Air treatment system for a motor vehicle, which system is provided with a hepa filter

Abstract

The invention relates to an air treatment system (1) for a vehicle comprising an outside air intake duct (2), a passenger-compartment air recirculation duct (3), a diffusion duct (4) which leads to the passenger compartment (H) and in which a motor-fan unit (5) is arranged, at least one first air filter (6) mounted in the outside air intake duct, and at least one first air flow control flap (7) arranged at the interface between the outlet of the intake duct, the outlet of the recirculation duct and the inlet of the diffusion duct, the first flap being movable between an open position in which the intake duct and the diffusion duct are fluidically connected and a closed position in which the recirculation duct and the diffusion duct are fluidically connected. The air treatment system is characterised in that it comprises a second, HEPA-type air filter (8) mounted in the recirculation duct.

Description

[0001] Description

[0002] Title of the invention: Air treatment system for a motor vehicle provided with a HEPA filter

[0003] [Technical field]

[0004] [1] The present invention claims priority from French application 2305186 filed on May 25, 2023, the content of which (text, drawings and claims) is incorporated herein by reference. The present invention relates generally to air treatment systems within the passenger compartment of motor vehicles.

[0005] [2] The invention relates in particular to such an air treatment system for a motor vehicle provided with a HEPA type air filter (for “High Efficiency Particulates Arresting” in English, translating into French as [filter] with high efficiency against airborne particles).

[0006] [Earlier technique]

[0007] [3] As is known, a motor vehicle includes an air treatment system within the passenger compartment of this vehicle in order to ensure passenger comfort.

[0008] [4] Generally referred to by the acronym HVAC (for Heating, Ventilation and Air-Conditioning in English), such an air treatment system typically includes:

[0009] - an external air intake duct whose inlet is fluidically connected to the exterior of the vehicle;

[0010] - a passenger compartment air recirculation duct whose inlet is fluidically connected to the interior of the vehicle passenger compartment; and

[0011] - a diffusion duct whose outlet is fluidically connected to the interior of the vehicle's passenger compartment.

[0012] [5] The HVAC air treatment system also comprises a motor-fan unit arranged in said diffusion duct, as well as at least one first air filter mounted in the outside air intake duct or in the diffusion duct. [6] Such an HVAC air treatment system further comprises an air flow 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.

[0013] [7] This control flap is movable between an open position in which said exterior air intake and diffusion ducts are fluidically connected so that the pulsed air entering the passenger compartment comes only from outside the vehicle, and a closed position in which said recirculation and diffusion ducts are fluidically connected so that the pulsed air entering the passenger compartment is only recycled air.

[0014] [8] The actuation of this air flow control flap can generally be controlled either manually by the driver or front passenger via mechanical or tactile control devices, or automatically via the HVAC air treatment system supervision module.

[0015] [9] In order to improve the quality of the cabin air, it is also known, in particular from US10525395B2, to have a HEPA type air filter (for “High Efficiency Particulates Arresting” in English, translating into French as [filter] with high efficiency against airborne particles) in the exterior air intake duct.

[0016]

[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).

[0017]

[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 dm 2 , so they are generally located in the engine compartment of the vehicle located under the front hood.

[0018]

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

[0019]

[0013] This electrical power proves to be particularly important during the rapid cooling phases initiated for example when starting vehicles with a very high passenger compartment temperature resulting from prolonged exposure in the summer to direct sunlight.

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

[0020]

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

[0021]

[0016] In addition to the additional cost and the increase in operating noise generated by this oversizing of the motor-fan unit, the major drawback of installing such a HEPA filter lies in the excess electrical consumption generated, this criterion being particularly sensitive in the case of electric vehicles for which the loss of autonomy can prove relatively significant (of the order of 10 to 20%).

[0022] [Statement of the invention]

[0023]

[0017] The present invention therefore aims to improve the situation.

[0024]

[0018] To this end, it proposes an air treatment system for a motor vehicle comprising an outside air intake duct, a passenger compartment air recirculation duct, a diffusion duct opening into the passenger compartment of said vehicle and in which a motor-fan unit is arranged, at least one first air filter mounted in said outside air intake duct, as well as at least one first air flow control flap arranged at the interface between the outlet of said intake duct, that of said recirculation duct and the inlet of said diffusion duct, said first flap being movable between an open position in which said intake and diffusion ducts are fluidically connected and a closed position in which said recirculation and diffusion ducts are fluidically connected; characterized in that it comprises a second HEPA type air filter mounted in said recirculation duct.

[0019] This particular positioning of the second HEPA type air filter makes it possible to prevent the latter from being used when the motor-fan unit generating air pulsed into the passenger compartment is supplied with outside air, in particular so as to limit pressure losses and to optimize electrical consumption in the rapid cooling phases where the motor-fan unit operates at its maximum electrical power.

[0025]

[0020] According to preferred characteristics of said air treatment system according to the invention:

[0026] - said air treatment system comprises a second air flow control flap arranged in said recirculation duct upstream of said second HEPA filter and movable between a default open position in which this recirculation duct is fully open and a closed position in which this same recirculation duct is closed;

[0027] - said air treatment system is capable of operating in a rapid cooling mode in which said first control flap occupies its open position so that the pulsed air entering the passenger compartment comes only from outside the vehicle and said motor-fan unit operates at its maximum electrical power so that a maximum air flow enters the passenger compartment;

[0028] - said second control flap, open by default, is configured to occupy its closed position when said rapid cooling mode is activated;

[0029] - said rapid cooling mode is configured to activate automatically when the temperature within the passenger compartment is higher than a predetermined threshold temperature;

[0030] - said air treatment system is capable of operating in a thermal convergence mode in which said first control flap occupies its closed position so that the pulsed air entering the passenger compartment is only recycled air having passed through said second HEPA filter;

[0031] - said thermal convergence mode is configured to activate automatically when the temperature within the passenger compartment is less than or equal to a predetermined threshold temperature;

[0032] - said second HEPA filter is of class H13; and / or

[0033] - the upstream face of said second HEPA filter is covered with an antistatic pre-filter.

[0021] The invention also relates, in a second aspect, to a motor vehicle comprising such an air treatment system.

[0034] [Brief description of the drawings]

[0035]

[0022] The description of the invention will now be continued by the detailed description of several exemplary embodiments, given below for illustrative but non-limiting purposes, with reference to the appended drawings, in which [Fig 1] represents a schematic view of an HVAC air treatment system according to the invention for a motor vehicle.

[0036] [Detailed description]

[0037]

[0023] Intended to be installed in the engine compartment of a motor vehicle, the HVAC air treatment system 1 illustrated schematically in FIG. 1 comprises:

[0038] - an external air intake duct 2 whose inlet is fluidically connected to the exterior E of the vehicle;

[0039] - a passenger compartment air recirculation duct 3 whose inlet is fluidically connected to the interior of the passenger compartment H of the vehicle; and

[0040] - a diffusion duct 4 whose outlet is fluidically connected to the interior of the passenger compartment H of the vehicle.

[0041]

[0024] 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 circulation of the air flow in these ducts 2, 3 and 4.

[0042]

[0025] The HVAC air treatment system 1 also comprises a motor-fan unit 5 arranged in the diffusion duct 4, as well as a first cabin air filter 6 mounted in the intake duct 2 and responsible for retaining certain polluting particles suspended in the outside air.

[0043]

[0026] This first cabin air filter 6 is advantageously constituted by 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 10 pm (PM 10).

[0027] This first filter 6 can also be constituted by a simple pollen filter, an activated carbon filter making it possible to filter and neutralize odors, or even a Polyphenol filter ensuring more effective filtering of allergens. This filter 6 can also be constituted by a plurality of layers, each layer performing the function of one of the filters defined previously.

[0044]

[0028] The HVAC air treatment system 1 further comprises a first air flow control flap 7 arranged at the interface between the outlet of the intake duct 2, the outlet of the recirculation duct 3 and the inlet of the diffusion duct 4.

[0045]

[0029] This first control flap 7 is movable via a motorized actuator not shown between:

[0046] - an open position in which the intake ducts 2 and diffusion ducts 4 are fluidically connected so that the pulsed air entering the passenger compartment H comes only from the exterior E of the vehicle, and

[0047] - a closed position in which the recirculation ducts 3 and diffusion ducts 4 are fluidically connected so that the pulsed air entering the passenger compartment H is only recycled air.

[0048]

[0030] This control flap 7 can also advantageously occupy at least one intermediate position between its opening and closing positions, so that the pulsed air entering the passenger compartment is constituted by a mixture of air coming from the exterior E of the vehicle and recycled air (so-called configuration of

[0049] “partial recirculation).

[0050]

[0031] According to the invention, the HVAC air treatment system 1 also comprises a second HEPA 8 type cabin air filter mounted in the cabin air recirculation duct 3.

[0051]

[0032] This second HEPA 8 filter is advantageously of class H13 so as to ensure the filtering 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).

[0052]

[0033] According to alternative embodiments, this second HEPA filter 8 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).

[0034] Preferably, the upstream face of this second HEPA filter 8 is covered with an antistatic pre-filter 9 intended to retain the largest of the sucked-up particles, so as to prevent this HEPA filter 8 from becoming too quickly saturated or obstructed.

[0053]

[0035] This second HEPA filter 8 is also advantageously installed in the engine compartment of the vehicle located under the front hood, so that the passenger compartment air recirculation ducts 3 and diffusion ducts 4 pass through the bulkhead, not shown, separating the engine compartment and the passenger compartment.

[0054]

[0036] The HVAC air treatment system 1 also comprises a supervision module (not shown) capable of managing, autonomously or according to control orders transmitted by the passengers of the vehicle, the operation of the motor-fan unit 5 in order to adapt the flow of pulsed air leaving the latter as well as the operation of the first air flow control flap 7.

[0055]

[0037] Preferably consisting of the vehicle's BSI (for "Intelligent Service Box") also called VSM (for "Vehicle Supervisor Module" in English) in common terminology, this supervision module comprises a computer equipped with one or more interconnected microprocessors, as well as a memory module comprising non-volatile and non-volatile memory.

[0056]

[0038] This supervision module is capable of operating the HVAC air treatment system 1 of the vehicle in a rapid cooling mode in which:

[0057] - the first control flap 7 occupies its open position so that the pulsed air entering the passenger compartment H comes only from the exterior E of the vehicle, and

[0058] - the motor-fan unit 5 operates at its maximum electrical power so that a maximum air flow enters this passenger compartment H.

[0059]

[0039] This rapid cooling mode can for example be configured to activate automatically when the temperature within the passenger compartment is higher than a predetermined threshold temperature (for example between 35 and 40°C). It is also possible to envisage that this rapid cooling mode can be activated manually by a passenger of the vehicle.

[0060]

[0040] Due to the positioning of the second HEPA filter 8 in the recirculation duct 3, the latter is therefore not used when this rapid cooling mode is activated so that the pressure losses are contained and a sufficient air flow rate at the passenger compartment inlet (approximately 500 kg / h) can be obtained without oversizing the motor-fan unit 5 (and therefore with limited electrical consumption as well as reduced cost and operating noise).

[0061]

[0041] The HVAC air treatment system 1 also comprises a second air flow control flap 10 arranged in the recirculation duct 3 upstream of the second H EPA filter 8 and movable, via a motorized actuator not shown, between a default open position in which this recirculation duct 3 is fully open and a closed position in which this same recirculation duct 3 is closed.

[0062]

[0042] This second air flow control flap 10, open by default, is configured to occupy its closed position when the rapid cooling mode is activated, so as to reduce the intensity of the parasitic noise generated.

[0063]

[0043] The supervision module is also capable of operating the HVAC air treatment system 1 of the vehicle in a thermal convergence mode in which the first control flap 7 occupies its closed position so that the pulsed air entering the passenger compartment H is only recycled air having passed through the second H EPA filter 8.

[0064]

[0044] This thermal convergence mode configured to reach a predefined setpoint temperature in the passenger compartment H, can for example be activated automatically when the temperature within the passenger compartment H is less than or equal to a predetermined threshold temperature (advantageously the same as that associated with the triggering of the rapid cooling mode). It is also possible to envisage that this rapid thermal convergence mode can be activated manually by a passenger of the vehicle.

[0065]

[0045] In this thermal convergence mode where the second air flow control flap 10 is open, the second HEPA filter 8 is used so as to ensure optimal air quality in the passenger compartment H.

[0066]

[0046] The differential between the interior temperature of the passenger compartment H and the set temperature being less than in the rapid cooling mode, the reduction in the air flow rate at the passenger compartment inlet caused by the more significant pressure losses generated by the passage of this second HEPA filter 8 is no longer problematic.

[0047] The surface dimensions of this second HEPA filter can thus be reduced in comparison with the HEPA filters used in current vehicles and approach those of high efficiency (HE) filters by being for example between 5 and 10 dm 2 , which allows a significant saving of space, facilitating their installation in the engine compartment of the vehicle.

[0067]

[0048] In order to reduce the operating noise, the supervision module will advantageously be configured so as to progressively reduce the electrical power of the motor-fan unit 5 as the differential between the temperature within the passenger compartment H and the outside temperature decreases.

[0049] According to alternative embodiments not shown, the air treatment system according to the invention may for example be without the second air flow control flap such as 10.

[0068]

[0050] Many variant embodiments are of course conceivable and it is recalled in this respect that the present invention is not limited to the embodiments described and shown, but also encompasses all variant embodiments within the reach of those skilled in the art, i

Claims

Claims

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 of said vehicle (H) and in which is arranged a motor-fan unit (5), at least one first air filter (6) mounted in said outside air intake duct (2), as well as at least one first air flow control flap (7) arranged at the interface between the outlet of said intake duct (2), that of said recirculation duct (3) and the inlet of said diffusion duct (4), said first flap (7) being movable between an open position in which said intake (2) and diffusion (4) ducts are fluidically connected and a closed position in which said recirculation (3) and diffusion (4) ducts are fluidically connected;characterized in that it comprises a second HEPA type air filter (8) mounted in said recirculation duct (3).;

2. Air treatment system (1) according to claim 1, characterized in that it comprises a second air flow control flap (10) arranged in said recirculation duct (3) upstream of said second HEPA filter (8) and movable between a default open position in which this recirculation duct (3) is fully open and a closed position in which this same recirculation duct (3) is closed.

3. Air treatment system (1) according to one of claims 1 or 2, characterized in that it is capable of operating in a rapid cooling mode in which: - said first control flap (7) occupies its open position so that the pulsed air entering the passenger compartment (H) comes only from outside the vehicle, and - said motor-fan unit (5) operates at its maximum electrical power so that a maximum air flow enters the passenger compartment (H).

4. Air treatment system (1) according to claims 2 and 3, characterized in that said second control flap (10), open by default, is configured to occupy its closed position when said rapid cooling mode is activated.

5. Air treatment system (1) according to one of claims 3 or 4, characterized in that said rapid cooling mode is configured to activate automatically when the temperature within the passenger compartment (H) is higher than a predetermined threshold temperature.

6. Air treatment system (1) according to one of claims 1 to 5, characterized in that it is capable of operating in a thermal convergence mode in which said first control flap (7) occupies its closed position so that the pulsed air entering the passenger compartment (H) is only recycled air having passed through said second HEPA filter (8).

7. Air treatment system (1) according to claim 6, characterized in that said thermal convergence mode is configured to activate automatically when the temperature within the passenger compartment (H) is less than or equal to a predetermined threshold temperature.

8. Air treatment system (1) according to one of claims 1 to 7, characterized in that said second HEPA filter (8) is of class H13.

9. Air treatment system (1) according to one of claims 1 to 8, characterized in that the upstream face of said second HEPA filter (8) is covered with an antistatic pre-filter (9).

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

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