FR3057343A1 - MEANS FOR MASKING FOR AIR CONDITIONING SYSTEM EXCHANGER - Google Patents

Abstract

Air conditioning system (1) for a vehicle interior, comprising: - a ventilation box, heating and / or air conditioning (6) of a flow of air sent into the passenger compartment, - a refrigerant circuit (2) within which a refrigerant fluid is circulating, comprising: o a compressor (24), ○ a first heat exchanger (20), disposed in the ventilation, heating and / or air conditioning housing (6) , ○ a second heat exchanger (22) disposed in the ventilation, heating and / or air conditioning unit (6), downstream of the first heat exchanger (20), ○ a first expansion element (30) arranged upstream the first heat exchanger (20), ○ a second expansion member (32) disposed downstream of the second heat exchanger (22), and ○ a third heat exchanger (26) disposed between the first expansion member (30) and the second expansion member (32), a coolant circuit (4) inside the which a heat transfer fluid is able to circulate, comprising at least: ○ the third heat exchanger (26), ○ a portion (86) passing through a zone of the vehicle releasing thermal energy, and ○ a low temperature radiator (84) ), characterized in that the ventilation housing, heating and / or air conditioning (6) comprises at least one member (68) preventing a flow of air flow in the first heat exchanger (20). Application to motor vehicles.

Description

® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number: 3,057,343 (to be used only for reproduction orders) (© National registration number: 16 59859

COURBEVOIE © Int Cl ⁸ : F25 B 47/00 (2017.01), F25 B 41/04, B 60 H 1/00

A1 PATENT APPLICATION

(© Filing date: 12.10.16. © Applicant (s): VALEO THERMAL SYSTEMS (© Priority: Simplified joint stock company - FR. @ Inventor (s): GOUR JOSSELIN and AOUN BER- NARD. (43) Date of public availability of the request: 13.04.18 Bulletin 18/15. (© List of documents cited in the report of 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.

($ 4) MASKING MEANS FOR AIR CONDITIONING SYSTEM EXCHANGER.

FR 3 057 343 - A1 (3 /) Air conditioning system (1) for a vehicle interior, comprising:

- a ventilation, heating and / or air conditioning unit (6) for an air flow sent into the passenger compartment,

- a refrigerant circuit (2) inside which a refrigerant is able to circulate, comprising: o a compressor (24),

O a first heat exchanger (20), placed in the ventilation, heating and / or air conditioning unit (6),

O a second heat exchanger (22), arranged in the ventilation, heating and / or air conditioning unit (6), downstream of the first heat exchanger (20),

O a first expansion member (30) disposed upstream of the first exchanger (20),

O a second expansion member (32) disposed downstream of the second heat exchanger (22), and

O a third heat exchanger (26), disposed between the first expansion member (30) and the second expansion member (32), a heat transfer fluid circuit (4) inside which a heat transfer fluid is able to circulate , including at least:

O the third heat exchanger (26),

O a portion (86) passing through an area of the vehicle releasing thermal energy, and

O a low temperature radiator (84), characterized in that the ventilation, heating and / or air conditioning unit (6) comprises at least one member (68) preventing circulation of the air flow in the first heat exchanger (20 ).

Application to motor vehicles.

62

¹ 2

Masking means for air conditioning system exchanger

The field of the present invention is that of refrigerant circuits for a heating, ventilation and / or air conditioning installation, in particular for a passenger compartment of a motor vehicle. It relates to an air conditioning system comprising a member for an exchanger included in the system.

A motor vehicle is commonly equipped with an air conditioning system for modifying a temperature of an air contained inside a passenger compartment of the motor vehicle. This system comprises at least one circuit in which a refrigerant circulates, capable of producing or absorbing heat. To do this, this circuit includes several heat exchangers for heating or cooling the air circulating in the passenger compartment, while drying this air. The drying of the air and the cooling of the air are carried out by the same heat exchanger, used as an evaporator, which acts by lowering the temperature of the air below the dew point, which has for effect of condensing the water contained in the air.

A circuit with this architecture is nevertheless fragile, and particularly at the level of the evaporator. In unfavorable climatic conditions, and in particular when the outside air temperature drops below a certain threshold, the recirculation of the air charged with humidity from the passenger compartment in the air conditioning system, in order to enhance the thermal energy of the air escaping from the passenger compartment, exposes the evaporator to icing of the water which condenses on its surface, preventing it from working and damaging it. A solution provided in the prior art consists in adding a valve to the circuit making it possible to divert the passage of the fluid from the evaporator, which inactivates it and prevents the formation and freezing of drops of water on its surface. This solution is not without its problems, in particular, because it complicates the manufacture and installation of the circuit while increasing its cost.

An object of the present invention is to provide an air conditioning system which offers a satisfactory solution to the above problem, by preventing icing of the evaporator, at a lower cost than that proposed by the solution of the prior art.

An object of the present invention is an air conditioning system comprising a ventilation, heating and / or air conditioning unit, a refrigerant circuit inside which a refrigerant is able to circulate comprising a compressor, three heat exchangers. heat, two expansion members, and a heat transfer fluid circuit inside which a heat transfer fluid is able to circulate, comprising the third heat exchanger, a portion passing through an area of the vehicle releasing thermal energy, and a low temperature radiator, the system comprising at least one member preventing circulation of the air flow in the first heat exchanger.

The air conditioning system thus arranged makes it possible to prevent icing of the heat exchanger, by limiting the passage through cold air which can freeze it, which presents a risk for users. This objective is achieved without modifying the refrigerant circuit. The absence of a diverter valve greatly simplifies the manufacturing, assembly and installation of the system.

Preferably, the expansion members are electronically controlled expansion members.

The air conditioning system advantageously comprises any at least one of the following characteristics, taken alone or in combination:

the third heat exchanger is an exchanger between a refrigerant and a heat transfer fluid. The third heat exchanger is arranged to circulate the coolant in a space adjacent to a space where the heat transfer fluid circulates, in order to allow a transfer of heat in the form of thermal energy or calories from one fluid to the other . The third heat exchanger is arranged to allow the circulation of the refrigerant fluid transverse to the direction of circulation of the heat transfer fluid so as to maximize the heat exchanges between the two fluids. The third heat exchanger can be chosen from any type of known exchanger, in particular a tube exchanger, a bundle exchanger, a spiral exchanger or a plate exchanger.

the first heat exchanger is an exchanger between an air flow circulating in the ventilation, heating and / or air conditioning unit and the refrigerant, the first heat exchanger is arranged to circulate the refrigerant in a space adjacent to a space where the air flow circulates, in order to allow heat transfer in the form of thermal energy or calories from the refrigerant to the air flow or vice versa. The first heat exchanger is arranged to allow the circulation of the refrigerant transverse to the direction of circulation of the air flow so as to maximize the heat exchanges. The first heat exchanger can be chosen from any type of known exchanger, in particular a tube exchanger, a bundle exchanger, a spiral exchanger or a plate exchanger.

the second heat exchanger is an exchanger between the air flow circulating in the ventilation, heating and / or air conditioning unit and the refrigerant, the second heat exchanger is arranged to circulate the refrigerant in a space adjacent to a space where the air flow circulates, in order to allow heat transfer in the form of thermal energy or calories from the refrigerant to the air flow or vice versa. The second heat exchanger is arranged to allow the circulation of the coolant transversely to the direction of circulation of the air flow so as to maximize the heat exchanges. The second heat exchanger can be chosen from any type of known exchanger, in particular a tube exchanger, a beam exchanger, a spiral exchanger or a plate exchanger, the refrigerant is a refrigerant or a mixture between one or several refrigerants and one or more other fluids, the refrigerant (s) being selected from authorized refrigerants and suitable for the use made of them. The refrigerant or fluids are in particular from the family of hydrochlorofluorocarbons (HCFCs), or hydrofluorocarbons (HFCs). A nonlimiting example of the refrigerant used is R134a or R1234YF. Another example of coolant is carbon dioxide, designated by the acronym R744, the heat transfer fluid is a heat transfer fluid or a mixture between one or more heat transfer fluids and one or more other fluids, the heat transfer fluid (s) being selected from heat transfer fluids authorized and suitable for the use made of them. The heat-transfer fluid (s) are in particular water, deionized water, a mixture of glycol and water or a dielectric fluid such as fluorinated hydrocarbons, the member preventing the circulation of the air flow in the first exchanger is a means of masking an inlet face of the first heat exchanger, the masking means is a movable flap between two positions, the ventilation, heating and / or air conditioning unit includes a bypass path of the first exchanger heat, the member is arranged to direct the passage of air flow by a bypass of the first heat exchanger. The bypass is either a bypass of the first heat exchanger within the ventilation, heating and / or air conditioning unit, or an additional duct arranged to bypass the first heat exchanger. The masking flap is movable in rotation or in translation. Preferably, the masking flap is movable in rotation.

the organ directs the passage of the air flow through the bypass when the temperature of the air flow is less than + 3 ° C., the temperature of the air flow being measured by a means for measuring the temperature from from the prior art, the member is chosen from a rotary shutter, a butterfly shutter and a film shutter, the compressor is an electric compressor, the refrigerant circuit includes an accumulator arranged between the first heat exchanger and the compressor, this accumulator being arranged to extract from the coolant the fraction of the coolant in the liquid state, the air conditioning system comprises an electric radiator configured to operate under a high voltage, the electric radiator being controlled to provide a surplus of thermal energy if the refrigerant circuit and the coolant circuit do not allow the air flow to be sufficiently heated to meet the needs of vehicle users , the electric radiator is arranged inside the ventilation, heating and / or air conditioning unit, the electric radiator is arranged in alignment with the second heat exchanger, downstream from the second heat exchanger. The air flow from the ventilation, heating and / or air conditioning unit passing through the second heat exchanger is thus forced to pass through the electric radiator.

The invention also relates to a vehicle equipped with an air conditioning system as defined above. More particularly, the vehicle comprises at least one electric traction chain of which at least one component is heat treated by the heat transfer fluid circuit.

The invention also relates to a method of treating an air flow intended to be sent into a passenger compartment by an air conditioning system according to the invention, during which at least one step of detection of the icing conditions of the first heat exchanger, and at least one step of blocking the circulation of the air flow through the first heat exchanger by the member. More particularly, the step of detecting the icing conditions comprises a detection of the temperature outside the vehicle, and the member blocking the circulation of the air flow through the first heat exchanger when the temperature is below -3 °. vs.

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

Figure 1 is a schematic illustration of an air conditioning system according to the invention, the system being configured in a first operating variant, Figure 2 is a schematic illustration of an air conditioning system according to l invention, the system being configured in a second operating variant, FIG. 3 is a schematic illustration of an air conditioning system according to the invention, the system being configured in a third operating variant, FIG. 4 is a schematic illustration of an air conditioning system according to the invention, the system being configured in a fourth operating variant.

It should first be noted that the figures show the invention in detail to implement the invention, said figures can of course be used to better define the invention if necessary.

In the following description, the terms upstream and downstream are used to describe the arrangement of the component with respect to the direction of circulation of the fluid considered. Likewise, the arrangement of the constituent elements of a fluid circuit is given with respect to the circulation of the fluid. An element described below as being located between two other elements does not mean that the element is physically between the other two, but that the fluid first passes through one of the other two elements, before passing through the element considered.

Referring first to FIG. 1, an example of the architecture of the air conditioning system according to the invention is seen.

The air conditioning system 1 represented comprises a coolant circuit 2 arranged for the circulation of a coolant, a heat transfer fluid circuit 4 arranged for the circulation of a coolant, and a ventilation unit, heating and / or air conditioning 6, arranged for the circulation of an air flow.

The refrigerant circuit 2, arranged for the circulation of the refrigerant, comprises a first heat exchanger 20, a second heat exchanger 22, a compressor 24, a third heat exchanger 26, an accumulator 28, a first expansion member 30 and a second expansion member 32. These elements are connected by rigid or flexible pipes 34.

The first heat exchanger 20 is a heat exchanger between the refrigerant and the air flow circulating in the ventilation, heating and / or air conditioning box 6. The first heat exchanger 20 comprises an inlet face 20a and a outlet face 20b. The outlet face 20b is the face of the first heat exchanger 20 which is arranged opposite the second heat exchanger 22. The inlet face 20a is the face opposite to the outlet face 20b. The first heat exchanger 20 is arranged to allow the circulation of air transverse to the circulation of the refrigerant, so as to maximize the heat exchange between the refrigerant and the air. More particularly, the first heat exchanger 20 is used as an evaporator arranged to cool and dry the air flow passing through the ventilation, heating and / or air conditioning box 6. The drying of the air flow is the result of the condensation of the water contained in the air flow on the surface of the evaporator.

The second heat exchanger 22 is a heat exchanger between the refrigerant and the air flow circulating in the ventilation, heating and / or air conditioning box 6. The second heat exchanger 22 is arranged to allow the circulation of the air transversely to the circulation of the refrigerant, so as to maximize the heat exchange between the refrigerant and the air. More particularly, the second heat exchanger 22 is used as a condenser arranged to heat the air flow passing through the ventilation, heating and / or air conditioning box 6.

The compressor 24 equipping the refrigerant circuit 2 is an electric compressor, arranged to increase the pressure of the refrigerant, up to a pressure of about 25 bars maximum. Such an electric compressor houses a scroll compression mechanism, driven by an electric motor also arranged in the electric compressor. This electric motor is controlled and supplied electrically by a control module configured to transform the direct electric current coming from the vehicle into alternating electric current adapted to the electric motor.

The third heat exchanger 26 is a heat exchanger between the refrigerant and the heat transfer fluid. The third heat exchanger 26 is arranged to allow the circulation of the coolant and the circulation of the heat transfer fluid adjacent, in order to allow and maximize the heat exchange between the coolant and the coolant. Depending on the situation, the refrigerant can recover calories from the heat transfer fluid, or on the contrary give it.

The refrigerant circuit 2 includes an accumulator 28, known as a "drying bottle", arranged to retain a fraction of the refrigerant in the liquid state, to prevent deterioration of the compressor 24 by fluid in the liquid state.

The refrigerant circuit 2 also includes a first expansion member 30 and a second expansion member 32. These expansion members 30, 32 are controlled, for example electronically, to pass the refrigerant from a first pressure to a second pressure lower than the first pressure. The first expansion member 30 is disposed upstream of the first heat exchanger 20, the second expansion member 32 being disposed downstream of the second heat exchanger 22.

The refrigerant is a refrigerant or a mixture of refrigerant, of the family of hydrochlorofluorocarbons (HCLC), or hydrofluorocarbons (HLC). The refrigerant may in particular be R134a or 1234YL. The refrigerant can also be carbon dioxide known by the acronym R744.

The ventilation, heating and / or air conditioning unit 6, arranged for the circulation of air towards a passenger compartment (not shown) of a vehicle (not shown), comprises an outside air inlet 60, a first air filter 62 , a recirculated air inlet 64, a second air filter 66, a member 68, the first heat exchanger 20, a mixing flap 72, the second heat exchanger 22, an electric radiator 76 configured to operate under a high voltage and an air outlet 78 to the passenger compartment.

The ventilation, heating and / or air conditioning unit 6 includes the outside air inlet 60. The outside air is supplied from outside the vehicle by an air vent which opens onto the ventilation, heating and / or air conditioning 6.

A first air filter 62 is intended to equip the outside air inlet duct 60 to prevent unwanted particles from entering the passenger compartment. The first filter can be of the type of a pollen filter, an active carbon filter or even a polyphenol filter.

The ventilation, heating and / or air conditioning unit 6 also includes a recycled air inlet 64. The recycled air is supplied from the passenger compartment of the vehicle by an air recovery circuit (not shown).

A second air filter 66 equips the recirculated air inlet duct 64. It has the same role, and can be chosen from the same filters as the first air filter 62.

The ventilation, heating and / or air conditioning unit 6 also comprises at least one movable flap 58, arranged at the confluence of the outside air inlet 60 and the recycled air inlet 64. This movable shutter 58, piloted by a temperature control unit in the passenger compartment of the vehicle, determines the source of the air sent into the air circuit, then into the passenger compartment of the vehicle. Thus, in 100% recycled air mode, the movable flap 58 is arranged opposite the outside air inlet 60 so as to close it, leaving free the inlet of recycled air 64. Conversely, in 100% outside air, the movable flap 58 is arranged opposite the recirculated air inlet 64 so as to close it, leaving the outside air inlet 60 free. The movable flap 58 can take intermediate positions to obtain a mixture between the outside air and the recycled air, and to dose this mixture. It is also possible to replace the single movable flap described above with two flaps installed respectively opposite the recycled air flow and the outdoor flow.

The ventilation, heating and / or air conditioning unit 6 comprises a member 68 and a mixing flap 72. According to an exemplary embodiment, the member 68 is arranged in front of the first heat exchanger 20. Alternatively or additionally, the member 68 is arranged behind the first heat exchanger 20. The mixing flap 72 is arranged in front of the second heat exchanger 22. Depending on its position, it defines the mixture between the flow of hot air having passed through the second heat exchanger 22 and the cold air flow having bypassed it.

The member 68 is a shutter mounted to rotate about an axis, movable between a first position allowing the passage of air through the first heat exchanger 20, and a second position preventing the passage of this same air through the first heat exchanger 20. The rotation of the member 68 is controlled by the temperature control unit in the passenger compartment of the vehicle, according to user preferences, mainly the temperature requested by the user or users of the vehicle, and climatic conditions, in particular the outside temperature, which translate into a particular mode of operation of the air flow conditioning system according to the invention. In particular, if the temperature outside the vehicle drops below a threshold temperature, the member 68 is placed in second position. In this example of the invention, the threshold temperature is for example -3 ° C. In the second position, the member 68 diverts the air to a bypass 70 of the first heat exchanger 20. The bypass 70 of the first heat exchanger 20 is a passage taken by the air flow and which directs that downstream of the first heat exchanger 20, without passing through it. The member 68 blocks the contact between the air flow and the heat exchanger 20 and thus prevents the first heat exchanger 20 from icing if the outside air temperature drops below the threshold temperature.

The mixing flap 72 is a flap similar to the member 68. The mixing flap 72 is a flap mounted to rotate about an axis, movable between a first position allowing the passage of air through the second heat exchanger 22, and a second position preventing the passage of this same air through the second heat exchanger 22. In the second position, the mixing flap 72 diverts the air towards a bypass 74 of the second heat exchanger 22. The bypass 74 of the second exchanger is a passage taken by the air flow and which directs it behind the second heat exchanger 22 without passing through it. The mixing flap 72 can take a plurality of intermediate positions between the first position and the second position. The intermediate positions are determined by the temperature control unit in order to measure the amount of air passing through the second heat exchanger 22 etο and that passing through the bypass 74 of the second exchanger, in order to obtain an air flow at the temperature requested by the users of the vehicle.

The ventilation, heating and / or air conditioning unit 6 comprises an electric radiator 76 configured to operate under high voltage, that is to say an electric radiator which has an organization which makes it suitable for operating under high voltage. By high voltage is meant a voltage greater than about 400V. This electric radiator 76 is disposed in alignment with the second heat exchanger 22, downstream thereof, that is to say between the second heat exchanger 22 and the air outlet 78 of the air circuit . The air flow passing through the second heat exchanger 22 also passes through the electric radiator 76.

The electric radiator 76 is controlled by the temperature control unit in the passenger compartment of the vehicle, and can be selectively activated to provide additional heat to the air flow passing through the electric radiator 76.

The ventilation, heating and / or air conditioning unit 6 also includes the air outlet 78 towards the passenger compartment. The air outlet 78 communicates with a distribution device making it possible to direct the air flow in dedicated areas of the passenger compartment according to the preferences of a user.

The heat transfer fluid circuit 4, arranged for the circulation of the heat transfer fluid, comprises the third heat exchanger 26, a plurality of pumps 80, a plurality of valves 82, a low temperature radiator 84 and a section passing through a vehicle engine. These elements are connected by inlet pipes 88.

The heat transfer fluid circuit 4 passes through the third heat exchanger 26. As described above, the third heat exchanger 26 is an exchanger between the coolant, a coolant, and the coolant, a heat transfer fluid.

The heat transfer fluid circuit 4 comprises a low temperature radiator 84, that is to say a radiator whose temperature of the radiator body is at most about 65 ° C. This radiator functions as a heat exchanger between the heat transfer fluid and an air which can be the air outside the vehicle or the air outside the engine, that is to say the air between the engine of the vehicle and a hood.

The heat transfer fluid circuit 4 comprises a portion 86 arranged to pass through or near an area of the vehicle releasing heat. In the case of a thermal vehicle, this zone includes the internal combustion engine of the vehicle. In the case of an electric vehicle, this zone comprises an element of an electric traction chain of the vehicle, for example the electric propulsion motor of the vehicle and / or the power components supplying said motor. In the case of a hybrid thermal / electric vehicle, this zone comprises at least one element from the internal combustion engine and / or the electric traction chain.

The heat transfer fluid circuit 4 also comprises a plurality of pumps 80 for circulating the heat transfer fluid through the heat transfer fluid circuit 4. In the variant described here, the circuit comprises two pumps 80, one arranged downstream of the third exchanger heat 26, another arranged upstream of the portion 86. Only one of the two pumps 80 is active at a given time. The pump 80 arranged upstream of the portion 86 is active when the heat transfer fluid passes through the portion 86. The pump 80 arranged downstream of the third heat exchanger 26 is active when the heat transfer fluid passes through the low temperature radiator 84.

The heat transfer fluid circuit 4 also includes a plurality of valves 82, arranged to modulate the path of the heat transfer fluid. In the variant described here, the heat transfer fluid circuit comprises three valves 82 making it possible to selectively direct the heat transfer fluid to the low temperature radiator 84 or the portion 86.

The heat transfer fluid is a heat transfer fluid, and in particular water, a mixture of glycol and water, deionized water or a dielectric fluid such as fluorinated hydrocarbons.

The system described above is used to modulate the temperature inside the passenger compartment. The system operates in at least three main modes, depending on the climatic conditions and the thermal and ventilation preferences of the vehicle users. The system is used in particular to lower the temperature of the air present in the passenger compartment, increase the temperature of the air present in the passenger compartment when the temperature of the air outside the vehicle is between 20 ° C and -3 ° C or to increase the air temperature in the passenger compartment when the air temperature outside the vehicle is below -3 ° C. An example of system configuration will be described below for each of the three modes.

If a user wishes to lower the temperature of the air flow in the passenger compartment, the system according to the invention is operated as illustrated in FIG. 2.

At the ventilation, heating and / or air conditioning unit 6, the member 68 is arranged to allow the passage of air through the first heat exchanger 20. The mixing flap 72 is arranged in front of the second heat exchanger 22, so as to prevent the passage of air through the second heat exchanger 22. The action of the second heat exchanger 22 on the air flow is thus made negligible. The air passes through the bypass 74 of the second heat exchanger without passing through the second heat exchanger 22 nor through the electric radiator 76, and exits through the air outlet 78 of the ventilation, heating and / or air conditioning unit 6.

In the refrigerant circuit 2, the refrigerant is compressed by the compressor 24 to arrive at a pressure of, for example, between 12 and 25 bars. The refrigerant passes through the second heat exchanger 22, rendered inoperative by the mixing flap 72, before passing through the third heat exchanger 26. In the third heat exchanger 26, the refrigerant transfers heat to the heat transfer fluid . The refrigerant is then expanded by a passage in the first expansion member 30, to reach a pressure of approximately 3 bars. The refrigerant then passes through the first heat exchanger 20. In the first heat exchanger 20, the refrigerant evaporates and recovers calories from the air flow passing through the ventilation, heating and / or air conditioning unit 6, thus cooling the air intended to be sent into the passenger compartment of the vehicle. At the outlet of the first heat exchanger 20, the refrigerant passes through the accumulator 28, which rids the refrigerant, which is in the gaseous state, of all traces of refrigerant in the liquid state. At the outlet of the accumulator 28, the refrigerant is directed to the compressor 24 to restart the circuit.

In the heat transfer fluid circuit 4, the heat transfer fluid is pumped by a pump 80 to pass through the third heat exchanger 26. In this third heat exchanger 26, the heat transfer fluid recovers calories from the refrigerant fluid circulating in the heat transfer circuit. refrigerant 2, which has the effect of heating the coolant and cooling the refrigerant. The heat transfer fluid then passes through the low temperature radiator 84, where the heat transfer fluid transfers its calories to the air outside the vehicle, which has the effect of cooling the heat transfer fluid. The heat transfer fluid is then directed to the pump 80 to restart the circuit.

Thus arranged, the system makes it possible to lower the temperature of the air sent into the passenger compartment of the vehicle.

If a user wishes to heat the air flow sent into the passenger compartment and the temperature of the air outside the vehicle is between 20 ° C and -3 ° C, the system is arranged as illustrated in Figures 3 and 4.

At the ventilation, heating and / or air conditioning unit 6, the member 68 is arranged to allow the passage of air through the first heat exchanger 20. The mixing flap 72 is arranged to allow the passage of the through the second heat exchanger 22. Depending on the load on the traction chain, mechanism described below, the electric radiator 76 is activated or not and the first expansion member 30 acts or not on the fluid pressure refrigerant circulating in the refrigerant circuit.

In the refrigerant circuit 2, the refrigerant is compressed by the compressor 24 to arrive at a pressure between 10 and 15 bars. The refrigerant passes through the second heat exchanger 22 where it gives calories to the air circulating in the ventilation, heating and / or air conditioning box 6. The refrigerant then passes through the second expansion member 32 to undergo a pressure drop, down to around 3 bars. The refrigerant then passes through the third heat exchanger 26 where it recovers calories from the heat transfer fluid. The refrigerant then passes through the first heat exchanger 20 where it recovers calories from the air, which has the main effect of drying the air. The refrigerant then passes through the accumulator 28, before being directed to the compressor 24 to restart the circuit.

In the heat transfer fluid circuit 4, the heat transfer fluid passes through the third heat exchanger 26. In this third heat exchanger 26, the heat transfer fluid gives calories to the refrigerant circulating in the coolant circuit 2, which has to cool the coolant and warm the coolant. The heat transfer fluid is then pumped by another pump 80 to pass through a hot zone of the engine. The heat transfer fluid is thus heated before being pumped again through the third heat exchanger 26 to restart its circuit.

Depending on the load on the powertrain, that is to say the effort provided by the engine and its components to move the vehicle, the engine can be more or less hot. This is particularly the case for an electric traction motor of the vehicle. The amount of heat released by the engine can alter the behavior of the air conditioning system 1, in particular the activation of the electric radiator 76 and the expansion operated by 30, according to two variants described below, and illustrated in FIGS. 3 and 4.

Thus, in the first variant illustrated in FIG. 3, the load on the traction chain being significant, the portion 86 of the heat transfer fluid circuit 4 passing near a component of the vehicle releasing heat recovers a significant amount of thermal energy. The portion 86 will thus yield a lot of calories to the heat transfer fluid, which transmits a large part of it to the refrigerant fluid. The refrigerant is thus heated by the heat transfer fluid. The air sent into the passenger compartment by the second exchanger 22 will thus be hot enough to reach the temperature desired by the user, and the electric heater 76 will not be activated. In this variant, the second expansion member 32 is used to lower the pressure of the coolant to an intermediate pressure, in particular 4 bars, so as not to excessively heat the coolant, which would disturb the operation of the system according to the invention. The first expansion member 30 is used to lower the pressure of the refrigerant from about 4 bars to a low pressure, in particular 3 bars.

If the engine load is low, the system has a configuration as illustrated in FIG. 4. In this configuration, the portion 86 of the heat transfer fluid circuit 4 passing through the hot component has a low temperature and does not yield sufficiently calories to the coolant to effectively heat the coolant. As the refrigerant circuit 2 does not sufficiently heat the air sent into the passenger compartment, the electric radiator 76 is then activated to give an excess of calories to the air sent to the passenger compartment. The first detent member 30 is not activated here. In particular, it has no effect on the pressure of the refrigerant. In other words, the pressure of the refrigerant flowing upstream of the first expansion member 30 is the same as that of the fluid downstream of the first expansion member 30.

Thus arranged, the system makes it possible to increase the temperature of the air sent into the passenger compartment of the vehicle.

If a user wishes to heat the air flow sent into the passenger compartment and the temperature of the air outside the vehicle is below -3 ° C, the system encounters the following problem and is arranged as follows in response to this issue.

When the temperature drops below -3 ° C, the air conditioning system can no longer use the recirculated air in the passenger compartment to exploit the thermal energy it contains to heat the air flow circulating in the ventilation, heating and / or air conditioning unit 6 without risking frosting and damaging the first heat exchanger 20. In fact, the recycled air from the passenger compartment is charged with the humidity released by the users of the vehicle, moisture which would condense on the first heat exchanger 20 in the form of water drops. These drops of water, in contact with cold air, would in turn frost. Icing of the first heat exchanger poses a risk to vehicle users, in particular by shutting down the air conditioning system, occupants being unable to adjust the temperature in the event of extreme conditions.

In order to continue to recycle the recirculated air in the passenger compartment without endangering the users of the vehicle, the passage of the humid air flow must be blocked through the first heat exchanger 20.

The configuration of the air conditioning system in this case is illustrated in FIG. L The member 68 is arranged to block the passage of air from the ventilation, heating and / or air conditioning box 6 through the first heat exchanger 20. The air flow thus passes through the bypass of the first heat exchanger 20, then passes through the second heat exchanger 22. In this way, the first heat exchanger 20 is deactivated and cannot be affected. by freezing, without diverting the flow of the coolant.

Thus arranged, the system makes it possible to increase or decrease the temperature of the air sent into the passenger compartment of the vehicle. The system according to is particularly effective in the case of a heat transfer fluid circuit configured to heat treat an electric traction chain of the vehicle.

The foregoing description clearly explains how the invention makes it possible to achieve the objectives which it has set itself and in particular to propose an air conditioning system 1 which can operate without risk of obstruction in difficult climatic conditions and the manufacturing remains easy and affordable on a large scale.

Of course, various modifications can be made by a person skilled in the art to the circulation aid device which has just been described by way of nonlimiting example, provided that at least one member is used. to divert an air flow from a heat exchanger to protect it from freezing.

In any event, the invention cannot be limited to the embodiment specifically described in this document, and extends in particular to all equivalent means and to any technically effective combination of these means.

Claims (16)

1. Air conditioning system (1) for a vehicle interior, comprising: - a ventilation, heating and / or air conditioning unit (6) for an air flow sent into the passenger compartment, - a refrigerant circuit (2) inside which a refrigerant is able to circulate, comprising: o a compressor (24), o a first heat exchanger (20), arranged in the ventilation, heating and / or air conditioning unit (6), o a second heat exchanger (22), arranged in the ventilation unit, heating and / or air conditioning (6), downstream of the first heat exchanger (20), o a first expansion member (30) disposed upstream of the first exchanger (20), o a second expansion member (32) disposed in downstream of the second heat exchanger (22), and a third heat exchanger (26), disposed between the first expansion member (30) and the second expansion member (32), - a heat transfer fluid circuit (4) inside which a heat transfer fluid is able to circulate, comprising at least: o the third heat exchanger (26), o a portion (86) passing through an area of the vehicle releasing thermal energy, and o a low temperature radiator (84), characterized in that the ventilation, heating and / or air conditioning (6) comprises at least one member (68) preventing circulation of the air flow in the first heat exchanger (20). 2. Air conditioning system (1) according to the preceding claim, wherein the third heat exchanger (26) is an exchanger between the refrigerant and the heat transfer fluid. 3. Air conditioning system (1) according to any one of the preceding claims, in which the second heat exchanger (22) is an exchanger between the air flow and the refrigerant. 4. Air conditioning system (1) according to any one of the preceding claims, in which the member (68) preventing the circulation of the air flow in the first heat exchanger (20) is a masking means (68a) of an inlet face (36) of the first heat exchanger (20). 5. Air conditioning system (1) according to the preceding claim, wherein the masking means (68a) is a flap movable in rotation between two positions. 6. Air conditioning system (1) according to any one of the preceding claims, in which the ventilation, heating and / or air conditioning unit (6) comprises a bypass path (70) of the first heat exchanger (20 ). 7. Air conditioning system (1) according to the preceding claim, wherein the member (68) is arranged to direct the passage of air flow by the bypass path (70) of the first heat exchanger (20 ). 8. Air conditioning system (1) according to the preceding claim, wherein the member (68) directs the passage of the air flow through the bypass (70) when the temperature of an air flow outside the vehicle is less than 3 ° C. 9. Air conditioning system (1) according to any one of the preceding claims, in which the member (68) is chosen from a rotary shutter, a butterfly shutter or a film shutter. 10. Air conditioning system (1) according to any one of the preceding claims, in which the compressor (24) is an electric compressor. 11. Air conditioning system (1) according to any one of the claims 10 above, wherein the refrigerant circuit (2) comprises an accumulator (28) disposed between the first heat exchanger (20) and the compressor (24). 12. Air conditioning system (1) according to any one of the claims 15 previous, the ventilation, heating and / or air conditioning unit comprises an electric radiator (76) configured to operate under a high voltage. 13. Vehicle comprising an air conditioning system (1) according to any one of the preceding claims. 14. Vehicle according to claim 13, comprising at least one electric traction chain, at least one component of which is heat treated by the heat transfer fluid circuit. 25 15. Method for treating an air flow intended to be sent into a vehicle interior by an air conditioning system according to any one of claims 1 to 12, comprising at least the following steps: a step of detecting the icing conditions of the first heat exchanger (20), and ' - A step of blocking the circulation of the air flow through the first heat exchanger (20) by the member (68). 16. Method according to the preceding claim, the step of detecting the icing conditions comprises a detection of the temperature outside the vehicle, and the member (68) blocking the circulation of the air flow through the first heat exchanger. (20) when the temperature is below -3 ° C. 1/2 3057