FR3059273A1 - AIR CONDITIONING SYSTEM, IN PARTICULAR FOR A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to an air conditioning system for a compartment, particularly a vehicle cabin, said system being configured to be traversed by a refrigerant, said system comprising an ejector (10), said ejector (10) comprising: a low pressure inlet (20) connected to a low pressure inlet branch (22) of the refrigerant in the ejector (10); An outlet of the refrigerant (30), connected to an outlet branch (32) of the refrigerant from the ejector (10), said system comprising a bypass branch (70) connecting the low pressure inlet branch ( 22) to said output branch (32), said system being configured to selectively permit refrigerant flow in the low pressure input branch (22) of the ejector (10) or in the bypass branch (70). .

Description

059 273

61578 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number:

(to be used only for reproduction orders) (© National registration number

COURBEVOIE © IntCI ⁸ : B 60 H 1/00 (2017.01)

PATENT INVENTION APPLICATION

A1

©) Date of filing: 28.11.16. © Applicant (s): VALEO THERMAL SYSTEMS (© Priority: Simplified joint stock company - FR. @ Inventor (s): YAHIA MOHAMED, NICOLAS BERTRAND, HALLER REGINE, THUEZ JEAN-LUC, (43) Date of public availability of the LIU JIN-MING and CLEMARON LAETITIA. request: 01.06.18 Bulletin 18/22. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): VALEO THERMAL SYSTEMS related: Joint stock company. ©) Extension request (s): © Agent (s): VALEO THERMAL SYSTEMS.

(04) AIR CONDITIONING SYSTEM, ESPECIALLY FOR A MOTOR VEHICLE.

FR 3,059,273 - A1 (o7) The invention relates to an air conditioning system for a compartment, in particular a vehicle interior, said system being configured to be traversed by a refrigerant, said system comprising an ejector (10) , said ejector (10) comprising:

a low pressure inlet (20) connected to a low pressure inlet branch (22) of the refrigerant in the ejector (10);

an outlet for the refrigerant (30), connected to an outlet branch (32) for the refrigerant from the ejector (10), said system comprising a bypass branch (70) connecting the low pressure inlet branch (22 ) to said outlet branch (32), said system being configured to selectively allow a circulation of the refrigerant in the low pressure inlet branch (22) of the ejector (10) or in the bypass branch (70).

Air conditioning system, in particular for a motor vehicle

The invention relates to a system for conditioning an air flow entering a compartment, for example a passenger compartment of a motor vehicle, in particular a system for ventilation, heating and / or air conditioning of the compartment.

Motor vehicles are commonly equipped with a ventilation, heating and / or air conditioning system to modify the aerothermal parameters of the air contained inside the vehicle interior. Such a modification is obtained from the delivery of a pulsed air flow inside the passenger compartment. In the case of an electric or hybrid vehicle, the propulsion of which is provided at least partially by an electric motor, such a system is necessarily adapted to the permanent absence (electric vehicle) or temporary (hybrid vehicle) of hot source such as '' a heat engine on this type of vehicle.

Such a system is expected to fulfill at least the following functions: Cooling, also called air conditioning,

Heating, also called heat pump,

Dehumidification, i.e. treatment of the air blown into the passenger compartment so as to cause the condensation of part of the water vapor it contains.

Such a system comprises in known manner an air conditioning unit usually housed under a dashboard of the vehicle.

The housing has a ventilation unit, it receives an external air flow and draws it for delivery inside the passenger compartment. Inside this housing are usually housed a first heat exchanger, intended for cooling the passenger compartment, and a second heat exchanger, intended for heating the passenger compartment. These different organs are connected to each other and to another heat exchanger, called an external heat exchanger, located on the front face of the vehicle for exchanging heat with an external air flow, by a circuit of pipes in which a refrigerant circulates. This circuit further comprises a compressor, at least one pressure reducing valve capable of decompressing the fluid and means such as valves for differently orienting the fluid in the different pipes according to the operating mode sought by Γ user.

This system can be used in cooling mode or in heating mode. In cooling mode, the refrigerant is sent from the compressor to the outside heat exchanger acting as a condenser where it is cooled by the outside air flow. Then, the refrigerant circulates to a pressure reducer where it undergoes a lowering of its pressure before entering the first heat exchanger operating as an evaporator. The refrigerant passing through the evaporator is then heated by the air flow entering the ventilation installation, which correlatively results in a cooling of this air flow in order to cool the passenger compartment of the vehicle. The circuit being a closed loop, the refrigerant then returns to the compressor.

In heating mode, the refrigerant is sent from the compressor to the first and / or the second heat exchanger. The latter then behave like condensers, in which the refrigerant is cooled by the air circulating in the ventilation installation. This air therefore heats up in contact with the first and / or second exchanger and thus brings calories to the passenger compartment of the vehicle. After passing through this or these exchangers, the refrigerant is expanded by a pressure reducer before arriving in the external heat exchanger acting as an evaporator. It is then heated by the outside air. The refrigerant then returns to the compressor.

Another useful mode for the user is that which is called heat recovery, in which the cabin is heated only by means of the first and second exchangers of the housing, that is to say by putting the outdoor heat exchanger. This mode is used when the outside temperature is low and the outside heat exchanger, which in heating mode operates as an evaporator, frost or is about to frost. We then use the interior's own heat, which at this stage is normally already at a certain temperature.

Systems are also known comprising an ejector, that is to say a device comprising a high pressure inlet, a low pressure inlet and an outlet. The high pressure inlet has a nozzle, followed by a convergent-divergent which communicates with the low pressure inlet. The high pressure primary fluid is accelerated and relaxed within the convergent-divergent flow, which creates a pressure drop which has the effect of sucking in the low pressure secondary fluid. The ejector therefore makes it possible to convert the expansion work into a work of compression of the refrigerant. The interest of an ejector is then to increase the pressure of the fluid entering the compressor, and thus to decrease the work necessary for compression by the compressor, which improves the efficiency of the cycle and therefore its coefficient of performance.

However, for such systems to produce the expected effect, certain operating conditions must be fulfilled to allow priming of the ejector, that is to say, for sufficient suction to take place at the level of the low pressure inlet, under the effect of the flow coming from the high pressure inlet, this so that a relaxation and a suction of the fluid takes place effectively.

However, such operating conditions are not always present and the ejector, instead of improving the performance of the systems, degrades them.

In addition, depending on the configuration of the air conditioning system used, the ejector is not always necessary, in particular in heating mode or in heat recovery mode. As before, instead of improving the performance of the systems, the ejector then degrades them.

The invention aims to overcome all or part of the aforementioned drawbacks and proposes for this purpose an air conditioning system for a compartment, in particular a passenger compartment, said system being configured to be traversed by a refrigerant, said system comprising an ejector, said ejector comprising a low pressure inlet, connected to a low pressure inlet branch of the refrigerant in the ejector, and a refrigerant outlet, connected to an outlet branch of the refrigerant out of the ejector .

According to the invention, said system comprises a bypass branch connecting the low pressure inlet branch to said outlet branch, said system being configured to selectively allow a circulation of the refrigerant in the low pressure inlet branch of the ejector or in the bypass branch.

In this way, in the event of a failure to prime the ejector, the refrigerant can avoid passing through it, at least from its low pressure inlet, instead passing through the bypass branch. It is the same in the operating modes where the ejector is not necessary such as the operating modes in heat pump or in heat recovery.

According to other characteristics of the invention, which can be taken together or separately:

- said bypass branch comprises a pressure reducer and / or a valve, allowing selectively to open or close the circulation of the fluid in said bypass branch,

- said regulator is waterproof,

- said circuit comprises at least one internal heat exchanger to carry out a heat exchange involving the refrigerant so as to allow treatment of an air flow to be blown inside the compartment,

- said system comprises first and second internal heat exchangers, in particular positioned in series, in this order, according to the direction of circulation of the air flow to be blown inside the compartment,

- said system is configured so that the refrigerant circulates in said low pressure inlet branch downstream of said second indoor heat exchanger,

- said bypass branch opens into said outlet branch of the ejector upstream from said first indoor heat exchanger,

- said system is configured so that, in at least certain operating modes, in particular in heat pump, heat pump with dehumidification, heat recovery or air conditioning operating modes without priming the ejector, the refrigerant circulates from the second exchanger indoor heat to the first indoor heat exchanger via the bypass branch,

- said conditioning system comprises a compressor,

- said compressor is supplied by said outlet branch of the ejector,

- said first indoor heat exchanger is located on said outlet branch,

- said conditioning system comprises a third internal heat exchanger,

- in at least certain operating modes, in particular in heat pump, heat pump with dehumidification and heat recovery modes, said system is configured to supply in series in this order, the third indoor heat exchanger, the second indoor heat exchanger and the first interior exchanger, passing through the bypass branch between the second and first interior heat exchangers, this in particular from said compressor,

- said circuit comprises an external heat exchanger to carry out a heat exchange between the refrigerant and a flow of air circulating outside the compartment,

- the ejector includes a high pressure inlet for the refrigerant, connected to a high pressure inlet branch for the refrigerant in the ejector,

- said system is configured so that, in at least certain operating modes, in particular in air conditioning or air conditioning with dehumidification modes, the refrigerant supplies the second indoor heat exchanger and the high pressure inlet of the ejector, the low inlet pressure of the ejector being supplied from said second interior exchanger,

- in a heat pump mode, said system is configured to take heat from the air outside the compartment using the external heat exchanger and reject it in the air flow to be blown inside the compartment using one or at least one of the internal heat exchangers,

- Said system further comprises a so-called internal heat exchanger, said system being configured so that a heat exchange takes place between said refrigerant and itself in said internal exchanger, in cooling mode and at least in mode heat pump.

The invention also relates to an air conditioning method using the conditioning system described above, in particular in air conditioning mode without priming the ejector.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below for information only in relation to the drawings in which:

FIG. 1 is a schematic illustration of an air conditioning system according to the present invention,

- Figure 2 shows Figure 1, the conditioning system operating in air conditioning mode, without dehumidification, in a case where the ejector is primed,

FIG. 3 reproduces FIG. 1, the conditioning system operating in air conditioning mode, without dehumidification, in a case where the ejector is not primed,

- Figure 4 reproduces Figure 1, the conditioning system operating in air conditioning mode, with dehumidification, in a case where the ejector is primed,

FIG. 5 reproduces FIG. 1, the conditioning system operating in heat pump mode, without dehumidification,

FIG. 6 reproduces FIG. 1, the conditioning system operating in heat pump mode, with dehumidification,

- Figure 7 shows Figure 1, the conditioning system operating in heat recovery mode.

In these different figures, identical elements are identified by the same references.

As illustrated in the various figures, the invention relates to an air conditioning system for a compartment, in particular a passenger compartment of a motor vehicle.

Said system comprises a closed circuit inside which a refrigerant circulates. The refrigerant is for example a supercritical fluid such as carbon dioxide referenced R-744. The refrigerant is for example still a subcritical fluid such as a fluorinated refrigerant, referenced R-134a, or another, referenced 1234yf.

Said system comprises an ejector 10 provided with a low pressure inlet 20, connected to a branch 22 for low pressure inlet of the refrigerant in the ejector

10. The ejector 10 is also provided with an outlet 30 for the refrigerant, connected to a branch 32 for the outlet of the refrigerant from the ejector 10. The ejector 10 is further provided here with an inlet 40 high pressure for the refrigerant, connected to a branch 42 of high pressure inlet for refrigerant in the ejector 10.

Said ejector comprises, for example, a nozzle opening into a convergent-divergent. The high pressure inlet 40 feeds the nozzle for sucking the fluid into the low pressure branch 22. The portion of fluid entering through the high pressure inlet 40 is accelerated and expanded within the converging-diverging, which creates a pressure drop which has the effect of sucking in the converging-diverging portion of fluid entering through the low pressure inlet 20. The two portions of fluid combine in the converging-diverging and exit the ejector 10 downstream of the converging-diverging .

In the example illustrated, said system further comprises an external heat exchanger 50 for carrying out a heat exchange between the refrigerant and an air flow E circulating outside the compartment. Said external heat exchanger 50 is intended to be located, for example, on the front face of a motor vehicle. As will be detailed below, it is intended to operate in a reversible manner, either as an evaporator or as a gas condenser / cooler.

Said system also comprises at least one interior heat exchanger, preferably at least two, here three, namely a first interior heat exchanger 34, a second interior heat exchanger 24 and a third interior heat exchanger 26. Said interior heat exchangers 24, 26, 34 carry out a heat exchange involving the refrigerant. The first indoor heat exchanger 34 is configured to allow heat to be exchanged between said refrigerant and an air flow I to be blown, or pulsed, inside the passenger compartment. The second exchanger 24 is here also configured to allow heat exchange between said refrigerant and said air flow I to be blown inside the passenger compartment. As will be detailed below, said first and second indoor heat exchangers 34, 24 are intended to operate in a reversible manner, either as an evaporator or as a gas condenser / cooler, and the third indoor heat exchanger 26 is intended to operate in gas condenser / cooler.

The said interior heat exchanger (s) 24, 26, 34 are located inside a housing 1, said to be of air conditioning, for circulation of the air flow I intended to be blown into the passenger compartment. The first 34 of said interior heat exchanger is located upstream from the second 24 of said interior heat exchanger, according to the direction of circulation of said air flow I to be blown inside the passenger compartment. The third 26 of said interior heat exchangers is located downstream of said second interior heat exchanger 24, always according to the direction of circulation of said air flow I to be blown inside the passenger compartment.

Said housing 1 comprises, for example a main duct 100 through which the first and / or the second internal exchangers 34, 24 are arranged. In some cases not shown here, part of the flow of forced air in the passenger compartment will not pass through not exchangers 24 and 34.

Said casing 1 may comprise one or more secondary conduits 102 through which one or more of the interior heat exchangers are arranged, here a bypass conduit accommodating the third interior exchanger 26. Said casing 1 further comprises one or more conduits bypassing said secondary conduit (s), here a conduit 104 bypassing said third interior heat exchanger 26. According to the example illustrated, the main conduit 100 opens into the secondary and bypass conduits 102, 104. A movable flap 106 directs said flow air I intended to be blown into the passenger compartment towards said third internal heat exchanger 26 and / or said bypass duct 104.

As a variant, not shown, said third interior heat exchanger may be configured to allow heat exchange with a heat transfer fluid circulating in a circulation loop of said heat transfer fluid, said circulation loop of the heat transfer fluid comprising an additional heat exchanger allowing a heat exchange between said heat transfer fluid and said air flow I intended to be blown into the passenger compartment. Said additional heat exchanger is positioned in the air conditioning unit in place of the second interior heat exchanger which can then be outside the housing.

Said system further comprises a heat exchanger 51, said internal, and said system comprises a circulation branch 52, said high pressure, and a circulation branch 54, said low pressure, intended to pass through said internal exchanger. Said internal exchanger is configured to allow a heat exchange between said refrigerant circulating in said low pressure circulation branch 54 and the refrigerant circulating in said high pressure circulation branch 52.

The system also includes a compressor 2 for carrying the refrigerant at high pressure, an accumulator 4, making it possible to store the refrigerant, or even to operate a phase separation, as well as a first expansion member 201, associated with the second exchanger of interior heat 24, a second expansion member 202, associated with the exterior heat exchanger 50 and a third expansion member 203 to which we will return later. Inside said expansion members 201, 202, 203 the refrigerant undergoes expansion. Said first, second and / or third expansion members may be leaktight regulators and play the role of control valve making it possible to authorize or prevent the passage of the refrigerant. They may also be fully open and not operate any relaxation. As a variant, said expansion members are not leaktight and may be associated with control valves making it possible to open or close the circulation of the fluid through the corresponding expansion member.

The system has a particular architecture to offer different modes of operation, as described below. More particularly, the system comprises several circulation lines 61-67 through which the refrigerant circulates or does not circulate according to the open or closed position of the sealed expansion members 201, 202, 203 - or of control valves associated with members non-watertight expansion valves - specific control valves 301, 302, 303, 304 and / or non-return valves 401, 402, 403, 404, 405 that the circulation lines 61-67 include. These circulation lines 61-67 are connected to each other by means of junction points referenced 501-511. The specific control valves are, for example, sealed or not. They can be of the all or nothing type, that is to say, configured to occupy only a fully closed position and a fully open position. They may alternatively be with progressive opening, in particular linear, that is to say configured to occupy any intermediate position between their fully closed position and their fully open position. Non-return control valves are, for example, non-return valves.

The system comprises in particular a first circulation line 61 which successively comprises the compressor 2, a first junction point 501, a first control valve 301, a second junction point 502, the external heat exchanger 50, a third point junction 503, a first non-return valve 401 authorizing the passage of the refrigerant only from the third junction point 503 to a fourth junction point 504 of said first circulation line 61. Then, the first circulation line 61 successively comprises the branch of high pressure circulation 52 of the internal exchanger 51, a fifth junction point 505 and a sixth junction point 506 from which said first circulation line diverges.

According to a first branch of said first circulation line 61, the sixth junction point 506 is connected to the high pressure inlet branch 42 in the ejector 10. According to a second branch of said first circulation line 61, the sixth point junction 506 is connected to a second non-return valve 402 authorizing the passage of the refrigerant only from the sixth junction point 506 to a seventh junction point 507. Following said seventh junction point 507, the second branch of the first circulation line 61 successively comprises the first expansion member 201 and then the second interior heat exchanger 24.

The system also includes a second circulation line 62 which starts from the second internal heat exchanger 24 to go to an eighth junction point 508, connected to the low pressure inlet branch 22 in the ejector 10. More generally, said system is configured so that the refrigerant circulates in said low pressure inlet branch 22 downstream of said second indoor heat exchanger 24, at least in certain operating modes.

The system comprises a third circulation line 63. Said third circulation line 63 successively comprises the outlet branch 32 outside the ejector 10, a ninth junction point 509, the first interior exchanger 34, a tenth junction point 510, a second control valve 302, an eleventh junction point 511, the accumulator 4 and the low pressure branch 54 of the internal exchanger 51 to return to the compressor 2. In other words, more generally, said compressor 2 is supplied by said outlet branch 32 outside the ejector 10 and said first internal heat exchanger 34 is located on said outlet branch 32, here beyond the ninth junction point 509.

The system also includes a fourth refrigerant circulation line 64 which extends between the first junction point 501 and the seventh junction point 507. The fourth circulation line 64 successively comprises, from the first junction point 501 towards the seventh junction point 507, a third control valve 303 and the third internal heat exchanger 26, or even a third non-return valve 403, passing from the first junction 501 to the seventh junction point 507. The order of the third control valve 303 and the third indoor heat exchanger 26 can be reversed.

The system also comprises a fifth circulation line 65 of refrigerant which extends between the second junction point 502 and the eleventh junction point 511 and which comprises a fourth control valve 304, or even a fourth non-return valve 404, passing from the second junction point 502 to the eleventh junction point 511.

The system also includes a sixth circulation line 66 which extends between the tenth junction point 510 and the fifth junction point 505 and which includes a fifth non-return valve 405 allowing the passage of the refrigerant only from the tenth junction point 510 to the fifth junction point 505.

The system also includes a seventh circulation line 67 which extends between the third junction point 503 and the fourth junction point 504 and which comprises the second expansion member 202.

According to the invention, the system comprises a bypass branch 70 connecting the low pressure inlet branch 22 to said outlet branch 32 of the ejector 10. In other words, the bypass branch connects the second and the third circulation line 62, 63 by short-circuiting the low pressure input 20 and the output 30 of the ejector 10.

In addition, said system is configured to selectively allow a circulation of the refrigerant in the low pressure branch 22 of the ejector 10 or in the bypass branch 70. For this, said bypass branch 70 here comprises the third regulator 203, provided waterproof or associated with a control valve. As a variant, the bypass branch only comprises a control valve, without an expansion valve.

Thanks to said bypass branch 70, it is understood that the system allows the refrigerant to circulate without necessarily having to pass through the ejector 10, in particular through the low pressure inlet 20 of the ejector 10. In fact, when the third regulator 203 is closed, the portion of the refrigerant coming from the second interior exchanger 24 passes through said low pressure inlet 20 of the ejector 10 while, when said third regulator 303 is open, the same portion of the refrigerant borrows the branch of bypass 70 to go to the compressor 2 without passing through the ejector 10. In this way unnecessary pressure drops are avoided. Examples of operating modes of the system where such circulation finds its interest will be detailed below.

Advantageously, said bypass branch 70 opens into said outlet branch of the ejector 10 upstream from said first internal heat exchanger 24. More specifically, the bypass branch 70 here connects the eighth and ninth junction points 508, 509. The third pressure reducer 203 then finds its utility by enabling expansion of the refrigerant before it enters the first internal heat exchanger 34.

As mentioned above, the system is capable of operating in various variants. More particularly, the refrigerant circuit 19 is able to operate at least:

- In a first operating variant, called cooling or air conditioning, in which the air flow I is cooled prior to delivery of the latter inside the passenger compartment of the motor vehicle, in other words, an operating variant in which the system takes heat from the air flow to be blown inside the compartment using the first and / or second internal heat exchanger 34, 24 and rejects it in the air flow circulating outside the compartment using at least said external heat exchanger 50,

- In a second operating variant, called a heat pump or heating, in which the air flow I is heated prior to its delivery inside the passenger compartment of the motor vehicle, in other words, an operating variant in which the system draws heat from the air outside the compartment using the external heat exchanger 50 and rejects it in a flow of air to be blown inside the compartment using or at least one of the internal heat exchangers 24, 26, 34,

- In a third operating variant, called heat recovery, in which it takes heat from the air flow intended to be blown inside the compartment using at least one of the heat exchangers internal heat 24, 26, 34 and rejects it into the same air flow using the other internal heat exchanger (s) 24, 26, 34.

As will be developed below, these operating variants are available in different modes, whether or not incorporating a dehumidification function.

By convention in FIGS. 2 to 7, the circulation lines 61-67 or parts of circulation lines 61-67 through which no fluid circulates are shown in dotted lines, while the circulation lines 61-67 or parts of circulation lines 61-67 through which the refrigerant circulates are shown in solid lines. The same is true for the bypass branch 70.

In FIG. 2, the system is used in air conditioning mode to cool the internal air flow I prior to its delivery inside the passenger compartment, without dehumidification, the ejector 10 being primed. In this configuration, the third control valve 303 and the fourth control valve 304 are closed as well as the second and third sealed expansion members 202, 203.

Thus, downstream of the compressor 2, the refrigerant borrows the first circulation line 61 without circulating in the fourth circulation line 64. In other words, the refrigerant is compressed inside the compressor 2 to be brought to a high pressure HP, then flows to the first junction point 501, then passes through the first control valve 301 (open position), then flows to the second junction point 502, then flows inside the outdoor heat exchanger 50, operating as a gas condenser / cooler, inside which the refrigerant transfers calories to the external air flow E. Then, the refrigerant circulates to the third junction point 503, then borrows the first check valve -return 401, bypassing the second expansion member 202, then circulates to the fourth junction point 504, then borrows the high pressure branch 52 inside which the refrigerant transfers calories to the fluid e refrigerant present in the low pressure branch 54. Then, the refrigerant circulates to the fifth and sixth junction points 505, 506.

At this level, it is divided into two portions. The first portion circulates to the high pressure inlet 40 via the high pressure inlet branch 42 in the ejector

10. The second portion circulates through the second non-return valve 402 to the seventh junction point 507 then the first expansion member 201, in which the refrigerant is expanded, before entering the second interior exchanger 24, operating in evaporator, to cool the air flow I intended to be blown inside the passenger compartment.

Downstream of the second interior heat exchanger 24, the second portion of the refrigerant borrows the second circulation line 62. In other words, it passes through the eighth junction point 508 to enter the ejector 10 via its low pressure inlet 20 at borrowing the low pressure inlet branch 22 into the ejector 10, this because the bypass branch 70 is closed.

As explained above, the two portions of refrigerant combine in the ejector 10, with the suction effect expected from the portion entering the ejector 10 through its low pressure inlet 20. The fluid then leaves the ejector 10 through its outlet 30 to take the third circulation line 63 through the outlet branch 32 out of the ejector 10.

Downstream, the refrigerant circulates through the ninth junction point 509 then, in the example illustrated, the first indoor heat exchanger 34, operating as an evaporator, to cool the air flow I intended to be blown to the interior of the passenger compartment. It can thus be seen that, according to such an embodiment, the interior air flow I is cooled twice in series, a first time by the first indoor heat exchanger 34 and a second time by the second indoor heat exchanger 24. Configurations with only the second indoor heat exchanger are also possible.

The refrigerant then circulates to the tenth junction point 510, then passes through the second control valve 302 (open position), then circulates to the eleventh junction point 511, then passes through the accumulator 4 inside which a any remaining liquid refrigerant is retained, then circulates inside the low pressure branch 54 of the internal heat exchanger 51 to return to the compressor 2.

These arrangements are such that the refrigerant is at high pressure downstream of the compressor 2 to the high pressure inlet 40 of the ejector 10, on the one hand, and to the first expansion member 201, on the other hand, then at low pressure downstream of said first expansion member 201 to the low pressure inlet 20 of the ejector 10. It is then at an intermediate pressure from the outlet 30 of the ejector 10 to the compressor 2.

In this operating mode, the third internal exchanger 26 is not used.

In FIG. 3, the system is used in the same operating mode, namely in air conditioning mode, to cool the first air flow I prior to its delivery inside the passenger compartment, without dehumidification, but in the case where the ejector 10 is not primed. In such a case, the portion of refrigerant coming from the second heat exchanger 24 borrows the bypass branch 70 to short-circuit the low pressure input 20 of the ejector 10. In this way effective cooling of the flow d is maintained. internal air I even in the absence of priming of the ejector 10.

More precisely, what differs from the previous case is that the third waterproof regulator 203 is open, preferably without operating expansion. The refrigerant portion coming from the second heat exchanger 24 thus borrows the bypass branch 70 to join the refrigerant portion having passed through the ejector 10, from the high pressure inlet 40 towards the outlet 30 of said ejector 10, said portions of refrigerant combining at the ninth junction 509.

These arrangements are such that the refrigerant is at high pressure downstream of the compressor 2 to the high pressure inlet 40 of the ejector 10, on the one hand, and to the first expansion member 201, on the other hand, then at low pressure downstream of said first expansion member 201 and of the outlet 30 of the ejector 10 to the compressor 2.

In FIG. 4, the system is used in air conditioning mode, to cool the first air flow I prior to its delivery inside the passenger compartment, with dehumidification, the ejector 10 being primed. In such a mode, at least one of the first and second internal heat exchangers 34, 24 is brought to a very low temperature. This is the second heat exchanger 24, such a result being obtained by restricting the opening of the first expansion member 201. The air flow I is therefore very cooled and dehumidified, but, in order not to cool it too much. cabin, it is heated by the third interior heat exchanger 26.

This mode differs from the mode mentioned in connection with FIG. 2 in that the refrigerant also imprints the fourth circulation line 64, said third control valve 303 being in an open configuration. The refrigerant therefore crosses said third internal heat exchanger 26 coming from the first junction point 501 and in the direction of the seventh junction point 507. The refrigerant is at high pressure in said fourth circulation line.

As illustrated in FIGS. 2 and 4, it can be seen that said system is configured so that, in the air conditioning modes, with or without dehumidification, the refrigerant feeds the second indoor heat exchanger 24 and the high pressure inlet 40 of the ejector, the low pressure input 20 of the ejector 10 being supplied from said second internal exchanger 24, this in the configurations where the ejector 10 is primed.

In FIG. 5, the system is used in heat pump mode, in which the first air flow I is heated prior to its delivery inside the passenger compartment of the motor vehicle, without dehumidification. Here, for this, the first control valve 301 and the second control valve 302 are closed. In this configuration, the fluid does not pass through the ejector 10.

Thus, the refrigerant is compressed inside the compressor 2 to be brought to a high pressure HP, then circulates to the first junction point 501. The refrigerant then borrows the fourth circulation line 64 and passes through the third valve control 303 (open position) and the third internal heat exchanger 26 inside which the refrigerant transfers calories to the air flow I intended to be blown into the passenger compartment to heat the latter prior to its delivery to the interior of the motor vehicle.

Then, the refrigerant reaches the seventh junction point 507 where it is blocked in the direction of the sixth junction point 506 by the second non-return valve 402. Thus, the refrigerant passes through the first expansion member 201 which is fully open so that no relaxation occurs there. Then the refrigerant circulates inside the second indoor heat exchanger 24, operating as a gas condenser / cooler, to ensure preheating of the air flow I intended to be blown into the passenger compartment. It continues to the eighth junction point 508. Then, due to the pressure differences involved, the refrigerant borrows the bypass branch 70 by passing through the third sealed pressure reducer 203 which is fully open so that no expansion takes place. occurs there. The refrigerant then arrives at the ninth junction point and, due to the pressure differences involved, goes to the first indoor heat exchanger 34, operating as a gas condenser / cooler, to ensure initial preheating of the flow of air I intended to be blown into the passenger compartment. The refrigerant emerges from the first internal heat exchanger 34 in the direction of the tenth junction point 510, then, the second control valve 302 being closed, passes through the fifth non-return valve 405 to reach the fifth junction point 505. Then, the refrigerant borrows the high pressure branch 52 of the internal heat exchanger 51 inside which the refrigerant transfers calories to the refrigerant present inside the low pressure branch 54. Then the refrigerant reaches the fourth point junction 504 and then crosses the second expansion member 202, operating an expansion of said fluid, then flows through the third junction point 503 then inside the external heat exchanger 50, operating as an evaporator, at the inside which the refrigerant captures calories at the second air flow E, in other words heats up on contact with the external air flow E. Then the refrigerant reaches the second junction point 502 to take the fifth circulation line 65 and pass through the fourth control valve 304 (open position) and join the eleventh junction point 511. The refrigerant then passes through the accumulator 4 inside which a any remaining liquid refrigerant is retained, then circulates inside the low pressure branch 54 of the internal heat exchanger 51 to return to the compressor 2.

These arrangements are such that the refrigerant is at high pressure HP downstream of the compressor 20 to the second expansion member 202, then at low pressure downstream of said second expansion member 202 to the compressor 2.

In FIG. 6, the refrigerant circuit is used in heat pump mode, in which the internal air flow I is heated prior to its delivery inside the passenger compartment of the motor vehicle, with dehumidification.

The circulation of the refrigerant is then identical to that of the previous figure. The difference lies in the active configuration of the first or third expansion member 201, 203, which operates an expansion on said refrigerant, said second expansion member 202 can then be in an inactive configuration by letting the refrigerant pass without subjecting it additional relaxation. In this way, the refrigerant is at high pressure downstream of the compressor 2 to the first expansion member 201 or to the third expansion member 203, then at low pressure downstream of the latter to the compressor 2.

The first indoor heat exchanger 34, or even the second indoor heat exchanger 24, then operate as an evaporator to dry the internal air flow I as already explained in relation to FIG. 4.

It can be seen that said system is configured so that a heat exchange takes place between said refrigerant and itself in said internal exchanger 51 in said heat pump mode, with or without dehumidification. This improves the performance of the device by allowing more efficient heating of the air flow I intended to be blown into the passenger compartment, without having to provide additional power to the compressor 2. Such circulation is here made possible in particular thanks to the fifth circulation line 65 and its connection with the eleventh junction point 511. As a variant, said fifth circulation line 65 may lead to the third circulation line 63 between the accumulator 4 and the internal exchanger 51, at level of the low pressure branch 54 of the latter.

In FIG. 7, the refrigerant circuit is used in heat recovery mode in which it allows, at least temporarily, to continue supplying heat to the passenger compartment via the third interior exchanger 26 because the latter produces more heat than the first indoor heat exchanger 34 produces cold. The second indoor exchanger 24 can then be used, depending on the operating conditions, to heat or cool the internal air flow I.

In these configurations, the fluid does not pass through the ejector 10 nor the external heat exchanger 50. Here, the first control valve 301 and the fourth control valve 304 are closed as well as the second sealed pressure reducer 202.

Thus, the refrigerant is compressed inside the compressor 2 to be brought to a high pressure HP, then circulates to the first junction point 501. The refrigerant then borrows the fourth circulation line 64 and passes through the third valve control 303 (open position) and the third internal heat exchanger 26 inside which the refrigerant transfers calories to the air flow I intended to be blown into the passenger compartment to heat the latter prior to its delivery to the interior of the motor vehicle. The refrigerant then reaches the seventh junction point 507. Then the refrigerant passes through the first expansion member 201 which, in a first variant, is fully open. Then the refrigerant circulates inside the second indoor heat exchanger 24, operating as a gas condenser / cooler. Downstream, it goes towards the eighth junction point 508 and takes the bypass branch 70 to pass through the third pressure reducer 203 which is active and operates an expansion on the refrigerant.

The fluid then reaches the ninth junction point 509 and then the first indoor heat exchanger 34 where it captures calories in the air flow I intended to be blown into the passenger compartment by operating as an evaporator. Indeed, said internal air flow I then comes from the passenger compartment which has been previously heated. In this way, the heating can be maintained at least temporarily in the passenger compartment while the outside heat exchanger 50 is not being used. Such a scenario is made advantageous, for example, in the event of icing of said external heat exchanger 50, rendering said external heat exchanger 50 non-operational.

The refrigerant continues to the tenth junction point 510, the second control valve 302 (open position) and the eleventh junction point 511 to pass through the accumulator 4 inside which a possible remainder of liquid refrigerant is retained. , then circulates inside the low pressure branch 54 of the internal heat exchanger 51, without heat exchange with the high pressure branch 52 to return to the compressor 2.

While remaining in heat recovery operating mode, according to a second variant in which the circulation of the fluid is identical to that of the first variant, the first expansion member 201 is active and operates an expansion of the refrigerant while the third trigger member is fully open. The first and second interior heat exchangers 34, 24 then both operate as an evaporator and capture calories in the air flow I intended to be blown into the passenger compartment.

More generally, it can be seen that said system is configured so that, in the operating modes corresponding to those illustrated in FIGS. 5 to 7, the refrigerant circulates in series in this order, from said compressor 2, through the third exchanger of internal heat 26, the second internal exchanger 24 and the first internal exchanger 34, passing through the bypass branch 70 between the second 24 and first 34 internal heat exchangers.

It can also be seen that said system is configured so that, in the operating modes corresponding to those illustrated in FIGS. 3 and 5 to 7, the refrigerant circulates from the second indoor heat exchanger 24 to the first indoor heat exchanger 34 passing through the bypass branch 70 without passing through the ejector 10 or at the very least without passing through the low pressure inlet 20 of the ejector 10.

According to another embodiment, not illustrated, the third heat exchanger 26 is absent. The fourth circulation line then only includes the third control valve 303.

According to another embodiment, not illustrated, a branch branch is mounted in parallel with the first expansion member 201 and the second internal heat exchanger 24. Said branch branch includes in series its own expansion member and a boiler which can be used to heat another fluid.

Claims (15)

1. Air conditioning system for a compartment, in particular a passenger compartment, said system being configured to be traversed by a refrigerant, said system comprising an ejector (10), said ejector (10) comprising: • a low pressure inlet (20) connected to a low pressure inlet branch (22) of the refrigerant in the ejector (10); • an outlet for the refrigerant (30), connected to an outlet branch (32) for the refrigerant from the ejector (10), said system comprising a bypass branch (70) connecting the low pressure inlet branch ( 22) to said outlet branch (32), said system being configured to selectively allow circulation of the refrigerant in the low pressure inlet branch (22) of the ejector (10) or in the bypass branch (70) . 2. System according to claim 1 wherein said bypass branch (70) comprises a regulator (203) and / or a valve, allowing selectively to open or close the circulation of the fluid in said bypass branch. 3. The system of claim 2 wherein said regulator (203) is sealed. 4. System according to any one of the preceding claims, in which said circuit comprises at least one internal heat exchanger (24, 26, 34) for carrying out a heat exchange involving the refrigerant so as to allow treatment of a flow. air to be blown inside the compartment. 5. System according to the preceding claim wherein said system comprises a first (34) and a second (24) indoor heat exchanger positioned in series, in this order, according to the direction of circulation of the air flow to be blown to the inside the compartment, 6. System according to the preceding claim wherein said system is configured so that the refrigerant circulates in said low pressure inlet branch (22) downstream of said second indoor heat exchanger (24). 7. System according to any one of claims 5 or 6 wherein said bypass branch (70) opens into said outlet branch (30) of the ejector (10) upstream of said first indoor heat exchanger (34). 8. System according to any one of claims 5 to 7 wherein said system is configured so that, in at least certain operating modes, the refrigerant circulates from the second heat exchanger (24) to the first heat exchanger (34) passing through the bypass branch (70). 9. System according to any one of claims 5 to 8 wherein said conditioning system comprises a compressor (2), supplied by said outlet branch (32) of the ejector (2) and said first indoor heat exchanger ( 34) is located on said outlet branch (32). 10. System according to the preceding claim, in which said conditioning system comprises a third internal heat exchanger (26) and, in at least certain operating modes, said system is configured to supply in series in this order, from said compressor (2 ), the third indoor heat exchanger (26), the second indoor heat exchanger (24) and the first indoor heat exchanger (34), passing through the bypass branch (70) between the second and first indoor heat exchangers (24, 34). 11. System according to any one of claims 5 to 10 wherein said circuit comprises an external heat exchanger (50) for carrying out a heat exchange between the refrigerant and an air flow circulating outside the compartment. 12. System according to the preceding claim, in which said system is configured to operate in a heat pump mode in which it draws heat from the air outside the compartment using the external heat exchanger. (50) and rejects it into the air flow to be blown inside the compartment using the or at least one of the internal heat exchangers (24, 26, 34), said system comprising in addition to a heat exchanger (51), said internal, said system being configured so that a heat exchange takes place between said refrigerant and itself in said internal exchanger (51), in cooling mode and at least in the heat pump mode. 13. System according to any one of claims 5 to 12 wherein the ejector (10) comprises a high pressure inlet (40) for the refrigerant, connected to a high pressure inlet branch (42) of refrigerant in the ejector (10). 14. System according to the preceding claim, in which said system is configured so that, in at least certain operating modes, the refrigerant feeds the second indoor heat exchanger (24) and the high pressure inlet (40) of the ejector. (10), the low pressure inlet (20) of the ejector (10) being supplied from said second internal exchanger (24). 15. An air conditioning method using the air conditioning system according to any one of the preceding claims.