step of controlling the circulation of a portion of the refrigerant supplying said first exchanger so as to have a different pressure level between the refrigerant entering the first exchanger and the refrigerant entering the second exchanger in said heat pump mode(s).

[0012] According to various additional features of the invention, which may be taken together or separately and which constitute so many embodiments of the invention: - a circulation of the refrigerant in said first exchanger takes place in a first direction in said heat pump mode(s) and in a reverse direction, in at least one cooling mode allowing said first heat transfer fluid to be cooled, - said refrigerant circuit comprising a third heat exchanger, intended to exchange heat with another heat transfer fluid, the high-pressure refrigerant circulates alternately, on the one hand, in the first and / or second heat exchangers in the said pump mode(s) heat or, on the other hand, in the third exchanger in the said cooling mode(s).

[0013] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent in the course of the detailed explanatory description that follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the accompanying schematic drawings, among which:

[0014] [Fig. 1] schematically illustrates a first embodiment of the device according to the invention;

[0015] [Fig.2] schematically illustrates a second embodiment of the device in accordance with the invention;

[0016] [Fig.3] schematically illustrates the device of [Fig.1] according to a first mode implementation of the process according to the invention;

[0017] [Fig.4] schematically illustrates the device of [Fig.1] according to a second method of implementing the process according to the invention;

[0018] [Fig.5] schematically illustrates the device of [Fig.1] according to a third method of implementing the process according to the invention;

[0019] [Fig.6] schematically illustrates the device of [Fig.1] according to a fourth method of implementing the process according to the invention;

[0020] [Fig.7] schematically illustrates the device of [Fig.1] according to a fifth method of implementing the process according to the invention;

[0021] [Fig.8] schematically illustrates the device of [Fig.1] according to a sixth mode implementation of the process according to the invention.

[0022] It should first be noted that the terms upstream and downstream used in the following description refer to the direction of flow of the fluid in question. Furthermore, the terms "first", "second", "third", ... are used solely to distinguish the components concerned from one another and do not imply any order or potential importance of said components.

[0023] In Figures 3 and following, the dashed lines [yellow in the preliminary drawings] correspond to portions of the refrigerant circuit shown without refrigerant circulation. The thicker solid lines [red in the preliminary drawings] correspond to portions of the refrigerant circuit in which the refrigerant circulates at high pressure. The intermediate-thickness solid lines [green in the preliminary drawings] correspond to portions of the refrigerant circuit in which the refrigerant circulates at intermediate pressure. The thinner solid lines [blue in the preliminary drawings] correspond to portions of the refrigerant circuit in which the refrigerant circulates at low pressure.

[0024] As illustrated in [Fig. 1], the invention relates to a temperature control device comprising a refrigerant circuit 1. The refrigerant is, for example, a subcritical fluid, such as those known as R134a or R1234yf. Alternatively, it is a supercritical fluid such as CO2 or R744. The temperature control device is intended, in particular, for use in motor vehicles.

[0025] Said circuit is configured to perform a thermodynamic cycle, in particular with a compression phase, a first heat exchange phase, an expansion phase and / or a second heat exchange phase, this by circulating in different branches.

[0026] For this purpose, said circuit preferably includes a compressor 2, at least one expansion member, here at least five expansion members 4-9, at least two heat exchangers, here five heat exchangers, 12, 14, 16, 18, 20 and an accumulator 24. It also includes one or more non-return members 25, 26 and / or circulation valves 30-32.

[0027] Said refrigerant circuit 1 is configured to allow alternative circulation of the fluid in its different branches, in particular by means of said expansion devices 4-9, provided to be controllable, of the non-return devices 25, 26 and / or of said circulation valves 30-32. It can thus be used in one or more heat pump modes, allowing the heating of first and second heat transfer fluids, and in various other operating modes, detailed later.

[0028] The first 12 of the heat exchangers is intended to exchange heat with the first heat transfer fluid. Said first exchanger 12 is formed, in particular, of a cooler.

[0029] Although not shown, said device advantageously comprises a first thermoregulation circuit, intended for the circulation of said first heat transfer fluid. Said first thermoregulation circuit comprises said first heat exchanger 12.

[0030] Said first thermoregulation circuit further comprises an electrical energy storage system, in particular one or more batteries, intended to exchange heat with the first heat transfer fluid. In other words, if the batteries need to be cooled, particularly during charging, and even more particularly during rapid charging, the heat released is dissipated into said first heat transfer fluid circulating in the first thermoregulation circuit, and said first heat transfer fluid is cooled in said first heat exchanger 12 by means of the refrigerant from the refrigerant circuit 1. If the batteries need to be heated, heat supplied by the refrigerant to the first heat transfer fluid via said first heat exchanger 12 is transported into said first circuit thermoregulation by said first heat transfer fluid up to the electrical energy storage system.

[0031] Said device advantageously includes means for regulating the flow rate of the first heat transfer fluid in said first thermoregulation circuit. This includes, for example, a pump for regulating the flow rate of the heat transfer fluid. It is thus possible to have heat exchange at said first heat exchanger 12 when said first heat transfer fluid circulates in said first heat exchanger 12 or, alternatively, to neutralize it when the first heat transfer fluid does not circulate in said heat exchanger 12, the pump being stopped.

[0032] The second heat exchanger 14 is intended to exchange heat with the second heat transfer fluid. In a first embodiment, this is, for example, a first airflow, represented by the arrow 34, intended to supply a passenger compartment of the vehicle. In this embodiment, said second heat exchanger 14 is intended to be located, in particular, at the level of a heating, ventilation and / or air conditioning unit, located under a dashboard of the vehicle. Alternatively or cumulatively, it exchanges heat with a second heat transfer fluid other than the first airflow 34, possibly by being integrated into a second thermoregulation circuit, not shown, said second thermoregulation circuit comprising a heater core intended to heat said first airflow 34 with the help of said second heat transfer fluid.The said second exchanger 14 is formed, for example, of a gas cooler, called internal, in particular when said refrigerant is CO2.

[0033] The third heat exchanger 16 is intended to exchange heat with another heat transfer fluid, for example, a second, external, airflow, illustrated by the arrow 35. This third heat exchanger 16 is intended to be located, in particular, at the front of the vehicle so that it is traversed by this second airflow 35, said second airflow 35 having previously passed through a grille of the vehicle. This third heat exchanger 16 is formed, for example, by a gas cooler, referred to as an external one, particularly when said refrigerant is CO2.

[0034] Said device is preferably configured so that the high-pressure refrigerant circulates alternately, on the one hand, in the first and / or second exchangers 12, 14 in the said heat pump mode(s) or, on the other hand, in the third exchanger 16 in one or more cooling modes, allowing to cool, in particular, the first heat transfer fluid and / or the second heat transfer fluid.

[0035] Said fourth heat exchanger 20 comprises a high-pressure pass 22a and a low-pressure pass 22b for said refrigerant, said fourth heat exchanger The heat exchanger 20 is configured for heat exchange between the refrigerant passes 22a and 22b. This fourth heat exchanger 20 thus allows heat exchange of the refrigerant with itself. This fourth heat exchanger 20 is formed, for example, by an internal heat exchanger.

[0036] The fifth exchanger 18 is intended to exchange heat with, for example, the first airflow 34. Said fifth exchanger 18 is intended to be located, in particular, at the level of the heating, ventilation and / or air conditioning unit, upstream of the second exchanger 14 according to the direction of circulation of said first airflow 34. Said fifth exchanger 18 is formed, for example, of an evaporator.

[0037] The accumulator 24 is configured for phase separation of said refrigerant, for example by allowing the accumulation of said refrigerant in liquid phase in a lower part and in gaseous phase in an upper part. It comprises an inlet 24a of said refrigerant, particularly in a two-phase liquid-vapor state, and an outlet 24b of said refrigerant, capable of delivering said refrigerant in gaseous phase.

[0038] According to the invention, said circuit comprises a first branch 36 and a second branch 38, extending from the same first divergence point 40 of said circuit. Said first branch 36 comprises the first heat exchanger 12. Said second branch comprises the second heat exchanger 14. Said circuit is further configured to supply said first and / or second heat exchangers 12, 14 in parallel with high-pressure refrigerant from said first divergence point 40 in one or at least one of the heat pump modes. By "in parallel," it is understood that, during the same thermodynamic cycle in said circuit 1, a portion of fluid passing through one of the first or second heat exchangers 12, 14 does not pass through the other.

[0039] In this way, the calories that can be supplied by the refrigerant in a high-pressure part of the circuit are pooled by supplying, in at least one or some of said heat pump modes, each of the first and second exchangers 12, 14 to simultaneously heat the first and second heat transfer fluids.

[0040] Said first branch and said second branch here include a convergence point 44. Said convergence point 44 is located in said circuit so as to be upstream of said high-pressure pass 22a, according to the direction of circulation of the refrigerant in said heat pump mode(s).

[0041] Preferably, said circuit includes a control element for the circulation of a portion of the refrigerant supplying said first heat exchanger 12 so as to have a different pressure level between the refrigerant entering the first heat exchanger 12 and the refrigerant entering the second heat exchanger 14 in the aforementioned heat pump mode(s). It is thus possible to adjust the fluid flow rate in each of the first and second branches 36, 38, and therefore the inlet pressure of each of the first and second heat exchangers 12, 14, according to heating requirements. Furthermore, it is possible to have the refrigerant flow in only one of the aforementioned first and second branches 36, 38.

[0042] Said control element is here a first 30 of the circulation valves. Said control element, in particular said first circulation valve 30, is advantageously located on said first branch 36 so as to be between said divergence point 40 and said first exchanger 12 according to the direction of fluid circulation in said first branch 36 in said heat pump mode(s).

[0043] Preferably, said device is configured for refrigerant circulation in said first heat exchanger 12 in a first direction in said heat pump mode(s) and in the opposite direction in said cooling mode(s). This allows the same heat exchanger, namely the first heat exchanger 12, to be used for both cooling and heating the batteries. For this purpose, said first branch 36 includes a first expansion element 4 for said refrigerant. Said first expansion element 4 is located on said first branch 36 so as to be upstream of said first heat exchanger 12 according to the direction of fluid circulation in said first branch 36 in said cooling mode(s).

[0044] Said refrigerant circuit 1 advantageously has a third branch 39 and a fourth branch 41 extending from a first bifurcation point 42 located at the outlet of the compressor 2. Said third branch 39 extends to the divergence point 40 where it subdivides to form said first and second branches 36, 38. Said fourth branch 41 extends to the convergence point 44. Connected in series with said third branch 39, the first and second branches 36, 38 are each parallel to said fourth branch 41, between said first bifurcation point 42 and said convergence point 44.

[0045] Between the divergence point 40 and the convergence point 44, the first branch 36 comprises successively, according to the direction of flow of the refrigerant in this branch, in the heat pump mode(s), the first circulation valve 30, the first exchanger 12 and the first expansion device 4.

[0046] Between the divergence point 40 and the convergence point 44, the second branch 38 comprises successively, depending on the direction of refrigerant flow in this branch, in the heat pump mode(s), the second heat exchanger 14 and a possible second 5 of said expansion devices. Alternatively, the second expansion device 5 is replaced by a first 25 of the non-return devices. This is illustrated in [Fig. 2] but is also applicable to the embodiment of [Fig. 1].

[0047] Between the first bifurcation point 44 and the divergence point 40, the third branch 39 includes a second 31 of said circulation valves.

[0048] Between the bifurcation point 42 and the convergence point 44, the fourth branch 41 comprises successively, according to the direction of flow of the refrigerant in this branch, in the cooling mode(s), a third 6 of said expansion members, the third exchanger 16, a fourth 7 of said expansion members and the high pressure pass 22a of said fourth exchanger 20.

[0049] Said circuit 1 further presents here a fifth branch 46, a sixth branch 48 and a seventh branch 50, configured to complete, in particular in series, the previous branch(es) 36, 38, 39, 41 or portions thereof, in order to carry out said thermodynamic cycle in the corresponding mode(s) of operation.

[0050] Said fifth branch 46 extends between a second bifurcation point 52 and an inlet of the compressor 2. Said second bifurcation point 52 is located on the fourth branch 41 between the third expansion member 6 and the third heat exchanger 16. Said fifth branch 46 comprises in series, according to the direction of flow of the refrigerant in the said heat pump mode(s), a third 32 of said circulation valves, another 26 of the non-return members, the accumulator 24 and the low-pressure pass of said fourth heat exchanger 20.

[0051] Said sixth branch 48 connects the fourth branch 41 to the fifth branch 46. It is located between the convergence point 44 and a first junction point 54. Said first junction point 64 is located on said fifth branch 46 between said third circulation valve 32 and said other non-return device 26. Said sixth branch 48 comprises successively between the convergence point 44 and the first junction point 54, according to the direction of flow of the refrigerant in the cooling mode(s), a fifth 8 of said expansion devices and said fifth heat exchanger 18.

[0052] Said seventh branch 50 connects said first branch 36 and said fifth branch 46. It extends between a third bifurcation point 56 and a second junction point 58. Said third bifurcation point 56 is located on the first branch 36 between the divergence point 40 and the first exchanger 12. Said second junction point 58 is located on the fifth branch 46 between the non-return member 54 and the accumulator 24. Said seventh branch 50 includes a sixth 9 of said expansion members.

[0053] According to the embodiment of [Fig. 2], alternatively, said convergence point 44 is located downstream of said high-pressure pass 22a, according to the direction of refrigerant flow in said heat pump mode(s). In this mode, the high-pressure pass 22a of the fourth heat exchanger 20 passes from said fourth branch 41 to said first branch 36. More precisely, it is located between said point of convergence 44 and a fourth bifurcation point 44' connecting said first branch 36 and said sixth branch 48 upstream of said first expansion valve 4 according to the direction of fluid flow in said cooling mode(s). Otherwise, the circuit is identical to that described above.

[0054] As illustrated in [Fig.3], according to a first mode of operation, said device operates as a heat pump by passing through the second branch 38 without passing through the first branch 36.

[0055] In this mode, the refrigerant flows through the third branch 39 exiting the compressor 2, with the second valve 31 open and the third expansion valve 6 closed. It then passes into the second branch 38, with the first valve 30 closed. The heat available in the refrigerant, which is now at high pressure, is transferred to the second heat transfer fluid, which is heated by means of the second heat exchanger 14. The first airflow 34 can then heat the vehicle's passenger compartment. Downstream, the refrigerant passes through the second expansion valve 5, which is open and inactive. It then continues its path through the portion of the fourth branch 41 located between the convergence point 44 and the second bifurcation point 52, with the first and fifth expansion valves 4 and 8 closed.It thus passes through the high-pressure pass 22a of the fourth exchanger 20, into the fourth expansion device 7 which is active and causes an expansion of said refrigerant which then passes to low pressure and then passes through the third exchanger 16 taking heat from the second air flow 35. Downstream of the second bifurcation point 52, the refrigerant takes the fifth branch 46 to return to the compressor 2 via the other non-return device 26, the accumulator 24 and the low-pressure pass 22b of the fourth exchanger 20.

[0056] According to this embodiment, the calories taken from the second airflow 35 are transferred to the first airflow 34 via the thermodynamic cycle described by the refrigerant.

[0057] As illustrated in [Fig.4], according to a second mode of operation, said device again operates as a heat pump, this time passing through both the first branch 36 and the second branch 38.

[0058] In this mode, the refrigerant follows the same circuit as in the first embodiment, the difference being that the fluid divides into a first portion and a second portion at the divergence point 40. Only the second portion passes into the second branch 38 while the first portion passes into the first branch 36, said first circulation valve 30 being open and the sixth expansion member 9 being closed.

[0059] In the first branch 36, the calories available in the first portion of refrigerant, which is then at high pressure, are transferred to the first The heat transfer fluid is heated via the first heat exchanger 12. This allows the batteries to be heated. Downstream, the refrigerant passes through the first expansion valve 4, which is open and inactive. It then joins the second portion of refrigerant, which has passed through the second branch 38, at the convergence point 44.

[0060] In the second branch 38, the heat available in the second portion of refrigerant, which is then at high pressure, is transferred to the second heat transfer fluid, which is heated by means of the second heat exchanger 14. If the second heat transfer fluid is the first airflow 34, it can then heat the vehicle's passenger compartment. Downstream, the refrigerant passes through the first expansion valve 4, which is open and inactive. It then rejoins the first portion of refrigerant that passed through the first branch 36, at the point of convergence 44.

[0061] Downstream, the refrigerant follows the same path as in the first embodiment, taking calories from the second airflow 35.

[0062] According to this embodiment, the calories taken from the second airflow 35 are transmitted to both the batteries and the first airflow 34 via the thermodynamic cycle described by the refrigerant, this by passing through each of the first and second branches 36, 38.

[0063] As already mentioned above, this heat transfer sharing is advantageously controlled, here by means of the first circulation valve 30 which, depending on a degree of opening, makes it possible to determine the quantity of refrigerant sent to each of the first and second branches 36, 38. It should be noted that the location of said first valve 30 upstream of said first heat exchanger 12 and / or said second heat exchanger 14 allows for more deterministic control than with a control device located downstream, such as the first expansion device 4 and / or the second expansion device 5. Alternatively, said expansion devices 4, 5 are used for such control, either alternatively or in combination with the first circulation valve 30.

[0064] In the operating mode of [Fig.4], the degree of opening of the first valve 30 is configured so that the pressure of the first portion and the second portion of refrigerant fluid is substantially the same.

[0065] In the operating mode of [Fig. 5], the circulation of the refrigerant is the same as in [Fig. 4]. The difference lies in the degree of opening of the first valve 30, which is configured so that the pressure of the first portion of refrigerant is higher than the pressure of the second portion of refrigerant. While thus heating both the first and second heat transfer fluids, it is possible to favor the heating of the first heat transfer fluid. The batteries can thus be heated strongly while continuing to heat the passenger compartment, even if the passenger compartment heating is carried out with less power than in the operating mode of [Fig.4].

[0066] As illustrated in [Fig. 6], according to another operating mode, the device functions in cooling mode for the first heat transfer fluid. As mentioned above, it passes through the first heat exchanger 12 in the opposite direction to that used in the heat pump mode. In the illustrated embodiment, the device also provides cooling for the first airflow 34 at the fifth heat exchanger 18.

[0067] More specifically, the refrigerant flows through the fourth branch 41 at the outlet of the compressor 2, with the second valve 31 closed and the third expansion valve 6 open but inactive. It then passes through the third heat exchanger 16, with the third valve 32 closed. At this point, it is at high pressure, and its heat is dissipated in the second airflow 35. Downstream, the refrigerant passes through the fourth expansion valve 7, which is open but inactive. It then continues its path through the high-pressure passage 22a of the fourth heat exchanger 20 and simultaneously flows through the first branch 36 and the sixth branch 48, between the convergence point 44 and the second junction point 58. In other words, at the convergence point 44, the refrigerant splits into two portions: a first portion passing through the first branch 36 and a second portion passing through the sixth branch 48.

[0068] In the first branch 36, the first portion circulates, as already stated, in the opposite direction to that of the heat pump modes. More precisely, it passes through the first expansion valve 4, which is active and causes an expansion of said first portion of the refrigerant. It then passes into the first heat exchanger 12, where it extracts heat from the first heat transfer fluid, which is thus cooled. This cooled heat transfer fluid can then, in turn, cool the coils. At the third branch 56, said first portion leaves the first branch 36 to pass into said seventh branch 50, said first circulation valve 30 being closed. It then passes into said sixth expansion valve 9, which is open and inactive, to reach the second junction point 58.

[0069] In the sixth branch 48, the second portion passes through the fifth expansion valve 8, which is active and causes an expansion of said second portion of the refrigerant. It then passes into the fifth heat exchanger 18, where it extracts heat from the first airflow 34, which is thus cooled. Said first airflow 34 can then cool the vehicle's passenger compartment. Downstream, said second portion joins the fourth branch 46 at the first junction point 54 and then the second point junction 58 passing through the said other non-return device 26, the third valve 32, as a reminder, being closed.

[0070] At said second junction point 58, the first and second portions of refrigerant join together and the refrigerant continues its path along the remaining portion of said fourth branch 46 to return to the compressor 2 via the accumulator 24 and the low pressure pass 22b of the fourth exchanger 20.

[0071] According to this embodiment, the calories taken from the first refrigerant and the first airflow 34 are transferred to the first airflow 35 via the thermodynamic cycle described by the refrigerant.

[0072] According to additional operating modes, not illustrated, said device operates in cooling mode of the first heat transfer fluid or the first air stream 34 by passing through the first branch 36, as described above, but without passing through the sixth branch 48, or by passing through the sixth branch 48, as described above, but without passing through the first branch 36. In these operating modes, the entire refrigerant and not just a portion passes respectively through the first branch 36 or through the sixth branch 48.

[0073] As mentioned above, it is understood that the high-pressure refrigerant circulates alternately, on the one hand, in the first and / or second heat exchangers 12, 14 in the heat pump mode(s), as in Figures 3 to 5, or, on the other hand, in the third heat exchanger 16, in the cooling mode(s), as in [Fig. 6]. For this purpose, it uses either the third branch 39 or the fourth branch 41 at the outlet of the compressor 2.

[0074] As illustrated in [Fig. 7], according to another operating mode, said device operates in a hybrid manner with cooling of the first heat transfer fluid via the first heat exchanger 12 and heating of the second heat transfer fluid via the second heat exchanger 14. Such an operating mode can be viewed as a heat pump mode allowing the recovery of heat from the second air stream 35 and the first heat transfer fluid to be transferred to the second heat transfer fluid, in particular said first air stream 34. It is thus possible to recover not only the heat available in the second air stream 35 but also, via the first heat transfer fluid, that from the heat released by the batteries.

[0075] In this mode, the refrigerant follows the same circuit as in the first operating mode, illustrated [Fig. 3], up to the convergence point 44. It then divides into a first portion and a second portion. From said convergence point 44, the first portion passes into the first branch 36 according to the same circuit as the corresponding portion according to the operating mode of [Fig. 6] and the the second portion follows the same circuit as the refrigerant in the first operating mode.

[0076] The first and second portions meet at the level of said second junction point 58 and the low-pressure refrigerant returns to the compressor as in each of these operating modes already mentioned.

[0077] As illustrated in [Fig.8], according to a complementary operating mode, the refrigerant allows cooling of the first airflow 34 by means of said fifth exchanger 18 and heating of said first airflow 34 by means of the second exchanger 14, in particular for demisting the passenger compartment, as well as dissipating heat in the second airflow 35 at the level of said third exchanger 16, in particular for defrosting it, if necessary.

[0078] In this embodiment, the refrigerant is divided into a first portion and a second portion at the outlet of the compressor 2, said first and second portions circulating in parallel up to the point of convergence 44.

[0079] The first portion follows the third branch 39 and then the second branch 38, as in the first mode of operation of the [Fig.3].

[0080] The second portion follows the fourth branch 41, passing through the third expansion valve 6, which is open and active. This second portion undergoes slight expansion at the third expansion valve and thus reaches an intermediate pressure before passing through the third heat exchanger 16, with the third valve 32 closed. The second portion continues downstream, passing through the fourth expansion valve 7, which is open and inactive, and then through the high-pressure 22a of the fourth heat exchanger 20 before rejoining the first portion of refrigerant at the convergence point 44.

[0081] The refrigerant continues downstream in the sixth branch 48, the first valve 30 being closed, as well as the first expansion valve 4 and / or the sixth expansion valve 9. The refrigerant thus passes through the fifth expansion valve 8, which is active and causes the refrigerant to expand. The latter is then at low pressure. It then passes through the fifth heat exchanger 18 and joins the fourth branch 46 at the first junction point 54, from which it travels the remaining portion, passing through the other non-return valve 26, the accumulator 24, and the low-pressure pass 22b of the fourth heat exchanger 20, before returning to the compressor 2.This path of the heat transfer fluid is made possible in particular because the third valve 32, as a reminder, is closed and said refrigerant cannot take the seventh branch 50 at the level of said second junction point 58, if only because of the pressure levels involved at each end of said seventh branch 50.

Claims

Demands

1. Thermoregulation method, said method employing a refrigerant circuit (1) to perform a thermodynamic cycle, said circuit (1) comprising a first branch (36) and a second branch (38), extending from the same first divergence point (40) of said circuit, said first branch (36) comprising a first heat exchanger (12), intended for heat exchange with a first heat transfer fluid, said second branch (38) comprising a second heat exchanger (14), intended for heat exchange with a second heat transfer fluid, said method comprising a step of supplying said first and second exchangers (12, 14) in parallel with high-pressure refrigerant from said first divergence point (40) in at least one heat pump mode for heating said first and second heat transfer fluids,said refrigerant circuit (1) comprising a third heat exchanger (16), intended to exchange heat with another heat transfer fluid, the high-pressure refrigerant circulates alternately, on the one hand, in the first and / or second heat exchangers (12, 14) in the said heat pump mode(s) or, on the other hand, in the third heat exchanger (16) in the said cooling mode(s).

2. Method according to claim 1 further comprising a step of controlling the circulation of a portion of the refrigerant supplying said first exchanger (12) so as to have a different pressure level between the refrigerant entering the first exchanger (12) and the refrigerant entering the second exchanger (14) in said heat pump mode(s).

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