Automotive air treatment system equipped with a HEPA filter

Abstract

The invention relates to a vehicle air treatment system (1) comprising an outside air intake duct (2), a passenger compartment air recirculation duct (3), a diffusion duct (4) opening into the passenger compartment (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, as well as at least one first airflow control flap (7) 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 fluidly connected and a closed position in which said recirculation and diffusion ducts are fluidly connected; characterized in that it comprises a second HEPA type air filter (8) mounted in said recirculation 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 motor vehicles equipped with a HEPA type air filter (for "High Efficiency Particles Arresting" in English, which translates into French as [filter] with high efficiency against airborne particles). 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 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.

[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 forced 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 forced 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 US10525395B2, 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 are generally installed in the engine compartment of the vehicle located under the front hood.

[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 (on the order of 10 to 20%). Description of the invention

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

[0018] It proposes for this purpose an air treatment system for motor vehicles 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 is arranged a motor-fan unit, at least one first air filter mounted in said outside air intake duct, as well as at least one first airflow 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 fluidly connected and a closed position in which said recirculation and diffusion ducts are fluidly 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 avoid the latter being stressed when the motor-fan unit generating blown air in the passenger compartment is supplied with outside air, in order in particular 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.

[0020] According to preferred characteristics of said air treatment system according to the invention: - said air treatment system includes a second airflow 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; - said air treatment system is capable of operating in a rapid cooling mode in which said first pilot flap is in its open position so that the blown 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 airflow enters the passenger compartment; - said second control flap, open by default, is configured to occupy its closed position when said rapid cooling mode is activated; - said rapid cooling mode is configured to activate automatically when the temperature inside the passenger compartment is above a predetermined threshold temperature; - said air handling system is capable of operating in a thermal convergence mode in which said first pilot damper is in its closed position so that the blown air entering the passenger compartment is solely recycled air that has passed through said second HEPA filter; - said thermal convergence mode is configured to activate automatically when the temperature inside the passenger compartment is less than or equal to a predetermined threshold temperature; - said second HEPA filter is class H13; and / or - 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. Brief description of the drawings

[0022] The disclosure 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, in which [Fig. 1] shows a schematic view of an HVAC air handling system according to the invention for a motor vehicle. Description of embodiments

[0023] Intended to be installed in the engine compartment of a motor vehicle, the HVAC air treatment system 1 schematically illustrated in [Fig. 1] 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 vehicle's passenger compartment H; and - a diffusion conduit 4 whose outlet is fluidically connected to the interior of the vehicle's passenger compartment H.

[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 airflow in these ducts 2, 3 and 4.

[0025] The HVAC air handling system 1 also includes 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.

[0026] This first cabin 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 10 pm (PM 10).

[0027] This first filter 6 can also consist of a simple pollen filter, an activated carbon filter for filtering and neutralizing odors, or even a A polyphenol filter provides more effective allergen filtration. This filter 6 can also consist of multiple layers, each layer performing the function of one of the filters defined previously.

[0028] The HVAC air handling system 1 further includes a first airflow 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.

[0029] This first control flap 7 is movable via a motorized actuator not shown between: - an open position in which the intake ducts 2 and the diffusion duct 4 are fluidly connected so that the forced air entering the passenger compartment H comes solely from outside the vehicle E, and - a closed position in which the recirculation ducts 3 and diffusion ducts 4 are fluidly connected so that the forced air entering the passenger compartment H is only recycled air.

[0030] This control flap 7 can also advantageously occupy at least one intermediate position between its open and closed positions, so that the blown air entering the passenger compartment consists of a mixture of air from outside the vehicle and recycled air (so-called "partial recirculation" configuration).

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

[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).

[0033] 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).

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

[0035] This second HEPA filter 8 is also advantageously located in the vehicle's engine compartment 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.

[0036] The HVAC air handling system 1 also includes a supervisory module (not shown) capable of managing, autonomously or according to commands commands transmitted by the vehicle's passengers, the operation of the motor-fan unit 5 in order to adapt the flow of air coming out of it, as well as the operation of the first air flow control flap 7.

[0037] 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.

[0038] This supervisory module is capable of operating the vehicle's HVAC air handling system 1 in a rapid cooling mode in which: - the first pilot flap 7 is in its open position so that the blown air entering the passenger compartment H comes only from outside the vehicle E, and - the motor-fan unit 5 operates at its maximum electrical power so that a maximum airflow enters this passenger compartment H.

[0039] This rapid cooling mode can, for example, be configured to activate automatically when the temperature inside the passenger compartment exceeds a predetermined threshold temperature (for example, between 35 and 40°C). It is also conceivable that this rapid cooling mode could be activated manually by a vehicle passenger.

[0040] Due to the positioning of the second HEPA filter 8 in the recirculation duct 3, it is therefore not stressed when this rapid cooling mode is activated 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).

[0041] The HVAC air handling system 1 also includes a second airflow control flap 10 arranged in the recirculation duct 3 upstream of the second HEPA 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.

[0042] This second airflow 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 generated parasitic noises.

[0043] The supervisory module is also capable of operating the vehicle's air handling HVAC system 1 in a thermal convergence mode in which the first pilot flap 7 is in its closed position so that the blown air entering the passenger compartment H is only recycled air that has passed through the second HEPA 8 filter.

[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 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 rapid cooling mode). It is also conceivable that this rapid thermal convergence mode could be activated manually by a vehicle passenger.

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

[0046] Since the difference between the interior temperature of the passenger compartment H and the setpoint temperature is less than in the rapid cooling mode, the reduction in airflow into the passenger compartment caused by the greater pressure losses generated by passing through this second HEPA 8 filter is no longer problematic.

[0047] The surface dimensions of this second HEPA filter can thus be reduced compared to the HEPA filters used in current vehicles and approach those of high efficiency (HE) filters by being for example between 5 and 10 dm2, which allows a significant space saving facilitating their installation in the vehicle's engine compartment.

[0048] 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.

[0049] According to alternative embodiments not shown, the air treatment system according to the invention may, for example, be devoid of the second airflow control flap such as 10.

[0050] 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 embodiments 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 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), and at least one first airflow 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 duct (2) and diffusion duct (4) are fluidly connected and a closed position in which said recirculation duct (3) and diffusion duct (4) are fluidly connected;characterized in that it comprises a second HEPA type air filter (8) mounted in said recirculation duct (3), and in that it comprises a second airflow 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.;

2. Air handling system (1) according to claim 1, characterized in that it is capable of operating in a rapid cooling mode in which: - said first pilot flap (7) is in its open position so that the blown 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 airflow enters the passenger compartment (H).

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

4. Air handling system (1) according to any one of claims 2 or 3, characterized in that said rapid cooling mode is configured to activate automatically 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 1 to 4, characterized in that it is capable of operating in a thermal convergence mode in which said first pilot flap (7) occupies its closed position so that the blown air entering the passenger compartment (H) is only recycled air having passed through said second HEP A filter (8).

6. Air handling system (1) according to claim 5, characterized in that said thermal convergence mode is configured to activate automatically when the temperature inside the passenger compartment (H) is less than or equal to a predetermined threshold temperature.

7. Air handling system (1) according to any one of claims 1 to 6, characterized in that said second HEPA filter (8) is of class H13.

8. Air treatment system (1) according to any one of claims 1 to 7, characterized in that the upstream face of said second HEPA filter (8) is covered with an antistatic pre-filter (9).

9. Motor vehicle comprising an air treatment system (1) according to any one of claims 1 to 8.