FR3070315A1 - VEHICLE EQUIPPED WITH A CLIMATE GROUP AND AIR CONDITIONING METHOD - Google Patents

Abstract

The invention relates to a vehicle equipped with an air conditioning unit (12) comprising a main air circuit comprising a first air intake (A) to be air-conditioned, a blower (2), an evaporator (4), a heater (7), a shutter (6) for distribution that allows the air from the evaporator (4) to pass or not through the heater (7), a conditioned air outlet (S) and its means of shutter (9, 9 ', 9' '), a flap (1) recirculation which selects the composition of the air sucked by the first air intake (A), characterized in that it comprises a circuit additional air (13) comprising a second intake (A ') of air to be conditioned, an additional blower (2'), an air outlet (S ') opening into the main circuit between the heater (7) and the evaporator (4), a shutter (14) for controlling the air outlet (S '), the shutter (6) for distribution also allowing the air coming from the additional air circuit (13) to pass or not by the air heater (7).

Description

VEHICLE EQUIPPED WITH AN AIR CONDITIONING GROUP AND AIR CONDITIONING METHOD

The present invention relates to air conditioning. The invention relates more particularly to a vehicle equipped with an air conditioning unit and an air conditioning control method.

The environmental context (regulation of polluting emissions, greenhouse gases and outdoor noise levels) guides the current trend towards the development of vehicles that are always less emitting CO ₂ and pollutants. As such, the trend is directed on the one hand towards the reduction of the average speeds of rotation of the thermal engine which consequently induces a reduction of the rotation speed of the coolant pump and therefore of its flow in the heat transfer circuit. . On the other hand, the trend is also moving towards technologies such as for example the recirculation circuit or an exhaust manifold for burnt gases integrated into the cylinder head, adding more heat flux to dissipate from the heat engine and its circuit. coolant, through the radiator.

In addition, vehicles often have an air conditioning unit, also known as HVAC (acronym for the English expression Heating, Ventilation, and Air Conditioning). The role of this system is to purify, cool, heat, regulate the temperature, ventilate and dehumidify the air entering the passenger compartment, based on input data provided by the operator and various sensors.

Such an air conditioning unit, known for example from document EP2847013A1 is illustrated diagrammatically in FIG. 1. This air conditioning unit comprises a recirculation flap 1, according to the vehicle equipment actuated manually by the occupants of the vehicle and / or automatically by the function of piloting and regulating the quality of the air in the passenger compartment, which selects the composition of the air sucked in by the blower 2, between a source entirely from the passenger compartment, H or from the outside E (in this case, via an air filter 3 disposed upstream of the recirculation flap 1, arranged, as illustrated in FIG. 1, perpendicular to the axis of the air duct conveying air from the outside E. According to a alternative, the air filter 3 is placed at an angle in this air duct, so as to create an angle of for example 20 to 60 ° with the axis of this air duct, in order to increase the filtration surface air in p rovenance from the outside E without penalizing the air permeability of the outside air duct upstream of the recirculation flap 1. According to this state of the art, the evaporator 4 of the refrigerant circuit is installed downstream and immediately at the outlet of the blower 2 whatever the operating mode of the air conditioning unit and the refrigerant circuit (not shown) to which the Evaporator 4. According to this state of the art, the air to be conditioned systematically passes through the evaporator 4, even if the refrigeration is inactive or if this crossing is not necessary (air pressure drops from the evaporator 4 impacting the power consumption of blower 2 to overcome it). At the immediate downstream side of the evaporator 4 is located in the local or global lower part a conduit 5 allowing the condensates produced during the operation of the refrigeration to be evacuated outside the vehicle so that they do not fall to the interior of the passenger compartment. A second distribution flap 6 allows the air from the evaporator 4 to pass or not through the air heater 7 supplied with coolant from the heat engine, via a bypass passage. Finally, a last series of distribution flaps 9, 9 ', 9 ”allows the air from the mixing chamber 8, at the outlet of the evaporator 4 and the air heater 7 to be directed towards the different targeted zones in the passenger compartment, or to close off all the exits, so that the air distribution in the passenger compartment H from the air conditioning unit is completely cut off: lower part of the passenger compartment, Hi, upper part of the passenger compartment , Hs, glazed areas to be defrosted / demisted, Hv.

There are also dual zone air conditioning units (“dual zone” in English), illustrated diagrammatically in FIG. 2. In this FIG. 2, the elements similar to the air conditioning unit of FIG. 1 have the same reference. Such an air conditioning unit makes it possible to differentiate according to the targeted zones the temperature of the air supplied to the passenger compartment H. As soon as the blower 2 exits, the air admitted into the air conditioning unit is dissociated into two flows circulating in parallel in two conduits 10, 10 'and passing entirely through the evaporator 4. Two flaps 11, 11' arranged downstream of the evaporator 4 in each conduit 10, 10 'make it possible to bypass and / or pass through the air heater 7, in whole or in part. Flaps 17, 17 ’are also provided downstream of the air heater 7 making it possible to cut off all air circulation through the air conditioning unit towards the passenger compartment H.

These architectures above faithful to the state of the art pose the three problems described below.

In certain operating modes, the architecture of these air conditioning units requires systematically to pass through the evaporator 4 when it is not operating because the refrigeration is inactive. This generates an unnecessary additional aerodynamic resistance opposing the air flow, which must be compensated by an adaptation of the control of the blower 2 which increases the electric consumption.

This is for example the case:

- when there is a significant demand for air heating by the air heater 7 without there being any need to dehumidify the air admitted to the air conditioning unit beforehand, as illustrated in FIG. 3.

- in the economic operation phase of the air conditioning of the passenger compartment, illustrated in FIG. 4. In this mode, the operator selects an “all cold” setting but without activating the refrigeration either by selecting this economic mode or by not activating the refrigeration. The entire flow of filtered air admitted at outside ambient temperature does not pass through the air heater 7 before entering the passenger compartment.

Another mode of operation of the air conditioning unit is implemented to ensure the thermal regulation of the passenger air, such that the refrigeration and the heating operate at the same time. Figures 5 and 6 illustrate this operating mode, respectively in the case of a single air conditioning group and a dual zone air conditioning group.

Thus, in particular when the dehumidification of the air admitted into the air conditioning unit is not necessary, the entire air flow passes through the evaporator 4 which cools it before part of this air flow does either directed, by the position taken by the associated distribution flap, through the air heater 7. Consequently, in this operating mode, the architecture of the air conditioning group imposes a pre-cooling through the passage of the evaporator 4 of the admitted air, before it is reheated by passing through the air heater 7. This is doubly problematic:

- When the engine is not yet hot enough to supply the air heater 7 with the coolant at sufficient temperature, the air leaving the air heater 7 is then not hot enough to regulate the air entering the passenger compartment at the desired temperature, which may then require the use of additional energy-consuming heating elements such as for example a heating resistor on the air and / or on the coolant, a burner;

- This also slows down the temperature rise of the heat engine since its coolant is cooled through the air heater by air at the evaporator outlet 4 potentially at a temperature below room temperature.

Finally, in certain life phases such that the air conditioning unit is called upon to meet a significant demand for refrigeration, the air heater 7, although always traversed by the coolant leaving the heat engine, is then completely bypassed by the air passing through the air conditioning unit so as not to unnecessarily heat the air supplied to the passenger compartment. However in these life situations where the outside is at high temperature, the heat engine may require significant cooling that the radiator located on the front of the vehicle may not completely satisfy. Indeed, these life situations generally correspond to:

• poor ventilation of the radiator (low speed vehicle: traffic jams, city, mountain, etc.) despite the operation of the motor-fan unit, • loaded driving, towing, steep slopes, etc.

with aggravating stresses, • on the one hand, a high intake air temperature, (poor ventilation of the charge air cooler, thermal environment under the hood heating the intake air and increasing the thermal power to be dissipated compared to the mechanical power available at the crankshaft), • and on the other hand the full power operation of the refrigeration, the compressor of which is most often driven by the heat engine, thus applying an additional load to it, and the condenser of which conventionally disposed upstream of the radiator (in the direction of the flow of outside air through the grille of the vehicle and the cooling module) dissipates heat to the outside air, which will then pass through the radiator.

These life situations generally lead to a reduction in vehicle benefits, in particular:

- progressive reduction of the mechanical power delivered by the heat engine, to reduce the thermal stress, resulting in a reduction in the maximum speed then achievable by the vehicle according to its load;

- load shedding of the refrigeration which can go as far as cutting it off, to relieve on the one hand the heat engine of the supply of additional torque dedicated to the drive of the compressor and, via the drive of the alternator, to the operation of the group motor fan, and on the other hand the radiator for cooling the thermal power dissipated to the outside air by the condenser.

An object of the present invention is therefore to improve the aforementioned situations.

To achieve this objective, there is provided according to the invention a vehicle equipped with a heat engine and its liquid cooling circuit, an air conditioning unit comprising:

- a main air circuit comprising from upstream to downstream:

- a first intake of air to be conditioned,

- an air blower,

- an evaporator of a refrigerant circuit,

- an air heater connected to the cooling circuit of the heat engine,

- a distribution flap which allows the air from the evaporator (4) to pass or not through the air heater,

- an air conditioning outlet to a passenger compartment of the vehicle,

- means for shutting off the air conditioning outlet to the passenger compartment,

- a recirculation flap which selects the composition of the air drawn in by the first air intake, between a source from the passenger compartment or from the outside or from a mixture of air coming from the passenger compartment and from the exterior, characterized in that it comprises an additional air circuit comprising:

- a second intake of air to be conditioned,

- an additional blower,

- an air outlet which opens into the main circuit between the air heater and the evaporator, downstream of the distribution flap,

- a control flap for the air outlet, and in that the distribution flap also allows the air from the additional air circuit to pass or not through the air heater.

The technical effect is to have an architecture which makes it possible not to systematically cross the evaporator, in particular when the latter is not active.

Various additional characteristics can be provided, alone or in combination:

According to one embodiment, the second air intake is arranged relative to the first air intake so that when the recirculation flap selects for the first air intake a composition of air sucked entirely from the passenger compartment , the second air intake also receives all air from the outside.

According to another embodiment, the second air intake is arranged relative to the first air intake so that:

- when the recirculation flap selects for the first air intake a composition of air aspirated entirely from the passenger compartment, the second air intake also receives air entirely from the passenger compartment ,

when the recirculation shutter selects for the first air intake a composition of air drawn in entirely from the outside, the second air intake also receives air entirely coming from the outside, and in that the second air intake comprises an additional inlet flap, placed relative to the direction of entry of air into the air conditioning unit, downstream of the recirculation flap.

According to one embodiment, the air admitted into the main circuit of the air conditioning unit is dissociated into two flows circulating in parallel in two ducts, passing entirely through the evaporator, two flaps arranged downstream of the evaporator in each duct make it possible to bypass and / or pass through the air heater, in whole or in part.

According to one embodiment, the air conditioning unit comprises an air delivery duct at the start of the main air circuit, between the air conditioning outlet and the air heater and a flap for controlling the opening of this duct and opening out in the undercap or underbody environment of the vehicle or in a vacuum area when the vehicle is in operation.

According to one embodiment, the air conditioning unit further comprises:

-a filter to filter the air coming from outside, this filter being regenerable by heating.

The invention also relates to a process for controlling the air conditioning of the air of a vehicle of the invention, characterized in that it comprises an operating mode corresponding to a significant heating demand of the passenger compartment in which:

- all the admitted air flow comes from outside and is directed in the additional circuit, or all the admitted air flow comes from the cockpit and is directed in the main circuit,

- the refrigerant circuit is deactivated if the air comes from outside or activated if the air comes from the passenger compartment,

- the main duct blower is deactivated if the air comes from outside or activated if the air comes from the passenger compartment,

- the additional blower is activated if the air comes from outside or deactivated if the air comes from the passenger compartment,

- all the air flow from the additional circuit passes through the air heater without being able to bypass it if the air comes from outside or from the main circuit

- the air flow is then transmitted to the passenger compartment.

According to one embodiment, the method comprises an additional operating mode corresponding to a so-called “economic” mode in which:

- all the admitted air flow comes from outside and is directed in the additional circuit, or in the main circuit,

- the refrigerant circuit is deactivated or activated depending respectively on the absence or presence of the need to dehumidify the admitted air,

- the main duct blower is deactivated if there is no need to dehumidify the intake air or activated if there is a need to dehumidify the intake air,

- the additional blower is activated if there is no need to dehumidify the intake air or deactivated if there is a need to dehumidify the intake air,

- all the air flow from the additional circuit in the absence of the need to dehumidify the intake air or the main circuit in the presence of the need to dehumidify the intake air bypasses the air heater,

- the air flow is then transmitted to the passenger compartment.

According to one embodiment, the method comprises an additional operating mode corresponding to a regulation of thermal comfort in which:

- part of the admitted air flow comes from the passenger compartment and directed into the main circuit

- the other part of the admitted air flow comes from outside and is directed into the main circuit or is directed into the additional circuit,

- the refrigerant circuit is deactivated,

- the main duct blower is activated,

- the additional blower is activated if air is directed into the additional circuit or deactivated if no air is directed into it,

- all the air flow from the additional circuit passes through the air heater if air is directed into the additional circuit or part of the air flow from the main circuit passes through the air heater if no air is directed into the circuit additional,

- the air flow having passed through the air heater is mixed, with that having only passed through the evaporator and is then transmitted to the passenger compartment.

According to one embodiment, the method comprises an operating mode corresponding to a request for significant cooling of the passenger compartment and a request for cooling of the heat engine, in which:

- part of the admitted air flow comes from the passenger compartment and is directed into the main circuit and the other part of the admitted air flow comes from the outside and is directed into the additional circuit, or all of the flow d intake air comes from outside and is directed into the main circuit and the additional circuit,

- the refrigerant circuit is activated,

- the main duct blower is activated,

- the additional blower is activated,

- all the air flow from the main circuit bypasses the air heater,

- all the air flow from the additional duct passes through the air heater and is discharged outside through the discharge duct.

According to one embodiment, the method comprises an operating mode corresponding to a request for cleaning the filter in which:

- all the admitted air flow comes from outside and is directed in the additional circuit,

- the refrigerant circuit is deactivated,

- the main duct blower is deactivated,

- the additional blower is activated,

- the filter is heated to a regeneration temperature after the deactivation of the blower and the activation of the additional blower,

- the air outlets to the passenger compartment are closed and all the air flow from the additional duct bypasses the air heater and the evaporator and is discharged outside via the discharge duct.

Other particularities and advantages will appear on reading the description below of a particular embodiment, without limitation of the invention, made with reference to the figures in which:

- Figure 1 is a schematic representation of a simple air conditioning unit according to the prior art.

- Figure 2 is a schematic representation of a dual zone air conditioning unit according to the prior art.

- Figure 3 is a schematic representation of the air flow in the air conditioning unit of Figure 1 during a significant heating demand.

- Figure 4 is a schematic representation of the air flow in the air conditioning unit of Figure 1 in the economic operation phase.

- Figure 5 is a schematic representation of the air flow in the air conditioning unit of Figure 1 in cabin comfort regulation mode.

- Figure 6 is a schematic representation of the air flow in the air conditioning unit of Figure 2 in cabin comfort regulation mode.

- Figure 7 is a schematic representation of an engine assembly of the invention.

- Figure 8 is a schematic representation of a first embodiment of the air conditioning unit of the invention.

- Figure 9 is a schematic representation of a variant of this first embodiment of the air conditioning unit of the invention.

- Figure 10 is a schematic representation of a second embodiment of the air conditioning unit of the invention.

- Figures 11a and 11b illustrate the air circulation in the air conditioning unit for a first mode of operation respectively for the first embodiment of the air conditioning group illustrated in Figure 8 and its variant in Figure 9.

- Figures 12a and 12b illustrate the circulation of air in the air conditioning unit for a second operating mode respectively for the first embodiment of the air conditioning unit illustrated in Figure 8 and its variant in Figure 9.

- Figures 13a and 13b illustrate the air circulation in the air conditioning unit for a third operating mode respectively for the first embodiment of the air conditioning group illustrated in Figure 8 and its variant in Figure 9.

FIGS. 14a and 14b illustrate the air circulation in the air conditioning unit for a fourth operating mode respectively for the first embodiment of the air conditioning group illustrated in FIG. 8 and its variant in FIG. 9.

FIGS. 15a and 15b illustrate the air circulation in the air conditioning group for a fifth operating mode respectively for the first embodiment of the air conditioning group illustrated in FIG. 8 and its variant in FIG. 9.

FIGS. 16a and 16b illustrate the air circulation in the air conditioning group for a sixth operating mode respectively for the first embodiment of the air conditioning group illustrated in FIG. 8 and its variant in FIG. 9.

FIGS. 17a and 17b illustrate the air circulation in the air conditioning group for a seventh operating mode respectively for the first embodiment of the air conditioning group illustrated in FIG. 8 and its variant in FIG. 9.

FIGS. 18a and 18b illustrate the air circulation in the air conditioning group for an eighth operating mode respectively for the first embodiment of the air conditioning group illustrated in FIG. 8 and its variant in FIG. 9.

FIGS. 19a and 19b illustrate the air circulation in the air conditioning group for a ninth operating mode respectively for the first embodiment of the air conditioning group illustrated in FIG. 8 and its variant in FIG. 9.

FIGS. 20a and 20b illustrate the air circulation in the air conditioning unit for a tenth mode of operation respectively for the first embodiment of the air conditioning group illustrated in FIG. 8 and its variant in FIG. 9.

FIG. 7 shows an engine assembly comprising a heat engine 20. The heat engine 20 may for example be an internal combustion engine with positive ignition or an internal combustion engine with compression ignition. Such an engine assembly preferably equips a vehicle, in particular a motor vehicle, to allow movement thereof.

The vehicle also includes an electronic computer, not shown. This calculator comprises the means of acquisition, of processing by software instructions stored in a memory as well as the control means required for implementing the control method described below.

The heat engine 20 is provided with a cooling circuit inside which a coolant circulates, such as a mixture of water and mono-ethylene glycol for example.

The cooling circuit includes an internal circuit 21 for circulating the coolant inside the heat engine. The cooling circuit is intended to take the calories generated by the heat engine and to evacuate them to maintain the heat engine at an acceptable operating temperature.

The inputs and outputs of the various members arranged in the cooling circuit are defined relative to the direction of circulation of the coolant.

The heat engine 20 is connected at the outlet of the internal circuit 21 to an inlet of a coolant outlet housing 22. The housing 22 is intended to distribute the coolant inside various branches of the cooling circuit.

The housing 22 includes a first coolant outlet fluidly connected, for example by means of a pipe, to an air heater 7 of the air conditioning group 12. The air heater 7 is crossed by an internal and / or external air flow which is intended to be supplied inside the passenger compartment H of the motor vehicle to heat an air present inside this passenger compartment H.

The housing 22 includes a second coolant outlet fluidly connected, for example by means of a pipe 23 to an inlet of a coolant pump 24. The coolant pump 24 includes an outlet connected to an inlet of the internal circuit 21 of the heat engine 20. The pipe 23 is a direct return pipe (conventionally designated by-pass in English) of coolant to the internal circuit 21 of the motor 20 via pump 24.

The housing 22 includes a third coolant outlet fluidly connected, for example by means of a pipe, to an inlet of a radiator 25. The radiator 25 is traversed by an external air flow to cool the coolant inside the radiator 25. The radiator is preferably housed with the engine 20 in the under-hood environment SC of the motor vehicle, separated from the passenger compartment H by a wall T called an apron, to facilitate heat exchange between the external air flow and the coolant inside the radiator 25. The housing 22 also includes a thermostat 26, which can be controlled and whose function is to distribute the coolant as a function of its temperature to the outlets of the housing 22. The radiator 25 comprises an outlet for coolant fluidly connected to an inlet of the housing 22.

The air conditioning unit interfaces with a heat exchange loop 27 inside which circulates a working fluid and to which the evaporator 4 and a condenser 28 are connected. The evaporator 4 is housed in the passenger compartment to facilitate the absorption of the calories present in the passenger air while the condenser 28 is housed in the environment under-cover SC to facilitate a heat exchange between the external air flow and the coolant inside of the radiator 25, and advantageously upstream of the latter taking into account the direction of circulation of the external air flow from the external environment at the front of the vehicle towards the environment of the engine under-hood of the vehicle. This heat exchange loop 27 also includes a compressor 29 usually arranged in the under-hood environment SC and driven by the heat engine 20, and a pressure reducer 30 for the working fluid.

The engine assembly may also include a motor-fan unit 31 to force the air flow passing through the radiator 25.

FIG. 8 now presents a first embodiment of an air conditioning unit according to the invention. Elements similar to the air conditioning unit in Figure 1 retain their reference.

This air conditioning group 12 includes a recirculation flap 1, depending on the equipment of the vehicle actuated manually by the occupants of the vehicle and / or automatically by the piloting and air quality regulation function in the passenger compartment. , which selects the composition of the air sucked in by the blower 2 through the first air intake A, between a source from the passenger compartment, H or from the outside E (in the latter case, via an air filter 3 arranged upstream of the recirculation flap 1, as explained above and with a view to the same advantages, disposed in the air duct conveying air from the outside E, either perpendicular to the axis of the duct, or at an angle so as to create an angle with the axis of this air duct).

The evaporator 4 of the refrigerant circuit is installed downstream and immediately at the outlet of the blower 2. At the immediate downstream side of the evaporator 4 is located in the local or global lower part a conduit 5 making it possible to evacuate outside the conveys condensate produced during refrigeration operation so that it does not fall inside the passenger compartment.

A second distribution flap 6 allows the air from the evaporator 4 to pass or not through the air heater 7 supplied with coolant from the heat engine.

The air conditioning arrives at outlet S of this main air conditioning circuit, then a final series of distribution flaps 9, 9 ', 9 ”allows the air from the mixing chamber 8 to be directed from the evaporator 4 and the air heater 7 to the different targeted zones in the passenger compartment: lower part of the passenger compartment, Hi, upper part of the passenger compartment, Hs, glazed areas to be defrosted / demisted, Hv, or good to shut up all the issues for him.

This air conditioning unit 12 also comprises an additional air circuit 13 comprising a second air intake A 'and an air outlet S' which opens into the main air conditioning circuit, between the evaporator 4 and the heater 7.

Arranged in this additional air circuit 13 downstream of the second air intake A ', an additional blower 2' sucks the air to be conditioned from the second air intake A 'and discharges it into the main air circuit through the exits'.

Thus this additional air circuit 13 bypasses the blower 2 and the evaporator 4 of the main air circuit.

The second air intake A 'of this duct advantageously opens upstream of the recirculation shutter 1, on the side of the exterior air intake E so as not to compete, in certain operating modes, with the refrigeration of the passenger compartment and do not increase the noise of the air intake by the two blowers 2 and 2 ', and downstream of the air filter 3 so as not to introduce dust or impurities coming from outside E. into the passenger compartment. , in this configuration, the second air intake A 'is arranged relative to the first air intake A so that the second air intake A' receives air entirely from outside E which whatever the position taken by the recirculation flap 1, this recirculation flap 1 being able to select for the first air intake A a composition of air aspirated entirely from the passenger compartment H or from the outside E or a méla air flow from cockpit H and outside E.

The opening of the outlet S ’of this additional air circuit 13 opening upstream of the air heater 7 is controlled by a dedicated flap 14.

It is also possible to provide, at the start of the main circuit immediately downstream of the air heater 7, an air delivery duct 15, the opening of which is also controlled by a dedicated flap 16. This conduit 15 is intended to open into the environment under the hood or advantageously under the vehicle body, in a vacuum zone in order to favor the dimensioning in flow rate and in pressure jump of the additional blower 2 ’.

The control of the air conditioning unit 12, more particularly the bypass of the evaporator 4, is based in particular on information relating to the degree of humidity present in the passenger compartment and more particularly to the levels of the front windows of the vehicle (windshield and side windows left and right).

The various components are controlled by the computer.

FIG. 9 shows a variant of the first embodiment of the air conditioning unit described in FIG. 8. In this variant, the second air intake A ′ is arranged relative to the first air intake A so that when the shutter 1 of recirculation selects for the first air intake A a composition of air aspirated entirely from the passenger compartment H, the second air intake A 'also receives air entirely coming from the passenger compartment H. The second air intake A 'in this case comprises an additional inlet flap 1' for controlling the opening of this second air intake A '.

FIG. 10 now shows a second embodiment of an air conditioning unit according to the invention. Elements similar to the air conditioning unit of Figure 8 and Figure 2 retain their reference. In this second embodiment, the air conditioning unit is said to be dual zone (“dual zone” in English).

Such an air conditioning unit makes it possible to differentiate according to the targeted zones the temperature of the air supplied to the passenger compartment H. As soon as the blower 2 exits, the air admitted into the main circuit of the air conditioning unit is dissociated into two circulating flows. in parallel in two conduits 10, 10 'and passing entirely through the evaporator 4. Two flaps 11, 11' arranged downstream of the evaporator 4 in each conduit 10, 10 'make it possible to bypass and / or pass through the air heater 7, in whole or in part.

We find, as for the air conditioning unit of Figure 8, the additional air circuit 13 which bypasses the blower 2 and the evaporator 4 of the main air circuit, the second air intake A 'of this through duct upstream of the recirculation flap 1 and downstream of the air filter 3 on the side of the outside air intake E. Arranged downstream of this second air intake A ′, an additional blower 2 ′ draws the air to condition the second intake A 'and discharge it into the main air circuit through the outlet S'. As for the air conditioning unit of Figure 8, the opening of the outlet S ’of this additional air circuit 13 opening upstream of the air heater 7 is controlled by a dedicated flap 14.

It is also possible to provide, at the start of the main circuit immediately downstream of the air heater 7, an air delivery duct 15, the opening of which is also controlled by a dedicated flap 16.

As for the variant of the first embodiment described in FIG. 9, one can provide, as a variant of this second embodiment of the air conditioning unit, a configuration in which the second air intake A 'is arranged relative to the first intake d 'air A so that when the recirculation shutter 1 selects for the first air intake A a composition of air entirely drawn from the passenger compartment H, the second air intake A' also receives 'air entirely from the passenger compartment H. The second air intake A' also includes in this case an additional inlet flap for controlling the opening of this second air intake A '.

Various operating modes of the air conditioning unit of the invention are presented below, presenting notable and energetically judicious alternatives compared to the state of the art known to those skilled in the art. The operating cases (ex: demisting / defrosting, significant refrigeration demand) the realization of which does not present a significant difference compared to the known state of the art will not be described although the air conditioning unit according to invention realizes the associated configurations among the set of allowed configurations.

A first mode of operation corresponds to a significant heating demand, without the need to dehumidify the admitted air. In this operating mode, the air conditioning unit adopts the configuration described by FIG. 11a and FIG. 11b respectively for the air conditioning group according to the embodiment described in FIG. 8 and in FIG. 9.

The determination of the need to dehumidify or not the admitted air can be obtained by the implementation of a humidity sensor or a strategy capable of precisely anticipating the appearance of fogging on the glazing.

In this operating mode:

- The recirculation flap 1 and, where appropriate, the additional flap 1 ’occupy a position such that all of the admitted air flow comes from outside E and is directed into the additional circuit 13,

- The refrigerant circuit is deactivated,

- The main duct blower 2 is deactivated,

- The additional 2 ’blower is activated,

- The shutter 14 is open to ensure the outlet of the additional circuit 13 for bypassing the evaporator 4 in the mixing chamber 8 of the air conditioning unit, upstream of the air heater 7,

- The distribution flap 6 occupies a position such that all the air flow from the additional circuit 13 passes through the air heater 7 without being able to bypass it and is then thus transmitted to the passenger compartment H.

Where appropriate, the discharge duct 15, disposed downstream of the air heater 7 and opening into the environment under the hood or under the body, is obscured by the dedicated flap 16.

The air flow is then fully transmitted to the passenger compartment H.

Consequently, in this mode of operation, the method of the invention makes it possible to bypass the evaporator 4 and thus to get rid of its unnecessary aerodynamic resistance opposing the flow of air, and the increased power consumption of the blower to compensate for it.

A second operating mode corresponds to a significant heating demand, with the need to dehumidify the admitted air. In this operating mode, the air conditioning group adopts the configuration described by FIG. 12a and FIG. 12b respectively for the air conditioning group according to the embodiment described in FIG. 8 and in FIG. 9.

In this operating mode:

- The recirculation flap 1 and, where appropriate, the additional flap 1 ’occupy a position such that all the admitted air flow comes from the passenger compartment and is directed into the main circuit,

- The refrigerant circuit is activated,

- The main duct blower 2 is activated

- The additional 2 ’blower is deactivated,

- The shutter 14 is closed.

- The distribution flap 6 occupies a position such that all of the air flow from the evaporator 4 passes through the air heater 7 without being able to bypass it.

Where appropriate, the delivery duct 15 is obscured by the dedicated flap 16. The air flow is then fully transmitted to the passenger compartment H.

Thus, in this second mode of operation, the crossing of the evaporator 4 with active refrigeration is restored at the expense of its aerodynamic resistance necessarily compensated by the increase in the electrical consumption of the blower.

A third mode of operation corresponds to economical operation of the air conditioning, without the need to dehumidify the admitted air. In this operating mode, the air conditioning unit adopts the configuration described by FIG. 13a and FIG. 13b respectively for the air conditioning group according to the embodiment described in FIG. 8 and in FIG. 9.

In this operating mode, the operator selects for example an “all cold” setting but without refrigeration being activated.

In this operating mode:

- The recirculation flap 1 and, where appropriate, the additional flap 1 ′ preferably occupy a position such that all of the admitted air flow comes from outside E and is directed into the additional circuit 13,

- The refrigerant circuit is deactivated,

- The main duct blower 2 is deactivated,

- The additional 2 ’blower is activated,

- The flap 14 is open,

- The distribution flap 6 occupies a position such that all of the air flow from the additional circuit bypasses the air heater 7 without passing through it,

- If necessary, the delivery duct 15 is obscured by the dedicated flap 16.

The air flow is then transmitted to the passenger compartment H.

Thus, the entire filtered air flow admitted at the outside ambient temperature bypasses the evaporator 4 and the air heater 7 before entering the passenger compartment H. This operating mode is energetically relevant (non-drive of the compressor 29 and the if necessary from the fan-motor unit 31) when refrigeration is not required to provide the expected cooling of the passenger air and the outside temperature is sufficient to cool the passenger compartment. In the case of an air conditioning unit conforming to the state of the art illustrated in FIG. 1, its internal architecture would require the flow of air sent into the passenger compartment to first pass through the evaporator, however inactive since in this mode cabin refrigeration is deactivated.

Consequently, in this third mode of operation, the air conditioning unit makes it possible in particular to bypass the evaporator 4, the refrigerant circuit then being inactive, but also the air heater 7, and thus to get rid of their air resistance and the power consumption of pulser 2 in order to compensate for them. This so-called economical operating mode is, in the case of an air conditioning unit in accordance with the invention, all the more so since the outside air is transmitted to the passenger compartment H without passing through any heat exchanger (evaporator 4, air heater 7).

A fourth operating mode corresponds to an economical operation of the air conditioning, with the need to dehumidify the admitted air. In this operating mode, the air conditioning group adopts the configuration described by FIG. 14a and FIG. 14b respectively for the air conditioning group according to the embodiment described in FIG. 8 and in FIG. 9.

In this operating mode:

- The recirculation flap 1 and, where appropriate, the additional flap 1 ’occupy a position such that all of the admitted air flow comes from outside E and is directed into the main circuit,

- The refrigerant circuit is activated,

- The main duct blower 2 is activated

- The additional 2 ’blower is deactivated,

- The shutter 14 is closed,

- The distribution flap 6 occupies a position such that all of the air flow from the main circuit bypasses the air heater 7 without passing through it,

- If necessary, the delivery duct 15 is obscured by the dedicated flap 16.

The air is then fully transmitted to the passenger compartment H.

A fifth operating mode corresponds to an operation in thermal regulation of the passenger compartment air, by mixing cold air cooled at the crossing of the evaporator 4 and hot air heated at the crossing of the air heater 7, without the need to dehumidify the intake air. In this operating mode, the air conditioning unit adopts the configuration described by FIG. 15a and FIG. 15b respectively for the air conditioning group according to the embodiment described in FIG. 8 and in FIG. 9.

In this operating mode:

- The recirculation flap 1 and, where appropriate, the additional flap 1 'occupy a position such that all or part of the air flow directed into the main circuit comes from the passenger compartment H while the air admitted passing through the additional circuit 13 comes entirely from outside E,

- The refrigerant circuit is deactivated,

- Pulser 2 of the main duct is activated,

- The additional 2 ’blower is activated,

- The flap 14 is open,

- The distribution flap 6 occupies a position such that all of the air flow from the additional circuit passes through the air heater 7 and such that all of the air flow from the evaporator 4 bypasses the air heater 7,

- If necessary, the discharge conduit 15 is obscured by the dedicated flap 16.

The flow of air heated at the crossing of the air heater is then mixed, downstream of the air heater 7, with the air flow having in parallel passed through the evaporator 4 and is then transmitted to the passenger compartment H.

In this fifth operating mode, in the event of little or no need to dehumidify the admitted air, it is then not necessary to dehumidify all of the air admitted into the air conditioning unit, which then dissociates the flow of air passing through the evaporator 4 from that passing through the air heater 7. Thus, the air flow arriving at the inlet of the air heater 7 to be heated therein is not previously cooled by passing through the evaporator 4. the air available at the outlet of the air heater 7 is then warmer to regulate the air finally admitted into the passenger compartment H to the desired temperature, by reducing or canceling the energy expenditure of additional heating elements and without slowing down the temperature rise of the heat engine 20 by avoiding excessively cooling through the air heater 7 the air coolant from the evaporator 4 to a temperature below the ambient temperature outdoor te.

The fifth operating mode thus constitutes an energy-wise alternative to the state of the art, when the operating conditions (in particular: little or no need for dehumidification) allow its adoption by the air conditioning group according to the invention.

A sixth operating mode corresponds to an operation with thermal regulation of the passenger compartment air, with the need to dehumidify the admitted air. In this operating mode, the air conditioning group adopts the configuration described by FIG. 16a and FIG. 16b respectively for the air conditioning group according to the embodiment described in FIG. 8 and in FIG. 9.

In this operating mode:

- The recirculation flap 1 and, where appropriate, the additional flap 1 ′ occupy a position such that part of the admitted air flow comes from the passenger compartment H and is directed into the main circuit, another part of the flow of intake air comes from outside E and is also directed into the main circuit,

- The refrigerant circuit is activated,

- Pulser 2 of the main duct is activated,

- The additional 2 ’blower is deactivated,

- The shutter 14 is closed,

- The distribution flap 6 occupies a position such that part of the air flow from the main circuit at the outlet of the evaporator 4 passes through the air heater 7,

- If necessary, the discharge conduit 15 is obscured by the dedicated flap 16.

A seventh mode of operation corresponds to a significant demand for refrigeration, without the need to dehumidify the admitted air. In this operating mode, the air conditioning group adopts the configuration described by FIG. 17a and FIG. 17b respectively for the air conditioning group according to the embodiment described in FIG. 8 and in FIG. 9.

In this operating mode:

- The recirculation flap 1 and, where appropriate, the additional flap 1 ’occupy a position such that all of the admitted air flow comes from the passenger compartment H and is directed into the main circuit,

- The refrigerant circuit is activated,

- Pulser 2 of the main duct is activated,

- The additional 2 ’blower is deactivated,

- The shutter 14 is closed,

- The distribution flap 6 occupies a position such that all the air flow from the main circuit at the outlet of the evaporator 4 bypasses the air heater 7,

- If necessary, the delivery duct 15 is obscured by the dedicated flap 16.

The air is then fully transmitted to the passenger compartment H.

An eighth mode of operation corresponds to a significant demand for refrigeration of the air supplied to the passenger compartment and at the same time a significant need for cooling of the thermal engine. In this operating mode, the air conditioning group adopts the configuration described by FIG. 18a and FIG. 18b respectively for the air conditioning group according to the embodiment described in FIG. 8 and in FIG. 9.

In this operating mode:

- The recirculation flap 1 and, where appropriate, the additional flap 1 ′ occupy a position such that the flow of air admitted from the passenger compartment H is directed into the main circuit, while the flow of air admitted from l the exterior is directed into the additional circuit 13,

- The refrigerant circuit is activated,

- Pulser 2 of the main duct is activated,

- The additional 2 ’blower is activated,

- The flap 14 is open,

- The distribution flap 6 occupies a position such that all the air flow from the main circuit at the outlet of the evaporator 4 bypasses the air heater 7 and such that all the air flow from the additional circuit 13 passes through the air heater 7,

- The discharge duct 15 is not obscured by the dedicated flap 16 and all the air flow from the additional duct 13 and having passed through the air heater 7 is evacuated outside.

In this operating mode, the air heater 7 is usefully dedicated to cooling the heat engine. Thus, the air conditioning unit, while ensuring the substantial refrigeration then required for the passenger compartment, irrigates the air heater 7 in parallel by an air flow coming from the outside, this air flow then being, downstream of the air heater, discharged outside, into the environment under the body or under the hood, without being mixed downstream of the air heater 7 with the air flow having in parallel passed through the evaporator 4 to be cooled there before its introduction in the passenger compartment H via the flaps 9, 9 ', 9 ”, and without degrading the acoustic, olfactory and thermal comfort then provided in the passenger compartment. This provides the heat transfer circuit of the engine with additional cooling power, without implementing an additional heat exchanger, through the flow of the air heater by an air flow. The configuration then taken in this eighth mode of operation by the air conditioning unit according to the invention achieves two separate air circuits which do not mix.

A ninth operating mode corresponds to a significant demand for refrigeration of the air supplied to the passenger compartment and at the same time a significant need for cooling of the heat engine, in the case where the air passing through the air conditioning unit and the ducts main and additional air 13 is sucked in from outside the filter 3. In this operating mode the air conditioning group adopts the configuration described in FIG. 19a and in FIG. 19b respectively for the air conditioning group according to the embodiment described in Figure 8 and Figure 9.

In this operating mode:

- the recirculation flap 1 and, where appropriate, the additional flap 1 ′ occupy a position such that all of the admitted air flow comes from outside E and is directed into the main circuit and the additional circuit 13,

- the refrigerant circuit is activated,

- the main duct blower 2 is activated,

- the additional 2 ’blower is activated,

- the flap 14 is open,

the distribution flap 6 occupies a position such that all of the air flow from the main circuit bypasses the air heater 7 and such that all of the air flow from the additional circuit 13 passes through the air heater 7,

- the discharge duct 15 is not obscured by the dedicated flap 16 and all the air flow coming from the additional duct 13 and having passed through the air heater 7 is evacuated outside.

A tenth operating mode corresponds to a request to clean the filter 3. In this operating mode the air conditioning unit adopts the configuration described in FIG. 18a and in FIG. 18b respectively for the air conditioning group according to the embodiment described in Figure 8 and Figure 9.

For this operating mode, a regenerable filter 3 is provided. This filter 3 may for example be of the activated carbon type, capable of capturing the pollutants, dust, microorganisms, etc. transported by the air flow from the outside, which must be trapped so that they do not not fit into the passenger compartment. A filter of this type is generally equipped with an electrical resistance or is itself an electrical conductor, and the activation of which heats by Joule effect the filter to a regeneration temperature sufficient to cause the desorption of the filter of pollutants and of the majority trapped impurities. When cleaning this filter, the air outlets to the passenger compartment must be blocked so that these pollutants, impurities, micro-organisms, etc. can never enter the passenger compartment. According to the invention, use is made of the exhaust duct 15 disposed downstream of the air heater 7 and opening out to the outside of the vehicle in an environment under the hood or under the body. Thus, the air loaded with dust and other pollutants is discharged outside the vehicle.

Thus, in this operating mode:

- the recirculation flap 1 and, where appropriate, the additional flap 1 ’occupy a position such that all of the admitted air flow comes from outside E and is directed into the additional circuit 13,

- the refrigerant circuit is deactivated,

- the main duct blower 2 is deactivated,

- the additional blower 2 ’is activated and thus draws in air through the filter 3 from outside E,

- the filter 3 is heated, to desorb pollutants, impurities, micro-organisms, etc. The existence of an air flow passing through the filter 3 during the initiation of its desorption makes it possible to entrain the particles as soon as they are released, without the risk of them being deposited. Thus, the electrical activation of the filter 3 (or if necessary of its heating resistance) is therefore preferably subsequent to the deactivation of the blower 2 and to the activation of the additional blower 2 ’.

- the flap 14 is open,

the distribution flap 6 occupies a position such that all of the air flow coming from the additional circuit 13 bypasses the air heater 7,

- the discharge duct 15 is not obscured by the dedicated flap 16 which evacuates outside the vehicle by the discharge duct 15 the air flow arriving at the outlet S of the main circuit of the air conditioning unit, upstream of the distribution flaps 9, 9 'and 9 ”.

- the air outlets to cockpit H are all closed,

- all of the air flow from the additional circuit 13 is evacuated via the discharge pipe 15, without having passed through any heat exchanger (neither the evaporator 4 nor the air heater 7).

The operating modes described for the air conditioning group embodiments described in FIG. 8 and in FIG. 9 and are applicable to the air conditioning group embodiment described in FIG. 10 and its variant (not shown).

The invention makes it possible to eliminate the air resistance of the evaporator 4, when its operation is not necessary and, by this means, to reduce the electrical consumption of the blower 2.

The invention also makes it possible to eliminate, when dehumidification of the admitted air is not necessary, its pre-cooling before its reheating, imposed according to the state of the art by passing through the operating evaporator 4 and, through this, to reduce the energy consumption of additional heating elements and the fuel consumption of the heat engine 20 by accelerating its rise in temperature.

The invention also makes it possible to improve the cooling of the heat engine 20 by the now possible operation of the air heater 7 (according to the state of the art inactive since bypassed) via its passage through a flow of air then rejected by under body or under hood.

Claims (10)

claims 1. Vehicle equipped with an internal combustion engine and its liquid cooling circuit, an air conditioning unit (12) comprising: - a main air circuit comprising from upstream to downstream: - a first intake (A) of air to be conditioned, - an air blower (2), - an evaporator (4) of a refrigerant circuit, - an air heater (7) connected to the cooling circuit of the heat engine, - a distribution flap (6) which allows the air coming from the evaporator (4) to pass or not through the air heater (7), - an air conditioning outlet (S) to a passenger compartment (H) of the vehicle, - shutter means (9, 9 ’, 9”) of the air conditioning outlet (S) to the passenger compartment (H), - a recirculation flap (1) which selects the composition of the air drawn in by the first air intake (A), from a source from the passenger compartment (H) or from the outside (E) or from a mixture of air from the passenger compartment (H) and from the outside (E), characterized in that it comprises an additional air circuit (13) comprising: - a second intake (Aj of air to be conditioned, - an additional blower (2 days, - an air outlet (S j which opens into the main circuit between the air heater (7) and the evaporator (4), downstream of the distribution flap (6), - a flap (14) for controlling the air outlet (Sj, and in that the distribution flap (6) also allows the air coming from the additional air circuit (13) to pass or not through the '' air heater (7). 2. Vehicle according to claim 1, characterized in that the second air intake (Aj is arranged relative to the first air intake (A) so that when the recirculation flap (1) selects for the first intake d 'air (A) a composition of air aspirated entirely from the passenger compartment (H), the second air intake (Aj also receives air entirely from outside (E). 3. Vehicle according to claim 1, characterized in that the second air intake (Aj is arranged relative to the first air intake (A) so that: - when the recirculation flap (1) selects for the first air intake (A) a composition of air aspirated entirely from the passenger compartment (H), the second air intake (Aj also receives from all the air coming from the passenger compartment (H), - when the recirculation flap (1) selects for the first air intake (A) a composition of air aspirated entirely from the outside (E), the second air intake (Aj also receives air entirely from the outside (E), and in that the second air intake (Aj comprises a flap (1d additional inlet, placed relative to the direction of entry of air into the group ( 12) air conditioning, downstream of the recirculation flap (1). 4. Vehicle according to any one of the preceding claims, characterized in that the air conditioning unit (12) comprises an air delivery duct (15) at the start of the main air circuit, between the air conditioning outlet (S) and the air heater (7) and a flap (16) for controlling the opening of this duct (15) and opening into the under-hood or under-body environment of the vehicle or into a vacuum zone when the vehicle is in operation. 5. Vehicle according to claim 4, characterized in that the air conditioning unit (12) further comprises: -a filter (3) for filtering the air coming from outside, this filter (3) being regenerable by heating. 6. Method for controlling the air conditioning of a vehicle according to any one of the preceding claims, characterized in that it comprises an operating mode corresponding to a significant heating demand for the passenger compartment in which: - all the admitted air flow comes from outside (E) and is directed in the additional circuit (13), or all the admitted air flow comes from the passenger compartment (H) and is directed in the main circuit , - the refrigerant circuit is deactivated if the air comes from outside or activated if the air comes from the passenger compartment, - the blower (2) of the main duct is deactivated if the air comes from outside or activated if the air comes from the passenger compartment, - the blower (2 additional days is activated if the air comes from outside or deactivated if the air comes from the passenger compartment, - all the air flow from the additional circuit (13) passes through the air heater (7) without being able to bypass it if the air comes from outside or from the main circuit - the air flow is then transmitted to the passenger compartment (H). 7. Method according to claim 6, characterized in that it comprises an additional operating mode corresponding to a so-called "economic" mode in which: - all the admitted air flow comes from outside (E) and is directed in the additional circuit (13), or in the main circuit, - the refrigerant circuit is deactivated or activated depending respectively on the absence or presence of the need to dehumidify the admitted air, - the blower (2) of the main duct is deactivated if there is no need to dehumidify the intake air or activated if there is a need to dehumidify the intake air, - the blower (additional 2d is activated if there is no need to dehumidify the intake air or deactivated if there is a need to dehumidify the intake air, - all the air flow from the additional circuit (13) in the absence of the need to dehumidify the intake air or the main circuit in the presence of the need to dehumidify the intake air bypasses the air heater (7) , - the air flow is then transmitted to the passenger compartment (H). 8. Method according to claim 6 or claim 7, characterized in that it comprises an additional operating mode corresponding to a regulation of the thermal comfort in which: - part of the admitted air flow comes from the passenger compartment (H) and directed into the main circuit - the other part of the admitted air flow comes from outside (E) and is directed into the main circuit or is directed into the additional circuit (13), - the refrigerant circuit is deactivated, - the blower (2) of the main duct is activated, - the blower (2d additional is activated if air is directed into the additional circuit (13) or deactivated if no air is directed there, - all the air flow from the additional circuit passes through the air heater (7) if air is directed into the additional circuit (13) or part of the air flow from the main circuit passes through the air heater (7 ) if no air is directed into the additional circuit, - the air flow having passed through the air heater (7) is mixed, with that having only passed through the evaporator (4) and is then transmitted to the passenger compartment (H). 9. A method of controlling the air conditioning of a vehicle according to claim 4, characterized in that it comprises an operating mode corresponding to a significant cooling demand of the passenger compartment and a cooling cooling demand of the engine, in which : - part of the admitted air flow comes from the passenger compartment (H) and is directed into the main circuit and the other part of the admitted air flow comes from outside (E) and is directed into the additional circuit (13), or the entire admitted air flow comes from outside (E) and is directed into the main circuit and the additional circuit (13), - the refrigerant circuit is activated, - the blower (2) of the main duct is activated, - the blower (additional 2 days is activated, - all the air flow from the main circuit bypasses the air heater (7), - all of the air flow from the additional duct (13) passes through the air heater (7) and is discharged outside by the discharge duct (15). 10. A method for controlling the air conditioning of a vehicle according to claim 5, characterized in that it comprises an operating mode corresponding to a request for cleaning the filter in which: - all of the admitted air flow comes from outside (E) and is directed into the additional circuit (13), - the refrigerant circuit is deactivated, - the main duct blower (2) is deactivated, - the blower (2d additional is activated, - the filter (3) is heated to a regeneration temperature after deactivation of the blower (2) and activation of the blower (2 additional days, - the air outlets to the passenger compartment are closed and all the air flow from the additional duct (13) bypasses the air heater (7) and the evaporator (4) and is discharged outside through the duct (15) discharge.