FR3100314A1 - Method and device for disinfecting a motor vehicle air conditioning system - Google Patents

Abstract

The invention relates to a method for disinfecting by ultraviolet radiation an element of an air conditioning system (1) of a motor vehicle, such as an air filter (12), the method using a disinfection device (14). ) by ultraviolet radiation comprising a set of light-emitting diodes (142) divided into at least two groups, the method comprising the step of successively activating the ignition of each of the groups of diodes making up the set of light-emitting diodes (142 ), so that the intensity of the electric current necessary to supply all the light-emitting diodes (142) lit simultaneously is less than or equal to a threshold value, each group of light-emitting diodes (142) being activated for a period of time greater than or equal to a minimum exposure time. Figure for the abstract: Fig. 1

Description

Method and device for disinfecting a motor vehicle air conditioning system

The invention relates to the field of motor vehicle heating/air conditioning equipment, and relates more specifically to the disinfection of such assemblies.

Air conditioning is a comfort element that is increasingly being installed in motor vehicles. In known manner, an air conditioning device for a motor vehicle comprises four main elements: a compressor, a condenser, an expansion valve, and an evaporator. These four elements are arranged within a closed circuit in which a refrigerant fluid (or refrigerant fluid) circulates. An air filter is placed upstream of the evaporator in order to filter the air to be treated before it crosses the evaporator. The air filter and the evaporator are particularly sensitive components from the point of view of the development of microorganisms due to the humidity and temperature conditions that are particularly favorable to their development.

In order to guarantee that the passenger compartment of a motor vehicle is not contaminated by microorganisms developing within the air conditioning device, it is known to provide a disinfection device implementing light sources of the light-emitting diode type emitting rays ultraviolet type C (or UVc). UVc rays are known for their bactericidal and fungicidal effectiveness, being for example widely used in the medical and food fields.

It is known to provide a disinfection device by ultraviolet radiation in an air conditioning system. However, to effectively treat an air filter, the disinfection device must cover the entire surface to be treated, which requires a large number of light-emitting diodes (typically several dozen). In the case of filters comprising pleats, this requires an even greater number of light-emitting diodes, with specific orientations in order to correctly treat the bottom of the cavities formed by the pleats.

Furthermore, the power of the light-emitting diodes must be sufficient to obtain a satisfactory antibacterial effect, but the more powerful they are, the higher their consumption. On the other hand, the higher the power of the light-emitting diodes, the less the exposure time required to treat a surface. It is therefore advantageous to have light-emitting diodes of relatively high power. However, the total consumption must remain below a certain limit, since the electricity consumption allocated to the various equipment of a vehicle is necessarily limited.

The object of the present invention is to remedy the drawbacks of the state of the art, and more particularly those exposed above, by proposing a method for disinfecting a component of a motor vehicle air conditioning system by exposure to ultraviolet radiation. which is efficient while limiting instantaneous electricity consumption.

To this end, the invention relates to a method for disinfection by ultraviolet radiation of an element of a motor vehicle air conditioning system, such as an air filter, the method implementing a device for disinfection by ultraviolet radiation comprising a set of light-emitting diodes divided into at least two groups, the method comprising the step of successively activating the ignition of each of the groups of diodes making up the set of light-emitting diodes, so that the intensity of the electric current necessary for supplying the set of light-emitting diodes lit simultaneously is less than or equal to a threshold value, each group of light-emitting diodes being activated for a period greater than or equal to a minimum exposure time.

Thus, by dividing the light-emitting diodes into different groups which are activated sequentially, the intensity of the current necessary to supply all the light-emitting diodes lit simultaneously is limited. This avoids lighting all the diodes simultaneously, while maintaining a sufficient lighting time for each of the diodes. Thus, the element to be disinfected sees its entire surface exposed to ultraviolet radiation, and this for a sufficient duration for each portion of this surface, while limiting instantaneous electricity consumption.

In one embodiment, only one group of light emitting diodes is activated at a time.

In one embodiment, the set of light-emitting diodes is divided into at least three groups, two groups of diodes being lit simultaneously.

In one embodiment, each group is distinct from the adjacent group.

In one embodiment, at least two groups are nested together.

In one embodiment, the light-emitting diodes all have the same nominal power.

In one embodiment, the threshold value is between 1 and 2.5 A, preferably between 1.5 and 2.5 A, and for example equal to 2 A.

The invention also relates to a device for disinfection by ultraviolet radiation of an element of a motor vehicle air conditioning system, the device comprising a set of light-emitting diodes and a controller arranged to implement the method as defined above. .

The invention also relates to an air conditioning system for a motor vehicle comprising an air filter and a disinfection device in accordance with that defined above, the disinfection device being arranged opposite the air filter.

The invention also relates to a motor vehicle comprising an air conditioning system as defined above.

The present invention will be better understood on reading the following detailed description, made with reference to the accompanying drawings, in which:

FIG. 1 represents part of an air conditioning system for a motor vehicle comprising a device for disinfection by ultraviolet radiation.

FIG. 2 represents a first example of sequential lighting of the light-emitting diodes in accordance with the invention.

FIG. 3 represents a second example of sequential lighting of the light-emitting diodes in accordance with the invention.

FIG. 4 represents a third example of sequential lighting of the light-emitting diodes in accordance with the invention.

FIG. 1 represents a portion of an air conditioning system 1 on board a motor vehicle. The air conditioning system 1 comprises a closed circuit in which a refrigerant fluid circulates, the circuit comprising in particular a compressor, a condenser, an expansion valve and an evaporator (not shown). The air conditioning system 1 comprises a duct 10 to bring the air to be cooled to the evaporator. In the conduit 10, upstream of the evaporator, is placed an air filter 12, in order to eliminate the foreign bodies present in the air before it passes through the evaporator.

In order to carry out a disinfection treatment of the air filter by exposure to ultraviolet radiation, the air conditioning system 1 comprises a disinfection device 14. The disinfection device 14 is arranged in the conduit 10, facing the air filter 12. The disinfection device comprises a support 140 on which is fixed a plurality of light-emitting diodes 142. The number and arrangement of the light-emitting diodes 142 makes it possible to treat the entire surface of the air filter 12. In the example of the figure 1, four rows of eight light-emitting diodes 142 are provided. The device 14 also comprises a controller 144 making it possible to control the switching on of the various diodes of the disinfection device.

A description is given below, in relation to FIGS. 2 to 4, of embodiments of a disinfection process in accordance with the invention.

In Figures 2 to 4, there is shown a disinfection device 14 comprising forty-eight light-emitting diodes, arranged in four rows of twelve diodes. In the example of Figures 2 to 4, the light-emitting diodes all have an identical nominal power, this power being such that the total electrical consumption of the disinfection device 14 when all the diodes are on exceeds the maximum intensity available. For example, if the light-emitting diodes 142 each have a nominal power such that their operation requires an intensity of 50 milliamperes, then the total intensity necessary for the supply of the 48 diodes reaches 2.4 amperes, which is too high in view of the intensity allocated to such equipment (which is generally between 1 and 2 amps). In order to allow effective disinfection while limiting electrical consumption, the method in accordance with the invention provides for sequential lighting of the diodes, in order to achieve optimal disinfection (in terms of surface area of exposure and duration of exposure) while remaining below a given intensity limit of the electric current supplying the disinfection device.

In Figure 2, there is shown a first embodiment of the method of the invention. In the example of Figure 2, the 48 light-emitting diodes 142 integrated into the panel 140 of the disinfection device 14 are divided into six groups A, B, C, D, E, F of eight adjacent diodes. Thus, as visible in FIG. 2, the first group A comprises the first two diodes of each of the four rows, the group B comprises the next two diodes of each of the four rows, etc. In accordance with the invention, the disinfection is carried out with a sequential ignition of the different groups of diodes, so that each diode remains lit for a sufficient time for optimal exposure of the surface to be disinfected. For example, the ignition of the different groups can be as follows:

• simultaneous ignition of groups A, B, C for a first duration d equal for example to one hour; Then
• simultaneous ignition of groups B, C, D for a duration equal to the first duration d; Then
• simultaneous ignition of groups C, D, E for a duration equal to the first duration d; Then
• simultaneous ignition of groups D, E, F for a duration equal to the first duration d.

Thus, this sequential ignition makes it possible to carry out the disinfection of the entire surface to be treated with a sufficient exposure time for each diode, while remaining below an electrical consumption limit. We can see that at a given moment, there are never more than 24 diodes lit simultaneously. Taking the example given above with diodes with a power of 50 milliwatts, we obtain a total consumption of 1.2 A (which is well below the limit of 2 A). The exposure time required for each portion of the surface of the element to be treated obviously depends on the nominal power of the light-emitting diodes. In the example, an exposure time of one hour makes it possible to obtain a satisfactory disinfection treatment for a motor vehicle air conditioning system air filter. Of course, due to the sequential lighting of the diodes making up the different groups A, B, etc., the total treatment time is greater than the exposure time.

FIG. 3 represents a second embodiment of the invention. In the example of Figure 3, the 48 light-emitting diodes 142 of the disinfection device 14 are divided into twelve groups A, B, C, D, E, F, G, H, I, J K, L of four adjacent diodes. Thus, each of the groups A, B, ..., L comprises a diode from each of the four rows of diodes. By providing for sequential lighting of each of the groups A to L, there are only four diodes lit simultaneously. In such a configuration, it is thus possible to envisage the use of diodes of higher power than those of the example given above. Thus, using diodes whose individual consumption generates an intensity of 500 mA, the consumption of four diodes lit simultaneously is 2 A.

FIG. 4 represents a third embodiment of the invention. In the example of Figure 4, the light-emitting diodes of the disinfection device 14 are divided into two groups A, B of 24 diodes each. Thus the first group A comprises the first two rows of diodes, and the second group B comprises the last two rows. With this distribution, 24 diodes are switched on simultaneously, which, with diodes consuming 50 mA, represents a consumption of 1.2 A.

In the examples of Figures 2 to 4, there is shown a disinfection device in which the light-emitting diodes are distributed in adjacent groups but distinct from each other, which implies that a light-emitting diode belongs to only one group, and that the diode groups are not nested together. However, provision may be made for at least two groups to be nested together. For example, in the case of FIG. 4 which comprises two groups, an example of nested groups would be obtained with a first group comprising the first and third rows of diodes and a second group comprising the second and fourth rows of diodes. Furthermore, one or more diodes may be considered to belong to two groups.

Claims (10)

Process for disinfection by ultraviolet radiation of an element of a motor vehicle air conditioning system (1), such as an air filter (12), the process implementing a disinfection device (14) by ultraviolet radiation comprising a set of light-emitting diodes (142) divided into at least two groups, the method comprising the step of successively activating the ignition of each of the groups of diodes making up the set of light-emitting diodes (142), so that the intensity of the electric current necessary to supply all the light-emitting diodes (142) lit simultaneously is less than or equal to a threshold value, each group of light-emitting diodes (142) being activated for a duration greater than or equal to a minimum exposure time. A method according to claim 1, wherein only one group of light emitting diodes (142) is activated at a time. A method according to claim 1, wherein the array of light-emitting diodes (142) is divided into at least three groups, and wherein two groups of diodes are turned on simultaneously. Disinfection method according to one of the preceding claims, in which each group is distinct from the adjacent group. Method according to one of Claims 1 to 3, in which at least two groups are nested together. Method according to one of the preceding claims, in which the light-emitting diodes (142) all have the same nominal power. Method according to one of the preceding claims, in which the threshold value is between 1 and 2.5 A, preferably between 1.5 and 2.5 A, and for example equal to 2 A. Disinfection device (14) by ultraviolet radiation of an element of a motor vehicle air conditioning system (1), the device comprising a set of light-emitting diodes (142) and a controller (144) arranged to implement the method in accordance with one of the preceding claims. Air conditioning system (1) for a motor vehicle comprising an air filter (12) and a disinfection device (14) according to the preceding claim, the disinfection device (14) being arranged opposite the air filter (12). Motor vehicle comprising an air conditioning system (1) in accordance with the preceding claim.