WO2013178685A1

WO2013178685A1 - Heating, ventilation and/or air-conditioning facility for a motor vehicle, and method for implementing such a facility

Info

Publication number: WO2013178685A1
Application number: PCT/EP2013/061078
Authority: WO
Inventors: Jean-Luc Thuez
Original assignee: Valeo Systemes Thermiques
Priority date: 2012-05-31
Filing date: 2013-05-29
Publication date: 2013-12-05
Also published as: DE112013002763T5; FR2991241A1; FR2991241B1

Abstract

The invention relates to a heating, ventilation and/or air-conditioning facility (1) for a motor vehicle, comprising: an air-conditioning loop (3) inside which a cooling fluid (FR) circulates, comprising a compressor (7), an outer heat exchanger (9), a first inner heat exchanger (11); and a secondary loop (5) inside which a heat-transfer fluid (FC) circulates, the air-conditioning loop (3) and the secondary loop (5) interacting by means of a bi-fluid heat exchanger (19). The air-conditioning loop (3) comprises at least one first switching body (15₁), a second switching body (15₂), a third switching body (15₃) and a fourth switching body (15₄), the first switching body (15₁) being arranged between the compressor (7) and the second switching body (15₂), the second switching body (15₂) being arranged between the outer heat exchanger (9) and the bi-fluid heat exchanger (19), the third switching body (15₃) being arranged between the outer heat exchanger (9) and the first inner heat exchanger (11), and the fourth switching body (15₄) being arranged between the first switching body (15₁) and the compressor (7). The invention also relates to a method for implementing such a heating, ventilation and/or air-conditioning facility (1).

Description

Heating, ventilation and / or air-conditioning system for a motor vehicle and method for implementing such an installation.

The invention is specific to the field of heating, ventilation and / or air conditioning of a motor vehicle, including an electric or hybrid motor vehicle. The invention also relates to a method of implementing such a heating, ventilation and / or air conditioning system according to various modes of operation. A motor vehicle, especially an electric or hybrid motor vehicle whose propulsion is at least partially provided by an electric motor, is commonly equipped with a heating, ventilation and / or air conditioning system to modify the aerothermal parameters of a passenger compartment of the vehicle. by delivering a flow of conditioned air inside the passenger compartment.

The heating, ventilation and / or air conditioning system may comprise an air conditioning loop, within which a refrigerant circulates, and a secondary loop, inside which a heat transfer fluid circulates. A bi-fluid heat exchanger is integrated in the air conditioning loop and the secondary loop, so that the coolant and the heat transfer fluid can exchange heat reciprocally.

In the traditional way, the air conditioning loop comprises a compressor, capable of compressing the refrigerant, at least one expansion member, adapted to allow expansion of the cooling fluid, an external heat exchanger, adapted to allow a heat exchange between the refrigerant and an ambient air flow, such as an air flow outside the vehicle, and a first indoor heat exchanger, adapted to allow a heat exchange between the refrigerant and an interior air flow, suitable for to be broadcast inside the cockpit. In addition, the air conditioning loop may comprise at least one control device, suitable for allowing an arrangement of the heating installation, ventilation and / or air conditioning according to various modes of operation.

Furthermore, the air conditioning loop may also include a refrigerant accumulator, adapted to prevent an intake of coolant in the liquid state inside the compressor.

The secondary loop comprises a second indoor heat exchanger, capable of exchanging heat with the heat transfer fluid, advantageously provided for heating the interior air flow intended to be diffused inside the passenger compartment.

However, the use of such a heating, ventilation and / or air conditioning system alternately according to a so-called "heating" mode of operation, wherein the interior air flow is reheated prior to the diffusion thereof into the The cabin of the vehicle, and according to a mode of operation called "air conditioning", in which the interior air flow is cooled prior to the diffusion of it in the passenger compartment, may prove ineffective.

In addition, such heating, ventilation and / or air conditioning systems may pose risks of icing of the external heat exchanger, for example when switching between two modes of operation of the heating, ventilation and / or air conditioning system. in particular, when the temperature of the outside air flow is relatively low or when it is desired to extract heat from the outside air flow.

In addition, such heating, ventilation and / or air conditioning systems are not suitable for diffusing the interior air flow without fogging the windshield and / or windows of the vehicle, for example when switching between two operating modes. the heating, ventilation and / or air conditioning system.

Moreover, certain known heating, ventilation and / or air-conditioning installations make it possible to ensure the cooling of electrical equipment of the vehicle, such as a battery, engine or electronic power unit. However, such heating, ventilation and / or air conditioning systems may require a large number of components to perform such a cooling function of electrical equipment.

An object of the present invention is to provide a heating, ventilation and / or air conditioning system suitable for equipping an electric or hybrid motor vehicle, offering various modes of operation, in particular a mode of operation called "air conditioning" and at least one mode of operation. operation called "heat pump" or "heating". In addition, such a heating, ventilation and / or air conditioning system is arranged to allow a so-called "defrost" operating mode, and to allow a simple way of operating a "cooling component" mode. Another object of the present invention is to propose a method of implementing such a heating, ventilation and / or air conditioning installation in order to configure the heating, ventilation and / or air-conditioning system according to various operating modes so as to simple. For this purpose, the subject of the invention is a heating, ventilation and / or air conditioning system for a motor vehicle comprising

an air conditioning loop inside which circulates a refrigerant fluid comprising a compressor, an external heat exchanger, capable of ensuring a heat exchange with an outside air flow, a first indoor heat exchanger, suitable for ensure a heat exchange with a cabin airflow intended to be diffused in a passenger compartment of the vehicle, and,

a secondary loop inside which a coolant circulates,

the air conditioning loop and the secondary loop being in interaction via a bi-fluid heat exchanger, adapted to ensure a heat exchange between the coolant and the coolant. More particularly, the air conditioning circuit comprises at least a first switching member, a second switching member, a third switching member and a fourth switching member, such that:

the first switching member is arranged between the compressor and the fourth switching member,

the second switching member is arranged between the bi-fluid heat exchanger and the external heat exchanger,

the third switching member is arranged between the external heat exchanger and the first indoor heat exchanger, and

the fourth switching member is arranged between the first switching member and the compressor. Advantageously, the external heat exchanger and / or the first indoor heat exchanger and / or the bi-fluid heat exchanger are configured to function as a condenser or as an evaporator.

In addition, the air conditioning loop includes:

a first expansion member interposed between the external heat exchanger and the second switching member, and / or

- A second expansion member interposed between the third switching member and the first indoor heat exchanger. Advantageously, the air conditioning circuit comprises at least one bypass device arranged in parallel with the first detent member and / or in parallel with the second detent member. Preferably, such a bypass device comprises a nonreturn valve. In addition, the bypass device may also include a two-way valve.

Furthermore, the air conditioning loop comprises an accumulator arranged upstream of the compressor, according to the refrigerant circulation direction. Alternatively or in addition, the secondary loop comprises a second indoor heat exchanger, adapted to ensure a heat exchange with a cabin air flow. According to such an arrangement, the first indoor heat exchanger is arranged upstream of the second indoor heat exchanger, according to the direction of flow of the cabin air flow capable of being diffused into the passenger compartment of the vehicle.

Furthermore, an additional heat exchanger is advantageously arranged downstream of the second indoor heat exchanger, according to the direction of flow of the cabin airflow capable of being diffused into the passenger compartment of the vehicle.

According to another alternative embodiment, the secondary loop comprises an auxiliary heat exchanger, adapted to ensure a heat exchange between the coolant and a component embedded in the vehicle.

The subject of the present invention is also a method of implementing a heating, ventilation and / or air-conditioning installation according to the above detailed characteristics comprising at least one step of arranging the first switching member, the second switching member, the third switching member and the fourth switching member so that, from the compressor, the coolant flows successively

in the bi-fluid heat exchanger and then in the external heat exchanger, in particular according to a mode of operation known as "air conditioning" or in a first mode of operation known as "heat pump" or "heating" or in a first or second mode of operation called "dehumidification", and / or

in the bi-fluid heat exchanger and then in the first indoor heat exchanger, in particular in a second operating mode called "heat pump" or "heating", and / or in the first indoor heat exchanger and then in the external heat exchanger, in particular in a third mode of operation known as "heat pump" or "heating", and / or

in the first indoor heat exchanger and then in the bi-fluid heat exchanger, in particular according to an operating mode known as "hot gas" or a third operating mode called "dehumidification" and / or

in the external heat exchanger and then in the bi-fluid heat exchanger, in particular according to an operating mode called "defrosting".

Moreover, according to certain modes of operation, the step of arranging the first switching member, the second switching member, the third switching member and the fourth switching member is such that:

the cooling fluid also circulates successively in the external heat exchanger and then in the first indoor heat exchanger, and / or

the refrigerant fluid is also circulated successively in the external heat exchanger and then in the bi-fluid heat exchanger.

In addition, the method of implementation may also include:

a step of deactivating the secondary loop, or

a step of activating the secondary loop. Moreover, the implementation method can also include:

- A step of opening a bypass device arranged in parallel with a first expansion member, the first expansion member being interposed between the outer heat exchanger and the second switching member and / or

- A step of opening a second bypass device arranged in parallel with a second expansion member, the second expansion member being interposed between the third member of switching and the first indoor heat exchanger.

In a complementary manner, the implementation method can also comprise:

an activation step of the additional heat exchanger.

Of course the various features, variations and / or embodiments of the present invention may be associated with each other in various combinations to the extent that they are not incompatible or exclusive of each other.

The present invention will be better understood and other characteristics and advantages will become apparent on reading the following detailed description comprising embodiments given by way of illustration with reference to the appended figures, presented by way of non-limiting examples, which may be used to complete the understanding of the present invention and the presentation of its realization and, where appropriate, to contribute to its definition, in which:

FIG. 1 is a schematic representation of a heating, ventilation and / or air-conditioning installation of a motor vehicle according to the present invention,

FIG. 2 is a schematic representation of the heating, ventilation and / or air-conditioning installation of FIG. 1 according to a mode of operation known as "air-conditioning",

FIG. 3 is a schematic representation of the heating, ventilation and / or air-conditioning installation of FIG. 1 according to a first operating mode known as "heat pump" or "heating",

FIG. 4 is a diagrammatic representation of the heating, ventilation and / or air-conditioning system of FIG. 1 according to a second operating mode called "heat pump" or "heating", FIG. 5 is a diagrammatic representation of the heating, ventilation and / or air conditioning system of FIG. 1 according to a third mode of operation known as "heat pump" or "heating", FIG. 6 is a schematic representation of the heating, ventilation and / or air-conditioning system of FIG. 1 according to a so-called "hot gas" operating mode,

FIGS. 7a and 7b are diagrammatic representations of the heating, ventilation and / or air conditioning system of FIG. 1 according to operating modes known as "defrosting",

FIG. 8 is a schematic representation of the heating, ventilation and / or air conditioning system of FIG. 1 according to a first mode of operation known as "dehumidification",

FIG. 9 is a schematic representation of the heating, ventilation and / or air conditioning system of FIG. 1 according to a second mode of operation known as "dehumidification", and

- Figure 10 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 according to a third mode of operation called "dehumidification".

It should be noted that, in the figures, the structural and / or functional elements common to the various embodiments may have the same references. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

Figure 1 is a schematic representation of a heating, ventilation and / or air conditioning system 1 of a motor vehicle according to the present invention.

Such a heating, ventilation and / or air conditioning system 1 makes it possible to modify the aerothermal parameters of a passenger compartment of a vehicle by diffusing a cabin air flow FH, or interior air flow, at a defined temperature inside. of the cockpit.

For this purpose, the heating, ventilation and / or air conditioning system 1 may comprise a blower (not shown) for circulating the interior airflow. FH from at least one air intake mouth to at least one air diffusion mouth in the passenger compartment. In particular, it may be a defrosting / defogging mouth capable of diffusing the cabin airflow FH to the windshield and / or windows of the vehicle.

According to the present invention, the heating, ventilation and / or air-conditioning system 1 comprises an air-conditioning loop 3, in which a refrigerant fluid FR circulates, and a secondary loop 5, in which circulates an heat-transfer fluid FC, such as a mixture of water and glycol.

According to the present invention, the terms "downstream", "upstream", "in series" and "in parallel" describe the position of one component relative to another, according to the direction of circulation of the refrigerant fluid FR in the loop of air conditioning 3 or in the direction of circulation of the heat transfer fluid FC in the secondary loop 5.

In addition, according to the present invention, the terms "open" and "closed" describe the state of a component allowing, respectively, to allow and / or block a passage of refrigerant FR or heat transfer fluid FC.

According to the exemplary embodiment presented, the air conditioning loop 3 comprises a compressor 7, an external heat exchanger 9, arranged to ensure a heat exchange with an outside air flow FE, a first indoor heat exchanger 11, arranged to ensure a heat exchange with the cabin air flow FH, at least a first expansion member 13i, adapted to ensure an expansion of the refrigerant fluid FR.

Preferably, the air conditioning loop 3 comprises the first expansion member 13i and a second expansion member 13 ₂ , adapted to ensure a relaxation of the refrigerant fluid FR. In addition, the air conditioning loop 3 comprises at least a first switching member 15i, for configuring the heating, ventilation and / or air conditioning system 1 in different operating modes. Preferably, the air conditioning loop 3 comprises the first switching member 15i, a second switching member 15 ₂ , a third switching member 153 and a fourth switching member 15 ₄ for configuring the heating, ventilation and / or air conditioning system 1 in different operating modes.

The different operating modes of the heating, ventilation and / or air conditioning system are, for example:

a mode of operation known as "air-conditioning", able to cool the flow of cabin air FH diffused in the passenger compartment,

a first mode of operation known as "heat pump" or "heating", able to heat the flow of cabin air FH diffused into the passenger compartment,

a second mode of operation called "heat pump" or "heating", able to dehumidify and then heat the flow of cabin air FH diffused in the passenger compartment,

a third mode of operation known as "heat pump" or "heating", able to heat the flow of cabin air FH diffused in the passenger compartment,

a first mode of operation called "dehumidification", able to dehumidify the interior airflow FH diffused into the passenger compartment,

a second mode of operation known as "dehumidification", capable of dehumidifying the interior airflow FH diffused into the cabin, and

a third mode of operation called "dehumidification", able to dehumidify the flow of cabin air FH diffused into the passenger compartment,

a mode of operation called "defrosting" capable of ensuring defrosting of the outdoor heat exchanger 9, and

a mode of operation known as "hot gas".

The different modes of operation will be described in more detail later.

The air conditioning loop 3 and the secondary loop 5 interact with each other. via a bi-fluid heat exchanger 19, arranged to ensure a heat exchange between the refrigerant fluid FR and the heat transfer fluid FC. The secondary loop 5 comprises a second indoor heat exchanger 21, arranged to provide a heat exchange with the cabin air flow FH diffused into the passenger compartment.

In addition, the secondary loop 5 may comprise a pump, not shown, adapted to ensure the circulation of the heat transfer fluid FC in the secondary loop 5.

In operation, the compressor 7 receives, at the inlet, the refrigerant fluid FR in the gaseous state, at low pressure and at low temperature, as schematically illustrated by the acronym BP in the figures. The compressor 7 makes it possible to raise the pressure and the temperature of the refrigerating fluid FR, as schematically illustrated by the symbol HP in the figures.

In addition, an accumulator 23 can be provided upstream of the compressor 7, making it possible to separate a gaseous phase and a liquid phase from the refrigerating fluid FR so as to avoid an intake of refrigerant fluid FR in the state liquid inside the compressor 7.

The external heat exchanger 9 is, for example, arranged at the front of the vehicle so as to be traversed by the outside air flow FE from the outside of the vehicle.

The outdoor heat exchanger 9 is able to function as a condenser or as an evaporator, depending on the operating mode of the heating, ventilation and / or air conditioning system 1.

As a condenser, the external heat exchanger 9 receives the fluid FR refrigerant in the form of high pressure gas and high temperature. The high pressure, high temperature gas yields heat to the outside air flow FE, passing through the outdoor heat exchanger 9, which has the effect of heating the outside air flow FE.

As an evaporator, the refrigerant FR evaporates in the outdoor heat exchanger 9. By evaporating, the refrigerating fluid FR absorbs heat from the outside air flow FE, passing through the outdoor heat exchanger 9 , which has the effect of cooling the outside air flow FE.

According to the present invention, a first expansion member 13i is advantageously arranged in series with the external heat exchanger 9. More specifically, the first expansion member 13i is interposed between the external heat exchanger 9 and the second organ switching 15 ₂ . Furthermore, the first expansion member 13i is connected to the bi-fluid heat exchanger 19, in particular via the second switching member 15 ₂ .

In particular, when the external heat exchanger 9 operates as an evaporator, the refrigerant fluid FR flows in series in the first expansion member 13i, so as to lower the pressure and the temperature of the refrigerant FR, then in the external heat exchanger 9.

Furthermore, it is possible to provide a bypass device 25 in parallel with the first expansion member 13i, so as to form a bypass so that the refrigerant fluid undergoes a prior expansion. Advantageously, the bypass device 25 is therefore able to allow or prohibit a circulation of the refrigerant fluid FR inside the first expansion member 13i, to which it is assigned.

The bypass device 25 may comprise for example a first non-return valve allowing the circulation of the refrigerant fluid FR, in one direction, and prohibiting the circulation of the refrigerant fluid FR, in the other direction.

In a variant, when the external heat exchanger 9 operates as a condenser, the refrigerant fluid FR flows in series in the external heat exchanger 9 and then in the first expansion member 13i, so as to lower the pressure and the temperature FR refrigerant after condensation or, alternatively, the refrigerant FR bypasses the first expansion member 13i before circulating in the outdoor heat exchanger 9. Alternatively or additionally, the bypass device 25 may comprise a valve two -channels whose opening is controlled so that the refrigerant bypasses the first expansion member 13i. The two-way valve can be arranged alone or in parallel with a non-return valve. The first indoor heat exchanger 11, similar to the outdoor heat exchanger 9, is able to function as a condenser or as an evaporator depending on the operating mode of the heating, ventilation and / or air conditioning system. 1. As a condenser, the first indoor heat exchanger 11 receives the refrigerant FR in the form of gas at high pressure and at high temperature. The high-pressure, high-temperature gas transfers heat to the interior airflow FH, passing through the first indoor heat exchanger 11, which has the effect of heating up the interior airflow FH that can be diffused in the room. cabin.

As an evaporator, the refrigerant FR evaporates in the first indoor heat exchanger 11. By evaporating, the refrigerating fluid FR absorbs the heat of the cabin air flow FH through the first indoor heat exchanger 11, which has the effect of cooling the flow of cabin air FH suitable for being diffused in the passenger compartment . According to the illustrated embodiment, a second expansion member 132 is arranged in series with the first indoor heat exchanger 11. The trigger is used to lower the pressure and temperature of the refrigerant FR. Advantageously, the second expansion member 132 is interposed between the third switching member 153 and the first indoor heat exchanger 11.

In particular, when the first indoor heat exchanger 11 operates as an evaporator, the refrigerant fluid FR flows in the second expansion member 132, to lower the pressure and the temperature of the refrigerant FR, before crossing the first indoor heat exchanger 11.

Alternatively, when the first indoor heat exchanger 11 operates as a condenser, the refrigerant fluid FR flows in the first indoor heat exchanger 11 and then in the second expansion member 132, so as to lower the pressure and the temperature of the fluid FR refrigerant after condensation.

According to an alternative embodiment not shown, there may be a second bypass device in parallel with the second expansion member 132, so as to form a bypass so that the refrigerant FR undergoes a prior relaxation. Advantageously, the second bypass device is therefore able to allow or prohibit a circulation of the refrigerant fluid FR inside the second expansion member 132, to which it is assigned.

The second bypass device comprises for example a check valve allowing the circulation of the refrigerant fluid FR, in one direction, and prohibiting the circulation of the refrigerant fluid FR, in the other direction. Alternatively or in addition, the second bypass device may comprise a two-way valve whose opening is controlled so that the refrigerant bypasses the second expansion member 132. The two-way valve can therefore be arranged alone or in parallel with the non-return valve.

Furthermore, the first indoor heat exchanger 11 is, according to the illustrated example, arranged upstream, in the direction of flow of the cabin airflow FH adapted to be diffused in the passenger compartment of the vehicle, the second heat exchanger internal heat 21 of the secondary loop 5.

Such an arrangement is particularly advantageous for dehumidifying the flow of cabin air FH adapted to be diffused into the passenger compartment by cooling it by passing through the first indoor heat exchanger 11 before heating it through the second indoor heat exchanger 21.

The air conditioning loop 3 furthermore comprises four switching members, respectively the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member 15 ₄ , arranged so as to be able to configure the heating, ventilation and / or air conditioning system 1 between different operating modes in a simple way. In particular, the first switching member 15i, the second switching member 15 ₂ and the third switching member 153 and the fourth switching member 15 ₄ are formed as three-way valves.

According to the present invention, the first switching member 15i is arranged in series between the compressor 7 and the fourth switching member ₄ . The first switching member 15i has a first channel and a second channel for the circulation of the refrigerant FR, the first channel and the second channel being separate. The first channel of the first switching member 15i is such that the coolant FR flows from the compressor 7 to the bi-fluid heat exchanger 19. The second channel of the first switching member 15i is such that the refrigerant fluid FR flows from the compressor 7 to the first indoor heat exchanger 11. In addition, the refrigerant fluid FR is also able to flow from the compressor 7 to the third switching member 153 when the second channel of the first switching member 15i is open.

The second switching member ₂ is arranged between the external heat exchanger 9 and the bi-fluid heat exchanger 19. The second switching member ₂ comprises a first channel and a second channel for the circulation of the refrigerant FR , the first channel and the second channel being separate.

The first channel of the second switching member 15 ₂ is such that the refrigerating fluid FR flows from the bi-fluid heat exchanger 19 to the external heat exchanger 9. The refrigerant fluid FR can also circulate in the first channel of the second 15 switching member ₂ in the other direction, namely from the outdoor heat exchanger 9 to the heat exchanger of bi-fluid heat 19. the second channel 15 of the second switching member ₂ is such that the coolant circulates FR from the bi-fluid heat exchanger 19 to the first indoor heat exchanger 11. The refrigerant fluid FR can also flow in the second channel of the second switching member ₂ in the other direction, namely the first indoor heat exchanger 11 to the bi-fluid heat exchanger 19. The third switching member 153 is arranged between the outdoor heat exchanger 9 and the first indoor heat exchanger 11. The third switching member 153 also has a first channel and a second channel for the circulation of the refrigerant FR, the first channel and the second channel being separate.

The first channel of the third switching member 153 is such that the refrigerant fluid FR flows from the outdoor heat exchanger 9 to the first indoor heat exchanger 11. The refrigerant fluid FR can also flow in the first channel of the third switching member 153 in the other direction, namely from the first indoor heat exchanger 11 to the outdoor heat exchanger 9. The second channel of the third switching 153 is such that the refrigerant fluid FR flows from the external heat exchanger 9 to a fourth switching member ₄ . The coolant FR can also flow in the second channel of the third switching member 153 in the other direction, namely from the fourth switching member ₄ to the external heat exchanger 9.

The fourth switching member ₄ is arranged between the first switching member 15i and the compressor 7. The fourth switching member ₄ also includes a first channel and a second channel for the circulation of the refrigerant FR, the first channel and the second channel. second channel being distinct.

The first channel of the fourth switching member ₄ is such that the coolant FR flows from the third switching member 153 to the compressor 7. The coolant FR can also flow in the first channel from the first indoor heat exchanger 11 to the the compressor 7. Finally, the second channel of the fourth switching member ₄ is such that the refrigerant fluid FR flows from the bi-fluid heat exchanger 19 to the compressor 7.

15i the first switching element, second switching element 15 _2, the third switching element 153 and the fourth switching member April ₁₅ allow to implement or to bypass various elements constituting the heating, ventilation and / or air conditioning 1 according to the defined operating mode. Furthermore, analogously to the external heat exchanger 9 and to the first indoor heat exchanger 11, the bi-fluid heat exchanger 19 is able to function as a condenser or as an evaporator according to the operating mode of the heating, ventilation and / or air conditioning system 1.

When the bi-fluid heat exchanger 19 operates as a condenser, the refrigerant fluid FR flows in series in the bi-fluid heat exchanger 19 in the form of hot gas which gives heat to the coolant FC. In this configuration, the secondary loop 5 then functions as a heating system. When the bi-fluid heat exchanger 19 operates as an evaporator, the cooling fluid FR, while evaporating, absorbs the heat of the coolant FC, which has the effect of cooling the coolant FC. In this configuration, the secondary loop 5 then functions as a cooling system.

Furthermore, an additional heat exchanger (not shown) may be arranged downstream of the second indoor heat exchanger 21, in the direction of flow of the cabin airflow FH adapted to be diffused in the passenger compartment of the vehicle. The additional heat exchanger may in particular be an electrical resistance heating radiator, in particular with a positive temperature coefficient.

The additional heat exchanger may, for example, be implemented to compensate for a cooling of the cabin air flow FH.

Furthermore, according to an alternative embodiment, the secondary loop 5 may comprise an auxiliary heat exchanger 29, as shown in Figure 7b, between the heat transfer fluid FC and a component embedded in the vehicle, including an electrical component of the vehicle. The auxiliary heat exchanger 29 is connected to the bi-fluid heat exchanger 19.

Figure 7b shows more particularly an auxiliary heat exchanger 29 between the coolant and a battery of the vehicle. Other components are conceivable such as an electric motor or an electronic power unit. As will be described in more detail later, the heating, ventilation and / or air conditioning system 1 can be implemented to cool such an electrical component in the operating mode called "cooling a component".

The various modes of operation of the heating, ventilation and / or air conditioning system 1 are now described. More specifically, Figures 2 to 10 are schematic representations of the heating, ventilation and / or air conditioning system 1 according to different respective modes of operation.

As a result, in the figures, it will be considered, by convention, that the dotted lines are used to define a part of the air conditioning loop 3 in which does not circulate the refrigerant FR or part of the secondary loop 5 in which ne circulates the heat transfer fluid FC, and the solid lines are used to define a part of the air conditioning loop 3 in which circulates the refrigerant fluid FR or part of the secondary loop 5 in which circulates the heat transfer fluid FC.

Figure 2 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 in the operating mode called "air conditioning". The so-called "air-conditioning" mode of operation makes it possible to condition the interior airflow FH capable of being diffused into the passenger compartment of the vehicle in order to cool it down.

For this purpose, the refrigerating fluid FR, at the outlet of the compressor 7, is first condensed in the external heat exchanger 9, functioning as a condenser, then undergoes expansion in the second expansion member 13 ₂ , before pass into the first indoor heat exchanger 11, operating as an evaporator. The cabin airflow FH adapted to be diffused into the passenger compartment through the first indoor heat exchanger 11 is thus cooled. In the so-called "air conditioning" operating mode, the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member ₄ are arranged so that the refrigerating fluid FR flows from the compressor 7 to the bi-fluid heat exchanger 19, then to the external heat exchanger 9, operating as a condenser without undergoing expansion, and to the second expansion member 132 and the first internal heat exchanger 11 , functioning as an evaporator.

In particular, the air conditioning loop 3 is configured so that:

the first channel of the first switching element 15i is opened and, preferably, the second channel of the first switching element 15i is closed,

the first channel of the second switching member ₂ is opened and, preferably, the second channel of the second switching member ₂ is closed,

the first channel of the third switching member 153 is opened and the second channel of the third switching member 153 is closed, and

the first channel of the fourth switching element ₄ is opened and, preferably, the second channel of the fourth switching element ₄ is closed.

Moreover,

the bypass device 25 is opened in parallel with the first expansion member 13i,

Passing through the external heat exchanger 9, operating as a condenser, the refrigerant fluid FR, in the gaseous state at high pressure and high temperature, gives heat to the outside air flow FE.

Then at the passage of the refrigerant FR in the second expansion member 13 ₂ , the pressure and the temperature of the refrigerant FR are lowered.

When passing through the first indoor heat exchanger 11, operating as an evaporator, the refrigerating fluid FR, while evaporating, absorbs the heat of the airflow FH passing through the first indoor heat exchanger 11. The cabin airflow FH able to be diffused into the passenger compartment passing through the first indoor heat exchanger 11 is thus cooled.

In the so-called "air-conditioning" operating mode, the secondary loop 5 is deactivated so that the heat transfer fluid FC does not circulate between the second indoor heat exchanger 21 and the bi-fluid heat exchanger 19.

Thus, the cabin airflow FH adapted to be diffused in the passenger compartment passing through the first indoor heat exchanger 11, then optionally the second indoor heat sink 21 downstream of the first indoor heat exchanger 11, does not undergo any exchange. additional thermal.

By reaching the passenger compartment of the vehicle, for example under the action of a blower not shown, the cooled cabin air flow FH reduces the air temperature of the passenger compartment.

The refrigerant FR, at the outlet of the first indoor heat exchanger 11, then returns to the compressor 7, to start a cycle again. The refrigerating fluid FR may, beforehand, undergo a new expansion, for example, when a third expansion element is arranged downstream of the first indoor heat exchanger 11. In addition, the accumulator 23, possibly arranged upstream of the compressor 7, makes it possible to avoid the admission of refrigerant fluid FR in the liquid state into the compressor 7. The compressor 7 thus receives, on admission, the refrigerant fluid FR in the gaseous state under low pressure and low temperature.

Figure 3 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 according to the first mode of operation called "heat pump" or "heating". In the first mode of operation known as "heat pump" or "heating", the refrigerating fluid FR at the outlet of the compressor 7 exchanges heat with the coolant FC in the bi-fluid heat exchanger 19, before undergoing a expansion, in the first expansion member 13i, and pass into the external heat exchanger 9, operating as an evaporator.

In the first operating mode called "heat pump", the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member ₄ are arranged so that the coolant FR flows from the compressor 7 to the bi-fluid heat exchanger 19, then to the external heat exchanger 9 through the first expansion member 13i, the external heat exchanger 9, operating as an evaporator .

In particular, the air conditioning loop 3 is configured so that:

the first channel of the first switching element 15i is opened, and, preferably, the second channel of the first switching element 15i is closed,

the first channel of the second switching member ₂ is opened, and, preferably, the second channel of the second switching member ₂ is closed and

the second channel of the third switching member 153 is opened, and, preferably, the first channel of the third switching 15 ₃ , and

the first channel of the fourth switching element ₄ is opened, and, preferably, the second channel of the fourth switching element ₄ is closed.

Moreover,

- The bypass device 25 is closed in parallel with the first expansion member 13i. The bi-fluid heat exchanger 19, operating as a condenser, thus receives at the inlet, on the one hand, the coolant FR, in the form of hot gas, and, on the other hand, the coolant FC. The refrigerating fluid FR transfers heat to the heat transfer fluid FC which circulates in the second indoor heat exchanger 21.

In the first mode of operation known as "heat pump", the secondary loop 5 is activated so that the coolant FC circulates in the secondary loop 5 between the second indoor heat exchanger 21 and the bi-fluid heat exchanger 19 , so as to allow a heat exchange between the refrigerant fluid FR and the coolant FC.

Thus, the secondary loop 5 draws heat from the air conditioning loop 3, via the bi-fluid heat exchanger 19, and then transfers the heat pulsed to the cabin air flow FH, via the second indoor heat exchanger 21. The cabin airflow FH, passing through the second indoor heat exchanger 21, is thus heated and can heat the passenger compartment of the vehicle.

The refrigerating fluid FR at the outlet of the bi-fluid heat exchanger 19, operating as a condenser, is thus subjected to a pressure and temperature-lowering relaxation, before it evaporates in the external heat exchanger 9, operating in as an evaporator. FR refrigerant, in the state gaseous at low pressure and at low temperature, circulates to the compressor 7 to start a cycle again.

By the control of the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member 15 ₄ , the heating, ventilation and / or air conditioning system 1 is therefore such that the air conditioning loop 3 and the secondary loop 5 are used to heat the cabin air flow FH prior to the diffusion inside the passenger compartment.

The bi-fluid heat exchanger 19, operating as a condenser, thus receives at the inlet, on the one hand, the coolant FR in the form of hot gas and, on the other hand, the coolant FC. The refrigerating fluid FR transfers heat to the coolant FC circulating in the second indoor heat exchanger 21 to heat the flow of cabin air FH adapted to be diffused into the passenger compartment.

According to an alternative embodiment not shown, the refrigerant fluid FR undergoes a second expansion before returning to the compressor 7. To do this, the refrigerant fluid FR at the outlet of the external heat exchanger 9 is directed to the first indoor heat exchanger 11. The second expansion occurs in the second expansion member 13 ₂ , arranged upstream of the first indoor heat exchanger 11. Thus, unlike the variant detailed above, the first channel of the third switching member 153 is opened and the second channel of the third switching member 153 is closed.

The refrigerant fluid FR thus undergoes a second expansion before entering the first indoor heat exchanger 11, operating as an evaporator, while it was inactive in the previous variant.

Moreover, the first mode of operation known as "heat pump" is a heating mode in which the cabin air flow FH is heated by the second indoor heat exchanger 21 of the secondary loop 5. It is therefore indirect heating mode, because the heating of the cabin air flow FH is performed via the heat transfer fluid FC and not directly by the refrigerant fluid FR. When the heat transfer fluid FC consists mainly of water, it is called heating mode on "water".

In addition, for the first mode of operation known as "heat pump", the cabin air flow FH is advantageously a flow of fresh air coming from outside the vehicle, as opposed to using a recycled air flow from the passenger compartment.

Figure 4 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 according to the second mode of operation called "heat pump" or "heating".

The second operating mode, called "heat pump", differs from the first operating mode, referred to as "heat pump", previously described in that the refrigerating fluid FR at the outlet of the bi-fluid heat exchanger 19 bypasses the heat exchanger. outside heat 9 and passes through the first indoor heat exchanger 11 before returning to the compressor 7.

The passage of the cooling fluid in the first indoor heat exchanger 11, operating as an evaporator, has the effect of dehumidifying the cabin airflow FH adapted to be distributed in the passenger compartment.

In the second operating mode called "heat pump", the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member ₄ are arranged so that the coolant FR flows from the compressor 7 to the bi-fluid heat exchanger 19, then undergoes a prior expansion through the second expansion member 13 ₂ , then flows to the second heat exchanger 11, operating as an evaporator, and then return to the compressor 7.

In particular, the air conditioning loop 3 is configured so that:

the second channel of the second switching member ₂ is opened and, preferably, the first channel of the second switching member ₂ is closed, and

In the second mode of operation called "heat pump", the bypass device 25 and the second switching member 15 ₂ are bypassed. Preferably, the first channel of the third switching member 153 and the second channel of the third switching member 153 are closed. In the second mode of operation known as "heat pump", the secondary loop 5 is activated so that the coolant FC circulates in the secondary loop 5 between the second indoor heat exchanger 21 and the bi-fluid heat exchanger 19 , so as to allow a heat exchange between the refrigerant fluid FR and the coolant FC.

Thus, contrary to the first mode of operation known as "heat pump", in the second mode of operation called "heat pump", the refrigerant FR, at the outlet of the bi-fluid heat exchanger 19, flows in the first internal heat exchanger 11, operating as an evaporator after having undergone expansion through the second expansion member 13 ₂ .

Preferably, in the second mode of operation called "pump to heat ", the refrigerant FR, at the outlet of the bi-fluid heat exchanger 19, does not flow towards the external heat exchanger 9.

Thus, the refrigerant fluid FR, at high pressure and at high temperature from the compressor 7, exchanges heat with the coolant FC in the bi-fluid heat exchanger 19, operating as a condenser. As a result, the refrigerant FR evaporates while absorbing the heat of the cabin air flow FH through the first indoor heat exchanger 11. The cabin airflow FH is thus cooled and thus dehumidified.

The heated heat transfer fluid FC, in the bi-fluid heat exchanger 19, returns to the second indoor heat exchanger 21 and makes it possible to heat the cabin air flow FH after the interior airflow FH has been cooled and dehumidified in the first indoor heat exchanger 11.

Figure 5 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 according to a third mode of operation called "heat pump" or "heating".

The third mode of operation called "heat pump" differs from the first operating mode called "heat pump" described above in that the secondary loop 5 is inactive, so that there is no heat exchange between FR refrigerant and FC coolant.

In the third mode of operation called "heat pump", the first indoor heat exchanger 11 operates as a condenser to provide a heating of the cabin airflow H capable of being diffused into the passenger compartment.

In the third mode of operation called "heat pump", the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member ₄ are arranged so that the refrigerant fluid FR flows from the compressor 7 to the second heat exchanger 11, functioning as a condenser, then undergoes expansion through the second expansion member 132, then flows to the heat exchanger outdoor heat 9, operating as an evaporator.

At the outlet of the external heat exchanger 9, the refrigerant FR bypasses the first expansion member 13i and flows towards the bi-fluid heat exchanger 19, and then returns to the compressor 7.

In particular, the air conditioning loop 3 is configured so that:

the second channel of the first switching element 15i is opened and, preferably, the first channel of the first switching element 15i is closed,

the first channel of the third switching member 153 is opened and, preferably, the second channel of the third switching member ₃ is closed, and

the second channel of the fourth switching element ₄ is opened and, preferably, the first channel of the fourth switching element ₄ is closed. Moreover,

- The bypass device 25 is opened in parallel with the first expansion member 13i.

In the third mode of operation called "heat pump", the secondary loop 5 is deactivated so that the heat transfer fluid FC does not circulate in the secondary loop 5 between the second indoor heat exchanger 21 and the heat exchanger 2. fluid 19, so as not to allow a heat exchange between the refrigerant FR and the heat transfer fluid FC.

Thus, the refrigerant fluid FR, at high pressure and at high temperature coming from the compressor 7, enters the first indoor heat exchanger 11 functioning as a condenser, and yields, in the first indoor heat exchanger 11, heat the cabin airflow FH adapted to be diffused in the cockpit.

Then, the refrigerating fluid FR, at the outlet of the first internal heat exchanger 11, undergoes expansion through the second expansion member 13 ₂ which lowers the temperature and the pressure of the refrigerant fluid FR, before passing into the heat exchanger outside 9, functioning as an evaporator. The refrigerating fluid FR, at the outlet of the external heat exchanger 9, passes through the bi-fluid heat exchanger 19, which has a "neutral" or inoperative behavior, that is to say without additional heat exchange, and then returns to the compressor 7 to start a cycle again.

Thus, the secondary loop 5 being inoperative, the use of the third operating mode called "heat pump" eliminates the problems associated with the heat transfer fluid circuit generally consisting mainly of water, including efficiency and performance. constant time.

In addition, in the case of a cold environment, that is to say with outside temperatures of the order of 0 ° C. to -10 ° C., the third operating mode, called "heat pump", makes it possible to avoid the risk of fogging when used at startup.

Figure 6 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 according to a mode of operation called "hot gas".

In the so-called "hot gas" operating mode, the first 15i switching, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member ₄ are arranged so that the refrigerant fluid FR flows from the compressor 7 to the first indoor heat exchanger 11, then to the bi-fluid heat exchanger 19, which behaves neutrally, and then returns to the compressor 7.

In particular, the air conditioning loop 3 is configured so that:

the second channel of the fourth switching element ₄ is opened and, preferably, the first channel of the fourth switching element ₄ is closed.

In the so-called "hot gas" operating mode, the bypass device 25 is bypassed. Preferably, the first channel of the third switching member 153 and the second channel of the third switching member 153 are closed.

In the so-called "hot gas" operating mode, the secondary loop 5 is deactivated so that the heat transfer fluid FC does not circulate in the secondary loop 5 between the second indoor heat exchanger 21 and the bi-fluid heat exchanger 19 , so as not to allow a heat exchange between the refrigerant FR and the heat transfer fluid FC. Thus, the refrigerant fluid FR, at high pressure and at high temperature at the outlet of the compressor 7, enters the first indoor heat exchanger 11, functioning as a condenser, and gives way to the interior airflow FH suitable for to be broadcast in the cockpit.

As a result, the refrigerant FR, at the outlet of the first indoor heat exchanger 11, undergoes expansion through the second expansion member 13 ₂ , and passes through the bi-fluid heat exchanger 19 without undergoing heat exchange, before returning to the compressor 7 to start a cycle again.

In the so-called "hot gas" operating mode, the refrigerant fluid FR, at high pressure and at high temperature, directly supplies the first indoor heat exchanger 11 for heating the flow of cabin air FH therethrough.

Such a mode of operation called "hot gas" is preferably used at the start of the vehicle, to ensure the heating of the cabin air flow FH when the temperatures are very low, for example of the order of -15 ° C to - 7 ° C.

Figures 7a and 7b are schematic representations of the heating, ventilation and / or air conditioning system of Figure 1 according to operating modes called "defrost".

To do this, the refrigerating fluid FR, at the outlet of the compressor 7, passes through the external heat exchanger 9, functioning as a condenser, before passing into the bi-fluid heat exchanger 19, functioning as a 'evaporator.

In addition, the secondary loop 5 is activated. Thus, the bi-fluid heat exchanger 19, operating as an evaporator, makes it possible to ensure the cooling of the heat transfer fluid FC circulating in the secondary loop 5.

In the so-called "defrosting" operating modes, the first switching member 15i, the second switching member 15 ₂ , the third member 153 and the fourth switching member ₄ are arranged so that the refrigerant fluid FR flows from the compressor 7 to the external heat exchanger 9, operating as a condenser, then in the first expansion member 13i, to the bi-fluid heat exchanger 19, operating as an evaporator.

In particular, the air conditioning loop 3 is configured so that:

the second channel of the third switching member 153 is opened and, preferably, the first channel of the third switching member ₃ is closed, and

Moreover,

- The bypass device 25 is closed in parallel with the first expansion member 13i. In the so-called "defrosting" operating mode, the secondary loop is activated 5 so that the coolant FC circulates in the secondary loop 5 between the second indoor heat exchanger 21 and the bi-fluid heat exchanger 19, to ensure a heat exchange between the heat transfer fluid FC and the refrigerant fluid FR in the bi-fluid exchanger 19, operating as an evaporator, so as to cool the coolant FC. Thus, by circulating in the external heat exchanger 9, functioning as a condenser, the refrigerant fluid FR, in the gaseous state at high pressure and at high temperature, gives heat to the external air flow FE. Then at the passage of the refrigerant fluid FR in the first expansion member 13i, the pressure and the temperature of the refrigerant fluid FR are lowered before circulating in the bi-fluid heat exchanger 19, operating as an evaporator.

During the passage of the refrigerant fluid FR in the bi-fluid heat exchanger 19, operating as an evaporator, the cooling fluid FR evaporating absorbs the heat of the coolant FC. Thus, the calories are drawn from the heat transfer fluid FC, comprising for example a mixture of water and glycol. The heat transfer fluid FC thus cooled returns to the second indoor heat exchanger 21. The cabin airflow FH capable of being diffused into the passenger compartment passing through the indoor heat exchanger 21 is thus cooled.

Moreover, according to an alternative embodiment shown in FIG. 7b, it is possible to have in the secondary loop 5 an auxiliary heat exchanger 29 to ensure a heat exchange between the heat transfer fluid FC and a component of the vehicle, such as a battery for example. The auxiliary heat exchanger 29 is, according to this alternative, connected to the bi-fluid heat exchanger 19. Preferably, but not exclusively, the second indoor heat exchanger 21 is no longer biased.

Thus, the heat transfer fluid FC circulating between the auxiliary heat exchanger 29 and the bi-fluid heat exchanger 19 is cooled by heat exchange with the refrigerant fluid FR in the bi-fluid heat exchanger 19. The heat transfer fluid FC cooled allows to cool the vehicle component.

In such a configuration, the operating mode called "defrosting" is also a mode of operation called "cooling a component".

In the so-called "defrosting" operating mode, the additional heat exchanger, not shown, for example an electric resistance heating radiator, in particular with a positive temperature coefficient, arranged downstream of the second indoor heat exchanger can advantageously be used. 21, so as to compensate for the discomfort generated by the cooling of the heat transfer fluid FC and / or the crossing of the second indoor heat exchanger 21 and to heat the flow of cabin air FH able to be diffused into the passenger compartment.

In addition, for the operating mode called "defrosting", the cabin airflow FH is advantageously a recycled air stream coming from the passenger compartment, as opposed to the use of an air flow. charges from outside the vehicle.

Figure 8 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 according to a first mode of operation called "dehumidification". The first mode of operation called "dehumidification" dehumidifies the cabin airflow FH able to be diffused into the cabin by cooling it before being reheated.

In the first mode of operation called "dehumidification", the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member ₄ are arranged so that the refrigerating fluid FR circulates. from the compressor 7 to the bi-fluid heat exchanger 19, functioning as a condenser, bypassing the first expansion member 13i, then undergoes expansion through the second expansion member 13 ₂ , then flows into the second heat exchanger 11, operating as an evaporator. In particular, the air conditioning loop 3 is configured so that:

the first channel of the second switching member 152 is opened and, preferably, the second channel of the second switching member 152 is closed,

the first channel of the third switching member 153 is opened, and, preferably, the second channel of the third switching member 153 is closed, and

Moreover,

- The bypass device 25 is opened in parallel with the first expansion member 13i. In the first mode of operation called "dehumidification", the secondary loop 5 is activated so that the coolant FC circulates in the secondary loop 5 between the second indoor heat exchanger 21 and the bi-fluid heat exchanger 19, of to allow a heat exchange between the refrigerant FR and the heat transfer fluid FC.

Thus, the refrigerant fluid FR, at high pressure and at high temperature at the outlet of the compressor 7, enters the bi-fluid heat exchanger 19, functioning as a condenser, and gives up heat to the heat transfer fluid FC, allowing the warming the cabin airflow FH adapted to be diffused in the cabin at the crossing of the second indoor heat exchanger 21.

As a result, the refrigerant fluid FR then circulates in the heat exchanger outside 9, also operating as a condenser, without prior expansion, and undergoes expansion through the second expansion member 13 ₂ which lowers the pressure and the temperature of the refrigerant FR, and then flows into the first indoor heat exchanger 11, functioning as an evaporator, so that the cabin air flow FH is cooled and dehumidified before being heated in the second indoor heat exchanger 21. Finally, the refrigerant fluid FR can then return to the compressor 7 to restart a refrigerant cycle. Figure 9 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 according to the second mode of operation called "dehumidification".

In the second mode of operation called "dehumidification", the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member ₄ are arranged so that the refrigerating fluid FR circulates. from the compressor 7 to the bi-fluid heat exchanger 19, then to the external heat exchanger 9, operating as an evaporator, passing through the first expansion member 13i, then to the first indoor heat exchanger 11, operating as an evaporator, passing through the second expansion member 132.

In particular, the air conditioning loop 3 is configured so that:

the first channel of the first switching element 15i is opened and, preferably, the second channel of the first switching element 15i is closed

the first channel of the third switching member 153 is opened and, preferably, the second channel of the third switching 153, and

Moreover,

- The bypass device 25 is closed in parallel with the first expansion member 13i. In the second mode of operation called "dehumidification", the secondary loop 5 is activated so that the coolant FC circulates in the secondary loop 5 between the second indoor heat exchanger 21 and the bi-fluid heat exchanger 19, operating as a condenser, so as to allow heat exchange between the refrigerant FR and the heat transfer fluid FC.

Such an arrangement therefore makes it possible to implement two detents in series. The external heat exchanger 9, downstream of the first expansion member 13i, and the first indoor heat exchanger 11, downstream of the second expansion member 13 ₂ , therefore work at different pressure levels.

Thus, the refrigerant fluid FR, at high pressure and at high temperature at the outlet of the compressor 7, yields, in the bi-fluid heat exchanger 19, heat to the coolant FC, for heating the air flow cabin FH adapted to be diffused in the cabin at the crossing of the second indoor heat exchanger 21.

As a result, the refrigerant FR then undergoes a first expansion through the first expansion member 13i which lowers the temperature and the pressure of the refrigerant FR, then passes through the external heat exchanger 9, operating as an evaporator, then undergoes a second expansion through the second expansion member 13 ₂ which further decreases the pressure and the refrigerant temperature FR, before passing through the first indoor heat exchanger 11, operating as an evaporator. The coolant FR, at the outlet of the first indoor heat exchanger 11, can then return to the compressor 7 to restart a cycle.

The flow of cabin air FH through the first indoor heat exchanger 11 is cooled and dehumidified before passing through the second indoor heat exchanger 21, to be heated, before being distributed in the passenger compartment.

Figure 10 is a schematic representation of the heating, ventilation and / or air conditioning system of Figure 1 according to a third mode of operation called "dehumidification". The third mode of operation called "dehumidification" differs from the first mode of operation called "dehumidification" in that it is a reverse dehumidification. Indeed, in the third mode of operation called "dehumidification", the cabin airflow FH adapted to be distributed in the passenger compartment is first heated before being cooled to dehumidify the cabin airflow FH.

In the third mode of operation called "dehumidification", the first switching member 15i, the second switching member 15 ₂ , the third switching member 153 and the fourth switching member ₄ are arranged so that the refrigerating fluid FR circulates. from the compressor 7 to the first indoor heat exchanger 11, functioning as a condenser, then undergoes expansion through the second expansion member 13 ₂ and then flows into the bi-fluid heat exchanger 19, functioning as a evaporator.

In particular, the air conditioning loop 3 is configured so that:

the second channel of the first switching element 15i is opened and, preferentially, the first channel of the first switching member 15i is closed,

the second channel of the fourth switching element ₄ is opened and, preferably, the first channel of the fourth switching element ₄ is closed. In the third mode of operation called "dehumidification", the bypass device 25 is bypassed. Preferably, the first channel of the third switching member 153 and the second channel of the third switching member 153 are closed. Thus, the refrigerant fluid FR, at high pressure and at high temperature at the outlet of the compressor 7, circulates in the first indoor heat exchanger 11, functioning as a condenser, and gives up heat to the interior airflow FH passing through the first indoor heat exchanger 11 and adapted to be distributed in the passenger compartment.

As a result, the refrigerating fluid FR undergoes expansion through the second expansion member 13 ₂ which lowers the pressure and the temperature of the refrigerant fluid FR and then flows into the bi-fluid heat exchanger 19, operating as an evaporator to cool the heat transfer fluid FC flowing to the second indoor heat exchanger 21 downstream of the first indoor heat exchanger 11.

In the third mode of operation called "dehumidification", the secondary loop 5 is activated so that the coolant FC circulates in the secondary loop 5 between the second indoor heat exchanger 21 and the bi-fluid heat exchanger 19, of to allow a heat exchange between the refrigerant FR and the heat transfer fluid FC. The interior airflow FH passing through the second indoor heat exchanger 21 is cooled and thus dehumidified after being heated through the first indoor heat exchanger 11.

It is therefore understood that the arrangement and control, simultaneous and / or alternating, 15i of the first switching element, second switching element 15 _2, the third switching element 153 and the fourth switching member April ₁₅ allows to easily change the mode of operation of the air conditioning loop 3, using fewer components than in the arrangements of the prior art.

Throughout the description of the present invention in connection with Figures 1 to 10, the first expansion member 13i and the bypass device 25 have been described as components of the air conditioning loop 3 separate. However, alternatively, the first detent member 13i and the bypass device 25 may be combined in a single detent / bypass member to form an integrated system. Of course, the invention is not limited to the embodiments described above and provided solely by way of example. It encompasses various modifications, alternative forms and other variants that may be considered by those skilled in the art in the context of the present invention and in particular any combination of the different modes of operation described above, which can be taken separately or in combination.

Claims

1. Heating, ventilation and/or air conditioning installation (1) for motor vehicles, comprising

- an air conditioning loop (3) inside which circulates a refrigerant fluid (FR) comprising a compressor (7), an external heat exchanger (9), capable of ensuring an exchange of heat with a flow of exterior air (FE), a first interior heat exchanger (11), capable of ensuring an exchange of heat with a flow of passenger compartment air (FH) intended to be distributed in a passenger compartment of the vehicle, and,

- a secondary loop (5) inside which a heat transfer fluid (FC) circulates,

the air conditioning loop (3) and the secondary loop (5) being in interaction via a bi-fluid heat exchanger (19), capable of ensuring heat exchange between the refrigerant fluid (FR) and the heat transfer fluid (FC),

characterized in that the air conditioning loop (3) comprises at least a first switching member (15i), a second switching member (15 ₂ ), a third switching member (153) and a fourth switching member (15 ₄ ),

- the first switching member (15i) being arranged between the compressor (7) and the fourth switching member (15 ₄ ),

- the second switching member (15 ₂ ) being arranged between the bi-fluid heat exchanger (19) and the external heat exchanger (9),

- the third switching member (153) being arranged between the exterior heat exchanger (9) and the first interior heat exchanger (11), and

- the fourth switching member (15 ₄ ) being arranged between the first switching member (15i) and the compressor (7).

2. Heating, ventilation and/or air conditioning installation (1) according to claim 1, in which the exterior heat exchanger (9) and/or the first interior heat exchanger (11) and/or the heat exchanger bi-fluid (19) are configured to operate as a condenser or as an evaporator.

3. Heating, ventilation and/or air conditioning installation (1) according to any one of the preceding claims, in which the air conditioning loop (3) comprises an expansion member, called the first expansion member (13i), interposed between the the external heat exchanger (9) and the second switching member (15 ₂ ).

4. Heating, ventilation and/or air conditioning installation (1) according to any one of the preceding claims, in which the air conditioning loop (3) comprises an expansion member, called a second expansion member (13 ₂ ), interposed between the third switching member (153) and the first interior heat exchanger (11).

Heating, ventilation and/or air conditioning installation (1) according to one of the

claims 3 or 4, in which the air conditioning loop (3) comprises at least one bypass device (25) arranged in parallel with the expansion member (13i, 13 ₂ ).

Installation of heating, ventilation and/or air conditioning (1) according to one

any of the preceding claims, in which the air conditioning loop (3) comprises an accumulator (23) arranged upstream of the compressor (7).

7. Heating, ventilation and/or air conditioning installation (1) according to any one of the preceding claims, in which the secondary loop (5) comprises a second interior heat exchanger (21), capable of ensuring heat exchange with cabin air flow (FH).

8. Heating, ventilation and/or air conditioning installation (1) according to claim 7, in which the first indoor heat exchanger (11) is arranged upstream of the second indoor heat exchanger (21).

9. Heating, ventilation and/or air conditioning installation (1) according to claim 7 or 8, in which an additional heat exchanger is arranged downstream of the second interior heat exchanger (21).

10. Heating, ventilation and/or air conditioning installation (1) according to any one of the preceding claims, in which the secondary loop (5) comprises an auxiliary heat exchanger (29), capable of ensuring an exchange of heat between the heat transfer fluid (FC) and a component embedded in the vehicle.

1 1 . Method for implementing a heating, ventilation and/or air conditioning installation (1) according to any one of claims 1 to 10, characterized in that it comprises at least one step of arranging the first switching member (15i), the second switching member (15 ₂ ), the third switching member (153) and the fourth switching member (15 ₄ ) so that, from the compressor (7), the refrigerant fluid (FR) circulates successively in the bi-fluid heat exchanger (19) then in the external heat exchanger (9).

12. Implementation method according to claim 11, in which the refrigerant fluid (FR) circulates successively in the exterior heat exchanger (9) then in the first interior heat exchanger (11).

13. Method for implementing a heating, ventilation and/or air conditioning installation (1) according to any one of claims 1 to 10, characterized in that it comprises at least one step of arranging the first member switching (15i), of the second switching member (15 ₂ ), the third switching member (153) and the fourth switching member (15 ₄ ) so that, from the compressor (7), the refrigerant fluid (FR) circulates successively in the bi-heat exchanger fluid (19) then into the first interior heat exchanger (11).

14. Method for implementing a heating, ventilation and/or air conditioning installation (1) according to any one of claims 1 to 10, characterized in that it comprises at least one step of arranging the first member switching member (15i), the second switching member (15 ₂ ), the third switching member (153) and the fourth switching member (15 ₄ ) so that, from the compressor (7), the refrigerant fluid (FR ) circulates successively in the first interior heat exchanger (11) then in the exterior heat exchanger (9).

15. Implementation method according to claim 14, in which the refrigerant fluid (FR) circulates successively in the external heat exchanger (9) then in the dual-fluid heat exchanger (19).

16. Method for implementing a heating, ventilation and/or air conditioning installation (1) according to any one of claims 1 to 10, characterized in that it comprises at least one step of arranging the first member switching member (15i), the second switching member (15 ₂ ), the third switching member (153) and the fourth switching member (15 ₄ ) so that, from the compressor (7), the refrigerant fluid (FR ) circulates successively in the first interior heat exchanger (11) then in the bi-fluid heat exchanger (19).

17. Method for implementing a heating, ventilation and/or air conditioning installation (1) according to any one of claims 1 to 10, characterized in that it comprises at least one step of arranging the first member switching member (15i), the second switching member (15 ₂ ), the third switching member (153) and the fourth switching member switching (15 ₄ ) so that, from the compressor (7), the refrigerant fluid (FR) circulates successively in the external heat exchanger (9) then in the bi-fluid heat exchanger (19).

18. Implementation method according to any one of claims 11 to 17, characterized in that it comprises a step of deactivation of the secondary loop (5).

19. Implementation method according to any one of claims 11 to 17, characterized in that it comprises a step of activating the secondary loop (5).

20. Implementation method according to any one of claims 11 to 19, characterized in that it comprises a step of opening a bypass device (25) arranged in parallel with a first expansion member ( 13i), the first expansion member (13i) being interposed between the external heat exchanger (9) and the second switching member (15 ₂ ).

21. Implementation method according to any one of claims 11 to 20, characterized in that it comprises a step of activating the additional heat exchanger.