Automotive air treatment system equipped with a HEPA filter

Abstract

The invention relates to an air treatment system (1) for a motor vehicle comprising an outside air intake duct (2), a passenger compartment air recirculation duct (3), a diffuser duct (4) housing a motor-fan assembly (5) and a first air filter (6), a two-way flow filtration duct (7) housing a second HEPA-type air filter (8), and two bypass ducts (9, 10), said system further comprising a first airflow control flap (11) arranged at the interface between the outlet of said intake duct, a first inlet / outlet of said filtration duct, and the inlet of said first bypass duct; and a second airflow control flap (12) arranged at the interface between the outlet of said recirculation duct, the second inlet / outlet of said filtration duct, and the inlet of said second bypass duct. Figure to be published with the abbreviation: Fig. 1

Description

Title of the invention: Air treatment system for motor vehicles equipped with a HEPA filter technical field

[0001] The present invention relates generally to air treatment systems within the passenger compartment of motor vehicles.

[0002] The invention relates in particular to such an air treatment system for a motor vehicle equipped with a HEPA type air filter. Previous technique

[0003] In a known manner, a motor vehicle includes an air treatment system within the passenger compartment of that vehicle in order to ensure the comfort of the passengers.

[0004] Generally referred to by the acronym HVAC (for Heating, Ventilation and Air-Conditioning), such an air treatment system typically includes: - an outside air intake duct whose inlet is fluidly connected to the outside of the vehicle; - a passenger compartment air recirculation duct whose inlet is fluidically connected to the interior of the vehicle's passenger compartment; and - a diffusion duct whose outlet is fluidically connected to the interior of the vehicle's passenger compartment.

[0005] The HVAC air handling system also includes a motor-fan unit and at least one first air filter housed in the diffusion duct, these two elements generally being integrated into an HVAC module located under the dashboard of the vehicle.

[0006] Such an HVAC air handling system further includes an airflow control flap arranged at the interface between the outlet of the outside air intake duct, the outlet of the recirculation duct and the inlet of the diffusion duct.

[0007] This control flap is movable between an open position in which said outside air intake and diffusion ducts are fluidly connected so that the blown air entering the passenger compartment comes only from outside the vehicle, and a closed position in which said recirculation and diffusion ducts are fluidly connected so that the blown air entering the passenger compartment is only recycled air.

[0008] The actuation of this airflow control flap can generally be controlled either manually by the driver or the front passenger via control devices mechanical or touch controls, or automatically via the HVAC air handling system supervision module.

[0009] In order to improve the quality of the passenger compartment air, it is also known, in particular from US 10525395 B2, to have a HEPA type air filter (for "High Efficiency Particles Arresting" in English, which translates into French as [filter] with high efficiency against airborne particles) in the outside air intake duct.

[0010] Such a HEPA filter is capable of filtering at least 99.95% of fine particles, invisible to the naked eye, with a diameter greater than or equal to 0.3 micrometers (pm).

[0011] In order to compensate for the pressure losses generated by these HEPA filters, the latter must have relatively large surface dimensions which can reach or even exceed 30 dm2, so that they must be installed in the engine compartment of the vehicle outside the HVAC module due to insufficient free space under the dashboard.

[0012] These significant pressure losses also result in a substantial increase in the electrical power absorbed by the motor-fan unit for a given air flow rate at the filter outlet.

[0013] This electrical power proves to be particularly important during rapid cooling phases initiated for example at the start-up of vehicles with a very high passenger temperature resulting from prolonged exposure in full sun during the summer.

[0014] During such a rapid cooling phase, the pressure losses caused by the HEPA filter (which vary according to the square of the air flow into the filter) are indeed particularly significant since the motor-fan unit then operates at its maximum electrical power so that the air flow entering the passenger compartment is as high as possible (approximately 500 kg / h) in order to ensure rapid cooling of this passenger compartment.

[0015] It is therefore understood that the installation of such a HEPA filter requires an oversizing of the motor-fan unit whose maximum operating power must be greater than that of a conventional motor-fan unit equipping vehicles without this type of filter.

[0016] Besides the additional cost and increased operating noise caused by this oversizing of the motor-fan unit, the major drawback of installing such a HEPA filter lies in the increased electrical consumption generated, this criterion being particularly sensitive in the case of electric vehicles for which the loss of autonomy can prove to be relatively significant.

[0017] A known HVAC module comprising: is also known from US patent 2020 / 0376934 A1 - a housing defining an air inlet and an air outlet connected by an air duct, this air inlet being able to be fluidically selectively connected to an outside air intake duct and to a passenger compartment air recirculation duct; - a first air filter positioned inside the air duct; - a second HEPA-type air filter positioned downstream of the first air filter inside the air duct; and - an airflow control flap positioned in the housing and which can be selectively operated to connect the air passage to a bypass duct further defined by the housing.

[0018] The bypass duct has an inlet located at the flap and opening into the air duct downstream of the first air filter and upstream of the second HEPA air filter. This bypass duct also has an outlet opening into the bypass duct downstream of the second HEPA air filter.

[0019] Thus, depending on the position of the pilot flap, the airflow passes either only through the first air filter, or successively through this first air filter and the second HEPA filter.

[0020] Such an implantation of the second HEPA filter downstream of the first air filter in the HVAC module unfortunately forces a drastic limitation of its dimensions and therefore its efficiency. Description of the invention

[0021] The present invention therefore aims to improve the situation.

[0022] For this purpose, it proposes an air treatment system for motor vehicles comprising an outside air intake duct, a passenger air recirculation duct, a diffusion duct opening into the passenger compartment of said vehicle and housing a motor-fan unit and a first air filter; characterized in that it also includes: - a two-way flow filtration duct housing a second HEPA-type air filter and extending between the outlet of said intake duct and the outlet of said recirculation duct, - a first bypass duct extending between the outlet of said intake duct and the inlet of the diffusion duct, and - a second bypass duct extending between the outlet of said recirculation duct and the inlet of said diffusion duct, said system further comprising: - a first airflow control flap arranged at the interface between the outlet of said intake duct, a first inlet / outlet of said filtration duct, and the inlet of said first bypass duct; and - a second airflow control flap, arranged at the interface between the outlet of said recirculation duct, the second inlet / outlet of said filtration duct and the inlet of said second bypass duct.

[0023] The air treatment system according to the invention thus makes it possible to control the path of the air flow (outside or recycled) according to different configurations so that it can selectively pass either only through the first air filter bypassing the second HEPA air filter, or pass successively through this second HEPA air filter and this first air filter.

[0024] Moreover, such an air treatment system according to the invention is perfectly compatible with an implantation of the second HEPA air filter in the engine compartment of the vehicle, so that its dimensions and therefore its efficiency are optimal.

[0025] According to a preferred feature of said air handling system according to the invention, said first pilot flap is movable between: - a first position in which said inlet duct, said first bypass duct and said filtration duct are fluidically connected; - a second position in which only the said inlet and filtration ducts are fluidically connected while the inlet of said first bypass duct is sealed; and - a third position in which only the said filtration duct and the said first bypass duct are fluidically connected while the outlet of the said intake duct is closed; said second control component being mobile between: - a first position in which only said filtration duct and said second bypass duct are fluidically connected, while the outlet of said recirculation duct is sealed; and - a second position in which only the said recirculation and filtration ducts are fluidically connected, while the inlet of said second bypass duct is closed.

[0026] The air treatment system according to the invention is advantageously suited to operate in a first mode in which: - said first control flap occupies its first position so that the pulsed air, entering the passenger compartment and coming solely from outside the vehicle, circulates successively in said intake duct, said first bypass duct and said diffusion duct, passing only through said first air filter, and - said motor-fan unit is operating at its maximum electrical power.

[0027] This first mode of operation is, for example, configured to activate automatically when there is at least one passenger in the vehicle and when the temperature inside the passenger compartment is above a predetermined threshold temperature.

[0028] The air treatment system according to the invention is also advantageously capable of operating in a second mode in which: - said first pilot flap occupies its second position and where said second pilot flap occupies its first position, so that the pulsed air, entering the passenger compartment and coming solely from outside the vehicle, circulates successively in said intake duct, said filtration duct, said second bypass duct and said diffusion duct, passing successively through said second HEPA air filter and said first air filter; and - said motor-fan unit is operating at its maximum electrical power.

[0029] This second operating mode is configured, for example, to activate automatically when there are no passengers in the vehicle and when the temperature inside the passenger compartment is above a predetermined threshold temperature.

[0030] According to one feature, the face of this second HEPA air filter which is first crossed by the airflow in said second operating mode is covered with an antistatic pre-filter.

[0031] The air treatment system according to the invention is further advantageously able to operate in a third mode in which said first pilot flap occupies its third position and said second pilot flap occupies its second position, so that the pulsed air, entering the passenger compartment and consisting solely of recycled air, circulates successively in said recirculation duct, said filtration duct, said first bypass duct and said diffusion duct, passing successively through said second HEPA air filter and said first air filter.

[0032] This third operating mode is, for example, configured to activate automatically when there is at least one passenger in the vehicle and when the temperature inside the passenger compartment is less than or equal to a predetermined threshold temperature.

[0033] The invention also relates, in a second aspect, to a motor vehicle comprising such an air treatment system. Brief description of the drawings

[0034] The description of the invention will now be continued by a detailed description of several embodiments, given below by way of illustration but not limitation, with reference to the accompanying drawings, on which: - [Fig.1] represents a schematic view of an HVAC air handling system according to the invention for a motor vehicle; - [Fig.2] is a view of the HVAC air handling system according to the invention in a configuration corresponding to its first mode of operation; - [Fig.3] represents a view of the HVAC air handling system according to the invention in a configuration corresponding to its second mode of operation; and - [Fig.4] is a view of the HVAC air handling system according to the invention in a configuration corresponding to its third mode of operation. Description of the implementation methods

[0035] With reference to [Fig. 1], the HVAC air handling system 1 according to the invention comprises: - an outside air intake duct 2 whose inlet is fluidically connected to the outside E of the vehicle; - a passenger compartment air recirculation duct 3 whose inlet is fluidically connected to the interior of the passenger compartment H of the vehicle; - a diffusion duct 4 whose outlet is fluidically connected to the interior of the vehicle's passenger compartment H, this diffusion duct 4 housing a motor-fan unit 5 and a first air filter 6; - a two-way flow filtration duct 7 extending between the outlet of the intake duct 2 and the outlet of the recirculation duct 3, this filtration duct 7 housing a second HEPA type air filter 8; - a first bypass duct 9 extending between the outlet of the intake duct 2 and the inlet of the diffusion duct 4; and - a second bypass duct 10 extending between the outlet of the recirculation duct 3 and the inlet of the diffusion duct 4.

[0036] In the remainder of this description, the terms "upstream" and "downstream" used to characterize the position of certain elements of the air treatment system 1 will be considered in relation to the direction of airflow in the ducts 2, 3, 4, 9 and 10.

[0037] The first air filter 6 is advantageously made up of a high efficiency (HE) filter making it possible to filter gaseous pollutants such as volatile organic compounds (VOCs), dust and fine particles such as those with an average diameter of 2.5 pm (PM 2.5) and those with an average diameter of 9 pm (PM 9).

[0038] This first air filter 6 can also consist of a simple pollen filter, an activated carbon filter for neutralizing odors, or a biocide filter providing more effective allergen filtration. This filter 6 can also to be made up of a plurality of layers, each layer performing the function of one of the filters defined previously.

[0039] The second HEPA 8 type air filter is advantageously of class H13 so as to ensure the filtration of at least 99.95% of fine particles, invisible to the naked eye, with a diameter greater than or equal to 0.3 micrometers (pm).

[0040] According to alternative embodiments, this second HEPA 8 filter can be of an even more efficient class (for example, class H14 ensuring the filtering of at least 99.995% of fine particles, invisible to the naked eye, with a diameter greater than or equal to 0.3 micrometers).

[0041] This second HEPA filter 8 is also advantageously located in the vehicle's engine compartment under the front hood, so that the passenger air recirculation ducts 3 and the bypass ducts 9, 10 pass through the vehicle's bulkhead separating the engine compartment and the passenger compartment, this bulkhead being schematically represented on this [Fig.1] by the dashed line T.

[0042] The HVAC air handling system 1 also includes a first airflow control flap 11, arranged at the interface between the outlet of the intake duct 2, a first inlet / outlet of the filtration duct 7 and the inlet of the first bypass duct 9.

[0043] This first control flap 11 is movable via a motorized actuator not shown between: - a first position (see [Fig.2]) in which the inlet duct 2, the first bypass duct 9 and the filtration duct 7 are fluidly connected; - a second position (see [Fig.3]) in which only the inlet duct 2 and the filter duct 7 are fluidically connected, while the inlet of the first bypass duct 9 is blocked; and - a third position (see [Fig.4]) in which only the filtration conduit 7 and the first bypass conduit 9 are fluidically connected, while the outlet of the inlet conduit 2 is closed.

[0044] The HVAC air handling system 1 further includes a second airflow control flap 12, arranged at the interface between the outlet of the recirculation duct 3, the second inlet / outlet of the filtration duct 7 and the inlet of the second bypass duct 10.

[0045] This second control flap 12 is movable via a motorized actuator not shown between: - a first position (see figures 2 and 3) in which only the filtration duct 7 and the second bypass duct 10 are fluidically connected, while the outlet of the recirculation duct 3 is blocked; and - a second position (see [Fig.4]) in which only the recirculation duct 3 and filtration duct 7 are fluidically connected, while the inlet of the second bypass duct 10 is closed.

[0046] The HVAC air treatment system 1 also includes a supervisory module not shown capable of managing, autonomously or according to command orders transmitted by the vehicle's passengers, the operation of the motor-fan unit 5 in order to adapt the flow of forced air exiting the latter as well as the operation of the first and second air flow control flaps 11, 12.

[0047] Preferably consisting of the vehicle's BSI (for "Intelligent Servicing Box") also called VSM (for "Vehicle Supervisor Module" in English) in common terminology, this supervision module includes a computer with one or more interconnected microprocessors, as well as a memory module comprising non-volatile and non-volatile memory.

[0048] This monitoring module is capable of operating the vehicle's HVAC air handling system 1 in a first mode known as "rapid cooling" illustrated by [Fig. 2] and in which: - the first airflow control flap 11 occupies its first position so that the pulsed air, entering the passenger compartment H and coming only from outside E of the vehicle, circulates successively in the outside air intake duct 2, the first bypass duct 9 and the diffusion duct 4, passing only through the first air filter 6, and - the motor-fan unit 5 is operating at its maximum electrical power.

[0049] This first operating mode can, for example, be configured to activate automatically when at least one passenger is present in the vehicle and when the temperature inside the passenger compartment H exceeds a predetermined threshold temperature (for example, between 35 and 40°C). It is also conceivable that this first operating mode could be activated manually by a passenger in the vehicle.

[0050] The second HEPA filter 8 is therefore bypassed when this first operating mode is activated (the entire airflow passes through the first bypass duct 9 which offers no resistance to the passage of air unlike the filtration duct 7), so that pressure losses are contained and a sufficient air flow into the passenger compartment (approximately 500 kg / h) can be obtained without oversizing the motor-fan unit 5 (and therefore with limited electrical consumption as well as reduced operating cost and noise).

[0051] In this first mode of operation, the second airflow control flap 12 advantageously occupies its first position in which the outlet of the duct recirculation 3 is blocked, so as to reduce the intensity of the extraneous noises generated in the passenger compartment H.

[0052] The supervisory module is also capable of operating the vehicle's air handling HVAC system 1 in a second mode known as "pre-conditioning" illustrated in [Fig. 3], in which: - the first airflow control flap 11 occupies its second position and the second airflow control flap 12 occupies its first position, so that the pulsed air, entering the passenger compartment H and coming solely from outside E of the vehicle, circulates successively through the outside air intake duct 2, the filtration duct 7, the second bypass duct 10 and the diffusion duct 4, passing successively through the second HEPA air filter 8 and the first air filter 6; and - the motor-fan unit 5 is operating at its maximum electrical power.

[0053] This second operating mode can, for example, be configured to activate automatically when there are no passengers in the vehicle and when the temperature inside the passenger compartment H exceeds a predetermined threshold temperature (advantageously the same as that associated with the activation of the first operating mode, known as "rapid cooling," so that the two modes alternate automatically). It is also conceivable that this second operating mode could be activated manually by a passenger in the vehicle.

[0054] This second mode of operation thus makes it possible to cool the passenger compartment H before passengers enter the vehicle while maintaining optimal filtration quality.

[0055] The reduction in airflow into the passenger compartment caused by the greater pressure losses generated by passing through this second HEPA 8 air filter naturally results in slower cooling compared to the first operating mode. However, this is not problematic in this case, considering that there is no imperative to reach a bearable temperature in the passenger compartment as quickly as possible (which is obviously the case when at least one passenger is present).

[0056] The supervisory module is further capable of operating the vehicle's HVAC air handling system 1 in a third mode, known as "thermal convergence," illustrated in [Fig. 4], in which the first airflow control flap 11 is in its third position and the second airflow control flap 12 is in its second position, so that the supply air entering the passenger compartment H, consisting solely of recirculated air, flows successively through the recirculation duct 3 and the filtration duct 7 (the airflow in this duct flowing in the opposite direction to that in the first mode). the second mode of operation), the first bypass duct 9 and the diffusion duct 4 passing successively through the second HEPA air filter 8 and the first air filter 6.

[0057] This third operating mode, designed to converge the temperature in the passenger compartment H towards a predefined setpoint temperature, can, for example, be configured to activate automatically when at least one passenger is present in the vehicle and when the temperature inside the passenger compartment H is less than or equal to a predetermined threshold temperature (advantageously the same as that associated with the activation of the first operating mode, known as "rapid cooling," so that the two modes alternate automatically). It is also conceivable that this third operating mode could be activated manually by a passenger in the vehicle.

[0058] This third operating mode also ensures optimal filtration quality. Since the difference between the interior temperature of the passenger compartment H and the setpoint temperature is less than in the first operating mode, the reduction in airflow into the passenger compartment caused by the greater pressure losses generated by passing through this second HEPA 8 air filter is no longer problematic.

[0059] Preferably, the face of this second HEPA 8 air filter which is first passed through by the airflow in the second operating mode known as "pre-conditioning" (illustrated by [Fig.3]) is covered with an anti-static pre-filter 8A intended to retain the largest of the aspirated particles from the outside air, so as to prevent this HEPA 8 filter from becoming saturated or obstructed too quickly.

[0060] In order to reduce operating noise, the monitoring module will advantageously be configured so as to progressively reduce the electrical power of the motor-fan group 5 as the differential between the temperature inside the passenger compartment H and the outside temperature decreases.

[0061] Many embodiments are of course conceivable and it is recalled in this regard that the present invention is not limited to the embodiments described and represented, but also encompasses all the execution variants within the reach of a person skilled in the art.

Claims

Demands

1. Air treatment system (1) for a motor vehicle comprising an outside air intake duct (2), a passenger compartment air recirculation duct (3), a diffusion duct (4) opening into the passenger compartment (H) of said vehicle and housing a motor-fan unit (5) and a first air filter (6);characterized in that it also comprises: - a two-way flow filtration duct (7) housing a second HEP A type air filter (8) and extending between the outlet of said inlet duct (2) and the outlet of said recirculation duct (3), - a first bypass duct (9) extending between the outlet of said inlet duct (2) and the inlet of the diffusion duct (4), and - a second bypass duct (10) extending between the outlet of said recirculation duct (3) and the inlet of said diffusion duct (4), said system further comprising: - a first airflow control flap (11) arranged at the interface between the outlet of said inlet duct (2), a first inlet / outlet of said filtration duct (7) and the inlet of said first bypass duct (9);and - a second airflow control flap (12), arranged at the interface between the outlet of said recirculation duct (3), the second inlet / outlet of said filtration duct (7) and the inlet of said second bypass duct (10).;

2. Air handling system (1) according to claim 1, characterized in that said first pilot flap (11) is movable between: - a first position in which said inlet duct (2), said first bypass duct (9) and said filtration duct (7) are fluidly connected; - a second position in which only said inlet ducts (2) and filtration duct (7) are fluidly connected while the inlet of said first bypass duct (9) is closed; and - a third position in which only said filtration duct (7) and said first bypass duct (9) are connected fluidically while the outlet of said inlet duct (2) is closed; said second pilot flap (12) being movable between: - a first position in which only said filtration duct (7) and said second bypass duct (10) are fluidically connected, while the outlet of said recirculation duct (3) is closed; and - a second position in which only said recirculation duct (3) and filtration duct (7) are fluidly connected, while the inlet of said second bypass duct (10) is closed.

3. Air treatment system (1) according to claim 2, characterized in that it is capable of operating in a first mode in which: - said first pilot flap (11) occupies its first position so that the pulsed air, entering the passenger compartment (H) and coming only from outside (E) the vehicle, circulates successively in said intake duct (2), said first bypass duct (9) and said diffusion duct (4) passing only through said first air filter (6), and - said motor-fan unit (5) operates at its maximum electrical power.

4. Air handling system (1) according to claim 3, characterized in that said first mode of operation is configured to activate automatically in the presence of at least one passenger in the vehicle and when the temperature inside the passenger compartment (H) is above a predetermined threshold temperature.

5. Air handling system (1) according to any one of claims 2 to 4, characterized in that it is capable of operating in a second mode in which: - said first pilot flap (11) is in its second position and said second pilot flap (12) is in its first position, so that the pulsed air, entering the passenger compartment (H) and coming only from outside (E) the vehicle, flows successively through said intake duct (2), said filtration duct (7), said second bypass duct (10) and said diffusion duct (4) passing successively through said second HEPA air filter (8) and said first air filter (6); and - said motor-fan unit (5) operates at its maximum electrical power.

6. Air treatment system (1) according to claim 5, characterized in that said second mode is configured to activate automatically in the absence of a passenger in the vehicle and when the temperature inside the passenger compartment (H) is above a predetermined threshold temperature.

7. Air handling system (1) according to any one of claims 5 or 6, characterized in that the face of said second HEPA air filter (8) first crossed by the airflow in said second mode of operation is covered with an antistatic pre-filter (8A).

8. Air handling system (1) according to any one of claims 2 to 7, characterized in that it is capable of operating in a third mode in which said first pilot flap (11) occupies its third position and said second pilot flap (12) occupies its second position, so that the pulsed air, entering the passenger compartment (H) and consisting solely of recycled air, circulates successively in said recirculation duct (3), said filtration duct (7), said first bypass duct (9) and said diffusion duct (4) passing successively through said second HEPA air filter (8) and said first air filter (6).

9. Air handling system (1) according to claim 8, characterized in that said third mode of operation is configured to activate automatically in the presence of at least one passenger in the vehicle and when the temperature inside the passenger compartment (H) is less than or equal to a predetermined threshold temperature.

10. Motor vehicle comprising an air treatment system (1) according to any one of claims 1 to 9.

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